JPH0321637A - Resin for sealing - Google Patents

Abstract

PURPOSE:To obtain a semiconductor-sealing resin having high glass transition point and excellent moisture resistance, compatibility and low-stress characteristics by reacting a bismaleimide with a diaminopolysiloxane in the presence of polyfunctional polyallylphenols. CONSTITUTION:The objective resin can be produced by reacting (A) 100 pts.wt. of a bismaleimide of formula I (R1 is bivalent aromatic group) (e.g. N,N'-m- phenylenebismaleimide) with (B) 5-50 pts.wt. of a diaminopolysiloxane of formula II (R2 is alkylene or phenylene; R3 and R4 are alkyl or phenyl; n is 1-100) in the presence of a polyfunctional polyallylphenol of formula III [R5 is -O-, -CH2-, group of formula IV, -SO2- or -C(O)-; n is 0-10] preferably at 100-200 deg.C.

Description

[Detailed Description of the Invention] (Field of Application of the Invention) The present invention relates to a resin for semiconductor encapsulation that has a high glass transition point (hereinafter referred to as Tg), excellent moisture resistance, compatibility, and low stress properties. be.

(Prior art) In recent years, epoxy resin composites have been used in large quantities and most commonly for encapsulating semiconductor elements such as transistors and diodes, electronic circuits, etc. due to their characteristics, cost, etc. ing.

However, as electronic components are becoming more mass-producible, more highly integrated, and more surface-mounted, demands on sealing resins are becoming more severe.

Solder immersion (200 to 30
0° C.), cracks are likely to occur in devices, and in order to improve reliability, it is strongly desired that resins for semiconductor encapsulation have low stress characteristics and heat resistance.

Currently, epoxy resins are the mainstream resin for semiconductor encapsulation, but no resin has yet been found that is satisfactory in terms of moisture resistance and low stress properties.

To deal with these problems, attempts have been made to make epoxy resins have low stress characteristics by adding silicone compounds or using silicone-modified epoxy resins, but in terms of heat resistance, as long as epoxy resins are used, there are no improvements. There are limits to this, and high reliability after solder immersion during surface mounting has not been achieved.

In order to deal with these solder heat resistance, it is desired that the resin properties be low stress and high Tg that is higher than the solder bath temperature. Maleimide resins have been attracting attention as a resin with high heat resistance to replace epoxy resins, but they have the drawbacks of poor low stress properties, hardness, and brittleness.

Although the drawbacks of polyaminomaleimide resins such as hardness and brittleness have been improved, they are still insufficient in terms of low stress properties.

Example of reacting polymaleimide with anolephenols or alkenyl 7-enol ethers in the presence of a polymerization catalyst (JP-A-52-994; JP-A-Sho 58-
117219), but like polyaminomaleimide resins, they have the disadvantage of poor low stress properties.

Attempts have been made to add various silicone compounds as a measure to improve the low stress properties of maleimide resins including polyaminomaleimide resins, but the compatibility is extremely poor and phase separation occurs, making it impossible to obtain homogeneous resins.

In particular, when silicone oil is used, oil bleeds, resulting in roll slippage and mold staining. Also, if silicone rubber is used, the adhesion will decrease.

In order to improve compatibility, -OH group and 100H are added at the terminal.
Example of adding a silicone compound having a reactive group such as an I group (Brit UK PAT2018802 (1984)
). FR2544325, JP-A-57-90827.5
6-20023.57-90012.58-74749
However, gas is generated during molding, resulting in cracking and deterioration of heat resistance and moisture resistance, resulting in unsatisfactory performance.

Also, an example of reacting bismaleimide, diamine, and amino group-containing polysiloxane in a solution (Japanese Patent Application Laid-Open No. 62-246
No. 933) has also been attempted.

However, in the absence of a solvent, the compatibility of the polysiloxane containing amide 7 groups with bismaleimide and diamine is poor, and a homogeneous resin cannot be obtained.

The use of a solvent improves compatibility, but it is difficult to completely remove the solvent at the end of the reaction, resulting in decreased storage stability and the generation of gas, chloride, etc. during molding.
Many practical problems remain.

(Objective of the Invention) The object of the present invention is to have good compatibility, excellent moisture resistance and low stress characteristics, high heat resistance, and high reliability after soldering immersion without deteriorating general characteristics. An object of the present invention is to provide a resin for semiconductor encapsulation that is extremely excellent in semiconductor encapsulation.

(Structure 1 of the invention) The present invention combines a bismaleimide represented by the following formula CI) and a diamino polysiloxane represented by the following formula (n) into a polyfunctional polyallylphenol represented by the following formula [■] It is a sealing resin made by reacting in the presence of.

(Function) The bismaleimide resin used in the present invention is represented by the following formula (I).

R1: Divalent aromatic group Specific examples include N,N'-m-phenylenebismaleimide, N,N'-p-7enylenebismaleimide}', N
．． N'-+m-toluylene bismaleimide, N,N'-
4.4'-biphenylene bismaleimide, N. N'-4
．． 4'-(3.3'-dimethyl-biphenylene]bismaleimide, N,N'-4.4'-(3.3'-dimethyldiphenylmethane)bismaleimide, N.N'-4.4
'-(3.3'-diethyldiphenylmethane]bismaleimide, N,N'-4.4'-diphenylmethane bismaleimide, N,N'-4.4'-diphenylprono-bismaleimide F, N, Examples include N'-4,4'-cyphenyl ether bismaleimide, N,N'-3,3'-diphenylsulfone bismaleimide, N,N'-4,4'-diphenylsulfone bismaleimide, and the like. Yes, there is no problem even if two or more of these are included.

The diamino polysiloxane used in the present invention has the following formula (
II), whose degree of polymerization is n
ranges from 1 to 100.

R2: alkylene group or 7-enylene group R3. R4: when the alkyl group or phenyl group polymerization degree is 100 or more,
Compatibility will decrease. Diaminopolysiloxane is preferably used in an amount of 5 to 50 parts by weight per 100 parts by weight of bismaleimide.

If it is less than 5 parts by weight, the low stress effect of the cured resin decreases, and
If it is 50 parts by weight or more, the compatibility will deteriorate and the strength will decrease.

The polyfunctional polyarylphenol is represented by the following formula (III), and its degree of polymerization m is in the range of O-to.

0 SO2 1- and 101 When the degree of polymerization m is greater than 1O, the melting point is high, the workability is poor, and the strength of the cured resin is reduced.

Polyfunctional polyallylphenol is bismaleimide 10
It is preferably 5 to 50 parts by weight relative to 0 parts by weight. If it is less than 5 parts by weight, the compatibility will decrease, and if it is more than 50 parts by weight, the heat resistance of the cured resin will decrease.

Bismaleimide (A) and diaminopolysiloxane (B)
The reaction method for polyfunctional polyallylphenols (C)
The end point of the reaction is when the melting point of the reacted resin upon cooling is 50 to 120°C.
Allow the reaction to occur within the range of ℃.

In addition, in order to make a molded material using resin, a curing accelerator, epoxy resin, inorganic filler, lubricant, flame retardant, mold release agent, silane coupling agent, etc. are appropriately mixed and added, and the mixture is heated and kneaded. It can be made into a material by doing this.

A general method for manufacturing the semiconductor encapsulating resin composition of the present invention as a molded material is to add various additives to these essential ingredients and mix them uniformly, then heat the composite for 21 minutes. The mixture is kneaded using rolls, etc., cooled, and then pulverized to form a molding material.

If the obtained hollow material is used for encapsulating a semiconductor, it is possible to obtain a resin assembly for semiconductor encapsulation which has a high Tg, excellent low stress characteristics, and is extremely reliable.

(Example) Examples 1 to 3 Diaminopolysiloxane and o, o' in the formulation shown in Table 1
- diallylbis7enol A is heated and dissolved, and N. N'-4.4'-diphenylmethane bismaleimide was added and reacted for 20 minutes to obtain a homogeneous silicone-modified maleimide resin with a melting point of 60 to 80°C.

Comparative examples 1 to 5 The reaction was carried out in the same manner as in the examples using the formulations shown in Table 1.

Comparative Examples 1.3.5 had poor compatibility, and a homogeneous resin could not be obtained.

Examples 4 to 6 As shown in Table 2, silica powder, curing accelerator, aminosilane, coloring agent, and mold release agent were blended with the silicone-modified maleimide resin obtained in Examples 1 to 3, and the mixture was kneaded with a hot roll and then rolled. The shaped material was obtained.

The obtained molding material was heated to 180°C by transfer molding.
, a glossy precept-shaped article with no scratches was obtained after being shaped in 3 minutes. This molded product was further heated to 180℃. After curing for 8 hours, the properties were evaluated. The results are shown in Table 2.

Comparative Example 6.7 The resins of Comparative Examples 2 and 4 were molded in the same manner as shown in Table 2 and their properties were evaluated. The results are shown in Table 1.

The shaped materials of Examples 4 to 6 using the resins of Examples 1 to 3 have a small bending modulus at room temperature, low stress, and small internal stress. Moreover, it has a high glass transition temperature, high bending strength at 250°C, and excellent heat resistance and solder crank resistance.

(Margins below) (Effects of the invention) The cured product using the resin composition for semiconductor encapsulation according to the present invention has a high Tg and is excellent in moisture resistance and strength under heat, so that the durability of the encapsulated body is improved. It has good solder cracking properties, low stress, and excellent heat cycle resistance, making it an excellent and highly reliable resin composite for semiconductor encapsulation.

Claims (1)

[Claims] (1) (A) 100 parts by weight of bismaleimide represented by the following formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. are available▼・・・・・・[I] R_1: Divalent aromatic group (B) The following formula 5 to 50 parts by weight of diamino polysiloxane represented by [II] ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼... [II] R_2: Alkylene group or phenylene group R_3, R_4: Alkyl group or phenyl group n: 1-1
Integer of 00 (C) 5 to 50 parts by weight of polyfunctional polyallylphenols represented by the following formula [III] ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ ... [III] R_5: ▲ Numerical formulas, chemical formulas, There are tables, etc. ▼ n: A sealing resin made by reacting (A) and (B), an integer between 0 and 10, in the coexistence of (C).