JPH05275572A - Semiconductor sealing resin composition - Google Patents

Abstract

PURPOSE:To provide a semiconductor sealing resin composition having excellent solder heat resistance, reliability and moldability. CONSTITUTION:A semiconductor sealing resin composition contains resin mixture obtained by previously mixing 20-100 pts.wt. of phenol series curing agent and curing accelerator in solvent and removing the solvent, 100 pts.wt. of epoxy resin and 300-2000 pts.wt. of filling silica and as main components.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for semiconductor encapsulation which is excellent in solder heat resistance, reliability and moldability.

[0002]

2. Description of the Related Art In recent years, high integration of semiconductor devices has been rapidly advanced, and the size of elements and the miniaturization of wiring width have been remarkably advanced. Currently, most of the semiconductor devices including these highly integrated semiconductor devices are resin-sealed. This is largely due to the development of a highly reliable sealing resin having excellent performance.

On the other hand, in mounting components on a printed circuit board, a DIP package which is an insertion type package has been changed to a SOP package which is a surface mounting type package for high-density mounting and streamlining of work.

Further, in recent years, in order to achieve higher density packaging, the SOP and QFP packages, which are the first generation of surface mount devices, are being shifted to TSOP and TQFP packages which have been made thinner.

With the thinning of the package, the resin thickness on the upper surface of the chip has become very thin. Therefore, cracking of the resin portion due to heating during mounting has become a more serious problem.

As a countermeasure, improvement of the sealing resin has been studied. For example, compounding the rubber component with the sealing resin,
There is a method of reducing the internal stress, a method of highly filling a filler to reduce the linear expansion coefficient, and the like (JP-A-63-1894)
21 gazette, Sho 63-16445 gazette). Further, a method has been proposed in which the surface of the filler is treated with a coupling agent to improve the adhesiveness at the interface between the resin and the filler and increase the strength (JP-A-61-221222). In addition, other components except the curing agent and the curing accelerator are melt-mixed in advance,
A method has also been proposed in which the strength is increased by cooling and then mixing the remaining components to improve the homogeneity (JP-A 3-1).
95764).

[0007]

In the above-mentioned prior art, the encapsulants improved by various methods have been gradually effective, but the higher solder heat resistance requirements have been met with the progress of mounting technology. Not enough to respond.

For example, the addition of the rubber component is an effective method for the SOP package which is the first generation of surface mounting, but it is still insufficient for the second generation TSOP and TQFP which are the second generation in recent years. In order to reduce the stress, compounding a rubber component causes a decrease in bending strength and a decrease in solder heat resistance. Furthermore, the addition of these softening agents leads to deterioration of water absorption characteristics, and lowers solder heat resistance for thin packages such as TSOP and TQFP.

In addition, in the method of filling the filler with a high amount, the high filling of crushed silica causes a decrease in fluidity, making molding difficult, and the use of spherical silica causes a decrease in strength. The effect of treating the filler surface with a coupling agent is also not sufficient to meet the demand.

In addition, the method of previously melt-mixing the components excluding the curing agent and the curing accelerator does not provide sufficient strength to meet the requirements in spite of complicated operations, and cracks during soldering should be completely prevented. I couldn't. Therefore, it is desired to develop a sealing resin that is more excellent in solder heat resistance.

An object of the present invention is to solve the above problems and provide a resin composition for semiconductor encapsulation which is excellent in solder heat resistance, reliability and moldability.

[0012]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventors have found that a phenolic curing agent and a curing accelerator are used as a mixture in which they are completely and uniformly dispersed in a solvent. The present invention has been completed based on the finding that it can be solved by improving the reactivity and the strength.

That is, the present invention is a resin composition for semiconductor encapsulation, which comprises a mixture obtained by previously mixing a curing agent and a curing accelerator in a solvent and then removing the solvent.

The mixing of the phenol novolac curing agent and the curing accelerator according to the present invention is carried out, for example, by dissolving 50 parts by weight of the phenol novolac curing agent in 300 parts by weight of acetone and adding the curing accelerator triphenylphosphine 1.0.
It is obtained by adding and dissolving parts by weight and completely removing the acetone by vacuum distillation after complete dissolution.

The epoxy resin is not particularly limited in molecular weight and structure as long as it has at least two epoxy groups. For example, phenol novolac type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin and the like are used.

As the phenol resin, for example, a usual phenol novolac resin, cresol novolac resin or the like is used. Also, for 100 parts of epoxy resin,
Phenolic resin is 30 to 80 parts, preferably, the ratio of epoxy equivalent to phenolic hydroxyl group equivalent is 1: 0.8 to.
It is desirable to set to 1.2. Other than this, curability,
Strength and water absorption properties are reduced, and solder heat resistance is reduced.

To maximize the effect of the present invention, the filler is added in an amount of 300 to 2000 parts by weight. If it is above this range, the fluidity will be lowered, and if it is below this range, the strength will be lowered and the desired effect cannot be obtained.

In the present invention, a curing accelerator is blended in addition to the epoxy resin curing agent. Known curing accelerators can be used, but suitable curing agents include, for example,
Examples include triphenylphosphine, imidazole, and 1,8-diazabicyclo (5,4,0) undecene-1. The amount of addition of triphenylphosphine is 0.5 to 100 parts by weight of the epoxy resin.
5 parts by weight is desirable.

In the resin composition for semiconductor encapsulation of the present invention, if necessary, a release agent such as OP wax and carnauba wax, a coupling agent such as γ-glycitoxypropyltrimethoxysilane, carbon black and the like. It is also possible to add a colorant, a flame retardant such as antimony trioxide.

The resin composition for semiconductor encapsulation of the present invention can be mixed, kneaded, pulverized, and then heat-molded according to a conventionally known method to obtain a semiconductor device having a semiconductor element enclosed therein.

[0021]

The present invention will be described in more detail below by showing Examples of the present invention. Example A phenol novolac curing agent (trade name: Tamanor 758; manufactured by Arakawa Chemical Co., Ltd., which is referred to as Phenolic Resin A) 350 parts (curing agent 50 parts by weight, acetone 300 parts by weight) previously dissolved in acetone was added to a curing accelerator. As a resin mixture A, 1.0 part by weight of triphenylphosphine was melt-mixed at 90 ° C., and then acetone was distilled off under reduced pressure.

Next, 100 parts of this resin mixture A and o-cresol novolac type epoxy resin (trade name YDCN-702; manufactured by Tohto Kasei Co., Ltd., which is referred to as Epoxy A), spherical fused silica powder having an average particle size of 21 μm, etc. After mixing the additives in the proportions shown in Table 1, the mixture was kneaded at 110 ° C. for 4 minutes using a mixing roll, cooled and pulverized to prepare a sealing resin composition. The spiral flow was measured using these sealing resin compositions. In addition, test pieces were prepared using the same resin composition for sealing, and bending strength and bending elastic modulus were measured. Furthermore, 84pin IC is molded,
After post-cure, after absorbing moisture for 24 hours, 48 hours, and 72 hours in a constant temperature and humidity chamber at 85 ° C. and 85%, measure the water absorption rate, and observe the peeling of the back surface of the die pad with an ultrasonic flaw detector. Immerse in a solder bath at 260 ° C for 10 seconds,
The cracks in the package were observed. These results are shown in Table 1.
Shown in.

Comparative Example 100 parts of epoxy resin A, 50 parts of phenol resin A, spherical fused silica powder having an average particle size of 21 μm, a curing accelerator (triphenylphosphine), and other additives were mixed in the proportions shown in Table 1, and then mixed. Using a roll, 110
The mixture was kneaded at 4 ° C. for 4 minutes, cooled, and then pulverized to prepare a sealing resin composition. Using these sealing resin compositions, Example 1
Each physical property was measured in the same manner as.

From the results shown in Table 1, it can be seen that the resin composition for semiconductor encapsulation of the present invention is excellent in strength and solder heat resistance.

[Table 1]

[0025]

As described above, when the resin composition of the present invention is used, it is possible to obtain a cured product having high strength and excellent solder heat resistance. Can be obtained.

Claims (2)

[Claims] 1. A resin composition for semiconductor encapsulation, comprising a mixture obtained by previously mixing a curing agent and a curing accelerator in a solvent and then removing the solvent. 2. A phenolic curing agent, 20 to 100 parts by weight, and a silica 30 for filling, relative to 100 parts by weight of an epoxy resin.
The resin composition for semiconductor encapsulation according to claim 1, wherein 0 to 2000 parts by weight is an essential component.