U.S. patent application number 13/386751 was filed with the patent office on 2012-07-26 for resin composite electrolytic copper foil, copper clad laminate and printed wiring board.
This patent application is currently assigned to PI R&D CO., LTD.. Invention is credited to Norikatsu Akiyama, Eiji Nagata, Akihiro Nomoto, Mitsuru Nozaki, Masashi Yano.
Application Number | 20120189859 13/386751 |
Document ID | / |
Family ID | 43499016 |
Filed Date | 2012-07-26 |
United States Patent
Application |
20120189859 |
Kind Code |
A1 |
Nozaki; Mitsuru ; et
al. |
July 26, 2012 |
RESIN COMPOSITE ELECTROLYTIC COPPER FOIL, COPPER CLAD LAMINATE AND
PRINTED WIRING BOARD
Abstract
The problem of the invention is to provide a resin composite
electrolytic copper foil having further improved heat resistance
and improved plate adhesion strength when plated after desmear
treatment in the work process of an additive method. The solution
is to form a roughened surface having a plurality of minute
projections, a surface roughness (Rz) within a range of 1.0 .mu.m
to 3.0 .mu.m and a lightness value of not more than 30 on one
surface of an electrolytic copper foil, and form a layer of a resin
composition containing a block copolymerized polyimide resin having
a structure that imide oligomers of a first structural unit and a
second structural unit are bonded alternately and repeatedly on the
roughened surface.
Inventors: |
Nozaki; Mitsuru; (Tokyo,
JP) ; Nomoto; Akihiro; (Tokyo, JP) ; Akiyama;
Norikatsu; (Tokyo, JP) ; Nagata; Eiji;
(Yokohama-shi, JP) ; Yano; Masashi; (Yokohama-shi,
JP) |
Assignee: |
PI R&D CO., LTD.
Kanagawa
JP
MITSUBISHI GAS CHEMICAL COMPANY, INC.
Tokyo
JP
|
Family ID: |
43499016 |
Appl. No.: |
13/386751 |
Filed: |
June 25, 2010 |
PCT Filed: |
June 25, 2010 |
PCT NO: |
PCT/JP2010/061291 |
371 Date: |
April 10, 2012 |
Current U.S.
Class: |
428/458 |
Current CPC
Class: |
H05K 1/09 20130101; C25D
1/04 20130101; H05K 2201/0154 20130101; C25D 7/0614 20130101; H05K
1/0373 20130101; C25D 7/0678 20130101; H05K 2203/0307 20130101;
B32B 15/08 20130101; Y10T 428/31681 20150401; C25D 5/022 20130101;
H05K 3/384 20130101; H05K 2201/0355 20130101; H05K 3/4652 20130101;
H05K 1/0346 20130101; H05K 2201/0358 20130101 |
Class at
Publication: |
428/458 |
International
Class: |
B32B 15/08 20060101
B32B015/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 24, 2009 |
JP |
2009-173448 |
Claims
1. A resin composite electrolytic copper foil prepared by forming a
roughened surface having a plurality of minute projections, a
surface roughness (Rz) within a range of 1.0 .mu.m to 3.0 .mu.m and
a lightness value of not more than 30 on one surface of an
electrolytic copper foil (A), and forming a layer of a resin
composition (B) containing a block copolymerized polyimide resin
(a) having a structure that imide oligomers of a first structural
unit and a second structural unit are bonded alternately and
repeatedly on the roughened surface.
2. A resin composite electrolytic copper foil according to claim 1,
wherein in the roughened surface, the volume of a pore with a pore
diameter of 100 to 1000 nm is not less than 0.1 mL/m.sup.2.
3. A resin composite electrolytic copper foil according to claim 1,
wherein the minute projection has a plurality of bored portions on
the lateral when seen in the cross sectional surface along the
thickness direction of the electrolytic copper foil.
4. A resin composite electrolytic copper foil according to claim 1,
wherein the minute projections are located by 200 to 25000 in an
area of 100 .mu.m.times.100 .mu.m.
5. A resin composite electrolytic copper foil according to claim 1,
wherein the weight average molecular weights of the imide oligomers
as the first and the second structural units in the block
copolymerizes polyimide resin (a) are each independently 5000 to
30000.
6. A resin composite electrolytic copper foil according to claim 1,
wherein the block copolymerized polyimide resin (a) is a block
copolymerized polyimide resin (a) having a block of the general
formula (1) as a structural unit and a block of the general formula
(2) as a structural unit. ##STR00004## (In the formulae, m and n
are each not less than 2, and m: n=1:9 to 3:1)
7. A resin composite electrolytic copper foil according to claim 1,
wherein the resin composition (B) contains an inorganic filler
(b).
8. A resin composite electrolytic copper foil according to claim 7,
wherein the resin composition (B) contains the inorganic filler (b)
within a range of 5 to 50% by volume based on total 100% by volume
of the block copolymerized polyimide resin (a) and the inorganic
filler (b).
9. A resin composite electrolytic copper foil according to claim 1,
wherein the resin composition (B) contains a maleimide compound
(c).
10. A resin composite electrolytic copper foil according to claim
9, wherein in the resin composition (B), the content of the block
copolymerized polyimide resin (a) and the maleimide compound (c) is
1:9 to 9:1 in the weight ratio.
11. A resin composite electrolytic copper foil according to claim
9, wherein the maleimide compound (c) is
2,2-bis[4-(4-maleimidephenoxy)phenyl]propane.
12. A resin composite electrolytic copper foil according to claim
1, wherein the thickness of the layer of the resin composition (B)
is 1 .mu.m to 10 .mu.m.
13. A copper clad laminate prepared by layer laminating a resin
composite electrolytic copper foil according to claim 1 and a
B-stage resin composition.
14. A copper clad laminate according to claim 13, wherein the
B-stage resin composition layer contains a resin and an inorganic
filler, and contains the inorganic filler within a range of 5 to
50% by volume based on total 100% by volume of the resin and the
inorganic filler.
15. A copper clad laminate prepared by forming a copper layer with
plating on a surface of a copper clad laminate according to claim
13 where copper is entirely removed.
16. A printed wiring board using a copper clad laminate according
to claim 13.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a resin composite electrolytic
copper foil used in producing a printed wiring board, a copper clad
laminate having the resin composite electrolytic copper foil and a
B-stage resin composition layer laminate molded, a printed wiring
board using the copper clad laminate, and a method for producing
the printed wiring board. More specifically, it relates to a resin
composite electrolytic copper foil having a copper foil with very
small unevenness on a copper foil matt surface applied and being
excellent in adhesion strength to a resin composition, a copper
clad laminate using the resin composite electrolytic copper foil
and having good heat resistance, and a high density printed wiring
board using the copper clad laminate and capable of forming a fine
circuit.
[0003] 2. Description of the Related Art
[0004] In recent years, in order to mount an electronic component
such as a semiconductor part for use in an electronic device, a
printed wiring board has been demanded to further ultrathin its
circuit conductor width and insulating space between circuits, in
combination with ultrahigh densification of a semiconductor
circuit. Also, a solder upon mounting is, since it is lead free for
environmental responsiveness and the mounting temperature becomes
high, required to have further heat resistance.
[0005] Conventionally, as a copper foil of a copper clad laminate
for use in a printed wiring board, an electrolytic copper foil
having remarkable unevenness on a copper foil matt surface and good
copper foil adhesion strength to a resin has been used.
[0006] Although these electrolytic copper foils have good adhesion
strength, there are problems such that when forming a fine circuit
by an etching method, a part of a convex portion of the copper foil
is liable to remain on an insulating resin surface due to influence
of the unevenness on the copper foil matt surface, that as the
etching time is extended in order to completely remove this, the
circuit is over-etched, deteriorating location accuracy of the
circuit and adhesion strength, and the like. As a means for mending
these problems, a so-called low profile copper foil having
suppressed unevenness on a copper foil surface has been put to
practical use. However, when this copper foil is applied to a
copper clad laminate with a highly heat resistant thermosetting
resin and the like having essentially weak adhesion strength, lack
of adhesion strength becomes a problem in a fine circuit, which has
been an obstacle to ultrathinning.
[0007] Also from several years ago, in order to improve the
adhesion strength between a copper foil and an insulating resin, a
method of forming an insulating adhesive layer on a copper foil has
come into practical use. For example, in the case of a paper phenol
resin copper clad laminate, a method of forming an adhesive layer
of phenol butyral resin on a copper foil, in the case of a glass
epoxy resin copper clad laminate, a method of forming an epoxy
resin adhesive on a copper foil, and the like are known. As
specific examples of these resin composite copper foils, a copper
clad laminate using a copper foil having a thin adhesive layer
formed (e.g. see Japanese Patent Application Laid-open Publication
No. 118-216340), a copper clad laminate using a copper foil having
a semi-set resin film bonded (e.g. see Japanese Patent Application
Laid-open Publication No. 119-011397) and the like have been
suggested. However, these resin composite copper foils and copper
clad laminates using a copper foil having a semi-set resin film
bonded have problems in heat resistance, adhesiveness and heat
resistance under moisture absorption, and have required further
improvement.
[0008] Recently, a surface treated copper foil having particles
attached to a surface of a copper foil for improving adhesiveness
(see Japanese Patent Application Laid-open Publication No.
2005-248323) has been suggested. However, in a laminate having this
surface treated copper foil laminated with an insulating heat
resistant thermosetting resin, a fine circuit by an additive method
could not be applied to a high density printed wiring board due to
the problem of lacking the adhesion strength of plated copper.
Moreover, although a resin composite electrolytic copper foil
having a resin composition layer (B) comprising a block
copolymerized polyimide resin (a) and
2,2-bis[4-(4-maleimidephenoxy)phenyl]propane (b) formed (Japanese
Patent Application Laid-open Publication No. 2008-254352) has been
suggested in order to solve this problem, when desmear treatment is
conducted in the work process of the additive method, the plate
adhesion strength was insufficient. In addition, with the
introduction of an environmental responsive lead free solder
containing no lead, further high heat resistance is demanded for
dealing with a lead free solder process conducted at a temperature
higher than before, and improvement has been required.
SUMMARY OF THE INVENTION
[0009] The subject of the invention is to provide a copper clad
laminate, a printed wiring board and a resin composite copper foil
for use in producing the printed wiring board, to provide a resin
composite electrolytic copper foil having further improved heat
resistance and improved plate adhesion strength when plated after
desmear treatment in the work process of an additive method, and to
further allow formation of a fine circuit of a printed wiring board
by using the resin composite electrolytic copper foil.
[0010] The inventors have, as a result of a keen examination for
solving the above problems, found that by using a resin composite
electrolytic copper foil having a layer of particular resin
composition formed on one surface of a particular electrolytic
copper foil, a copper clad laminate suitable for mass production
and excellent in adhesion strength and heat resistance can be
obtained due to a synergistic effect of the surface shape of the
copper foil and the resin composition, and reached at the
invention.
[0011] Thus, the summary of the invention is as follows.
[0012] (1) A resin composite electrolytic copper foil prepared by
forming a roughened surface having a plurality of minute
projections, a surface roughness (Rz) within a range of 1.0 .mu.m
to 3.0 .mu.m and a lightness value of not more than 30 on one
surface of an electrolytic copper foil (A), and forming a layer of
a resin composition (B) containing a block copolymerized polyimide
resin (a) having a structure that imide oligomers of a first
structural unit and a second structural unit are bonded alternately
and repeatedly on the roughened surface.
[0013] (2) A resin composite electrolytic copper foil according to
the above item (1), wherein in the roughened surface, the volume of
a pore with a pore diameter of 100 to 1000 nm is not less than 0.1
mL/m.sup.2.
[0014] (3) A resin composite electrolytic copper foil according to
the above item (1), wherein the minute projection has a plurality
of bored portions on the lateral when seen in the cross sectional
surface along the thickness direction of the electrolytic copper
foil.
[0015] (4) A resin composite electrolytic copper foil according to
the above item (1), wherein the minute projections are located by
200 to 25000 in an area of 100 .mu.m.times.100 .mu.m.
[0016] (5) A resin composite electrolytic copper foil according to
the above item (1), wherein the weight average molecular weights of
the imide oligomers as the first and the second structural units in
the block copolymerized polyimide resin (a) are each independently
5000 to 30000.
[0017] (6) A resin composite electrolytic copper foil according to
the above item (1), wherein the block copolymerized polyimide resin
(a) is a block copolymerized polyimide resin (a) having a block of
the general formula (1) as a structural unit and a block of the
general formula (2) as a structural unit.
##STR00001##
(In the formulae, m and n are each not less than 2, and m:n=1:9 to
3:1)
[0018] (7) A resin composite electrolytic copper foil according to
the above item (1), wherein the resin composition (B) contains an
inorganic filler (b).
[0019] (8) A resin composite electrolytic copper foil according to
the above item (7), wherein the resin composition (B) contains the
inorganic filler (b) within a range of 5 to 50% by volume based on
total 100% by volume of the block copolymerized polyimide resin (a)
and the inorganic filler (b).
[0020] (9) A resin composite electrolytic copper foil according to
the above item (1), wherein the resin composition (B) contains a
maleimide compound (c).
[0021] (10) A resin composite electrolytic copper foil according to
the above item (9), wherein in the resin composition (B), the
content of the block copolymerized polyimide resin (a) and the
maleimide compound (c) is 1:9 to 9:1 in the weight ratio.
[0022] (11) A resin composite electrolytic copper foil according to
the above item (9), wherein the maleimide compound (c) is
2,2-bis[4-(4-maleimidephenoxy)phenyl]propane.
[0023] (12) A resin composite electrolytic copper foil according to
the above item (1), wherein the thickness of the layer of the resin
composition (B) is 1 .mu.m to 10 .mu.m. (13) A copper clad laminate
prepared by layer laminating a resin composite electrolytic copper
foil according to any of the above items (1) to (12) and a B-stage
resin composition layer.
[0024] (14) A copper clad laminate according to the above item
(13), wherein the B-stage resin composition layer contains a resin
and an inorganic filler, and contains the inorganic filler within a
range of 5 to 50% by volume based on total 100% by volume of the
resin and the inorganic filler.
[0025] (15) A copper clad laminate prepared by forming a copper
layer with plating on a surface of a copper clad laminate according
to the above item (13) or (14) where copper is entirely
removed.
[0026] (16) A printed wiring board using a copper clad laminate
according to any of the above items (13) to (15).
[0027] A resin composite electrolytic copper foil obtained in the
invention can, since the adhesion strength of a copper clad
laminate to a resin composition is excellent, have an electrolytic
copper foil with small unevenness on a copper foil matt surface,
roughened by attaching roughening particles, applied, and by using
this resin composite electrolytic copper foil, a copper clad
laminate with good economic efficiency and heat resistance under
moisture absorption can be obtained. Since this copper clad
laminate can be preferably used as a high density printed wiring
board with a fine circuit, is particularly excellent in the
adhesion strength of plated copper after desmear treatment and have
further improved heat resistance, industrial practicality of the
resin composite electrolytic copper foil of the invention is
extremely high.
BRIEF DESCRIPTION OP THE DRAWINGS
[0028] The invention will be described with reference to the
accompanying drawings, wherein:
[0029] FIG. 1 is a graph showing the relationship between the pore
diameter (.mu.m) of a pore formed on a roughened surface of an
electrolytic copper foil and the pore volume per unit area
(ml/m.sup.2) of an electrolytic copper foil with a plurality of
minute projections;
[0030] FIG. 2 is an enlarged photo showing a cross sectional
surface of an electrolytic copper foil of the invention;
[0031] FIG. 3 is an enlarged photo showing a cross sectional
surface of an electrolytic copper foil of the invention;
[0032] FIG. 4 is an enlarged photo showing a cross sectional
surface of a conventional electrolytic copper foil;
[0033] FIG. 5 is a schematic cross section view of an electrolytic
copper foil of the invention; and
[0034] FIG. 6 is a schematic cross section view of a conventional
electrolytic copper foil.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] An electrolytic copper foil used in the invention can be
obtained by conducting electrolytic treatment using a plating
solution for surface roughening treatment and the like. The surface
roughness Rz of the electrolytic copper foil is required to be
within a range of 1.0 to 3.0 .mu.m. The one with an Rz of less than
1.0 .mu.m cannot achieve the subject of the invention due to low
peel strength, and also the one with an Rz of more than 3.0 .mu.m
is inadequate in terms of high frequency property and fine
patterning.
[0036] Moreover, an electrolytic copper foil in the invention is
required to have a lightness value of not more than 30. The
lightness in the invention is a lightness usually used as an index
showing surface roughness, and the measurement method thereof is a
method of irradiating a measurement sample surface and measuring
the light reflection amount to be represented as a lightness value.
As the lightness of a treated surface of an electrolytic copper
foil is measured by this method, the tendency is that when the Rz
as surface roughness is large or a groove between roughening
particles is deep, the light reflection amount becomes small so the
lightness value becomes low, and when the surface is flat and
smooth, the light reflection amount becomes large so the lightness
becomes high. In order to improve the peel strength with a
polyimide resin in the invention, the lightness should be not more
than 30.
[0037] Here, regarding the lightness measurement, the lightness was
measured with a light meter (made by Suga Test Instruments Co.,
Ltd., model name: SM Color Computer, model number: SM-4) after
conducting anti-rust treatment within a range of
[0038] Ni: 0.01 to 0.5 mg/dm.sup.2
[0039] Zn: 0.01 to 0.5 mg/dm.sup.2
[0040] Cr: 0.01 to 0.3 mg/dm.sup.2
to a copper foil to be measured.
[0041] In the invention, for the purpose of obtaining excellent
peel strength and fine patterning property, the electrolytic copper
foil has a plurality of minute projections on one surface. Although
the minute projection is not limited to particular conditions as
long as it meets the above ranges for the surface roughness and the
lightness of the roughened surface of the electrolytic copper foil,
its shape is, when seen in the cross sectional surface along the
thickness direction of the electrolytic copper foil, preferable to
have a plurality of bored portions on a side surface from the
perspective that more excellent peel strength can be obtained by
the synergistic effect with a layer of resin composition to be
described below.
[0042] Here, FIG. 2 is an enlarged photo showing a cross sectional
surface of an electrolytic copper foil of the invention, and FIGS.
5 (a) and (b) is a view schematically showing a cross sectional
surface of an electrolytic copper foil of the invention. The bored
portion of the minute projections is, as shown in FIG. 5 (a), a
portion 10a bored inward in the width direction among side surfaces
of the minute projection 10. Since difference in diameter is
generated between the upper end and the root portion of a minute
projection by forming the bored portion 10a, high anchor effect
with a resin composition formed on the electrolytic copper foil is
exerted, resulting in improvement of peel strength. The way of
being bored of the bored portion 10a is not particularly limited as
long as it is bored inward in the width direction of the minute
projection when seen in a cross sectional surface along the
thickness direction of the electrolytic copper foil, and as shown
in FIGS. 5 (a) and (b), it is possible to have bored portions 10a
with various shapes. In addition, from the actual photo shown in
FIG. 2, it is also clear that the minute projection has a plurality
of bored portions.
[0043] On the other hand, as shown in FIG. 6, it is clear that a
cross sectional surface of a conventional electrolytic copper foil
is greatly different in shape from an electrolytic copper foil of
the invention with minute projections 10 having bored portions 10a.
This can also be seen by comparing an enlarged photo showing a
cross sectional surface of a conventional electrolytic copper foil
shown in FIG. 4 and a photo of a cross sectional surface of an
electrolytic copper foil of the invention shown in FIG. 2.
[0044] Moreover, the height of the minute projection is preferable
to be 1.0 .mu.m to 5.0 .mu.m. It is because the effect of
increasing peel strength cannot be obtained with a height of less
than 1.0 .mu.m, while variation in Rz increases, peel strength
cannot be kept stable, high frequency property decreases, and it is
liable to be unsuitable for fine patterning with a height of more
than 5.0 .mu.m. It should be noted that the height described herein
refers to, as shown in FIG. 5 (a), a distance H between a surface
of a portion without the minute projection and a vertex of the
minute projection 10 in a copper foil.
[0045] Furthermore, in the roughened surface of the electrolytic
copper foil, the volume of pores with a diameter of 100 to 1000 nm
is preferable to be not less than 0.1 mL/m.sup.2 from the point of
obtaining more excellent peel strength. When the volume of pores is
less than 0.1 mL/m.sup.2, the volume of pores is too small and the
amount of the resin composition (B) entering into the pores becomes
small, which could lead to the problem that sufficiently desirable
peel strength cannot be ensured. Here, the pore refers to, as shown
in FIG. 5 (b), a portion where a minute projection is not formed,
which becomes as a result of that the minute projections are formed
on a surface of a copper foil.
[0046] Here, FIG. 1 is a graph showing the relationship between the
pore diameter (nm) of the pores and the pore volume per unit area
(mL/m.sup.2). From FIG. 1, it is clear that in a roughened surface
of a copper foil of the invention, the volume of pores with a pore
diameter of 100 to 1000 nm is not less than 0.01 mL/m2, which is
larger than a roughened surface of a conventional copper foil.
[0047] In addition, a method for measuring the above pore volume is
not particularly limited as long as it is a method capable of
certainly measuring the volume of pores with a pore diameter of 100
to 1000 nm. For example, it can be measured with an instrument:
Shimadzu Autopore III 9400 series (made by Shimadm
Corporation).
[0048] Moreover, regarding the number of minute projections,
desired peel strength cannot be exerted with few, while the effect
decreases conversely even with many due to weak adhesiveness
between a copper foil surface and minute projections. The number of
minute projections on a copper foil surface in the invention is
preferable to be 200 to 25000 present in an area of 100
.mu.m.times.100 .mu.m. When the number of minute projections is
less (less than 200), space between minute projections becomes wide
and fine patterning is liable to be impossible, and when it is more
than 25000, distance between minute projections becomes narrow and
the peel strength is liable to deteriorate.
[0049] Additionally, in the invention, the number of the minute
projections is preferably 6 to 35, in particular most preferably 10
to 20 present in the observation field width of a cross sectional
surface of 25 .mu.m.
[0050] Furthermore, by substantially evenly distributing 6 to 35
minute projections with a height of 1.0 .mu.m to 5.0 .mu.m present
within the observation field width of a cross sectional surface of
25 .mu.m for forming grooves with a depth of not less than 0.3
.mu.m, it can be avoided to have minute projections partially
focused within 25 .mu.m and the peel strength can be stabilized in
the width direction/longitudinal direction of a copper foil. It
should be noted that "substantially evenly distributed" refers to,
for example, the case in which when the number of minute
projections with the height between the vertex of the minute
projection and the copper foil surface of 1.0 to 5.0 .mu.m is n and
the observation width when minute projections are observed in a
cross sectional surface is 25 (.mu.m), one portion of at least one
of the minute projections exists in an area with the width of 25/n
(.mu.m).
[0051] In addition, roughening particles for forming the minute
projections are not particularly limited to any conditions other
than that the main component is Cu. For example, Cu or alloy
particles of Cu and Mo, or ones containing Cu and at least one kind
of elements selected from the group of Ni, Co, Fe, Cr, V and W can
be used.
[0052] Cu particles or alloy particles of Cu and Mo, which can form
a minute projection with further uniformity, are more effective.
These roughening particles for forming a minute projection are
thought to increase peel strength since they bind chemically to a
resin. Particles for increasing peel strength by chemical binding
can include Cu--Mo alloy, Cu--Ni alloy, Cu--Co alloy, Cu--Fe alloy,
Cu--Cr alloy, Cu--Mo--Ni alloy, Cu--Mo--Cr alloy, Cu--Mo--Co alloy,
Cu--Mo--Fe alloy and the like, but according to resin species.
[0053] At least of one kind of element selected from the group of
Mo, Ni, Fe, Cr, V and W contained in alloy particles for forming
the minute projection is preferable to take up 0.01 ppm to 20% by
weight based on the amount of Cu present. It is because of that an
alloy composition where the amount thereof present is more than 20%
by weight becomes difficult to dissolve upon etching a circuit
pattern in a post process.
[0054] Moreover, it is better to provide a metal plating layer of
at least one kind selected from the group of Ni, Ni alloy, Zn, Zn
alloy, Ag on a surface with minute projections for the purpose of
improving powder fall property, resistance to hydrochloric acid,
heat resistance and conductivity. Furthermore, it is better to
attach a metal plating layer of at least one kind of Ni, Ni alloy,
Zn, Zn alloy, Ag also to a surface not provided with minute
projections for the purpose of improving resistance to hydrochloric
acid, heat resistance and conductivity. In order to achieve these
purposes, the amount of metal attached is desirable to be not less
than 0.05 mg/dm.sup.2, not more than 10 mg/dm.sup.2.
[0055] Anti-rust treatment by forming a Cr and/or chromate coating
on a foil of a roughened surface of the above structure, or
according to the need, silane coupling treatment or anti-rust
treatment and silane coupling treatment is conducted.
[0056] A block copolymerized polyimide resin used in a resin
composite copper foil of the invention is not particularly limited,
as long as it has a structure that imide oligomers of a first
structural unit and a second structural unit are bonded alternately
and repeatedly. In terms of solder heat resistance under moisture
absorption, the weight average molecular weights of imide oligomers
of the first and the second structural unit are each preferable to
be not less than 5000, and in terms of molecular weight
controllability (easiness of controlling molecular weight) and
application property (easiness of application), the weight average
molecular weights of imide oligomers of the first and the second
structural unit are each preferable to be not more than 30000
independently.
[0057] A block copolymerized polyimide resin (a) used in the
invention is particularly preferable to be a block copolymerized
polyimide resin (a) having structural units represented by the
general formula (1) and the general formula (2). The reason is that
it is excellent in chemical resistance, adhesion strength and
solder heat resistance under moisture absorption. A tetracarboxylic
dianhydride used in this block copolymerized polyimide resin (a) is
3,4,3',4'-biphenyl tetracarboxylic dianhydride, and diamines are
1,3-bis(3-aminophenoxy)benzene and
2,2-bis[4-(4-aminophenoxy)phenyl]propane.
##STR00002##
(In the formulae, m and n are each not less than 2, and m: n=1:9 to
3:1)
[0058] Also, in order to control the molecular weight of each unit
polycondensate, by shifting the molar ratio of the tetracarboxylic
dianhydride and the diamine upon the first stage reaction, having
an acid anhydride or an amine at the end, and making the molar
ratio of the tetracarboxylic dianhydride and another diamine or of
another tetracarboxylic dianhydride and the diamine reverse to the
first stage in the second stage reaction, it is possible to obtain
a block copolymerized polyimide with a sufficient molecular
weight.
[0059] The weight average molecular weight (Mw) of the entire block
copolymerized polyimide resin (a) of the invention is desirable to
be 50000 to 300000. More preferably, it is 80000 to 200000. When
the Mw is less than 50000, a polyimide resin layer becomes fragile
and is liable to be unable to be used for the object. On the other
hand, when the Mw is more than 300000, the solution viscosity
becomes too high and coating is liable to become difficult.
Moreover, in order to control the final molecular weight, it is
also possible to synthesize it by shifting the molar ratio of the
tetracarboxylic dianhydride and the diamine to be used. The molar
ratio of each of unit polycondensates of the general formula (1)
and the general formula (2) is general formula (1): general formula
(2) 1:9 to 3:1. More preferably, it is general formula (1): general
formula (2)=1:3 to 3:1. When the rate of the structure of the
general formula (1) becomes less than 10 mole %, decrease in
adhesion strength is liable to be a problem, and when the rate of
the structure of the general formula (2) becomes less than 25 mole
%, decrease in solder heat resistance is liable to be a
problem.
[0060] These block copolymerized polyimide resins are synthesized
in a polar solvent by reacting a tetracarboxylic dianhydride with a
diamine into an imide oligomer, and further adding the
tetracarboxylic dianhydride and another diamine, or another
tetracarboxylic dianhydride and the diamine to occur polymerization
reaction for imidization one after another. In this regard, the
weight average molecular weight of the initial imide oligomer is
preferable to be 5000 to 30000.
[0061] A polar solvent to be used includes a polar solvent which
dissolves polyimide, such as N-methyl-2-pyrrolidone,
dimethylacetamide, dimethylformamide, dimethyl sulfoxide,
sulfolane, and tetramethylurea. Additionally, it is also possible
to use a mixture of ketone based or ether based solvents, and as
ketone based solvents, methyl ethyl ketone, methyl propyl ketone,
methyl isopropyl ketone, methyl butyl ketone, methyl isobutyl
ketone, methyl-n-hexyl ketone, diethyl ketone, diisopropyl ketone,
diisobutyl ketone, cyclopentanone, cyclohexanone,
methylcyclohexanone, acetylacetone, diacetone alcohol,
cyclohexene-n-one, and as ether based solvents, dipropyl ether,
diisopropyl ether, dibutyl ether, tetrahydrofuran, tetrahydropyran,
ethyl isoamyl alcohol, ethyl-t-butyl ether, ethyl benzyl ether,
diethylene glycol dimethyl ether, cresyl methyl ether, anisole,
phenetole are usable. Also, in order to remove water produced upon
imidization reaction, it is required to add a solvent which
azeotropes with water such as toluene and xylene to remove water
out of the system. Moreover, in order to promote the reaction, an
amine based catalyst such as pyridine and a two-component based
catalyst of a base and a cyclic ester such as pyridine and
.gamma.-valerolactone are preferably used. With the reaction
temperature of 120 to 200.degree. C., it is possible to obtain a
polar solvent solution of only block copolymerized polyimide resin
by eventually removing a solvent which azeotropes with water such
as toluene and xylene and a catalyst such as pyridine out of the
system.
[0062] An inorganic filler (b) contained in the block copolymerized
polyimide resin (a) of the invention is not particularly limited as
long as it is generally used, but the specific examples include
silicas such as natural silica, molten silica, amorphous silica and
hollow silica, metal hydrates such as aluminum hydroxide, heat
treated product of aluminum hydroxide (wherein aluminum hydroxide
is heat treated and crystal water is partially reduced), boehmite
and magnesium hydroxide, molybdenum compounds such as molybdenum
oxide and zinc molybdate, titanium oxide, barium titanate, barium
sulphate, zinc borate, zinc stannate, alumina, clay, kaolin, talc,
calcined clay, calcined kaolin, calcined talc, mica, glass short
fiber (fine glass powers of E-glass, D-glass, etc.), hollow glass,
whisker, and the like. Preferably, the above mentioned silicas,
metal hydrates such as aluminum hydroxide, heat treated product of
aluminum hydroxide (wherein aluminum hydroxide is heat treated and
crystal water is partially reduced), boehmite and magnesium
hydroxide, talc, calcinated talc, and the like are used. These are
used as one kind or in combination of two kinds or more
accordingly. The amount of the inorganic filler contained is not
particularly limited, but preferable to be within a range of 5 to
50% by volume based on total 100% by volume of the block
copolymerized polyimide resin (a) and the inorganic filler (b) in
terms of heat resistance. More preferably, it is better to be not
less than 19% by volume, not more than 40% by volume. Even more
preferably, it is better to be not less than 19% by volume, not
more than 30% by volume. Moreover, in order to evenly disperse the
inorganic filler (b) in the block copolymerized polyimide resin
(a), it is preferable to use various dispersers. Furthermore, in
order to enhance close adherence between the inorganic filler (b)
and the block copolymerized polyimide resin (a), it is also
effective to treat the inorganic filler (b) with a coupling agent
such as a slime coupling agent and add a suitable amount of the
coupling agent to the resin. The average particle size of the
inorganic filler (b) is preferable to be not more than 4 .mu.m, and
more preferable to be not more than 1 .mu.m, in terms of uniformity
of the block copolymerized polyimide resin (a).
[0063] A maleimide compound (c) used in the block copolymerized
polyimide resin (a) of the resin composite copper foil of the
invention is not particularly limited, as long as it is a compound
having two or more maleimide groups in one molecule. Preferably,
bis(4-maleimidephenyl)methane, polyphenyl methane maleimide,
m-phenylene bismaleimide, bisphenol A diphenyl ether
bismaleimide(2,2'-bis[4-(4-maleimidephenoxy)phenyl]propane),
3,3'-dimethyl-5,5'-diethyl-4,4'-diphenyl methane bismaleimide,
4-methyl-1,3-phenylene bismaleimide are included, and more
preferably, bisphenol A diphenyl ether
bismaleimide(2,2'-bis[4-(4-maleimidephenoxy)phenyl]propane) is
included. It is also possible to use one kind of the maleimide
compounds or a combination of two kinds or more accordingly.
Moreover, it is also possible to use a prepolymer of a maleimide
compound, or a prepolymer of a maleimide compound and an amine
compound A 2,2-bis[4-(4-maleimidephenoxy)phenyl]propane (d) used in
the resin composition (B) of the resin composite electrolytic
copper foil of the invention is represented by the chemical formula
(3).
##STR00003##
[0064] The content ratio of the block copolymerized polyimide (a)
and the maleimide compound (c) in the resin layer of the resin
composite copper foil is preferable to be within a range of 1:9 to
9:1 in the weight ratio, and more preferable content ratio is 60;
40 to 40:60 in the weight ratio.
[0065] The thickness of resin composition (B) of the resin
composite electrolytic copper foil of the invention can be adjusted
according to the surface roughness level of the copper foil, and is
preferable to be 1 to 10 .mu.m. When the thickness is more than 10
.mu.m, drying in the heating step after the copper foil coating is
liable to be insufficient and the heat resistance of the copper
clad laminate used may decrease. When the thickness is less than 1
.mu.m, many craters are liable to occur in the copper foil coating.
In addition, the thickness is particularly more preferable to be 1
to 5 .mu.m.
[0066] As a preparation example of the resin composite copper foil
of the invention, it is prepared by adding the maleimide compound
(c) if needed to a polar solvent solution of the block
copolymerized polyimide resin (a) obtained in the synthesis method
described above and stirring, dispersing the inorganic filler (b)
in a publicly known method, directly coating it on a roughened
surface of the copper foil, and drying. As a coating method,
various methods such as reverse roll, rod (bar), blade, knife, die,
gravure, and rotary screen are possible. For drying, a hot wind
dryer, an infrared ray dryer and the like can be used, but not
particularly limited thereto as long as it can heat to a
temperature sufficient enough to remove the solvent used. Moreover,
in order to prevent oxidation of the copper foil, methods of drying
at a temperature not more than 200.degree. C. for a long time, and
drying at a further higher temperature under vacuum or an inert
atmosphere such as nitrogen are also possible.
[0067] A resin composition used in the B-stage resin composition
layer capable of being preferably laminate molded with the resin
composite electrolytic copper foil of the invention is not
particularly limited, as long as it is a publicly known
thermosetting resin composition for use in a printed wiring board.
These resins include epoxy resin, polyimide resin, cyanate ester
resin, maleimide resin, double bond added polyphenylene ether
resin, resin compositions of thereof with bromine and phosphorus
containing compounds and the like for example, and one kind or a
combination of two kinds or more is used. A resin composition
having a cyanate ester resin as an essential component is
preferably used in a combination with, for example, an epoxy resin
and the like, in terms of reliability of migration resistance, heat
resistance and the like. It is possible to use a publicly known
catalyst, setting agent and setting accelerator, if needed, to
these thermosetting resins.
[0068] The cyanate ester resin preferably used in the resin
composition used in the B-stage resin composition layer is a
compound having two or more cyanato groups within a molecule.
Specific examples are 1,3- or 1,4-dicyanato benzene,
1,3,5-tricyanato benzene, 1,3-, 1,4-, 1,6-, 1,8-, 2,6- or
2,7-dicyanato naphthalene, 1,3,6-tricyanato naphthalene,
4,4-dicyanatobiphenyl, bis(4-dicyanatophenyl)methane,
2,2-bis(4-cyanatophenyl)propane,
2,2-bis(3,5-dibromo-4-cyanatophenyl)propane,
bis(4-cyanatophenyl)ether, bis(4-cyanatophenyl)thioether,
bis(4-cyanatophenyl)sulfone, tris(4-cyanatophenyl)phosphite,
tris(4-cyanatophenyl)phosphate, cyanates obtained by reaction of a
novolac and a cyanogen halide, and the like.
[0069] Other than these, phenol novolac type cyanate ester
compounds described in Japanese Examined Patent Application
Publication No, 541-1928, Japanese Patent Application Laid-open
Publication Nos. 543-18468, 544-4791, 545-11712, 546-41112,
547-26853 and 551-63149, and the like can also be used. Moreover,
naphthalene type cyanate ester compounds can also be used.
Furthermore, a prepolymer with a molecular weight of 400 to 6000
having a triazine ring formed by trimerization of a cyanato group
of these cyanate ester compounds is used. This prepolymer can be
obtained by polymerizing the above cyanate ester monomers with a
catalyst including acids such as mineral acid and Lewis acid; bases
such as sodium alcolates and tertiary amines; salts such as sodium
carbonate for example. This resin contains a partially unreacted
monomer in the form of a mixture of a monomer and a prepolymer, and
such material is preferably used in the application of the
invention. Furthermore, a cyanated polyphenylene ether resin can
also be used. A monofunctional cyanate ester compound can also be
added to these in an amount which does not significantly affect
properties. It is preferably 1 to 10% by weight. These cyanate
ester resins are not limited to the above, but publicly known ones
are usable. These are used as one kind or in combination of two
kinds or more accordingly.
[0070] As an epoxy resin preferably used in combination with the
cyanate ester resin, publicly known one can be used. Specifically,
bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol
novolac type epoxy resin, cresol novolac type epoxy resin,
alicyclic epoxy resin, biphenyl type epoxy resin, fluorene type
epoxy resin, resorcinol type epoxy resin, naphthalene type epoxy
resin, phenol aralkyl type epoxy resin, biphenyl aralkyl type epoxy
resin, epoxidized polyphenylene ether resin; polyepoxy compounds
having epoxidized double bonds of butadiene, pentadiene, vinyl
cyclohexene, dicyclopentyl ether and the like; polyol, polyglycidyl
compounds obtained by reaction of hydroxyl group containing
silicone resins and an epichlorohydrin, and the like are included.
Also, publicly known bromine added resins, phosphorous containing
epoxy resin, and the like thereof are included. These are used as
one kind or in combination of two kinds or more accordingly.
[0071] As a phenolic resin used in the B-stage resin composition
layer, publicly known one can be used. Specifically, novolac type
phenolic resin, cresol type phenolic resin, aryl alkylene type
phenolic resin, and the like are included. Also, publicly known
bromine added resins, phosphorous containing resin, and the like
thereof are included. These are used as one kind or in combination
of two kinds or more accordingly.
[0072] In the resin composition used in the B-stage resin
composition layer, various additives can be contained if desired
within the range where the original properties of the composition
are not deteriorated. As these additives, polymerized double bond
containing monomers such as unsaturated polyester and prepolymers
thereof; low molecular weight liquid to high molecular weight
elastic rubbers such as polybutadiene, maleinated butadiene,
butadiene-acrylonitrile copolymer, polychloroprene,
butadiene-styrene copolymer, polyisoprene, butyl rubber, fluorine
rubber, and natural rubber; polyethylene, polypropylene,
polybutene, poly-4-methylpenten, polystyrene, AS resin, ABS resin,
MBS resin, styrene-isoprene rubber, acryl rubber, core shell rubber
thereof, polyethylene-propylene copolymer, 4-fluorinated
ethylene-6-fluorinated ethylene copolymers; high molecular weight
prepolymer or oligomer such as polycarbonate, polyphenylene ether,
polysulfone, polyester, and polyphenylene sulfide; polyurethane,
and the like are exemplified, and used accordingly. Also, other
than these, various additives such as publicly known organic
filler, inorganic filler, dye, pigment, thickener, lubricant,
defoamer, disperser, leveling agent, photosensitizer, flame
retardant, brightener, polymerization inhibitor, and thixotropic
agent are used in combination accordingly if desired. If needed, a
setting agent and a catalyst are contained accordingly in a
compound having a reactive group.
[0073] Particularly when processing such as piercing is conducted
by carbon dioxide gas laser, in order to have a good hole shape, it
is preferable to add an inorganic filler to the B-stage resin
composition layer. As an inorganic filler, the same one to the
inorganic filler (b) contained in the block copolymerized polyimide
resin (a) of the invention can be used, and preferably silicas such
as molten silica, metal hydrates such as aluminum hydroxide, heat
treated product of aluminum hydroxide (wherein aluminum hydroxide
is heat treated and crystal water is partially reduced), boehmite
and magnesium hydroxide, talc, calcinated talc, and the like axe
used. These are used as one kind or in combination of two kinds or
more accordingly, and the amount of the inorganic filler (b)
contained is not particularly limited, but preferable to be within
a range of 5 to 50% by volume in total 100% by volume of the
B-stage resin and the inorganic filler used in the B-stage resin
composition layer, in terms of processability by carbon dioxide gas
laser. More preferably, it is better to be 10 to not more than 40%
by volume. Even more preferably, it is better to be not less than
15% by volume, not more than 30% by volume.
[0074] A method for preparing the B-stage resin composition layer
used in the invention is not particularly limited, but it is
prepared in publicly known methods such as a method of preparing a
varnish by dissolving/dispersing a thermosetting resin composition
in a solvent or without any solvent, applying it to one surface of
a mold release film and drying it to form a B-stage resin
composition sheet, and a method of applying it to a base material,
drying and B-staging to form a prepreg, a method of directly
applying it onto a substrate having a conductive circuit formed and
drying it to form a B-stage resin composition layer, for example.
The thickness of this B-stage resin composition layer is not
particularly limited, but in the case of sheet, it is preferably 4
to 150 .mu.m, and it is also the same in the case of application.
In the case of prepreg, the thickness is preferably 10 to 200
.mu.m.
[0075] For the B-stage resin composition layer used in the
invention, it is preferable to use a base material in terms of the
property of the resulting copper clad laminate. A base material to
be used is not particularly limited, as long as it is a publicly
known base material for use in a printed wiring board.
Specifically, a nonwoven cloth, a woven cloth and the like of
generally and publicly known glass fibers such as E, NE, D, S and
T-glasses are included. These base materials are preferable to be
subjected to publicly known surface treatment so as to improve
close adherence to the resin composition.
[0076] Moreover, a method for producing a copper clad laminate in
the invention is to arrange the resin composition layer surface of
the resin composite copper foil opposing the above B-stage resin
composition layer and to laminate mold. Specifically, a copper clad
laminate is produced by arranging the resin composition layer
surface of the above resin composite electrolytic copper foil
opposing on at least one surface of the B-stage resin composition
layer or the laminate with an inner layer circuit formed having the
B-stage resin composition layer arranged or formed on both
surfaces, heating, pressurizing, and laminate molding preferably
under vacuum. A printed wiring board of the invention is produced
by forming a conductive circuit on these copper clad laminate and
multilayer copper clad laminate in a publicly known method, and
then conducting plating treatment and the like.
[0077] The kind of laminates with an inner layer circuit formed for
use in these is not particularly limited, and a publicly known
laminate, a metal foil clad board, preferably a copper clad board
for a printed wiring board material can be used. Specifically,
publicly known ones such as an inorganic fiber and/or organic fiber
base material copper clad laminate, a heat resistant film base
material copper clad board using a thermosetting resin composition
and/or a thermoplastic resin composition, further a composite base
material copper clad laminate in combination of these base
materials and a multilayer copper clad board thereof, and a
multilayer copper clad board prepared by the additive method can be
used. The conductor thickness of the inner layer circuit substrate
is not particularly limited, but is preferably 3 to 35 .mu.m. This
conductive circuit is preferable to be subjected to publicly known
treatments for enhancing close adherence to the resin of the
B-stage resin composition layer, such as black copper oxide
treatment and liquid chemical treatment (e.g. CZ treatment by
MEC).
[0078] Lamination conditions of the invention are not particularly
limited, but are preferably laminate molding at a temperature of
100 to 250.degree. C., a pressure of 5 to 40 kgf/cm.sup.2 and a
degree of vacuum of not more than 30 mmHg for about 30 minutes to 5
hours. Although lamination may be conducted under this condition
from the beginning to the end, it is also possible to laminate mold
until gelation of the B-stage resin composition layer and then take
out for post-setting in a furnace.
[0079] A method for producing the printed wiring board of the
invention is not particularly limited, but the following methods
are preferable. The above copper clad laminate is used, piercing of
throughholes and blind vias is conducted with a drill, laser and
the like, desmear treatment is conducted with permanganates, if
needed, to prepare a perforated copper clad laminate, the copper
foil is entirely removed by etching, and then electroless copper
plating is conducted without conducting roughening treatment on the
exposed resin composition layer surface of the laminate.
Alternatively, the above copper clad laminate of the invention is
used, the copper foil is entirely removed by etching, piercing of
throughholes and blind vias is conducted with a drill, laser and
the like, desmear treatment is conducted with permanganates, if
needed, and electroless copper plating is conducted. In addition,
an etching removal method is not particularly limited in the kinds
of etching solutions, and a publicly known method is
applicable.
[0080] Generally, a copper layer preferably with a thickness of 0.5
to 2 .mu.m is formed by forming a palladium catalyst on the resin
film surface, and then immersing it in an electroless copper
plating solution. Next, a strongly adhered copper circuit is formed
by conducting electrolytic copper plating on the entire surface and
etching, or a strongly adhered copper circuit is formed by
selectively attaching electrolytic copper plating and etching to
remove a thickness portion of at least the electroless copper
plated layer. The thickness of the electrolytic copper plating is
optionally selected. In this regard, for further improving the
adhesion strength of the copper plated layer, it is preferable to
heat treat the electroless copper plated layer at 100.degree. C. to
200.degree. C. after formation. The heating time is not
particularly limited, but is preferably selected from 30 minutes to
5 hours. It is preferable to heat under vacuum and an inert gas for
preventing oxidation of the copper foil.
[0081] A method for forming a copper circuit thereafter is
conducted according to a publicly known subtractive method or
pattern plating method to prepare a printed wiring board.
Specifically, in the case of patterning by the subtractive method,
a printed wiring board is prepared by coating a portion where a
copper circuit is to be formed on a copper plated layer with an
etching resist, and selectively removing the copper plated layer by
a publicly known etching method to form a circuit pattern.
Moreover, in the case of patterning by the pattern plating method,
a printed wiring board is prepared by forming an electroless copper
plated layer of about 0.5 to 1 .mu.m, selectively coating other
than the site where a copper circuit is to be formed with a plating
resist, forming an electrolytic copper plated layer of about 10 to
30 .mu.m, peeling the plating resist, and etching at least the
electroless copper plated layer where the electrolytic copper
plated layer is not formed to form a pattern.
EXAMPLES
[0082] The invention will be described specifically in Synthesis
Examples, Comparative Synthesis Examples, Examples and Comparative
Examples below. However, the invention is not limited to these
examples. It should be noted that "parts" refers to the number of
parts by weight in the solid content, unless otherwise stated.
Synthesis Example 1
[0083] To a 2 L three neck flask having a reflux cooler equipped
with a ball cooling tube mounted on a trap with an anchor shaped
stirring stick, a nitrogen introducing tube and a stop cock of
stainless steel, 117.68 g (400 mmol) of 3,4,3',4'-biphenyl
tetracarboxylic dianhydride, 87.7 g (300 mmol) of
1,3-bis(3-aminophenoxy)benzene, 4.0 g (40 mmol) of
.gamma.-valerolactone, 4.8 g (60 mmol) of pyridine, 300 g of
N-methyl-2-pyrrolidone (hereinafter referred to as NMP) and 20 g of
toluene were added, heated at 180.degree. C. for 1 hour and then
cooled to about room temperature, and subsequently 29.42 g (100
mmol) of 3,4,3',4'-biphenyl tetracarboxylic dianhydride, 82.12 g
(200 mmol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 200 g of
NMP and 40 g of toluene were added, mixed at room temperature for 1
hour and then heated at 180.degree. C. for 3 hours to obtain a
block copolymerized polyimide resin with a solid content of 38%. In
this block copolymerized polyimide resin, general formula (1):
general formula (2)=3:2, number average molecular weight: 70000,
weight average molecular weight: 150000. Also, the weight average
molecular weight of a block of imide oligomers of a structural unit
represented by the general formula (1) was 7000. This block
copolymerized polyimide resin solution was further diluted with NMP
into a block copolymerized polyimide resin solution with a solid
content of 15% to obtain a block copolymerized polyimide (a1).
Synthesis Example 2
[0084] To a 2 L three neck flask having a reflux cooler equipped
with a ball cooling tube mounted on a trap with an anchor shaped
stirring stick, a nitrogen introducing tube and a stop cock of
stainless steel, 117.68 g (400 mmol) of 3,4,3',4'-biphenyl
tetracarboxylic dianhydride, 123.18 g (300 mmol) of
2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4.0 g (40 mmol) of
.gamma.-valerolactone, 4.8 g (60 mmol) of pyridine, 300 g of NMP
and 20 g of toluene were added, heated at 180.degree. C. for 1 hour
and then cooled to about room temperature, and subsequently 29.42 g
(100 mmol) of 3,4,3',4'-biphenyl tetracarboxylic dianhydride, 58.47
g (200 mmol) of 1,3-bis(3-aminophenoxy)benzene, 200 g of NMP and 40
g of toluene were added, mixed at room temperature for 1 hour and
then heated at 180.degree. C. for 3 hours to obtain a block
copolymerized polyimide resin with a solid content of 38%. In this
block copolymerized polyimide resin, general formula (1): general
formula (2)=2:3, number average molecular weight: 75000, weight
average molecular weight: 160000. Also, the weight average
molecular weight of a block of imide oligomers of a structural unit
represented by the general formula (2) was 8000. This block
copolymerized polyimide resin solution was further diluted with NMP
into a block copolymerized polyimide resin solution with a solid
content of 15% to obtain a block copolymerized polyimide (a2).
Synthesis Example 3
[0085] To a 2 L three neck flask having a reflux cooler equipped
with a ball cooling tube mounted on a trap with an anchor shaped
stirring stick, a nitrogen introducing tube and a stopcock of
stainless steel, 117.68 g (400 mmol) of 3,4,3',4'-biphenyl
tetracarboxylic dianhydride, 73.08 g (250 mmol) of
1,3-bis(3-aminophenoxy)benzene, 4.0 g (40 mmol) of
.gamma.-valerolactone, 4.8 g (60 mmol) of pyridine, 300 g of
N-methyl-2-pyrrolidone (hereinafter referred to as NMP) and 20 g of
toluene were added, heated at 180.degree. C. for 1 hour and then
cooled to about room temperature, and subsequently 29.42 g (100
mmol) of 3,4,3',4'-biphenyl tetracarboxylic dianhydride, 102.65 g
(250 mmol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 200 g of
NMP and 40 g of toluene were added, mixed at room temperature for 1
hour and then heated at 180.degree. C. for 2 hours to obtain a
block copolymerized polyimide with a solid content of 38%. In this
block copolymerized polyimide, general formula (1): general formula
(2)=1:1, number average molecular weight: 50000, weight average
molecular weight: 100000. Also, the weight average molecular weight
of a block of imide oligomers of a structural unit represented by
the general formula (1) was 6000. This block copolymerized
polyimide resin solution was diluted with NMP into a block
copolymerized polyimide resin solution with a solid content of 15%
to obtain a block copolymerized polyimide (a3).
Comparative Synthesis Example 1
[0086] To a 2 L three neck flask having a reflux cooler equipped
with a ball cooling tube mounted on a trap with an anchor shaped
stirring stick, a nitrogen introducing tube and a stopcock of
stainless steel, 164 g (400 mmol) of ethylene glycol bistrimerytate
dianhydride, 124 g (400 mmol) of
4,4'-diamino-3,3',5,5'-tetraethyldiphenylmethane, 4.0 g (40 mmol)
of .gamma.-valerolactone, 4.8 g (60 mmol) of pyridine, 300 g of NMP
and 20 g of toluene were added, and heated at 180.degree. C. for 3
hours to obtain a polyimide resin solution. In this polyimide
resin, number average molecular weight: 31000, weight average
molecular weight: 78000. This polyimide resin solution (a) was
further diluted with NMP into a polyimide resin solution with a
solid content of 15% to obtain a comparative polyimide (e1).
Comparative Synthesis Example 2
[0087] To a 2 L three neck flask having a reflux cooler equipped
with a ball cooling tube mounted on a trap with an anchor shaped
stirring stick, a nitrogen introducing tube and a stopcock of
stainless steel, 147.1 g (500 mmol) of 3,4,3',4'-biphenyl
tetracarboxylic dianhydride, 73.08 g (250 mmol) of
1,3-bis(3-aminophenoxy)benzene, 102.65 g (250 mmol) of
2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4.0 g (40 mmol) of
.gamma.-valerolactone, 4.8 g (60 mmol) of pyridine, 500 g of
N-methyl-2-pyrolidone and 60 g of toluene were added, mixed at room
temperature for 1 hour, and heated at 180.degree. C. for 3 hours to
obtain a random copolymerized polyimide with a solid content of
38%. In this random copolymerized polyimide, general formula (1):
general formula (2)=1:1, number average molecular weight: 50000,
weight average molecular weight: 100000. This random copolymerized
polyimide resin solution was diluted with NMP into a random
copolymerized polyimide resin solution with a solid content of 15%
to obtain a random copolymerized polyimide (e2).
Example 1
[0088] The block copolymerized polyimide resin, (a1) solution
obtained in Synthesis Example 1 was further diluted with NMP into a
block copolymerized polyimide resin solution with a solid content
of 10%. The resulting resin solution was coated on a roughened
surface of an electrolytic copper foil with a thickness of 12 .mu.m
(FWG-WS foil made by Furukawa Electric, Rz=2.0 .mu.m, lightness
value 20, 3400 to 3800 minute projections with a height of 2 to 3
.mu.m are located in an area of 100 .mu.m.times.100 .mu.m on a
roughened surface, 12 to 17 minute projections are substantially
evenly located within a range of the observation cross sectional
surface of 25 .mu.m, the minute projection has a plurality of bored
portions on the lateral thereof as shown in FIG. 3) using a reverse
roll coater under the drying condition of at 120.degree. C. for 3
minutes and at 180.degree. C. for 3 minutes to prepare a resin
composite electrolytic copper foil with a resin thickness of 2
.mu.m. On the other hand, 400 g of 2,2-bis(4-cyanatophenyl)propane
was molten at 150.degree. C. and reacted for 4 hours while stirred,
this was dissolved in methyl ethyl ketone, and 600 g of brominated
bisphenol A type epoxy resin (Epiclon 1123P, made by DIC) and 0.1
part of zinc octoate were further added to prepare a varnish. This
varnish was impregnated in a glass woven cloth base material with a
thickness of 100 .mu.m and dried at 150.degree. C. for 6 minutes to
prepare a B-stage resin composition layer (prepreg) with a resin
content of 45%, a thickness of 105 .mu.m and a gelation time (at
170.degree. C.) of 120 seconds. A copper clad laminate with a
thickness of 0.4 mm was prepared by arranging the above resin
composition layer surface of the resin composite electrolytic
copper foil opposing on the upper and the lower surfaces of four of
these prepregs superimposed, and laminate molding at a temperature
of 220.degree. C., a pressure of 40 kgf/cm.sup.2 and a degree of
vacuum of not more than 30 mmHg for 1 hour.
[0089] Regarding the copper clad laminate prepared, the copper foil
was entirely removed with a hydrogen peroxide/sulfuric acid
solution, and then desmear treatment was conducted in swelling
treatment (mixing 400 ml of OPC-B103 PreEtch of Okuno Chemical
Industries and sodium hydroxide 13 g/l aqueous solution as a
reagent, immersing under a temperature of 65.degree. C. for 5
minutes, then washing with water for 1 minute), roughening
treatment (mixing 100 ml of OPC-1200 EpoEtch of Okuno Chemical
Industries and potassium permanganese 45 g/l aqueous solution,
immersing under a temperature of 80.degree. C. for 8 minutes, then
washing with water for 1 minute) and neutralizing treatment
(immersing in OPC-B303 neutralizing agent of Okuno Chemical
Industries 200 ml/l aqueous solution under a temperature of
45.degree. C. for 5 minutes, then washing with water for 1 minute)
processes. Moreover, a copper layer with a thickness of 1 .mu.m was
formed with an electroless plating solution (ATS AddCopper CT, made
by Okuno Chemical Industries) and heated in a furnace at
130.degree. C. for 2 hours, and electrolytic copper plating at 1.5
ampere/dm.sup.2 for 70 minutes was conducted with a copper sulfate
plating solution to prepare a laminate having a copper layer with a
thickness of 20 .mu.m formed. The evaluation result is shown in
Table 1.
Example 2, 3
[0090] Laminates having a copper layer with a thickness of 20 .mu.m
formed were prepared similarly as Example 1, except that the block
copolymerized polyimide resins (a2, a3) obtained in Synthesis
Examples 2 and 3 were used instead of the block copolymerized
polyimide resin (a1) obtained in Synthesis Example 1. The
evaluation result is shown in Table 1.
Example 4
[0091] A laminate having a copper layer with a thickness of 20
.mu.m formed was prepared similarly as Example 1, except that a
copper foil (HLPLCN foil made by Nippon Mining & Metal, Rz=1.5
.mu.m, lightness value 22, 3600 to 4000 minute projections with a
height of 2 to 3 .mu.m are located in an area of 100
.mu.m.times.100 .mu.m on a roughened surface, 14 to 20 minute
projections are substantially evenly located within a range of the
observation cross sectional surface of 25 .mu.m, the minute
projection has a plurality of bored portions on the lateral thereof
as shown in FIG. 2) was used instead of the electrolytic copper
foil (FWG-WS foil). The evaluation result is shown in Table 1.
Example 5
[0092] The block copolymerized polyimide resin (a1) solution
obtained in Synthesis Example 1 was further diluted with NMP into a
block copolymerized polyimide resin solution with a solid content
of 10%. To 1,000 g of this solution, 100 g of
2,2-bis[4-(4-maleimidephenoxy)phenyl]propane (BMI-80, KI Chemical
Industry) and 100 g of NMP were melt mixed at 60.degree. C. for 20
minutes to prepare a resin solution. The resulting resin solution
was coated on a roughened surface of an electrolytic copper foil
with a thickness of 12 .mu.m (FWG-WS foil made by Furukawa
Electric, Rz=2.0 .mu.m, lightness value 20, 3400 to 3800 minute
projections with a height of 2 to 3 .mu.m are located in an area of
100 .mu.m.times.100 .mu.m on a roughened surface, 12 to 17 minute
projections are substantially evenly located within a range of the
observation cross sectional surface of 25 .mu.m, the minute
projection has a plurality of bored portions on the lateral thereof
as shown in FIG. 3) using a reverse roll coater under the drying
condition of at 120.degree. C. for 3 minutes and at 180.degree. C.
for 3 minutes to prepare a resin composite electrolytic copper foil
with a resin thickness of 2 .mu.m. On the other hand, 400 g of
2,2-bis(4-cyanatophenyl)propane was molten at 150.degree. C. and
reacted for 4 hours while stirred, this was dissolved in methyl
ethyl ketone, and 600 g of brominated bisphenol A type epoxy resin
(Epiclon 1123P, made by DIC) and 0.1 part of zinc octoate were
further added to prepare a varnish. This varnish was impregnated in
a glass woven cloth base material with a thickness of 100 .mu.m and
dried at 150.degree. C. for 6 minutes to prepare a B-stage resin
composition layer (prepreg) with a resin content of 45%, a
thickness of 105 .mu.m and a gelation time (at 170.degree. C.) of
120 seconds. A copper clad laminate with a thickness of 0.4 mm was
prepared by arranging the above resin composition layer surface of
the resin composite electrolytic copper foil opposing on the upper
and the lower surfaces of four of these prepregs superimposed, and
laminate molding at a temperature of 220.degree. C., a pressure of
40 kgf/cm.sup.2 and a degree of vacuum of not more than 30 mmHg for
1 hour.
[0093] Regarding the copper clad laminate prepared, the copper foil
was entirely removed with a hydrogen peroxide/sulfuric acid
solution, and then desmear treatment was conducted in swelling
treatment (mixing 400 ml of OPC-B103 Preach of Okuno Chemical
Industries and sodium hydroxide 13 g/l aqueous solution as a
reagent, immersing under a temperature of 65.degree. C. for 5
minutes, then washing with water for 1 minute), roughening
treatment (mixing 100 ml of OPC-1200 EpoEtch of Okuno Chemical
Industries and potassium permanganese 45 g/l aqueous solution,
immersing under a temperature of 80.degree. C. for 8 minutes, then
washing with water for 1 minute) and neutralizing treatment
(immersing in OPC-B303 neutralizing agent of Okuno Chemical
Industries 200 ml/l aqueous solution under a temperature of
45.degree. C. for 5 minutes, then washing with water for 1 minute)
processes. Moreover, a copper layer with a thickness of 1 .mu.m was
formed with an electroless plating solution (ATS AddCopper CT, made
by Okuno Chemical Industries) and heated in a furnace at
130.degree. C. for 2 hours, and electrolytic copper plating at 1.5
ampere/dm.sup.2 for 70 minutes was conducted with a copper sulfate
plating solution to prepare a laminate having a copper layer with a
thickness of 20 .mu.m formed. The evaluation result is shown in
Table 2.
Example 6, 7
[0094] Laminates having a copper layer with a thickness of 20 .mu.m
formed were prepared similarly as Example 5, except that the block
copolymerized polyimide resins (a2, a3) obtained in Synthesis
Examples 2 and 3 were used. The evaluation result is shown in Table
2.
Example 8
[0095] A laminate having a copper layer with a thickness of 20
.mu.m formed was prepared similarly as Example 5, except that
bis(4-maleimidephenyl)methane (BMI, KI Chemical Industry) as a
maleimide compound was used. The evaluation result is shown in
Table 2.
Example 9
[0096] A laminate having a copper layer with a thickness of 20
.mu.m formed was prepared similarly as Example 5, except that a
copper foil (HLPLCN foil made by Nippon Mining & Metal, Rz=1.5
.mu.m, lightness value 22, 3600 to 4000 minute projections with a
height of 2 to 3 .mu.m are located in an area of 100
.mu.m.times.100 .mu.m on a roughened surface, 14 to 20 minute
projections are substantially evenly located within a range of the
observation cross sectional surface of 25 .mu.m, the minute
projection has a plurality of bored portions on the lateral thereof
as shown in FIG. 2) was used instead of the electrolytic copper
foil (FWG-WS foil). The evaluation result is shown in Table 2.
Example 10
[0097] The block copolymerized polyimide resin (a1) solution
obtained in Synthesis Example 1 was further diluted with NMP into a
block copolymerized polyimide resin solution with a solid content
of 10%. To 1,000 g of this solution, 70 parts of boehmite with an
average particle size of 0.6 .mu.m (product name: C06 made by
Taimei Chemicals) as the inorganic filler (b) was added, and
stirred with a homomixer for 1 hour to obtain a varnish of block
copolymerized polyimide containing an inorganic filler. The content
ratio by volume of the inorganic filler in the solid content of
this varnish was 23%. This varnish was applied to a roughened
surface of an electrolytic copper foil with a thickness of 12 .mu.m
(FWG-WS foil made by Furukawa Electric, Rz=2.0 .mu.m, lightness
value 20, 3400 to 3800 minute projections with a height of 2 to 3
.mu.m are located in an area of 100 .mu.m.times.100 .mu.m on a
roughened surface, 12 to 17 minute projections are substantially
evenly located within a range of the observation cross sectional
surface of 25 .mu.m, the minute projection has a plurality of bored
portions on the lateral thereof as shown in FIG. 3) using a reverse
roll coater, and dried under a nitrogen atmosphere at 120.degree.
C. for 3 minutes and at 170.degree. C. for 3 minutes to prepare a
resin composite copper foil. On the other hand, 400 g of
2,2-bis(4-cyanatophenyl)propane was molten at 150.degree. C. and
reacted for 4 hours while stirred, this was dissolved in methyl
ethyl ketone, and 600 g of brominated bisphenol A type epoxy resin
(Epiclon 1123P, made by DIC) and 0.1 part of zinc octoate were
further added to prepare a varnish. This varnish was impregnated in
a glass woven cloth base material with a thickness of 100 .mu.m and
dried at 150.degree. C. for 6 minutes to prepare a B-stage resin
composition layer (prepreg) with a resin content of 45%, a
thickness of 105 .mu.m and a gelation time (at 170.degree. C.) of
120 seconds. A copper clad laminate with a thickness of 0.4 mm was
prepared by arranging the above resin composition layer surface of
the resin composite electrolytic copper foil opposing on the upper
and the lower surfaces of four of these prepregs superimposed, and
laminate molding at a temperature of 220.degree. C., a pressure of
40 kgf/cm.sup.2 and a degree of vacuum of not more than 30 mmHg for
1 hour.
[0098] Regarding the copper clad laminate prepared, the copper foil
was entirely removed with a hydrogen peroxide/sulfuric acid
solution, and then Besmear treatment was conducted in swelling
treatment (mixing 400 ml of OPC-B103 PreEtch of Okuno Chemical
Industries and sodium hydroxide 13 g/l aqueous solution as a
reagent, immersing under a temperature of 65.degree. C. for 5
minutes, then washing with water for 1 minute), roughening
treatment (mixing 100 ml of OPC-1200 EpoEtch of Okuno Chemical
Industries and potassium permanganese 45 g/l aqueous solution,
immersing under a temperature of 80.degree. C. for 8 minutes, then
washing with water for 1 minute) and neutralizing treatment
(immersing in OPC-B303 neutralizing agent of Okuno Chemical
Industries 200 ml/l aqueous solution under a temperature of
45.degree. C. for 5 minutes, then washing with water for 1 minute)
processes. Moreover, a copper layer with a thickness of 1 .mu.m was
formed with an electroless plating solution (ATS AddCopper CT, made
by Okuno Chemical Industries) and heated in a furnace at
130.degree. C. for 2 hours, and electrolytic copper plating at 1.5
ampere/dm.sup.2 for 70 minutes was conducted with a copper sulfate
plating solution to prepare a laminate having a copper layer with a
thickness of 20 .mu.m formed. The evaluation result is shown in
Table 3.
Example 11
[0099] The block copolymerized polyimide resin (a1) solution
obtained in Synthesis Example 1 was further diluted with NMP into a
block copolymerized polyimide resin solution with a solid content
of 10%. To 1,000 g of this solution, 100 g of
2,2-bis[4-(4-maleimidephenoxy)phenyl]propane (BMI-80, KI Chemical
Industry) and 100 g of NMP were melt mixed at 60.degree. C. for 20
minutes to prepare a resin solution. To the resulting resin
solution, 140 parts of boehmite with an average particle size of
0.6 .mu.m (product name: C06 made by Taimei Chemicals) as the
inorganic filler (b) was further added, and stirred with a
homomixer for 1 hour to obtain a varnish of block copolymerized
polyimide containing an inorganic filler. The content ratio by
volume of the inorganic filler in the solid content of this varnish
was 20%. This varnish was coated on a roughened surface of an
electrolytic copper foil with a thickness of 12 .mu.m (FWG-WS foil
made by Furukawa Electric, Rz=2.0 .mu.m, lightness value 20, 3400
to 3800 minute projections with a height of 2 to 3 .mu.m are
located in an area of 100 .mu.m.times.100 .mu.m on a roughened
surface, 12 to 17 minute projections are substantially evenly
located within a range of the observation cross sectional surface
of 25 .mu.m, the minute projection has a plurality of bored
portions on the lateral thereof as shown in FIG. 3) using a reverse
roll coater, under the drying condition of at 120.degree. C. for 3
minutes and at 180.degree. C. for 3 minutes to prepare a resin
composite electrolytic copper foil with a resin thickness of 2
.mu.m. On the other hand, 400 g of 2,2-bis(4-cyanatophenyl)propane
was molten at 150.degree. C. and reacted for 4 hours while stirred,
this was dissolved in methyl ethyl ketone, and 600 g of brominated
bisphenol A type epoxy resin (Epiclon 1123P, made by DIC) and 0.1
part of zinc octoate were further added to prepare a varnish. This
varnish was impregnated in a glass woven cloth base material with a
thickness of 100 .mu.m and dried at 150.degree. C. for 6 minutes to
prepare a B-stage resin composition layer (prepreg) with a resin
content of 45%, a thickness of 105 .mu.m and a gelation time (at
170.degree. C.) of 120 seconds. A copper clad laminate with a
thickness of 0.4 mm was prepared by arranging the above resin
composition layer surface of the resin composite electrolytic
copper foil opposing on the upper and the lower surfaces of four of
these prepregs superimposed, and laminate molding at a temperature
of 220.degree. C., a pressure of 40 kgf/cm.sup.2 and a degree of
vacuum of not more than 30 mmHg for 1 hour.
[0100] Regarding the copper clad laminate prepared, the copper foil
was entirely removed with a hydrogen peroxide/sulfuric acid
solution, and then desmear treatment was conducted in swelling
treatment (mixing 400 ml of OPC-B103 PreEtch of Okuno Chemical
Industries and sodium hydroxide 130 aqueous solution as a reagent,
immersing under a temperature of 65.degree. C. for 5 minutes, then
washing with water for 1 minute), roughening treatment (mixing 100
ml of OPC-1200 EpoEtch of Okuno Chemical Industries and potassium
permanganese 45 g/l aqueous solution, immersing under a temperature
of 80.degree. C. for 8 minutes, then washing with water for 1
minute) and neutralizing treatment (immersing in OPC-B303
neutralizing agent of Okuno Chemical Industries 200 ml/l aqueous
solution under a temperature of 45.degree. C. for 5 minutes, then
washing with water for 1 minute) processes. Moreover, a copper
layer with a thickness of 1 .mu.m was formed with an electroless
plating solution (ATS AddCopper CT, made by Okuno Chemical
Industries) and heated in a furnace at 130.degree. C. for 2 hours,
and electrolytic copper plating at 1.5 ampere/dm.sup.2 for 70
minutes was conducted with a copper sulfate plating solution to
prepare a laminate having a copper layer with a thickness of 20
.mu.m formed. The evaluation result is shown in Table 3.
Example 12, 13
[0101] Laminates having a copper layer with a thickness of 20 .mu.m
formed were prepared similarly as Example 11, except that the block
copolymerized polyimide resins (a2, a3) obtained in Synthesis
Examples 2 and 3 were used instead of the block copolymerized
polyimide resin (a1) obtained in Synthesis Example 1. The
evaluation result is shown in Table 3.
Example 14
[0102] A laminate having a copper layer with a thickness of 20
.mu.m formed was prepared similarly as Example 11, except that an
electrolytic copper foil (HLPLCN foil made by Nippon Mining &
Metal, Rz==1.5 .mu.m, lightness value 22, 3600 to 4000 minute
projections with a height of 2 to 3 .mu.m are located in an area of
100 .mu.m.times.100 .mu.m on a roughened surface, 14 to 20 minute
projections are substantially evenly located within a range of the
observation cross sectional surface of 25 .mu.m, the minute
projection has a plurality of bored portions on the lateral thereof
as shown in FIG. 2) was used instead of the electrolytic copper
foil (FWG-WS foil). The evaluation result is shown in Table 3.
[0103] In addition, conditions for each evaluation item are as
follows,
[0104] 1) Copper Foil (Plated Copper) Adhesion Strength
[0105] According to JIS 06481, adhesion strength is measured to
show the average value of three measurements.
[0106] 2) Heat Resistance Test (288.degree. C. Treatment)
[0107] According to IPC-TM-650 2.4.24, the time when swelling
occurred was measured with TMA2940 equipment of TA Instruments with
a load of 0.005N (5 g) at a temperature increased to 288.degree. C.
by a temperature increase rate of 10.degree. C./min and kept at
288.degree. C. from the time when the temperature reaches
288.degree. C. as the measurement start time. Additionally, in the
case when swelling occurs at a temperature below 288.degree. C., it
is stated as minute 0. The average value of three measurements is
shown.
[0108] Also, portions where swelling occurred were observed with a
500 powered microscope. The swollen portions are shown as the
following representations.
[0109] Swelling between copper and the resin composition (B) is
(X); Swelling between the resin composition (B) and the B-stage
resin composition layer (prepreg) is (Y);
[0110] Swelling between the B-stage resin composition layer
(prepreg) and the B-stage resin composition layer (prepreg) is
(Z).
[0111] 3) Heat Resistance Under Moisture Absorption
[0112] A copper foil of a 50 mm.times.50 mm sample was removed by
etching apart from half of one surface, treated with a pressure
cooker test equipment (PC-3 model made by Hirayama Manufacturing)
at 121.degree. C. and 2 atmospheres for a predetermined time, and
then floated for 60 seconds in a solder bath at 260.degree. C. to
visually observe the presence of abnormality in appearance change.
The evaluation criteria are as follows.
.smallcircle.: no abnormality x: occurrence of swelling,
peeling
[0113] 4) Molecular Weight Measurement
[0114] The number average molecular weight and the weight average
molecular weight were measured using gel permeation chromatography
(TOSOH HLC-8220 model equipment) in polystyrene conversion using
N-methyl-2-pyrrolidon as a developing solvent.
TABLE-US-00001 TABLE 1 Example 1 Example 2 Example 3 Example 4
Synthesis Example 1 100 100 (a-1) Synthesis Example 2 100 (a-2)
Synthesis Example 3 100 (a-3) Name of copper foil FWG-WS FWG-WS
FWG-WS HLPLCN Plated copper adhesion 1.23 1.18 1.08 1.11 strength
after desmear treatment (kgf/cm) Heat resistance (min) 11.3 10.9
10.4 9.8 Heat resistance evaluated X X X X swollen portion Heat
resistance under moisture absorption 1 hour treatment
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.largecircle..largecircle..largecircle. 3 hour treatment
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.largecircle..largecircle..largecircle. 5 hour treatment
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TABLE-US-00002 TABLE 2 Example 5 Example 6 Example 7 Example 8
Example 9 Synthesis Example 1 (a-1) 100 100 100 Synthesis Example 2
(a-2) 100 Synthesis Example 3 (a-3) 100 BMI80 100 100 100 100 BMI
100 Name of copper foil FWG-WS FWG-WS FWG-WS FWG-WS HLPLCN Plated
copper adhesion strength after 1.16 1.15 1.16 0.98 1.02 desmear
treatment (kgf/cm) Heat resistance (min) 27.6 25.3 24.8 15.0 25.7
Heat resistance evaluated swollen portion X X X X X Heat resistance
under moisture absorption 1 hour treatment
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.largecircle..largecircle..largecircle. 3 hour treatment
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.largecircle..largecircle..largecircle. 5 hour treatment
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TABLE-US-00003 TABLE 3 Example Example Example Example Example 10
11 12 13 14 Synthesis Example 1 (a-1) 100 100 100 Synthesis Example
2 (a-2) 100 Synthesis Example 3 (a-3) 100 BMI80 100 100 100 100 C06
70 140 140 140 140 Inorganic filler content by volume (%) 23.1 20.1
20.1 20.1 20.1 Name of copper foil FWG-WS FWG-WS FWG-WS FWG-WS
HLPLCN Plated copper adhesion strength after 0.89 0.81 0.82 0.81
0.79 desmear treatment (kgf/cm) Heat resistance (min) 43.9 50.8
53.6 49.2 44.8 Heat resistance evaluated swollen portion X X X X X
Heat resistance under moisture absorption 1 hour treatment
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.largecircle..largecircle..largecircle.
.largecircle..largecircle..largecircle. 3 hour treatment
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.largecircle..largecircle..largecircle. 5 hour treatment
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Comparative Example 1
[0115] The polyimide resin (e1) solution obtained in Comparative
Synthesis Example 1 was further diluted with NMP into a block
copolymerized polyimide resin solution with a solid content of 10%.
The resulting resin solution was coated on a roughened surface of
an electrolytic copper foil with a thickness of 12 .mu.m (GTS-MP,
made by Furukawa Electric, Rz=6.8 lightness value 36, 100 to 190
minute projections with a height of 5 to 7 .mu.m are located in an
area of 100 .mu.m.times.100 .mu.m on a roughened surface, 5 to 8
minute projections are substantially evenly located within a range
of the observation cross sectional surface of 25 .mu.m, the minute
projection formed on the above roughened surface of the
electrolytic copper foil has no bored portion on the lateral
thereof as shown in FIG. 4, the volume of pores with a pore
diameter of 100 to 1000 nm formed is considerably smaller than
Examples) using a reverse roll coater under the drying condition of
at 120.degree. C. for 3 minutes and at 180.degree. C. for 3 minutes
to prepare a resin composite electrolytic copper foil with a resin
thickness of 2 .mu.m. On the other hand, 400 g of
2,2-bis(4-cyanatophenyl)propane was molten at 150.degree. C. and
reacted for 4 hours while stirred, this was dissolved in methyl
ethyl ketone, and 600 g of brominated bisphenol A type epoxy resin
(Epiclon 1123P, made by DIC) and 0.1 part of zinc octoate were
further added to prepare a varnish. This varnish was impregnated in
a glass woven cloth base material with a thickness of 100 .mu.m and
dried at 150.degree. C. for 6 minutes to prepare a B-stage resin
composition layer (prepreg) with a resin content of 45%, a
thickness of 105 .mu.m and a gelation time (at 170.degree. C.) of
120 seconds. A copper clad laminate with a thickness of 0.4 mm was
prepared by arranging the above resin composition layer surface of
the resin composite electrolytic copper foil opposing on the upper
and the lower surfaces of four of these prepregs superimposed, and
laminate molding at a temperature of 220.degree. C., a pressure of
40 kgf/cm.sup.2 and a degree of vacuum of not more than 30 mmHg for
1 hour.
[0116] The copper foil of the copper clad laminate prepared was
entirely removed with a hydrogen peroxide/sulfuric acid solution,
and then desmear treatment was concluded with an alkaline oxidation
agent of permanganate. Moreover, a copper layer with a thickness of
1 .mu.m was formed with an electroless plating solution (ATS
AddCopper CT, made by Okuno Chemical Industries) and heated in a
furnace at 130.degree. C. for 2 hours, and then electrolytic copper
plating at 1.5 ampere/dm.sup.2 for 70 minutes was conducted with a
copper sulfate plating solution to prepare a laminate having a
copper layer with a thickness of 20 .mu.m formed. The evaluation
result is shown in Table 4.
Comparative Example 2
[0117] A laminate having a copper layer with a thickness of 20
.mu.m formed was prepared similarly as Comparative Example 1,
except the random copolymerized polyimide (e2) obtained in
Comparative Synthesis Examples 2. The evaluation result is shown in
Table 4.
Comparative Example 3
[0118] A laminate having a copper layer with a thickness of 20
.mu.m formed was prepared similarly as Comparative Example 2,
except that the electrolytic copper foil with a thickness of 12
.mu.m (FWG-WS foil made by Furukawa Electric, Rz=2.0 .mu.m,
lightness value 20, 3400 to 3800 minute projections with a height
of 2 to 3 .mu.m are located in an area of 100 .mu.m.times.100 .mu.m
on a roughened surface, 12 to 17 minute projections are
substantially evenly located within a range of the observation
cross sectional surface of 25 .mu.m, the minute projection has a
plurality of bored portions on the lateral thereof as shown in FIG.
3) was used. The evaluation result is shown in Table 4.
Comparative Example 4
[0119] The polyimide resin (e1) solution obtained in Comparative
Synthesis Example 1 was further diluted with NMP into a polyimide
resin solution with a solid content of 10%. To 1,000 g of this
solution, 100 g of bis(4-maleimidephenyl)methane (BMI, KI Chemical
Industry) and 100 g of NMP were melt mixed at 60.degree. C. for 20
minutes to prepare a resin solution. The resulting resin solution
was coated on a roughened surface of an electrolytic copper foil
with a thickness of 12 .mu.m (GTS-MP, made by Furukawa Electric,
Rz=6.8 .mu.m, lightness value 36, 100 to 190 minute projections
with a height of 5 to 7 .mu.m are located in an area of 100
.mu.m.times.100 .mu.m on a roughened surface, 5 to 8 minute
projections are substantially evenly located within a range of the
observation cross sectional surface of 25 .mu.m, the minute
projection formed on the above roughened surface of the
electrolytic copper foil has no bored portion on the lateral
thereof as shown in FIG. 4, the volume of pores with a pore
diameter of 100 to 1000 nm formed is considerably smaller than
Examples) using a reverse roll coater under the drying condition of
at 120.degree. C. for 3 minutes and at 180.degree. C. for 3 minutes
to prepare a resin composite electrolytic copper foil with a resin
thickness of 2 .mu.m. On the other hand, 400 g of
2,2-bis(4-cyanatophenyl)propane was molten at 150.degree. C. and
reacted for 4 hours while stirred, this was dissolved in methyl
ethyl ketone, and 600 g of brominated bisphenol A type epoxy resin
(Epiclon 1123P, made by DIC) and 0.1 part of zinc octoate were
further added to prepare a varnish. This varnish was impregnated in
a glass woven cloth base material with a thickness of 100 .mu.m and
dried at 150.degree. C. for 6 minutes to prepare a B-stage resin
composition layer (prepreg) with a resin content of 45%, a
thickness of 105 .mu.m and a gelation time (at 170.degree. C.) of
120 seconds. A copper clad laminate with a thickness of 0.4 mm was
prepared by arranging the above resin composition layer surface of
the resin composite electrolytic copper foil opposing on the upper
and the lower surfaces of four of these prepregs superimposed, and
laminate molding at a temperature of 220.degree. C., a pressure of
40 kgf/cm.sup.2 and a degree of vacuum of not more than 30 mmHg for
1 hour.
[0120] Regarding the copper clad laminate prepared, the copper foil
was entirely removed with a hydrogen peroxide/sulfuric acid
solution, and then desmear treatment was conducted in swelling
treatment (mixing 400 ml of OPC-B103 PreEtch of Okuno Chemical
Industries and sodium hydroxide 13 g/l aqueous solution as a
reagent, immersing under a temperature of 65.degree. C. for 5
minutes, then washing with water for 1 minute), roughening
treatment (mixing 100 ml of OPC-1200 EpoEtch of Okuno Chemical
Industries and potassium permanganese 45 g/l aqueous solution,
immersing under a temperature of 80.degree. C. for 8 minutes, then
washing with water for 1 minute) and neutralizing treatment
(immersing in OPC-B303 neutralizing agent of Okuno Chemical
Industries 200 ml/l aqueous solution under a temperature of
45.degree. C. for 5 minutes, then washing with water for 1 minute)
processes. Moreover, a copper layer with a thickness of 1 .mu.m was
formed with an electroless plating solution (ATS AddCopper CT, made
by Okuno Chemical Industries) and heated in a furnace at
130.degree. C. for 2 hours, and electrolytic copper plating at 1.5
ampere/dm.sup.2 for 70 minutes was conducted with a copper sulfate
plating solution to prepare a laminate having a copper layer with a
thickness of 20 .mu.m formed. The evaluation result is shown in
Table 5.
Comparative Example 5
[0121] A laminate having a copper layer with a thickness of 20
.mu.m formed was prepared similarly as Comparative Example 4,
except the random copolymerized polyimide (e2) obtained in
Comparative Synthesis Examples 2. The evaluation result is shown in
Table 5.
Comparative Example 6
[0122] A laminate having a copper layer with a thickness of 20
.mu.m formed was prepared similarly as Comparative Example 5,
except 2,2-bis[4-(4-maleimidephenoxy)phenyl]propane (BMI-80, KI
Chemical Industry). The evaluation result is shown in Table 5.
Comparative Example 7
[0123] A laminate having a copper layer with a thickness of 20
.mu.m formed was prepared similarly as Comparative Example 6,
except that the electrolytic copper foil with a thickness of 12
.mu.m (FWG-WS foil made by Furukawa Electric, Rz=2.0 .mu.m,
lightness value 20, 3400 to 3800 minute projections with a height
of 2 to 3 .mu.m are located in an area of 100 .mu.m.times.100 .mu.m
on a roughened surface, 12 to 17 minute projections are
substantially evenly located within a range of the observation
cross sectional surface of 25 .mu.m, the minute projection has a
plurality of bored portions on the lateral thereof as shown in FIG.
3) was used. The evaluation result is shown in Table 5.
Comparative Example 8
[0124] The polyimide resin (e1) solution obtained in Comparative
Synthesis Example 1 was further diluted with NMP into a polyimide
resin solution with a solid content of 10%. To 1,000 g of this
solution, 70 parts of boehmite with an average particle size of 0.6
.mu.m (product name: C06 made by Taimei Chemicals) as the inorganic
filler (b) was added, and stirred with a homomixer for 1 hour to
obtain a varnish of polyimide containing an inorganic filler. The
content ratio by volume of the inorganic filler in the solid
content of this varnish was 23%. This varnish was coated on a
roughened surface of an electrolytic copper foil with a thickness
of 12 .mu.m (GTS-MP, made by Furukawa Electric, Rz=6.8 .mu.m,
lightness value 36, 100 to 190 minute projections with a height of
5 to 7 .mu.m are located in an area of 100 .mu.m.times.100 .mu.m on
a roughened surface, 5 to 8 minute projections are substantially
evenly located within a range of the observation cross sectional
surface of 25 .mu.m, the minute projection formed on the above
roughened surface of the electrolytic copper foil has no bored
portion on the lateral thereof as shown in FIG. 4, the volume of
pores with a pore diameter of 100 to 1000 nm formed is considerably
smaller than Examples) using a reverse roll coater under the drying
condition of at 120.degree. C. for 3 minutes and at 180.degree. C.
for 3 minutes to prepare a resin composite electrolytic copper foil
with a resin thickness of 2 .mu.m. On the other hand, 400 g of
2,2-bis(4-cyanatophenyl)propane was molten at 150.degree. C. and
reacted for 4 hours while stirred, this was dissolved in methyl
ethyl ketone, and 600 g of brominated bisphenol A type epoxy resin
(Epiclon 1123P, made by DIC) and 0.1 part of zinc octoate were
further added to prepare a varnish. This varnish was impregnated in
a glass woven cloth base material with a thickness of 100 .mu.m and
dried at 150.degree. C. for 6 minutes to prepare a B-stage resin
composition layer (prepreg) with a resin content of 45%, a
thickness of 105 .mu.m and a gelation time (at 170.degree. C.) of
120 seconds. A copper clad laminate with a thickness of 0.4 mm was
prepared by arranging the above resin composition layer surface of
the resin composite electrolytic copper foil opposing on the upper
and the lower surfaces of four of these prepregs superimposed, and
laminate molding at a temperature of 220.degree. C., a pressure of
40 kgf/cm.sup.2 and a degree of vacuum of not more than 30 mmHg for
1 hour.
[0125] Regarding the copper clad laminate prepared, the copper foil
was entirely removed with a hydrogen peroxide/sulfuric acid
solution, and then desmear treatment was conducted in swelling
treatment (mixing 400 ml of OPC-B103 PreEtch of Okuno Chemical
Industries and sodium hydroxide 13 g/l aqueous solution as a
reagent, immersing under a temperature of 65.degree. C. for 5
minutes, then washing with water for 1 minute), roughening
treatment (mixing 100 ml of OPC-1200 EpoEtch of Okuno Chemical
Industries and potassium permanganese 45 g/l aqueous solution,
immersing under a temperature of 80.degree. C. for 8 minutes, then
washing with water for 1 minute) and neutralizing treatment
(immersing in OPC-B303 neutralizing agent of Okuno Chemical
Industries 200 ml/l aqueous solution under a temperature of
45.degree. C. for 5 minutes, then washing with water for 1 minute)
processes. Moreover, a copper layer with a thickness of 1 .mu.m was
formed with an electroless plating solution (ATS AddCopper CT, made
by Okuno Chemical Industries) and heated in a furnace at
130.degree. C. for 2 hours, and electrolytic copper plating at 1.5
ampere/dm.sup.2 for 70 minutes was conducted with a copper sulfate
plating solution to prepare a laminate having a copper layer with a
thickness of 20 pan formed. The evaluation result is shown in Table
6.
Comparative Example 9
[0126] A laminate having a copper layer with a thickness of 20
.mu.m formed was prepared similarly as Comparative Example 8,
except the random copolymerized polyimide (e2) obtained in
Comparative Synthesis Examples 2. The evaluation result is shown in
Table 6.
Comparative Example 10
[0127] The block copolymerized polyimide resin (a1) solution
obtained in Comparative Example 1 was further diluted with NMP into
a block copolymerized polyimide resin solution with a solid content
of 10%. To 1,000 g of this solution, 100 g of
2,2-bis[4(4-maleimidephenoxy)phenyl]propane (BMI-80, KI Chemical
Industry) and 100 g of NMP were melt mixed at 60.degree. C. for 20
minutes to prepare a resin solution. To the resulting resin
solution, 140 parts of boehmite with an average particle size of
0.6 .mu.m (product name: C06 made by Taimei Chemicals) as the
inorganic filler (b) was further added, and stirred with a
homomixer for 1 hour to obtain a varnish of block copolymerized
polyimide containing an inorganic filler. The content ratio by
volume of the inorganic filler in the solid content of this varnish
was 20%. This varnish was coated on a roughened surface of an
electrolytic copper foil with a thickness of 12 .mu.m (GTS-MP, made
by Furukawa Electric, Rz=6.8 .mu.m, lightness value 36, 100 to 190
minute projections with a height of 5 to 7 .mu.m are located in an
area of 100 .mu.m.times.100 .mu.m on a roughened surface, 5 to 8
minute projections are substantially evenly located within a range
of the observation cross sectional surface of 25 .mu.m, the minute
projection formed on the above roughened surface of the
electrolytic copper foil has no bored portion on the lateral
thereof as shown in FIG. 4, the volume of pores with a pore
diameter of 100 to 1000 nm formed is considerably smaller than
Examples) using a reverse roll coater under the drying condition of
at 120.degree. C. for 3 minutes and at 180.degree. C. for 3 minutes
to prepare a resin composite electrolytic copper foil with a resin
thickness of 2 .mu.m. On the other hand, 400 g of
2,2-bis(4-cyanatophenyl)propane was molten at 150.degree. C. and
reacted for 4 hours while stirred, this was dissolved in methyl
ethyl ketone, and 600 g of brominated bisphenol A type epoxy resin
(Epiclon 1123P, made by DIC) and 0.1 part of zinc octoate were
further added to prepare a varnish. This varnish was impregnated in
a glass woven cloth base material with a thickness of 100 .mu.m and
dried at 150.degree. C. for 6 minutes to prepare a B-stage resin
composition layer (prepreg) with a resin content of 45%, a
thickness of 105 .mu.m and a gelation time (at 170.degree. C.) of
120 seconds. A copper clad laminate with a thickness of 0.4 mm was
prepared by arranging the above resin composition layer surface of
the resin composite electrolytic copper foil opposing on the upper
and the lower surfaces of four of these prepregs superimposed, and
laminate molding at a temperature of 220.degree. C., a pressure of
40 kgf/cm.sup.2 and a degree of vacuum of not more than 30 mmHg for
1 hour.
[0128] Regarding the copper clad laminate prepared, the copper foil
was entirely removed with a hydrogen peroxide/sulfuric acid
solution, and then desmear treatment was conducted in swelling
treatment (mixing 400 ml of OPC-B103 PreEtch of Okuno Chemical
Industries and sodium hydroxide 13 g/l aqueous solution as a
reagent, immersing under a temperature of 65.degree. C. for 5
minutes, then washing with water for 1 minute), roughening
treatment (mixing 100 ml of OPC-1200 EpoEtch of Okuno Chemical
Industries and potassium permanganese 45 g/l aqueous solution,
immersing under a temperature of 80.degree. C. for 8 minutes, then
washing with water for 1 minute) and neutralizing treatment
(immersing in OPC-B303 neutralizing agent of Okuno Chemical
Industries 200 ml/l aqueous solution under a temperature of
45.degree. C. for 5 minutes, then washing with water for 1 minute)
processes. Moreover, a copper layer with a thickness of 1 .mu.m was
formed with an electroless plating solution (ATS AddCopper CT, made
by Okuno Chemical Industries) and heated in a furnace at
130.degree. C. for 2 hours, and electrolytic copper plating at 1.5
ampere/dm.sup.2 for 70 minutes was conducted with a copper sulfate
plating solution to prepare a laminate having a copper layer with a
thickness of 20 .mu.m formed. The evaluation result is shown in
Table 6.
Comparative Example 11
[0129] A laminate having a copper layer with a thickness of 20
.mu.m formed was prepared similarly as Comparative Example 10,
except the random copolymerized polyimide (e2) obtained in
Comparative Synthesis Examples 2. The evaluation result is shown in
Table 6.
Comparative Example 12
[0130] A laminate having a copper layer with a thickness of 20
.mu.m formed was prepared similarly as Comparative Example 11,
except the electrolytic copper foil with a thickness of 12 .mu.m
(FWG-WS foil made by Furukawa Electric, Rz=2.0 .mu.m, lightness
value 20, 3400 to 3800 minute projections with a height of 2 to 3
.mu.m are located in an area of 100 .mu.m.times.100 .mu.m on a
roughened surface, 12 to 17 minute projections are substantially
evenly located within a range of the observation cross sectional
surface of 25 .mu.m, the minute projection has a plurality of bored
portions on the lateral thereof as shown in FIG. 3). The evaluation
result is shown in Table 6.
Comparative Example 13
[0131] The block copolymerized polyimide resin (a1) solution
obtained in Synthesis Example 1 was further diluted with NMP into a
block copolymerized polyimide resin solution with a solid content
of 10%. The resulting resin solution was coated on a roughened
surface of an electrolytic copper foil with a thickness of 12 .mu.m
(GTS-MP, made by Furukawa Electric, Rz=6.8 .mu.m, lightness value
36, 100 to 190 minute projections with a height of 5 to 7 .mu.m are
located in an area of 100 .mu.m.times.100 .mu.m on a roughened
surface, 5 to 8 minute projections are substantially evenly located
within a range of the observation cross sectional surface of 25
.mu.m, the minute projection formed on the above roughened surface
of the electrolytic copper foil has no bored portion on the lateral
thereof as shown in FIG. 4, the volume of pores with a pore
diameter of 100 to 1000 nm formed is considerably smaller than
Examples) using a reverse roll coater under the drying condition of
at 120.degree. C. for 3 minutes and at 180.degree. C. for 3 minutes
to prepare a resin composite electrolytic copper foil with a resin
thickness of 2 .mu.m. On the other hand, 400 g of
2,2-bis(4-cyanatophenyl)propane was molten at 150.degree. C. and
reacted for 4 hours while stirred, this was dissolved in methyl
ethyl ketone, and 600 g of brominated bisphenol A type epoxy resin
(Epiclon 1123P, made by DIC) and 0.1 part of zinc octoate were
further added to prepare a varnish. This varnish was impregnated in
a glass woven cloth base material with a thickness of 100 .mu.m and
dried at 150.degree. C. for 6 minutes to prepare a B-stage resin
composition layer (prepreg) with a resin content of 45%, a
thickness of 105 .mu.m and a gelation time (at 170.degree. C.) of
120 seconds. A copper clad laminate with a thickness of 0.4 mm was
prepared by arranging the above resin composition layer surface of
the resin composite electrolytic copper foil opposing on the upper
and the lower surfaces of four of these prepregs superimposed, and
laminate molding at a temperature of 220.degree. C., a pressure of
40 kgf/cm.sup.2 and a degree of vacuum of not more than 30 mmHg for
1 hour.
[0132] Regarding the copper clad laminate prepared, the copper foil
was entirely removed with a hydrogen peroxide/sulfuric acid
solution, and then desmear treatment was conducted in swelling
treatment (mixing 400 ml of OPC-B103 PreEtch of Okuno Chemical
Industries and sodium hydroxide 13 g/l aqueous solution as a
reagent, immersing under a temperature of 65.degree. C. for 5
minutes, then washing with water for 1 minute), roughening
treatment (mixing 100 ml of OPC-1200 EpoEtch of Okuno Chemical
Industries and potassium permanganese 45 g/l aqueous solution,
immersing under a temperature of 80.degree. C. for 8 minutes, then
washing with water for 1 minute) and neutralizing treatment
(immersing in OPC-B303 neutralizing agent of Okuno Chemical
Industries 200 ml/l aqueous solution under a temperature of
45.degree. C. for 5 minutes, then washing with water for 1 minute)
processes. Moreover, a copper layer with a thickness of 1 .mu.m was
formed with an electroless plating solution (ATS AddCopper CT, made
by Okuno Chemical Industries) and heated in a furnace at
130.degree. C. for 2 hours, and electrolytic copper plating at 1.5
ampere/dm.sup.2 for 70 minutes was conducted with a copper sulfate
plating solution to prepare a laminate having a copper layer with a
thickness of 20 .mu.m formed. The evaluation result is shown in
Table 7.
Comparative Example 14
[0133] The block copolymerized polyimide resin (a1) solution
obtained in Synthesis Example 1 was further diluted with NMP into a
block copolymerized polyimide resin solution with a solid content
of 10%. To 1,000 g of this solution, 100 g of
2,2-bis[4-(4-maleimidephenoxy)phenyl]propane (BMI-80, KI Chemical
Industry) and 100 g of NMP were melt mixed at 60.degree. C. for 20
minutes to prepare a resin solution. The resulting resin solution
was coated on a roughened surface of an electrolytic copper foil
with a thickness of 12 .mu.m (GTS-MP, made by Furukawa Electric,
Rz=6.8 .mu.m, lightness value 36, 100 to 190 minute projections
with a height of 5 to 7 .mu.m are located in an area of 100
.mu.m.times.100 .mu.m on a roughened surface, 5 to 8 minute
projections are substantially evenly located within a range of the
observation cross sectional surface of 25 .mu.m, the minute
projection formed on the above roughened surface of the
electrolytic copper foil has no bored portion on the lateral
thereof as shown in FIG. 4, the volume of pores with a pore
diameter of 100 to 1000 nm formed is considerably smaller than
Examples) using a reverse roll coater under the drying condition of
at 120.degree. C. for 3 minutes and at 180.degree. C. for 3 minutes
to prepare a resin composite electrolytic copper foil with a resin
thickness of 2 .mu.m. On the other hand, 400 g of
2,2-bis(4-cyanatophenyl)propane was molten at 150.degree. C. and
reacted for 4 hours while stirred, this was dissolved in methyl
ethyl ketone, and 600 g of brominated bisphenol A type epoxy resin
(Epiclon 1123P, made by DIC) and 0.1 part of zinc octoate were
further added to prepare a varnish. This varnish was impregnated in
a glass woven cloth base material with a thickness of 100 .mu.m and
dried at 150.degree. C. for 6 minutes to prepare a B-stage resin
composition layer (prepreg) with a resin content of 45%, a
thickness of 105 .mu.m and a gelation time (at 170.degree. C.) of
120 seconds. A copper clad laminate with a thickness of 0.4 mm was
prepared by arranging the above resin composition layer surface of
the resin composite electrolytic copper foil opposing on the upper
and the lower surfaces of four of these prepregs superimposed, and
laminate molding at a temperature of 220.degree. C., a pressure of
40 kgf/cm.sup.2 and a degree of vacuum of not more than 30 mmHg for
1 hour.
[0134] Regarding the copper clad laminate prepared, the copper foil
was entirely removed with a hydrogen peroxide/sulfuric acid
solution, and then desmear treatment was conducted in swelling
treatment (mixing 400 ml of OPC-B103 PreEtch of Okuno Chemical
Industries and sodium hydroxide 13 g/l aqueous solution as a
reagent, immersing under a temperature of 65.degree. C. for 5
minutes, then washing with water for 1 minute), roughening
treatment (mixing 100 ml of OPC-1200 EpoEtch of Okuno Chemical
Industries and potassium permanganese 45 g/l aqueous solution,
immersing under a temperature of 80.degree. C. for 8 minutes, then
washing with water for 1 minute) and neutralizing treatment
(immersing in OPC-B303 neutralizing agent of Okuno Chemical
Industries 200 ml/l aqueous solution under a temperature of
45.degree. C. for 5 minutes, then washing with water for 1 minute)
processes. Moreover, a copper layer with a thickness of 1 .mu.m was
formed with an electroless plating solution (ATS AddCopper CT, made
by Okuno Chemical Industries) and heated in a furnace at
130.degree. C. for 2 hours, and electrolytic copper plating at 1.5
ampere/dm.sup.2 for 70 minutes was conducted with a copper sulfate
plating solution to prepare a laminate having a copper layer with a
thickness of 20 .mu.m formed. The evaluation result is shown in
Table 7.
Comparative Example 15
[0135] The block copolymerized polyimide resin (a1) solution
obtained in Synthesis Example 1 was further diluted with NMP into a
block copolymerized polyimide resin solution with a solid content
of 10%. To 1,000 g of this solution, 100 g of
2,2-bis[4-(4-maleimidephenoxy)phenyl]propane (BMI-80, KI Chemical
Industry) and 100 g of NMP were melt mixed at 60.degree. C. for 20
minutes to prepare a resin solution. To the resulting resin
solution, 140 parts of boehmite with an average particle size of
0.6 .mu.m (product name: C06 made by Taimei Chemicals) as the
inorganic filler (b) was further added, and stirred with a
homomixer for 1 hour to obtain a varnish of block copolymerized
polyimide containing an inorganic filler. The content ratio by
volume of the inorganic filler in the solid content of this varnish
was 20%. This varnish was coated on a roughened surface of an
electrolytic copper foil with a thickness of 12 .mu.m (GTS-MP, made
by Furukawa Electric, Rz=6.8 .mu.m, lightness value 36, 100 to 190
minute projections with a height of 5 to 7 .mu.m are located in an
area of 100 .mu.m.times.100 .mu.m on a roughened surface, 5 to 8
minute projections are substantially evenly located within a range
of the observation cross sectional surface of 25 .mu.m, the minute
projection formed on the above roughened surface of the
electrolytic copper foil has no bored portion on the lateral
thereof as shown in FIG. 4, the volume of pores with a pore
diameter of 100 to 1000 nm formed is considerably smaller than
Examples) using a reverse roll coater under the drying condition of
at 120.degree. C. for 3 minutes and at 180.degree. C. for 3 minutes
to prepare a resin composite electrolytic copper foil with a resin
thickness of 2 .mu.m. On the other hand, 400 g of
2,2-bis(4-cyanatophenyl)propane was molten at 150.degree. C. and
reacted for 4 hours while stirred, this was dissolved in methyl
ethyl ketone, and 600 g of brominated bisphenol A type epoxy resin
(Epiclon 1123P, made by DIC) and 0.1 part of zinc octoate were
further added to prepare a varnish. This varnish was impregnated in
a glass woven cloth base material with a thickness of 100 .mu.m and
dried at 150.degree. C. for 6 minutes to prepare a B-stage resin
composition layer (prepreg) with a resin content of 45%, a
thickness of 105 .mu.m and a gelation time (at 170.degree. C.) of
120 seconds. A copper clad laminate with a thickness of 0.4 mm was
prepared by arranging the above resin composition layer surface of
the resin composite electrolytic copper foil opposing on the upper
and the lower surfaces of four of these prepregs superimposed, and
laminate molding at a temperature of 220.degree. C., a pressure of
40 kgf/cm.sup.2 and a degree of vacuum of not more than 30 mmHg for
1 hour.
[0136] Regarding the copper clad laminate prepared, the copper foil
was entirely removed with a hydrogen peroxide/sulfuric acid
solution, and then desmear treatment was conducted in swelling
treatment (mixing 400 ml of OPC-B103 PreEtch of Okuno Chemical
Industries and sodium hydroxide 13 g/l aqueous solution as a
reagent, immersing under a temperature of 65.degree. C. for 0.5
minutes, then washing with water for 1 minute), roughening
treatment (mixing 100 ml of OPC-1200 EpoEtch of Okuno Chemical
Industries and potassium permanganese 45 g/l aqueous solution,
immersing under a temperature of 80.degree. C. for 8 minutes, then
washing with water for 1 minute) and neutralizing treatment
(immersing in OPC-B303 neutralizing agent of Okuno Chemical
Industries 200 ml/l aqueous solution under a temperature of
45.degree. C. for 5 minutes, then washing with water for 1 minute)
processes. Moreover, a copper layer with a thickness of 1 .mu.m was
formed with an electroless plating solution (ATS AddCopper CT, made
by Okuno Chemical Industries) and heated in a furnace at
130.degree. C. for 2 hours, and electrolytic copper plating at 1.5
ampere/dm.sup.2 for 70 minutes was conducted with a copper sulfate
plating solution to prepare a laminate having a copper layer with a
thickness of 20 .mu.m formed. The evaluation result is shown in
Table 7.
TABLE-US-00004 TABLE 4 Comparative Comparative Comparative Example
1 Example 2 Example 3 Comparative Synthesis 100 Example 1 (e-1)
Comparative Synthesis 100 100 Example 2 (e-2) Name of copper foil
GTS-MP GTS-MP FWG-WS Plated copper adhesion 0.19 0.43 1.05 strength
after desmear treatment (kgf/cm) Heat resistance (min) 0 0 0 Heat
resistance evaluated X X X swollen portion Heat resistance under
moisture absorption 1 hour treatment xxx xxx
.largecircle..largecircle..largecircle. 3 hour treatment xxx xxx
xxx 5 hour treatment xxx xxx xxx
TABLE-US-00005 TABLE 5 Comparative Comparative Comparative
Comparative Example 4 Example 5 Example 6 Example 7 Comparative
Synthesis Example 1 (e-1) 100 Comparative Synthesis Example 2 (e-2)
100 100 100 BMI80 100 100 BMI 100 100 Name of copper foil GTS-MP
GTS-MP GTS-MP FWG-WS Plated copper adhesion strength after 0.16
0.44 0.42 0.96 desmear treatment (kgf/cm) Heat resistance (min) 0 0
2.9 3.8 Heat resistance evaluated swollen portion X X X X Heat
resistance under moisture absorption 1 hour treatment xxx xxx xxx
.largecircle..largecircle..largecircle. 3 hour treatment xxx xxx
xxx .largecircle..largecircle..largecircle. 5 hour treatment xxx
xxx xxx .largecircle.xx
TABLE-US-00006 TABLE 6 Comparative Comparative Comparative
Comparative Comparative Example 8 Example 9 Example 10 Example 11
Example 12 Comparative Synthesis Example 1 (a-1) 100 100
Comparative Synthesis Example 2 (a-2) 100 100 100 BMI80 100 100 100
C06 70 70 140 140 140 Inorganic filler content by volume (%) 23.1
23.1 20.1 20.1 20.1 Name of copper foil GTS-MP GTS-MP GTS-MP GTS-MP
FWG-WS Plated copper adhesion strength after 0.14 0.36 0.18 0.33
0.80 desmear treatment (kgf/cm) Heat resistance (min) 0 0 1.3 3.3
3.9 Heat resistance evaluated swollen portion X X X X X Heat
resistance under moisture absorption 1 hour treatment xxx xxx xxx
xxx .largecircle..largecircle..largecircle. 3 hour treatment xxx
xxx xxx xxx .largecircle..largecircle..largecircle. 5 hour
treatment xxx xxx xxx xxx .largecircle.xx
TABLE-US-00007 TABLE 7 Comparative Comparative Comparative Example
13 Example 14 Example 15 Synthesis Example 1 (a-1) 100 100 100
BMI80 100 100 C06 140 Inorganic filler content by 20.1 volume (%)
Name of copper foil GTS-MP GTS-MP GTS-MP Plated copper adhesion
0.32 0.31 0.37 strength after desmear treatment (kgf/cm) Heat
resistance (min) 0 0 0 Heat resistance evaluated X X X swollen
portion Heat resistance under moisture absorption 1 hour treatment
xxx .largecircle..largecircle..largecircle.
.largecircle..largecircle..largecircle. 3 hour treatment xxx
.largecircle.xx .largecircle.xx 5 hour treatment xxx xxx xxx
[0137] As apparent from Examples and Comparative Examples, by using
a resin composite electrolytic copper foil having a block
copolymerized polyimide resin (a) with a structure that an imide
oligomer of a first structural unit bonded to the end of an imide
oligomer of a second structural unit and an imide oligomer of the
second structural unit bonded to the end of an imide oligomer of
the first structural unit are alternately repeated, a resin
comprising the block copolymerized polyimide resin (a) and a
maleimide compound, or compositions thereof containing an inorganic
filler formed on a roughened surface side of an electrolytic copper
foil (A) having a surface roughness Rz of 1.0 to 3.0 .mu.m, a
lightness value of not more than 30 and many (200 to 25000) minute
projections with a height of 1 to 3 .mu.m formed by the above
roughening particles located in an area of 100 .mu.m.times.100
.mu.m, copper foil adherence strength and plate adherence strength
remarkably improved, and good adherence strength could be ensured
without decreasing the adherence strength of plated copper after
desmear treatment. Moreover, it is clear that heat resistance
improved by containing an inorganic filler.
* * * * *