U.S. patent application number 11/387949 was filed with the patent office on 2006-07-27 for multilayered metal laminate and process for producing the same.
This patent application is currently assigned to TOYO KOHAN CO., LTD.. Invention is credited to Shinji Ohsawa, Hiroaki Okamoto, Kinji Saijo, Kazuo Yoshida.
Application Number | 20060163329 11/387949 |
Document ID | / |
Family ID | 18797218 |
Filed Date | 2006-07-27 |
United States Patent
Application |
20060163329 |
Kind Code |
A1 |
Saijo; Kinji ; et
al. |
July 27, 2006 |
Multilayered metal laminate and process for producing the same
Abstract
An adhesive-free multilayered metal laminate having a given
thickness which is obtained by bonding a metal sheet having a thin
metal film on a surface thereof to a metal foil without using an
adhesive; and a process for continuously producing the laminate.
The process comprises the steps of; setting a metal sheet on a reel
for metal sheet unwinding; setting a metal foil on a reel for metal
foil unwinding; unwinding the metal sheet from the metal
sheet-unwinding reel and activating a surface of the metal sheet to
thereby form a first thin metal film on the metal sheet surface;
unwinding the metal foil from the metal foil-unwinding reel and
activating a surface of the metal foil to thereby form a second
thin metal film on the metal foil surface; and press-bonding the
activated surface of the first thin metal film to that of the
second thin metal film so that the first thin metal film formed on
the metal sheet is in contact with the second thin metal film
formed on the metal foil.
Inventors: |
Saijo; Kinji;
(Yamaguchi-ken, JP) ; Yoshida; Kazuo;
(Yamaguchi-ken, JP) ; Okamoto; Hiroaki;
(Yamaguchi-ken, KR) ; Ohsawa; Shinji;
(Yamaguchi-ken, JP) |
Correspondence
Address: |
BROWDY AND NEIMARK, P.L.L.C.;624 NINTH STREET, NW
SUITE 300
WASHINGTON
DC
20001-5303
US
|
Assignee: |
TOYO KOHAN CO., LTD.
Tokyo
JP
|
Family ID: |
18797218 |
Appl. No.: |
11/387949 |
Filed: |
March 24, 2006 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10399530 |
Sep 29, 2003 |
|
|
|
PCT/JP01/08756 |
Oct 4, 2001 |
|
|
|
11387949 |
Mar 24, 2006 |
|
|
|
Current U.S.
Class: |
228/115 |
Current CPC
Class: |
Y10T 428/12438 20150115;
Y10T 428/12896 20150115; H05K 3/025 20130101; H05K 2203/068
20130101; Y10T 428/12 20150115; H05K 2201/0361 20130101; Y10T
428/12979 20150115; H05K 2203/0384 20130101; B23K 20/04 20130101;
B32B 15/01 20130101; H05K 2201/0355 20130101; H05K 3/062
20130101 |
Class at
Publication: |
228/115 |
International
Class: |
B23K 31/02 20060101
B23K031/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 18, 2000 |
JP |
2000-318626 |
Claims
1. A process for producing a multilayered metal laminate, which
comprises setting a metal sheet on a reel for metal sheet
unwinding, setting the metal foil on a reel for metal foil
unwinding, unwinding the metal sheet from the metal sheet-unwinding
reel and activating a surface of the metal sheet to form a first
thin metal film on the metal sheet surface, unwinding the metal
foil from the metal foil-unwinding reel and activating a surface of
the metal foil to form a second thin metal film on the metal sheet
surface, and press-bonding the activated surface of the first thin
metal film to that of the second thin metal surface.
2. A process for producing a multilayered metal laminate, which
comprises setting a metal sheet on a reel for metal sheet
unwinding, setting a metal foil on a reel for metal foil unwinding,
unwinding the metal sheet from the metal sheet-unwinding reel and
activating a surface of the metal sheet to form a first thin metal
film on the metal sheet surface, unwinding the metal foil from the
metal foil-unwinding reel and activating a surface of the metal
foil, and press-bonding the activated surface of the first thin
metal film to that of the metal foil.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a division of co-pending parent
application Ser. No. 10/399,530, filed Sep. 29, 2003, which is the
national stage under 35 U.S.C. 371 of PCT/JP01/08756, filed Oct. 4,
2001, and claiming priority from Japanese application No.
2003-318626, filed Oct. 18, 2000. The entire contents of which is
hereby incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates to a multilayered metal
laminate which is obtained by laminating a metal sheet with a metal
foil by a method not using an adhesive, and a process for producing
the same.
BACKGROUND ART
[0003] A large number of metal sheet laminates obtained by
laminating metal sheets have been so far proposed. Ordinary metal
sheet laminates have been mainly used in a structural material.
[0004] In recent years, the use of the metal sheet laminate has
been diversified, and it has been required to supply a special
material used for forming a fine shape through etching.
[0005] In an etching material, an alternate laminate of an etching
layer and an etching stop layer, such as a laminate of etching
layer/etching stop layer/etching layer, is needed to form a fine
shape through etching.
[0006] The formation of such an etching stop layer has been so far
performed by a wet plating technique or a clad technique in which
heat diffusion treatment is conducted after hot rolling or cold
rolling.
[0007] Nevertheless, such a technique is problematic in that it
involves an intricate process and is not appropriate for a fine
metal sheet laminate requiring precision.
[0008] The first problem of the invention is to provide a
multilayered metal laminate which has a given thickness and is
adhesive-free and which is obtained by bonding a metal sheet having
a thin metal film previously formed on the surface by a thin film
forming method such as vacuum deposition or sputtering to a metal
foil having a given thickness without using an adhesive.
[0009] Further, the second problem of the invention is to provide a
process in which production of a multilayered metal laminate
including formation of a thin film on a metal sheet and bonding to
a metal foil is continuously performed.
DISCLOSURE OF THE INVENTION
[0010] A multilayered metal laminate of the invention is
characterized in that a surface of a first thin metal film formed
on a surface of a metal sheet is laminated in contact with a
surface of a second thin metal film formed on a surface of a metal
foil.
[0011] In such a multilayered metal laminate, it is preferable that
the metal sheet is a copper sheet, the first thin metal film is
nickel, the metal foil is a copper foil and the second thin metal
film is nickel.
[0012] In such a multilayered metal laminate, it is preferable that
the surface of the first thin metal film formed on the surface of
the metal sheet is laminated in contact with the surface of the
metal foil.
[0013] In such a multilayered metal laminate, it is preferable that
the metal sheet is a copper sheet, the first thin metal film is
aluminum and the metal foil is a copper foil.
[0014] In such a multilayered metal laminate, it is preferable that
the metal sheet is a stainless steel sheet, the first thin metal
film is silver and the metal foil is stainless steel.
[0015] A process for producing a multilayered metal laminate in the
invention is characterized by comprising a step of setting a metal
sheet on a reel for metal sheet unwinding, a step of setting a
metal foil on a reel for metal foil unwinding, a step of unwinding
the metal sheet from the metal sheet-unwinding reel and activating
a surface of the metal sheet to form a first thin metal film on the
metal sheet surface, a step of unwinding the metal foil from the
metal foil-unwinding reel and activating a surface of the metal
foil to form a second thin metal film on the metal sheet surface,
and a step of press-bonding the activated surface of the first thin
metal film to that of the second thin metal film.
[0016] A process for producing a multilayered metal laminate in the
invention is characterized by comprising a step of setting a metal
sheet on a reel for metal sheet unwinding, a step of setting a
metal foil on a reel for metal foil unwinding, a step of unwinding
the metal sheet from the metal sheet-unwinding reel and activating
a surface of the metal sheet to form a first thin metal film on the
metal sheet surface, a step of unwinding the metal foil from the
metal foil-unwinding reel and activating a surface of the metal
foil, and a step of press-bonding the activated surface of the
first thin metal film to that of the metal foil.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a sectional view of a multilayered metal
laminate.
[0018] FIG. 2 is a sectional view of a thin metal film
laminate.
[0019] FIG. 3 is a schematic view showing a production process.
[0020] FIG. 4 is a schematic view showing a production process.
[0021] FIG. 5 is a schematic view showing a production process of
the invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0022] FIG. 1 is a schematic view showing a sectional structure of
the multilayered metal laminate in the invention.
[0023] In FIG. 1, a metal sheet 22 is laminated on a metal foil 26
through a first thin metal film 24. With respect to a material of
the metal sheet 22, its type is not particularly limited so long as
it is a material capable of forming a thin film on a metal sheet.
It is selectively used, as required, according to the use of the
multilayered metal laminate in the invention.
[0024] For example, when the multilayered metal laminate of the
invention is used in a mounting printed board, a copper sheet, a
titanium sheet, a stainless steel sheet, an aluminum sheet and the
like are preferably employed as the material of the metal
sheet.
[0025] The thickness of the metal sheet 22 varies with the use.
When it is used in a mounting printed board, a range of from 10 to
200 .mu.m is preferably used. A range of from 25 to 150 .mu.m is
more preferably used.
[0026] With respect to a material of the first or second thin metal
film 23 or 24, its type is not particularly limited so long as it
is a material having a good adhesion to the metal sheet as a
base.
[0027] For example, when the metal sheet 22 is a copper sheet or a
stainless steel sheet, Fe, Ni, Cr, Pd, Zr, Co, Au, Ag, Sn, Cu, Al
and the like are preferably used as the first or second thin metal
film 23 or 24. A thin metal film comprising plural layers of these
metals is also available. Further, an alloy of these metals is also
available as the thin film.
[0028] The thickness varies with the use. When it is used in a
mounting printed board, a range of from 0.01 to 1 .mu.m is
preferably used. A range of from 0.1 to 0.5 .mu.m is more
preferably used.
[0029] As a material of the metal foil 26, for example, a
single-layer foil such as a copper foil, a nickel foil, an aluminum
foil or an iron foil, a laminated foil (clad material) thereof, an
alloy foil thereof, a rolled sheet thereof and the like can be
used. Further, it is possible to use plated foils obtained by
plating the surfaces thereof. The thickness varies with the use.
When it is used in, for example, a mounting printed board, a range
of from 3 to 100 .mu.m is preferably used. A range of from 10 to 35
.mu.m is more preferably used.
[0030] When the multilayered metal laminate of the invention is
used in a radiation plate, a range of from 50 to 1,000 .mu.m by
which it is somewhat thicker is preferably used for improving heat
conduction.
[0031] The process for producing the multilayered metal laminate in
the invention is described below.
[0032] In the first production process, as shown in FIG. 3, the
metal sheet 22 is set on an unwinding reel 62, and the surface of
the metal sheet 22 is activated using an activation device 70
mounted in an apparatus 50 for producing a multilayered metal
laminate.
[0033] The activation here referred to indicates surface treatment
for removing foreign matters adhered to the surface of the thin
metal film on the metal sheet, such as metal oxides, dust-adhered
matters and oil to improve an adhesion to the metal foil in the
subsequent step. Likewise, the surface of the metal foil 26 is also
activated using an activation device 80.
[0034] With respect to the activation devices 70, 80, a device
having a mechanism capable of cleaning a surface can preferably be
employed. In Examples of the invention, a device that conducts
sputter-etching of respective bonding surfaces of materials to be
press-bonded is employed.
[0035] That is, as shown in FIG. 3, the method of activation by
sputter-etching is performed, as previously disclosed by the
present Applicant in JP-A-1-224184, by (4) conducting
sputter-etching of the metal sheet 22 and the metal foil 26 (1) in
an inert gas atmosphere under a very low pressure of from
1.times.10.sup.1.times.10.sup.-3 Pa such that (2) an alternating
current with from 1 to 50 MHz is applied between one (72) of
electrodes A earthed respectively and another insulated and
supported electrode B (74) to allow glow discharge and (3) an area
a of an electrode roll 72 or 82 exposed to plasma generated by the
glow discharge is less than 1/3 an area b of an electrode 74 or 84.
This is preferable because the surface can be activated a
thigh-speed. In the foregoing structure, ion impact occurs
preferentially on the side of the electrode A for a material to be
etched, and little occurs on the side of the electrode B.
[0036] Incidentally, the surface activation can also be performed
using an ion gun or the like in which the surface activation is
performed at high speed.
[0037] A method in which the first thin metal film 24 is formed on
the surface of the metal sheet 22 and the second thin metal film 23
is formed on the surface of the metal foil 26 is described
below.
[0038] For this purpose, a thin film forming unit 90 for forming
the first thin metal film 24 on the metal sheet 22 is mounted in
the later step of the activation device 70 within a vacuum
container 52.
[0039] That is, as shown in FIG. 3, the alternating current with
from 1 to 50 MHz is applied between the one earthed electrode A
(electrode roll 72) and the other insulated and supported electrode
B (76) to allow the glow discharge.
[0040] In this case, an area a of the electrode roll 72 exposed to
plasma generated by the glow discharge is adapted to be at least
three times an area b of the electrode 76, whereby the first thin
metal film 24 is formed on the surface of the metal sheet 22
without etching the surface of the metal sheet 22.
[0041] That is, in a sputter unit for conducting formation of a
thin film, an area ratio of opposite electrodes a and b is the
inverse of that in the activation, whereby ion impact can be
applied to the target side to form a thin film on a metal
sheet.
[0042] A sputter unit employed as an example of the thin film
forming unit 90 used in the invention is described by referring to
FIG. 4.
[0043] The sputter unit 90 comprises a combination of a target
electrode 94 caused to electrically float and the water-cooled
earthed electrode roll 72. A target 92 for forming the first thin
metal film 24 is put on the target electrode 94, and a magnet 98 is
also put thereon to improve a sputtering efficiency by a magnetic
field. Further, for preventing the target 92 from being abnormally
heated, the target electrode 94 is adapted to be water-cooled.
[0044] In performing the sputtering, the pressure is maintained at
1.times.10.sup.-3 Pa or less, and an inert gas such as argon, neon,
xenon or krypton and a gas such as oxygen are then introduced into
the vacuum container 52 to provide a gaseous atmosphere of from
1.times.10.sup.1 to 1.times.10.sup.-3 Pa.
[0045] Then, a high-frequency power supply 96 is loaded on the
target electrode 94 to generate plasma between the target electrode
94 and the electrode roll 72, whereby ion impact is applied to the
target 92.
[0046] Target atoms are thereby released to form the first thin
metal film 24 on the metal sheet 22.
[0047] Likewise, the metal foil 26 to be laminated is also
activated using the activation device 80, and the second thin metal
film 23 is formed on the surface of the metal foil 26 using a thin
metal film forming unit 95 which is the same as the thin film
forming unit 90.
[0048] Further, as shown in FIG. 5, the second thin metal film 23
can be multilayered by installing plural electrodes 76 and
arranging plural thin film forming units 91. Such thin metal films
may be the same types or the different types. Still further, even
when the plural electrodes 76 are installed, no metal thin film can
be formed at all by switching off power supplies of the electrodes.
Furthermore, plural layers of thin films can also be formed by
switching off some power supplies.
[0049] As a method for forming the first and second thin metal
films, a known method such as a sputtering method, an ion plating
method or a vacuum deposition method (refer to JP-A-8-231717) can
be used.
[0050] Moreover, when the surface of the metal sheet 22 or the
metal foil 26 is roughened, the adhesion strength with the thin
metal film is preferably improved.
[0051] Then, the activated surfaces are superposed, and bonded by
press-bonding with a press-bonding unit 60, whereby the
multilayered metal laminate 20 is produced within the same vacuum
container in one process.
[0052] The press-bonding is preferably light press-bonding so as to
prevent damage of the metal foil or the thin metal film. When it is
numerically expressed in terms of, for example, a draft, a range of
from 0.1 to 10% is preferable.
EXAMPLES
[0053] Examples are described below by referring to the
drawings.
Example 1
[0054] A copper sheet having a thickness of 100 .mu.m was used as a
metal sheet. Further, a copper foil having a thickness of 18 .mu.m
was used as a metal foil.
Activation
[0055] The copper sheet 22 unwound from the metal sheet-unwinding
reel 62 and the copper foil 26 unwound from the metal
foil-unwinding reel 64 were wound respectively on the water-cooled
electrode rolls 72, 82 in the vacuum container 52, and activated in
the activation unit 70 by a sputter-etching method.
(2) Formation of a Thin Metal Film
[0056] After the copper sheet 22 was activated, it was sent to the
sputter unit 90 while being wound on the water-cooled electrode
roll 72 to form a thin nickel film having a thickness of 0.2 .mu.m
as the thin metal film 24.
[0057] Further, after the copper foil 26 was activated, it was sent
to the sputter unit 95 while being wound on the water-cooled
electrode roll 82 to form a thin nickel film having a thickness of
0.2 .mu.m as the thin metal film 23.
(3) Press-Bonding
[0058] The bonding surfaces of the copper sheet 22 having the metal
thin film 24 of nickel formed on the surface and the copper foil 26
having the thin metal film 23 of nickel formed on the surface were
superposed, and subjected to cold-press-bonding with a low draft of
0.5% to produce a multilayered metal laminate comprising four
layers of the copper sheet, the thin nickel film, the thin nickel
film and the copper foil.
Example 2
[0059] A copper sheet having a thickness of 100 .mu.m was used as a
metal sheet. Further, a copper foil having a thickness of 35 .mu.m
was used as a metal foil.
(1) Activation
[0060] The copper sheet 22 unwound from the metal sheet-unwinding
reel 62 and the copper foil 26 unwound from the metal
foil-unwinding reel 64 were wound respectively on the water-cooled
electrode rolls 72, 82 in the vacuum container 52, and activated in
the activation unit 70 by a sputter-etching method.
(2) Formation of a Thin Metal Film
[0061] After the copper sheet 22 was activated, it was sent to the
sputter unit 90 while being wound on the water-cooled electrode
roll 72 to form a thin aluminum film having a thickness of 0.5
.mu.m as the thin metal film 24.
[0062] Further, after the copper foil 26 was activated, it was
passed through the sputter unit 95 while being wound on the
water-cooled electrode roll 82. However, a power supply was
switched off, and a thin metal film was not formed.
(3) Press-Bonding
[0063] The bonding surfaces of the copper sheet 22 having the thin
aluminum film as the metal thin film 24 formed on the surface and
the copper foil 26 subjected to the surface activation were
superposed, and subjected to cold-press-bonding with a low draft of
0.5% to produce a multilayered metal laminate comprising three
layers of the copper sheet, the thin aluminum film and the copper
foil.
INDUSTRIAL APPLICABILITY
[0064] Since the multilayered metal laminate of the invention is
one obtained by press-bonding within the vacuum container without
using an adhesive, the metal foil and the metal sheet can be
produced with a uniform thickness.
[0065] Further, since the surface activation, the formation of the
thin metal film and the press-bonding are performed in one process,
the multilayered metal laminate can easily be obtained. Moreover,
since the surface activation and the formation of the thin metal
film are conducted on the same electrode rolls, the apparatus can
be rendered compact.
* * * * *