JP2000080340A - Electric insulating adhesive for electronic device and on-board device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric insulating adhesive for electronic devices which can be applied to a face-down assembly of electronic devices and has high cold-heat-cycle reliability and reliability after high temperature and humidity shelf test. SOLUTION: This adhesive contains, as the essential components, (A) a multifunctional epoxy resin having an epoxy equivalent of not more than 150, (B) an imidazole compound, (C) dicyandiamide and (D) a nonconductive inorganic filler. Its resin component contains 40-94 wt.% of the multifunctional epoxy resin, 3-40 wt.% of the imidazole compound and 1-10 wt.% of dicyandiamide. The adhesive contains 3-70 wt.% of the inorganic filler. The average particle sizes are not more than 5 μm for dicyandiamide and 0.1-3 μm for the inorganic filler.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrically insulating adhesive suitable for bonding an electronic device such as a semiconductor chip to a substrate in a face-down direction, and an electronic device mounted on the substrate using the same.

[0002]

2. Description of the Related Art In bonding conventional electronic devices, when an electronic device is bonded and electrically connected to a substrate of an electronic device in a face-down direction, the gap between the electronic device and the substrate other than the electrode portion is also underfilled. In many cases, it is filled with a resin composition such as a material or an anisotropic conductive material. These resin compositions are used for the purpose of protecting a circuit surface of an electronic device from an external environment and mechanically bonding the electronic device to a substrate.

[0003] With the recent technical improvement in the field of electronic equipment manufacturing, electronic devices tend to be larger and larger.
As electronic devices become smaller and lighter, flip-chip mounting for bonding electronic devices to a substrate in a face-down direction has been actively studied.

[0004]

However, in the conventional method of filling the gap between the electronic device and the substrate with an underfill material or an anisotropic conductive material or the like, the difference in the coefficient of linear expansion between the electronic device and the substrate causes the electronic device to have a problem. There is a shortage in the reliability of cooling and heating cycles when the size is increased.For example, at high and low temperatures, the expansion and contraction of the substrate due to heat is larger than that of the electronic device. There has been a problem that separation occurs between the object and the substrate, and conduction is also impaired.

In addition, there is a problem that the resin composition undergoes water absorption and expansion due to water absorption and moisture absorption, and peeling occurs between the resin composition and the electronic device or between the resin composition and the substrate, resulting in impaired conduction.

[0006] Therefore, there has been a demand for a highly reliable electrical insulating adhesive when an electronic device is bonded to a substrate in a face-down direction.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in adhesives for assembling electronic devices and the like. An object of the present invention is to provide an electrically insulating adhesive and a substrate mounted device having reliability of wet standing.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that the above problems can be solved by using a thermosetting resin composition described later. The present invention has been completed.

That is, the electrical insulating adhesive for an electronic device of the present invention comprises (A) a polyfunctional epoxy resin having an epoxy equivalent of 150 or less, (B) an imidazole compound, (C) dicyandiamide and (D) a nonconductive inorganic material. A substrate-mounted device comprising a filler as an essential component, and an electronic device adhered to a substrate using the adhesive.

Hereinafter, the present invention will be described in detail.

As the polyfunctional epoxy resin (A) used in the present invention, an epoxy resin having an epoxy equivalent of 150 or less is used. Specific examples include p-glycidylaminophenol-type epoxy [ELM-100 (trade name, manufactured by Sumitomo Chemical Co., Ltd.), Ep630 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.)
Trade name)], bisphenol F tetraglycidylamine type epoxy [Ep604 (trade name, manufactured by Yuka Shell Epoxy), tetraglycidyl-m-xylene diamine [TETRAD-X (trade name, manufactured by Mitsubishi Gas Chemical Co., Ltd.)], etc. Is mentioned. By using this polyfunctional epoxy resin, the crosslinked network after resin curing can be made denser, and the compounding ratio of the polyfunctional epoxy resin for this purpose is determined by the resin component [(D) non-conductive inorganic filler or the like. In the composition excluding the filler component, the same applies hereinafter). In addition, the polyfunctional epoxy resin may be used in combination with an epoxy resin conventionally used for an insulating paste, such as a bisphenol A type epoxy resin and a cycloaliphatic epoxy resin.

The imidazole compound (B) of the present invention includes 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole,
Examples thereof include 2-phenyl-4-methyl-5-hydroxymethylimidazole and the like, and those obtained by combining them with an acid such as hydroxybenzoic acid, phthalic acid, isocyanuric acid, cyanoethyl, triazine and the like can be used. These can be used alone or in combination of two or more.
The mixing ratio of the imidazole compound is 3 to 3 in the resin component.
It is desirable to use 40% by weight.

The dicyandiamide (C) used in the present invention is a catalyst and preferably has an average particle diameter of 5 μm or less for uniform dispersion. For example, DICY7 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.) can be mentioned. . By using this dicyandiamide, especially in the resin component, 3 to
By using dicyandiamide in the range of 20% by weight, the strength at the time of heating can be increased.

The non-conductive inorganic filler (D) used in the present invention includes oxides such as silica, alumina, zirconia and titania, nitrides such as silicon nitride and aluminum nitride, and compounds such as barium sulfate and calcium carbonate. And these can be used alone or in combination of two or more. (D) non-conductive inorganic filler,
It is contained in the adhesive at 33 to 70% by weight, and its average particle size is desirably 0.1 to 3 μm.

The adhesive for an electronic device according to the present invention comprises (A)
A polyfunctional epoxy resin; an imidazole compound of (B);
The dicyandiamide of (C) and the non-conductive inorganic filler of (D) are essential components. However, as long as the effects of the present invention are not impaired, and if necessary, other fillers, diluents, solvents,
Additives such as coupling agents and defoamers can be added.

A device mounted on a substrate can be obtained by bonding an electronic device to a substrate using the above-mentioned electrically insulating adhesive. As the substrate, an organic substrate such as an epoxy resin circuit substrate can be advantageously used.

[0017]

According to the electric insulating adhesive of the present invention, (A) a polyfunctional epoxy resin, (B) an imidazole compound,
The object was achieved by using (C) dicyandiamide and (D) a non-conductive inorganic filler as essential components, and by mixing them in a predetermined amount. In other words, even when a cycle of cooling and heating is applied to the electronic device and the substrate, and a force is repeatedly applied such that the electronic device side is concave at a high temperature and the electronic device side is convex at a low temperature, the adhesive for the electronic device is fixed, thereby reducing the warpage. Thus, high thermal cycle reliability can be obtained. Further, even in a high-temperature and high-humidity state, the adhesive absorbs and expands, so that the electronic device does not warp or the electrode portion of the electronic device is not peeled off from the substrate.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically with reference to examples.

Example 1 First, 100 parts by weight of silica (average particle size: 1.0 μm) and a methyltrimethoxysilane coupling agent TSL8113 were used.
2 parts by weight (trade name, manufactured by Toshiba Silicone Co., Ltd.) were mixed and stirred by a mixer, and then heat-treated at 200 ° C. for 1 hour in an oven to hydrophobize the silica surface. Next, an electric insulating adhesive was obtained by mixing and stirring the following components with a homogenizer.

(Composition) Glycidylamine type epoxy resin Epicoat 630 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.) 50 parts by weight, Bisphenol A type epoxy resin Epicoat 828 (brand name, manufactured by Yuka Shell Epoxy Co., Ltd.) 38 parts by weight, 7 parts by weight of 1,2-dimethylimidazole (trade name, manufactured by Shikoku Chemicals), 5 parts by weight of dicyandiamide (average particle diameter 0.7 μm), 100 parts by weight of surface-treated silica.

Example 2 First, 100 parts by weight of alumina (average particle size: 0.5 μm) and methyltrimethoxysilane coupling agent TSL811
2 parts by weight (trade name, manufactured by Toshiba Silicone Co., Ltd.) were mixed and stirred by a mixer, and then heat-treated in an oven at 200 ° C. for 1 hour to hydrophobize the alumina surface. Next, an electric insulating adhesive was obtained by mixing and stirring the following components with a homogenizer.

(Composition) Glycidylamine type epoxy resin Epicoat 630 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.) 50 parts by weight, Bisphenol A type epoxy resin Epicoat 828 (brand name, manufactured by Yuka Shell Epoxy Co., Ltd.) 38 parts by weight, 7 parts by weight of 1,2-dimethylimidazole (trade name, manufactured by Shikoku Chemicals), 5 parts by weight of dicyandiamide (average particle diameter 0.7 μm), 100 parts by weight of surface-treated alumina.

Comparative Example 1 As in Example 1, silica (average particle size: 1.0 μm) 10
0 parts by weight and methyltrimethoxysilane coupling agent T
2 parts by weight of SL8113 (trade name, manufactured by Toshiba Silicone Co., Ltd.) were mixed and stirred with a mixer, and then heated at 200 ° C. in an oven.
Heat treatment was performed for one hour to hydrophobize the silica surface. next,
The following composition was mixed and stirred with a homogenizer to obtain an electrically insulating adhesive of Comparative Example 1.

(Composition) Bisphenol A type epoxy resin Epicoat 828 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.) 88 parts by weight, 1,2-dimethylimidazole (trade name, manufactured by Shikoku Kasei Co., Ltd.) 7 parts by weight, dicyandiamide (average) 5 parts by weight, 100 parts by weight of surface-treated silica.

Comparative Example 2 As in Example 1, silica (average particle size: 1.0 μm) 10
0 parts by weight and methyltrimethoxysilane coupling agent T
2 parts by weight of SL8113 (trade name, manufactured by Toshiba Silicone Co., Ltd.) were mixed and stirred with a mixer, and then heated at 200 ° C. in an oven.
Heat treatment was performed for one hour to hydrophobize the silica surface. next,
The following composition was mixed and stirred with a homogenizer to obtain an electrically insulating adhesive of Comparative Example 2.

(Composition) 50 parts by weight of glycidylamine type epoxy resin Epicoat 630 (trade name, manufactured by Yuka Shell Epoxy) 43 parts by weight of bisphenol A type epoxy resin Epicoat 828 (brand name, manufactured by Yuka Shell Epoxy) 7 parts by weight of 1,2-dimethylimidazole (trade name, manufactured by Shikoku Chemicals), 100 parts by weight of surface-treated silica.

Comparative Example 3 As in Example 1, silica (average particle size: 1.0 μm) 10
0 parts by weight and methyltrimethoxysilane coupling agent T
2 parts by weight of SL8113 (trade name, manufactured by Toshiba Silicone Co., Ltd.) were mixed and stirred with a mixer, and then heated at 200 ° C. in an oven.
Heat treatment was performed for one hour to hydrophobize the silica surface. next,
The following composition was mixed and stirred with a homogenizer to obtain an electrically insulating adhesive of Comparative Example 3.

(Composition) 50 parts by weight of glycidylamine type epoxy resin Epicoat 630 (trade name, manufactured by Yuka Shell Epoxy Co.) 28 parts by weight of bisphenol A type epoxy resin Epicoat 828 (trade name, manufactured by Yuka Shell Epoxy Co.) 7 parts by weight of 1,2-dimethylimidazole (trade name, manufactured by Shikoku Chemicals), 5 parts by weight of dicyandiamide (average particle diameter 0.7 μm), 100 parts by weight of surface-treated silica.

Comparative Example 4 As in Example 1, silica (average particle size: 1.0 μm) 10
0 parts by weight and methyltrimethoxysilane coupling agent T
2 parts by weight of SL8113 (trade name, manufactured by Toshiba Silicone Co., Ltd.) were mixed and stirred with a mixer, and then heated at 200 ° C. in an oven.
Heat treatment was performed for one hour to hydrophobize the silica surface. next,
The following composition was mixed and stirred with a homogenizer to obtain an electrically insulating adhesive of Comparative Example 4.

(Composition) 50 parts by weight of glycidylamine type epoxy resin Epicoat 630 (trade name, manufactured by Yuka Shell Epoxy Co.), 38 parts by weight of bisphenol A type epoxy resin Epicoat 828 (trade name, manufactured by Yuka Shell Epoxy Co.) 7 parts by weight of 1,2-dimethylimidazole (trade name, manufactured by Shikoku Chemicals), 5 parts by weight of dicyandiamide (average particle diameter 0.7 μm), 100 parts by weight of surface-treated silica.

Comparative Example 5 The following composition was mixed and stirred with a homogenizer to obtain an electrically insulating adhesive of Comparative Example 5.

(Composition) Glycidylamine type epoxy resin Epicoat 630 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.) 50 parts by weight, Bisphenol A type epoxy resin Epicoat 828 (brand name, manufactured by Yuka Shell Epoxy Co., Ltd.) 38 parts by weight, 7 parts by weight of 1,2-dimethylimidazole (trade name, manufactured by Shikoku Chemicals), 5 parts by weight of dicyandiamide (average particle size 0.7 μm), and 100 parts by weight of untreated surface silica.

Next, board mounted devices were prepared using the electrically insulating adhesives of Examples 1 and 2 and Comparative Examples 1 to 5.

First, a test silicon chip electronic device having the following specifications was prepared.

(Specifications) Size 10 mm × 10 mm Thickness 0.3 mm Bump Gold-plated bumps and daisy chain bumps arranged around the periphery Bump size 80 μm × 80 μm × height 25 μm Bump interval 40 μm Number of bumps Total 312 bumps.

An organic substrate having the following specifications was prepared.

(Specifications) Substrate 0.8 mm thick FR-4 copper foil 18 μm thick Plating Au / Ni plating.

Approximately 7 mg of each electrically insulating adhesive was dispensed at the electronic device bonding position on the substrate. Thereafter, the electronic device is set at a predetermined position, and is bonded at 180 ° C. for 1 minute at a pressure of 20 ° C. using a bonding apparatus.
Connection was made with Kg to obtain a measurement sample.

The initial conduction of the electronic device of the sample thus obtained was measured. In addition, the same sample
Each cycle was stored in a cooling / heating cycle test tank at 0 ° C. and + 125 ° C. for 1000 cycles of 30 minutes, and thereafter the conduction was measured. Further, the sample was heated at 85 ° C. and 85% RH for 10 minutes.
After storing for 00 hours, the conduction was measured thereafter.

The measurement results of Examples 1 and 2 and Comparative Examples 1 to 5 are shown in Table 1.

[0041]

[Table 1] As is clear from Table 1, in Examples 1 and 2, the electrodes did not become OPEN even after the thermal cycle test, and the initial conduction was maintained. On the other hand, in Comparative Examples 1, 2, and 4, peeling occurred between the electronic device and the resin composition after the thermal cycle, and the electrical connection was broken. In Comparative Examples 2, 3, 4, and 5, conduction failure occurred after being left at high temperature and high humidity, and Comparative Examples 3 and 5 were in a disconnected state.

[0042]

According to the electric insulating adhesive of the present invention, when an electronic device such as a semiconductor chip is bonded to a substrate, a polyfunctional glycidylamine type epoxy resin, an imidazole compound, a dicyandiamide, a non-conductive inorganic filler can be used. In particular, by adding a predetermined amount of, it was possible to obtain high reliability in cooling and heating cycles and reliability after standing at high temperature and high humidity.

Claims (8)

[Claims] An electronic device comprising (A) a polyfunctional epoxy resin having an epoxy equivalent of 150 or less, (B) an imidazole compound, (C) dicyandiamide, and (D) a non-conductive inorganic filler as essential components. For electrically insulating adhesive. 2. The electrically insulating adhesive for electronic devices according to claim 1, wherein the polyfunctional epoxy resin (A) is contained in an amount of 40 to 94% by weight in a resin component excluding a filler component. 3. The electrically insulating adhesive for electronic devices according to claim 2, wherein the polyfunctional epoxy resin (A) is of a glycidylamine type. 4. The electrically insulating adhesive for electronic devices according to claim 1, wherein the imidazole compound (B) is contained in the resin component excluding the filler component in an amount of 3 to 40% by weight. 5. The electric insulating property for an electronic device according to claim 1, wherein (C) dicyandiamide is contained in the resin component excluding the filler component in an amount of 1 to 10% by weight and has an average particle size of 5 μm or less. adhesive. 6. The electronic device according to claim 1, wherein (D) the non-conductive inorganic filler is contained in the adhesive in an amount of 33 to 70% by weight and has an average particle size of 0.1 to 3 μm or less. Electrical insulating adhesive. 7. The surface of the (D) non-conductive inorganic filler,
7. A hydrophobizing treatment with a coupling agent.
An electrical insulating adhesive for an electronic device according to the above. 8. A device mounted on a substrate, wherein the electronic device is bonded to a substrate using the electrical insulating adhesive for electronic devices according to claim 1.