Electrically conductive adhesive sheet, circuit board and electrical ...

[54] ELECTRICALLY CONDUCTIVE ADHESIVE SHEET, CIRCUIT BOARD AND ELECTRICAL CONNECTION STRUCTURE USING THE SAME

[75] Inventors: Yoshio Fujiwara; Naotake Kobayashi;

Yuichi Matsubara; Hisashi Ando; Hidehiro Numao; Kazuaki Suzuki, all of Tochigi, Japan

[73] Assignee: Sony Corporation, Tokyo, Japan

[21] Appl. No.: 61,608

[22] Filed: Jun. 22,1987

Related U.S. Application Data

[63] Continuation of Ser. No. 686,457, Dec. 26, 1984, abandoned.

[30] Foreign Application Priority Data

Dec. 27, 1983 [JP] Japan 58-250788

Feb. 10, 1984 [JP] Japan 59-23882

Feb. 24, 1984 [JP] Japan 59-33793

[51] Int. CI.* B32B 15/00; B32B 3/00

[52] U.S. a 428/209; 428/356;

428/328; 428/901

[58] Field of Search 428/356, 328, 210, 209,

428/901

[56] References Cited

U.S. PATENT DOCUMENTS

3,740,366 6/1973 Sandeison et al 428/356 X

3,762,946 10/1973 Stow et al 428/356 X

3,778,306 12/1973 Stow 428/356 X

4,258,100 3/1981 Fujitani et al 428/356 X

4,546,037 10/1985 King 428/356 X

4,548,862 10/1985 Hartman 428/356 X

4,680,226 7/1987 Takeda 428/901 X

Primary Examiner—Nancy A. B. Swisher

Attorney, Agent, or Firm—Hill, Van Santen, Steadman &

Simpson

[57] ABSTRACT

An electrically conductive adhesive sheet is disclosed which has an electrically conducting property across a thickness thereof and an electrically insulating property along a sheet surface direction. The electrically conductive adhesive sheet comprises an electrically insulating adhesive material and electrically conductive metal powder uniformly dispersed therein. The metal powder has a melting point lower than a certain working temperature, and is flattened by application of pressure between a pair of conductors between which the adhesive sheet is provided. The adhesive material is molten at the certain working temperature and is flown by application of pressure. The adhesive sheet is useful to electrically connect a pair of circuit boards each having a plurality of conductor patterns thereon by bonding corresponding ones through the metal powder as molten, while keeping the neighboring patterns insulated. The circuit board is mechanically integrated simultaneously by the adhesive sheet. The circuit board and the connection structure using such an adhesive sheet as above are also disclosed.

16 Claims, 9 Drawing Sheets