JPH059265A - Sealing resin composition and semiconductor-sealing apparatus - Google Patents

Abstract

PURPOSE:To prepare the title compsn. which is excellent in resistance to heat and soldering heat and can be guaranteed of long-term reliability by compounding a specific epoxy resin, a phenol resin having a cyclic terpene backbone, and a specified amt. of an inorg. filler. CONSTITUTION:The title compsn. is prepd. by compounding an epoxy resin of formula I (wherein n is 0, 1, or higher) (e.g. a resin of formula II). a phenol resin having a terpene backbone (e.g. a resin of formula III), and an inorg. filler (e.g. a silica powder) in an amt. of 25-90wt.% of the compsn. A mold release agent (e.g. a natural or synthetic wax, or a metal salt of a linear fatty acid). a flame retardant (e.g. antimony trioxide), etc., may be added if necessary. The compsn. can be used for sealing a semiconductor device as well as for sealing, coating, or insulating an electric or electronic part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing resin composition having excellent moisture resistance and solder heat resistance, and a semiconductor sealing device.

[0002]

2. Description of the Related Art In recent years, in the field of semiconductor integrated circuits,
At the same time as technology development for high integration and high reliability, automation of the mounting process of semiconductor devices is being promoted. For example, when mounting a flat package type semiconductor device on a circuit board, conventionally, soldering is performed for each lead pin, but recently, a solder dipping method or a solder reflow method has been adopted.

[0003]

A semiconductor device sealed with a conventional resin composition comprising an epoxy resin such as a novolac type epoxy resin, a novolac type phenolic resin and silica powder has a moisture resistance when the entire device is immersed in a solder bath. There was a drawback that the property deteriorated. Particularly when a semiconductor device that has absorbed moisture is immersed, peeling between the encapsulating resin and the semiconductor chip and between the encapsulating resin and the lead frame causes internal resin cracking, resulting in significant deterioration in moisture resistance. Leakage current, resulting in
The semiconductor device has a drawback in that it cannot guarantee long-term reliability.

The present invention has been made in order to solve the above-mentioned drawbacks, has little influence of moisture absorption, and is particularly excellent in moisture resistance and solder heat resistance after being immersed in a solder bath. A resin composition for encapsulation and a semiconductor encapsulation device capable of ensuring long-term reliability without peeling of the resin and the lead frame or generation of internal resin cracks, and without occurrence of wire breakage due to electrode corrosion or leakage current due to moisture. It is the one we are trying to provide.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that by using a specific epoxy resin or a phenol resin having a cyclic terpene skeleton, moisture resistance, solder The present invention has been completed by finding that a resin composition having excellent heat resistance can be obtained.

That is, the present invention provides (A) an epoxy resin represented by the following formula:

[0007]

[Chemical 3] (However, in the formula, n represents 0 or an integer of 1 or more), (B)
Phenolic resin having cyclic terpene skeleton and (C)
A resin composition for encapsulation, comprising an inorganic filler as an essential component and the inorganic filler (C) in an amount of 25 to 90% by weight based on the resin composition. A semiconductor encapsulation device is obtained by encapsulating a semiconductor device with a cured product of the encapsulating resin composition.

The present invention will be described in detail below.

As the epoxy resin (A) used in the present invention, those represented by the above formula are used, and the epoxy resin can be used without being limited by the molecular weight and the like. For example

[0010]

[Chemical 4] Is mentioned. In addition, a novolac-based epoxy resin or an epibis-based epoxy resin can be used in combination with this epoxy resin.

Examples of the phenol resin having a cyclic terpene skeleton (B) used in the present invention include those represented by Chemical formula 5, and the molecular structure and molecular weight thereof are not particularly limited. The terpene compound for introducing the cyclic terpene skeleton is a compound obtained by reacting a phenol with a terpene compound, p-mentha-2,8, (9) -diene, terpinolene, α-
Examples include terpene compounds such as terpinolene.

[0012]

[Chemical 5] (However, in the formula, n represents an integer of 1 or more.) Further, this resin includes a novolac type phenol resin obtained by reacting phenols such as phenol and alkylphenol with formaldehyde or paraformaldehyde, and modified resins thereof. It can be mixed and used.

As the inorganic filler (C) used in the present invention, generally used ones are widely used. Among them, silica powder having a low impurity concentration and an average particle diameter of 30 μm or less is preferably used. . If the average particle size exceeds 30 μm, the moisture resistance and the moldability are deteriorated, which is not preferable. The blending ratio of the inorganic filler is 50 to the whole resin composition.
It is preferable to contain 90% by weight. 50% by weight
When it is less than 100% by weight, the resin composition has a high hygroscopicity and is inferior in moisture resistance after immersion in solder, and when it exceeds 90% by weight, the fluidity is extremely poor and the moldability is inferior, which is not preferable.

The encapsulating resin composition of the present invention contains the above-mentioned specific epoxy resin, phenol resin having a cyclic terpene skeleton, and an inorganic filler as essential components, but within a range not deviating from the object of the present invention. If necessary, for example, natural waxes, synthetic waxes, metal salts of linear fatty acids, acid amides, esters, release agents such as paraffin, flame retardants such as antimony trioxide, colorants such as carbon black, silanes. A coupling agent, various curing accelerators, rubber-based or silicone-based low stress imparting agents, and the like can be appropriately added and blended.

The general method for preparing the encapsulating resin composition of the present invention as a molding material is to use the above-mentioned epoxy resin,
A phenol resin having a cyclic terpene skeleton, an inorganic filler, and the like are blended, and after sufficiently uniform mixing with a mixer or the like, further melt mixing treatment with a heat roll or mixing treatment with a kneader etc., followed by cooling and solidification to an appropriate size. It can be ground into a molding material. Further, the semiconductor encapsulation device of the present invention can be manufactured by transfer-injecting into a mold in which a semiconductor element is set using this molding material and curing it. The molding material can be used not only for sealing semiconductor elements but also for sealing or covering / insulating electronic parts or electric parts, and can impart excellent properties to them.

[0016]

In the encapsulating resin composition of the present invention, by using a specific epoxy resin and a phenol resin having a cyclic terpene skeleton, the glass transition temperature of the resin composition rises, thermomechanical properties and low stress Is improved, the occurrence of resin cracks after solder immersion and solder reflow is eliminated, and the deterioration of moisture resistance is reduced.

[0017]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to the following examples. In the following examples and comparative examples, “%” means “% by weight”.

Example 1 17% of the specific epoxy resin described above, 10% of a phenol resin having a cyclic terpene skeleton represented by the following formula,

[0019]

[Chemical 6] 72% silica powder, 0.3% hardening accelerator, ester wax
0.3% and a silane coupling agent 0.4% were mixed at room temperature, further kneaded and cooled at 90 to 95 ° C., and then pulverized to produce a molding material (A).

Example 2 Epoxy resin 9% used in Example 1, phenol resin having a cyclic terpene skeleton represented by the following formula 8%,

[0021]

[Chemical 7] Orthocresol novolac type epoxy resin 8%, silica powder 74%, curing accelerator 0.3%, ester wax 0.3
% And silane coupling agent 0.4% at room temperature,
After further kneading and cooling at 90 to 95 ° C., the mixture was pulverized to produce a molding material (B).

Comparative Example 1 Orthocresol Novolak type epoxy resin 17%, novolac type phenol resin 8%, silica powder 74%, curing accelerator 0.3%, ester wax 0.3% and silane coupling agent 0.4% were mixed and carried out. A molding material (C) was produced in the same manner as in Example 1.

Comparative Example 2 20% epibis type epoxy resin (epoxy equivalent 450), 5% novolac type phenol resin, 74% silica powder, 0.3% curing accelerator, 0.3% ester wax and 0.4% silane coupling agent were mixed. Then, a molding material (D) was produced in the same manner as in Example 1.

Molding materials (A) to (D) thus produced
Was used to transfer and inject into a mold heated to 170 ° C. and cured to manufacture a semiconductor device in which a semiconductor element was sealed. The characteristics of these semiconductor devices were tested, and the results are shown in Table 1. The encapsulating resin composition and the semiconductor device of the present invention are excellent in moisture resistance and solder heat resistance, and the remarkable features of the present invention. I was able to confirm the effect.

[0025]

[Table 1] * 1: Diameter 50 mm, thickness 3 mm by transfer molding
The molded product of Fig. 4 was left in saturated steam at 127 ° C and 2.5 atm for 24 hours and measured by the increased weight. * 2: A molded product similar to the case of water absorption was made and
After curing for a period of time, a test piece of an appropriate size was prepared and measured using a thermomechanical analyzer. * 3: Tested according to JIS-K-6911. * 4: Using molding material, 2 Silicon chips having at least two aluminum wirings were bonded to a normal 42 alloy frame, transfer molded at 175 ° C for 2 minutes, and then post-cured at 175 ° C for 8 hours. The molded product thus obtained was previously subjected to moisture absorption treatment at 40 ° C., 90% RH for 100 hours, and then immersed in a solder bath at 250 ° C. for 10 seconds. Then 127
A pressure cooker test was performed in saturated steam at 2.5 ° C at 2.5 ° C, and the disconnection due to corrosion of aluminum was evaluated as a failure. * 5: 8 × 8mm dummy chip was used for QFP (14 × 14 × 1.4mm).
) After packaging in a package and transfer molding using the molding material for 2 minutes at 175 ° C, post-curing was performed at 175 ° C for 8 hours. The semiconductor device manufactured in this way is
After absorbing moisture for 24 hours, it was immersed in a solder bath at 240 ° C for 1 minute. After that, observe the package surface with a stereomicroscope,
The occurrence of external resin cracks was evaluated.

[0026]

As is clear from the above description and Table 1, the encapsulating resin composition and the semiconductor encapsulating device of the present invention are excellent in moisture resistance and solder heat resistance, less affected by moisture absorption, and less susceptible to electrode formation. It is possible to remarkably reduce disconnection due to corrosion and generation of leak current due to moisture, and moreover, reliability can be guaranteed for a long period of time.

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Claims (2)

[Claims] 1. An epoxy resin represented by the following formula (A): (Wherein n represents 0 or an integer of 1 or more), (B) a phenol resin having a cyclic terpene skeleton and (C) an inorganic filler as essential components, and the (C) inorganic filler as a resin composition. The resin composition for encapsulation is characterized by being contained in a proportion of 25 to 90% by weight. 2. An epoxy resin represented by the following formula (A): (Wherein n represents 0 or an integer of 1 or more), (B) a phenol resin having a cyclic terpene skeleton and (C) an inorganic filler as essential components, and the (C) inorganic filler as a resin composition. The semiconductor encapsulation device is characterized in that the semiconductor device is encapsulated with a cured product of the encapsulation resin composition contained in a proportion of 25 to 90% by weight.