U.S. patent application number 11/898615 was filed with the patent office on 2008-03-20 for set of resin compositions for preparing system-in-package type semiconductor device.
This patent application is currently assigned to Shin-Etsu Chemical Co., Ltd.. Invention is credited to Kaoru Katoh, Taro Shimoda, Kazuaki Sumita.
Application Number | 20080070054 11/898615 |
Document ID | / |
Family ID | 39188972 |
Filed Date | 2008-03-20 |
United States Patent
Application |
20080070054 |
Kind Code |
A1 |
Sumita; Kazuaki ; et
al. |
March 20, 2008 |
Set of resin compositions for preparing system-in-package type
semiconductor device
Abstract
A set of compositions for preparing a system-in-package type
semiconductor device, characterized in that the set of compositions
consists of an underfill composition for preparing the underfill
part and an encapsulation resin composition for preparing the resin
encapsulation part, wherein 1) a cured product of the underfill
composition has a glass transition temperature, Tg, which is
100.degree. C. or higher and is the same with or differs from a Tg
of a cured product of the encapsulation resin composition by
20.degree. C. or smaller, 2) a total of a linear expansion
coefficient of the cured product of the underfill composition at a
temperature not higher than (Tg-30).degree. C. and a linear
expansion coefficient of the cured product of the encapsulation
resin composition at a temperature not higher than (Tg-30).degree.
C. is 42 ppm/.degree. C. or smaller, and 3) a ratio of the linear
expansion coefficient of the cured product of the encapsulation
resin composition to the linear expansion coefficient of the cured
product of the underfill composition ranges from 0.3 to 1.0.
Inventors: |
Sumita; Kazuaki;
(Annaka-shi, JP) ; Katoh; Kaoru; (Annaka-shi,
JP) ; Shimoda; Taro; (Annaka-shi, JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
Shin-Etsu Chemical Co.,
Ltd.
|
Family ID: |
39188972 |
Appl. No.: |
11/898615 |
Filed: |
September 13, 2007 |
Current U.S.
Class: |
428/500 ;
257/E21.503; 257/E23.119; 257/E25.013 |
Current CPC
Class: |
H01L 2924/00011
20130101; H01L 2224/32145 20130101; H01L 2224/73265 20130101; H01L
2224/48091 20130101; H01L 2224/48091 20130101; H01L 2924/10253
20130101; H01L 2224/73203 20130101; H01L 2224/73265 20130101; H01L
2924/10253 20130101; H01L 2224/48227 20130101; H01L 2924/00014
20130101; H01L 2924/00014 20130101; H01L 2224/32225 20130101; H01L
2924/15311 20130101; Y10T 428/31855 20150401; H01L 2225/06517
20130101; H01L 2225/0651 20130101; H01L 23/3128 20130101; H01L
2924/15311 20130101; H01L 2224/73265 20130101; H01L 2924/01012
20130101; H01L 21/563 20130101; H01L 2224/16225 20130101; H01L
2225/06575 20130101; H01L 2924/00014 20130101; H01L 2924/00014
20130101; H01L 2924/181 20130101; H01L 2224/73204 20130101; H01L
2924/15311 20130101; H01L 24/48 20130101; H01L 2225/06586 20130101;
H01L 2224/73265 20130101; H01L 2224/73204 20130101; H01L 2924/01077
20130101; H01L 2224/16225 20130101; H01L 2224/73204 20130101; H01L
2924/00 20130101; H01L 2224/16225 20130101; H01L 2224/0401
20130101; H01L 2224/48227 20130101; H01L 2224/45015 20130101; H01L
2224/45099 20130101; H01L 2924/00 20130101; H01L 2924/00 20130101;
H01L 2924/00014 20130101; H01L 2224/32145 20130101; H01L 2924/00
20130101; H01L 2224/32225 20130101; H01L 2224/73265 20130101; H01L
2224/32225 20130101; H01L 2224/48227 20130101; H01L 2224/0401
20130101; H01L 2224/32145 20130101; H01L 2224/32225 20130101; H01L
2224/32225 20130101; H01L 2924/207 20130101; H01L 2924/00012
20130101; H01L 2924/00 20130101; H01L 2224/48227 20130101; H01L
2924/00012 20130101; H01L 2224/48227 20130101; H01L 2924/00011
20130101; H01L 2225/06582 20130101; H01L 2924/01019 20130101; H01L
25/0657 20130101; H01L 2924/181 20130101; H01L 24/73 20130101; H01L
23/293 20130101; H01L 2924/01087 20130101 |
Class at
Publication: |
428/500 |
International
Class: |
B32B 27/38 20060101
B32B027/38; C08K 9/10 20060101 C08K009/10 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 14, 2006 |
JP |
2006-249802 |
Sep 7, 2007 |
JP |
2007-232555 |
Claims
1. A set of compositions for preparing a system-in-package type
semiconductor device, said system-in-package type semiconductor
device comprising a substrate, a first semiconductor element
flip-chip bonded to the substrate, an underfill part between the
first semiconductor element and the substrate, at least one second
semiconductor element placed on the first semiconductor element,
and a resin encapsulation part covering the first semiconductor
element, the underfill part and the second semiconductor element,
characterized in that the set of compositions consists of an
underfill composition for preparing the underfill part and an
encapsulation resin composition for preparing the resin
encapsulation part, wherein 1) a cured product of the underfill
composition has a glass transition temperature, Tg, which is
100.degree. C. or higher and is the same with or differs from a Tg
of a cured product of the encapsulation resin composition by
20.degree. C. or smaller, 2) a total of a linear expansion
coefficient of the cured product of the underfill composition at a
temperature not higher than (Tg-30).degree. C. and a linear
expansion coefficient of the cured product of the encapsulation
resin composition at a temperature not higher than (Tg-30).degree.
C. is 42 ppm/.degree. C. or smaller, and 3) a ratio of the linear
expansion coefficient of the cured product of the encapsulation
resin composition to the linear expansion coefficient of the cured
product of the underfill composition ranges from 0.3 to 1.0.
2. The set according to claim 1, wherein the underfill composition
comprises (A) an epoxy resin, (B) a curing agent in such an amount
that an equivalent ratio of the epoxy group in the component (A) to
a functional group in the component (B) ranges from 0.7 to 1.2,
said functional group being reactive with the epoxy group, and (C)
an inorganic filler in an amount of from 50 to 500 parts by weight
per 100 parts by weight of the component (A), and the encapsulating
resin composition comprises (a) a biphenyl aralkyl epoxy resin or
triphenyl epoxy resin, (b) a biphenyl aralkyl phenolic resin or
triphenyl phenolic resin in such an amount that an equivalent ratio
of the epoxy group in the component (a) to the phenolic hydroxyl
group in the component (b) ranges from 0.8 to 1.2, and (c) an
inorganic filler in an amount of from 500 to 1,100 parts by weight
per total 100 parts by weight of the components (a) and (b).
3. The set according to claim 2, wherein the curing agent (B) is an
amine curing agent or a peroxide curing agent.
4. The set according to claim 3, wherein the curing agent (B) is at
least one selected from the group consisting of the aromatic amine
compounds represented by the following formulas (1), (2), (3) and
(4), ##STR00019## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 may
be the same with or different from each other and are selected from
the group consisting of monovalent C.sub.1-6 hydrocarbon groups,
CH.sub.3S-- and C.sub.2H.sub.5S--.
5. The set according to claim 2, wherein the inorganic filler (C)
is a spherical silica which is produced by a sol-gel method or a
deflagration method and has an average particle size of from 0.1 to
5 .mu.m.
6. The set according to claim 2, wherein the component (A) is
selected from the group consisting of bisphenol-A epoxy resins,
bisphenol-F epoxy resins and the epoxy resins represented by the
following three formulas, ##STR00020## wherein R is a monovalent
hydrocarbon group having 1 to 20 carbon atoms and n is an integer
of from 1 to 4, and the component (a) is a biphenyl aralkyl epoxy
resin.
7. A system-in-package type semiconductor device, comprising a
substrate, a first semiconductor element flip-chip bonded to the
substrate, an underfill part between the first semiconductor
element and the substrate, at least one second semiconductor
element placed on the first semiconductor element, and a resin
encapsulation part covering the first semiconductor element, the
underfill part and the second semiconductor element, characterized
in that the underfill part and the encapsulation part are composed
of a cured products of the underfill composition and the
encapsulating resin composition, respectively, of the set according
to any one of claims 1 to 6.
Description
CROSS REFERENCES
[0001] This application claims benefit of Japanese Patent
Applications No. 2006-249802 filed on Sep. 14, 2006, and Japanese
Patent Applications No. 2007-232555 filed on Sep. 7, 2007, the
contents of which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to resin compositions suitable
for preparing a system-in-package type semiconductor device.
Specifically, the present invention relates to a set of resin
compositions consisting of an underfill resin composition and
encapsulating resin composition. The compositions in combination
provide a semiconductor device which is strongly adhered to a
substrate and has a high resistance to heat and thermal shock.
BACKGROUND OF THE INVENTION
[0003] Associated with downsizing, lightening, and
functionalization of electronic devices, packaging of a
semiconductor device is mainly performed by surface mounting method
rather than pin insertion method. Recently, the
system-in-packaging, hereinafter referred to as SIP, is widely used
in which a plurality of silicon dies is packaged in one package.
Particularly, a stack type SIP is used in which at least one
semiconductor chip is stacked and wire bonded on another
semiconductor chip.
[0004] FIG. 1 is a cross-sectional view of a semiconductor device,
in which a semiconductor chip 3 is flip-chip bonded via solder
bumps 2 on a surface of a substrate 1 provided with electronic
circuits. The gaps between the substrate 1 and the semiconductor
chip 3, i.e., spaces between the solder bumps, are filled with an
underfill composition 4. FIGS. 2 and 3 show cross-sectional views
of system-in-package type semiconductor devices in which one or
more of-semiconductor chip is placed on a semiconductor chip
flip-chip bonded to the substrate 1.
[0005] SIP semiconductor devices are required to show no peeling or
crack at an interface between an underfill part and a silicon chip
or a substrate during a reflow process and a mounting process. In
addition, the underfill part must supplement weaker adhesion of a
lead-free solder than that of conventional solder.
[0006] As resin materials to avoid such peeling or crack, the
Japanese Patent Application Laid-Open No. H9-176287 and H9-176294
describe resin compositions comprising a liquid epoxy resin and an
alkyl-substituted aromatic amine. It is described that these
compositions form cured products strongly adhered to a substrate,
metal and solder resist, and give a highly reliable semiconductor
package having high reflow- and thermal cycle-resistances. However,
when the cured products of these resin compositions are
encapsulated with a resin, they were found to crack or peel
depending on the encapsulation resin used.
SUMMARY OF THE INVENTION
[0007] An object of the present invention is therefore to provide a
set of an underfill composition and an encapsulation resin
composition which provides semiconductor device packages resistant
to heat and thermal shock.
[0008] The present invention is a set of compositions for preparing
a system-in-package type semiconductor device, said
system-in-package type semiconductor device comprising
[0009] a substrate,
[0010] a first semiconductor element flip-chip bonded to the
substrate,
[0011] an underfill part between the first semiconductor element
and the substrate,
[0012] at least one second semiconductor element placed on the
first semiconductor element, and
[0013] a resin encapsulation part covering the first semiconductor
element, the underfill part and the second semiconductor
element,
[0014] characterized in that the set of compositions consists of an
underfill composition for preparing the underfill part and an
encapsulation resin composition for preparing the resin
encapsulation part, wherein
[0015] 1) a cured product of the underfill composition has a glass
transition temperature, Tg, which is 100.degree. C. or higher and
is the same with or differs from a Tg of a cured product of the
encapsulation resin composition by 20.degree. C. or smaller,
[0016] 2) a total of a linear expansion coefficient of the cured
product of the underfill composition at a temperature not higher
than (Tg-30).degree. C. and a linear expansion coefficient of the
cured product of the encapsulation resin composition at a
temperature not higher than (Tg-30).degree. C. is 42 ppm/.degree.
C. or smaller, and
[0017] 3) a ratio of the linear expansion coefficient of the cured
product of the encapsulation resin composition to the linear
expansion coefficient of the cured product of the underfill
composition ranges from 0.3 to 1.0.
[0018] Because of the specific combination of glass transition
temperatures and linear expansion coefficients, no crack or
separation occurs between curing products of the compositions or
the curing product and substrate when they are exposed to thermal
shock such as reflow process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a cross-sectional view of an example of a
flip-chip type semiconductor device;
[0020] FIG. 2 is a cross-sectional view of an example of a
system-in-package type semiconductor device; and
[0021] FIG. 3 is a cross-sectional vies of another example of a
system-in-package type semiconductor device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Firstly, the limitations from 1) to 3) are explained. The
limitation 1) is a relationship between a glass transition
temperature, hereinafter referred to as Tg, of a curing product of
the underfill composition and that of a curing product of the
encapsulating resin composition. The Tg can be determined by a
known method such as the thermomechanical analysis (TMA) and
Theological measurements. The Tg of the cured product of the
underfill composition is higher than 100.degree. C., preferably
higher than 120.degree. C. A cured product having Tg below
100.degree. C. may be peeled off from a substrate during a reflow
process due to a lower adhesion to the substrate. An upper limit of
Tg is practically about 200.degree. C. In addition, the Tg of the
cured product of the underfill composition is the same with or
differs from Tg of the cured product of the encapsulating resin
composition by 20.degree. C. or smaller. If the difference between
the Tg's are greater than 20.degree. C., stresses between the
underfill part and encapsulation part will be so large that an
interface between both parts or between the underfill or
encapsulation part and a passivation layer of a substrate may
peel.
[0023] The limitations 2) and 3) are relationships between linear
expansion coefficients of the cured products of the both
compositions. A linear expansion coefficient can be determined by
the thermomechanical analysis (TMA). A linear expansion coefficient
at a temperature of (Tg-30).degree. C. is substantially constant at
any temperature not higher than (Tg-30).degree. C. In the present
invention, it was determined from TMA data at a temperature range
of from 50 to 80.degree. C. A total of linear expansion
coefficients at a temperature of (Tg-30).degree. C. of a cured
product of the underfill composition and that of a cured product of
the encapsulation resin composition is 42 ppm/.degree. C. or
smaller, preferably 40 ppm/.degree. C. or smaller. If the total
exceeds 42 ppm/.degree. C., peeling or crack may occur at an
interface between an underfill part and a resin encapsulation part
or between the underfill and a passivation layer.
[0024] In addition, a ratio of the linear expansion coefficient at
a temperature of (Tg-30).degree. C. of a cured product of the
underfill composition to that of a cured product of the
encapsulation resin composition ranges from 0.3 to 1.0, preferably
from 0.3 to 0.9. If the ratio is outside the aforesaid range, a
crack or peeling may occur between an underfill part and a resin
encapsulation part.
[0025] Preferably, the underfill composition comprises
[0026] (A) an epoxy resin,
[0027] (B) a curing agent in such an amount that an equivalent
ratio of the epoxy group in the component (A) to a functional group
in the component (B) ranges from 0.7 to 1.2, said functional group
being reactive with the epoxy group, and
[0028] (C) an inorganic filler in an amount of from 50 to 500 parts
by weight per 100 parts by weight of the component (A).
[0029] (A) Epoxy Resin
[0030] Preferred examples of the epoxy resin (A) used in the
present invention include bisphenol type epoxy resins such as
bisphenol F type epoxy resins and bisphenol A type epoxy resins;
novolac type epoxy resins such as phenol novolac type epoxy resins
and cresol novolac type epoxy resins; naphthalene ring-containing
epoxy resins, biphenyl type epoxy resins, cyclopentadiene type
epoxy resins, and a mixture of two or more of these epoxy resins.
Among these, bisphenol A type epoxy resins and bisphenol F type
epoxy resins are preferred.
[0031] The epoxy resins represented by the following formulas are
also preferred.
##STR00001##
[0032] In the formula (5), R is a monovalent hydrocarbon group
having 1 to 20, preferably 1 to 10, more preferably 1 to 3, carbon
atoms. Examples of R include alkyl groups such as methyl, ethyl and
propyl groups and alkenyl groups such as vinyl and allyl groups; n
is an integer of from 1 to 4, particularly 1 or 2.
[0033] When the epoxy resin of the aforesaid formula (5) is used,
its content in the whole epoxy resin (A) ranges from 25 to 100 wt
%, preferably from 50 to 100 wt %, more preferably from 75 to 100
wt %. If it is contained in an amount less than the aforesaid lower
limit, a viscosity of such a composition is undesirably high and
heat resistance of a cured product may be low. Example of the epoxy
resin of the formula (5) is the one sold under the trade name of
MRGE from Nihon Kayaku Co.Ltd.
[0034] (B) Curing Agent
[0035] Examples of the curing agent (B) include amine type,
polymercaptane type, imidazol type, acid anhydride type and
dicyanodiamide type curing agents. Preferably, amine type and acid
anhydride type curing agents are used. Preferred amine curing agent
are represented by the following formulas (1) to (4),
##STR00002##
[0036] wherein R.sup.1 to R.sup.4 may be the same with or different
from each other and are selected from the group consisting of
monovalent hydrocarbon groups having 1 to 6 carbon atoms,
CH.sub.3S-- and C.sub.2H.sub.5S--.
[0037] Preferred examples of monovalent hydrocarbon groups include
alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl,
isobutyl, tert-butyl, and hexyl; alkenyl groups such as vinyl,
allyl, propenyl, butenyl, and hexenyl groups; phenyl group; and
halogenated groups thereof such as fluoromethyl, bromoethyl, and
3,3,3-trifluoropropyl groups, among which those having 1 to 3
carbon atoms are preferred.
[0038] Aforesaid aromatic amine curing agents are mostly solid at
room temperature, so that they tend to thicken the epoxy resin when
they are mixed with the epoxy resin as they are. It is therefore
preferred to melt-mix the amine curing agent with the epoxy resin
at a temperature low enough to avoid reaction with the epoxy resin.
That is, the aromatic amine curing agent is preferably melt-mixed
at a temperature of from 70 to 150.degree. C. for 1 to 2 hours with
the epoxy resin. At a temperature below 70.degree. C., the aromatic
amine curing agent may not melt sufficiently, whereas at a
temperature above 150.degree. C. it tends to react with the epoxy
resin to thicken the composition. A period of mixing time shorter
than 1 hour may not enough to thoroughly mix the aromatic amine
curing agent with epoxy resin, whereas more than 2 hours may cause
reaction with the epoxy resin.
[0039] Examples of the acid anhydride curing agent include
methyltetrahydrophthalic anhydride, methylhexahydrophthalic
anhydride, hexahydrophthalic anhydride, methylhimic acid anhydride,
pyromellitic acid dianhydride, allo-ocimene maleate, benzophenone
tetracarboxylic acid anhydride,
3,3',4,4'-biphenyltetrabisbenzophenone tetracarboxylic acid
anhydride, (3,4-dicarboxyphenyl) ether dianhydride,
bis(3,4-dicaroxyphenyl)methane dianhydride,
2,2-bis(3,4-dicarboxyphenyl)propane dianhydride,
3,4-dimethyl-6-(2-methyl-1-propenyl)-1,2,3,6-tetrahydrophthalic
acid anhydride,
1-isopropyl-4-methyl-bicyclo[2.2.2]octo-5-ene-2,3-dicaroxylic acid
anhydride and a mixture thereof. Preferred curing agents are
methyltetrahydrophthalic anhydride, methylhexahydrophthalic
anhydride, hexahydrophthalic anhydride,
3,4-dimethyl-6-(2-methyl-1-propenyl)-1,2,3,6-tetrahydrophthalic
acid anhydride,
1-isopropyl-4-methyl-bicyclo[2.2.2]octo-5-ene-2,3-dicaroxylic acid
anhydride and a mixture thereof. These acid anhydrides are sold
under the trade names of Rikacid MH700 from New Japan Chemical co.,
ltd., YH306 and YH307 both from Japan Epoxy Resin Co.
[0040] The curing agent (B) is contained in the composition in such
an amount that an equivalent ratio of its epoxy-reactive functional
group to the epoxy group-of the epoxy resin (A) of from 0.7 to 1.2,
preferably from 0.8 to 1.0. If it is contained less than the
aforesaid lower limit, a part of the epoxy resin remains unreacted,
resulting in lower glass transition temperature and smaller
adhesion to a substrate. If it is contained above the aforesaid
upper limit, a cured product may be so hard and brittle that it
cracks in a reflow process or a heat cycle test.
[0041] (C) Inorganic Filler
[0042] As the inorganic filler, any known inorganic filler can be
used. Examples of the inorganic filler include fused silica,
crystalline silica, alumina, boron nitride, aluminum nitride,
silicon nitride, magnesia, magnesium silicate, and aluminum. Among
these, spherical fused silica is preferred because it gives a
composition having a desirable low viscosity of a composition. More
preferred is fused silica prepared by sol-gel method or
deflagration method.
[0043] Preferably, the inorganic filler is surface treated in
advance with a coupling agent such as a silane coupling agent or
titanate coupling agent to strengthen adhesion between the filler
and resins. Preferred coupling agents are silane coupling agents,
for example, epoxy silanes such as
.gamma.-glycidoxypropyltrimethoxysilane,
.gamma.-glycidoxypropylmethyldiethoxysilane, and
.beta.-(3,4-epoxycyclohexyl)ethyl trimethoxysilane; aminosilanes
such as N-.beta.(aminoethyl)-.gamma.-aminopropyltrimethoxysilane,
.gamma.-aminopropyltriethoxysilane, and
N-phenyl-.gamma.-aminopropyltrimethoxysilane; and mercaptosilane
such as .gamma.-mercaptosilane. An amount of the silane coupling
agent and a method of surface treatment to be used are not limited
to particular ones.
[0044] A particle size of the inorganic filler is preferably
selected according to a gap size of a semiconductor device, i.e., a
distance between a substrate and a semiconductor chip. For a
typical device having a gap size ranging from 10 to 200 .mu.m, an
average particle size ranges from 0.1 to 5 .mu.m, preferably from
0.5 to 2 .mu.m because a underfill composition comprising such
inorganic filler has a desired viscosity and gives a cured product
having a desired linear expansion coefficient. A composition
containing an inorganic filler having a particle size smaller than
the aforesaid lower limit may have a viscosity too high to
penetrate smoothly in a gap. On the other hand, an inorganic filler
having a particle size larger than the aforesaid upper limit may
plug the gap to cause a void in a cured product.
[0045] The inorganic filler preferably has such a particle size
distribution that a fraction of particles having a particle size of
one half the gap size or larger is not more than 0.1 wt %,
particularly from 0 to 0.8 wt %, of the whole particles.
Preferably, the inorganic filler has an average particle size,
i.e., a median size(d.sub.50), of about one-tenth of the gap size
or smaller, and a maximum particle size, i.e., a particle size at
98 volume % in a cumulative particle size distribution (d.sub.98),
of one half the gap size of smaller. A particle size and its
distribution can be measured by a laser diffraction method, for
example. An amount of the inorganic filler having a particle size
larger than one half the gap size can be determined by i) mixing
the inorganic filler with pure water in a weight ratio of 1:9, ii)
ultrasonicating the mixture to break up flocculants, iii) filtering
the mixture with a sieve having a mesh size of one half the gap
size, and iv) weighing a residue left on the sieve.
[0046] It was found that a sol-gel method and a deflagration method
are most suitable for producing particles having the aforesaid
particle size and its distribution. Spherical silica made by these
methods has a spherical form and a controlled particle size
distribution. The sol-gel method and the deflagration are well
known in the art and is not explained here.
[0047] Preferably, 80 wt % or more, more preferably 90 to 100 wt %,
most preferably 95 to 100 wt % of the inorganic filler is the
spherical silica made by the sol-gel method or the deflagration
method. If a ratio of the spherical silica is less than the
aforesaid lower limit, a fluidity or spreadability of a composition
may not be good.
[0048] The inorganic filler (C) is contained in the underfill
composition in an amount of from 50 to 500 parts by weight,
preferably from 100 to 400 parts by weight, per 100 parts by weight
of the epoxy resin (A). A composition containing the inorganic
filler less than the aforesaid lower limit may give a cured product
having a large linear expansion coefficient, whereas a composition
containing the inorganic filler larger than the aforesaid upper
limit may be too viscous to smoothly penetrate in the gap.
[0049] Optional Components
[0050] The underfill composition of the present invention can
contain an optional component in an amount not to adversely affect
the composition. Examples of the optional components include resins
to provide a cured composition with flexibility, for example,
silicone-modified epoxy resin, silicone rubber, silicone oil,
liquid polybutadiene rubber, and methyl
methacrylate-butadiene-styrene copolymer; silane coupling agents;
pigments such as carbon black; dyes, and antioxidants.
[0051] Preferably, the silicone-modified epoxy resin is a copolymer
prepared by addition-reacting an epoxy resin or a phenolic resin
having an alkenyl group with an organopolysiloxane represented by
the following average compositional formula (6)
H.sub.aR.sup.5.sub.bSiO.sub.(4-a-b) (6)
[0052] wherein R.sup.5 is a substituted or unsubstituted monovalent
hydrocarbon group, a is a number of from 0.01 to 0.1, b is a number
of from 1.8 to 2.2 with a+b ranging from 1.81 to 2.3, which has 20
to 400 silicon atoms, and 1 to 5, preferably 2 to 4, particularly 2
SiH bonds.
[0053] Preferred examples of R.sup.5include monovalent hydrocarbon
group having 1 to 10, particularly 1 to 8, carbon atoms, for
example, alkyl groups such as methyl, ethyl, propyl, isopropyl,
butyl, isobutyl, tert-butyl, hexyl, octyl, and decyl groups;
alkenyl groups such as vinyl, allyl, propenyl, butenyl and hexenyl
groups; aryl groups such as phenyl, xylyl and tolyl groups; aralkyl
groups such as benzyl, phenylethyl, and phenylpropyl groups, and
halogenated groups thereof such as chloromethyl, bromoethyl, and
trifluoropropyl groups.
[0054] Preferably, the copolymer is represented by the following
formula (7).
##STR00003##
[0055] In the formula (7), R.sup.5 is as defined above, R.sup.6 is
--CH.sub.2CH.sub.2CH.sub.2--,
--OCH.sub.2--CH(OH)--CH.sub.2--O--CH.sub.2CH.sub.2CH.sub.2, or
--O--CH.sub.2CH.sub.2CH.sub.2--, R.sup.7 is a hydrogen atom or an
alkyl group having 1 to 4 carbon atoms, n is an integer of from 4
to 199, preferably from 19 to 109, p is an integer of from 1 to 10,
and q is an integer of 1 to 10.
[0056] The silicone-modified epoxy resin is incorporated in the
composition in such an amount that a content of the
diorganosiloxane units preferably ranges from 1 to 20 parts by
weight, particularly from 2 to 15 parts by weight, per 100 parts by
weight of the epoxy resin (A). The silicone-modified epoxy resin
can decrease stress incurred on a cured product and increase
adhesion strength to a substrate. The content of the
diorganosiloxane units is calculated by the following equation:
[0057] A content of diorganosiloxane units=(a molecular weight of
the diorganosiloxane moiety/a molecular weight of the
silicone-modified epoxy resin).times.content of the
silicone-modified epoxy resin
[0058] Preparation of the Underfill Composition
[0059] The underfill composition can by prepared by mixing the
aforesaid components (A) to (C) and optional components, if
desired, altogether or sequentially while heating, if necessary.
Any mixing apparatus can be used such as an automatic mortar
equipped with a heater, a three-roll mill, a ball mill, and a
planetary mixer.
[0060] The underfill composition preferably has a viscosity at
25.degree. C. of from 1 to 500 Pas, particularly from 1 to 150 Pas.
The underfill composition is cured in an oven preferably by heating
first at a temperature of from 100 to 120.degree. C. for 0.5 hour
or longer and then at a temperature of from 150 to 170.degree. C.
for 0.5 hour or longer. If the former heating is performed shorter
than 0.5 hour, a final cured product may have a void. If the latter
heating is performed shorter than 0.5 hour, a final cured product
may not have satisfactory mechanical properties.
[0061] Now, the encapsulation resin composition of the present
invention is explained. The encapsulation resin composition
comprises
[0062] (a) a biphenyl aralkyl epoxy resin or triphenyl epoxy
resin,
[0063] (b) a biphenyl aralkyl phenolic resin or triphenyl phenolic
resin in such an amount that an equivalent ratio of the epoxy group
in the component (a) to the phenolic hydroxyl group in the
component (b) ranges from 0.8 to 1.2, and
[0064] (c) an inorganic filler in an amount of from 500 to 1,100
parts by weight per total 100 parts by weight of the components (a)
and (b).
[0065] (a) A biphenyl aralkyl Epoxy Resin or triphenyl Epoxy
Resin
[0066] An example of the biphenyl aralkyl epoxy resin is
represented by the following formula
##STR00004##
[0067] wherein R.sup.1 is an alkyl group having 1 to 4 carbon atoms
such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl and
tert-butyl groups, among which methyl group is preferred; a is an
integer of from 0 to 4, b is an integer of from 0 to 3, and Q is an
integer of from 0 to 10. A cured product of the biphenyl aralkyl
epoxy resin is flexible with a low modulus of elasticity and is
impact-resistant.
[0068] Examples of the biphenyl aralkyl epoxy resin represented by
the above formula are as shown below,
##STR00005##
[0069] wherein p is a number of from 0.5 to 1.5.
[0070] An example of the triphenyl epoxy resin is represented by
the following formula,
##STR00006##
[0071] wherein Gr represents a glycidyl group. This resin gives a
cured product highly resistant to heat.
[0072] The encapsulation resin composition can comprise other type
of epoxy resins, for example, novolac type epoxy resins, cresol
novolac type epoxy resins, triphenol alkane type epoxy resins,
heterocyclic epoxy resins, naphthalene ring-containing epoxy
resins, bisphenol-A type epoxy resins, bisphenol-F type epoxy
resins, stilbene type epoxy resins, and a mixture thereof. Among
these, those having a low melt viscosity are preferred such as
bisphenol-A type epoxy resins, bisphenol-F type epoxy resins, and
stilbene type epoxy resins. When the other type of epoxy resin is
incorporated in the composition, the aforesaid aralkyl epoxy resin
or triphenyl epoxy resin preferably dominates the component (a) in
an amount of from 50 to 100 wt %, more preferably from 70 to 100 wt
% of the component (a).
[0073] (b) A biphenyl aralkyl phenolic Resin or triphenyl phenolic
Resin
[0074] A preferred biphenyl aralkyl phenolic resin is represented
by the following formula because the resin gives a heat- and
crack-resistant cured product.
##STR00007##
[0075] In the above formula, R.sup.2 is an C.sub.1-4 alkyl group
such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl and
tert-butyl groups, or a phenyl group, among which methyl and phenyl
groups are preferred; a is an integer of from 0 to 4; b is an
integer of from 0 to 3; and Q is an integer of from 0 to 10.
[0076] Examples of the phenol resin represented by the above
formula are as shown below,
##STR00008##
[0077] wherein m is a number of from 0.5 to 1.5 on average.
[0078] The triphenol resin is represented by the following
formula,
##STR00009##
[0079] wherein R is a hydrogen atom or C.sub.1-4 alkyl group such
as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, or tert-butyl
group.
[0080] The triphenol type resin is resistant to heat and has a
relatively low viscosity, so that it enables one to formulate a
composition which forms a cured product having high glass
transition temperature and contains a larger amount of filler. An
example of the triphenol resin of the above formula is as shown
below.
##STR00010##
[0081] The component (b) can contain other types of phenolic
resins, for example, phenol novolac type resins, naphthalene
ring-containing phenolic resins, phenol aralkyl type phenolic
resins, biphenyl type phenolic resins, alicyclic phenolic resins,
heterocyclic phenolic resins, bisphenol-A type phenolic resins, and
bisphenol-F type phenolic resins. When the other phenolic resin is
contained in the composition, it is contained in an amount
preferably not more than 50 wt %, more preferably not more than 70
wt %.
[0082] The component (b) is contained in the composition in such an
amount that an equivalent ratio of the epoxy group in the component
(a) to the phenolic hydroxyl group in the component (b) ranges from
0.8 to 1.2. A composition containing the component (a) more than
the aforesaid lower upper limit may not be cured well whereas a
composition containing the component (a) less than the aforesaid
lower limit may form a cured product having worse moisture
resistance.
[0083] (c) Inorganic Filler
[0084] As the inorganic filler (c), commonly used inorganic filler
can be used. Examples of the inorganic filler include silica such
as spherical fused silica, crushed fused silica, and crystalline
silica, alumina, mullite, silicon nitride, aluminum nitride, boron
nitride, titanium oxide, and glass fiber. Among these, silica,
particularly, spherical fused silica is preferred. More preferably,
the spherical fused silica has an average particle size ranging
from 5 to 30 .mu.m and a weight fraction of particles having a
particle size larger than 75 .mu.m, as measured by wet screening
method, is not more than 0.2 wt % because such spherical fused
silica gives a composition having good molding property and
fluidity.
[0085] The component (c) is contained in the composition in an
amount of from 500 to 1,100 parts by weight per total 100 parts by
weight of the components (a) and (b). Less than the aforesaid lower
limit of the component (c) gives a larger linear expansion
coefficient of a cured composition, causing a semiconductor device
to warp. A composition comprising component (c) in an amount more
than the aforesaid upper limit may have a viscosity too high to be
molded.
[0086] Preferably, the inorganic filler is surface treated in
advance with a silane coupling agent such as an aminosilane or an
epoxy silane. An amount and a method of surface treatment are not
limited to particular ones.
[0087] The encapsulation resin composition can contain an optional
component in an amount not to adversely affect the composition.
Examples of the optional components include resins to provide a
cured composition with flexibility such as thermoplastic resins,
thermoplastic elastomers, synthetic organic rubbers, and silicones;
release agents such as carnauba wax, colorants such as carbon
black; flame retardants such as halogenated resins, antimony oxide,
and molybdate; and halogen trapping agents.
[0088] The encapsulation resin composition can be prepared by (i)
thorouglhly mixing the components (a) to (c), and an optional
component, if desired, with a mixer such as a Henschel mixer, (ii)
melt-kneading the mixture with a heated roll, kneader, or an
extruder, (iii) cooling the molten mixture to solidify, and (iv)
pulverizing the solidified mixture. In the step (i), a silane
coupling agent may be added to the mixture to promote wetting the
inorganic filler. The silane coupling agent described above can be
used.
EXAMPLES
[0089] The present invention will be further explained with
reference to the following Examples, but shall not be limited
thereto.
[0090] Preparation of Underfill Compositions
[0091] Twelve underfill compositions, UF-1 to UF-12, were prepared
by kneading the components with a three-roller mill according to
the formulations shown in the Table 1. The substances indicated in
the Table 1 are as follows.
[0092] (A) Epoxy Resin
[0093] Epoxy resin A1: Tri-functional epoxy resin represented by
the following formula, EPIKOTE 630H, ex Japan Epoxy Resin Co.,
Ltd.
##STR00011##
[0094] Epoxy resin A2: Bisphenol-F epoxy resin represented by the
following formula, RE303S-L, ex Nihon Kayaku Co., Ltd.
##STR00012##
[0095] (B) Curing Agent
[0096] Curing agent B1: 3,3'-diethyl-4,4'-diaminodiphenylmethane,
Kayahard AA, ex Nihon Kayaku Co., Ltd.
[0097] Curing agent B2:
3,3',5,5'-tetraethyl-4,4'-diaminodiphenylmethane, C-300S, ex Nihon
Kayaku Co., Ltd.
[0098] Curing agent B3: allo-ocimene maleate, a mixture of
3,4-dimethyl-6-(2-methyl-1-propenyl)-1,2,3,6-tetrahydrophthalic
acid anhydride and
1-isopropyl-4-methyl-bicyclo[2.2.2]octo-5-ene-2,3-dicarboxylic acid
anhydride, YH307, ex Japan Epoxy Resin Co., Ltd.
##STR00013##
[0099] Curing agent B4: a mixture of hexahydrophthalic anhydride,
Rikacid MH700, ex New Japan Chemical co., ltd.
##STR00014##
[0100] (C) Inorganic
[0101] Filler
[0102] Spherical silica: Spherical silica produced by deflagration
method which has an average particle size of 2.5 .mu.m with a
fraction of particles having a particle size of 25 .mu.m or larger
of 0.01 wt %, as determined by the following method.
[0103] A Method of Particle Size Analysis of Silica
[0104] A certain amount of silica was mixed with pure water with a
1:9 weight ratio, which was then ultrasonicated. The dispersion
obtained was screened with a filter-1 having a mesh of 25 .mu.m and
then a filer-2 having a mesh size of 10 .mu.m. The residues in wt %
of each screening were weighed. The analysis was repeated 5 times
and the results were averaged.
[0105] Additives
[0106] Silane coupling agent:
.gamma.-glycidoxypropyltrimethoxysilane, KBM403, ex Shin-Etsu
Chemical Co., Ltd.
[0107] Solvent: polyethyleneglycol methyl ethyl acetate, PGMEA,
having a boiling point of 146.degree. C.
[0108] Curing catalyst: 2-ethyl-4-methyl imidazol, ex Shikoku
Chemical, Co.
[0109] The compositions obtained were evaluated according to the
following methods.
[0110] (1) Viscosity
[0111] Viscosity of each composition was measured according to the
Japanese Industrial Standards (JIS) Z-8803 at 25.degree. C. with an
E-type viscometer. The reading was made two minutes after placing
the composition in the cone.
[0112] (2) Glass Transition Temperature (Tg), Linear Expansion
Coefficient at (Tg-30).degree. C. (CTE1), and Linear Expansion
Coefficient at a Temperature Higher than Tg(CTE2)
[0113] A cured product was prepared by heating a composition from
room temperature at a temperature increase rate of 10.degree.
C./min to a temperature of from 200 to 260.degree. C. and keeping
the temperature for a period of time of from 30 seconds to 5
minutes. The cured product obtained was cooled to room temperature
from which a 5 mm.times.5 mm.times.15 mm test piece was cut out.
The test piece was subjected to thermomechanical analysis(TMA) to
determine Tg, CTE1 and CTE2 with a temperature increase rate of
5.degree. C./min. When (Tg-30).degree. C. of the test piece was
found to be lower than 100.degree. C., CTE1 was determined from TMA
data of from -30 to 0.degree. C., and CTE2 was determined from TMA
data of from 150 to 180.degree. C. When (Tg-30).degree. C. of the
test piece was found to be 100.degree. C. or higher, CTE1 was
determined from TMA data of from 50 to 80.degree. C. and CTE2 was
determined from TMA data of from 200 to 230.degree. C.
[0114] (3) Void
[0115] A certain amount of a composition was penetrated in about 50
.mu.m-gap between a 30 mm.times.30 mm FR-4 substrate and a
flip-chip bonded silicon chip coated with a polyimide, and then
heated at 165.degree. C. for 30 minutes. The underfill thus
prepared was observed for voids with a scanning acoustic
microscope, C-SAM, ex SONIX K. K.
[0116] (4) Adhesion Strength
[0117] A certain amount of a composition was poured in a
polytetrafluoroethylene mold in the form of a truncated cone with a
bottom surface diameter of 2 mm, a top opening diameter of 5 mm,
and a height of 3 mm. On the top surface of the composition a
silicon chip coated with polyimide was placed, which then was
heated at 150.degree. C. for 3 hours to cure the composition. By
removing the mold from the cured composition, a test piece was
obtained. Initial adhesion strength was measured by pushing at a
speed of 1 mm/sec a side surface of the cured composition in the
form of truncated cone on the silicon chip. Adhesion strength after
pressure cooker test was measured in the same manner as above on a
test piece which had been kept in a pressure cooker tester at
121.degree. C. and 2.1 atm for 336 hours. Both adhesion strengths
were measured on five test pieces, respectively, and results were
averaged.
[0118] (5) Fracture Toughness (K.sub.1c)
[0119] A composition was cured at 150.degree. C. for 3 hours.
Fracture toughness at room temperature of the cured product was
measured according to
TABLE-US-00001 TABLE 1 Component, parts by weight UF-1 UF-2 UF-3
UF-4 UF-5 UF-6 UF-7 UF-8 UF-9 UF-10 UF-11 UF-12 (A) Epoxy resin A1
20 29 58 44 44 19 19 44 44 44 44 Epoxy resin A2 69 46 29 19 19 19
19 19 19 19 19 (B) Curing agent B1 14 16 20 20 Curing agent B2 14
16 20 20 35 35 35 35 35 35 Curing agent B3 30 30 Curing agent B4 30
30 (C) Inorganic filler 150 150 150 150 150 250 150 200 100 200 250
350 Others Silane coupling agent 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0
2.0 2.0 2.0 2.0 Solvent 3 3 3 3 3 3 3 3 3 3 Curing promoter 1 1
Equivalent ratio of 0.80 0.80 0.80 0.80 0.80 0.80 1.00 1.00 0.80
0.80 0.80 0.80 (A)/(B) Weight ratio of (C) 0.60 0.59 0.59 0.59 0.59
0.71 0.60 0.66 0.49 0.66 0.71 0.77 Results Viscosity Pa s@ 15.9
13.1 10.6 7.7 5.9 18.9 28.4 28.4 5.8 25.4 68 150 25.degree. C. Void
None None None None None None None None None None None None
Fracture MPam.sup.1/2 2.4 2.2 2.2 2.2 2.2 2.2 1.3 1.3 2.3 2.2 2.3
2.2 toughness, K.sub.1c Tg .degree. C. 95 110 125 160 137 136 140
137 137 137 137 137 CTE1 ppm/.degree. C. 29 29 29 29 28 27 29 25 42
28 24 17 CTE2 ppm/.degree. C. 107 105 102 103 106 91 113 100 121 90
72 64 Adhesion Initial 197 210 210 207 221 203 185 186 234 234 229
231 strength, After 185 180 186 196 195 196 96 83 200 196 184 189
MPa PCT336hr
[0120] Preparation of Encapsulation Resin Compositions
[0121] Six encapsulation resin compositions, EMC-1 to EMC-6, were
prepared by kneading the components with a three-roller mill
according to the formulations shown in the Table 2. The substances
indicated in the Table 2 are as follows.
[0122] (a) Epoxy Resin
[0123] Epoxy resin a1: a biphenyl aralkyl epoxy resin of the
following formula, NC-3000, ex Nihon Kayaku Co., Ltd.
##STR00015##
[0124] Epoxy resin a2: a tri-functional epoxy resin of the
following formula, EPPN-501H, ex Nihon Kayaku Co., Ltd.
##STR00016##
[0125] (b) Phenolic Resin
[0126] Phenolic resin b1: a tri-functional phenolic resin of the
following formula, MEH-7500, Meiwa Plastic Industries, Ltd.
##STR00017##
[0127] Phenolic resin b2: a biphenyl aralkyl phenolic resin of the
following formula, MEH-7851, Meiwa Plastic Industries, Ltd.
##STR00018##
[0128] (c) Inorganic Filler
[0129] Spherical silica: Spherical silica produced by deflagration
method which has an average particle size of 2.5 .mu.m with a
fraction of particles having a particle size of 25 .mu.m or larger
of 0.01 wt % as determined by the aforesaid method of particle size
analysis.
[0130] Additives
[0131] Curing promoter: Triphenylphosphine, ex Hokko Chemical
Industry Co., Ltd.
[0132] Silane coupling agent:
.gamma.-glycidoxypropyltrimethoxysilane, KBM403, ex Shin-Etsu
Chemical Co., Ltd.
[0133] Carbon black, Denki Kagaku Kogyo Kabushiki Kaisha
[0134] Releasing agent: Carnauba wax, Nikko Fine Products Co.
[0135] The compositions obtained were evaluated according to the
following methods.
[0136] (1) Spiral Flow
[0137] Using a mold according to Epoxy Molding Materials Institute
(E.M.M.I) standard, a spiral flow was measured at 175.degree. C.
and at a pressure of 6.9 N/mm.sup.2.
[0138] (2) Melt Viscosity
[0139] Using a Koka-shiki type flow tester equipped with a nozzle
having a diameter of 1 mm, a melt viscosity was measured at
175.degree. C. and at a pressure of 10 kgf.
[0140] (3) Glass Transition Temperature (Tg), Linear Expansion
Coefficient at (Tg-30).degree. C. (CTE1), Linear Expansion
Coefficient at a Temperature Higher than Tg(CTE2)
[0141] A cured product was obtained by heating a composition at
180.degree. C. for 24 hours. Tg, CTE1 and CTE2 of the cured product
were determined in the same manner as described above.
[0142] (4) Gel Time
[0143] A certain amount of a composition was spread on a hot plate
heated at 175.degree. C. and stirred with a spatula. A time
required for the composition to be released from the hot plate was
determined to be a gel time.
[0144] (5) Fracture Toughness (K.sub.1c)
[0145] A composition was molded at 175.degree. C. and at 6.9
N/mm.sup.2 for 90 seconds and post-cured at 180.degree. C. for 4
hours. Fracture toughness at room temperature of the cured product
was measured according to ASTM #D5045.
[0146] (6) Bending Strength and Modulus of Elasticity
[0147] A composition was mold at 175.degree. C. and at 6.9
N/mm.sup.2 for 90 seconds and post-cured at 180.degree. C. for 4
hours. According to JIS #K6911, bending strength and modulus of
elasticity at room temperature of the cured product were
measured.
[0148] (7) Specific Gravity
[0149] A composition was mold at 175.degree. C. and at 6.9
N/mm.sup.2 for 90 seconds and post-cured at 180.degree. C. for 4
hours. A specific gravity at room temperature of the cured product
obtained was measured according to JIS #K6911.
TABLE-US-00002 TABLE 2 Component, parts by weight EMC-1 EMC-2 EMC-3
EMC-4 EMC-5 EMC-6 (a) Epoxy resin a1 55.44 71.40 71.40 71.40 71.40
Epoxy resin a2 69.16 (b) Phenolic resin b1 28.60 30.84 28.60 28.60
28.60 Phenolic resin b2 44.56 (c) Inorganic filler 800.0 800.0
800.0 900.0 700.0 500.0 Others Curing promoter 1.0 1.0 1.0 1.0 1.0
1.0 Releasing agent 1.5 1.5 1.5 1.5 1.5 1.5 Carbon black 1.0 1.0
1.0 1.0 1.0 1.0 Silane coupling agent 2.0 2.0 2.0 2.0 2.0 2.0
Results Spiral flow inch 58 50 45 35 58 70 Viscosity Pa s 6 8 9 13
5 2 Gel time sec 25 24 20 21 23 23 Specific gravity g/cm.sup.3 1.99
1.99 1.99 2.02 1.92 1.88 Bending strength Kgf/mm.sup.2 155 145 139
140 142 141 Modulus of Kgf/mm.sup.2 22200 21500 22500 28900 17580
15300 elasticity Fracture MPam.sup.1/2 2.4 2.4 2.2 2.4 2.4 2.4
toughness, K.sub.1c Tg .degree. C. 125 155 182 155 155 155 CTE1
ppm/.degree. C. 10 10 10 8 12 15 CTE2 ppm/.degree. C. 38 38 37 32
43 50
Examples 1 to 22, Referential Examples 1 to 19
[0150] Using the underfill compositions and encapsulation resin
compositions as indicated in Table 3, SIP type semiconductor
devices were prepared according to the method described below. The
devices obtained were subjected to a pressure cooker test and a
thermal shock test as described below.
[0151] Preparation of a Semiconductor Device
[0152] A semiconductor device of which cross-sectional view is
shown in FIG. 1 was prepared. On a 0.4 mm-thick
bismaleimide-triazine(BT) resin substrate for preparing a
32.times.32.times.1.2 mm package, nine pieces of
10.times.10.times.0.3 mm silicon chip were mounted by using a
spacer having a thickness of about 100 .mu.m. An underfill
composition was penetrated in a gap between each chip and the
substrate and cured by heating at 120.degree. C. for 0.5 hour and
then at 165.degree. C. for 3 hours.
[0153] The device thus obtained was encapsulated with an
encapsulation resin composition by transfer-molding at 175.degree.
C. and at 6.9 N/mm.sup.2. The encapsulated device was heated for 2
minutes and then at 175.degree. C. for 5 hours to cure the
encapsulation resin composition. Subsequently, the package was
diced with a dicer in nine semiconductor device chips each having a
size of 12 mm.times.12 mm with a thickness of about 3 mm.
[0154] (1) Pressure Cooker Test
[0155] Eighteen semiconductor device chips prepared as described
above were kept in an environment of the level 3 of the Joint
Electron Device Engineering Council (JEDEC) classification, i.e., a
temperature of 30.degree. C. and a relative humidity of 65%, for
192 hours, and then passed in an IR reflow furnace with a maximum
temperature of 265.degree. C. five times. The semiconductor device
chips were inspected for peeling or cracks with a scanning acoustic
microscope, C-SAM, ex SONIX K. K.
[0156] The semiconductor device chips were then kept in a pressure
cooker at 121.degree. C. and at 2.1 atm for 336 hours followed by
inspection with the scanning acoustic microscope. Results are as
shown in Tables 3 to 6 in which "G" indicates that no peeling or
crack was detected and "NG" indicates a peeling and/or crack was
detected.
[0157] (2) Thermal Shock Test
[0158] Eighteen semiconductor device chips prepared as described
above were kept in an environment of a temperature of 30.degree. C.
and a relative humidity of 65% for 192 hours, and passed in an IR
reflow furnace with a maximum temperature of 265.degree. C. five
times. Then, the semiconductor device chips were subjected to a
thermal shock test in which one cycle consisting of cooling at
-65.degree. C. for 30 minutes and heating at 150.degree. C. for 30
minutes. After 250, 500, 750 and 1,000 cycles, the semiconductor
device chips were inspected with the scanning acoustic microscope.
In Tables 3 to 6, percentages of devices in which peeling and/or
crack was detected are shown. In Tables 3 to 6, "Ex." stands for
Example and "R.Ex." stands for Referential Example.
TABLE-US-00003 TABLE 3 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7
Ex. 8 Ex. 9 Ex. 10 Ex. 11 Underfill composition (UF) UF-5 UF-10
UF-11 UF-12 UF-11 UF-12 UF-10 UF-11 UF-12 UF-11 UF-12 Encapsulation
resin EMC-2 EMC-2 EMC-2 EMC-2 EMC-4 EMC-4 EMC-5 EMC-5 EMC-5 EMC-6
EMC-6 composition (EMC) CTE1 of UF, ppm/.degree. C. 28 28 24 17 24
17 28 24 17 24 17 CTE1 of EMC, ppm/.degree. C. 10 10 10 10 8 8 12
12 12 15 15 Total of CTE1, ppm/.degree. C. 38 38 34 27 32 25 40 36
29 39 32 (CTE1 of EMC)/(CTE1 of UF) 0.36 0.36 0.42 0.59 0.33 0.47
0.43 0.50 0.71 0.63 0.88 Tg of UF, .degree. C. 137 137 137 137 137
137 137 137 137 137 137 Tg of EMC, .degree. C. 155 155 155 155 155
155 155 155 155 155 155 (Tg of EMC) - (Tg of UF), .degree. C. -18
-18 -18 -18 -18 -18 -18 -18 -18 -18 -18 JEDEC Level 3 and G G G G G
G G G G G G IR265.degree. C. 5 passes After PCT336hr G G G G G G G
G G G G Thermal shock 250 cycles, % 0 0 0 0 0 0 0 0 0 0 0 500
cycles, % 0 0 0 0 0 0 0 0 0 0 0 750 cycles, % 0 0 0 0 0 0 0 0 0 0
0
TABLE-US-00004 TABLE 4 Ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16 Ex. 17
Ex. 18 Ex. 19 Ex. 20 Ex. 21 Ex. 22 Underfill composition (UF) UF-2
UF-3 UF-5 UF-6 UF-7 UF-8 UF-4 UF-6 UF-7 UF-8 UF-5 Encapsulation
resin EMC-1 EMC-1 EMC-1 EMC-1 EMC-1 EMC-1 EMC-2 EMC-2 EMC-2 EMC-2
EMC-2 composition (EMC) CTE1 of UF, ppm/.degree. C. 29 29 29 29 29
29 29 29 29 29 29 CTE1 of EMC, ppm/.degree. C. 10 10 10 10 10 10 10
10 10 10 10 Total of CTE1, ppm/.degree. C. 39 39 39 39 39 39 39 39
39 39 39 (CTE1 of EMC)/(CTE1 of UF) 0.34 0.34 0.34 0.34 0.34 0.34
0.34 0.34 0.34 0.34 0.34 Tg of UF, .degree. C. 110 125 137 136 140
137 160 136 140 137 137 Tg of EMC, .degree. C. 125 125 125 125 125
125 155 155 155 155 155 (Tg of EMC) - (Tg of UF), .degree. C. -15 0
12 11 15 12 5 -19 -15 -18 -18 JEDEC Level 3 and G G G G G G G G G G
G IR265.degree. C. 5 passes After PCT336hr G G G G G G G G G G G
Thermal shock 250 cycles, % 0 0 0 0 0 0 0 0 0 0 0 500 cycles, % 0 0
0 0 0 0 0 0 0 0 0 750 cycles, % 0 0 0 0 0 0 0 0 0 0 0
TABLE-US-00005 TABLE 5 R. Ex. 1 R. Ex. 2 R. Ex. 3 R. Ex. 4 R. Ex. 5
R. Ex. 6 R. Ex. 7 R. Ex. 8 R. Ex. 9 Underfill composition (UF) UF-9
UF-9 UF-10 UF-9 UF-9 UF-10 UF-1 UF-4 UF-1 Encapsulation resin EMC-2
EMC-4 EMC-4 EMC-5 EMC-6 EMC-6 EMC-1 EMC-1 EMC-2 composition (EMC)
CTE1 of UF, ppm/.degree. C. 42 42 28 42 42 28 29 29 29 CTE1 of EMC,
ppm/.degree. C. 10 8 8 12 15 15 10 10 10 Total of CTE1,
ppm/.degree. C. 52 50 36 54 57 43 39 39 39 (CTE1 of EMC)/(CTE1 of
UF) 0.24 0.19 0.29 0.29 0.36 0.54 0.34 0.34 0.34 Tg of UF, .degree.
C. 137 137 137 137 137 137 95 160 95 Tg of EMC, .degree. C. 155 155
155 155 155 155 125 125 155 (Tg of EMC) - (Tg of UF), .degree. C.
-18 -18 -18 -18 -18 -18 -30 35 -60 JEDEC Level 3 and NG NG NG NG NG
NG NG NG NG IR265.degree. C. 5 passes After PCT336hr NG NG G NG NG
G NG NG NG Thermal shock 250 cycles, % 50 0 0 50 0 0 10 0 10 500
cycles, % 100 0 0 100 0 0 50 0 50 750 cycles, % -- 0 0 -- 0 0 100 0
100
TABLE-US-00006 TABLE 6 R. Ex. R. Ex. R. Ex. R. Ex. R. Ex. R. Ex. R.
Ex. R. Ex. R. Ex. R. Ex. 10 11 12 13 14 15 16 17 18 19 Underfill
composition (UF) UF-2 UF-3 UF-1 UF-2 UF-3 UF-4 UF-5 UF-6 UF-7 UF-8
Encapsulation resin EMC-2 EMC-2 EMC-3 EMC-3 EMC-3 EMC-3 EMC-3 EMC-3
EMC-3 EMC-3 composition (EMC) CTE1 of UF, ppm/.degree. C. 29 29 29
29 29 29 29 29 29 29 CTE1 of EMC, ppm/.degree. C. 10 10 10 10 10 10
10 10 10 10 Total of CTE1, ppm/.degree. C. 39 39 39 39 39 39 39 39
39 39 (CTE1 of EMC)/(CTE1 of UF) 0.34 0.34 0.34 0.34 0.34 0.34 0.34
0.34 0.34 0.34 Tg of UF, .degree. C. 110 125 95 110 125 160 137 136
140 137 Tg of EMC, .degree. C. 155 155 182 182 182 182 182 182 182
182 (Tg of EMC) - (Tg of UF), .degree. C. -45 -30 -87 -72 -57 -22
-45 -46 -42 -45 JEDEC Level 3 and NG NG NG NG NG NG NG NG NG NG
IR265.degree. C. 5 passes After PCT336hr NG NG NG NG NG NG NG NG NG
NG Thermal shock 250 cycles, % 25 0 60 60 0 0 0 0 0 0 500 cycles, %
64 0 100 100 0 0 0 0 0 0 750 cycles, % 100 0 -- -- 0 0 0 0 0 0
[0159] Referential Examples 10 to 22 in which differences in Tg
between the cured products of the underfill and the encapsulation
resin compositions were larger than 20.degree. C. showed peeling
after the pressure cooker test as shown in Tables 5 and 6.
Referential Examples 1, 2, 4 and 5 in which a total of linear
expansion coefficients at (Tg-30).degree. C. exceeded 45
ppm/.degree. C. showed peeling after the reflow process.
Referential Example 3 in which a ratio of the linear expansion
coefficient of the cured encapsulation resin composition to that of
the cured underfill composition was smaller than 0.3 showed peeling
after the reflow process. In contrast to these, the devices in
Examples 1 to 22 did not show any peeling or cracks, and were
resistant to the thermal shock. The composition set of the present
invention is therefore suitable for preparing a system-in-package
type semiconductor device resistant to heat and thermal shock.
* * * * *