JPS6077309A - Anisotropic conductive sheet and electric material using same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anisotropic conductive sheet and an electrical material using the same.

Thin sheets that are electrically insulated in the plane direction and conductive only in the thickness direction are called anisotropic conductive sheets, and are useful as electrical materials for electronic devices such as flexible printed wiring boards. A conductive sheet is used in which fibrous or acicular conductors are arranged in the thickness direction of a resin matrix sheet.

However, the above-mentioned conductive sheet is difficult to manufacture because the fibrous or acicular conductors must be aligned in length, arranged in the thickness direction of the sheet, and evenly dispersed, and can only be manufactured with a small area. However, it had the disadvantage of being expensive.

Furthermore, Mr. Kihatsu et al. has already reported that a sheet containing metal powder dispersed in a resin matrix has electrical anisotropy (Japanese Patent Publication No. 57-8675), but this is enough to be used for printed wiring boards, etc. It has been difficult to inexpensively produce a sheet having conductivity in the thickness direction.

In view of the above-mentioned drawbacks, the present invention has been made with the aim of easily and inexpensively obtaining a flexible anisotropic conductive sheet having electrical anisotropy and conductivity sufficient for use in printed wiring boards VK, and electrical materials using the same. As a result, it was discovered that it was sufficient to use a special copper powder as the metal powder, and the gist of this was that the reduction loss with the resin matrix was 0.1 to 18% by weight, and the average particle size was 15%. ~20
Consisting of μ dendritic electrolytic copper powder, the copper powder is 5 to 60% by volume.
an anisotropic conductive sheet having a surface resistance of 108 to 1016 Ω, a volume resistivity of 100 or less; One side of the anisotropic conductive sheet is made of 5-20μ dendritic electrolytic copper powder, the copper powder occupies 5-60% by volume, has a surface resistance of 10-10Ω, and a volume resistivity of 102Ω or less. It consists of an electrical material formed by stacking metal thin films.

The resin matrix used in the present invention h only needs to have film-forming ability and electrical insulation properties, and thermoplastic resins are preferably used. The thermoplastic resin is preferably one that has a strong binding force to copper powder, is in the form of a sheet or film KFIi, has high mechanical strength when shaped, is flexible and strong, such as polyethylene, polypropylene, polystyrene, cellulose acetate,
Polyvinyl butyral, polyvinyl acetal, polyvinyl chloride, polyflex, polyester, polyamide,
Photosensitive resins made by curing oligomers such as polyimide, polyimide amide, polycarbonate, flexible acrylate, acrylate, and acrylate of epoxy resin with ultraviolet rays can be mentioned. When used as a printed wiring board or connection material for equipment, it is often necessary to attach a hanger, so a material with excellent heat resistance is preferred, with a melting point of 182°C or higher being preferred, and more preferred. , a melting point of 250° C. or higher, and polyimide, polyamideimide, polycarbonate, polyester, cellulose acetate, and photosensitive resin are preferably used.

The copper powder used in the present invention is a dendritic electrolytic copper powder produced by electrolysis, and has a reduction loss of 111 to 0.
．． It is 8% heavy duty and has an average particle size of 5 to 20μ.

The above-mentioned reduction weight loss is the weight loss percentage measured when metal powder is heated in a stream of steam, and the weight loss percentage is calculated from this value.
The electrical resistance tends to vary, and on the other hand, if it becomes large, a large amount must be added to impart conductivity, making it difficult to color the sheet, so the reduction loss is o, 1 to α8%
limited to.

In addition, if the shape of the copper powder is other than dendritic, such as spherical, lumpy, scaly, flaky, etc., or if the average particle size is smaller than (L5μ), when the conductive sheet is made, Copper powder has a dendritic shape and has an average particle size of 0.0 μm, and has less anisotropy and an average particle size of 20 μm or more (this results in less electrical anisotropy and non-uniform conductivity). The average particle diameter Vi is preferably limited to .5 to 20μ, and is preferably from 1 to 10μ.

The anisotropic conductive sheet of the present invention is made of the resin matrix and electrolytic copper powder, which accounts for 5 to 60% by volume in the sheet, has a surface resistance of to' to 1016 Ω, and a volume resistivity of 102 Ω. The electrolytic copper powder is dispersed in the resin matrix as follows, and the electrolytic copper powder has 8 to 35 particles in the sheet. Any method may be adopted as the method for manufacturing the anisotropic conductive sheet of the present invention, such as Examples include solution casting method, emulsion casting method, calendar method, extrusion method, etc. Also, the military quality of the sheet is preferably 5 to 30μ, although it is not limited to special VC.

The second invention (hereinafter referred to as invention 2) is an electrical material that is formed by laminating a metal thin film on one side of the anisotropic conductive sheet.

Examples of the metal that forms the metal thin film include aluminum, silver, gold, copper, zinc, nickel, molybdenum, etc. Aluminum is preferably used, and any method can be used to form the metal thin film. For example, a vacuum evaporation method, an ion sputtering method, etc. may be mentioned, and a vacuum evaporation method is preferable.The thickness of the metal thin film is also not particularly limited, but it is preferably 40 to 5000 angstroms, and more preferably 200 angstroms. ~2000 angstroms.

The above electric material can be used as a 7-lexiple printed wiring board etc. by partially laminating metal thin films.

Note that since the metal thin film described above has low mechanical strength, it is practically undesirable to roughly stack the protective layer made of the resin matrix.

Since the anisotropic conductive sheet and structure for wood power are as described above, the sheet is electrically anisotropic, and when electricity is applied to one point on the sheet, the electricity is applied and the electricity is diffused in the plane direction. Since the other side of the sheet is energized without having to do so, a flexible sheet can be manufactured easily and at low cost.

Furthermore, since the second electrical material of the present invention has a metal thin film laminated on one side of the anisotropic conductive sheet, it is suitably used as an electrical material for flexible printed wiring boards and Connectaku MF electronic devices.

Next, the present invention will be explained with reference to examples.

Stream side 1 Cellulose acetate (average degree of polymerization 180) 100 parts Dendritic electrolytic copper powder 120 parts by weight (average particle size 2.5μ, reduction area 1lt 0.3%) Acetone 900 parts Ethanol 100 parts Above composition The mixture was dissolved and dispersed, cast onto a glass plate, and dried to obtain an anisotropic conductive sheet with a thickness of 15 μm. The electrolytic copper powder in the obtained sheet accounted for 15.3% by volume, and due to the surface resistance of the sheet, Experiments 1 and 2 were conducted in the same manner as in Example 1. In Experiment 1, a miniature light bulb was lit; In Experiment 2, it did not turn on.

Comparative Example 1 Urethane acrylic oligomer (manufactured by Nippon Gosei Kagaku Co., Ltd., trade name XP-4200B) 100 parts by weight 2 ethylhexyl acrylate 50 parts by weight 11 parts L6 hexane glycol diacrylate 50 parts by weight Curing agent (manufactured by Ciba Geigy Co., Ltd., Product name 1-184) 4-electrode surfactant (manufactured by Mallinckrodt, product name BYK300) 1-layer electrolytic copper powder (average particle size 30P1 reduction Wk 0.3%
) 205 parts by weight A sheet of grass grass 30P was obtained in the same manner as in Example 2 from the blend having the above composition. The electrolytic copper powder in the obtained sheet aged IL7 volume %, and the surface resistance of the sheet Ho,
5xto'Ω, and the volume resistivity is α5xio'Ω-
It was 6 in one.

Next, an aluminum vapor-deposited layer was laminated on the obtained sheet in the same manner as in Example 1, and experiment 1 was conducted in the same manner as in Example 1 using the obtained *@receipt, and the miniature light bulb turned on. I didn't.

In addition, a sheet with a thickness of 20 μm could not be created. Comparative Example 2 Cellulose acetate (average degree of polymerization 180) 100 parts by weight Dendritic electrolytic copper powder 120 pieces Average particle size 2. ．． 0μ, reducing solution 1to%) acetone 9
A sheet having a thickness of 15P was obtained in the same manner as in Example 1 from a blend consisting of 00 weights, weight tanol, 100 weights, and the above composition. The electrolytic copper powder in the obtained sheet occupied 15.3% by volume, and the surface resistance of the sheet was t
s x t o”Ω, and the volume resistivity is (15X
It was 10'Ω-1.

Next, an aluminum evaporator was laminated on the obtained sheet in the same manner as in Example 1, and experiment 1 was conducted in the same manner as in Example 1 using the obtained laminated sheet, and the miniature light bulb turned on. I didn't.

Comparative Example 3 Urethane acrylic oligomer (manufactured by Nippon Gosei Kagaku Co., Ltd., trade name manufactured by Co., Ltd., product name 1-184) Surfactant
1 weight 1 part (manufactured by Mallinckrodt, trade name: BYK30QC flaky crushed copper powder (average particle size t5μ, reducing liquid IQ, 4%) 23011
Part L: A sheet having a thickness of 20 μm was obtained in the same manner as in Example 2 from a blend having the above composition. The crushed copper powder in the obtained sheet accounts for 3% by volume of IL, and the surface resistance of the sheet is α5.
×100, and the volume resistivity is 0.8 × 10 Ω−1
Met.

Next, an aluminum evaporator was laminated on the obtained sheet in the same manner as in Example 1, and experiment 1 was conducted in the same manner as in Example 1 using the obtained laminated sheet, and the miniature light bulb turned on. No 1, Comparative Example 4 Urethane acrylic oligomer (manufactured by Nippon Gosei Kagaku Co., Ltd., trade name Manufactured by Chipa Geigy,
Product name 1-184) Quadruple It part surfactant (manufactured by Mallinckrodt, product name BYK300
) 1 weight, 1 part silver powder (average particle size 2, Op > 3QQIt intermittent) A sheet with a thickness of 20 μm was obtained in the same manner as in Example 2 from the blend consisting of the above composition. Silver powder in the obtained sheet. is 1
Occupies 4.3% by volume, and the surface resistance of the sheet is 0.3X10
'Ω, and the volume resistivity was on the 0.2×10”Ω- side. Experiment 2 was conducted in the same manner as in Example 1 using the obtained sheet, and the miniature light bulb lit up.

Next, an aluminum evaporator was laminated on the obtained sheet in the same manner as in Example 1, and the obtained laminated sheet was subjected to actual division in the same manner as in Example 1. The miniature light bulb was lit.

patent applicant Sekisui Chemical Co., Ltd. Representative: Mototoshi Fujinuma

Claims (1)

[Claims] L resin matrix and reduction loss are α1-(L8 double %
, made of dendritic electrolytic copper powder with an average particle size of 0.5~20μ, #copper powder accounting for 5~60% by volume, and a surface resistance of 108~
An anisotropic conductive sheet having a volume resistivity of 1016Ω and 102Ω-a or less. 2 Resin matrix and reduction weight loss a1~0.8% by weight
, consisting of dendritic electrolytic copper powder with an average particle size of 0.5 to 20p, the copper powder accounts for 5 to 60% by volume, and the surface resistance is 10' to
An electrical material comprising a metal wI film laminated on one side of an anisotropic conductive sheet having a volume resistivity of 1016Ω and 1010-1 or less. 3. The electrical material according to claim 2, item 11a, wherein the melting point of the resin matrix is 182°C or higher. 4. The electrical material according to claim 2 or 3, wherein the metal thin film is an aluminum vapor-deposited thin film.