JPH0639517B2 - Epoxy resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a liquid epoxy resin encapsulating material used for encapsulating a semiconductor element or an electronic component 2.

[Conventional technology]

Mounting a semiconductor element or electronic component on an organic printed wiring board or ceramic wiring board, and physically or chemically protecting them, and drip, potting or coating the liquid resin composition to fix or fix them. Is being done. In recent years, due to the higher functionality and higher integration of semiconductor elements, one chip has become larger and has become a resin-encapsulated molded product.In semiconductor devices, the difference in dimensional change between the chip and the resin-encapsulated molded product has become noticeable, causing cracks. It's getting easier.
Further, there is a demand for performance that does not cause cracks in a semiconductor device even under severer usage conditions.
Under such circumstances, there is a strong demand for reduction of the linear expansion coefficient of the liquid resin composition. The conventional linear expansion coefficient (α ₁ ) of 2.1 × 10 ⁻⁵ or more is 2.0 × 10 ⁻⁵ or less,
In order to obtain a low linear expansion coefficient, one method is to increase the proportion of the inorganic filler in the liquid epoxy resin composition to 60 to 80% by weight. However, in a solvent-free, one-liquid epoxy resin composition, the proportion of the inorganic filler in the liquid epoxy resin composition is at most 60% by weight, and if it is further blended, the viscosity of the liquid epoxy resin composition will be high. It becomes impossible to use. There is a way to use a solvent for this,
Since the obtained epoxy resin composition disappears without a solvent, there is a problem that the change in viscosity with time becomes large, and traces of solvent escaped in the form of pinholes on the surface of the cured product.

[Problems to be Solved by the Invention]

In view of the above circumstances, the present invention provides an epoxy resin composition that is solvent-free, one-component, has a low viscosity, a low linear expansion coefficient, and excellent heat cycle properties.

[Means for Solving the Problems]

The present inventors arrived at the present invention while researching the constitution of various epoxy resins and fillers. That is, the epoxy resin composition of the present invention comprises: (a) as an epoxy resin, bisphenol A type epoxy resin (A) bisphenol F type epoxy resin (F) trifunctional or higher liquid epoxy resin (P) Epoxy resin and F / each blended in the amounts shown in the following two formulas.
(A + F + P) ≦ 4/9 Formula 1 P / (A + F + P) ≦ 2/9 Formula 2 (b) 60 to 80% by weight of the epoxy resin composition, of which 30% by weight or more is spherical. It is characterized by comprising a filler (c) and an acid anhydride curing agent.

These inventions will be described in detail below.

As the epoxy resin according to the present invention, a commonly used bisphenol A type epoxy resin (A), a commonly used bisphenol F type epoxy resin (F), a commonly used trifunctional or higher functional liquid epoxy resin (P), and these are difficult. It is possible to use a combination of halogenated epoxy resins having flame resistance and the like, and each has the following effects. That is, the bisphenol F type epoxy resin (F) lowers the viscosity and the glass transition point (Tg),
The trifunctional or higher functional liquid epoxy resin (P) increases the viscosity and Tg. Therefore, in order to achieve a low linear expansion coefficient, in order to reduce the viscosity of the epoxy resin composition in which the inorganic filler is highly filled up to 60 to 80% by weight in the liquid epoxy resin composition, the bisphenol F type epoxy resin is used. It is sufficient to use a large amount of (F), but at the same time, Tg gradually decreases, and it becomes impossible to secure a low linear expansion coefficient at high temperatures. Therefore, the bisphenol F type epoxy resin (F) can be used in the range of Formula 1. Limited. That is, when the condition of Expression 1 is not satisfied, Tg is lowered, the linear expansion coefficient is increased, and the heat cycle property is also lowered, which is not preferable.

F / (A + F + P) ≦ 4/9 Formula 1 On the other hand, the use of a trifunctional or higher functional liquid epoxy resin (P) is effective for securing a high Tg, but at the same time the viscosity also increases, so a trifunctional or higher functional liquid epoxy is used. The resin is limited to use in the range of equation 2. That is, when the condition of the formula 2 is not satisfied, it becomes difficult to prepare a resin composition due to an increase in viscosity, and the moldability of the obtained resin composition is remarkably deteriorated so that it cannot be put to practical use.

P / (A + F + P) ≦ 2/9 ... Formula 2 The resin composition to be obtained in the present invention is, of course, a moldability for obtaining a good molded product on the assumption that the characteristic product performance of the molded product is sufficiently brought out. In order to exhibit both of these characteristics, it is necessary that the compounding ratio be such that both of the above formulas 1 and 2 are satisfied.

As the filler, inorganic fillers such as silica, alumina, silicon nitride, talc, calcium carbonate, magnesium carbonate and aluminum hydroxide can be used. Of these, high-purity silica is particularly preferable because it is a suitable list and can obtain characteristics of a low linear expansion coefficient. In order to lower the linear expansion coefficient of the epoxy resin composition, it is preferable to mix such an inorganic filler as much as possible, but 60 to 80% by weight of the epoxy resin composition is suitable from the viewpoint of ensuring uniform mixing and ease of use. By using a filler in which 30% by weight or more of the filling amount is spherical, the viscosity of the one-component resin composition can be further reduced. When an inorganic filler having an average particle size of 15 μm or less is used, the inorganic filler can be prevented from settling in the liquid resin composition.

As the acid anhydride as a curing agent, a compound having one acid anhydride group in one molecule is methylhexahydrophthalic anhydride (MHHPA, shown in the following structural formula 1), and 2 or more in one molecule. In the compound having an acid anhydride group, 5- (2,
5-Dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride (MCDCA, shown in Structural Formula 2 below) and the like are used.

A liquid acid anhydride such as MHHPA is preferable because it can be easily compatible with the liquid epoxy resin. The acid anhydride curing agent may be used in an amount of 50 to 100 parts by weight based on 100 parts by weight of the total amount of the three epoxy resins. This range is preferable,
If it is used in an amount of less than 50 parts by weight, it cannot be sufficiently cured and the water absorption rate of the obtained molded article becomes large. If it is used in an amount of more than 100 parts by weight, the curing proceeds rapidly and the workability is poor.
This is because the pot life of the resin composition is shortened.

In addition, it is preferable to use a latent curing accelerator in order to prolong the pot life of the epoxy resin composition and to complete the curing early, for example, 2,4-diamine-6.
Examples thereof include {2′-methylimidazolyl- (1) ′} ethyl-s-triazine / isocyanuric acid adduct (2MA-OK, shown in the following structural formula 3).

Furthermore, various additives are used if necessary.
For example, a coupling agent, a surfactant, a leveling agent, an antifoaming agent, an ion trap agent, a flame retardant, a coloring agent, a diluent, a lubricant, etc.

The liquid epoxy resin composition according to the present invention can be obtained, for example, by mixing the above-mentioned components and then kneading them with a roll, a disper, an ajihomo mixer, a planetary mixer, a kneader, a raider or the like. At this time, when the viscosity is too high, it may be heated up to about 50 ° C.
In addition, it is preferable to deaerate bubbles contained in the resin composition during and after the kneading under reduced pressure.

[Examples] Examples 1 to 7 Bisphenol A glycidyl ether (epoxy equivalent 175, viscosity 4500 cps) as bisphenol A type epoxy resin (A), bisphenol F glycidyl ether (epoxy equivalent 170, viscosity) as bisphenol F type epoxy resin (F) 1500 cps), and as a trifunctional or higher functional liquid epoxy resin (P), a phenol novolac type epoxy resin (n = 1 to 3 in the following structural formula,
The total weight parts of these three epoxy resins having an average molecular weight of 810 and an epoxy equivalent of 180) were 9 and the compounding ratio was changed.

Three types of silica were used as the filler. (a) Silica consisting of 80% by weight of spherical silica having an average particle size of 15 μm and 20% by weight of crushed silica, and (b) an average particle size of 15 μm.
Of 60% by weight of spherical silica and 40% by weight of crushed silica, (c) silica of 100% by weight of crushed silica, in a resin composition of silica using these alone or in combination. The content rate of was changed. Example 1
Table 1 shows the compounding ratios of the above-mentioned three epoxy resins and the compounding amounts of the fillers, which are changed every 7 to 7.

As a curing agent, MHHPA and MCDCA were used in a ratio of 7 and 3 in an amount of 75 parts by weight per 100 parts by weight of the above three epoxy resins in common in Examples 1 to 7 and Comparative Examples 1 to 4.

As the curing accelerator, 2 parts of MA-OK was also used in common in Examples 1 to 7 and Comparative Examples 1 to 4 with respect to the total amount of the epoxy resin and the acid anhydride resin.

Comparative Example 1 Example 1 was repeated except that the amount of the filler in Example 1 was changed to 55 parts by weight.

Comparative Example 2 The procedure of Example 1 was repeated except that the type of the filler in Example 1 was changed to 100% crushed silica and the use of spherical silica was set to 0.

Comparative Example 3 Example 1 was repeated except that the compounding ratio of the three epoxy resins in Example 1 was changed and the compounding amount of the bisphenol F type epoxy resin (F) was changed to 5/9.

Comparative Example 4 Liquid 3 was changed by changing the compounding ratio of the three epoxy resins of Example 1.
The same procedure as in Example 1 was carried out except that the compounding amount of the functional epoxy resin (P) was changed to 3/9.

The viscosities of the epoxy resin compositions of Examples 1 to 7 and Comparative Examples 1 to 4 were measured with a B-type viscometer to determine the linear expansion coefficient (α ₁ ) and Tg.
Was evaluated with a delight meter. The heat cycle property is as follows: 1 gold wire with a diameter of 25 μm on an alumina ceramic substrate
Four wire-bonded 2.3 × 3.2 mm square silicon IC chips were drip-coated with the above epoxy resin composition and then cured at 150 ° C. for 3 hours to obtain 10 pieces each.
Samples were prepared and left at -65 [deg.] C. and 150 [deg.] C. for 30 minutes each as one cycle. Up to 1000 cycles were performed, and the presence or absence of cracks was visually inspected and evaluated every predetermined number of times of processing. The results of these evaluations are shown in Table 2.

From Table 2, it is confirmed that the epoxy resin compositions of Examples 1 to 7 have lower viscosity, lower linear expansion coefficient, higher Tg, and better heat cycle property than those of Comparative Examples 1 to 4. did it.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY The epoxy resin composition of the present invention is solvent-free, one-component and has a low viscosity, and has excellent characteristics of low linear expansion coefficient and heat cycle property.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical indication location H01L 23/31 (56) References JP 62-57417 (JP, A) JP 63- 159426 (JP, A) JP 61-250022 (JP, A) JP 56-53130 (JP, A)

Claims (1)

[Claims] (A) As an epoxy resin, a bisphenol A type epoxy resin (A), a bisphenol F type epoxy resin (F), a trifunctional or higher functional liquid epoxy resin (P), and the above epoxy resins in the following two parts by weight. Epoxy resin, F /
(A + F + P) ≦ 4/9 Formula 1 P / (A + F + P) ≦ 2/9 Formula 2 (b) 60 to 80% by weight of the epoxy resin composition, of which 30% by weight or more is spherical. Epoxy resin composition comprising a filler, (c) and an acid anhydride curing agent