JPH0793330B2 - Semiconductor element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a semiconductor element such as a large IC in which a chip is sealed with a resin, and particularly to moisture resistance, hydrolysis resistance and adhesiveness. It relates to an excellent semiconductor device.

(Prior Art) The process of connecting a semiconductor chip such as an IC or LSI to a predetermined portion on a thin metal plate (lead frame) is one of the important processes that affect the long-term reliability of the device. In the past, the Au-Si eutectic method, in which the silicon surface of the chip was thermocompression bonded to the gold-plated surface on the lead frame, was the mainstream connection method. However, in recent years, with the rise of precious metals, especially gold, in resin-sealed semiconductor devices, Au-Si eutectic method
The method of using solder, the method of using a conductive adhesive, etc. are rapidly shifting.

However, although the method using solder has been partially put into practical use, it has been pointed out that solder or solder balls scatter and adhere to electrodes or the like, which causes corrosion breakage. On the other hand, in the method using a conductive adhesive, an epoxy resin mixed with silver powder is usually used, and it has been partially put into practical use for several decades, but in terms of reliability, the Au-Si eutectic We were not able to obtain satisfactory results in comparison with the law. When using a conductive adhesive, it has advantages such as superior heat resistance compared to the solder method, but on the other hand, since the resin and curing agent are not made for bonding semiconductor elements, voids Generation, moisture resistance,
Inferior in hydrolysis resistance, it promotes corrosion of aluminum electrodes and often causes disconnection failure.
It was inferior to the Au-Si eutectic method. In recent years, IC / LSI and
With the increase in the size of semiconductor chips such as LEDs, chip cracks have occurred and the adhesive strength has decreased, which has become a problem.

(Problems to be Solved by the Invention) The present invention has been made in view of the above circumstances and drawbacks.
It is an object of the present invention to provide a highly reliable semiconductor element which is excellent in moisture resistance, hydrolysis resistance and adhesiveness corresponding to an increase in size of a semiconductor chip, and in particular has reduced warpage of the adhesive chip.

[Structure of the Invention] (Means and Actions for Solving Problems) As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that by using a resin composition described below,
The inventors have found that a highly reliable semiconductor element which is excellent in moisture resistance, hydrolysis resistance, and adhesiveness, does not generate voids, and has less chip warpage, and has completed the present invention. That is, the present invention provides (A) a solid epoxy resin, (B) a low-viscosity liquid epoxy resin, (C) a resin having a norbornene ring, (D) a polybutadiene liquid resin having an acrylonitrile group, (E) an imidazole catalyst, and (F) a conductive material. A semiconductor element characterized in that a semiconductor chip and a lead frame are bonded and fixed to each other using a resin composition containing a conductive powder.

The solid epoxy resin (A) used in the present invention is industrially produced and can be effectively used in the present invention, for example, the following bisphenol diepoxides. Shell Chemical Co. Epicoat 1001,1002,100
4,1007,1009, DER660,661,662,667,66 made by Dow Chemical Company
8,669, Ciba Geigy Araldite GY6071,6084,609
7,6099, Dainippon Ink and Chemicals, Inc. Epicron 1010,301
0 and Asahi Denka EP series EP-5100,5400,5700,5900
(All of the above are trade names) etc. Furthermore, as a solid epoxy resin, for example, by using a novolac epoxy resin having an average number of epoxy groups of 3 or more, it is possible to reduce the heat (350
It is possible to further improve the adhesive strength at (° C.), and as this novolac epoxy resin, one having a molecular weight of 500 or more is suitable. Examples of industrially manufactured novolac epoxy resins include the following. Ciba Geigy Araldite EPN1138,113
9, ECN1273,1280,1299, DEN431,438 made by Dow Chemical Co.,
Shell Chemical Co., Ltd. Epicoat 152,154, Union Carbide Co. ERR-0100, ERRB-0447, ERLB-0488, Nippon Kayaku Co., Ltd. EOCN series, Sanyo Kokusaku Pulp Co., Ltd. DER400 (all above are trade names), etc. These are used alone or as a mixed system of two or more kinds.

Examples of the low viscosity liquid epoxy resin (B) used in the present invention include β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane. And other silane monomers and bisphenol type low-viscosity liquid epoxy resins, alicyclic low-viscosity liquid epoxy resins, glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, and the like. These are used alone or in combination of two or more. .

The solid epoxy resin (A) and the low viscosity liquid epoxy resin (B) are blended in a weight ratio of 5:95 to 40:60. If the solid epoxy resin is less than 5% by weight, the required adhesive strength cannot be obtained, and if it exceeds 40% by weight, the workability of the conductive paste becomes extremely poor, which is not preferable.

The resin having a norbornene ring (C) used in the present invention includes a petroleum resin and the like, which is a general-purpose resin obtained from a C _{5 to} C ₉ fraction of petroleum. For example, as a commercially available product, Celoxide 4000 (trade name, manufactured by Daicel Chemical Co., Ltd.),
Tacky Roll 1000 (manufactured by Sumitomo Chemical Co., Ltd., trade name), Quinton 1500, 1000, 1300, 1700 (manufactured by Nippon Zeon Co., Ltd., trade name) and the like. And these are used individually or in mixture of 2 or more types. The proportion of the resin having a norbornene ring is preferably 0.5 to 30% by weight based on the total amount of the above-mentioned (A) solid epoxy resin and (B) low-viscosity liquid epoxy resin. When the compounding amount is 0.5% by weight at the end, there is no effect in improving the adhesive strength, and when it exceeds 30% by weight, the reactivity tends to be poor, which is not preferable.

Examples of the (A) acrylonitrile group-containing polybutadiene liquid resin used in the present invention include CTBN1300 and 2000.
(Manufactured by Ube Industries, Ltd.) and the like, and one kind or a mixture of two or more kinds is used. The mixing ratio of the polybutadiene liquid resin is preferably 0.5 to 30% by weight based on the total amount of the (A) solid epoxy resin and the (B) low viscosity liquid epoxy resin. If the blending amount is less than 0.5% by weight, there is no effect on low stress, and if the blending amount exceeds 30% by weight, the adhesive force tends to decrease, which is not preferable.

Examples of the (E) imidazole catalyst used in the present invention include 2PZ-OK, 2PZ-CN, 2MZ-OK (all of which are trade names) manufactured by Shikoku Chemicals. The imidazole-based catalyst is
Usually, 0.01 to 8% by weight is blended with respect to the total amount of (A) solid epoxy resin and (B) low-viscosity liquid epoxy resin.

(A) solid epoxy resin used in the present invention, (B) low viscosity liquid epoxy resin, (C) resin having norbornene ring,
When (D) a polybutadiene-based liquid resin having an acrylonitrile group and (E) an imidazole-based catalyst are blended, a solvent may be added to all components and mixed and dissolved, but first, a resin having a norbonene ring and an acrylonitrile group are first added. It is desirable to dissolve the polybutadiene-based liquid resin that is contained in a solvent and then add and mix a mixture of the solid epoxy resin and the low-viscosity liquid epoxy resin. Examples of the viscosity adjusting solvent used here include dioxane, hexanone, benzene, toluene, solvent naphtha, industrial gasoline, cellosolve acetate, ethyl cellosolve, butyl cellosolve acetate, butyl carbitol acetate, dimethylformamide, dimethylacetamide, N-methyl. Examples thereof include pyrrolidone, and these can be used alone or in combination of two or more.

As the conductive powder (F) used in the present invention, for example, silver powder or the like is used.

The resin composition used in the present invention contains a solid epoxy resin, a low-viscosity liquid epoxy resin, a resin having a norbornene ring, a liquid polybutadiene resin having an acrylonitrile group, an imidazole-based catalyst, and a conductive powder. Agents, coupling agents and other additives can be added. Then, this resin composition can be produced by sufficiently mixing the respective raw material components according to a conventional method, further kneading with, for example, three rolls, and then defoaming under reduced pressure. After the semiconductor chip and the lead frame are bonded and fixed using the resin composition thus manufactured, wire bonding is performed, and then the semiconductor chip is manufactured by sealing with a resin. This semiconductor element has little warp deformation of a large chip even when a resin composition is heated and cured at 200 ° C., has an adhesive strength required for bonding a semiconductor chip, and a wire bonding strength of 4 to 5 g. It is possible to obtain a strength equal to or higher than the value.

(Examples) Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In the examples and comparative examples, "parts" means "parts by weight" unless otherwise specified.

Example 1 Solid epoxy resin EOCN103S (trade name, manufactured by Nippon Kayaku Co., Ltd.) 9.
6 parts, liquid epoxy resin EX201 (product name, manufactured by Nagase Kasei Co., Ltd.)
9.6 parts, resin Celoxide 4000 having norbornene ring
(Daicel Co., Ltd., trade name) 3.0 parts, polybutadiene-based resin CTBN1300 (Ube Industries, trade name) 3.0 parts and diethylene glycol diethyl ether 1.8 parts were mixed and dissolved to obtain a viscous brown resin. To 29 parts of this resin, 1.2 parts of 2PZ-OK (manufactured by Shikoku Kasei Kogyo Co., Ltd.) as a catalyst and silver powder
70 parts were mixed to prepare a resin composition A.

Example 2 EOCN103S (supra) 5.0 parts, EP1001 (Shell Chemical Co., trade name) 4.6 parts, EX201 (supra) 9.6 parts, Quinton 1700
(Nippon Zeon Co., Ltd., trade name) 3.0 parts and diethylene glycol diethyl ether 1.8 parts were mixed and dissolved to obtain a viscous brown resin. 2PZ-O as a catalyst was added to 29 parts of this resin.
A resin composition B was manufactured by mixing 1.2 parts of K (described above) and 70 parts of silver powder.

Example 3 DEC400 (manufactured by Sanyo Kokusaku Pulp Company, trade name) 9.6 parts, EX201
(Previously) 9.6 copies, Quinton 1700 (previously) 3.0 copies, CTBN13
3.0 parts of 00 (described above) and 1.8 parts of diethylene glycol diethyl ether were mixed and dissolved to obtain a viscous yellow resin. To 29 parts of this resin, 1.2 parts of 2PZ-OK (mentioned above) as a catalyst and 70 parts of silver powder were added and sufficiently mixed to produce a resin composition C.

Comparative Example A commercially available epoxy resin-based conductive adhesive D for solvent type semiconductors was obtained.

Using the resin compositions A, B, C and the conductive adhesive D obtained in Examples 1 to 3 and Comparative Example, a semiconductor chip and a lead frame were adhesively cured to produce a semiconductor element. These semiconductor devices were tested for adhesive strength, hydrolyzability, moisture resistance and chip warpage. The results are shown in Table 1, and in all cases, the remarkable effect of the present invention was recognized.

The adhesive strength was measured by sticking a 4 × 12 mm silicon chip on a 200 μm thick lead frame (copper-based) and using a push-pull gauge at each temperature. The hydrolyzable Cl ion was cured under the conditions for adhering to a semiconductor device, then pulverized into 100 mesh, and heated and extracted at 180 ° C. for 2 hours to measure the amount of Cl ion. Humidity resistance test is conducted at a temperature of 121 ° C and a pressure of 2 atm in water vapor (PCT) and a temperature of 1
A moisture resistance test (bias-PCT) was conducted on each semiconductor element by applying an applied voltage of 15 V DC in water vapor at 20 ° C. and a pressure of 2 atm for evaluation. The number of semiconductor devices used in this test is 60 each.
Table 1 shows the number of defects generated with the passage of time.
The evaluation method is that the open or leak current due to the corrosion of the aluminum electrode that constitutes the semiconductor element is 50% of the allowable value.
It was judged to be defective when it increased to 0% or more. The warp of the chip was measured by measuring the surface of the chip after curing with a surface roughness meter and indicated by the distance between the center of the chip and the end.

[Effects of the Invention] As is clear from the above description and Table 1, the semiconductor element of the present invention exhibits excellent moisture resistance and hydrolysis resistance by using the resin composition as an adhesive. As a result, there is no disconnection failure due to corrosion of the aluminum electrode,
It is possible to obtain a highly reliable product in which voids do not occur, the adhesive chip warps little, and the adhesiveness is excellent, especially when heated.

Claims (1)

[Claims] 1. (A) Solid epoxy resin (B) Low-viscosity liquid epoxy resin (C) Resin having norbornene ring (D) Acrylonitrile group-containing polybutadiene liquid resin (E) Imidazole catalyst and (F) Conductivity A semiconductor element comprising a resin composition containing powder, and a semiconductor chip and a lead frame bonded and fixed to each other.