U.S. patent application number 10/381052 was filed with the patent office on 2003-10-30 for epoxy resin molding material for sealing.
Invention is credited to Fujii, Masanobu, Hagiwara, Shinsuke, Ikezawa, Ryoichi.
Application Number | 20030201548 10/381052 |
Document ID | / |
Family ID | 27573722 |
Filed Date | 2003-10-30 |
United States Patent
Application |
20030201548 |
Kind Code |
A1 |
Ikezawa, Ryoichi ; et
al. |
October 30, 2003 |
Epoxy resin molding material for sealing
Abstract
An encapsulating epoxy resin molding material comprising (A) an
epoxy resin, (B) a curing agent, and (C) a silane coupling agent
having a secondary amino group or (D) a phosphate, and
semiconductor devices encapsulated therein. The encapsulating epoxy
resin molding material for thin semiconductor devices according to
this invention is excellent in fluidity, and the semiconductor
device encapsulated therein, which is a semiconductor device having
a semiconductor chip arranged on a thin, multi-pin, long wire,
narrow-pad-pitch, or on a mounted substrate such as organic
substrate or organic film, is free of molding defects such as wire
sweep, voids etc. as shown in the Examples, and thus its industrial
value is significant.
Inventors: |
Ikezawa, Ryoichi;
(Tsukuba-shi, JP) ; Fujii, Masanobu;
(Shimodate-shi, JP) ; Hagiwara, Shinsuke;
(Shimodate-shi, JP) |
Correspondence
Address: |
ARMSTRONG,WESTERMAN & HATTORI, LLP
1725 K STREET, NW
SUITE 1000
WASHINGTON
DC
20006
US
|
Family ID: |
27573722 |
Appl. No.: |
10/381052 |
Filed: |
March 25, 2003 |
PCT Filed: |
September 25, 2001 |
PCT NO: |
PCT/JP01/08303 |
Current U.S.
Class: |
257/793 ;
257/E23.119 |
Current CPC
Class: |
H01L 2224/73265
20130101; H01L 24/97 20130101; H01L 2924/15311 20130101; H01L
2224/97 20130101; H01L 23/293 20130101; H01L 2924/09701 20130101;
H01L 2924/15787 20130101; Y10T 428/31511 20150401; H01L 2224/48091
20130101; H01L 2224/49175 20130101; H01L 2224/32225 20130101; H01L
2924/12044 20130101; H01L 2224/05554 20130101; H01L 2924/181
20130101; H01L 2224/32245 20130101; H01L 2224/45144 20130101; H01L
2924/1301 20130101; C08K 5/5455 20130101; H01L 2224/48247 20130101;
H01L 2224/48227 20130101; C08K 5/521 20130101; C08K 5/521 20130101;
C08L 63/00 20130101; C08K 5/5455 20130101; C08L 63/00 20130101;
H01L 2224/48091 20130101; H01L 2924/00014 20130101; H01L 2224/73265
20130101; H01L 2224/32245 20130101; H01L 2224/48247 20130101; H01L
2924/00 20130101; H01L 2224/73265 20130101; H01L 2224/32225
20130101; H01L 2224/48227 20130101; H01L 2924/00 20130101; H01L
2224/45144 20130101; H01L 2924/00 20130101; H01L 2924/15311
20130101; H01L 2224/73265 20130101; H01L 2224/32225 20130101; H01L
2224/48227 20130101; H01L 2924/00 20130101; H01L 2224/97 20130101;
H01L 2224/73265 20130101; H01L 2224/32225 20130101; H01L 2224/48227
20130101; H01L 2924/00 20130101; H01L 2224/97 20130101; H01L
2224/73265 20130101; H01L 2224/32245 20130101; H01L 2224/48247
20130101; H01L 2924/00 20130101; H01L 2924/1301 20130101; H01L
2924/00 20130101; H01L 2924/15787 20130101; H01L 2924/00 20130101;
H01L 2224/49175 20130101; H01L 2224/48227 20130101; H01L 2924/00
20130101; H01L 2224/49175 20130101; H01L 2224/48247 20130101; H01L
2924/00 20130101; H01L 2924/181 20130101; H01L 2924/00012 20130101;
H01L 2224/73265 20130101; H01L 2224/32245 20130101; H01L 2224/48247
20130101; H01L 2924/00012 20130101 |
Class at
Publication: |
257/793 |
International
Class: |
H01L 023/29 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 25, 2000 |
JP |
2000-291067 |
Dec 28, 2000 |
JP |
2000-402358 |
Dec 28, 2000 |
JP |
2000-402359 |
Dec 28, 2000 |
JP |
2000-402360 |
Dec 28, 2000 |
JP |
2000-402361 |
Dec 28, 2000 |
JP |
2000-402362 |
Dec 28, 2000 |
JP |
2000-402363 |
Mar 22, 2001 |
JP |
2001-082741 |
Claims
1. An encapsulating epoxy resin molding material comprising (A) an
epoxy resin, (B) a curing agent, and (C) a silane coupling agent
having a secondary amino group or (D) a phosphate, wherein a disk
flow is 80 mm or more.
2. An encapsulating epoxy resin molding material comprising (A) an
epoxy resin, (B) a curing agent, and (C) a silane coupling agent
having a secondary amino group or (D) a phosphate, wherein the
encapsulating epoxy resin molding material is used for the
semiconductor device having at least one of the following
constitutions (a) to (f): (a) at least one of an encapsulating
material of an upper side of a semiconductor chip and an
encapsulating material of a lower side of the semiconductor chip
has a thickness 0.7 mm or less; (b) the pin count is 80 or more;
(c) the length of the wire is 2 mm or more; (d) the pad pitch on
the semiconductor chip is 90 .mu.m or less; (e) the thickness of a
package, in which the semiconductor chip is disposed on a mounting
substrate, is 2 mm or less; (f) the area of the semiconductor chip
is 25 mm.sup.2 or more.
3. The encapsulating epoxy resin molding material described in
claim 2, wherein the disk flow is 80 mm or more.
4. The encapsulating epoxy resin molding material described in any
one of claims 1 to 3, which further comprises (E) an inorganic
filler.
5. The encapsulating epoxy resin molding material described in any
one of claims 1 to 4, which further comprises (F) a curing
accelerator.
6. The encapsulating epoxy resin molding material described in any
one of claims 1 to 5, wherein the semiconductor device is a stacked
type package.
7. The encapsulating epoxy resin molding material described in any
one of claims 1 to 6, wherein the semiconductor device is a mold
array package.
8. The encapsulating epoxy resin molding material described in any
one of claims 1 to 7, wherein the melt viscosity of the epoxy resin
(A) at 150.degree. C. is 2 poises or less.
9. The encapsulating epoxy resin molding material described in any
one of claims 1 to 8, wherein the epoxy resin (A) comprises at
least one member of: a biphenyl type epoxy resin represented by the
general formula (I): 17wherein R.sup.1 to R.sup.4 may be the same
or different and are selected from a hydrogen atom and a C.sub.1-10
substituted or unsubstituted monovalent hydrocarbon group, and n is
an integer of 0 to 3, a bisphenol F type epoxy resin represented by
the general formula (II): 18wherein R.sup.1 to R.sup.8 may be the
same or different and are selected from a hydrogen atom, a
C.sub.1-10 alkyl group, a C.sub.1-10 alkoxy group, a C.sub.6-10
aryl group, and a C.sub.6-10 aralkyl group, and n is an integer of
0 to 3, and a stilbene type epoxy resin represented by the general
formula (III): 19wherein R.sup.1 to R.sup.8 may be the same or
different and are selected from a hydrogen atom, a C.sub.1-10 alkyl
group, a C.sub.1-10 alkoxy group, a C.sub.6-10 aryl group and a
C.sub.6-10 aralkyl group, and n is an integer of 0 to 3.
10. The encapsulating epoxy resin molding material described in any
one of claims 1 to 9, wherein the melt viscosity of the curing
agent (B) at 150.degree. C. is 2 poises or less.
11. The encapsulating epoxy resin molding material described in any
one of claims 1 to 10, wherein the curing resin (B) comprises: a
phenol-aralkyl resin represented by the general formula (IV):
20wherein R is selected from a hydrogen atom and a C.sub.1-10
substituted or unsubstituted monovalent hydrocarbon group, and n is
an integer of 0 to 10, and/or a biphenyl type phenol resin
represented by the general formula (V): 21wherein R.sup.1 to
R.sup.9 may be the same or different and are selected from a
hydrogen atom, a C.sub.1-10 alkyl group, a C.sub.1-10 alkoxy group,
a C.sub.6-10 aryl group and a C.sub.6-10 aralkyl group, and n is an
integer of 0 to 10.
12. The encapsulating epoxy resin molding material described in any
one of claims 1 to 11, wherein the silane coupling agent having a
secondary amino group (C) comprises a compound represented by the
general formula (VI): 22wherein R.sup.1 is selected from a hydrogen
atom, a C.sub.1-6 alkyl group and a C.sub.1-2 alkoxy group, R.sup.2
is selected from a C.sub.1-6 alkyl group and a phenyl group,
R.sup.3 represents methyl or ethyl group, n is an integer of 1 to
6, and m is an integer of 1 to 3.
13. The encapsulating epoxy resin molding material described in any
one of claims 1 to 11, wherein the phosphate (D) comprises a
compound represented by the general formula (X): 23wherein eight R
groups may be the same or different and represent a C.sub.1-4 alkyl
group, and Ar represents an aromatic group.
14. A semiconductor device encapsulated in the encapsulating epoxy
resin molding material described in any one of claims 1 to 13.
15. The semiconductor device described in the claim 14, having at
least one of the following constitutions (a) to (f): (a) at least
one of an encapsulating material of an upper side of a
semiconductor chip and an encapsulating material of a lower side of
the semiconductor chip has a thickness 0.7 mm or less; (b) the pin
count is 80 or more; (c) the length of the wire is 2 mm or more;
(d) the pad pitch on the semiconductor chip is 90 .mu.m or less;
(e) the thickness of a package, in which the semiconductor chip is
disposed on a mounting substrate, is 2 mm or less; (f) the area of
the semiconductor chip is 25 mm.sup.2 or more.
Description
TECHNICAL FIELD
[0001] This invention relates to an epoxy resin molding material
for encapsulation and a semiconductor device encapsulated therein.
More specifically, this invention relates to an epoxy resin molding
material for encapsulation excellent in fluidity and suitable for a
thin semiconductor device having a semiconductor chip arranged on a
thin, multi-pin, long wire, narrow pad pitch or mounted substrate
to a thin semiconductor device encapsulated therein with less
generation of molding defects such as wire sweep and voids and
having a semiconductor chip arranged on a thin, multi-pin, long
wire, narrow pad pitch or mounted substrate.
RELATED ART
[0002] High-density mounting on printed wiring boards for
electronic parts is advancing in recent years. To cope therewith,
packages of surface mounting type have come to be mainly used for
semiconductor devices in place of conventional packages of pin
insertion type. For increasing the density of mounting to decrease
the height of mounting, IC and LSI of surface mounting type are in
the form of a thin and small package where the ratio by volume of
an element to the package is becoming high and the thickness of the
package is becoming very thin. The area of the chip and pin count
are being increased with multifunctionalization and higher capacity
of the element and moreover as, the number of pad (electrode) is
increasing, a reduction in pad pitch and a reduction in pad
dimension, that is, narrowing of pad pitch is also advancing.
[0003] To cope with a further reduction in size and weight, the
form of the package is being switched from QFP (Quad Flat Package)
and SOP (Small Outline Package) and the like to CSP (Chip Size
Package) and BGA (Ball Grid Array) coping more easily with a large
pin count and capable of high-density mounting. New structures such
as those of phase down type, stacked type, flip chip type, wafer
level type etc. have been developed in recent years for these
packages to effect higher speed and multifunctionalization. Among
these, the stacked type structure is a structure wherein a
plurality of chips are piled up in a package and connected by wire
bonding so that a plurality of chips having different functions can
be mounted in one package, thus achieving
multifunctionalization.
[0004] In place of a conventional one-chip-one-cavity encapsulating
method used in the step of encapsulation with resin in producing
CSP and BGA, a mold array package type encapsulating method of
encapsulating a plurality of chips with one cavity has been
developed to effect an improvement in production efficiency and a
reduction in costs.
[0005] On one hand, the encapsulating material is required to solve
re-flow resistance as a problem upon mounting a semiconductor
device on the surface of a printed circuit board and to
sufficiently satisfy temperature cycling etc. required for
reliability after mounting, and the encapsulating material is
endowed with low moisture absorptivity and low expansibility by
reduction in the resin viscosity and higher charging of fillers, in
order to cope therewith.
DISCLOSURE OF INVENTION
[0006] However, the conventional encapsulating material often
generates molding defects such as wire sweep and voids, thus making
it difficult to produce thinner semiconductor devices, a larger
area of chip, an increased pin count, narrower pad pitch, etc. To
cope therewith, improvements in the encapsulating material have
been attempted by further reduction in the resin viscosity and a
change in the composition of fillers, but satisfactory results are
still not obtained. A stricter fluidity characteristic is required
for the encapsulating material for use in stacked type CSP for long
wire or in semiconductor devices moldable by mold array package
type molding with a high cavity volume.
[0007] Accordingly, an encapsulating epoxy resin molding material
for semiconductor devices which is excellent in fluidity, as well
as a semiconductor device encapsulated therein with less generation
of molding defects such as wire sweep, voids etc. are required.
[0008] In one preferable embodiment, there is provided an epoxy
resin molding material for encapsulation suitable for encapsulating
a semiconductor device having a semiconductor chip arranged on a
thin, multi-pin, long wire, narrow pad pitch or on a mounted
substrate such as organic substrate or organic film.
[0009] In another preferable embodiment, there is provided a
semiconductor device having a semiconductor chip arranged on a
thin, multi-pin, long wire, narrow pad pitch or on a mounted
substrate such as organic substrate or organic film, which has been
encapsulated in the encapsulating epoxy resin molding material of
the invention.
[0010] To solve the problem described above, an extensive study was
made by the inventers, and as a result, it was found that the
problem described above can be solved by a particular encapsulating
epoxy resin molding material comprising a silane coupling agent
having a secondary amino group, or a phosphate, as an essential
component and by a semiconductor device encapsulated therein.
[0011] That is, this invention relates to:
[0012] (1) An encapsulating epoxy resin molding material comprising
(A) an epoxy resin, (B) a curing agent, and (C) a silane coupling
agent having a secondary amino group or (D) a phosphate, wherein a
disk flow is 80 mm or more.
[0013] (2) An encapsulating epoxy resin molding material comprising
(A) an epoxy resin, (B) a curing agent, and (C) a silane coupling
agent having a secondary amino group or (D) a phosphate, wherein
the encapsulating epoxy resin molding material is used for the
semiconductor device having at least one of the following
constitutions (a) to (f):
[0014] (a) at least one of an encapsulating material of an upper
side of a semiconductor chip and an encapsulating material of a
lower side of the semiconductor chip has a thickness 0.7 mm or
less;
[0015] (b) the pin count is 80 or more;
[0016] (c) the length of the wire is 2 mm or more;
[0017] (d) the pad pitch on the semiconductor chip is 90 .mu.m or
less;
[0018] (e) the thickness of a package, in which the semiconductor
chip is disposed on a mounting substrate, is 2 mm or less.
[0019] (f) the area of the semiconductor chip is 25 mm.sup.2 or
more.
[0020] (3) The encapsulating epoxy resin molding material described
in the above-mentioned (2), wherein the disk flow is 80 mm or
more.
[0021] (4) The encapsulating epoxy resin molding material described
in any one of the above-mentioned (1) to (3), which further
comprises (E) an inorganic filler.
[0022] (5) The encapsulating epoxy resin molding material described
in any one of the above-mentioned (1) to (4), which further
comprises (F) a curing accelerator.
[0023] (6) The encapsulating epoxy resin molding material described
in any one of the above-mentioned (1) to (5), wherein the
semiconductor device is a stacked type package.
[0024] (7) The encapsulating epoxy resin molding material described
in anyone of the above-mentioned (1) to (6), wherein the
semiconductor device is a mold array package.
[0025] (8) The encapsulating epoxy resin molding material described
in anyone of the above-mentioned (1) to (7), wherein the melt
viscosity of the epoxy resin (A) at 150.degree. C. is 2 poises or
less.
[0026] (9) The encapsulating epoxy resin molding material described
in anyone of the above-mentioned (1) to (8), wherein the epoxy
resin (A) comprises at least one member of:
[0027] a biphenyl type epoxy resin represented by the general
formula (I): 1
[0028] wherein R.sup.1 to R.sup.4may be the same or different and
are selected from a hydrogen atom and a C.sub.1-10 substituted or
unsubstituted monovalent hydrocarbon group, and n is an integer of
0 to 3,
[0029] a bisphenol F type epoxy resin represented by the general
formula (II): 2
[0030] wherein R.sup.1 to R.sup.8 may be the same or different and
are selected from a hydrogen atom, a C.sub.1-10 alkyl group, a
C.sub.1-10 alkoxy group, a C.sub.6-10 aryl group, and a C.sub.6-10
aralkyl group, and n is an integer of 0 to 3, and
[0031] a stilbene type epoxy resin represented by the general
formula (III): 3
[0032] wherein R.sup.1 to R.sup.8 may be the same or different and
are selected from a hydrogen atom, a C.sub.1-10 alkyl group, a
C.sub.1-10 alkoxy group, a C.sub.6-10 aryl group and a C.sub.6-10
aralkyl group, and n is an integer of 0 to 3.
[0033] (10) The encapsulating epoxy resin molding material
described in any one of the above-mentioned (1) to (9), wherein the
melt viscosity of the curing agent (B) at 150.degree. C. is 2
poises or less.
[0034] (11) The encapsulating epoxy resin molding material
described in any one of the above-mentioned (1) to (10), wherein
the curing resin (B) comprises:
[0035] a phenol-aralkyl resin represented by the general formula
(IV): 4
[0036] wherein R is selected from a hydrogen atom and a C.sub.1-10
substituted or unsubstituted monovalent hydrocarbon group, and n is
an integer of 0 to 10, and/or
[0037] a biphenyl type phenol resin represented by the general
formula (V): 5
[0038] wherein R.sup.1 to R.sup.9 may be the same or different and
are selected from a hydrogen atom, a C.sub.1-10 alkyl group, a
C.sub.1-10 alkoxy group, a C.sub.6-10 aryl group and a C.sub.6-10
aralkyl group, and n is an integer of 0 to 10.
[0039] (12) The encapsulating epoxy resin molding material
described in any one of the above-mentioned (1) to (11), wherein
the silane coupling agent having a secondary amino group (C)
comprises a compound represented by the general formula (VI): 6
[0040] wherein R.sup.1 is selected from a hydrogen atom, a
C.sub.1-6 alkyl group and a C.sub.1-2 alkoxy group, R.sup.2 is
selected from a C.sub.1-6 alkyl group and a phenyl group, R.sup.3
represents methyl or ethyl group, n is an integer of 1 to 6, and m
is an integer of 1 to 3.
[0041] (13) The encapsulating epoxy resin molding material
described in any one of the above-mentioned (1) to (11), wherein
the phosphate (D) comprises a compound represented by the general
formula (X): 7
[0042] wherein eight R groups may be the same or different and
represent a C.sub.1-4 alkyl group, and Ar represents an aromatic
group.
[0043] (14) A semiconductor device encapsulated in the
encapsulating epoxy resin molding material described in any one of
the above-mentioned (1) to (13).
[0044] (15) The semiconductor device described in the
above-mentioned (14), having at least one of the following
constitutions (a) to (f):
[0045] (a) at least one of an encapsulating material of an upper
side of a semiconductor chip and an encapsulating material of a
lower side of the semiconductor chip has a thickness 0.7 mm or
less;
[0046] (b) the pin count is 80 or more,
[0047] (c) the length of the wire is 2 mm or more,
[0048] (d) the pad pitch on the semiconductor chip is 90 .mu.m or
less,
[0049] (e) the thickness of a package, in which the semiconductor
chip is disposed on a mounting substrate, is 2 mm or less;
[0050] (f) the area of the semiconductor chip is 25 mm.sup.2 or
more.
[0051] This application claims priority rights of Japanese Patent
Applications previously filed by the same applicant, that is,
Japanese Patent Application No. 2000-291067 (filing date: Sep. 25,
2000), Japanese Patent Application No. 2000-402358 (filing date:
Dec. 28, 2000), Japanese Patent Application No. 2000-402359 (filing
date: Dec. 28, 2000), Japanese Patent Application No. 2000-402360
(filing date: Dec. 28, 2000), Japanese Patent Application No.
2000-402361 (filing date: Dec. 28, 2000), Japanese Patent
Application No. 2000-402362 (filing date: Dec. 28, 2000), Japanese
Patent Application No. 2000-402363 (filing date: Dec. 28, 2000) and
Japanese Patent Application No. 2001-82741 (filing date: Mar. 22,
2001), and these specifications are incorporated herein by
reference.
BRIEF DESCRIPTION OF DRAWINGS
[0052] FIG. 1 shows (a) a sectional view, (b) an upper-surface
(partially see-through) view and (c) an enlarged view of a region
of bonding pads in a semiconductor device (QFP).
[0053] FIG. 2 is a drawing showing a method of measuring the wire
sweep.
[0054] FIG. 3 shows (a) a sectional view, (b) an upper-surface
(partially see-through) view and (c) an enlarged view of a region
of bonding pads in a semiconductor device (BGA).
[0055] FIG. 4 is a drawing showing a method of measuring the
deformation of a wire.
[0056] FIG. 5 is a drawing of a mold array package type BGA
device.
DESCRIPTION OF SYMBOLS
[0057] 1: Island (tab).
[0058] 2: Die attach
[0059] 3: Semiconductor chip.
[0060] 4: Lead pin.
[0061] 5: Wire.
[0062] 6: Epoxy resin molding material for encapsulation
(encapsulating material).
[0063] 7: Terminal (bonding pad).
[0064] 8: Insulating base substrate.
[0065] 9: Solder ball.
[0066] 10: Terminal on the wiring board.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0067] According to this invention, there is provided an
encapsulating epoxy resin molding material suitable for
encapsulating a semiconductor device having a semiconductor chip
arranged on a thin, multi-pin, long wire, narrow pad pitch, or on a
mounted substrate such as organic substrate or organic film
[0068] According to this invention, there is also provided a
semiconductor device having a semiconductor chip arranged on a
thin, multi-pin, long wire, narrow pad pitch, or on a mounted
substrate such as organic substrate or organic film, which is
encapsulated by the encapsulating epoxy resin molding material of
the invention.
[0069] Hereinafter, the respective components used in the
encapsulating epoxy resin molding material of the invention are
described.
[0070] The epoxy resin (A) used in this invention is not
particularly limited insofar as it is generally used in
encapsulating epoxy resin molding materials, and examples thereof
include phenol novolak type epoxy resin and o-cresol novolak type
epoxy resin, for example a resin obtained by epoxidation of a
novolak resin obtained in the presence of an acid catalyst by
condensation of phenols such as phenol, cresol, xylenol, resorcin,
catechol, bisphenol A, bisphenol F etc. and/or naphthols such as
.alpha.-naphthol, .beta.-naphthol, dihydroxynaphthalene etc., or by
co-condensation thereof with compounds containing an aldehyde
group, such as formaldehyde, acetaldehyde, propionaldehyde,
benzaldehyde, salicylaldehyde etc.; glycidyl ether (e.g. diglycidyl
ether) type epoxy resin made from bisphenol A, bisphenol F,
bisphenol S, or alkyl substituted or unsubstituted biphenol;
stilbene type epoxy resin; a sulfur atom-containing epoxy resin; a
hydroquinone type epoxy resin; a glycidyl ester type epoxy resin
obtained by reacting a polybasic acid such as phthalic acid,
dimeric acid etc. with epichlorohydrin; a glycidyl amine type epoxy
resin obtained by reacting a polyamine such as diaminodiphenyl
methane, isocyanuric acid etc. with epichlorohydrin, an epoxidated
product of a resin obtained by co-condensation of dicyclopentadiene
with phenols and/or naphthols; an epoxy resin having a naphthalene
ring; an epoxidated product of an aralkyl type phenol resin such as
phenol-aralkyl resin, naphthol-aralkyl resin etc.; a trimethylol
propane type epoxy resin; a terpene-modified epoxy resin; a linear
aliphatic epoxy resin obtained by oxidizing olefin bonds with a
peracid such as peracetic acid, and an aliphatic epoxy resin, and
these may be used singly or in combination thereof.
[0071] Particularly from the viewpoint of flowability and
re-flowing resistance, a biphenyl type epoxy resin represented by
the following general formula (I) is preferable. 8
[0072] wherein R.sup.1 to R.sup.4 are selected from a hydrogen atom
and C-.sub.1-10 substituted or unsubstituted monovalent hydrocarbon
groups, and all the groups may be the same or different, and n is
an integer of 0 to 3.
[0073] The biphenyl type epoxy resin represented by the general
formula (I) includes, for example, an epoxy resin based on
4,4'-bis(2,3-epoxypropoxy) biphenyl or
4,4'-bis(2,3-epoxypropoxy)-3,3',5,- 5'-tetramethyl biphenyl and an
epoxy resin obtained by reacting epichlorohydrin with 4,4'-biphenol
or 4,4'-(3,3',5,5'-tetramethyl) biphenol. In particular, the epoxy
resin based on 4,4'-bis(2,3-epoxypropo- xy)-3,3',5,5'-tetramethyl
biphenyl is preferable. When this biphenyl type epoxy resin is
used, its compounding amount is preferably 30% by weight or more,
more preferably 50% by weight or more, still more preferably 60% by
weight or more, relative to the total amount of the epoxy resin, in
order to exhibit its performance.
[0074] From the viewpoint of flowability and flame retardancy,
bisphenol F type epoxy resin represented by the following general
formula (II) is preferable. 9
[0075] wherein R.sup.1 to R.sup.8 may be the same or different and
are selected from a hydrogen atom, C.sub.1-10 alkyl groups such as
methyl group, ethyl group, propyl group, butyl group, isopropyl
group, isobutyl group etc. C.sub.1-10 alkoxy groups such as methoxy
group, ethoxy group, propoxy group, butoxy group etc., C.sub.6-10
aryl groups such as phenyl group, tolyl group, xylyl group etc.,
and C.sub.6-10 aralkyl groups such as benzyl group, phenethyl group
etc., among which a hydrogen atom and a methyl group are
preferable, and n is an integer of 0 to 3.
[0076] A commercial product based on the bisphenol F type epoxy
resin represented by the general formula (II) wherein each of
R.sup.1, R.sup.3, R.sup.6 and R.sup.8 is a methyl group, each of
R.sup.2, R.sup.4, R.sup.5 and R.sup.7 is a hydrogen atom and n is
0, is available under the trade name YSLV-80XY (a product of Nippon
Steel Chemical Co., Ltd.). When this bisphenol F type epoxy resin
is used, its compounding amount is preferably 30% by weight or
more, more preferably 50% by weight or more, relative to the total
amount of the epoxy resin, in order to exhibit its performance.
[0077] From the viewpoint of flowability and curing properties,
stilbene type epoxy resin represented by the following general
formula (III) is preferable. 10
[0078] wherein R.sup.1 to R.sup.8 are selected from a hydrogen
atom, a C.sub.1-10 alkyl group, C.sub.1-10 alkoxy group, C.sub.6-10
aryl group and C.sub.6-10 aralkyl group, and all of the groups may
be the same or different, and n is an integer of 0 to 3.
[0079] A commercial product based on the stilbene type epoxy resin
represented by the general formula (III) wherein each of R.sup.1,
R.sup.3, R.sup.6 and R.sup.8 is a methyl group, each of R.sup.2,
R.sup.4, R.sup.5 and R.sup.7 is a hydrogen atom and n is 0, is
available under the trade name ESLV-210 (a product of Sumitomo
Chemical Co., Ltd.). When this stilbene type epoxy resin is used,
its compounding amount is preferably 30% by weight or more, more
preferably 50% by weight or more, relative to the total amount of
the epoxy resin, in order to exhibit its performance.
[0080] From the viewpoint of re-flow resistance, a sulfur
atom-containing epoxy resin represented by the following general
formula (VII) is preferable. 11
[0081] wherein R.sup.1 to R.sup.8 may be the same or different, and
are selected from a hydrogen atom, a C.sub.1-10 alkyl group such as
methyl group, ethyl group, propyl group, butyl group, isopropyl
group, isobutyl group etc., a C.sub.1-10 alkoxy group such as
methoxy group, ethoxy group, propoxy group, butoxy group etc., a
C.sub.6-10 aryl group such as phenyl group, tolyl group, xylyl
group etc., and a C.sub.6-10 aralkyl group such as benzyl group,
phenethyl group etc., among which a hydrogen atom, a methyl group
and an isobutyl group are preferable, and n is an integer of 0 to
3.
[0082] A commercial product based on the sulfur atom-containing
epoxy resin represented by the general formula (VII) wherein each
of R.sup.1 and R.sup.8 is a methyl group, each of R.sup.3 and
R.sup.6 is an isobutyl group, each of R.sup.2, R.sup.4, R.sup.5 and
R.sup.7 is a hydrogen atom and n is 0, is available under the trade
name YSLV-120TE (a product of Nippon Steel Chemical Co., Ltd.).
When this sulfur atom-containing epoxy resin is used, its
compounding amount is preferably 30% by weight or more, more
preferably 50% by weight or more, relative to the total amount of
the epoxy resin, in order to exhibit its performance.
[0083] To achieve the effect of the invention, it is more
preferable to employ at least one member selected from the biphenyl
type epoxy resin represented by the general formula (I) above, the
bisphenol F type epoxy resin represented by the general formula
(II) above and the stilbene type epoxy resin represented by the
general formula (III) above, and two or all of these resins may be
used in combination. When two or more resins are used in
combination, their total compounding amount is preferably 60% by
weight or more, more preferably 80% by weight or more, relative to
the total amount of the epoxy resin.
[0084] From the viewpoint of flowability, the melt viscosity at
150.degree. C. of the epoxy resin (A) used in this invention is
preferably 2 P or less, more preferably 1 P or less, still more
preferably 0.5 P or less. The melt viscosity refers to viscosity
determined by an ICI cone plate viscometer.
[0085] The curing agent (B) used in this invention is not
particularly limited insofar as it is generally used in
encapsulating epoxy resin molding materials, and examples thereof
include resins obtained in the presence of an acid catalyst by
condensation of phenols such as phenol, cresol, resorcin, catechol,
bisphenol A, bisphenol F, phenylphenol, aminophenol etc. and/or
naphthols such as .alpha.-naphthol, .beta.-naphthol, dihydroxy
naphthalene etc., or by co-condensation thereof with a compound
having an aldehyde group, such as formaldehyde, and aralkyl type
phenol resins such as phenol-aralkyl resin, naphthol-aralkyl resin
etc. synthesized from phenols and/or naphthols and
dimethoxyparaxylene or bis(methoxymethyl)biphenyl, and these may be
used singly or in combination thereof.
[0086] From the viewpoint of re-flow resistance, a phenol-aralkyl
resin represented by the following general formula (IV) is
preferable, and a phenol-aralkyl resin wherein R is a hydrogen atom
and n is 0 to 8 on average is more preferable, and examples of such
resin include p-xylylene type xyloc[phonetic transcription],
m-xylylene type xyloc etc. When this phenol-aralkyl resin is used,
its compounding amount is preferably 30% by weight or more, more
preferably 50% by weight or more, still more preferably 60% by
weight or more, relative to the total amount of the curing agent,
in order to exhibit its performance. 12
[0087] wherein R is selected from a hydrogen atom and a C.sub.1-10
substituted or unsubstituted monovalent hydrocarbon group, and n is
an integer of 0 to 10.
[0088] From the viewpoint of flame retardancy, a biphenyl type
phenol resin represented by the general formula (V) is preferable.
13
[0089] wherein R.sup.1 to R.sup.9 may be the same or different, and
are selected from a hydrogen atom, a C.sub.1-10 alkyl group such as
methyl group, ethyl group, propyl group, butyl group, isopropyl
group, isobutyl group etc., a C.sub.1-10 alkoxy group such as
methoxy group, ethoxy group, propoxy group, butoxy group etc., a
C.sub.6-10 aryl group such as phenyl group, tolyl group, xylyl
group etc., and a C.sub.6-10 aralkyl group such as benzyl group,
phenethyl group etc., among which a hydrogen atom and a methyl
group are preferable, and n is an integer of 0 to 10.
[0090] The biphenyl type phenol resin represented by the general
formula (V) includes, for example, a compound wherein each of
R.sup.1 to R.sup.9 is a hydrogen atom, and particularly a
condensate mixture containing at least 50% by weight of condensates
wherein n is 1 or more is preferable from the viewpoint of melt
viscosity. Such compound is commercially available under the trade
name MEH-7851 (a product of Meiwa Plastic Industries Ltd.). When
this biphenyl type phenol resin is used, its compounding amount is
preferably 30% by weight or more, more preferably 50% by weight or
more, relative to the total amount of the curing agent, in order to
exhibit its performance.
[0091] The phenol-aralkyl resin represented by the general formula
(IV) may be used in combination with the biphenyl type phenol resin
represented by the general formula (V). When the two are used in
combination, their total compounding amount is preferably 60% by
weight or more, more preferably 80% by weight or more, relative to
the total amount of the curing agent.
[0092] From the viewpoint of flowability, the melt viscosity at
150.degree. C. of the curing agent (B) used in this invention is
preferably 2 P or less, more preferably 1 P or less. The melt
viscosity refers to ICI viscosity.
[0093] The equivalent ratio of the epoxy resin (A) to the curing
agent (B), that is, the ratio of the number of epoxy groups in the
epoxy resin to the number of hydroxyl groups in the curing agent is
not particularly limited, but the ratio is set preferably in the
range of 0.5 to 2, more preferably in the range of 0.6 to 1.3, in
order to reduce the amount of unreacted materials. For obtaining
the encapsulating epoxy resin molding material excellent in
moldability and re-flow resistance, the ratio is set more
preferably in the range of 0.8 to 1.2.
[0094] The silane coupling agent having a secondary amino group (C)
used in this invention is not particularly limited insofar as it is
a silane compound having a secondary amino group in the molecule,
and examples thereof include .gamma.-anilinopropyltrimethoxy
silane, .gamma.-anilinopropyltriethoxy silane,
.gamma.-anilinopropylmethyldimetho- xy silane,
.gamma.-anilinopropylmethyldiethoxy silane,
.gamma.-anilinopropylethyldiethoxy silane,
.gamma.-anilinopropylethyldime- thoxy silane,
.gamma.-anilinomethyltrimethoxy silane,
.gamma.-anilinomethyltriethoxy silane,
.gamma.-anilinomethylmethyldimetho- xy silane,
.gamma.-anilinomethylmethyldiethoxy silane,
.gamma.-anilinomethylethyldiethoxy silane,
.gamma.-anilinomethylethyldime- thoxy silane,
N-(p-methoxyphenyl)-.gamma.-aminopropyltrimethoxy silane,
N-(p-methoxyphenyl)-.gamma.-aminopropyltriethoxy silane,
N-(p-methoxyphenyl)-.gamma.-aminopropylmethyldimethoxy silane,
N-(p-methoxyphenyl)-.gamma.-aminopropylmethyldiethoxy silane,
N-(p-methoxyphenyl)-.gamma.-aminopropylethyldiethoxy silane,
N-(p-methoxyphenyl)-.gamma.-aminopropylethyldimethoxy silane,
.gamma.-(N-methyl)aminopropyltrimethoxy silane,
.gamma.-(N-ethyl)aminopro- pyltrimethoxy silane,
.gamma.-(N-butyl)aminopropyltrimethoxy silane,
.gamma.-(N-benzyl)aminopropyltrimethoxy silane,
.gamma.-(N-methyl)aminopr- opyltriethoxy silane,
.gamma.-(N-ethyl)aminopropyltriethoxy silane,
.gamma.-(N-butyl)aminopropyltriethoxy silane,
.gamma.-(N-benzyl)aminoprop- yltriethoxy silane,
.gamma.-(N-methyl)aminopropylmethyldimethoxy silane,
.gamma.-(N-ethyl)aminopropylmethyldimethoxy silane,
.gamma.-(N-butyl)aminopropylmethyldimethoxy silane,
.gamma.-(N-benzyl)aminopropylmethyldimethoxy silane,
N-.beta.-(aminoethyl)-.gamma.-aminopropyltrimethoxy silane,
.gamma.-(.beta.-aminoethyl)aminopropyltrimethoxy silane,
N-.beta.-(N-vinylbenzylaminoethyl)-.gamma.-aminopropyl trimethoxy
silane, etc. Particularly from the viewpoint of achieving
flowability and particularly excellent disk flow, an amino silane
coupling agent represented by the general formula (VI) is
preferable. 14
[0095] wherein R.sup.1 is selected from a hydrogen atom, a
C.sub.1-6 alkyl group and a C.sub.1-2 alkoxy group, R.sup.2 is
selected from a C.sub.1-6 alkyl group and a phenyl group, R.sup.3
represents a methyl or ethyl group, n is an integer of 1 to 6, and
m is an integer of 1 to 3.
[0096] The aminosilane coupling agent represented by the general
formula (VI) includes, for example, .gamma.-anilinopropyltrimethoxy
silane, .gamma.-anilinopropyltriethoxy silane,
.gamma.-anilinopropylmethyldimetho- xy silane,
.gamma.-anilinopropylmethyldiethoxy silane,
.gamma.-anilinopropylethyldiethoxy silane,
.gamma.-anilinopropylethyldime- thoxy silane,
.gamma.-anilinomethyltrimethoxy silane,
.gamma.-anilinomethyltriethoxy silane,
.gamma.-anilinomethylmethyldimetho- xy silane,
.gamma.-anilinomethylmethyldiethoxy silane,
.gamma.-anilinomethylethyldiethoxy silane,
.gamma.-anilinomethylethyldime- thoxy silane,
N-(p-methoxyphenyl)-.gamma.-aminopropyltrimethoxy silane,
N-(p-methoxyphenyl)-.gamma.-aminopropyltriethoxy silane,
N-(p-methoxyphenyl)-.gamma.-aminopropylmethyldimethoxy silane,
N-(p-methoxyphenyl)-.gamma.-aminopropylmethyldiethoxy silane,
N-(p-methoxyphenyl)-.gamma.-aminopropylethyldiethoxy silane,
N-(p-methoxyphenyl)-.gamma.-aminopropylethyldimethoxy silane etc.
The aminosilane coupling agent is particularly preferably
.gamma.-anilinopropyltrimethoxy silane.
[0097] When the silane coupling agent having a secondary amino
group (C) is compounded into the encapsulating epoxy resin molding
material, adhesion of the essential components to arbitrary
components such as fillers is improved, resulting in bringing about
a working effect by which the functions of the essential components
and arbitrary components are preferably exhibited. From the
viewpoint of preferable exhibition of the working effect of the
arbitrary components particularly the inorganic filler (E)
described later, the inorganic filler (E) is added preferably when
the silane coupling agent having a secondary amino group (C) is
used.
[0098] The compounding amount of the silane coupling agent having a
secondary amino group (C) is preferably 0.037 to 4.75% by weight,
more preferably 0.088 to 2.3% by weight, relative to the
encapsulating epoxy resin molding material. When its amount is less
than 0.037% by weight, the disk flow is decreased, and molding
defects such as wire sweep, voids etc. tend to occur easily, and
adhesion to a frame tends to be lowered. When the amount is higher
than 4.75% by weight, the moldability of a package tends to be
lowered.
[0099] When the inorganic filler (E) described later is added, the
compounding amount of the silane coupling agent having a secondary
amino group (C) is 0.05 to 5% by weight, more preferably 0.1 to
2.5% by weight, relative to the inorganic filler (E). The reason
for this definition of the compounding amount is the same as
described above.
[0100] The phosphate (D) used in this invention is not particularly
limited as long as it is an ester of phosphoric acid with an
alcohol compound or a phenol compound, and examples thereof include
trimethyl phosphate, triethyl phosphate, triphenyl phosphate,
tricresyl phosphate, trixylenyl phosphate, cresyldiphenyl
phosphate, xylenyldiphenyl phosphate, tris (2,6-dimethylphenyl)
phosphate, and an aromatic condensed phosphate. From the viewpoint
of hydrolysis resistance, an aromatic condensed phosphate
represented by the following general formula (X) is preferable.
15
[0101] Examples of the phosphate (D) of the formula (X) above
include phosphates shown by the following structural formulae (XI)
to (XV): 16
[0102] The amount of the phosphate (D) added is preferably in the
range of 0.2 to 3.0% by weight in terms of phosphorus atom,
relative to the whole compounding components excluding the filler.
When its amount is less than 0.2% by weight, the disk flow is
decreased, and molding defects such as wire sweep, voids etc. occur
easily. Further, the phosphate (D) has a flame-retardant effect so
that when used also as a flame-retardant, the flame retardant
effect tends to be lowered. When the amount is higher than 3.0% by
weight, moldability and humidity resistance may be lowered, and the
phosphate may bleed out at the time of molding to deteriorate the
outward appearance.
[0103] In this invention, the inorganic filler (E) is preferably
compounded in addition to the components (A), (B) and (C) or (D).
The inorganic filler (E) used in this invention is compounded into
the encapsulating epoxy resin molding material thereby improving
moisture absorption, lowering coefficient of linear expansion,
improving thermal conductivity and improving strength. Examples
thereof include powders, spherical beads, glass fibers etc.
prepared from fused silica, crystalline silica, alumina, zircon,
calcium silicate, calcium carbonate, potassium titanate, silicon
carbide, silicon nitride, aluminum nitride, boron nitride,
beryllia, zirconia, zircon, forsterite, steatite, spinel, mullite,
titania etc. Further, inorganic fillers having a flame retardant
effect include aluminum hydroxide, magnesium hydroxide, zinc
borate, zinc molybdate etc. These inorganic fillers maybe used
singly or in combination thereof. In particular, fused silica is
preferable from the viewpoint of a reduction in coefficient of
linear expansion and alumina is preferable from the viewpoint of
higher thermal conductivity, while the shape of the inorganic
fillers is preferably spherical from the viewpoint of flowability
during molding and abrasion of molds.
[0104] When the inorganic filler (E) is used, its compounding
amount is preferably 75% by weight or more relative to the
encapsulating epoxy resin molding material from the viewpoint of
re-flow resistance. From the viewpoint of improvements in re-flow
resistance, flowability, moldability and strength, the amount is
more preferably 80 to 95% by weight, still more preferably 88 to
92% by weight.
[0105] When the inorganic filler (E) is used, a coupling agent is
preferably compounded into the encapsulating epoxy resin molding
material of the invention in order to improve adhesion of the resin
component to the filler. The coupling agent is preferably the
silane coupling agent having a secondary amino group (C), but if
necessary, other coupling agents can also be used in combination in
such a range as to achieve the effect of the invention. The other
coupling agents which can be used in combination with the silane
coupling agent having a secondary amino group (C) are not
particularly limited as long as they are generally used in
encapsulating epoxy resin molding materials, and examples thereof
include silane compounds having a primary amino group and/or
tertiary amino group, various kinds of silane type compounds such
as epoxysilane, mercaptosilane, alkyl silane, ureidosilane,
vinylsilane etc., titanium type compounds, aluminum chelates,
aluminum/zirconium type compounds etc. Specific examples of these
compounds include silane type coupling agents such as
vinyltrichlorosilane, vinyltriethoxy silane,
vinyltris(.beta.-methoxyethoxy) silane, .gamma.-methacryloxy
propyltrimethoxy silane, .beta.-(3,4-epoxycyclohexyl)
ethyltrimethoxy silane, .gamma.-glycidoxypropyltrimethoxy silane,
.gamma.-glycidoxypropyl- methyldimethoxy silane, vinyltriacetoxy
silane, .gamma.-mercaptopropyltrim- ethoxy silane,
.gamma.-aminopropyltrimethoxy silane,
.gamma.-aminopropylmethyldimethoxy silane,
.gamma.-aminopropyltriethoxy silane,
.gamma.-aminopropylmethyldiethoxy silane, .gamma.-(N,N-dimethyl)
aminopropyltrimethoxy silane, .gamma.-(N,N-diethyl)
aminopropyltrimethoxy silane, .gamma.-(N,N-dibutyl)
aminopropyltrimethoxy silane, .gamma.-(N-methyl)
anilinopropyltrimethoxy silane, .gamma.-(N-ethyl)
anilinopropyltrimethoxy silane,
.gamma.-(N,N-dimethyl)aminopropyltriethox- y silane,
.gamma.-(N,N-diethyl) aminopropyltriethoxy silane,
.gamma.-(N,N-dibutyl) aminopropyltriethoxy silane,
.gamma.-(N-methyl) anilinopropyltriethoxy silane, .gamma.-(N-ethyl)
anilinopropyltriethoxy silane, .gamma.-(N,N-dimethyl)
aminopropylmethyldimethoxy silane, .gamma.-(N,N-diethyl)
aminopropylmethyldimethoxy silane, .gamma.-(N,N-dibutyl)
aminopropylmethyldimethoxy silane, .gamma.-(N-methyl)
anilinopropylmethyldimethoxy silane, .gamma.-(N-ethyl)
anilinopropylmethyldimethoxy silane, N-(trimethoxysilylpropyl)
ethylene diamine, N-(dimethoxymethylsilylisopropyl) ethylene
diamine, methyltrimethoxy silane, dimethyldimethoxy silane,
methyltriethoxy silane, .gamma.-chloropropyltrimethoxy silane,
hexamethyl disilane, vinyltrimethoxy silane and
.gamma.-mercaptopropylmethyl dimethoxy silane;
[0106] and titanate type coupling agents such as
isopropyltriisostearoyl titanate, isopropyl
tris(dioctylpyrophosphate) titanate, isopropyl
tri(N-aminoethyl-aminoethyl) titanate, tetraoctyl
bis(ditridecylphosphite- ) titanate,
tetra(2,2-diallyloxymethyl-1-butyl)bis (ditridecyl) phosphite
titanate, bis(dioctylpyrophosphate) oxyacetate titanate,
bis(dioctylpyrophosphate) ethylene titanate, isopropyltrioctanoyl
titanate, isopropyldimethacryl isostearoyl titanate,
isopropyltridecylbenzenesulfonyl titanate,
isopropylisostearoyldiacryl titanate, isopropyl
tri(dioctylphosphate) titanate, isopropyltricumylphenyl titanate
and tetraisopropyl bis(dioctylphosphite) titanate, and these may be
used singly or in combination thereof.
[0107] When these other coupling agents are used, the amount of the
silane coupling agent having a secondary amino group (C) is
preferably 30% by weight or more, more preferably 50% by weight or
more, relative to the total amount of the coupling agent, in order
to exhibit its performance.
[0108] The total amount of the coupling agent containing the silane
coupling agent having a secondary amino group (C) is preferably
0.037 to 4.75% by weight, more preferably 0.088 to 2.3% by weight,
relative to the encapsulating epoxy resin molding material. When
the amount is less than 0.037% by weight, the adhesion to a frame
tends to be lowered, while when the amount is higher than 4.75% by
weight, the moldability of a package tends to be lowered.
[0109] When the inorganic filler (E) is added, the amount of the
coupling agent compounded is 0.05 to 5% by weight, more preferably
0.1 to 2.5% by weight, relative to the inorganic filler (E). The
reason for this definition of the compounding amount is the same as
described above.
[0110] From the viewpoint of curing properties, the curing promoter
(F) is further incorporated in this invention. The curing promoter
(F) used in this invention is not particularly limited insofar as
it is generally used in encapsulating epoxy resin molding
materials, and examples thereof include cycloamidine compounds such
as 1,8-diaza-bicyclo(5,4,0)undecene-7- ,
1,5-diaza-bicyclo(4,3,0)nonene,
5,6-dibutylamino-1,8-diaza-bicyclo(5,4,0- )undecene-7 etc.,
compounds having intramolecular polarization, comprising the above
compounds to which maleic anhydride, a quinone compound such as
1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone,
2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone,
2,3-dimethoxy-5-methyl-1,4-benzoquinone,
2,3-dimethoxy-1,4-benzoquinone, phenyl-1,4-benzoquinone etc., or a
compound having a n bonding such as diazophenyl methane, phenol
resin etc. has been added, tertiary amines such as
benzyldimethylamine, triethanolamine, dimethylaminoethanol,
tris(dimethylaminomethyl)phenol etc. and derivatives thereof,
imidazoles such as 2-methyl imidazole, 2-phenyl imidazole,
2-phenyl-4-methyl imidazole etc. and derivatives thereof, organic
phosphines such as tributyl phosphine, methyl diphenyl phosphine,
triphenyl phosphine, tris(4-methylphenyl)phosphine, diphenyl
phosphine, phenyl phosphine etc., phosphorus compounds having
intermolecular polarization, comprising maleic anhydride, the
quinone compound, or the compound having a .pi. bonding such as
diazophenyl methane, phenol resin etc. added to the organic
phosphine, and tetraphenyl borates such as tetraphenyl phosphonium
tetraphenyl borate, triphenyl phosphine tetraphenyl borate,
2-ethyl-4-methylimidazole tetraphenyl borate, N-methylmorpholine
tetraphenyl borate etc. and derivatives thereof, and these may used
singly or in combination thereof. Particularly from the viewpoint
of moldability and re-flow resistance, an adduct of organic
phosphine and a quinone compound is preferable.
[0111] Although the amount of the curing promoter compounded is not
particularly limited insofar as the curing promoting effect can be
achieved, the amount is preferably 0.005 to 2% by weight, more
preferably 0.01 to 0.5% by weight, relative to the encapsulating
epoxy resin molding material. When the amount is less than 0.005%
by weight, the resulting material is inferior in curing in a short
time, while when the mount is higher than 2% by weight, the curing
rate is too high thus making preparation of good molded articles
difficult.
[0112] From the viewpoint of preventing occurrence of molding
defects such as wire sweep, voids etc., the disk flow of the
encapsulating epoxy resin molding material of the invention is
preferably 80 mm or more. The disk flow is an indicator of
flowability under a loading of 78 N, and refers to the average of
the measured major axis and minor axis of a molded product produced
by molding 5 g encapsulating epoxy resin molding material under the
conditions of a mold temperature of 180.degree. C., a loading of 78
N, and a curing time of 90 seconds.
[0113] By using the encapsulating epoxy resin molding material
having a disk flow of 80 mm or more, it is possible to reduce
molding defects such as wire sweep and voids even on a
semiconductor device having a semiconductor chip arranged on a
thin, multi-pin, long wire, or narrow pad pitch or on a mounted
substrate.
[0114] The encapsulating epoxy resin molding material of the
invention includes an encapsulating epoxy resin molding material
comprising, as essential components, the epoxy resin (A), the
curing agent (B) and the silane coupling agent having a secondary
amino group (C) or the phosphate (D), and if necessary (E)
inorganic filler and the curing promoter (F).
[0115] The encapsulating epoxy resin molding material of the
invention is used preferably in a semiconductor device having at
least one of the following constitutions (a) to (f):
[0116] (a) at least one of an encapsulating material of an upper
side of a semiconductor chip and an encapsulating material of a
lower side of the semiconductor chip has a thickness 0.7 mm or
less;
[0117] (b) the pin count is 80 or more;
[0118] (c) the length of the wire is 2 mm or more;
[0119] (d) the pad pitch on the semiconductor chip is 90 .mu.m or
less;
[0120] (e) the thickness of a package, in which the semiconductor
chip is disposed on a mounting substrate, is 2 mm or less;
[0121] (f) the area of the semiconductor chip is 25 mm.sup.2 or
more.
[0122] The encapsulating epoxy resin molding material of the
invention can be used in the semiconductors device having at least
one of the above constitutions (a) to (f),particularly preferably
in semiconductor devices having the following constitution.
[0123] From the viewpoint of a reduction in voids, the
encapsulating epoxy resin molding material of the invention is used
preferably in a semiconductor device having the constitution (a) or
(e), more preferably in a semiconductor device having the
constitution (a), still more preferably in a semiconductor device
having the constitution (a) and at least one of the other
constitutions.
[0124] From the viewpoint of a reduction in wire sweep, the
encapsulating epoxy resin molding material of the invention is used
preferably in a semiconductor device having the constitution (b),
(c) or (d), more preferably in a semiconductor device having the
constitution (b), still more preferably in a semiconductor device
having the constitutions (b) and (c) or the constitutions (b) and
(d), particularly preferably in a semiconductor device having the
constitutions (b), (c) and (d).
[0125] From the viewpoint of a reduction in voids and a reduction
in wire sweep, the encapsulating epoxy resin molding material of
the invention is used preferably in a semiconductor device having
the constitutions (a) and (b), the constitutions (a) and (c), the
constitutions (a) and (d), the constitutions (a) and (f), or the
constitutions (c) and (e), more preferably in a semiconductor
device having the constitutions (a), (b) and (d) or the
constitutions (c), (e) and (f), still more preferably in a
semiconductor device having the constitutions (a), (b), (d) and
(f), or the constitutions (a), (b), (c) and (d).
[0126] In a first preferable embodiment of the encapsulating epoxy
resin molding material of the invention, the epoxy resin (A), the
curing agent (B), the silane coupling agent having a secondary
amino group (C), and arbitrary components, that is, the inorganic
filler (E) and other additives, are combined and their amounts are
regulated, whereby the encapsulating epoxy resin molding material
having a disk flow of 80 mm or more can be obtained. Selection of
the epoxy resin (A), the curing agent (B) and the silane coupling
agent having a secondary amino group (C), and the compounding
amount of the inorganic filler (E) if used, are particularly
important.
[0127] In a second preferable embodiment of the encapsulating epoxy
resin molding material of the invention, the epoxy resin (A), the
curing agent (B), the silane coupling agent having a secondary
amino group (C), the inorganic filler (E) and the curing promoter
(F) are combined and their amounts are regulated, whereby the
encapsulating epoxy resin molding material having a disk flow of 80
mm or more can be obtained. Selection of the epoxy resin (A), the
curing agent (B), the silane coupling agent having a secondary
amino group (C) and the curing promoter (F), and the compounding
amount of the inorganic filler (E), are particularly important.
[0128] In a third preferable embodiment of the encapsulating epoxy
resin molding material of the invention, the epoxy resin (A), the
curing agent (B), the phosphate (D), the inorganic filler (E), the
curing promoter (F), and components used as other additives are
combined and their amounts are regulated, whereby the encapsulating
epoxy resin molding material having a disk flow of 80 mm or more
can be obtained. Selection of the epoxy resin (A), the curing agent
(B), the phosphate (D) and the curing promoter (F), and the
compounding amount of the inorganic filler (E), are particularly
important, and the compounding amounts of these components are as
described above.
[0129] The encapsulating epoxy resin molding material of the
invention may, if necessary, incorporate known flame-retardants
such as brominated epoxy resin, antimony trioxide, phosphorus
compounds such as phosphate, red phosphorus etc.,
nitrogen-containing compounds such as melamine, melamine cyanurate,
melamine-modified resin, guanamine-modified phenol resin etc.,
phosphorus/nitrogen-containing compounds such as cyclophosphagen,
and metal compounds such as zinc oxide, iron oxide, molybdenum
oxide, ferrocene etc.
[0130] From the viewpoint of improvements in humidity resistance
and high-temperature resistance of semiconductors such as IC, the
encapsulating epoxy resin molding material of the invention can
also incorporate anion exchangers. The anion exchangers are not
particularly limited, and may be those known in the art, and
examples thereof include hydrotalcite and hydrous oxides of an
element selected from magnesium, aluminum, titanium, zirconium and
bismuth, and these are used singly or in combination thereof. In
particular, the hydrotalcite represented by the following formula
(VIII) is preferable.
Mg.sub.1-XAl.sub.X(OH).sub.2(CO.sub.3).sub.X/2.mH.sub.2O (VIII)
[0131] (0<X.ltoreq.0.5; m is an integer)
[0132] Further, the encapsulating epoxy resin molding material of
the invention can, if necessary, incorporate other additives, for
example releasing agents such as higher fatty acids, higher fatty
acid metal salts, ester type wax, polyolefin type wax,
polyethylene, oxidized polyethylene etc., coloring agents such as
carbon black, and stress-releasing agents such as silicone oil and
silicone rubber powder.
[0133] The encapsulating epoxy resin molding material of the
invention can be prepared by any means which can disperse and mix
the various starting materials, and a method of mixing
predetermined amounts of the starting materials sufficiently in a
mixer, then mixing or melt-kneading the mixture in a mixing roll,
an extruder, a stone mill, a planetary mixer etc., cooling the
mixture, defoaming it if necessary, and grinding it, can be
mentioned as a general means. If necessary, the product may be
formed into tablets having dimensions and weight meeting molding
conditions if necessary.
[0134] The most general method of encapsulating a semiconductor
device with the encapsulating epoxy resin molding material of the
invention is low-pressure transfer molding, but injection molding,
compression molding etc. can also be mentioned. A dispense system,
injection system, printing system etc. may also be used.
[0135] The semiconductor device of this invention includes a
general semiconductor device comprising an active element such as a
semiconductor chip, transistor, diode, thyristor etc. or a passive
element such as capacitor, resistance element, coil etc. installed
on a supporting member such as a lead frame, a wired tape carrier,
a circuit board, glass, a silicon wafer etc. or on a mounted
substrate, wherein an encapsulating epoxy resin molding material
comprising, as essential components, the epoxy resin (A), the
curing agent (B) and the silane coupling agent having a secondary
amino group (C) or the phosphate (D), and if necessary (E)
inorganic filler and the curing promoter (F) is used as an
encapsulating material.
[0136] The mounted substrate is not particularly limited, and
include e.g. an interposer substrate such as organic substrate,
organic film, ceramic substrate, glass substrate etc., a glass
substrate for liquid crystal, a substrate for MCM (multi chip
module), a substrate for hybrid IC, etc.
[0137] Preferably, the semiconductor device of the invention
further has at least one of the following constitutions (a) to
(f):
[0138] (a) at least one of an encapsulating material of an upper
side of a semiconductor chip and an encapsulating material of a
lower side of the semiconductor chip has a thickness 0.7 mm or
less;
[0139] (b) the pin count is 80 or more;
[0140] (c) the length of the wire is 2 mm or more;
[0141] (d) the pad pitch on the semiconductor chip is 90 .mu.m or
less;
[0142] (e) the thickness of a package, in which the semiconductor
chip is disposed on a mounting substrate, is 2 mm or less;
[0143] (f) the area of the semiconductor chip is 25 mm.sup.2 or
more.
[0144] Out of the semiconductor devices having at least one of the
constitutions (a) to (f) described above, those semiconductor
devices having the following constitution are particularly
preferable from the viewpoint of a higher effect of the
invention.
[0145] From the viewpoint of a higher effect on reduction in voids,
the semiconductor device is preferably a semiconductor device
having the constitution (a) or (e), more preferably a semiconductor
device having the constitution (a), still more preferably a
semiconductor device having the constitution (a) and at least one
of the other constitutions.
[0146] From the viewpoint of a higher effect on reduction in wire
sweep, the semiconductor device is preferably a semiconductor
device having the constitution (b), (c) or (d), more preferably a
semiconductor device having the constitution (b), still more
preferably a semiconductor device having the constitutions (b) and
(c) or the constitutions (b) and (d), particularly preferably a
semiconductor device having the constitutions (b), (c) and (d).
[0147] From the viewpoint of a higher effect on reduction in voids
and wire sweep, the semiconductor device is preferably a
semiconductor device having the constitutions (a) and (b), the
constitutions (a) and (c), the constitutions (a) and (d), the
constitutions (a) and (f), or the constitutions (c) and (e), more
preferably a semiconductor device having the constitutions (a), (b)
and (d) or the constitutions (c), (e) and (f), still more
preferably a semiconductor device having the constitutions (a),
(b), (d) and (f), or the constitutions (a), (b), (c) and (d).
[0148] Such semiconductor devices include, for example, resin
encapsulating type IC such as DIP (dual inline package), PLCC
(plastic leaded chip carrier), QFP (quad flat package), SOP (small
outline package), SOJ (small outline J-lead package), TSOP (thin
small outline package), TQFP (thin quad flat package) etc.,
produced by fixing an element such as semiconductor chip on a lead
frame (island tab), connecting a terminal (e.g. a bonding pad) of
the element to the lead by wire bonding or bumping, and then
encapsulating the semiconductor chip by transfer molding with the
encapsulating epoxy resin molding material of the invention; TCP
(tape carrier package) wherein a semiconductor chip lead-bonded
onto a tape carrier was encapsulated with the encapsulating epoxy
resin molding material of the invention; COB (chip on board)
wherein a semiconductor chip connected by wire bonding, flip chip
bonding or a solder to a wire formed on a circuit board or glass
was encapsulated with the encapsulating epoxy resin molding
material of the invention; a semiconductor device such as COG (chip
on glass) having a bare chip mounted thereon; hybrid IC wherein an
active element such as semiconductor chip, transistor, diode,
thyristor etc. and/or a passive element such as capacitor,
resistance element, coil etc., connected by wire bonding, flip chip
bonding, a solder etc. to a wire formed on a circuit board or
glass, was encapsulated with the encapsulating epoxy resin molding
material of the invention; BGA (ball grid array) produced by
installing a semiconductor chip on an interposer substrate having a
terminal for connection to a MCM (multi chip module) mother board,
then connecting the semiconductor chip by bumping or wire bonding
to a wire formed on the interposer substrate and then encapsulating
the semiconductor-installed side with the encapsulating epoxy resin
molding material of the invention; CSP (chip size package); MCP
(multi chip Package) etc. The semiconductor device may be a stacked
package having two or more laminated elements installed on a
mounted substrate or a mold array package having two or more
elements encapsulated all at once with the encapsulating epoxy
resin molding material.
[0149] FIG. 1 shows one example of the semiconductor device of the
invention, but the semiconductor device of the invention is not
limited thereto. FIG. 1 shows QFP produced by fixing a
semiconductor chip 3 via a die bond 2 onto an island (tab) 1, then
connecting a terminal (bonding pad) of the semiconductor chip 3 to
a lead pin 4 via a wire 5 (wire bonding) and encapsulating the
semiconductor chip with an encapsulating epoxy resin molding
material (encapsulating material) 6, and FIG. 1 (a) is a sectional
view, (b) is a top view (partially perspective view), (c) is a top
view (partially perspective view) of the enlarged terminal (bonding
pad) 7 on the semiconductor chip 3.
[0150] The semiconductor device of the invention shown in FIG. 1 is
preferably a thin semiconductor device wherein the thickness a of
the encapsulating material 6 on the upper side of the semiconductor
chip and/or the thickness b of the encapsulating material 6 on the
lower side of the semiconductor chip is 0.7 mm or less, and may be
0.5 mm or less or 0.3 mm or less. The thickness of the package
(total thickness of the semiconductor device) c is preferably 2.0
mm or less, more preferably 1.5 mm or less, and may be 1.0 mm or
less.
[0151] The area d of the semiconductor chip is preferably 25
mm.sup.2 or more and may be 50 mm.sup.2 or more, or 80 mm.sup.2 or
more.
[0152] The semiconductor device is preferably a multi-pin type
semiconductor device wherein the pin count 4 is 80 or more, and may
be 100 or more or 200 or more.
[0153] The length of the wire for connecting the semiconductor chip
to the lead pin is preferably 2 mm or more, and may be 3 mm or
more, or 5 mm or more.
[0154] The pitch e between bonding pads on the semiconductor chip
is preferably 90 .mu.m or less, and may be 80 .mu.m or less, or 60
.mu.m or less.
[0155] FIG. 3 and FIG. 5 show other examples of the semiconductor
device of the invention, but the semiconductor device of the
invention is not limited thereto. An element having the same
function as in FIG. 1 is given the same symbol and its description
is omitted.
[0156] FIG. 3 shows BGA produced by fixing a semiconductor chip 3
via a die attach 2 onto an insulating base substrate 8, then
connecting a terminal (bonding pad) of the semiconductor chip 3 to
a terminal on the circuit board via a wire 5 (by wire bonding) and
encapsulating the semiconductor chip with an encapsulating epoxy
resin molding material (encapsulating material) 6, and (a) shows a
sectional view, (b) is a partially perspective, top view, and (c)
is an enlarged view of the bonding pad. In FIG. 3, 9 is a solder
ball.
[0157] In the semiconductor device shown in FIG. 3, the thickness a
of the package is preferably 2 mm or less, and may be 1.5 mm or
less, or 1.0 mm or less.
[0158] The area d of the semiconductor chip is preferably 25
mm.sup.2 or more, and may be 50 mm.sup.2 or more, or 80 mm.sup.2 or
more.
[0159] The length of the wire 5 for connecting the semiconductor
chip to the lead pin is preferably 2 mm or more, and may be 3 mm or
more, or 5 mm or more.
[0160] The pitch e between bonding pads on the semiconductor chip
is preferably 90 .mu.m or less, and may be 80 .mu.m or less, or 60
.mu.m or less.
[0161] FIG. 5 shows mold array package type stacked BGA, and (a) is
a top view (partially perspective view), and (b) is a partially
enlarged, sectional view. In FIG. 5, 9 is a solder ball.
[0162] The semiconductor device shown in FIG. 5 should be a
semiconductor device wherein the thickness a of the package is 2 mm
or less, and the thickness of the package may be 1.5 mm or less, or
1.0 mm or less.
[0163] By encapsulating a semiconductor device with the
semiconductor encapsulating epoxy resin molding material of the
invention, it is possible to reduce molding defects such as wire
sweep and voids even on a thin semiconductor having the thickness
of the encapsulating material described above, on a semiconductor
device having the thickness of the encapsulating material described
above and the area of the semiconductor chip described above, and a
semiconductor device having the number of pins, the length of the
wire and the pad pitch described above.
[0164] Hereinafter, this invention is described by Examples, which
however are not intended to limit the scope of this invention.
EXAMPLES I-1 to I-5 COMPARATIVE EXAMPLES I-1 to I-15
[0165] (A-I) Preparation of Encapsulating Epoxy Resin Molding
Materials
[0166] Epoxy resins such as a biphenyl type epoxy resin having an
epoxy equivalent of 196, a melting point of 106.degree. C. and a
melt viscosity (ICI viscosity) at 150.degree. C. of 0.1 poise
(trade name: Epicoat YX-4000H, manufactured by Yuka Shell Epoxy
Co., Ltd.), a bisphenol F type epoxy resin having an epoxy
equivalent of 186, a melting point of 75.degree. C. and a melt
viscosity (ICI viscosity) at 150.degree. C. of 0.1 poise (trade
name: YSLV-80XY, manufactured by Nippon Steel Chemical Co., Ltd.),
a stilbene type epoxy resin having an epoxy equivalent of 210, a
melting point of 120.degree. C. and a melt viscosity (ICI
viscosity) at 150.degree. C. of 0.1 poise (trade name: ESLV-210,
manufactured by Sumitomo Chemical Co., Ltd.), an o-cresol novolak
type epoxy resin having an epoxy equivalent of 195, a softening
point of 65.degree. C. and a melt viscosity (ICI viscosity) at
150.degree. C. of 2.0 poises (trade name: ESCN-190, manufactured by
Sumitomo Chemical Co., Ltd.) and an bisphenol A type brominated
epoxy resin having an epoxy equivalent of 375, a softening point of
80.degree. C., a melt viscosity (ICI viscosity) at 150.degree. C.
of 1.3 poises and a bromine content of 48% by weight (trade name:
ESB-400T, manufactured by Sumitomo Chemical Co., Ltd.);
[0167] curing agents such as a phenol-aralkyl resin having a
softening point of 70.degree. C., a hydroxyl equivalent of 175 and
a melt viscosity (ICI viscosity) at 150.degree. C. of 2.0 poises
(trade name: Milex XL-225, manufactured by Mitsui Chemicals, Inc.),
a biphenyl type phenol resin having a softening point of 80.degree.
C., a hydroxyl equivalent of 199 and a melt viscosity (ICI
viscosity) at 150.degree. C. of 1.4 poises (trade name: MEH-7851,
manufactured by Meiwa Plastic Industries, Ltd.) and a phenol
novolak resin having a softening point of 80.degree. C., a hydroxyl
equivalent of 106 and a melt viscosity (ICI viscosity) at
150.degree. C. of 1.8 poises (trade name: H-1, manufactured by
Meiwa Plastic Industries, Ltd.)
[0168] a curing accelerator such as triphenyl phosphine;
[0169] coupling agents such as .gamma.-anilinopropyl
trimethoxysilane (secondary amino silane), .gamma.-aminopropyl
trimethoxysilane (primary amino silane),
.gamma.-(N-methyl)anilinopropyl trimethoxysilane (tertiary amino
silane) and .gamma.-glycidoxypropyltrimethoxy silane (epoxy
silane);
[0170] an inorganic filler of spherical fused silica having an
average particle diameter of 17.5 .mu.m and a specific surface area
of 3.8 m.sup.2/g;
[0171] and other additives such as antimony trioxide, carnauba wax
(manufactured by K.K. Serarika NODA) and carbon black (trade name:
MA-100, manufactured by Mitsubishi Chemical Corporation) were
compounded in the amounts "part by weight" shown in Table 1 and
then kneaded with rolls at a kneading temperature of 80.degree. C.
for a kneading time of 10 minutes, to prepare encapsulating epoxy
resin molding materials I-1 to I-10 (I-6 to I-10 are Comparative
Examples).
1TABLE 1 Compositions of encapsulating epoxy resin molding
materials (parts by weight) Encapsulating epoxy resin molding
materials I Components 1 2 3 4 5 6 7 8 9 10 Biphenyl type epoxy
resin 85 85 -- -- -- 85 85 85 85 -- Bisphenol F type epoxy resin --
-- 85 -- -- -- -- -- -- -- Stilbene type epoxy resin -- -- -- 85 --
-- -- -- -- -- o-Cresol novolak type epoxy resin -- -- -- -- 85 --
-- -- -- 85 Brominated epoxy resin 15 15 15 15 15 15 15 15 15 15
Phenol-aralkyl resin 83 -- 87 78 -- 83 83 83 -- -- Biphenyl phenol
resin -- 94 -- -- -- -- -- -- 94 -- Phenol novolak resin -- -- --
-- 50 -- -- -- -- 50 Curing accelerator 3.5 3.5 3.5 3.5 3.5 3.5 3.5
3.5 3.5 3.5 Secondary amino silane 4.5 4.5 4.5 4.5 4.5 -- -- -- --
-- Primary amino silane -- -- -- -- -- -- -- 4.5 -- -- Tertiary
amino silane -- -- -- -- -- -- 4.5 -- -- -- Epoxy silane -- -- --
-- -- 4.5 -- -- 4.5 4.5 Fused silica 1507 1593 1538 1469 737 1507
1507 1507 1593 737 Antimony trioxide 6.0 6.0 6.0 6.0 6.0 6.0 6.0
6.0 6.0 6.0 Carnauba wax 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0
Carbon wax 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 Amount of
inorganic filler 88 88 88 88 81 88 88 88 88 81 (weight-%)
TEST EXAMPLE 1
[0172] The characteristics of the encapsulating epoxy resin molding
materials (I-1) to (I-10) prepared above were examined in the
following tests. The results are shown in Table 2.
[0173] (1) Spiral Flow
[0174] The encapsulating epoxy resin molding material was molded
with a mold for measuring spiral flow according to EMMI-1-66 by a
transfer molding machine at a mold temperature of 180.degree. C.,
at a molding pressure of 6.9 MPa for a curing time of 90 seconds,
and then the distance of flow (cm) was determined.
[0175] (2) Disk Flow
[0176] Using a disk flow-measuring flat mold having an upper mold
of 200 mm (W).times.200 mm (D).times.25 mm (H) and a lower mold of
200 mm (W).times.200 mm (D).times.15 mm (H), the weighed sample
(encapsulating epoxy resin molding material) 5 g, was placed on the
center of the lower mold heated at 180.degree. C.; and 5 seconds
later, the upper mold heated at 180.degree. C. was closed; and the
sample was compression-molded under a loading of 78 N for a curing
time of 90 seconds; and the major axis (mm) and the minor axis (mm)
of the molded product were measured with calipers, and their
average value (mm) was determined as disk flow.
2TABLE 2 Characteristics of the encapsulating epoxy resin molding
materials Character- Encapsulating epoxy resin molding materials I
istics 1 2 3 4 5 6 7 8 9 10 Spiral 107 112 115 113 113 89 94 --* 90
85 flow (cm) Disk flow 83 87 92 90 89 73 75 --* 76 70 (mm) *The
encapsulating epoxy resin molding material I-8 could not be
measured due to gelation.
[0177] (B-I) Preparation of Semiconductor Devices
[0178] Using the encapsulating epoxy resin molding materials I-1 to
I-10, the semiconductor devices in Examples I-1 to I-5 and
Comparative Examples I-1 to I-15 were prepared. Encapsulation in
the encapsulating epoxy resin molding material was carried out by
molding at a mold temperature of 180.degree. C., at a molding
pressure of 6.9 MPa for a curing time of 90 seconds in a transfer
molding machine, followed by post-curing at 180.degree. C. for 5
hours.
[0179] Using the encapsulating epoxy resin molding materials I-1 to
I-5, the thin, multi-pin, long wire and narrow-pad-pitch
semiconductor devices in Examples I-1 to I-5 (100-pin LQFP) having
100 lead pins and an external dimension of 20 mm.times.20 mm and a
total thickness of 1.5 mm, mounted with a test silicone chip of 10
mm.times.10 mm.times.0.4 mm (area 100 mm.sup.2) with a bonding pad
pitch of 80 .mu.m, subjected to wire bonding with a wire of 18
.mu.m in diameter and 3 mm in length and having the encapsulating
material of 0.5 mm in thickness on the upper side of the
semiconductor chip and the encapsulating material of 0.5 mm in
thickness on the lower side of the semiconductor chip, were
prepared.
[0180] Using the encapsulating epoxy resin molding materials I-6 to
I-10, the thin, multi-pin, long wire and narrow-pad-pitch
semiconductor devices in Comparative Examples I-1 to I-5 (100-pin
LQFP) with 100 lead pins were prepared in the same manner as in
Examples I-1 to I-5.
[0181] Using the encapsulating epoxy resin molding materials I-1 to
I-10, the semiconductor devices in Comparative Examples I-6 to I-16
(64-pin QFP-1H) having 64 lead pins and an external dimension of 20
mm.times.20 mm and a total thickness of 2.7 mm, mounted with a test
silicone chip of 4 mm.times.4 mm.times.0.4 mm (area 16 mm.sup.2)
with a bonding pad pitch of 100 .mu.m, subjected to wire bonding
with a wire of 18 .mu.m in diameter and 1.5 mm in length and having
the encapsulating material of 1.1 mm in thickness on the upper side
of the semiconductor chip and the encapsulating material of 1.1 mm
in thickness on the lower side of the semiconductor chip, were
prepared. TEST EXAMPLE 2
[0182] The prepared semiconductor devices in Examples I-1 to I-5
and Comparative Examples I-1 to I-15 were evaluated by the
following tests. The evaluation results are shown in Tables 3 and
4.
[0183] (1) Wire Sweep (Indicator of Wire Sweep)
[0184] Using a soft-X-ray measuring device (PRO-TEST 100 type,
manufactured by Softex Co., Ltd.), the semiconductor device was
examined for Wire sweep by fluroscopic observation at a voltage of
100 kV at a current of 1.5 mA, to evaluate wire sweep. As shown in
FIGS. 2 or 4, the observation was carried in a direction
perpendicular to the frame surface, and the minimum distance L of
the wire bonding (that is, the distance between the terminal 7 of
the semiconductor chip 3 and the lead pin 4 or the bonded region of
the terminal 10 on the wiring board) and the maximum deformation X
of the wire 5 were measured, and X/L.times.100 was calculated as
wire deformation (%).
[0185] (2) Void Generation
[0186] The X-ray examination of the semiconductor device was
carried out in the same manner as in (1) above, and whether voids
of 0.1 mm or more in diameter had been generated or not was
observed, and void generation was evaluated in terms of the number
of semiconductor devices with voids/the number of test
semiconductor devices.
3TABLE 3 Evaluation result 1 of the semiconductor devices Examples
I Comparative Examples I Characteristics 1 2 3 4 5 1 2 3 4 5
Encapsulating epoxy resin molding 1 2 3 4 5 6 7 8 9 10 materials I
Wire sweep (%) 5 3 2 2 2 14 11 not 12 18 Void generation 0/20 0/20
0/20 0/20 0/20 4/20 3/20 moldable 2/20 5/20
[0187]
4TABLE 4 Evaluation result 2 of the semiconductor devices Examples
I Comparative Examples I Characteristics 6 7 8 9 10 11 12 13 14 15
Encapsulating epoxy resin molding 1 2 3 4 5 6 7 8 9 10 materials I
Wire sweep (%) 0 0 0 0 0 5 3 not 4 7 Void generation 0/20 0/20 0/20
0/20 0/20 0/20 0/20 moldable 0/20 0/20
[0188] The thin, multi-pin, long wire and narrow-pad-pitch
semiconductor devices in Comparative Examples I-1 to I-5, which had
been encapsulated in the encapsulating epoxy resin molding
materials I-6 to I-10 containing neither the silane coupling agent
having a secondary amino group (C) nor the phosphate (D), generated
the molding defect of either wire sweep (high wire deformation) and
void generation or a molding inability due to gelation.
[0189] On the other hand, the encapsulating epoxy resin molding
materials I-1 to I-5 containing the epoxy resin (A), the curing
agent (B) and the silane coupling agent having a secondary amino
group (C) were excellent in fluidity, and the thin, multi-pin, long
wire and narrow-pad-pitch semiconductor devices in Examples I-1 to
I-5, which had been encapsulated therein, were excellent in
moldability with no wire sweep(minimum wire deformation) without
generating voids.
[0190] The semiconductor devices in Comparative Examples I-6 to
I-15, wherein the constitution of the semiconductor, with respect
to the thickness of the encapsulating material, the length of the
wire, the pin count, the pitch of pads, the thickness of the
package, etc., was outside of the range defined in this invention,
were excellent in moldability with no wire sweep(minimum wire
deformation) without generating voids, except for the molding
inability due to gelation in Comparative Example I-13 using
encapsulation in the comparative encapsulating epoxy resin molding
material I-8 containing a primary amino silane coupling agent in
place of the silane coupling agent containing a secondary amino
group.
EXAMPLES II-1 to II-10 COMPARATIVE EXAMPLES II-1 to II-30
[0191] (B-II) Preparation of Semiconductor Devices
[0192] Using the encapsulating epoxy resin molding materials I-1 to
I-10, the semiconductor devices in Examples II-1 to II-10 and
Comparative Examples II-1 to II-30 were prepared. Encapsulation in
the encapsulating epoxy resin molding material was carried out by
molding at a mold temperature of 180.degree. C., at a molding
pressure of 6.9 MPa for a curing time of 90 seconds in a transfer
molding machine, followed by post-curing at 180.degree. C. for 5
hours.
[0193] Preparation of OMPAC Type BGA
[0194] The semiconductor devices (OMPAC type BGA) having a package
thickness of 1.5 mm in Examples II-1 to II-5 were prepared in the
following manner.
[0195] An insulating base substrate (glass cloth-epoxy resin
laminated plate available under the trade name E-679, manufactured
by Hitachi Chemical Co., Ltd.) was provided with a fine wiring
pattern, then coated with an insulating protective resist (trade
name: PSR4000AUS5, manufactured by TAIYO INK MFG. CO. LTD.) on the
surface thereof, except for metal-plated terminals at a
semiconductor chip-mounting side and external connecting terminals
at its opposite side, and dried at 120.degree. C. for 2 hours. The
resulting semiconductor chip-mounting substrate having an external
dimension of 26.2 mm.times.26.2 mm.times.0.6 mm thickness was
coated with an adhesive (trade name: EN-X50, manufactured by
Hitachi Chemical Co., Ltd.), then mounted with a semiconductor chip
having a chip size of 9 mm.times.9 mm.times.0.51 mm thickness (area
81 mm.sup.2) and a pad pitch of 80 .mu.m. The semiconductor
chip-mounting substrate was then heated at a predetermined rate of
increasing temperature from room temperature to 180.degree. C. in 1
hour in a clean oven, further heated at 180.degree. C. for 1 hour
and subjected to wire bonding with a metal wire of 30 .mu.m in
diameter and 5 mm in length. Then the encapsulating epoxy resin
molding materials I-1 to I-5 were transfer-molded to a dimension of
26.2 mm.times.26.2 mm.times.0.9 mm thickness on the semiconductor
chip-mounted surface under the conditions described above.
[0196] Using the semiconductor epoxy resin molding materials I-6 to
I-10, the semiconductor devices (OMPAC type BGA) having a package
thickness of 1.5 mm in Comparative Examples 1 to 5 were prepared in
the same manner as in Examples II-1 to II-5.
[0197] The semiconductor devices (OMPAC type BGA) having a package
thickness of 2.5 mm in Comparative Examples II-6 to II-15 were
prepared by transfer-molding the encapsulating epoxy resin molding
materials 1 to 10 to a dimension of 26.2 mm.times.26.2 mm.times.1.9
mm thickness on the semiconductor chip-mounted surface under the
above-described conditions in the same manner as in Examples II-1
to II-5, except that a semiconductor chip having a chip size of 4
mm.times.4 mm.times.0.51 mm thickness (area 16 mm.sup.2) and a pad
pitch of 100 .mu.m, and a metal wire of 30 .mu.m in diameter and
1.5 mm in length, were used.
[0198] Preparation of Mold Array Package Type Stacked BGA
[0199] The semiconductor devices (mold array package type stacked
BGA) having a package thickness of 0.95 mm in Examples II-6 to
II-10 were prepared in the following manner.
[0200] Two semiconductor chips having a chip size of 9.7
mm.times.6.0 mm.times.0.4 mm thickness (area 58 mm.sup.2) and a pad
pitch of 80 .mu.m, having a die attach film (trade name: DF-400,
manufactured by Hitachi Chemical Co., Ltd.) applied on the back
thereof, were layered and arranged on a polyimide substrate of
length 48 mm.times.width 171 mm.times.thickness 0.15 mm, as shown
in FIG. 2. The semiconductor chip-mounting substrate was then
contact-bonded at a contact-bonding pressure of 200.degree. C.
under a loading of 1.96 N for a contact-bonding time of 10 seconds;
further baked at 180.degree. C. for 1 hour, and then subjected to
wire-bonding with a metal wire of 30 .mu.m in diameter and 5 mm in
length, followed by transfer-molding the encapsulating epoxy resin
molding materials I-1 to I-5 to a dimension of length 40
mm.times.width 83 mm.times.thickness 0.8 mm on the surface mounted
with the semiconductor chips under the conditions described
above.
[0201] Using the semiconductor epoxy resin molding materials I-6 to
I-10, the semiconductor devices (mold array package type stacked
BGA) having a package thickness of 0.95 mm in Comparative Examples
II-16 to II-20 were prepared in the same manner as in Examples II-6
to II-10.
[0202] Further, the semiconductor devices (mold array package type
stacked BGA) having a package thickness of 2.65 mm in Comparative
Examples II-21 to II-30 were prepared by transfer-molding the
encapsulating epoxy resin molding materials I-1 to I-10 to a
dimension of length 40 mm.times.width 83 mm.times.thickness 2.5 mm
on the surface mounted with semiconductor chips under the
above-described conditions in the same manner as in Examples II-6
to II-10, except that semiconductor chips having a chip size of 5.1
mm.times.3.1 mm.times.0.4 mm thickness (area 16 mm.sup.2) and a pad
pitch of 100 .mu.m, and a metal wire of 30 .mu.m in diameter and
1.5 mm in length, were used.
[0203] The prepared semiconductor devices in Examples II-1 to II-10
and Comparative Examples II-1 to II-30 were evaluated for (1) wire
sweep (indicator of wire sweep) and (2) the number of generated
voids by the test method 2 described above. The evaluation results
are shown in Tables 5 to 8.
5TABLE 5 Evaluation result 1 of the semiconductor devices Examples
II Comparative Examples II Characteristics 1 2 3 4 5 1 2 3 4 5
Encapsulating epoxy resin molding 1 2 3 4 5 6 7 8 9 10 materials I
Wire sweep (%) 7 5 3 4 3 16 15 Not 14 20 Void generation 0/20 0/20
0/20 0/20 0/20 5/20 4/20 moldable 3/20 7/20
[0204]
6TABLE 6 Evaluation result 2 of the semiconductor devices
Comparative Examples II Characteristics 6 7 8 9 10 11 12 13 14 15
Encapsulating epoxy resin molding 1 2 3 4 5 6 7 8 9 10 materials I
Wire sweep (%) 2 1 0 0 1 7 6 Not 4 8 Void generation 0/20 0/20 0/20
0/20 0/20 0/20 0/20 moldable 0/20 3/20
[0205]
7TABLE 7 Evaluation result 3 of the semiconductor devices Examples
II Comparative Examples II Characteristics 6 7 8 9 10 16 17 18 19
20 Encapsulating epoxy resin molding 1 2 3 4 5 6 7 8 9 10 materials
I Wire sweep (%) 8 7 6 6 6 18 17 Not 15 22 Void generation 0/20
0/20 0/20 0/20 0/20 8/20 6/20 moldable 5/20 9/20
[0206]
8TABLE 8 Evaluation result 4 of the semiconductor devices
Comparative Examples II Characteristics 21 22 23 24 25 26 27 28 29
30 Encapsulating epoxy resin molding 1 2 3 4 5 6 7 8 9 10 materials
I Wire sweep (%) 3 3 2 2 2 9 7 Not 6 9 Void generation 0/20 0/20
0/20 0/20 0/20 0/20 0/20 moldable 0/20 2/20
[0207] The thin semiconductor devices in Comparative Examples II-1
to II-5 and Comparative Examples II-16 to II-20, which had been
encapsulated in the encapsulating epoxy resin molding materials I-6
to I-10 containing neither the silane coupling agent having a
secondary amino group (C) nor the phosphate (D), generated the
molding defect of either wire sweep (high wire deformation) and
void generation or a molding inability due to gelation.
[0208] On the other hand, the encapsulating epoxy resin molding
materials II-1 to II-5 containing the epoxy resin (A), the curing
agent (B) and the silane coupling agent having a secondary amino
group (C) were excellent in fluidity, and the thin semiconductor
devices in Examples II-1 to II-10, which had been encapsulated
therein, were excellent in moldability with no wire sweep(minimum
wire deformation) without generating voids.
[0209] The semiconductor devices in Comparative Examples II-6 to
II-15 and Comparative Examples II-21 to II-30, wherein the
thickness of the package was outside of the range defined in this
invention, were excellent in moldability with no wire sweep(minimum
wire deformation) without generating voids, except for the molding
inability due to gelation in Comparative Example II-13 and II-28
using encapsulation in the comparative encapsulating epoxy resin
molding material 8 containing a primary amino silane coupling agent
in place of the silane coupling agent containing a secondary amino
group.
EXAMPLES III-1 to III-9 COMPARATIVE EXAMPLES III-1 to III-4
[0210] (A-III) Preparation of Encapsulating Epoxy Resin Molding
Materials
[0211] The respective components shown below were compounded in the
amounts (parts by weight) shown in Table 13 and kneaded with rolls
at a kneading temperature of 80.degree. C. for a kneading time of
10 minutes to prepare encapsulating epoxy resin molding materials
III-1 to III-9 (Examples III-1 to III-9) and molding materials
III-10 to III-13 (Comparative Examples III-1 to III-4).
[0212] (A) Epoxy Resin
[0213] (A-1) A biphenyl type epoxy resin having an epoxy equivalent
of 196, a melting point of 106.degree. C. and a melt viscosity (ICI
viscosity) at 150.degree. C. of 0.1.times.10.sup.-1 Pas (trade
name: Epicoat YX-4000H, manufactured by Yuka Shell Epoxy Co.,
Ltd.)
[0214] (A-2) A bisphenol F type epoxy resin having an epoxy
equivalent of 186, a melting point of 75.degree. C. and a melt
viscosity (ICI viscosity) at 150.degree. C. of 0.1.times.10.sup.-1
Pas (trade name: YSLV-80XY, manufactured by Nippon Steel Chemical
Co., Ltd.)
[0215] (A-3) A stilbene type epoxy resin having an epoxy equivalent
of 210, a melting point of 120.degree. C. and a melt viscosity (ICI
viscosity) at 150.degree. C. of 0.1.times.10.sup.-1 Pas (tradename:
ESLV-210, manufactured by Sumitomo Chemical Co., Ltd.)
[0216] (A-4) An o-cresol novolak type epoxy resin having an epoxy
equivalent of 195, a softening point of 65.degree. C. and a melt
viscosity (ICI viscosity) at 150.degree. C. of 2.0.times.10.sup.-1
Pas (trade name: ESCN-190, manufactured by Sumitomo Chemical Co.,
Ltd.)
[0217] (A-5) An bisphenol A type brominated epoxy resin having an
epoxy equivalent of 375, a softening point of 80.degree. C., a melt
viscosity (ICI viscosity) at 150.degree. C. of 1.3.times.10.sup.-1
Pas and a bromine content of 48% by weight (trade name: ESB-400T,
manufactured by Sumitomo Chemical Co., Ltd.)
[0218] (B) Curing Agent
[0219] (B-1) A phenol-aralkyl resin having a softening point of
70.degree. C., a hydroxyl equivalent of 175 and a melt viscosity
(ICI viscosity) at 150.degree. C. of 2.0.times.10.sup.-1 Pas (trade
name: Milex XL-225, manufactured by Mitsui Chemicals, Inc.)
[0220] (B-2) A biphenyl type phenol resin having a softening point
of 80.degree. C., a hydroxyl equivalent of 199 and a melt viscosity
(ICI viscosity) at 150.degree. C. of 1.4.times.10.sup.-1 Pas (trade
name: MEH-7851, manufactured by Meiwa Plastic Industries, Ltd.)
[0221] (B-3) A phenol novolak resin having a softening point of
80.degree. C., a hydroxyl equivalent of 106 and a melt viscosity
(ICI viscosity) at 150.degree. C. of 1.8.times.10.sup.-1 Pas (trade
name: H-1, manufactured by Meiwa Kasei Co., Ltd.)
[0222] (B-4) A melamine phenol resin having a softening point of
81.degree. C., a hydroxyl equivalent of 120 and a melt viscosity
(ICI viscosity) at150.degree. C. of 2.0.times.10.sup.-1 Pas (trade
name: Phenolite KA-7052-L2, manufactured by Dainippon Ink and
Chemicals, Incorporated)
[0223] (D) Phosphate
[0224] (D-1) Aromatic condensed phosphate (trade name: PX-200,
manufactured by Daihachi Chemical Industry Co., LTD)
[0225] (D-2) Triphenyl phosphate
[0226] (E) Inorganic Filler
[0227] (E- 1) Spherical fused silica having an average particle
diameter of 17.5 .mu.m and a specific surface area of 3.8
m.sup.2/g
[0228] (F) Curing Accelerator
[0229] (F-1) Triphenyl phosphine
[0230] (G) Coupling Agent
[0231] (G-1) .gamma.-Glycidoxypropyl trimethoxy silane (epoxy
silane)
[0232] (H) Flame-Retardant
[0233] (H-1) Composite metal hydroxide (trade name: Echomug Z-10,
manufactured by Tateho Chemical Industries Co., LTD)
[0234] (I) Other Additives
[0235] (I-1) Antimony trioxide
[0236] (I-2) Carnauba wax (manufactured by K.K. Serarika NODA)
[0237] (I-3) Carbon black (trade name: MA-100, manufactured by
Mitsubishi Chemical Corporation)
9TABLE 9 Molding Material No. III 1 2 3 4 5 6 7 8 9 10 11 12 13
Comparative Examples Compounding Examples III III Components 1 2 3
4 5 6 7 8 9 1 2 3 4 (A-1) 100 100 100 100 100 -- -- -- 85 100 100
85 -- (parts by weight) (A-2) -- -- -- -- -- 100 -- -- -- -- -- --
-- (parts by weight) (A-3) -- -- -- -- -- -- 100 -- -- -- -- -- --
(parts by weight) (A-4) -- -- -- -- -- -- -- 100 -- -- -- -- 85
(parts by weight) (A-5) -- -- -- -- -- -- -- -- 15 -- -- 15 15
(parts by weight) (B-1) 89 80 89 89 -- 94 83 -- 83 89 89 83 --
(parts by weight) (B-2) -- -- -- -- 102 -- -- -- -- -- -- -- --
(parts by weight) (B-3) -- -- -- -- -- -- -- 54 -- -- -- -- 50
(parts by weight) (B-4) -- 6 -- -- -- -- -- -- -- -- -- -- --
(parts by weight) (D-1) 25 25 -- 10 25 25 25 40 10 -- -- -- --
(parts by weight) (D-2) -- -- 24 -- -- -- -- -- -- -- -- -- --
(parts by weight) (E-1) 1713 1690 1706 1570 1805 1749 1668 899 1582
1525 1425 1477 724 (parts by weight) (F-1) 3.5 3.5 3.5 3.5 3.5 3.5
3.5 2 3.5 3.5 3.5 3.5 2 (parts by weight) (G-1) 4.5 4.5 4.5 4.5 4.5
4.5 4.5 3 4.5 4.5 4.5 4.5 3 (parts by weight) (H-1) -- -- -- 30 --
-- -- -- -- -- 100 -- -- (parts by weight) (I-1) -- -- -- -- -- --
-- -- 6 -- -- -- 6 (parts by weight) (I-2) 2 2 2 2 2 2 2 2 2 2 2 2
2 (parts by weight) (I-3) 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5 3.5
3.5 3.5 3.5 (parts by weight) (E-1) 88 88 88 88 88 88 88 81 88 88
88 88 81 Content (weight-%)
TEST EXAMPLE 3
[0238] The properties of the prepared encapsulating epoxy resin
molding materials III-1 to III-13 were determined in the following
tests. The results are shown in Table 14.
[0239] (1) Spiral Flow
[0240] The encapsulating epoxy resin molding material was molded
with a spiral flow-measuring mold according to EMMI-1-66 by a
transfer molding machine at a mold temperature of 180.degree. C.,
at a molding pressure of 6.9 MPa for a curing time of 90 seconds,
and then the distance of flow (cm) was determined.
[0241] (2) Disk Flow
[0242] Using a disk flow-measuring flat mold having an upper mold
of 200 mm (W).times.200 mm (D).times.25 mm (H) and a lower mold of
200 mm (W).times.200 mm (D).times.15 mm (H), the weighed sample
(encapsulating epoxy resin molding material)5 g, was placed on the
center of the lower mold heated at 180.degree. C.; and 5 seconds
later, the upper mold heated at 180.degree. C. was closed; and the
sample was compression-molded under a loading of 78 N for a curing
time of 90 seconds; and the major axis (mm) and the minor axis (mm)
of the molded product were measured with calipers, and their
average value (mm) was determined as disk flow.
[0243] (3) Hardness Upon Heating
[0244] The encapsulating epoxy resin molding material was molded
into a disk of 50 mm diameter.times.3 mm thickness under the
above-described conditions, and immediately after molding, the disk
was measured with a Shore D type hardness meter.
[0245] (4) Flame Retardancy
[0246] The encapsulating epoxy resin molding material was molded
under the above-described conditions with a mold for molding a test
specimen having a thickness of {fraction (1/16)} inch, then cured
at 180.degree. C. for 5 hours and evaluated for flame retardancy
according to an UL-94 test method.
10TABLE 10 Molding Material No. III 1 2 3 4 5 6 7 8 9 10 11 12 13
Examples III Comparative Examples III Characteristics 1 2 3 4 5 6 7
8 9 1 2 3 4 Spiral flow (cm) 117 110 120 102 119 123 115 113 105 93
87 89 85 Disk flow (mm) 92 85 90 83 95 98 89 88 82 75 68 73 70
Hardness upon 70 78 65 80 69 68 72 74 75 75 78 80 85 heating (Shore
D) UL-94 test V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-0 V-1 V-0 V-0
V-0
EXAMPLES III-10 to III-27 COMPARATIVE EXAMPLES III-5 to III-12
[0247] (B-III) Preparation of Semiconductor Devices Preparation of
Semiconductor Devices (LQFP and QFP)
[0248] Using the encapsulating epoxy resin molding materials III-1
to III-9 (Examples III-10 to III-27) or the molding materials
III-10 to III-13 (Comparative Examples III-5 to III-12),
semiconductor devices were prepared in the following manner.
Encapsulation in the encapsulating epoxy resin molding material was
carried out by molding at a mold temperature of 180.degree. C., at
a molding pressure of 6.9 MPa for a curing time of 90 seconds in a
transfer molding machine, followed by post-curing at 180.degree. C.
for 5 hours.
[0249] Using the encapsulating epoxy resin molding materials III-1
to III-9 (Examples III-10 to III-18) or the molding materials
III-10 to III-13 (Comparative Examples III-5 to III-8),
semiconductor devices (100-pin LQFP) having an external size of 20
mm.times.20 mm and a total thickness of 1.5 mm were prepared.
[0250] Said semiconductor devices were mounted with a test silicone
chip of 10 mm.times.10 mm.times.0.4 mm (area 100 mm.sup.2) with a
pad pitch of 80 .mu.m, subjected to wire bonding with a wire of 18
.mu.m in diameter and 3 mm in maximum length and having the
encapsulating material of 0.5 mm in thickness on the upper surface
of the semiconductor chip and the encapsulating material of 0.5 mm
in thickness on the back of the semiconductor chip.
[0251] Using the encapsulating epoxy resin molding materials III-1
to III-9 (Examples III-19 to III-27) or the molding materials
III-10 to III-13 (Comparative Examples III-9 to III-12), the
semiconductor devices (64-pin QFP-1H) in Comparative Examples III-5
to III-17 having an external size of 20 m.times.x20 mm and a total
thickness of 2.7 mm, mounted with a test silicone chip of 4
mm.times.4 mm.times.0.4 mm (area 16 mm.sup.2) with a pad pitch of
100 .mu.m, subjected to wire bonding with a wire of 18 .mu.m in
diameter and 1.5 mm in maximum length and having the encapsulating
material of 1.1 mm in thickness on the upper surface of the
semiconductor chip and the encapsulating material of 1.1 mm in
thickness on the back of the semiconductor chip, were prepared.
EXAMPLES III-28 to III-45 COMPARATIVE EXAMPLES III-13 to III-20
[0252] Preparation of Semiconductor Devices (OMPAC Type BGA)
[0253] Using the encapsulating epoxy resin molding materials III-1
to III-9 (Examples III-28 to III-45) or the molding materials
III-10 to III-13 (Comparative Examples III-13 to III-20),
semiconductor devices were prepared in the following manner.
Encapsulation in the encapsulating epoxy resin molding material was
carried out by molding at a mold temperature of 180.degree. C., at
a molding pressure of 6.9 MPa for a curing time of 90 seconds in a
transfer molding machine, followed by post-curing at 180.degree. C.
for 5 hours.
[0254] An insulating base substrate (glass cloth-epoxy resin
laminated plate available under the trade name E-679, manufactured
by Hitachi Chemical Co., Ltd.) was provided with a fine wiring
pattern, then coated with an insulating protective resist (trade
name: PSR4000AUS5, manufactured by TAIYO INK MFG. CO. LTD.) on the
surface thereof, except for metal-plated terminals at a
semiconductor chip-mounting side and external connecting terminals
at its opposite side. The resulting semiconductor element-mounting
substrate having an external dimension of length 26.2
mm.times.width 26.2 mm.times.thickness 0.6 mm was dried at
120.degree. C. for 2 hours, then coated with an adhesive (trade
name: EN-X50, manufactured by Hitachi Chemical Co., Ltd.), mounted
with a semiconductor element having a size of length 9
mm.times.width 9 mm.times.thickness 0.51 mm (area 81 mm.sup.2) and
a pad pitch of 80 .mu.m. The semiconductor element-mounting
substrate was heated at a predetermined rate of increasing
temperature from room temperature to 180.degree. C. in 1 hour in a
clean oven, further heated at a constant temperature of 180.degree.
C. for 1 hour. Thereafter, the wire bonding region and the
semiconductor element were wire-bonded with a metal wire of 30
.mu.m in diameter and 5 mm in maximum length. Then, the
encapsulating epoxy resin molding materials 1 to 9 were
transfer-molded to a dimension of length 26.2 mm.times.width 26.2
mm.times.thickness 0.9 mm on the semiconductor element-mounted
surface (BGA device of 1.5 mm in thickness) under the conditions
described above, whereby the BGA devices in Examples III-28 to
III-36 were prepared.
[0255] Using the molding materials III-10 to III-13 in place of the
molding materials III-1 to III-9, the semiconductor devices in
Comparative Examples III-13 to III-16 were prepared in the same
manner as in Examples III-28 to III-36.
[0256] Further, a substrate mounted with a semiconductor element of
length 4 mm.times.width 4 mm.times.thickness 0.51 mm (area 16
mm.sup.2) with a pad pitch of 100 .mu.m, wherein the wire bonding
region and the semiconductor element were wire-bonded with a metal
wire of 30 .mu.m in diameter and 1.5 mm in maximum length, was
prepared in the same manner as in Examples III-28 to III-36. And
then the encapsulating epoxy resin molding materials III-1 to III-9
or III-10 to III-13 were transfer-molded to a dimension of length
26.2 mm.times.width 26.2 mm.times.thickness 1.9 mm on the
semiconductor element-mounted surface (BGA device of 2.5 mm in
thickness) under the above-described conditions, whereby the BGA
devices in Examples III-37 to III-45 or Comparative Examples III-17
to III-20 were prepared. (Examples III-46 to III-63) (Comparative
Examples III-21 to III-28)
[0257] Preparation of Semiconductor Devices (Mold Array Package
Type Stacked BGA)
[0258] Using the encapsulating epoxy resin molding materials III-1
to III-9 (Examples III-46 to III-63) or the molding materials
III-10 to III-13 (Comparative Examples III-21 to III-28),
semiconductor devices were prepared in the following manner.
Encapsulation in the encapsulating epoxy resin molding material was
carried out by molding at a mold temperature of 180.degree. C., at
a molding pressure of 6.9 MPa for a curing time of 90 seconds in a
transfer molding machine, followed by post-curing at 180.degree. C.
for 5 hours.
[0259] As shown in FIG. 5, 56 laminated semiconductor elements,
each laminate consisting of two semiconductor elements of 9.7
mm.times.6.0 mm.times.0.4 mm (area 58 mm.sup.2) with a pad pitch of
80 .mu.m and coated on the back thereof with a die bond film DF-400
manufactured by Hitachi Kagaku Kogyo Co., Ltd., were arranged on a
polyimide substrate of length 48 mm.times.width 171
mm.times.thickness 0.15 mm, and then contact-bonded at a
contact-bonding pressure of 200.degree. C. under a loading of 200
gf for a contact-bonding time of 10 seconds and further baked at
180.degree. C. for 1 hour. Thereafter, the wire bonding region and
the semiconductor element were wire-bonded with a metal wire of 30
.mu.m in diameter and 5 mm in maximum length. Then, the
encapsulating epoxy resin molding materials 1 to 9 were
transfer-molded to a dimension of length 40 mm.times.width 83
mm.times.thickness 0.8 mm on the surface mounted with the
semiconductor elements (BGA device of 0.95 mm in thickness) under
the conditions described above as shown in FIG. 5, to prepare the
BGA devices in Examples III-46 to III-54.
[0260] Using the molding materials III-10 to III-13 in place of the
molding materials III-1 to III-9, the semiconductor devices in
Comparative Examples III-21 to III-24 were prepared in the same
manner as in Examples III-46 to III-54.
[0261] Further, a substrate mounted with only one semiconductor
element of 5.1 mm.times.3.1 mm.times.0.4 mm 8area 16 mm.sup.2) with
a pad pitch of 100 .mu.m, wherein the wire bonding region and the
semiconductor element were wire-bonded with a wire of 30 .mu.m in
diameter and 1.5 mm in maximum length, was prepared in the same
manner as in Examples III-46 to III-54, and the encapsulating epoxy
resin molding materials III-1 to III-13 were transfer-molded to a
dimension of length 40 mm.times.width 83 mm.times.thickness 2.5 mm
on the surface mounted with the semiconductor element (BGA device
of 2.65 mm in thickness) under the conditions described above to
prepare the BGA devices in Examples III-55 to III-63 or Comparative
Examples III-25 to III-28.
[0262] The prepared semiconductor devices in Examples III-10 to
III-63 and Comparative Examples III-5 to III-28 were evaluated for
(1) wire sweep (indicator of wire sweep) and (2) the number of
generated voids by the test method 2 described above. The
evaluation results are shown in Tables 11 to 16.
11TABLE 11 Molding Material 1 2 3 4 5 6 7 8 9 10 11 12 13 III No.
Characteristics Examples III Comparative Examples III 10 11 12 13
14 15 16 17 18 5 6 7 8 Wire sweep (%) 3 5 5 7 2 2 3 5 8 12 15 14 18
Number of 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 2/20 4/20
4/20 5/20 generated voids
[0263]
12TABLE 12 Molding Material 1 2 3 4 5 6 7 8 9 10 11 12 13 III No.
Characteristics Examples III Comparative Examples III 19 20 21 22
23 24 25 26 27 9 10 11 12 Wire sweep (%) 0 0 0 0 0 0 0 0 0 3 5 4 7
Number of 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 2/20
0/20 0/20 generated voids
[0264]
13TABLE 13 Molding Material 1 2 3 4 5 6 7 8 9 10 11 12 13 III No.
Characteristics Examples III Comparative Examples III 28 29 30 31
32 33 34 35 36 13 14 15 16 Wire sweep (%) 5 7 7 8 3 3 4 6 8 16 20
18 22 Number of 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 5/20
8/20 8/20 10/20 generated voids
[0265]
14TABLE 14 Molding Material 1 2 3 4 5 6 7 8 9 10 11 12 13 III No.
Characteristics Examples III Comparative Examples III 37 38 39 40
41 42 43 44 45 17 18 19 20 Wire sweep (%) 2 3 3 3 0 1 2 3 3 7 8 7 9
Number of 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 3/20
1/20 2/20 generated voids
[0266]
15TABLE 15 Molding Material 1 2 3 4 5 6 7 8 9 10 11 12 13 III No.
Characteristics Examples III Comparative Examples III 46 47 48 49
50 51 52 53 54 21 22 23 24 Wire sweep (%) 7 8 8 9 6 6 7 7 9 18 24
22 25 Number of 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 8/20
10/20 9/20 10/20 generated voids
[0267]
16TABLE 16 Molding Material 1 2 3 4 5 6 7 8 9 10 11 12 13 III No.
Characteristics Examples III Comparative Examples III 55 56 57 58
59 60 61 62 63 25 26 27 28 Wire sweep (%) 3 3 3 3 2 2 2 3 3 9 10 9
11 Number of 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 0/20 2/20
2/20 2/20 generated voids
[0268] As can be seen from the results in Tables 11 to 16, the
semiconductor devices in Comparative Examples III-5 to III-28,
encapsulated in the encapsulating epoxy resin molding materials
III-10 to III-13 containing neither the silane coupling agent
having a secondary amino group (C) nor the phosphate (D), generate
the molding defect of either wire sweep (high wire deformation) or
generation of voids.
[0269] On the other hand, it is evident form the results in Tables
15 to 20 that the encapsulating epoxy resin molding materials III-1
and III-9 containing the epoxy resin (A), the curing agent (B), the
inorganic filler (E), the curing accelerator (F) and the phosphate
(D), are excellent in fluidity, and the semiconductor devices in
Examples III-10 to III-63, encapsulated therein, are excellent in
moldability without generating voids with no wire sweep or with
minimum wire deformation.
[0270] Those skilled in the art can understand that besides the
embodiments described above, many modifications and alterations can
be practiced without departure from the sprit and scope of this
invention.
[0271] Industrial Applicability
[0272] The encapsulating epoxy resin molding material for thin
semiconductor devices according to this invention is excellent in
fluidity, and the semiconductor device encapsulated therein, which
is a semiconductor device having a semiconductor chip arranged on a
thin, multi-pin, long wire, narrow-pad-pitch, or on a mounted
substrate such as organic substrate or organic film, is free of
molding defects such as wire sweep, voids etc. as shown in the
Examples, and thus its industrial value is significant.
* * * * *