JPH052915A - Semiconductor device - Google Patents

Abstract

PURPOSE:To improve such characteristics as anti-humidity, hydrolysis resistance, adhesive property and heat resistance by using bismaleimide induced from specific diamino-polysiloxane, specific 1, 2-polybutadiene epoxy compound and a conductive paste to fix adhesively a semiconductor chip to a lead frame. CONSTITUTION:Bismalemide induced from diaminopolysiloxane expressed by a formula I, 1,2-polybutadiene epoxy compound expressed by a formula II and a conductive paste are used to fix adhesively a semiconductor chip to a read frame. In the formulas, R<1> and R<2> represent two-valence hydrocarbon radicals, R<3> and R<4> represent one-valence hydrocarbon radicals, (n) represents an integer of 1-5. By this structure, such characteristics as anti-humidity, hydrolysis resistance, adhesive property, heat resistance become excellent, generation of void and erosion of an electrode are reduced and reliability is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device having excellent moisture resistance, hydrolysis resistance, adhesiveness, heat resistance and the like.

[0002]

2. Description of the Related Art ICs and Ls are mounted on a predetermined portion of a lead frame.
The process of connecting semiconductor chips such as SI is one of the important processes that affect the long-term reliability of the device. Conventionally, as this connection method, Au-S has been used in which the silicon surface of the semiconductor chip is pressure-bonded to the gold-plated surface on the lead frame.
The eutectic method was the mainstream. However, Au-S has been used in resin-encapsulated semiconductor devices triggered by the recent surge of precious metals, especially gold.
The eutectic method is rapidly changing to a method using solder, a method using a conductive paste, or the like.

However, although some methods using solder have been put to 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 paste, an epoxy resin mixed with silver powder is usually used, but in terms of reliability, satisfactory results were not obtained as compared with the Au-Si eutectic method. When using a conductive paste, although it has advantages such as excellent heat resistance as compared with the solder method, since the resin or curing agent is not intended for semiconductor element adhesion, the occurrence of voids, Inferior in moisture resistance and hydrolysis resistance,
In many cases, it promotes corrosion of the aluminum electrode and causes defective disconnection, and the reliability of the device was inferior to that of the Au-Si eutectic method. Further, with the increase in size of semiconductor chips such as IC, LSI, and LEDs, and the advent of various types of frames such as copper, chip cracks have occurred and adhesive strength has decreased, which has been a problem.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and is excellent in moisture resistance, hydrolysis resistance, adhesiveness, and heat resistance, and has voids and disconnection due to corrosion of aluminum electrodes. It is an object of the present invention to provide a highly reliable semiconductor device which has few defects and warpage and is compatible with the increase in size of semiconductor chips.

[0005]

As a result of earnest studies to achieve the above object, the present inventor has found that the above object can be achieved by a semiconductor device using a conductive paste having a composition described later. The present invention has been completed.

That is, the present invention provides (A) a bismaleimide derived from a diaminosiloxane represented by the general formula 3:

[0007]

[Chemical 3] (In the formula, R ¹ and R ² are divalent hydrocarbon groups, R ³ and R ⁴ are monovalent hydrocarbon groups, and R ¹ and R ² , R ³ and R 4
⁴ may be the same or different from each other, and n represents an integer of 1 to 5) (B) The epoxidized product of 1,2 polybutadiene represented by Structural Formula 4 and

[0008]

[Chemical 4] (C) A semiconductor device in which a semiconductor chip and a lead frame are bonded and fixed to each other using a conductive paste containing a conductive powder as an essential component.

The present invention will be described in detail below.

The conductive paste used in the present invention contains, as essential components, a bismaleimide derived from diaminosiloxane, an epoxidized product of 1,2-polybutadiene, and a conductive powder. These components will be described below.

The bismaleimide derived from the diaminosiloxane of the component (A) used in the present invention is a component that introduces an imide skeleton and a siloxane skeleton into a cured product, and condenses diaminosiloxane and maleic acid by a known method.
It can be easily produced by a dehydration cyclization reaction. As a typical example of such a diaminosiloxane,
And those shown in Chemical formula 6.

[0012]

[Chemical 5]

[0013]

[Chemical 6]

The epoxidized product of 1,2-polybutadiene (B) used for introducing a polybutadiene structure into the cured product of the present invention is a highly reactive oligomer containing an epoxy group and a vinyl group in the molecule, Its structure is estimated as

[0015]

[Chemical 7]

The epoxidized product is obtained by epoxidizing 1,2-polybutadiene by the hydrogen peroxide method, and specific compounds include BF-1000 (trade name, manufactured by Adeka Argus Chemical Co., Ltd.).

The above-mentioned bismaleimide (A) and (B)
The compounding ratio of the epoxidized product is preferably 50 to 95 parts by weight of the former and 5 to 50 parts by weight of the latter, more preferably 80 to 90 parts by weight of the latter and 10 to 20 parts by weight of the latter. To do.

Examples of the (C) conductive powder used in the present invention include silver powder, copper powder, nickel powder, powder having a metal layer on the surface, and the like. These may be used alone or in combination of two or more. You can The average particle diameter of each of these conductive powders is preferably 10 μm or less. If the average particle size exceeds 10 μm, the composition does not become a paste and the coating performance deteriorates, which is not preferable.

Conductive powder and resin component [(A) + (B)]
It is desirable that the blending ratio of and is 70/30 to 90/10 by weight. When the conductive powder is less than 70 parts by weight, satisfactory conductivity cannot be obtained, and when it exceeds 90 parts by weight, workability is deteriorated, which is not preferable.

After the above-mentioned components are sufficiently mixed, a kneading treatment is further performed with, for example, a three-roll mill, and then defoaming under reduced pressure can be performed to produce a conductive paste. The conductive paste used in the present invention may use an organic solvent as necessary for adjusting the viscosity. Examples of the organic solvent include dioxane, hexane, cellosolve acetate, ethyl cellosolve, butyl cellosolve, butyl cellosolve acetate, butyl carbitol acetate, and isophorone. These can be used alone or in combination of two or more. Further, this conductive paste is cured without using a curing agent, but an imidazole-based derivative, a maleation catalyst, or the like can also be used.

The conductive paste thus produced is filled in, for example, a syringe, and is discharged onto a lead frame using a dispenser to bond a semiconductor element, followed by wire bonding and sealing with a resin sealing material, The semiconductor device of the invention can be manufactured. Even when heated at 280 ° C (corresponding to the wire bonding temperature of the element), this semiconductor device has extremely small warpage deformation of the large chip, and the adhesive strength is the strength necessary for bonding the semiconductor chip, and it also absorbs little moisture. It was a thing.

[0022]

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

Example 1 A reaction vessel equipped with a stirrer, a thermometer and a Dean-Stark azeotropic distillation trap was charged with 100 parts of the diaminosiloxane shown in Chemical formula 8 and 80 parts of maleic anhydride, while nitrogen gas was being bubbled through. The temperature was raised. After reacting for 3 hours at a temperature of 100 ° C in the vessel, water produced by the xylol reflux method at 180 ° C was removed to the outside of the system. After reacting for 2 hours in this state, xylol was removed from the system by distillation under reduced pressure and cooled to synthesize a pale yellow bismaleimide derived from diaminosiloxane.

[0024]

[Chemical 8]

Epoxy compound BF-1000 (trade name, manufactured by Adeka Argus Chemical Co., Ltd.) is added to 85 parts of this bismaleimide.
A thermosetting resin composition was obtained by adding 15 parts and 0.1 part of an antioxidant and stirring well until uniform, and the components shown in Table 1 were added to this thermosetting resin composition with a three-roll mill. The conductive paste was manufactured by kneading once.

Next, using this conductive paste, a semiconductor chip and a lead frame were adhesively cured to manufacture a semiconductor device. These semiconductor devices were tested for adhesive strength, chip warpage, hydrolysis and moisture resistance. The results are shown in Table 2, and the remarkable effect of the present invention was recognized.

Example 2 100 parts of the diaminosiloxane shown in Chemical formula 9 was reacted with 70 parts of maleic anhydride in the same manner as in Example 1 to synthesize a pale yellow bismaleimide derived from diaminosiloxane.

[0028]

[Chemical 9]

To 85 parts of this bismaleimide, the epoxidized product BF-1000 (trade name, manufactured by Adeka Argus Chemical Co., Ltd.)
A thermosetting resin composition was obtained by adding 15 parts and 0.1 part of an antioxidant and stirring well until uniform, and the components shown in Table 1 were added to this thermosetting resin composition with a three-roll mill. The conductive paste was manufactured by kneading once.

Next, using this conductive paste, a semiconductor device was manufactured and tested in the same manner as in Example 1. The results are shown in Table 2.

Example 3 100 parts of the diaminosiloxane shown in Chemical formula 10 was reacted with 40 parts of maleic anhydride in the same manner as in Example 1 to synthesize a pale yellow bismaleimide derived from diaminosiloxane.

[0032]

[Chemical 10]

To 85 parts of this bismaleimide, the epoxidized product BF-1000 (trade name, manufactured by Adeka Argus Chemical Co., Ltd.)
A resin composition was prepared by adding 15 parts of antioxidant and 0.1 part of antioxidant and stirring well until uniform.

Next, using this conductive paste, a semiconductor device was manufactured and tested in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example A commercially available epoxy resin-based solvent-type conductive paste was obtained, and a semiconductor device was manufactured and tested in the same manner as in Example 1. The results are shown in Table 2.

The adhesive strength was measured by bonding a 4 × 12 mm silicon chip on a 200 μm thick lead frame and using a push-pull cage at a temperature of 350 ° C. 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 and the end of the chip. For the hydrolyzability, after curing under the conditions for bonding semiconductor elements, pulverize it to 100 mesh and
The amount of chlorine ions extracted by heating at 0 ° C. for 2 hours was measured by ion chromatography. Humidity resistance test,
(PCT) and temperature in water vapor at ℃ and pressure of 2 atm
A moisture resistance test (bias-PCT) was conducted for each semiconductor element by applying an applied voltage of 15 V in steam at 121 ° C. and a pressure of 2 atm for evaluation. The semiconductor devices used in this test are
Table 2 shows the number of defects with 60, which occurred over time.
The evaluation method was determined to be defective when the wire open or the leakage current increased to 500% or more of the allowable value due to the corrosion of the aluminum electrode constituting the semiconductor element.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

As is apparent from the above description and Table 2, the semiconductor device of the present invention is excellent in moisture resistance, hydrolysis resistance, adhesiveness, and heat resistance, and has a void and a disconnection due to corrosion of an aluminum electrode. It is a highly reliable semiconductor device that has few defects and warpage and is compatible with the increase in size of semiconductor chips.

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Claims (1)

Claims: (A) a bismaleimide derived from a diaminosiloxane represented by the general formula 1, (However, wherein R ¹ and R ² are divalent hydrocarbon radicals, R ³
And R ⁴ represents a monovalent hydrocarbon group, R ¹ and R ² , R ³
And R ⁴ may be the same or different from each other, and n is 1 to 5
(B) 1,2-polybutadiene epoxide represented by Structural Formula 2 and (C) A semiconductor device in which a semiconductor chip and a lead frame are bonded and fixed to each other by using a conductive paste containing a conductive powder as an essential component.