JPH0669257A - Adhesive for semiconductor element and semiconductor device - Google Patents

Abstract

PURPOSE:To obtain adhesive which can adhere a semiconductor element to a support member at a low temperature in a short time without bleed from paste by incorporating special epoxy resin, curing agent, cure accelerator, special imidazole compound as additive therein. CONSTITUTION:The adhesive for a semiconductor element comprises mixed epoxy resin which is so prepared as to exhibit a liquid state at an ambient temperature by mixing epoxy resin which is liquid at the ambient temperature or epoxy resin which is solid or semisolid at the ambient temperature and liquid epoxy resin which can dissolve it, curing agent, cure accelerator, and imidazole compound represented by a general formula as shown as additive. A quantity of the additive is set to 0.001-0.01 equivalent with respect to one equivalent of the epoxy resin or the mixed epoxy resin. However, in the formula, R1 and R2 are hydrogen or the same or different alkyl group, and R3 is 11 or more C alkyl group. Further, the adhesive may comprise filler.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive for a semiconductor element and a semiconductor device, and more particularly to a highly reliable semiconductor which can shorten the process and cost and does not bleed out when the adhesive is cured. TECHNICAL FIELD The present invention relates to an adhesive for a semiconductor element capable of obtaining a device and a semiconductor device using the same.

[0002]

2. Description of the Related Art Conventionally, as a method of bonding a semiconductor element to a lead frame (support member) when manufacturing a semiconductor device, (1) a method of using an inorganic material such as gold-silicon eutectic as an adhesive, 2) There is a method in which silver powder or the like is dispersed in an organic material such as an epoxy resin type or a polyimide resin type to form a paste, and this is used as an adhesive. However, the former method has a high cost and is 350 to 40
Recently, high heat treatment of about 0 ° C is required, and the adhesive is hard and the chip is destroyed by thermal stress.
The latter method using a silver paste is predominant. In this method, generally, a silver paste is applied to a lead frame using a dispenser or a stamping machine, and then a semiconductor element is die-bonded and heat-cured to be bonded. As the method of heat curing, there are a batch method of curing in an oven and an in-line method of curing on a heated plate.

In the case of the former batch method, a long curing time of 150 to 180 ° C. for 1 to 2 hours for an epoxy resin paste and 180 to 300 ° C. for 1 to 2 hours for a polyimide resin paste is required. On the other hand, in the case of the latter in-line method, the curing time is as short as 30 to 120 seconds, but even the epoxy resin paste is 230 to 3
It is necessary to heat at a high temperature of 50 ° C. Therefore, the solvent or reactive diluent contained in the paste is volatilized in a short time and voids are likely to remain in the paste cured product, the adhesive strength is lowered, and the semiconductor element is floated, or the element is depleted by the volatile component. However, the surface of the semiconductor device is contaminated and the reliability of the semiconductor device is reduced. In addition, since the amount of the reactive diluent is reduced by using the liquid epoxy resin, the voids are reduced, but on the other hand, there is a drawback that resin bleeding easily occurs. In other words, this phenomenon means that when a paste using a liquid epoxy resin is applied to a semiconductor element support member (lead frame) and the semiconductor element is placed and cured, the resin in the paste causes the silver plated surface of the support member surface. It is a so-called bleed that oozes out. When bleeding occurs, the adhesion with the encapsulant is reduced at that part, and when the bleeding reaches the ground bonding part, wire bonding cannot be performed, or even if it can be bonded easily peels off. There was a drawback that it decreased.

[0004]

The present invention eliminates the above-mentioned drawbacks of the prior art and eliminates bleed from the paste,
The present invention provides an adhesive for a semiconductor element, which can bond a semiconductor element and a supporting member at low temperature in a short time, and a semiconductor device using the same.

[0005]

Means for Solving the Problems The present invention comprises (1) mixing an epoxy resin (a) which is liquid at room temperature or a solid or semi-solid epoxy resin at room temperature with a liquid epoxy resin capable of dissolving the epoxy resin at room temperature. A mixed epoxy resin (b), (2) a curing agent, which is adjusted to show a liquid state,
General formula (I) as (3) curing accelerator and (4) additive

[Chemical 2] (Wherein R ₁ and R ₂ represent hydrogen or the same or different alkyl groups, and R ₃ represents an alkyl group having 11 or more carbon atoms), and (4) the amount of the additive. 0.001 to 0.01 with respect to 1 equivalent of the epoxy resin (a) or the mixed epoxy resin (b).
The present invention relates to an equivalent semiconductor element adhesive and a semiconductor device obtained by joining a semiconductor element to a supporting member using the semiconductor element adhesive.

The liquid epoxy resin (a) used in the present invention at room temperature preferably has two or more epoxy groups in one molecule from the viewpoint of curability, but is not particularly limited. As such an epoxy resin, for example, an epoxy resin derived from bisphenol A, bisphenol F, bisphenol AD, etc. and epichlorohydrin, AER-X8501 (manufactured by Asahi Kasei Corporation),
YDF-170 (manufactured by Tohto Kasei Co., Ltd.), R-710 (manufactured by Mitsui Petrochemical Co., Ltd.), novolac type epoxy resin N-730S.
(Manufactured by Dainippon Ink and Chemicals, Inc.) and the like. These epoxy resins may be used in appropriate combination.

The solid or semi-solid epoxy resin (b) used in the present invention is not particularly limited, but it is a phenol novolac type epoxy resin, Ouatr.
ex-2010 (manufactured by Dow Chemical Co.), cresol novolac type epoxy resin YDCN-702 (manufactured by Toto Kasei Co., Ltd.), EOCN-100 (manufactured by Nippon Kayaku Co., Ltd.), bisphenol A type epoxy resin, R-301, YL-980.
(Made by Yuka Shell Epoxy Co., Ltd.), polyfunctional epoxy resin E
PPN-501 (manufactured by Nippon Kayaku Co., Ltd.), TACTIX-74
2 (manufactured by Dow Chemical Co.), VG-3101 (manufactured by Mitsui Petrochemical Co., Ltd.), 1032S (manufactured by Yuka Shell Epoxy Co., Ltd.), epoxy resin HP-40 having a naphthalene skeleton.
32 (manufactured by Dainippon Ink and Chemicals, Inc.), alicyclic epoxy resin
EHPE-3150 (manufactured by Daicel Chemical Industries, Ltd.) and the like, and these epoxy resins may be appropriately combined and used. These epoxy resins are mixed with a liquid epoxy resin capable of dissolving the epoxy resin, and are adjusted to be liquid at room temperature before use.

As the liquid epoxy resin which can dissolve the solid or semi-solid epoxy resin used in the present invention, the above-mentioned epoxy resin (a) can be used, and further phenyl glycidyl ether, cresyl glycidyl ether, Paratertiary butyl phenyl glycidyl ether, para-secondary phenyl glycidyl ether,
Amine type epoxy resin ELM-100 (Sumitomo Chemical Co., Ltd.)
It is also possible to use reactive diluents such as

The curing agent used in the present invention is not particularly limited, but for example, phenol resin, H-1 (trade name of Meiwa Kasei Co., Ltd.), phenol aralkyl resin, XL-2.
25 (trade name of Mitsui Toatsu Chemicals, Inc.), dicyandiamide,
SP-10 (product name manufactured by Nippon Carbide Co., Ltd.), dihydrazide dihydrochloride, ADH, PDH, SDH (product name manufactured by Nippon Hydrazine Industry Co., Ltd.), imidazoles, curezol (product name manufactured by Shikoku Kasei), microcapsule type curing agent, Novacure (a product name of Asahi Kasei Kogyo Co., Ltd.) and the like can be mentioned. Further, as the curing accelerator, EMZ.K, TPP. Organic boron salts such as K (trade name of Hokuko Kagaku), tertiary amines and salts thereof, DBU, U-CAT 102, 106, 83
Examples thereof include tertiary amines such as 0, 340, and 5002 (trade name manufactured by San-Apro) and salts thereof, and imidazoles such as Cuazole (trade name manufactured by Shikoku Kasei). These curing agents and curing accelerators may be used alone, or several kinds of curing agents and curing accelerators may be appropriately combined and used.

Examples of the additive represented by the general formula (I) of the present invention include 2-undecylimidazole and 2-heptadecylimidazole. The alkyl group represented by R ₁ and R _{2 in} the general formula (I) is preferably an alkyl group having 1 to 2 carbon atoms. R ₃ is preferably an alkyl group having 17 or less carbon atoms. The amount used is 0.001 to 0.01 equivalent to 1 equivalent of the epoxy resin, and preferably 0.001 to 0.005 equivalent from the storage stability. 0.0
If it is less than 01 equivalent, the bleeding control is poor. That is,
The imidazoles represented by the general formula (I) are known as curing agents or curing accelerators for epoxy resins,
In the present invention, the imidazole compound represented by the general formula (I) is not used as a curing agent or a curing accelerator. Further, when used as a curing accelerator, it is known to be used in 0.017 to 0.1 equivalent to 1 equivalent of the epoxy resin, but in the present invention, 0.001 to 0.01 equivalent.
It is used within the equivalent range and exhibits a remarkable effect as a bleeding inhibitor.

Examples of the silica powder which is the filler used in the present invention include ultrafine silica powder Aerosil RY.
-200 (Nippon Aerosil), Crystallite 5X
-X (manufactured by Tatsumori Co., Ltd.) and the like, and the silver powder is not limited in particle size, shape, etc., and has a flake shape, a dendritic shape,
Spherical or amorphous silver powder can be used, and examples thereof include Silvest TCG-1 (manufactured by Tokuriki Kagaku Kenkyusho Co., Ltd.) and Silflake Agc-A (manufactured by Fukuda Metal Foil & Powder Industry Co., Ltd.).

The adhesive according to the present invention can be added with a diluent, if necessary, in order to improve workability at the time of preparation and coating workability at the time of use. As these diluents, butyl cellosolve, carbitol, butyl cellosolve acetate, carbitol acetate, ethylene glycol diethyl ether, relatively high boiling organic solvents such as α-terpineol, PGE (Nippon Kayaku Co., Ltd.), P
P-101 (manufactured by Tohto Kasei Co., Ltd.), ED-502, 503
(Manufactured by Asahi Denka Co., Ltd.), YED-122 (manufactured by Yuka Shell Epoxy Co., Ltd.), KBM-403, LS-7970 (manufactured by Shin-Etsu Chemical Co., Ltd.), TSL-8350, TSL-8355, TS.
Diluents having 1-2 epoxy groups in one molecule such as L-9905 (manufactured by Toshiba Silicone Co., Ltd.) and the like can be mentioned.
The adhesive according to the present invention further includes a silane coupling agent, an adhesive strength improving agent such as a titanium coupling agent, if necessary,
A nonionic surfactant, a wetting improver such as a fluorosurfactant, a defoaming agent such as silicone oil, and the like can be appropriately added.

The adhesive for semiconductor devices according to the present invention is prepared by, for example, dissolving and mixing a solution prepared by dissolving the liquid epoxy resin or the solid epoxy resin in the liquid epoxy resin or the diluent at a temperature of 80 to 120 ° C. in a flask. A varnish is prepared by mixing the varnish with a curing agent, a curing accelerator, and an additive represented by the general formula (I) using, for example, a three-roll mill, a planetary mixer, a raker, a ball mill or the like.

In the semiconductor device using the adhesive according to the present invention, the adhesive of the present invention is applied to a supporting member such as a lead frame by a dispensing method using an injection cylinder, a stamping method, a screen printing method, etc. The element is pressure-bonded and then heated and hardened by using a heating device such as a hot-air circulation type dryer or a heat block to bond the semiconductor element to the support member, and thereafter, the wire bonding step and the sealing step are performed to manufacture the semiconductor element.

[0015]

EXAMPLES The present invention will be described below with reference to examples. Example 1 YDF-170 (bisphenol F type epoxy resin, epoxy equivalent 170, Toto Kasei product name) 24 parts by weight (0.15 equivalent), dicyandiamide 0.181 parts by weight, 2-phenyl-4-methyl-5- 1.222 parts by weight of hydroxymethyl imidazole (hereinafter abbreviated as 2P4MHZ), 0.5 parts by weight of HX-3742 (microcapsule type modified imidazole, trade name of Asahi Kasei), 0.398 parts by weight of 2-heptadecyl imidazole (epoxy resin 1) 0.0087 equivalents relative to equivalents) were uniformly mixed with a three-roll to obtain an adhesive. Table 1 shows the evaluation results of this property.

Example 2 0.6 part by weight of RY-200 (silica powder, trade name of Nippon Aerosil) was added to the formulation of Example 1 to obtain an adhesive in the same manner as in Example 1. Table 1 shows the evaluation results of this property.

Example 3 RY-200 of Example 2 was used as silver powder silflake Agc-A.
An adhesive was obtained in the same manner as in Example 2, except that 56 parts by weight of Fukuda Metal Foil Powder (trade name) was used. Table 1 shows the evaluation results of this property.

Example 4 An adhesive was obtained in the same manner as in Example 2, except that 0.289 parts by weight (0.0087 equivalents) of 2-undecylimidazole was used instead of 2-heptadecylimidazole of Example 2. Table 1 shows the evaluation results of this property.

Example 5 Quatrex-201 was added to 10 parts by weight of YDF-170.
Add 0.4 parts by weight (trade name of Dow Chemical Co., epoxy equivalent 180) and 10 parts by weight of N-730 (trade name of Dainippon Ink and epoxy equivalent 180), heat to 100 ° C. and stir for 1 hour. A liquid mixed epoxy resin was obtained. After cooling this to 23 to 25 ° C., dicyandiamide, 2P4MHZ, HX-3742, 2-heptadecylimidazole and Agc-A were mixed by a triple roll at a compounding ratio shown in Table 1 to obtain an adhesive. Table 1 shows the evaluation results of this property.

Example 6 The amount of 2-heptadecylimidazole of Example 3 was adjusted to 0.0
An adhesive was obtained in the same manner as in Example 3 except that the amount was changed to 5 parts by weight (0.0011 equivalent). Table 1 shows the evaluation results of this property.

Example 7 The amount of 2-heptadecyl imidazole of Example 3 was 0.2.
An adhesive was obtained in the same manner as in Example 3 except that the amount was changed to 3 parts by weight (0.005 equivalent). Table 1 shows the evaluation results of this property.

Comparative Example 1 The amount of 2-heptadecyl imidazole of Example 3 was 0.0
An adhesive was obtained in the same manner as in Example 3 except that the amount was changed to 25 parts by weight (0.0005 equivalent). Table 1 shows the evaluation results of this property.

Comparative Example 2 The amount of 2-heptadecyl imidazole of Example 3 was 1.0.
An adhesive was obtained in the same manner as in Example 3 except that the amount was changed to parts by weight (0.022 equivalent). Table 1 shows the evaluation results of this property.

Comparative Example 3 The 2-heptadecyl imidazole of Example 3 was added to 2E4MZ.
An adhesive was obtained in the same manner as in Example 3 except that 0.3 part by weight of -CN (1-cyanoethyl-2-ethyl-4-methylimidazole, trade name manufactured by Shikoku Kasei) was changed. Table 1 shows the evaluation results of this property.

Comparative Example 4 The 2-heptadecyl imidazole of Example 3 was mixed with 2MZ-C.
An adhesive was obtained in the same manner as in Example 3, except that the amount of N (1-cyanoethyl-2-methylimidazole, trade name of Shikoku Kasei Co., Ltd.) was changed to 0.3 part by weight. Table 1 shows the evaluation results of this property.

Comparative Example 5 An adhesive was obtained in the same manner as in Example 3 except that 2-heptadecylimidazole in Example 3 was excluded. Table 1 shows the evaluation results of this property.

Comparative Example 6 10 parts by weight of para-secondary phenyl glycidyl ether (ELD-230, trade name of Sumitomo Chemical Co., Ltd.) was added to 16 parts by weight of phenol novolac resin H-1 (trade name of Meiwa Kasei Co., Ltd.), and the mixture was heated to 100 ° C. After heating and stirring for 1 hour and cooling, 24 parts by weight of YDF-170 and 1.2 parts by weight (0.026 equivalents) of 2-heptadecylimidazole Agc-
A 119 parts by weight of A was uniformly mixed with a three-roll mill to obtain an adhesive. Table 1 shows the evaluation results of this property.

Evaluation Method of Characteristics (1) Viscosity The viscosity (Pa · s) at 25 ° C. was measured using an EHD type viscometer (manufactured by Tokyo Keiki). (2) Gelation time According to JIS C 2104, the gelation time at 120 ° C was measured. (3) Bleed After applying the adhesive to the silver plated part of the lead frame,
The adhesive was cured on a heat block heated to ° C, and the presence or absence of bleeding was observed with a stereoscopic microscope (magnification: 30 times). ○ indicates that bleeding (bleeding out of the resin component from the cured area) did not occur, and × indicates that bleeding occurred. (4) Storage stability After leaving the adhesive in an atmosphere of 25 ° C for 3 days, the initial viscosity Was measured.

[0029]

[Table 1]

As can be seen from Table 1 and the figures, in the comparative example, bleeding of the resin occurs around the applied adhesive, and depending on the amount of application, it spreads over the entire surface of the supporting member, and the adhesion to the sealing material, or However, according to the adhesive of the present invention, bleeding does not occur at all, as shown in Table 1 and FIG.

[0031]

The adhesive for semiconductor elements according to the present invention can suppress the bleeding of resin when the adhesive is cured by the bleeding suppressing effect of the additive, and this adhesive can be used for die bonding of semiconductor devices. When used as an agent, the reliability of the bonding of the ground bonding wire can be improved, and the adhesiveness between the supporting member and the encapsulant does not decrease, so the reliability as a semiconductor device can be improved. .

Claims (5)

[Claims] (1) An epoxy resin (a) which is liquid at room temperature or a solid or semi-solid epoxy resin at room temperature and a liquid epoxy resin which can dissolve the epoxy resin are mixed and adjusted so as to be liquid at room temperature. The mixed epoxy resin (b), the curing agent (2), the curing accelerator (3) and the additive (4) represented by the general formula (I): (Wherein R ₁ and R ₂ represent hydrogen or the same or different alkyl groups, and R ₃ represents an alkyl group having 11 or more carbon atoms), and (4) the amount of the additive. 0.001 to 0.01 with respect to 1 equivalent of the epoxy resin (a) or the mixed epoxy resin (b).
Adhesive for semiconductor devices that is equivalent. 2. The adhesive for a semiconductor element according to claim 1, which further contains a filler. 3. The filler is silica powder.
An adhesive for a semiconductor device as described above. 4. The adhesive for a semiconductor device according to claim 2, wherein the filler is silver powder. 5. A semiconductor device obtained by bonding a semiconductor element to a supporting member using the adhesive for semiconductor elements according to claim 1.