JPH0366724A - Epoxy resin composition for sealing semiconductor - Google Patents

Abstract

PURPOSE:To provide the subject composition comprising an epoxy resin, a phenolic resin, a specific cyclic phenol compound and an inorganic filler, capable of obtaining a cured product having high glass transition temperature and excellent heat resistance, moisture resistance and cold heat impact resistance. CONSTITUTION:The objective composition comprises (A) an epoxy resin having two or more epoxy groups in one molecule (preferably a novolak-based or triglycidylphenylmethane-based epoxy resin), (B) a phenolic resin having two or more phenolic hydroxyl groups in one molecule (preferably containing <=0.5wt.% of unreacted monomer), (C) a cyclic phenol compound of the formula [R is H or C(CH3)3; n is 4, 6 or 8] and (D) an inorganic filler (e.g. crystalline silica powder, alumina powder or talc) in a B/C weight ratio of 1.5-13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to an epoxy resin composition for semiconductor encapsulation. More specifically, by incorporating a phenol resin having two or more fζ hydroxyl groups in one molecule and a specific cyclic phenol compound in a specific ratio into the epoxy resin that serves as the base material, heat resistance, moisture resistance, and cold shock resistance are achieved. The present invention relates to an epoxy resin composition for semiconductor encapsulation with improved properties.

[Conventional technology]

It is already well known that semiconductor devices such as ICs and LSIs are encapsulated with silicone resin, epoxy resin, etc. Among these encapsulation resins, Japanese Patent Application Laid-Open No. 63-77930 As shown in the publication, an epoxy resin composition that combines a cresol novola solid epoxy resin as a base resin and a phenol novola solid epoxy resin as a hardening agent has excellent moisture resistance and high temperature properties after sealing. It has excellent electrical properties, moldability, etc., and is relatively inexpensive, so it is widely used.

However, with the increasing variety of mounting means in semiconductor devices such as IC, LSI, and other semiconductor devices, there is a trend toward smaller nitriding and thinning. As technology advances, the epoxy resin compositions used here are desired to have improved properties such as heat resistance, moisture resistance, low coefficient of expansion, low modulus of elasticity, and high glass transition temperature. Especially regarding heat resistance.

This trend is remarkable. For example, if the device is disposed in molten solder after being mounted on a substrate, problems may occur such as cracking in the sealing resin or variations in device characteristics.

Furthermore, it has been extremely difficult to apply this method to an element for mounting on a moving wheel, which requires heat resistance of 150° C. or higher.

Therefore, in order to improve heat resistance, for example, 'Rh hardening'i'NMM VoC8, No, 1, p25 (1
987), poly P-
The application of vinylphenol is being considered.

[Problem to be solved by the invention]

Improvement in heat resistance by the poly-p-vinylphenol described above may lead to a decrease in the fluidity of the resin composition, which may cause problems such as a decrease in moldability and failure to achieve satisfactory resin sealing. was there.

This invention was made in order to solve the above-mentioned problems, and provides an epoxy resin composition for pressure-resistant semiconductors that has secondary heat resistance, secondary moisture resistance, and cold shock resistance without reducing the moldability of the resin composition. The purpose is to provide the following.

[Means to solve the problem]

This invention provides: (4) an epoxy resin having two or more epoxy groups in one molecule, (mon) a phenol resin having two or more phenolic hydroxyl groups in one molecule, and C) a resin represented by the general formula (1). An epoxy for semiconductor encapsulation consisting of a cyclic phenol compound and D) an inorganic filler, characterized in that the weight ratio of the above component ε to the above C) component is in the range of (B)/(C)-ILL5 to 13. This is achieved by a resin composition.

[Effect]

The epoxy resin composition for semiconductor encapsulation of this invention is.

By containing a phenol resin having two or more phenolic hydroxyl groups in one molecule and a specific cyclic phenol compound in a specific ratio to the base epoxy resin, the fluidity of the resin composition is impaired. It has improved heat resistance, moisture resistance, and cold shock resistance.

〔Example〕

Examples of the epoxy resin (A) having two or more epoxy groups in one molecule used in this invention include Novola-Soku epoxy resin, triglycidylphenylmethane epoxy resin, and bisphenol A? Epoxy resin,
Various types of epoxy resins such as alicyclic epoxy resins can be mentioned, and among these, novo->noc type epoxy resins and triglycidylphenylmethane type epoxy resins are preferred because they have excellent Lt i = characteristics. These may be used alone or in combination of two or more.

Furthermore, if necessary, a brominated epoxy resin such as a brominated novola-soc type epoxy resin or a brominated bisphenol A type epoxy resin may be used in combination.

In this case, the amount of these brominated epoxy resins is preferably 50 parts by weight or less based on 100 parts by weight of the epoxy resin.

The phenolic resin having two or more phenolic hydroxyl groups in the (B) molecule used in this invention includes:
For example, it is obtained by condensing a phenolic compound such as phenol, cresol, xylenol, bisphenol A, or resorcinol with formaldehyde or/or formaldehyde under an acidic catalyst, and unreacted monomers are In phenolic resin, 0
．． It is preferably 5% by weight or less.

Used in this invention. 〇The cyclic phenol compound represented by the general formula (1) is.

In a solvent, in the presence of an alkali metal hydroxide,
It can be obtained by the condensation of p-4ert-butylphenol and paraformaldehyde or the synthesis of p-1ert-butylphenol and formaldehyde.

As the above-mentioned solvent, xylene, toluene, etc. can be used alone or in combination.

As the alkali metal hydroxide, potassium hydroxide, sodium hydroxide, rubidium hydroxide, etc. can be used.

It is a constituent component of the epoxy resin composition for semiconductor encapsulation according to the present invention. The blending ratio of the above middle) component and C) component is:
Weight ratio of medium 1/(C)-1,5 to 13, preferably 2 to
The range is 8. (If Bl/(C) is less than 1.5.

As the fluidity of the epoxy resin composition decreases, workability deteriorates, and if (B)/(C) exceeds 13, it is difficult to increase the , since heat resistance cannot be improved, both are preferable.

Used in this invention. 0 Inorganic fillers include, for example, crystalline silica powder, fused silica powder, alumina powder, talc,
Examples include quartz glass powder, calcium carbonate powder, and glass fiber fl. The amount of these inorganic fillers added is preferably 50 to 85% CMIIE% (the same applies hereinafter) in the composition. If it is less than 50%, the effect of lowering the coefficient of linear expansion and curing shrinkage will be small, and if it exceeds 85%, fluidity will decrease and workability will tend to decrease.
It is preferable to select the blending amount appropriately within the range of 50 to 85% depending on the required properties.

Furthermore, the epoxy resin composition for semiconductor encapsulation according to the present invention may optionally contain an imidazole compound,
Tertiary amines, curing accelerators such as phosphorus compounds, coloring agents such as carbon black, mold release agents such as Carnapawa Sox, synthetic wax, etc., flame retardant aids such as antimony trioxide rJ, γ-glycide, etc. A strength/sopping agent such as siloxypropyltrimethoxysilane, a rubber component such as silicone rubber, fluororubber, etc. may be added to each of the compositions in an amount not exceeding 10% in the composition.

Furthermore, the epoxy resin composition for semiconductor encapsulation of the present invention includes:
It can be easily prepared using commonly used known mixing apparatuses, such as a tumbler, a roll, a kneader, a Leical machine, a Henschel mixer (trade name, manufactured by Mitsui Miike Seisakusho), and the like.

Next, examples of the epoxy resin composition for semiconductor encapsulation according to the present invention will be described in detail together with comparative examples thereof.

Production example of cyclic phenol compound p-t@rL-butylphenol 55°6gr, paraformaldehyde! 8gr, 0.8ml of 10N caustic potassium solution, and 300gr of xylene were placed in a 4-meter solo flask equipped with a water sampling tube, and heated to 120°C while stirring with a stirrer under a N2 gas stream.
The temperature was raised to +40C and reacted for 5 hours under xylene reflux,
A white precipitate was obtained. Collect this precipitate with a filter.

After washing with toluene, ether, acetone and ion-exchanged water, it was recrystallized from chloroform and dried under reduced pressure at 150°C for 8 hours.

As a result of measuring the properties of the compound obtained in this way,
It was confirmed that it was a cyclic phenol compound represented by the above general formula. Infrared absorption spectrum: 3300cm
Absorption based on IJ and OH groups, melting point: 411-412
°C, and elemental analysis 20, 81.45 (calculated value 8
1.44), H, 8,71 (calculated value 8.70) [Examples 1 to 6. Comparative Examples 1 to 5] Epoxy resins, curing agents, inorganic fillers, and other components were prepared to have the compositions shown in Table 1.

After kneading for 3 to 7 minutes with a hot roll at 80 to 110°C, the mixture is crushed and then processed using a press to produce 3100 to 1500 kg/
A tablet was prepared under a pressure of
Using the tabbouleh soto obtained in this way, the mold temperature was 180℃±5℃, and the plunger pressure was 80kg10n''.
, Transfer molding was performed under conditions of a molding time of 90gea, and various reliability evaluation monitor chips and various evaluation test pieces were applied to each of these reliability evaluation monitor chips and each evaluation test. 1 for each piece
A ghrO post-curing treatment was performed at 75°C.

In addition, using each evaluation test piece treated as described above, 1 flexural modulus 1 flexural strength, linear expansion coefficient.

Glass transition temperature and fluidity were each measured. The results are shown in Table 2 below.

Using each of the reliability evaluation monitors treated as described above, a heat resistance reliability test, a humidity resistance reliability test, and a deep cooling thermal shock test were conducted in the following manner. The results are shown in Table 3.

"Heat Resistance Reliability Test" The time required for the monitor chip to become defective was measured in air at 250°C.

・Moisture Resistance Reliability Test” PCT (Pressure Cooker Tes&
) % 1000hr under the conditions of 130℃ and 2.7 atm
Evaluation was made based on the number of defective monitor chips.

"Cold thermal shock resistance test" - 3Qmin at 65℃ and 30toin at 150℃
The evaluation was made based on the number of defective samples after 200 cycles.

That is, as can be seen from Table 2 above, when the epoxy resin composition for semiconductor encapsulation in this example is used, the basic properties such as the flexural modulus of elasticity 9 of the device itself and the coefficient of linear expansion, etc. As can be seen from Table 3 above, it is possible to increase the glass transition temperature without significantly changing the fluidity of the composition. It has extremely excellent properties.

〔Effect of the invention〕

As is clear from the above description, the epoxy resin composition for semiconductor encapsulation of the present invention uses phenol having two or more heptaenolic hydroxyl groups in one molecule as a curing agent for the epoxy resin serving as the base material. Since the resin and a specific cyclic phenol compound are contained in a specific ratio, the fluidity of the resin composition required for resin sealing such as resin-sealed pisocage is maintained, and the cured product itself is It has a high glass transition temperature and has excellent heat resistance, moisture resistance, and cold shock resistance.

Claims (1)

[Claims] (A) An epoxy resin having two or more epoxy groups in one molecule, (B) A phenol resin having two or more phenolic hydroxyl groups in one molecule, (C) General formula (1) ), and ▲ mathematical formulas, chemical formulas, tables, etc. ▼ (1) In the formula, R is a hydrogen atom or ▲ mathematical formulas, chemical formulas, tables, etc. ▼ represents the group [, n = 4, 6 Or it represents an integer of 8. ] (D) Consists of an inorganic filler, consisting of the above (B) component and the above (C)
1. An epoxy resin composition for semiconductor encapsulation, characterized in that the weight ratio of component (B)/(C) to component (B) is in the range of 1.5 to 13.