JPH08134330A - Epoxy resin composition for sealing tab and tab device - Google Patents

Abstract

PURPOSE: To obtain an epoxy resin composition for tape automated bonding(TAB) sealing, excellent in low stress properties and capable of providing a cured product excellent in filling properties in a narrow gap and suitable as a transfer moldable resin for the TAB sealing. CONSTITUTION: This epoxy resin composition for TAB sealing is obtained by using a resin component having <=14cSt viscosity at 25 deg.C of a 40wt.% solution in methyl isobutyl ketone as the resin component comprising an epoxy resin and a curing agent and blending fused silica having a particle size distribution of <=0.2wt.% particles having >=24μm particle diameter, 20-80wt.% particles having >=3μm particle diameter and 20-80wt.% particles having <3μm, and an average particle diameter of <=10μm as an inorganic filler in an amount of 65-90wt.% based on the whole composition therewith in the epoxy resin composition for the TAB sealing containing the epoxy resin, curing agent and inorganic filler.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a transfer moldable TAB encapsulating epoxy resin composition which is excellent in low stress property and has an improved filling property in a narrow gap of 30 to 60 μm, and a curing of the composition. TA sealed with objects
B device.

[0002]

2. Description of the Related Art
In the semiconductor industry, resin-sealed diodes, transistors, ICs, LSIs, and VLSIs have become the mainstream. Epoxy resin is generally used as the sealing resin as compared with other thermosetting resins in terms of moldability, adhesiveness, electrical characteristics, mechanical characteristics,
Due to its excellent moisture resistance and the like, a semiconductor device is often sealed with an epoxy resin composition.

Recently, the degree of integration of these semiconductor devices has been increasing, and the chip size has been increasing accordingly. On the other hand, the outer dimensions of the package are becoming thinner in accordance with the demand for smaller and lighter electronic devices, and the TAB (Tape Automated Bonding) package is a very simple one. However, when this TAB is transfer-molded, the conventional sealing material causes a problem of stress, and for example, 30-60.
There is a problem that unfilling occurs due to poor filling property in a narrow gap of about μm.

The present invention has been made in view of the above circumstances.
A transfer moldable TAB encapsulating epoxy resin composition which is excellent in low stress properties and improved in filling in narrow gaps, and a TA encapsulated with a cured product of this composition
It is intended to provide a B device.

[0005]

Means and Actions for Solving the Problems As a result of intensive studies for achieving the above object, the present inventor has found that an epoxy resin for TAB encapsulation containing an epoxy resin, a curing agent and an inorganic filler. In the composition, as a resin component composed of an epoxy resin and a curing agent, a 40 wt% methyl isobutyl ketone solution having a viscosity at 25 ° C. of 14 centistokes or less is used, and as an inorganic filler, a particle diameter is 24 μm. 0.2% by weight or less of the above particles,
20 to 80% by weight of particles of 3 μm or more has a particle size distribution of 20 to 80% by weight of particles of less than 3 μm, and fused silica having an average particle size of 10 μm or less is 65 to 90% of the entire composition.
By blending by weight, the composition has low stress, low viscosity in a high temperature molten state, and excellent flowability. Moreover, since it does not contain coarse silica particles, it can be filled in a narrow gap of about 30 to 60 μm. A resin composition for TAB encapsulation which is extremely good and is transfer moldable is obtained,
The TAB device sealed with this composition was found to be highly reliable, and the present invention was completed.

Therefore, the present invention provides an epoxy resin composition for TAB encapsulation containing an epoxy resin, a curing agent and an inorganic filler, wherein the resin component comprising the epoxy resin and the curing agent is 40% by weight methyl. Use an isobutyl ketone solution having a viscosity of 14 centistokes or less at 25 ° C., and use an inorganic filler having a particle size of 2
0.2 wt% or less of particles of 4 μm or more, 20 to 80 wt% of particles of 3 μm or more, 20 to 80 of particles of less than 3 μm
Epoxy resin composition for TAB encapsulation, characterized in that it contains 65 to 90% by weight of fused silica having a particle size distribution of 10% by weight and an average particle size of 10 μm or less, and the above epoxy. Provided is a TAB device sealed with a cured product of a resin composition.

The present invention will be described in more detail below. The TAB encapsulating epoxy resin composition of the present invention contains the epoxy resin, the curing agent and the inorganic filler as the main components as described above.

Here, the epoxy resin used in the present invention may be any epoxy resin as long as it has at least two epoxy groups in one molecule, specifically, bisphenol A type epoxy resin and phenol. Novolac type epoxy resin, triphenol alkane type epoxy resin and its polymer, biphenyl type epoxy resin, dicyclopentadiene-phenol novolac resin, phenol aralkyl type epoxy resin, naphthalene ring-containing epoxy resin, glycidyl ester type epoxy resin, alicyclic Epoxy resin, heterocyclic epoxy resin, brominated epoxy resin and the like can be used. Among these epoxy resins, the triphenolalkane-type epoxy resin and the biphenyl-type epoxy resin have relatively low melt viscosities, and are therefore desirable from the viewpoint of obtaining high filling properties. It should be noted that these epoxy resins are not necessarily limited to one type of use in use, and may be a mixture of two or more types.

The curing agent is not particularly limited and can be appropriately selected according to the epoxy resin used, and examples thereof include amine type curing agents, acid anhydride type curing agents and phenol novolac type curing agents. Among them, among them, a phenol novolak type curing agent is more preferable in terms of moldability and moisture resistance of the composition, and can be preferably used, as the phenol novolac type curing agent, specifically, phenol novolac resin, cresol novolac resin , Phenol aralkyl novolac resin and the like.

The compounding amount of the above-mentioned curing agent can be an amount usually used within a range capable of curing an epoxy resin,
When a phenol novolac type curing agent is used, it is preferable to mix it so that the molar ratio of the epoxy groups in the epoxy resin to the OH groups in the curing agent is 1: 0.5 to 1: 1.5. .

In this case, in the present invention, in order to improve the filling property into the TAB, as a resin component comprising the above epoxy resin and a curing agent, the viscosity thereof is 40 wt% in methyl isobutyl ketone solution at 25 ° C. and 14 cs or less, It is necessary to select a resin component that is preferably 12 cs or less. When the viscosity of the resin component exceeds 14 cs, as will be described later, the melt viscosity of the obtained composition becomes high even if 65% by weight or more of fused silica is used in order to reduce the linear expansion coefficient and reduce the stress. As a result, the filling property into the TAB becomes poor.

In the present invention, it is desirable to add various curing accelerators such as imidazoles, tertiary amines, phosphine compounds, cycloamidine compounds and the like for the purpose of accelerating the reaction between the epoxy resin and the curing agent. . The blending amount is not particularly limited, but is usually 0.
It is preferably set to 05 to 1% by weight.

Further, in the present invention, it is preferable to add a silicone polymer to the composition for the purpose of reducing the stress of the cured product. When a silicone-based polymer is blended, it is possible to significantly reduce the occurrence of package cracks in the thermal shock test of the cured product. Examples of the silicone-based polymer include a silicone oil having an epoxy group, an amino group, a carboxyl group, a hydroxyl group, a hydrosilyl group, a vinyl group, a silicone resin, and the like.
Examples thereof include silicone rubber and the like, and copolymers of these silicone polymers and organic polymers such as substituted or unsubstituted phenol novolac resins.

The addition amount of the silicone-based polymer is not particularly limited, but it is usually preferably 1 to 50 parts per 100 parts (part by weight, the same applies hereinafter) of the total amount of the epoxy resin and the curing agent.

Further, for the purpose of imparting flexibility and toughness to the cured product, various organic synthetic rubbers, thermoplastic resins such as methyl methacrylate-styrene-butadiene copolymer, styrene-ethylene-butene-styrene copolymer and the like. Can be added. In this case, the above-mentioned methyl methacrylate-styrene-butadiene copolymer can exert the effect of reducing the stress of the cured product of the epoxy resin composition.

In the present invention, the particle size of the inorganic filler is 24
0.2% by weight or less of particles of μm or more, preferably 0 to
0.1% by weight, 20 to 80% by weight of particles of 3 μm or more,
Preferably 30-70% by weight and less than 3 μm particles are 20
-80% by weight, preferably 30-70% by weight, with an average particle size of 10 μm or less, preferably 2-8 μm.
m fused silica. 0.2 is more than 24μm
If the content is more than wt%, the coarse particles will block the gaps in the TAB, resulting in poor filling properties. Further, when a filler having a particle size distribution in which 3 μm or more exceeds 80% by weight or less than 20% by weight is used, the viscosity of the obtained composition becomes too high and the filling property is deteriorated. There is a disadvantage. Even when a filler having an average particle size of more than 10 μm is used, the filling property is deteriorated.

The above-mentioned inorganic filler needs to be fused silica in view of the coefficient of linear expansion, purity, and price, but crystalline silica, alumina, silicon nitride, aluminum nitride are acceptable as long as the object of the present invention is not impaired. It is possible to use the above together.

In order to achieve both low expansion of the cured product and moldability, it is recommended to use a blend of spherical products and crushed products, or to use only spherical products. In particular, it is desirable to use silica which has a controlled particle size distribution and gives high fluidity when blended in the composition.

The above fused silica is preferably treated with a silane coupling agent in advance. Here, as the silane coupling agent, a conventionally known one can be used, and 3-glycidoxypropyltrimethoxysilane, 3
-Aminopropyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane and the like are exemplified.

The amount of the silane coupling agent used is preferably 0.1 to 1 part, more preferably 0.2 to 0.6 part, based on the fused silica. If the amount is less than 0.1 part, the interface between the resin and the inorganic filler may not be sufficiently controlled when applied to a resin composition comprising the resin and the inorganic filler, and if the amount exceeds 1 part, an aggregate of the inorganic filler is obtained. May not be possible.

The blending amount of the above-mentioned fused silica is 65 to 90% by weight, preferably 70 to 85% by weight, based on the whole composition. If the filling amount is less than 65% by weight, the expansion coefficient of the obtained cured product will be large, resulting in poor stress characteristics. If the filling amount is more than 90% by weight, the melt viscosity at the time of molding will be too high. Occurs.

If desired, various additives may be further added to the composition of the present invention. For example, waxes such as carnauba wax, release agents such as fatty acids such as stearic acid and metal salts thereof (including adhesiveness). , Carnauba wax is preferably used from the viewpoint of releasing property), carbon black, cobalt blue, pigments such as red iron oxide, antimony oxide, flame retardants such as halogen compounds, γ-glycidoxypropyltrimethoxysilane, etc. One or more of surface treatment agents, silane coupling agents such as epoxysilanes, boron compounds, alkyl titanates, antiaging agents, and other additives can be blended.

In the production of the epoxy resin composition of the present invention, a predetermined amount of the above-mentioned components are uniformly stirred and mixed, and the mixture is heated in advance at 70 to 95 ° C. with a kneader, roll, extruder or the like. It can be obtained by a method such as kneading, cooling and pulverizing, and a melt mixing method using a mixing roll and an extruder is particularly preferably used. here,
There is no particular limitation on the order of mixing the components.

The epoxy resin composition of the present invention thus obtained is effective for TAB transfer molding. The molding temperature of the epoxy resin composition of the present invention is 1
It is preferable to carry out at 50 to 180 ° C. and post cure at 150 to 185 ° C. for 2 to 16 hours.

[0025]

EFFECT OF THE INVENTION The epoxy resin composition for TAB encapsulation of the present invention is excellent in low stress property, improved in filling property in a narrow gap of 30 to 60 μm, and is transfer moldable. The TAB device sealed with the stopping epoxy resin composition is of high quality and high reliability.

[0026]

EXAMPLES The present invention will be specifically described below by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following examples, all parts are parts by weight and% are% by weight.

Examples 1 to 7, Comparative Examples 1 to 7 7 parts of a brominated epoxidized phenol novolac resin having an epoxy equivalent of 280, 60 parts of a compound represented by the following formula (a) and the following formula (b): 10 parts of reaction product with 40 parts of compound,
0.65 parts of triphenylphosphine, 10 parts of antimony trioxide, 1.2 parts of carnauba wax, 1.0 part of γ-glycidoxypropyltrimethoxysilane, 1 part of carbon black, fused silica shown in Table 1, epoxy equivalent 166 ,
Epoxidized triphenol methane resin having a softening point of 54 ° C. (epoxy resin A), epoxy equivalent 190, softening point 10
4,4'-glycidyloxy-2,6,2 'at 6 ° C
6'-tetramethylbiphenyl resin (epoxy resin B), epoxy equivalent 198, epoxidized cresol novolac resin having a softening point of 80 ° C (epoxy resin C), phenol equivalent 110, phenol novolac resin having a softening point of 90 ° C (phenol resin A) Were mixed in the compositions and amounts shown in Tables 2 and 3, melt-mixed for 5 minutes with a mixing roll at 80 ° C., taken out as a sheet, and cooled and pulverized to obtain an epoxy resin composition.

[0028]

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The following tests (a) to (d) were conducted on the obtained epoxy resin composition. The results are shown in Table 2.
3 shows. (A) Melt viscosity 175 ° C using a Shimadzu high-performance flow tester,
The viscosity under a load of 10 kg was measured. (B) Spiral flow 175 ° C, 70k using a mold conforming to EMMI standard
It was measured under the condition of gf / cm ² . (C) TAB filling property A TAB device having a tape of 48 mm width mounted with a 15 mm square silicon chip and a minimum filling gap of 40 μm was used at 175 ° C. for 2 hours at 175 ° C. using a transfer mold tester.
The filling property into the minimum gap at the time of minute molding was examined using an ultrasonic flaw detector. OK: Fully filled NG: Unfilled (d) Thermal shock resistance After further curing the TAB apparatus molded in the above (c) at 180 ° C. for 4 hours, 1 in liquid nitrogen Then, the number of cracks generated after 20 cycles and 100 cycles was examined with one cycle of immersion for 30 seconds in a solder bath at 260 ° C. (parameter: 20). NA: Thermal shock test could not be performed due to unfilled

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

From the results shown in Tables 2 and 3, it was confirmed that the epoxy resin composition of the present invention gives a cured product excellent in filling property and low stress.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location H01L 23/31 (72) Inventor Kenichi Totsuka 1 Hitomi, Osamu Matsuida-cho, Usui-gun, Gunma 10 Shin-Etsu Chemical Industry Silicone Electronic Materials Technology Laboratory

Claims (2)

[Claims] 1. A TAB encapsulating epoxy resin composition containing an epoxy resin, a curing agent and an inorganic filler, wherein the resin component comprising the epoxy resin and the curing agent is:
A 40 wt% methyl isobutyl ketone solution having a viscosity at 25 ° C. of 14 centistokes or less is used, and as the inorganic filler, 0.2 wt% or less of particles having a particle diameter of 24 μm or more and 3 μm or more of particles are used. 20 to 80% by weight, particles having a particle size of less than 3 μm are 20 to 80% by weight, and fused silica having an average particle size of 10 μm or less is blended in an amount of 65 to 90% by weight of the entire composition. Epoxy resin composition for TAB sealing. 2. A TAB device sealed with a cured product of the epoxy resin composition according to claim 1.