JPH06841B2 - Epoxy resin molding material for electronic parts encapsulation - Google Patents

Description

The present invention relates to an epoxy resin molding material for sealing electronic parts,
More specifically, the present invention relates to an epoxy resin molding material for electronic component encapsulation, which has excellent thermal shock resistance, heat resistance, and moldability.

[Conventional technology]

BACKGROUND ART Conventionally, epoxy resin molding materials have been widely used for sealing electronic parts such as coils, capacitors, transistors and ICs. The reason for this is that the epoxy resin is well balanced in various characteristics such as electric characteristics, heat resistance, mechanical strength, and adhesiveness with concerts.

However, the package of the electronic component tends to be small and thin as represented by the IC, which causes a problem that the package is cracked during the thermal cycle.

[Problems to be Solved by the Invention]

The present invention has been made to solve the above drawbacks, and is intended to provide an epoxy resin molding material for electronic component encapsulation, which has good thermal shock resistance and heat resistance, and also has excellent moldability. is there.

As a method for improving the thermal shock resistance of the epoxy resin molding material, there is a method of modifying the epoxy resin system with a silicone polymer. Generally, a silicone polymer is incompatible with an epoxy resin system, forms a structure in which fine particles are dispersed in an epoxy resin, and has an effect of improving thermal shock resistance. However, since the silicone polymer is incompatible, the thermal shock resistance of the molding material is improved, but it causes bleeding during molding, burrs (bleeding from the mold clearance) and deterioration of the appearance of the molded product. Therefore, it has been desired to solve this drawback.

[Means for Solving the Problems]

As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by combining a specific compound with an epoxy resin system, and complete the present invention. Came to.

That is, the epoxy resin molding material for electronic parts of the present invention is (A) an epoxy resin having two or more epoxy groups in one molecule, (B) a compound having two or more phenolic hydroxyl groups in one molecule, (C) ) A polyalkylene ether compound and (D) a silicone polymer having an epoxy group and a polyalkylene ether group are essential components.

As the epoxy resin having two or more epoxy groups in one molecule of the component (A) used in the present invention, there is no limitation as long as it is one generally used in epoxy resin molding materials for sealing electronic parts. Epoxidized novolac resins of phenols and aldehydes such as novolac type epoxy resins and orthocresol novolac type epoxy resins, diglycidyl ethers of bisphenol A, bisphenol B, bisphenol F, bisphenol S, phthalic acid dimer acid Glycidyl ester type epoxy resin obtained by reaction of polybasic acid such as epichlorohydrin, glycidyl amine type epoxy resin obtained by reaction of polyamine such as diaminodiphenylmethane, isocyanuric acid and epichlorohydrin, olefin The emissions binding peracetic acid such linear aliphatic epoxy resins obtained by oxidation with peracids, and include alicyclic epoxy resins can be used in combination even these at an appropriate number of types.

Examples of the compound having two or more phenolic hydroxyl groups in one molecule of the component (B) used in the present invention include phenols such as phenol, cresol, xylenol, resorcin, catechol, bisphenol A, bisphenol F, and formaldehyde. There are polyphenols such as novolac type phenol resin, bisphenol A, bisphenol F, polyparavinylphenol resin, resorcin, catechol, and hydroquinone, which are obtained by condensation reaction under an acidic catalyst, and they may be used alone or in combination of two or more. Good. The equivalent ratio to the epoxy resin (A) (the number of hydroxyl groups in (B) / the number of epoxy groups in (A)) is not particularly limited, but is preferably 0.7 to 1.3.

The component (C) used in the present invention is generally [-RO
-] Is a polymer compound composed of repeating units,
Is a methylene group or a polymethylene group and its derivatives. Especially for the thermal shock resistance and moldability (bleeding out at the time of molding), which are the main objects of the present invention, (However, a and b are numbers having a relationship of 0.2 ≦ a / b ≦ 5.) Is preferable, and the molecular weight is 4
00 to 4000 is preferable. The reason for this is that a / b is
This is because when the ratio is 0.2 or less, the compatibility with the epoxy resin as the base resin is poor, and when the ratio is 5 or more, the moisture resistance may decrease due to the hydrophilicity of the ethylene oxide component. Further, when the molecular weight is 400 or less, the effect on the thermal shock resistance and moisture resistance is small or decreases, and when the molecular weight is 4000 or more, compatibility and fluidity during molding may be impaired.

The component (D) used in the present invention has a general formula The structure shown in is fried. Here, R ₁ is a polyalkylene ether group having a structure similar to that of the component (C),
R ₂ is (R ′, R ″ are Alkylene groups such as) and epoxy groups such as. The polyalkylene ether group of R ₁ preferably has a structure satisfying the same condition as the above-mentioned component (C), but does not necessarily have to have the same structure. The ratio of the polyalkylene ether group of R ₁ is preferably 10 to 60% by weight based on the silicone polymer of the component (D), but is not particularly limited. The reason for this is that if it is less than 10% by weight, the compatibility with the base resin is poor and problems such as exudation during molding tend to occur, while if it exceeds 60% by weight, the moisture resistance tends to decrease due to the hydrophilicity of the polyether group. Is.
Further, the ratio of the epoxy group of R ₂ is not particularly limited, but the epoxy equivalent of the silicone polymer of the component (D) is preferably in the range of 1000 to 10000, more preferably 1500 to 3000. .

The reason for this is that the epoxy equivalent is less than 1000 and 100
This is because if it exceeds 00, the effect on the thermal shock resistance is small.

Here, the mixing ratio (weight) of the component (C) and the component (D) is ((C) component + (D) component) / ((A) component +
(B) component) is preferably in the range of 0.02 to 0.2, and (C)
Component + (D) component is preferably in the range of 2 to 0.2, but is not particularly limited. The feature of the present invention resides in that both the component (C) and the component (D) are essential components. By using both of them together, thermal shock resistance is improved, compared with the case of using both separately. No exudation of the molding polymer occurs.

Furthermore, in order to appropriately generate the effects of the present invention,
The component (B), the component (C) and the component (D) can be heated and mixed in advance in the presence of a curing accelerator that accelerates the reaction between the epoxy group and the phenolic hydroxyl group. As this curing accelerator, for example, 1,8-diaza-bicyclo (5,5
4,0) Undecene-7, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tertiary amines such as tris (dimethylaminomethyl) phenol, 2-methylimidazole, 2-phenylimidazole, 2- Imidazoles such as phenyl-4-methylimidazoles and 2-heptadecylimidazole, organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphene and phenylphosphine, tetraphenylphosphonium tetraphenylborate, triphenylphosphine Tetraphe such as phenylphosphine tetraphenylborate, 2-ethyl-4-methylimidazole tetraphenylborate, N-methylmorpholine tetraphenylborate There is such Ruboron salt, suitably 1
One kind or two or more kinds can be used. The above curing accelerators can also be used as curing accelerators for the molding material of the present invention. The conditions for heating and mixing the components (B), (C) and (D) are not particularly limited,
120 ° C. to 180 without solvent or using a suitable solvent
The temperature is preferably in the range of 1 hour to 10 hours. Under this condition, the phenolic hydroxyl group of the component (B) and the epoxy group of the component (D) can effectively react with each other, and the effect of improving heat resistance and impact resistance is large.

The electronic component sealing epoxy resin molding material of the present invention, as an inorganic filler, fused silica, crystalline silica, alumina, zircon, calcium silicate, calcium carbonate,
Powders of silicon carbide, silicon nitride, boron nitride, beryllia, magnesia, zirconia, forsterite, steatite, spinel, mullite, titania, etc., and single crystal fibers of potassium titanate, silicon carbide, silicon nitride, alumina, etc., glass One or more kinds of fibers and the like can be blended. The blending amount of the inorganic filler is not particularly limited, but is preferably 40 to 70% by volume.

Further, the epoxy resin molding material for encapsulating electronic parts of the present invention includes a flame retardant such as antimony trioxide, a higher fatty acid, a higher fatty acid metal salt, a release agent such as ester hooks, a colorant such as carbon black, and an epoxy. Coupling agents such as silanes, aminosilanes, vinylsilanes, alkylsilanes, organic titanates, aluminum alcoholates and the like can be used.

As a general method for producing a molding material using the above raw materials, after thoroughly mixing a predetermined amount of raw material mixture with a mixer or the like, kneading with a hot roll, an extruder or the like, cooling, and pulverizing A molding material can be obtained in this way.

The low-pressure transfer molding method is the most common method for sealing electronic components using the molding material obtained in the present invention, but injection molding, compression molding, casting, and other methods are also possible.

[Action]

The reason why an epoxy resin molding material excellent in heat shock resistance, heat resistance and moldability can be obtained by the present invention is a resin mainly composed of an epoxy resin of (A) and a compound having a phenolic hydroxide machine of (B). It is presumed that this is due to the fact that the polyalkylene ether compound of (C) and the silicone compound having an epoxy group and a polyalkylene ether group of (D) were used as the flexible agent in the system. The silicone compound of the component (D) has a dimethyl siloxane skeleton incompatible with the base resin in the structure and a polyalkylene ether group having a relatively good compatibility. Due to the action of the compatible group, fine particles are incorporated in the base resin. It is believed that the hard and brittle epoxy resin is effectively modified by being dispersed in the resin. Further, it is considered that the polyalkylene ether compound as the component (C) acts effectively in order to keep the dispersion of the component (D) more stable. Therefore, it is essential to use both the component (C) and the component (D) as an essential component as a flexible agent.

〔Example〕

The present invention will be described below with reference to examples, but the scope of the present invention is not limited to these examples.

Example 1 Epoxy equivalent 220, cresol novolac type epoxy resin having a softening point of 78 ° C., 80 parts by weight, epoxy equivalent 37
5, softening point 80 ℃, bromine content 40 wt% brominated bisphenol A type epoxy resin 20 parts by weight, hydroxyl equivalent 10
6, 44 parts by weight of phenol formaldehyde hydro novolac resin having a softening point of 83 ° C., 1.5 parts by weight of triphenylphosphine, 2 parts by weight of carnauba wax, 8 parts by weight of antimony trioxide, 1.5 parts by weight of carbon black, γ-glycid 3 parts by weight of xypropyltrimethoxysilane, 400 parts by weight of quartz glass powder, and 5 parts by weight of a copolymer (I) of ethylene oxide and propylene oxide (molar ratio 1: 1, molecular weight 2000), ethylene oxide and propylene oxide as a flexible agent. Copolymer (molar ratio 1: 1, molecular weight 200
0) and 10 parts by weight of polydimethylsiloxane (II) having a polyether content of 35% by weight and an epoxy equivalent of 3000 having side groups of epoxy groups, and using a heating roll having a diameter of 10 inches, a kneading temperature of 80 to Kneading was performed under the conditions of 90 ° C. and kneading time of 7 to 10 minutes. Then, it crushed using the Torai crusher, and the epoxy resin molding material was produced.

Example 2 44 parts by weight of the phenol-formaldehyde novolac resin of Example 1, 5 parts by weight of the copolymer (I) used as a flexing agent and 10 parts by weight of polydimethylsiloxane (II) were preliminarily used together with 0.5 part by weight of triphenylphosphine.
It was prepared in the same manner as in Example 1 except that the mixture was heated and mixed at 0 ° C. for 3 hours.

Example 3 As the flexible agent of Example 1, the molar ratio of the copolymer (I) was 1:
3. Polyether having 5 parts by weight of copolymer (III) having a molecular weight changed to 1000, a copolymer of ethylene oxide and propylene oxide (molar ratio 1: 3, molecular weight 1000) and an epoxy group as side chain groups. Polydimethylsiloxane having a content of 30% by weight and an epoxy equivalent of 2000 was prepared in the same manner as in Example 1 except that 10 parts by weight of IV was used.

Example 4 44 parts by weight of the phenol-formaldehyde novolac resin of Example 3, 5 parts by weight of the copolymer (III) used as a flexible agent and 10 parts by weight of polydimethylsiloxane (IV) were previously added to 0.5 parts by weight of triphenylphosphine. Example 3 except that the mixture was heated and mixed at 150 ° C. for 3 hours.
Was prepared in the same manner as in.

Comparative Example 1 The procedure of Example 1 was repeated except that the flexible agents (I) and (II) of Example 1 were omitted.

Comparative Example 2 Comparative Example 1 was prepared in the same manner as in Example 1 except that 15 parts by weight of the flexible agent (I) used in Example 1 was used.

Comparative Example 3 A comparative example 1 was prepared in the same manner as in Example 1 except that 15 parts by weight of the flexible agent (IV) used in Example 3 was used. Table 1 shows the characteristics of the molding materials obtained in Examples and Comparative Examples, and Table 2 shows the details of the characteristic evaluation method.

As a result, the molding materials obtained in Examples 1 to 4 have markedly improved thermal shock resistance as compared with Comparative Example 1 in which no flexible agent is added, and the moldability such as appearance and burrs of the molded product is good, There is little decrease in the glass transition temperature, which is an index of sex. On the other hand, Comparative Examples 2 and 3 in which the component (C) or the component (D) of the present invention is used alone have drawbacks.

Therefore, by using the component (C) and the component (D) together as in Examples, a molding material having excellent moldability and heat resistance and excellent thermal shock resistance can be obtained.

〔The invention's effect〕

When an electronic component such as an IC and an LSI is encapsulated using the epoxy resin molding material for encapsulating an electronic component obtained by the present invention, an incompatible flexible agent is used for the resin as shown in the examples. There is no problem of moldability such as deterioration of the appearance of the molded product which is likely to occur at that time, and a product excellent in heat resistance and thermal shock resistance can be obtained, and its industrial value is great.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location H01L 23/31 (72) Inventor Fumio Furusawa 1500 Ogawa, Shimodate-shi, Ibaraki Hitachi Chemical Co., Ltd. Shimodate In the laboratory (72) Inventor Shigeki Ichimura 1500 Ogawa, Ogawa, Shimodate-shi, Ibaraki Hitachi Chemical Co., Ltd. Shimodate Laboratory

Claims (3)

[Claims] 1. (A) An epoxy resin having two or more epoxy groups in one molecule, (B) a compound having two or more phenolic hydroxyl groups in one molecule, (C) a polyalkylene ether compound, and (C) D) An epoxy resin molding material for electronic part encapsulation, which comprises a silicone polymer having an epoxy group and a polyalkylene ether group as an essential component. 2. The component (B), the component (C) and the component (D) are heated and mixed in advance in the presence of a curing accelerator that accelerates the reaction between the epoxy group and the phenolic hydroxyl group.
An epoxy resin molding material for encapsulating an electronic component as described above. 3. The polyalkylene ether groups of the components (C) and (D) are represented by the general formula The epoxy resin molding for encapsulating an electronic component according to claim 1 or 2, wherein the epoxy resin molding is a group having a skeleton having a structure represented by (where a and b are numbers satisfying the relationship of 0.2 ≦ a / b ≦ 5). material.