JP2803057B2 - Sealing resin composition and semiconductor sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a sealing resin composition for semiconductor integrated circuits and the like having excellent moisture resistance and adhesion, and a sealing device therefor.

(Prior Art) In recent years, in the field of semiconductor integrated circuits, high integration,
High reliability technology is being developed. In the assembly process of electronic components and electronic devices, automation of a process of mounting a semiconductor product on a printed wiring board has been promoted in order to improve productivity. For example, as a method of mounting a semiconductor product on a printed wiring board, soldering was conventionally performed for each lead pin, but recently, after applying creamy solder to the lead pins in advance, the entire printed wiring board is heated to about 200 to 260 ° C. The mainstream is a reflow soldering method in which the solder is heated by soldering.

(Problems to be Solved by the Invention) However, a conventional semiconductor device sealed with a resin composition composed of an epoxy resin, a novolak-type phenol resin, and silica powder deteriorates in moisture resistance when soldered by a reflow method or the like. There was a disadvantage. In particular, when the same soldering is performed on a semiconductor device that has absorbed moisture, peeling occurs at the interface between the sealing resin and the semiconductor chip or between the sealing resin and the lead frame due to the steam pressure at a high temperature. This causes a drawback that a long-term reliability cannot be guaranteed.
On the other hand, in order to improve these disadvantages, there is a method in which a polyimide film is formed on the surface of the semiconductor chip to prevent the adhesiveness between the sealing resin and the semiconductor chip from deteriorating. The stopped semiconductor product has a drawback that when soldered, the moisture resistance deteriorates. For this reason, there has been a strong demand for the development of a sealing resin that is less affected by moisture absorption and has less deterioration in moisture resistance even when a semiconductor device is soldered, and a semiconductor sealing device therefor.

The present invention has been made to solve the above-mentioned drawbacks and to meet the demand, and has a small influence of moisture absorption, and particularly, a sealing resin composition having excellent moisture resistance and adhesion after soldering, and a semiconductor sealing material therefor. It is intended to provide a stop device.

[Constitution of the Invention] (Means and Actions for Solving the Problems) The present inventors have made intensive studies to achieve the above object, and as a result, have found that a specific coupling agent and a curing accelerator and a specific amount It has been found that the moisture resistance and the adhesion are improved by adding the silica powder of the present invention, and the present invention has been completed. That is, the present invention provides (A) an epoxy resin, (B) a novolak-type phenol resin, and (C) a coupling agent represented by the following structural formula. (Wherein, R represents a methyl group or an ethyl group) (D) 1,8-diaza-bicyclo- (5,
4,0) Undecene-7 or a derivative thereof (E) silica powder An essential component, a resin composition for sealing comprising 65 to 90% by weight of the silica powder of (E) with respect to the resin composition. is there. Further, depending on the cured product of the sealing resin composition,
This is a semiconductor sealing device in which the semiconductor device is sealed.

 Hereinafter, the present invention will be described in detail.

The epoxy resin (A) used in the present invention is not particularly limited in molecular structure, molecular weight, etc., as long as it is a compound having at least two epoxy groups in its molecule, and widely includes commonly used resins. Can be. For example, resins such as bisphenol-type aromatic resins, cyclohexane derivative alicyclic compounds, and epoxy novolak resins represented by the following general formulas are exemplified.

(In the formula, R ¹ represents a hydrogen atom, a halogen atom or an alkyl group, R ² represents a hydrogen atom or an alkyl group, and n represents an integer of 1 or more.) These epoxy resins can be used alone or in combination of two or more.

As the novolak type phenol resin (B) used in the present invention, a novolak type phenol resin obtained by reacting a phenol such as phenol or alkylphenol with formaldehyde or paraformaldehyde, and a modified resin thereof, for example, epoxidized or Examples thereof include a butylated novolak phenolic resin and a silicone-modified phenolic resin. As long as the novolak-type phenolic resin is used, it can be widely used without any particular limitation. And these novolak type phenolic resins are
They can be used alone or in combination of two or more.

The coupling agent (C) used in the present invention is represented by the following formula.

(Wherein, R represents a methyl group or an ethyl group) Specific examples thereof include, for example, A-1160 (trade name, manufactured by Nippon Unicar Co., Ltd.) and the like, alone or in combination of two or more. Can be used.

As the (D) curing accelerator used in the present invention, 1,8-diaza-bicyclo- (5,4,0) undecene-7 and derivatives thereof include, in addition to those represented by the following formula, Examples thereof include phenol salts, octylates, toluenesulfonates, oxophthalates, and partial salts of phenol novolak resins, and these can be used alone or as a mixture of two or more.

In the present invention, the use of the specific coupling agent and the curing accelerator improves the adhesiveness between the sealing resin composition and the semiconductor chip, and the adhesiveness between the sealing resin and the lead frame. Therefore, even when soldering, there is an effect that adhesion deterioration is very small, and as a result, moisture resistance hardly decreases. In particular, the effect of improving the moisture resistance of a semiconductor chip coated with a polyimide film is remarkable, but the same effect can be obtained of a semiconductor chip having passivated ordinary phosphosilicate glass or nitride film.

As the (E) silica powder used in the present invention, commercially available silica powder is generally used. Among them, those having a low impurity content and an average particle diameter of 30 μm or less are preferable. If the average particle size exceeds 30 μm, the moisture resistance and moldability are poor, which is not preferable. Regardless of the shape of the silica powder, whether it is a normal crushed shape or a spherical shape, the effect does not change, and there is no particular limitation. The mixing ratio of the silica powder is
It is desirable to contain 65 to 90% by weight based on the resin composition. If the proportion is less than 65% by weight, the amount of moisture absorption increases,
It is not preferable because of poor moisture resistance after soldering. On the other hand, if it exceeds 90% by weight, the fluidity is extremely poor and the moldability is poor, which is not preferred. Therefore, it is limited within the above range.

The resin composition of the present invention comprises (A) an epoxy resin, (B)
Novolak type phenolic resin, (C) coupling agent,
Although (D) a curing accelerator and (E) silica powder are essential components, for example, waxes, synthetic waxes, metal salts of straight-chain fatty acids, acid Release agents such as amides, esters, and paraffin, flame retardants such as antimony trioxide, and colorants such as carbon black can be appropriately added and blended.

As a general method for preparing the encapsulating resin composition of the present invention as a molding material, an epoxy resin, a novolak type phenol resin, a coupling agent, a curing accelerator, a silica powder, and the like are blended, and a mixer or the like is used. After mixing sufficiently uniformly, a melt-mixing treatment using a hot roll or a mixing treatment using a kneader or the like is performed, and then the mixture is solidified by cooling and pulverized to an appropriate size to obtain a molding material.

Then, the molding material is applied to coating, insulation, and the like for sealing electronic components such as semiconductor devices, so that excellent characteristics and reliability can be imparted.

The semiconductor encapsulation device of the present invention can be easily manufactured by encapsulating a semiconductor device using the above resin composition for encapsulation. The most common sealing method is a low pressure transfer molding method, but sealing by injection molding, compression molding, casting or the like is also possible. The sealing resin composition is heated and cured at the time of sealing, and finally a semiconductor sealing device sealed with the curing agent of this composition is obtained. The curing is desirably heated to 150 ° C. or higher. The semiconductor device for sealing is, for example, an integrated circuit, a large-sized integrated circuit, a transistor, a thyristor, a diode, or the like, and is not particularly limited.

(Examples) Hereinafter, examples of the present invention will be described together with comparative examples, but the present invention is not limited to the following examples.

Example After mixing epoxy resin, novolak type phenol resin, coupling agent, curing accelerator, silica powder, mold release agent, etc. at room temperature according to the composition shown in Table 1, kneading at 90-95 ° C. and cooling And pulverized to obtain a molding material.

Comparative Examples 1-2 Molding materials were produced in the same manner as in the examples, with the compositions in which the coupling agent and the curing accelerator were changed as shown in Table 1.

Using the molding materials produced in Examples and Comparative Examples 1 and 2, a semiconductor device was sealed and heated and cured at 170 ° C. to produce a semiconductor sealing device. Various tests were conducted on this molding material and the semiconductor sealing device. The results are shown in Table 1. The present invention was excellent in moisture resistance and adhesion, and the effects of the present invention were recognized.

Test methods performed on the examples and comparative examples will be described.

The water absorption was determined by transfer molding to prepare a molded product having a diameter of 50 mm and a thickness of 3 mm, leaving it in saturated steam at 127 ° C. and 2.5 atm for 24 hours, and increasing the weight.
The glass transition temperature is the same as that of water absorption.
After post-curing at 175 ° C. for 8 hours, a rod-shaped test piece of 5 × 5 × 17 mm was measured using a thermomechanical analyzer. Adhesion was performed by transfer molding using a molding material to manufacture a semiconductor device, and after immersion in a 260 ° C solder bath for 10 seconds,
Using a push-pull gauge, the shear peel strength with the resin for semiconductor device sealing was measured and determined. Moisture resistance is measured by bonding a silicon chip (test chip) with two aluminum wires to a 42 alloy frame using a molding material.
Transfer molding at 175 ° C for 2 minutes, 5 × 10 × 1.5mm
An SOP (Small Outline Package) type sealing device was obtained. The 20 sealing devices were preliminarily subjected to moisture absorption treatment at 40 ° C., 90% RH and 100 hours, and then immersed in a 260 ° C. solder bath for 10 seconds. Thereafter, a pressure cooker test (PCT) was performed in saturated steam at 127 ° C. and 2.5 atm, and a wire that was broken due to aluminum corrosion was evaluated as defective.

[Effects of the Invention] As is clear from the above description and Table 1, the sealing resin composition of the present invention and the semiconductor encapsulating device thereof are less affected by moisture absorption and have moisture resistance even after immersion in a solder bath. It is excellent in performance and adhesion, and does not cause disconnection due to electrode corrosion or leakage current due to moisture, and is highly reliable.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ identification code FI C08K 3:36 5:54) (58) Field surveyed (Int.Cl. ⁶ , DB name) C08L 63/00-63/10 C08G 59/62 C08G 59/56 H01L 23/29

Claims (2)

(57) [Claims] (A) an epoxy resin (B) a novolak-type phenol resin (C) a coupling agent represented by the following structural formula (Wherein, R represents a methyl group or an ethyl group) (D) 1,8-diaza-bicyclo- (5,
4,0) Undecene-7 or a derivative thereof (E) Silica powder An essential component, wherein the silica powder of (E) is contained in an amount of 65 to 90% by weight based on the resin composition. Resin composition. (A) an epoxy resin (B) a novolak-type phenol resin (C) a coupling agent represented by the following structural formula (Wherein, R represents a methyl group or an ethyl group) (D) 1,8-diaza-bicyclo- (5,
4,0) Undecene-7 or a derivative thereof (E) Silica powder An essential component, and a resin composition for sealing comprising 65 to 90% by weight of the silica powder of (E) with respect to the resin composition. A semiconductor sealing device, wherein a semiconductor device is sealed with a cured product.