JPH01251625A - Resin sealed type semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the sedimentation separation of paste in a syringe, and avoid the corrosion disconnection of wiring, by bonding a semiconductor element to a lead frame, by using conductive paste containing high purity resin, low viscosity diluent and silver-plated copper conductive powder. CONSTITUTION:A semiconductor element is bonded to a lead frame, by using conductive paste containing high purity resin, low viscosity diluent and silver- plated copper conductive powder. High purity resin may be thermosetting or thermoplastic, but concentration of total chloride ion contained in the resin is desirable to be equal to or less than 300ppm. As to such a resin, e.g., phenol resin, epoxy resin, etc., can be mentioned. As to low viscosity diluent, e.g., glycidoxy system reactive diluent, dioxane, etc., can be mentioned. Compounding ratio of the low viscosity diluent is desirable to be 2-60wt.% for the total amount of the high purity resin and the low viscosity diluent. As for the silver- plated copper conductive powder, silver-plated phosphorus segment or copper powder whose average grain diameter is in the range of 1-8mum is desirable.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a resin-sealed semiconductor device using a conductive paste for mounting a semiconductor element. The present invention relates to a resin-sealed semiconductor device using a conductive paste.

(Prior art) IC and LS are placed on a predetermined portion of a thin metal plate (lead frame).
The process of bonding semiconductor pellets such as I is one of the important processes that affects the long-term reliability of the device. Traditionally, the Au-bonding method has been used to bond the silicon side of the pellet to the gold plated surface of the lead frame under heat.
The 3i eutectic method has been the mainstream, but in recent years there has been a rapid shift to methods using solder and resin-sealed semiconductor devices using conductive paste (adhesive).

However, although some methods using solder have been put into practical use, it has been pointed out that the solder and solder balls scatter and adhere to electrodes and the like, causing corrosion and disconnection. On the other hand, the method of using conductive paste, which usually uses an epoxy resin mixed with silver powder, has been put into practical use for about 10 years, but it has not been used as well as Au-3i in terms of reliability. Compared to the crystal method, satisfactory results could not be obtained. The method of using conductive paste has advantages such as superior heat resistance compared to the soldering method, but on the other hand, the resin and its hardener may accelerate corrosion of the aluminum electrode and cause disconnection. In many cases, the reliability of the device is AU-Si.
It was inferior to the eutectic method. Furthermore, in recent years, IC/LSI and L
As semiconductor devices such as EDs become larger, pellet cracks and reduced adhesive strength have become a problem, and the base material in the syringe has sedimented and separated during the semiconductor assembly process and during storage, reducing reliability. However, it was not possible to obtain a resin-sealed semiconductor device with a high temperature.

(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned circumstances, and it prevents the paste in the syringe from settling and separating during the semiconductor assembly process and storage, and prevents corrosion and disconnection of wiring. The present invention aims to provide a resin-sealed semiconductor device using a fast-curing conductive paste that has excellent adhesive properties and hydrolysis resistance, and has no voids in the bonding layer.

[Structure of the Invention (Means for Solving the Problems) As a result of extensive studies to achieve the above object, the present inventor found that by using a conductive paste having the composition described below,
The present invention has been completed by discovering that a highly reliable resin-encapsulated semiconductor device can be obtained that has excellent adhesiveness and hydrolysis resistance, and has no sedimentation and separation of the paste inside the syringe during the semiconductor assembly process or during storage. It is.

That is, the present invention provides a resin-sealed semiconductor device in which a semiconductor element is bonded onto a lead frame. The present invention is a resin-sealed semiconductor device characterized by bonding using adhesive paste.

The high-purity resin (A) used in the present invention may be either thermosetting or thermoplastic resin, but the total chlorine ion concentration contained in the resin is 300 pp11 or less, preferably 20 pp1.
It is desirable that it be 0 pIJ or less.

If the total chlorine ion concentration exceeds 300 ppm, it is undesirable because it corrodes the aluminum electrodes of the semiconductor element and reduces the reliability of the semiconductor device. As such resin,
For example, phenolic resin, epoxy resin, polyimide resin, polyamide resin, polyamideimide resin, polyesterimide resin, polyhydantoin resin, polybutadiene V! 1n￥f, petroleum ta1 fat, ABS resin, PP5vA
These include fats and the like, and these may be used alone or in a mixture of two or more.

Examples of the low-viscosity diluent (B) used in the present invention include glycidoxy-based reactive diluents, dioxane, hexane, benzene, toluene, solvent naphtha, industrial gasoline, acid cellosolve, ethyl cellosolve, butyl cellosolve acetate, butyl carpi Examples include toll acetate, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, diethylene glycol diethyl ether, and these may be used alone or in a mixture of two or more.

A low-viscosity diluent is added to high-purity resin and mixed.
If necessary, they may be partially bonded to each other by a heating reaction, and if necessary, a curing catalyst may be used. It is desirable that the amount is 2 to 60% by weight based on the total amount of the agent.

If the amount is less than 2% by weight, it is not effective in lowering the viscosity of the resin, and if it exceeds 60% by weight, the reactivity tends to be poor and voids tend to occur, which is not preferable.

As the silver-plated copper-based conductive powder (C) used in the present invention, it is preferable to use silver-plated copper powder having an average particle size in the range of 1 to 8 μm.

The conductive paste used in the present invention contains the above-mentioned (A) high-purity resin, (B) low-viscosity diluent, and (C) silver-plated copper-based conductive powder, and if necessary, an antifoaming agent and a coupling agent. Other additives can be added and blended. This conductive paste is produced by sufficiently mixing the above-mentioned components, then subjecting the mixture to a cross-wire treatment using, for example, two rolls, and then degassing under reduced pressure. The conductive paste produced in this way is filled into a syringe and discharged onto a lead frame using a dispenser to bond the semiconductor element, followed by wire bonding and sealing with an encapsulant to produce a resin-sealed semiconductor device. can do.

(Examples) Next, the present invention will be specifically explained by examples, but the present invention is not limited by these examples.
In Examples and Comparative Examples, "part j" means "gi, part J, unless otherwise specified."

Example 1 Epoxy 111 resin EP4400 (manufactured by Asahi Denka Co., Ltd., trade name) 7.6 parts, para-hydroxystyrene marcarine force-M (Marukubi Petrochemical Co., Ltd., trade name 25.6 parts, has a norbornene ring A dissolution reaction was carried out at 100°C for 1 hour with 0.2 parts of the resin Heptoxide 4000 (manufactured by Daicel Corporation, trade name), 10.4 parts of glycidoxypropyltrimethoxysilane, and 4.0 parts of diethylene glycol diethyl ether. , a viscous brown resin was obtained. This resin 27.8
A conductive paste was prepared by mixing 0.006 parts of 2PH2-CN (manufactured by Shikoku Kasei Kogyo Co., Ltd., trade name) as a catalyst and 70 parts of silver-plated copper-based conductive powder having an average particle size of 5 μm. Semiconductor elements are bonded using this conductive paste, wire bonded after curing, and sealed with an epoxy resin encapsulant to form a resin-sealed semiconductor device (
A> was obtained.

Example 2 23.7 parts of epoxy resin EOCN103S (manufactured by Nippon Kayaku Co., Ltd., trade name), 12.3 parts of parahydroxystyrene Marcalin Power-M (mentioned above), Finton #1700 (Japanese), a resin having a norbornene ring (manufactured by Zeon Co., Ltd., trade name) and 42.4 parts of diethylene glycol diethyl ether were subjected to a dissolution reaction at 100° C. for 1 hour to obtain a viscous brown resin. A conductive paste was prepared by mixing 27.8 parts of this resin with 0.006 parts of 2PH2-CN (described above) as a catalyst and 70 parts of silver-plated copper-based conductive powder having an average particle size of 5 μm.

Semiconductor elements were bonded using this conductive paste, hardened, wire bonded, and sealed with an epoxy resin sealant to obtain a resin-sealed semiconductor device (B).

Example 3 Polyimide resin solution (N
-Methyl 2-pyrrolidone solvent) to 166.7 parts, N
- A conductive paste was prepared by mixing 30 parts of methyl 2-pyrrolidone and 70 parts of a 5 μm silver-plated copper-based conductive powder. Semiconductor elements are bonded using this conductive paste, wire bonded after curing, and sealed with an epoxy resin encapsulant.
C) was obtained.

Comparative Example A resin-sealed semiconductor device (D) was obtained using a commercially available epoxy resin-based silver powder solvent-type conductive paste for semiconductors.

The conductive pastes used for manufacturing the resin-sealed semiconductor devices (A), (B), (C), and (D) obtained in Examples 1 to 3 and Comparative Examples were filled into a syringe, and a sedimentation separation test was performed. were carried out at 25°C and -10°C.

Furthermore, by using this syringe and dispenser
A 100-shot discharge variation test was conducted, and the semiconductor element and lead frame were bonded and hardened.

These were tested for adhesive strength and hydrolyzable CI ions of the conductive paste, and the reliability of the resin-sealed semiconductor device was also tested. The results are shown in Table 1, and it was possible to confirm the remarkable effects of the present invention.

*1: After leaving the paste in a 5cc syringe in an upright position, measure the distance from the top to the part that has settled and separated.2: Place 4InIllX, 'Ill on a lead frame (42 alloy) with silver plating removed. A silicon element was bonded and measurements were made using a push-pull gauge at each temperature.

*3: C1 extracted by curing conductive 1 paste under the adhesive conditions shown in Table 1, crushing it into 100 meshes, and heating and extracting at 180'C for 2 hours.

It was measured from the amount of Na ions.

*4: Layer temperature test (PCT) in water vapor at a temperature of 121°C and a pressure of 2 atm, and conduction with an applied voltage of 15 V DC in water vapor at a temperature of 120°C and a pressure of 2 atm) (wet type @ (bias-PCT) was conducted and evaluated on 60 samples of each resin-sealed semiconductor device.The evaluation method was as follows:
If the open or leakage current due to corrosion of the aluminum electrodes constituting the semiconductor element is 500% or more of the allowable value.
It was determined that the product was defective when the temperature increased, and the defective occurrence rate over time was shown.

[Effect of the invention] As is clear from the above explanation and Table 1.

The resin-sealed semiconductor device of the present invention uses a conductive paste that does not cause sedimentation and separation of the paste in the syringe during the semiconductor assembly process or during storage, so there is no corrosion or breakage of wiring.2. A highly reliable resin-sealed semiconductor device with excellent adhesiveness and hydrolyzability can be manufactured.

Patent applicant: Toshiba Chemical Corporation

Claims (1)

[Claims] 1. In a resin-sealed semiconductor device in which a semiconductor element is bonded onto a lead frame, a conductive paste containing (A) a high-purity resin, (B) a low-viscosity diluent, and (C) a silver-plated copper-based conductive powder is used. A resin-sealed semiconductor device characterized in that it is bonded by using a resin-sealed semiconductor device.