U.S. patent application number 15/202870 was filed with the patent office on 2017-01-12 for heat-curable resin composition for semiconductor encapsulation.
This patent application is currently assigned to Shin-Etsu Chemical Co., Ltd.. The applicant listed for this patent is Shin-Etsu Chemical Co., Ltd.. Invention is credited to Naoyuki KUSHIHARA, Kazuaki SUMITA.
Application Number | 20170009007 15/202870 |
Document ID | / |
Family ID | 56551141 |
Filed Date | 2017-01-12 |
United States Patent
Application |
20170009007 |
Kind Code |
A1 |
SUMITA; Kazuaki ; et
al. |
January 12, 2017 |
HEAT-CURABLE RESIN COMPOSITION FOR SEMICONDUCTOR ENCAPSULATION
Abstract
Provided is a versatile heat-curable resin composition for
semiconductor encapsulation that has a favorable water resistance
and abradability, and exhibits a superior fluidity and a small
degree of warpage even when used to perform encapsulation on a
large-size wafer. The heat-curable resin composition of the
invention contains: (A) a cyanate ester compound having not less
than two cyanato groups in one molecule; (B) a phenol curing agent
containing a resorcinol-type phenolic resin; (C) a curing
accelerator; and (D) a spherical inorganic filler.
Inventors: |
SUMITA; Kazuaki;
(Annaka-shi, JP) ; KUSHIHARA; Naoyuki;
(Annaka-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Shin-Etsu Chemical Co., Ltd. |
Tokyo |
|
JP |
|
|
Assignee: |
Shin-Etsu Chemical Co.,
Ltd.
Tokyo
JP
|
Family ID: |
56551141 |
Appl. No.: |
15/202870 |
Filed: |
July 6, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 21/56 20130101;
C08K 9/06 20130101; C08G 2261/143 20130101; C08G 61/10 20130101;
C08G 2190/00 20130101; C08K 2201/003 20130101; H01L 23/295
20130101; C08G 73/026 20130101; C08G 2261/312 20130101; C08G 73/00
20130101 |
International
Class: |
C08G 61/10 20060101
C08G061/10; H01L 21/56 20060101 H01L021/56; H01L 23/29 20060101
H01L023/29; C08K 9/06 20060101 C08K009/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 7, 2015 |
JP |
2015-135799 |
Claims
1. A heat-curable resin composition for semiconductor
encapsulation, comprising: (A) a cyanate ester compound having not
less than two cyanato groups in one molecule, said cyanate ester
compound containing a cyanate ester compound (A-1) represented by
the following formula (1) and exhibiting a viscosity of not higher
than 50 Pas when measured by a B-type rotary viscometer at
23.degree. C. in accordance with a method described in JIS
K7117-1:1999 ##STR00012## wherein n represents an integer of 0 or
1; each of R.sup.1 and R.sup.2 represents a hydrogen atom or an
alkyl group having 1 to 4 carbon atoms; and R.sup.3 represents a
divalent linking group selected from the groups expressed by the
following formulae (2) to (5) ##STR00013## (B) a phenol curing
agent containing a resorcinol-type phenolic resin represented by
the following formula (6) ##STR00014## wherein n represents an
integer of 0 to 10; each of R.sup.1 and R.sup.2 independently
represents a hydrogen atom or a monovalent group selected from the
group consisting of an alkyl group having 1 to 10 carbon atoms, an
allyl group and a vinyl group; (C) a curing accelerator; and (D) an
inorganic filler that is spherical, has an average particle
diameter of 1 to 20 .mu.m when measured by a laser diffraction
method, has been surface-treated with a silane coupling agent
represented by the following formula (7) and is added in an amount
of 1,200 to 2,200 parts by mass with respect to 100 parts by mass
of a sum total of said components (A) and (B)
R.sup.1.sub.a(OR.sup.2).sub.(3-a)Si--C.sub.3H.sub.6--R.sup.3 (7)
wherein a represents an integer of 0 to 3; R.sup.1 represents a
methyl group or an ethyl group; R.sup.2 represents an alkyl group
having 1 to 3 carbon-atoms; and R.sup.3 represents a group selected
from the group consisting of the nitrogen-containing functional
groups represented by the following formulae (8) to (11).
##STR00015##
2. The heat-curable resin composition for semiconductor
encapsulation according to claim 1, wherein said component (A)
contains two or more kinds of cyanate ester compounds including at
least one kind of said cyanate ester compound (A-1), and said
cyanate ester compound (A-1) is in an amount of not smaller than
90% by mass, but smaller than 100% by mass with respect to a whole
amount of said component (A) added.
3. The heat-curable resin composition for semiconductor
encapsulation according to claim 1, wherein said resorcinol-type
phenolic resin represented by the following formula (6) is in an
amount of 10 to 100% by mass with respect to a whole amount of said
component (B) added, and cyanato groups in said cyanate ester
compound as said component (A) are in an amount of 0.5 to 100
equivalents with respect to 1 equivalent of hydroxyl group in said
phenol curing agent as said component (B).
4. The heat-curable resin composition for semiconductor
encapsulation according to claim 2, wherein said resorcinol-type
phenolic resin represented by the following formula (6) is in an
amount of 10 to 100% by mass with respect to a whole amount of said
component (B) added, and cyanato groups in said cyanate ester
compound as said component (A) are in an amount of 0.5 to 100
equivalents with respect to 1 equivalent of hydroxyl group in said
phenol curing agent as said component (B).
5. The heat-curable resin composition for semiconductor
encapsulation according to claim 1, wherein a linear expansion
coefficient thereof is in a range of 3.0 to 5.0 ppm/.degree. C. as
a result of measuring a specimen of a size of 5.times.5.times.15 mm
at an increasing rate of 5.degree. C./min from 25 to 300.degree. C.
while constantly applying a pressure of 19.6 mN, in accordance with
a method described in JIS K 7197:2012.
6. A production method of a resin-encapsulated semiconductor
device, comprising: a step of collectively encapsulating an entire
silicon wafer or entire substrate with at least one semiconductor
element mounted thereon by a cured product of the heat-curable
resin composition for semiconductor encapsulation as set forth in
claim 1, wherein said silicon wafer or substrate has an area of 200
to 1,500 cm.sup.2, and said silicon wafer or substrate exhibits an
amount of warpage of not larger than 2 mm after encapsulation.
7. A production method of a resin-encapsulated semiconductor
device, comprising: a step of collectively encapsulating an entire
silicon wafer or entire substrate with at least one semiconductor
element mounted thereon by a cured product of the heat-curable
resin composition for semiconductor encapsulation as set forth in
claim 2, wherein said silicon wafer or substrate has an area of 200
to 1,500 cm.sup.2, and said silicon wafer or substrate exhibits an
amount of warpage of not larger than 2 mm after encapsulation.
8. A production method of a resin-encapsulated semiconductor
device, comprising: a step of collectively encapsulating an entire
silicon wafer or entire substrate with at least one semiconductor
element mounted thereon by a cured product of the heat-curable
resin composition for semiconductor encapsulation as set forth in
claim 3, wherein said silicon wafer or substrate has an area of 200
to 1,500 cm.sup.2, and said silicon wafer or substrate exhibits an
amount of warpage of not larger than 2 mm after encapsulation.
9. A production method of a resin-encapsulated semiconductor
device, comprising: a step of collectively encapsulating an entire
silicon wafer or entire substrate with at least one semiconductor
element mounted thereon by a cured product of the heat-curable
resin composition for semiconductor encapsulation as set forth in
claim 4, wherein said silicon wafer or substrate has an area of 200
to 1,500 cm.sup.2, and said silicon wafer or substrate exhibits an
amount of warpage of not larger than 2 mm after encapsulation.
10. The production method of the resin-encapsulated semiconductor
device according to claim 6, wherein in the step of said collective
encapsulation, the semiconductor element is encapsulated by
covering the semiconductor element with said heat-curable resin
composition under a pressed condition or under a depressed
condition in vacuum, and then heating and curing said heat-curable
resin composition.
11. The production method of the resin-encapsulated semiconductor
device according to claim 7, wherein in the step of said collective
encapsulation, the semiconductor element is encapsulated by
covering the semiconductor element with said heat-curable resin
composition under a pressed condition or under a depressed
condition in vacuum, and then heating and curing said heat-curable
resin composition.
12. The production method of the resin-encapsulated semiconductor
device according to claim 8, wherein in the step of said collective
encapsulation, the semiconductor element is encapsulated by
covering the semiconductor element with said heat-curable resin
composition under a pressed condition or under a depressed
condition in vacuum, and then heating and curing said heat-curable
resin composition.
13. The production method of the resin-encapsulated semiconductor
device according to claim 9, wherein in the step of said collective
encapsulation, the semiconductor element is encapsulated by
covering the semiconductor element with said heat-curable resin
composition under a pressed condition or under a depressed
condition in vacuum, and then heating and curing said heat-curable
resin composition.
Description
BACKGROUND OF THE INVENTION
[0001] Field of the Invention
[0002] The present invention relates to a heat-curable resin
composition for semiconductor encapsulation; and a semiconductor
device encapsulated by such resin composition.
[0003] Background Art
[0004] In recent years, semiconductor devices have undergone a
tremendous technical innovation. In order for mobile
information-communication terminals such as smart phones and
tablets to be able to process a large volume of information at a
high speed, a TSV (Through Silicon Via) technology is employed to
connect semiconductor elements through multi-layer bonding,
followed by performing flip chip bonding on the multilayered
semiconductor elements on an 8-inch or 12-inch silicon interposer,
and then using a heat-curable resin to encapsulate each interposer
with a plurality of the multilayered semiconductor elements mounted
thereon. The encapsulated package is then divided after abrading
the unwanted cured resin on the semiconductor elements, thus
obtaining a thin and downsized multifunctional semiconductor device
capable of performing high-speed processing.
[0005] Encapsulation molding can be performed without a major
problem even with the current situation, if using a substrate such
as a small-diameter wafer of a size of about 8 inch. However, an
epoxy resin or the like tends to exhibit a significant contraction
stress after encapsulation, in the case of performing molding on a
wafer of a size of not smaller than 12 inches, on a 20-inch wafer
in recent years or on a panel of a size of larger than 20 inches.
For this reason, there has been a problem that a semiconductor
element(s) will be stripped off from a substrate made of a metal or
the like in such case, which makes it impossible to conduct mass
production. In order to solve the aforementioned problems
associated with the increases in diameters of wafers, glass
substrates and metal substrates, it has been required that a resin
be filled with a filler by an amount of not smaller than 90% by
mass, or that a contraction stress at the time of curing be reduced
through a reduction in elasticity of a resin
(JP-A-2012-209453).
[0006] However, in the case where an entire silicon interposer is
to be encapsulated by a heat-curable resin, a significant warpage
will occur due to a difference in thermal expansion coefficient
between the silicon and heat-curable resin. A significant warpage
makes it unsuitable to perform an abrading step and a dicing step
later. That is, it has been a major technical issue to prevent
warpage. In addition, encapsulated layers are getting thicker in
recent years due to stacked semiconductor elements. Thus, a
mainstream semiconductor device has been that of thin-type obtained
by abrading the encapsulated resin layer (JP-A-2014-229771).
[0007] Conventionally, there has been used an encapsulation
material prepared by filling a composition containing an epoxy
resin and a curing agent such as an acid anhydride and a phenolic
resin with a filler by an amount of not smaller than 85% by mass,
and then adding a rubber and/or a thermoplastic resin thereto for
stress relaxation. This type of composition bears a problem that a
warpage will change due to a thermal history associated with a
step(s) in 3D packaging, and that such warpage will then lead to
damages of a semiconductor(s) or even the breakage of a wafer
itself. Meanwhile, since a typical low-elastic resin material such
as a conventional silicone compound is a soft resin, there have
been problems that the soft resin will lead to resin clogging when
being abraded, and that resin cracks will occur during a
reliability test (JP-A-Hei11-289034).
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide a highly
versatile heat-curable resin composition for semiconductor
encapsulation that has a favorable water resistance and
abradability, and exhibits a superior fluidity and a small degree
of warpage even when used to encapsulate a semiconductor element(s)
on a large-size wafer.
[0009] The inventors of the present invention diligently carried
out a series of studies, and completed the invention as follows.
That is, the inventors found that the above objectives could be
achieved by a heat-curable resin composition obtained by combining
a particular cyanate ester compound, a particular phenol curing
agent and a particular inorganic filler. The present invention is
to provide the following heat-curable resin composition for
semiconductor encapsulation; and method for producing a
resin-encapsulated semiconductor device using a cured product of
such composition.
[1]
[0010] A heat-curable resin composition for semiconductor
encapsulation, comprising: [0011] (A) a cyanate ester compound
having not less than two cyanato groups in one molecule, the
cyanate ester compound containing a cyanate ester compound (A-1)
represented by the following formula (1) and exhibiting a viscosity
of not higher than 50 Pas when measured by a B-type rotary
viscometer at 23.degree. C. in accordance with a method described
in JIS K7117-1:1999
##STR00001##
[0012] wherein n represents an integer of 0 or 1; each of R.sup.1
and R.sup.2 represents a hydrogen atom or an alkyl group having 1
to 4 carbon atoms; and R.sup.3 represents a divalent linking group
selected from the groups expressed by the following formulae (2) to
(5)
##STR00002## [0013] (B) a phenol curing agent containing a
resorcinol-type phenolic resin represented by the following formula
(6)
##STR00003##
[0014] wherein n represents an integer of 0 to 10; each of R.sup.1
and R.sup.2 independently represents a hydrogen atom or a
monovalent group selected from the group consisting of an alkyl
group having 1 to 10 carbon atoms, an allyl group and a vinyl
group; [0015] (C) a curing accelerator; and [0016] (D) an inorganic
filler that is spherical, has an average particle diameter of 1 to
20 .mu.m when measured by a laser diffraction method, has been
surface-treated with a silane coupling agent represented by the
following formula (7) and is added in an amount of 1,200 to 2,200
parts by mass with respect to 100 parts by mass of a sum total of
the components (A) and (B)
[0016] R.sup.1.sub.a(OR.sup.2).sub.(3-a)Si--C.sub.3H.sub.6--R.sup.3
(7)
[0017] wherein a represents an integer of 0 to 3; R.sup.1
represents a methyl group or an ethyl group; R.sup.2 represents an
alkyl group having 1 to 3 carbon atoms; and R.sup.3 represents a
group selected from the group consisting of the nitrogen-containing
functional groups represented by the following formulae (8) to
(11).
##STR00004##
[2]
[0018] The heat-curable resin composition for semiconductor
encapsulation according to [1], wherein the component (A) contains
two or more kinds of cyanate ester compounds including at least one
kind of the cyanate ester compound (A-1), and the cyanate ester
compound (A-1) is in an amount of not smaller than 90% by mass, but
smaller than 100% by mass with respect to a whole amount of the
component (A) added.
[3]
[0019] The heat-curable resin composition for semiconductor
encapsulation according to [1] or [2], wherein the resorcinol-type
phenolic resin represented by the following formula (6) is in an
amount of 10 to 100% by mass with respect to a whole amount of the
component (B) added, and cyanato groups in the cyanate ester
compound as the component (A) are in an amount of 0.5 to 100
equivalents with respect to 1 equivalent of hydroxyl group in the
phenol curing agent as the component (B).
[4]
[0020] The heat-curable resin composition for semiconductor
encapsulation according to any one of [1] to [3], wherein a linear
expansion coefficient thereof is in a range of 3.0 to 5.0
ppm/.degree. C. as a result of measuring a specimen of a size of
5.times.5.times.15 mm at an increasing rate of 5.degree. C./min
from 25 to 300.degree. C. while constantly applying a pressure of
19.6 mN, in accordance with a method described in JIS K
7197:2012.
[5]
[0021] A production method of a resin-encapsulated semiconductor
device, comprising: [0022] a step of collectively encapsulating an
entire silicon wafer or entire substrate with at least one
semiconductor element mounted thereon by a cured product of the
heat-curable resin composition for semiconductor encapsulation as
set forth in any one of [1] to [4], wherein [0023] the silicon
wafer or substrate has an area of 200 to 1,500 cm.sup.2, and the
silicon wafer or substrate exhibits an amount of warpage of not
larger than 2 mm after encapsulation. [6]
[0024] The production method of the resin-encapsulated
semiconductor device according to [5], wherein in the step of the
collective encapsulation, the semiconductor element is encapsulated
by covering the semiconductor element with the heat-curable resin
composition under a pressed condition or under a depressed
condition in vacuum, and then heating and curing the heat-curable
resin composition.
[0025] By using the composition of the invention, there can be
provided a semiconductor device having a superior heat resistance
and moisture resistance and barely exhibiting a warpage even after
cooling a heat-cured encapsulated semiconductor element array that
is obtained by mounting at least one semiconductor element on an
inorganic substrate, a metal substrate or an organic substrate with
an adhesive agent (die bonding material); or a heat-cured
encapsulated large-diameter silicon wafer where semiconductor
elements have been fabricated. Further, the present invention
enables collective encapsulation of a whole wafer, and allows an
encapsulation resin to be easily abraded and diced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a diagram showing a method for determining a
glass-transition temperature.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The present invention is described in detail hereunder.
However, the present invention is not limited to the following
examples.
(A) Cyanate Ester Compound
[0028] A component (A) is the main component of the composition of
the present invention. Particularly, the component (A) is a cyanate
ester compound having not less than two cyanato groups, and
includes a compound represented by the following formula (1).
##STR00005##
[0029] (In the formula (1), each of R.sup.1 and R.sup.2 represents
a hydrogen atom or an alkyl group having 1 to 4 carbon atoms;
R.sup.3 represents a divalent linking group selected from the
groups expressed by the following formulae (2) to (5); and n
represents an integer of 0 or 1.)
##STR00006##
[0030] It is preferred that the compound represented by the above
formula (1) exhibit a viscosity of not higher than 50 Pas,
particularly not higher than 20 Pas, at 23.degree. C. when measured
by a B-type rotatory viscometer in accordance with a method as
described in JIS K7117-1:1999. A viscosity greater than 50 Pas
makes it impossible to perform high filling of an inorganic filler,
which leads to a larger expansion coefficient of the cured resin
composition. Therefore, a significant warpage of the cured resin
composition may occur in such case, if the composition of the
invention is to be molded on a wafer of a size of not smaller than
12 inches. Thus, the cured resin composition may not be able to be
formed into a sheet-like shape under such condition.
[0031] It is preferred that the compound represented by the formula
(1) be added in an amount of not smaller than 90% by mass with
respect to the whole cyanate ester compound. If such amount is
smaller than 90% by mass, high filling of an inorganic filler
cannot be performed, which leads to a concern that the cured resin
composition of the present invention may not be able to be formed
into a sheet-like shape.
[0032] In the present invention, one kind of the cyanate ester
compound represented by the formula (1) may be used singularly; or
mixed with an other cyanate ester compound(s) before use, which
makes two or more kinds of them. Other cyanate ester compounds are
defined as a cyanate ester compound other than that represented by
the above formula (1) but still having not less than two cyanato
groups. A known compound of such other cyanate ester compounds may
be used. Examples of such cyanate ester compound include bis
(4-cyanatophenyl) methane; bis (3-methyl-4-cyanatophenyl) methane;
bis (3,5-dimethyl-4-cyanatophenyl) methane; 1,1-bis
(4-cyanatophenyl) ethane; 2,2-bis (4-cyanatophenyl) propane;
2,2-bis (4-cyanatophenyl)-1,1,1,3,3,3-hexafluoropropane; di
(4-cyanatophenyl) thioether; 1,3-dicyanatobenzene;
1,4-dicyanatobenzene; 2-tert-butyl-1,4-dicyanatobenzene;
2,4-dimethyl-1,3-dicyanatobenzene;
2,5-di-tert-butyl-1,4-dicyanatobenzene;
tetramethyl-1,4-dicyanatobenzene; 1,3,5-tricyanatobenzene;
2,2'-dicyanatobiphenyl; 4,4'-dicyanatobiphenyl;
3,3',5,5'-tetramethyl-4,4'-dicyanatobiphenyl;
1,3-dicyanatonaphthalene; 1,4-dicyanatonaphthalene;
1,5-dicyanatonaphthalene; 1,6-dicyanatonaphthalene;
1,8-dicyanatonaphthalene; 2,6-dicyanatonaphthalene;
2,7-dicyanatonaphthalene; 1,3,6-tricyanatonaphthalene; 1,1,1-1 tris
(4-cyanatophenyl) ethane; bis (4-cyanatophenyl) ether;
4,4'-(1,3-phenylenediisopropylidene) diphenylcyanate; bis
(4-cyanatophenyl) thioether; bis (4-cyanatophenyl) sulfone; tris
(4-cyanatophenyl) phosphine; a phenol novolac-type cyanate; a
cresol novolac-type cyanate; and a dicyclopentadiene novolac-type
cyanate.
[0033] It is preferred that the cyanate ester compound as the
component (A) be added in an amount of 80 to 99% by mass, more
preferably 85 to 99% by mass, most preferably 90 to 97% by mass,
with respect to the whole resin composition.
(B) Phenol Curing Agent
[0034] A component (B) is a phenol curing agent containing a
resorcinol-type phenolic resin represented by the following formula
(6).
##STR00007##
[0035] (In the formula (6), n represents an integer of 0 to 10;
each of R.sup.1 and R.sup.2 independently represents a hydrogen
atom or a monovalent group selected from the group consisting of an
alkyl group having 1 to 10 carbon atoms, an allyl group and a vinyl
group.)
[0036] It is preferred that "n" in the above formula (6) be 0 to 10
in terms of melt fluidity of the resin composition. If "n" is
greater than 10, the resin composition will not melt at a
temperature of 100.degree. C. or lower, thus resulting in an
impaired fluidity. As such component (B), there may be used in
combination two or more kinds of the resorcinol-type phenolic
resins (formula (6)) with different values of "n," or there may be
used a resorcinol-type phenolic resin (formula (6)) whose value of
"n" ranges in distribution. It is preferred that each of R.sup.1
and R.sup.2 in the formula (6) be a hydrogen atom or a monovalent
group selected from the group consisting of an alkyl group having 1
to 10 carbon atoms, an allyl group and a vinyl group. It is
particularly preferred that each of these R.sup.1 and R.sup.2 be a
hydrogen atom or a monovalent group selected from the group
consisting of an alkyl group having 1 to 4 carbon atoms, an allyl
group and a vinyl group. R.sup.1 and R.sup.2 may represent
functional groups that differ from each other. Here, when employing
a group having more than 10 carbon atoms, a sufficient heat
resistance of the cured resin composition cannot be achieved if the
group employed is an aliphatic group; whereas the melt fluidity of
the resin composition will be impaired if the group employed is an
aryl group.
[0037] As for a compounding ratio between the component (A) and the
phenol curing agent (B), it is preferred that the cyanato groups
(CN groups) in the cyanate ester compound as the component (A) and
having not less than two cyanato groups (CN groups) be in an amount
of 0.5 to 100 equivalents, more preferably 1 to 50 equivalents,
even more preferably 5 to 35 equivalents, with respect to 1
equivalent of the hydroxyl groups (OH groups) in the
resorcinol-type phenolic resin represented by the formula (6). If
such cyanato groups are in an amount of greater than 100
equivalents, the curing of the resin composition may take place in
an insufficient manner; whereas an amount of smaller than 0.5
equivalents may lead to an impaired heat resistance of the cyanate
ester compound itself.
[0038] By containing the resorcinol-type phenolic resin represented
by the above formula (6), the phenol curing agent is capable of
reducing a resin viscosity at the time of melting the resin
composition; and promoting the curing reaction of the cyanate ester
compound. Further, since the resorcinol-type phenolic resin itself
has a high heat resistance, there can be obtained a cured product
having a superior heat resistance.
(C) Curing Accelerator
[0039] Examples of a component (C) include 1,8-diazabicyclo [5.4.0]
undecene-7 (DBU); 1,5-diazabicyclo [4.3.0] nonene-5 (DBN); N-alkyl
substitution and N-aryl substitution of these compounds; salts of
these nitrogen-containing heterocyclic compounds; and amine-based
curing accelerators. It is preferred that the curing accelerator as
the component (C) be added in an amount of not larger than 5 parts
by mass, more preferably 0.01 to 5 parts by mass, with respect to
100 parts by mass of the cyanate ester resin as the component (A)
and having not less than two cyanato groups.
[0040] Specific examples of a DBU salt include a phenol salt of
DBU, an octylic acid salt of DBU, a p-toluenesulfonic acid salt of
DBU, a formic acid salt of DBU, an orthophthalic acid salt of DBU,
a trimellitic anhydride salt of DBU, a phenol novolac resin salt of
DBU and a tetraphenylborate salt of DBU. Meanwhile, specific
examples of a DBN salt include a phenol salt of DBN, an octylic
acid salt of DBN, a p-toluenesulfonic acid salt of DBN, a formic
acid salt of DBN, an orthophthalic acid salt of DBN, a trimellitic
anhydride salt of DBN, a phenol novolac resin salt of DBN and a
tetraphenylborate salt of DBN.
[0041] Examples of an amine-based curing accelerator include an
aromatic amine-based curing accelerator such as
3,3'-diethyl-4,4'-diaminodiphenylmethane,
3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane,
3,3',5,5'-tetraethyl-4,4'-diaminodiphenylmethane,
2,4-diaminotoluene, 1,4-phenylenediamine, 1,3-phenylenediamine,
diethyltoluenediamine, 3,4'-diaminodiphenyl ether,
3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane,
4,4'-diaminodiphenylmethane, 3,3'-diaminobenzidine, orthotolidine,
3,3'-dimethyl-4,4'-diaminodiphenylmethane, 2,6-diaminotoluene and
1,8-diaminonaphthalene. Other examples of the amine-based curing
accelerator of the present invention include a chain aliphatic
polyamine such as N,N'-bis (3-aminopropyl) ethylenediamine,
3,3'-diaminodipropylamine, 1,8-diaminooctane, 1,10-diaminodecane,
diethylenetriamine, triethylenetetramine and
tetraethylenepentamine; a cycloaliphatic polyamine such as 1,4-bis
(3-aminopropyl) piperazine, N-(2-aminoethyl) piperazine,
N-(2-aminoethyl) morpholine and isophoronediamine; polyamidoamine;
an imidazole-based curing accelerator; and a guanidine-based curing
accelerator. The aforementioned polyamidoamine is prepared by
condensation of dimer acid and polyamine. Examples of such
polyamidoamine include adipic acid dihydrazide and
7,11-octadecadiene-1,18-dicarbohydrazide. Examples of the
aforementioned imidazole-based curing accelerator include
2-methylimidazole, 2-ethyl-4-methylimidazole and 1,3-bis
(hydrazinocarbonoethyl)-5-isopropylhydantoin. Examples of the
aforementioned guanidine-based curing accelerator include aliphatic
amines such as 1,3-diphenylguanidine and 1,3-o-triguanidine.
Particularly, it is preferred that a tertiary amine, a tertiary
amine salt or an imidazole-based curing accelerator be used.
(D) Inorganic Filler
[0042] As an inorganic filler added to the composition of the
present invention, there may be used those normally added to an
epoxy resin composition. Specific examples of such inorganic filler
include silicas such as a molten silica and a crystalline silica;
alumina; silicon nitride; aluminum nitride; boron nitride; titanium
oxide; and glass fibers.
[0043] It is preferred that such inorganic filler be spherical; and
have an average particle diameter of 1 to 20 .mu.m, particularly 3
to 15 .mu.m when measured by a laser diffraction method. Moreover,
such inorganic filler is surface-treated with a silane coupling
agent represented by the following formula (7).
R.sup.1.sub.a(OR.sup.2).sub.(3-a)Si--C.sub.3H.sub.6--R.sup.3
(7)
[0044] (In the formula (7), R.sup.1 represents a methyl group or an
ethyl group; R.sup.2 represents an alkyl group having 1 to 3 carbon
atoms; R.sup.3 represents a group selected from the group
consisting of the nitrogen-containing functional groups represented
by the following formulae (8) to (11); and a represents an integer
of 0 to 3.)
##STR00008##
[0045] The above treatment leads to a superior affinity for the
cyanate ester, and is capable of strengthening the bond with the
inorganic filler and significantly improving the fluidity of the
composition. A known method may be employed as such surface
treatment method using the silane coupling agent. In fact, there
are no particular restrictions on this surface treatment
method.
[0046] It is preferred that the silane coupling agent represented
by the formula (7) be added in an amount of 0.2 to 0.5 parts by
mass with respect to 100 parts by mass of the inorganic filler.
When the silane coupling agent is added in a small amount, the
cyanate ester and the inorganic filler may not be bonded
sufficiently, or there may not be achieved a sufficient fluidity of
the composition. Meanwhile, a larger expansion coefficient may be
resulted if the silane coupling agent is added in a large
amount.
[0047] It is preferred that the component (D) be added in an amount
of 1,200 to 2,200 parts by mass, more preferably 1,400 to 2,000
parts by mass, with respect to 100 parts by mass of a sum total of
the components (A) and (B). When the component (D) is added in an
amount smaller than such lower limit value, a post-molding warpage
of the cured resin composition becomes significant in a way such
that there cannot be achieved a sufficient strength thereof.
Further, an amount larger than such upper limit value leads to a
significantly impaired fluidity of the resin composition in a way
such that a semiconductor element(s) arranged on a submount cannot
be completely encapsulated.
(E) Other Additives
[0048] The heat-resistant resin composition of the present
invention is obtained by combining the above components (A) to (D)
in given amounts. However, other additives may also be added to the
composition of the invention if necessary, without impairing the
objectives and effects of the present invention. Examples of such
additives include an inorganic filler, a mold release agent, a
flame retardant, an ion trapping agent, an antioxidant, an adhesion
imparting agent, a low stress agent and a coloring agent.
[0049] The flame retardant is added to impart a flame retardant
property. Here, all the known flame retardants may be used in the
present invention. Examples of such flame retardant include a
phosphazene compound, a silicone compound, a zinc
molybdate-supported talc, a zinc molybdate-supported zinc oxide,
aluminum hydroxide, magnesium hydroxide and molybdenum oxide.
[0050] The ion trapping agent is added to trap the ion impurities
contained in the resin composition, and avoid a thermal degradation
and a moisture absorption degradation. Here, all the known ion
trapping agents may be used in the present invention. Examples of
such ion trapping agents include hydrotalcites, a bismuth hydroxide
compound and rare-earth oxides.
[0051] The adhesion imparting agent is added to impart an adhesion
with respect to a chip and a substrate that are encapsulated. Here,
all the known adhesion imparting agents may be used in the present
invention. Examples of such adhesion imparting agents include a
silane compound and a polysiloxane compound each having in
molecules a hydrolyzable silyl group(s); and an adhesive functional
group(s) such as a vinyl group, an amino group, an epoxy group,
(metha) acrylic group and a mercapto group.
[0052] Examples of such silane compound include
vinyltrimethoxysilane, vinyltriethoxysilane,
2-(3,4-epoxycyclohexyl) ethyltrimethoxysilane,
.gamma.-glycidoxypropyltrimethoxysilane,
.gamma.-glycidoxypropyltriethoxysilane,
.gamma.-glycidoxypropylmethyldiethoxysilane,
.gamma.-methacryloxypropylmethyldiethoxysilane,
.gamma.-acryloxypropyltrimethoxysilane,
N-2-(aminoethyl)-3-aminopropyltrimethoxysilane,
N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane,
N-phenyl-3-aminopropyltrimethoxysilane,
.gamma.-aminopropyltrimethoxysilane and
.gamma.-mercaptopropyltrimethoxysilane. Further, the above
polysiloxane compound may be circular, chainlike or netlike.
[0053] Although the amount of the component (E) added varies
depending on the intended purpose of the composition, it is
normally added in an amount of not larger than 20% by mass with
respect to the whole composition.
Production Method of Heat-Curable Resin Composition of the
Invention
[0054] The heat-curable resin composition of the present invention
can, for example, be prepared through the method shown below.
[0055] In the beginning, a mixture of the components (A) and (B) is
obtained by simultaneously or separately mixing, stirring, and/or
dispersing the cyanate ester compound (A) and the phenol curing
agent (B) while performing a heating treatment if necessary. A
mixture of the components (A) to (C) is then obtained by mixing,
stirring, and/or dispersing the curing accelerator (C) and the
mixture of the components (A) and (B). Further, a mixture of the
components (A) to (D) is obtained by mixing, stirring, and/or
dispersing the inorganic filler (D) and the mixture of the
components (A) to (C). In addition, at least one of the mold
release agent, flame retardant and ion trapping agent as an
additive(s) may be added to mixed with the mixture of the
components (A) and (B), the mixture of the components (A) to (C),
and the mixture of the components (A) to (D).
[0056] There are no particular restrictions on a device(s) for
performing, for example, mixing, stirring and dispersion. However,
specific examples of such device(s) include a kneader equipped with
a stirring and heating devices, a twin-roll mill, a triple-roll
mill, a ball mill, a continuous extruder, a planetary mixer and a
mass-colloider. These devices may also be appropriately used in
combination.
[0057] The heat-curable resin composition of the present invention
can be molded through the conventional compression molding or
laminating molding. Particularly, it is preferred that compression
molding be performed. In such case, it is preferred that the
composition be molded at a molding temperature of 160 to
180.degree. C. for 300 to 600 sec, and that post-curing be then
performed at 160 to 180.degree. C. for 1 to 6 hours.
[0058] An insignificant warpage is observed in the composition of
the present invention when molded on 8 inch, 12 inch and 20 inch
wafers. Further, the cured resin composition of the present
invention is superior in mechanical strength and insulation
properties, and a semiconductor device encapsulated by such cured
product is superior in long-term reliability. Moreover, the
composition of the invention is also superior in productivity due
to the fact that molding failures such as flow mark and filling
failure will not occur even when using the device(s) for
conventional molding such as compression or laminating molding
under appropriate condition(s) for these device(s).
[0059] A flow mark referred to in this specification is a white
flow mark radially formed from the center of the molded product
toward the outer side. The occurrence of such flow mark may lead
to, for example, a poor appearance; a variation in the properties
of the cured product due to an ununiformly dispersed silica; and an
impaired reliability associated with such variation.
[0060] A filling failure referred to in this specification refers
to a missing portion of resin that occurs on the outer
circumferential region of a wafer. The occurrence of such filling
failure may cause a sensor to erroneously recognize the unfilled
portion as a notch when transporting the wafer in a later step(s).
There, a position adjustment property may be impaired.
Working Example
[0061] Described below are working examples of the present
invention. However, the present invention is not limited to the
following examples. Here, a viscosity referred to in this
specification is a viscosity measured by a B-type rotary viscometer
at 23.degree. C., in accordance with a method described in JIS
K7117-1:1999.
Production Method of Sheet-Like Heat-Curable Resin Composition
[0062] A heat-curable resin composition was obtained by mixing all
the following components as those contained in the heat-curable
resin composition at the ratios shown in Table 1, and then kneading
the same with a twin-roll mill. In Table 1, the unit for the
numerical values representing the compounding ratios is "part by
mass." The mixture of the heat-curable resin composition obtained
above was applied to the surface of a polyester film (protection
layer) treated by a mold release treatment, followed by using a
heated roll mill to form the mixture to a thickness of 100 .mu.m.
In this way, obtained were sheet-like cured products of working
examples 1 to 8 and comparative examples 1 to 7. In comparative
examples 3, 5, 6 and 7, a poor wettability was observed between the
resin and the inorganic filler such that the composition of the
invention failed to be formed into a sheet-like shape. The
following tests and evaluations were then performed on the
compositions that had failed to be formed into a sheet-like
shape(s).
(A) Cyanate Ester Compound
[0063] (A1) 1,1-bis (4-cyanatophenyl) ethane represented by the
following formula (12) (viscosity: 0.08 Pas) (product name: LECY by
LONZA Group Ltd.)
##STR00009##
[0064] (A2) Phenol novolac-type cyanate ester represented by the
following formula (13) (n=0 to 2) (viscosity: 250 Pas) (product
name: PT30 by LONZA Group Ltd.)
##STR00010##
(B) Phenol Curing Agent
[0065] (B1) Resorcinol-type phenolic resin represented by the
following formula (14) (n=0 to 4; each of R.sup.1 and R.sup.2
represents an allyl group; weight-average molecular weight 450 to
600; equivalent 107) (product name: MEH-8400 by MEIWA PLASTIC
INDUSTRIES, LTD)
[0066] (B2) Resorcinol-type phenolic resin represented by the
following formula (14) (n=5 to 7; each of R.sup.1 and R.sup.2
represents an allyl group; weight-average molecular weight 800 to
1,100; equivalent 132) (by MEIWA PLASTIC INDUSTRIES, LTD)
[0067] (B3) Resorcinol-type phenolic resin represented by the
following formula (14) (n=0 to 4; each of R.sup.1 and R.sup.2
represents an n-propyl group; weight-average molecular weight 450
to 600; equivalent 107) (by MEIWA PLASTIC INDUSTRIES, LTD)
[0068] (B4) Resorcinol-type phenolic resin represented by the
following formula (14) (n=0 to 4; each of R.sup.1 and R.sup.2
represents an vinyl group; weight-average molecular weight 450 to
600; equivalent 107) (by MEIWA PLASTIC INDUSTRIES, LTD)
##STR00011##
[0069] (B5) Arylphenol novolac (product name: MEH-8000H by MEIWA
PLASTIC INDUSTRIES, LTD; equivalent 141)
(C) Curing Accelerator
[0070] (C1) DBU-type tetraphenylborate salt (product name: U-CAT
5002 by by San-Apro Ltd.)
(D) Inorganic Filler
[0071] (D1) Treated Silica
[0072] A treated silica (D1) was prepared by performing dry surface
treatment on 100 parts by mass of a spherical molten silica
(spherical molten silica with an average particle diameter of 12
.mu.m (by TATSUMORI LTD.)) with 0.3 parts by mass of an
N-phenyl-3-aminopropyltrimethoxysilane (product name: KBM573 by
Shin-Etsu Chemical Co., Ltd.).
[0073] (D2) Treated Silica
[0074] A treated silica (D2) was prepared by performing dry surface
treatment on 100 parts by mass of a spherical molten silica
(spherical molten silica with an average particle diameter of 12
.mu.m (by TATSUMORI LTD.)) with 0.3 parts by mass of a
.gamma.-glycidoxypropyltrimethoxysilane (product name: KBM403 by
Shin-Etsu Chemical Co., Ltd.).
[0075] (D3) Treated Silica
[0076] A treated silica (D3) was prepared by performing dry surface
treatment on 100 parts by mass of a spherical molten silica
(spherical silica with an average particle diameter of 0.8 .mu.m
(by TATSUMORI LTD.)) with 0.3 parts by mass of the
N-phenyl-3-aminopropyltrimethoxysilane (product name: KBM573 by
Shin-Etsu Chemical Co., Ltd.).
[0077] (D4) Non-Treated Silica
[0078] The spherical molten silica used in (D1) (by TATSUMORI LTD.,
average particle diameter of 12 .mu.m) was used without performing
surface treatment thereon.
(E) Other Additives
[0079] (E1) Adhesion imparting agent:
.gamma.-glycidoxypropyltrimethoxysilane (product name: KBM403 by
Shin-Etsu Chemical Co., Ltd.).
[0080] (E2) Coloring agent: carbon black (product name: Mitsubishi
carbon black 3230MJ by Mitsubishi Chemical Corporation)
Test and Evaluation Method
Glass-Transition Temperature and Linear Expansion Coefficient
[0081] Each of the sheet-like cured products produced in the
working and comparative examples in accordance with JIS K
7197:2012, was processed into a specimen of a size of
5.times.5.times.15 mm, followed by placing the same in a thermal
dilatometer TMA 8140C (by Rigaku Corporation). A change in size of
the specimen was then measured while constantly applying a pressure
of 19.6 mN to the specimen within a temperature from 25.degree. C.
to 300.degree. C. at an increasing ratio of 5.degree. C./min. The
correlation between such change in size and the temperatures was
then plotted on a graph. The glass-transition temperatures in the
working and comparative examples were later obtained based on such
graph showing the correlation between the change in size and the
temperatures, and through the following method for determining the
glass-transition temperature(s). Method for determining
glass-transition temperature
[0082] In FIG. 1, T.sub.1 and T.sub.2 represent two arbitrary
temperatures that are not higher than the temperature at the
inflection point and by which a tangent line to the size
change-temperature curve can be drawn; whereas T.sub.1' and
T.sub.2' represent two arbitrary temperatures that are not lower
than the temperature at the inflection point and by which a similar
tangent line can be drawn. D.sub.1 and D2 individually represent a
change in size at T.sub.1 and a change in size at T.sub.2; whereas
D.sub.1' and D.sub.2' individually represent a change in size at
T.sub.1' and a change in size at T.sub.2'. The glass-transition
temperature (Tg) is then defined as the temperature at the point of
intersection between a straight line connecting points (T.sub.1,
D.sub.1) and (T.sub.2, D.sub.2) and a straight line connecting
points (T.sub.1', D.sub.1') and (T.sub.2', D.sub.2'). The slope
between T.sub.1 and T.sub.2 is defined as a linear expansion
coefficient (linear expansion coefficient 1) of a region where the
temperature is not larger than Tg, whereas the slope between
T.sub.1' and T.sub.2' is defined as a linear expansion coefficient
(linear expansion coefficient 2) of a region where the temperature
is not smaller than Tg.
Evaluation on Existence or Non-Existence of Flow Mark and Filling
Failure
[0083] The liquid resin composition was subjected to compression
molding at 175.degree. C. for 600 sec to obtain a molded product of
a resin thickness of 300 followed by completely curing (i.e.
post-curing) the same under a condition of 180.degree. C. for 1
hour. Later, the existence or non-existence of the flow mark and/or
filling failure was evaluated by visually observing the appearance
of the cured product.
Warpage Measurement
[0084] Using a 12-inch silicon wafer of a thickness of 775 .mu.m,
the liquid resin composition was subjected to compression molding
in a wafer mold by APIC YAMADA CORPORATION at 175.degree. C. for
600 sec to obtain a molded product of a resin thickness of 300
.mu.m, followed by completely curing (i.e. post-curing) the same
under the condition of 180.degree. C. for 1 hour. Warpage (mm) was
measured thereafter.
Reliability Test
[0085] Semiconductor chips were prepared as follows. That is, a
screen printer for thick film (THICK FILM PRINTER TYPE MC 212) was
used to print on an 8-inch silicon wafer of a thickness of 200
.mu.m a die bonding material SFX-513M1 (by Shin-Etsu Chemical Co.,
Ltd.) at a thickness of 20 .mu.m. A dicing apparatus was then used
to cut the printed specimen into 7-mm dices while the specimen was
still in B-stage.
[0086] Next, a flip chip bonder (NM-SB50A by Panasonic Corporation)
was used to bond the die bonding material-adhered semiconductor
chips (7 mm.times.7 mm and 220 .mu.m thickness) to the 8-inch and
200 .mu.m-thick silicon wafer, under a condition of 10N,
150.degree. C. and 1.0 sec. In this way, there was obtained a
silicon wafer with the semiconductor chips mounted thereon and
having a thickness of 200 .mu.m.
[0087] The semiconductor chip-mounted silicon wafer of the
thickness of 200 .mu.m was then placed in a compression molding
device, followed by placing thereon an appropriate amount of the
liquid resin composition so as to cure the liquid resin composition
at 110.degree. C. for 10 min, where a maximum value of the molding
pressure applied was 15 to 30 MPa. A silicon wafer was thus
obtained. The amount of the liquid resin composition was adjusted
to that allowing the resin thickness to become 400 .mu.m.+-.10
.mu.m after molding. Such silicon wafer was then subjected to
post-curing where the silicon wafer was heat-treated in an oven at
150.degree. C. for 2 hours. Later, a dicing apparatus was again
used to cut the post-cured silicon wafer into 7.1 mm.times.7.1 mm
dices, thus obtaining a separated resin-mounted semiconductor chip
having a thickness of 400 .mu.m.
[0088] The flip chip bonder (NM-SB50A by Panasonic Corporation) was
used to bond the separated resin-mounted semiconductor chips to a
BT substrate with a die bonding material SFX-513S (by Shin-Etsu
Chemical Co., Ltd.), under a condition of 10N, 150.degree. C. and
1.5 sec. Post-curing was then performed through a heat treatment in
an oven at 150.degree. C. for 4 hours, thus obtaining a BT
substrate where the resin-mounted semiconductor chips had been
bonded.
[0089] A transfer molding machine (G-LINE Press by APIC YAMADA
CORPORATION) was used to mold a molding compound material to a
thickness of 1.5 mm on the BT substrate where the resin-mounted
semiconductor chips had been bonded, under a molding condition of
175.degree. C., 90 sec and 9 MPa. Later, a dicing apparatus was
again used to cut the BT substrate into 10.0 mm.times.10.0 mm
dices, thus obtaining the separated BT substrate (semiconductor
device) where the molding compound resin-mounted semiconductor chip
had been bonded.
[0090] The above semiconductor device was then subjected to a
hygroscopic treatment for 168 hours under a condition of 85.degree.
C. and 85% RH. The semiconductor device thus treated was further
subjected to a solder heat resistance test (peeling inspection)
where the semiconductor device was inserted through a reflow oven
three times, the reflow oven being previously configured in a
manner such that a temperature range was within 255 to 260.degree.
C. (i.e. maximum temperature 260.degree. C.) for 30 sec.+-.3 sec.
An ultrasonic flaw detector (QUANTUM 350 by SONIX) was used to
inspect a peeling state inside the semiconductor chips in a
nondestructive manner with a 75 MHz probe. Here, examples
exhibiting no peelings or cracks were marked "Favorable," whereas
examples exhibiting peelings or cracks were marked "NG."
Temperature Cycle Test (TCT)
[0091] The separated BT substrate where the molding compound
resin-mounted semiconductor chip had been bonded was subjected to a
cycle of -55.degree. C./15 min and then +125.degree. C./15 min
(Automatic), using a compact thermal shock chamber TSE-11
manufactured by ESPEC CORP. In the beginning, when 0 cycle had yet
elapsed, the ultrasonic flaw detector (QUANTUM 350 by SONIX) was
used to inspect the peeling state inside the semiconductor chip in
the nondestructive manner with the 75 MHz probe. Later, similar
inspections were individually performed after 250 cycles, 500
cycles and 700 cycles had elapsed. The inspection results are shown
in Table 1. Examples where a sum total of peeled areas to an area
of the semiconductor chip was less than 5% (minimal peeling) are
marked "OK (no peeling)," whereas examples where the sum total of
the peeled areas to the area of the semiconductor chip was 5% or
more are marked "NG (peeling occurred)."
TABLE-US-00001 TABLE 1 Comparative Working example example
Composition (part by mass) 1 2 3 4 5 6 7 8 1 (A) Cyanate ester (A1)
95 95 95 95 90 97 95 95 95 compound (A2) 5 (B) Phenol curing agent
(B1) 5 5 3 5 5 (B2) 5 (B3) 5 (B4) 5 (B5) 5 (C) Curing accelerator
(C1) 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 (D) Inorganic filler (D1)
Treated silica 1850 1850 1850 1850 1850 1850 2000 1400 1850 (D2)
Treated silica (D3) Treated silica (D4) Non-treated silica (E)
Other additives (E1) Adhesion imparting agent 1 1 1 1 1 1 1 1 1
(E2) Carbon black 1 1 1 1 1 1 1 1 1 Evaluation item Sheet-like
shape Favor- Favor- Favor- Favor- Favor- Favor- Favor- Favor-
Favor- able able able able able able able able able
Glass-transition 220 225 225 210 240 230 220 220 195
temperature[Tg](.degree. C.) Linear expansion 4.1 4.0 4.0 4.1 4.1
4.0 3.8 4.5 4.3 coefficient(ppm/.degree. C.) Flow mark
(Yes.cndot.No) No No No No No No No No No Filling failure
(Yes.cndot.No) No No No No No No No No No Warpage amount(mm) <1
<1 <1 <1 <1 <1 <1 2 8 Reliability test Presence
or absence Favor- Favor- Favor- Favor- Favor- Favor- Favor- Favor-
NG of peeling, crack able able able able able able able able (IR
reflow) Temperature cycle test 0 cycles OK OK OK OK OK OK OK OK NG
250 cycles OK OK OK OK OK OK OK OK NG 500 cycles OK OK OK OK OK OK
OK OK NG 750 cycles OK OK OK OK OK OK OK OK NG Comparative example
Composition (part by mass) 2 3 4 5 6 7 (A) Cyanate ester (A1) 90 95
95 95 95 95 compound (A2) (B) Phenol curing agent (B1) 5 5 5 5 5
(B2) (B3) (B4) (B5) 10 (C) Curing accelerator (C1) 0.5 0.5 0.5 0.5
0.5 0.5 (D) Inorganic filler (D1) Treated silica 1850 1150 2300
(D2) Treated silica 1850 (D3) Treated silica 1850 (D4) Non-treated
silica 1850 (E) Other additives (E1) Adhesion imparting agent 1 1 1
1 1 1 (E2) Carbon black 1 1 1 1 1 1 Evaluation item Sheet-like
shape Favor- Failed Favor- Failed Failed Failed able to be able to
be to be to be Glass-transition 190 molded 220 molded molded molded
temperature[Tg](.degree. C.) into into into into Linear expansion
4.5 sheet-like 5.2 sheet-like sheet-like sheet-like
coefficient(ppm/.degree. C.) shape (NA) shape (NA) shape (NA) shape
(NA) Flow mark (Yes.cndot.No) No No Filling failure (Yes.cndot.No)
No No Warpage amount(mm) 5 12 Reliability test Presence or absence
NG NG of peeling, crack (IR reflow) Temperature cycle test 0 cycles
NG NG 250 cycles NG NG 500 cycles NG NG 750 cycles NG NG
Results
[0092] With regard to the phenol curing agent as the component (B),
larger amounts of warpage (mm) were confirmed when using the phenol
curing agent (B5) as a curing agent other than the resorcinol-type
phenolic resins (B1) to (B4) (comparative example 1). Further,
larger amounts of warpage (mm) were still confirmed as compared to
working examples 1 to 8, even after doubling the used amount of the
phenol curing agent (B5). With regard to the inorganic filler as
the component (D), the resin composition failed to be formed into a
sheet-like shape as a result of using D2 to D4 (comparative
examples 3, 6 and 7) and when high filling of D1 was performed
excessively (comparative example 5). Further, a smaller amount of
the inorganic filler added led to a larger amount of warpage and
the occurrence of peelings and cracks (comparative examples 4).
[0093] Based on the above results, the following were confirmed
with the resin composition of the invention. That is, the resin
composition of the invention has a high glass-transition
temperature, a high fluidity and a high heat resistance. Further,
the resin composition of the invention exhibits a small degree of
warpage and undergoes small degrees of expansion and contraction.
Furthermore, the resin composition of the invention is capable of
being formed into a sheet-like shape.
* * * * *