Multi-layer flexible wiring board and its production method

Application Number  00128197 Application Date  2000.10.17
Publication Number  1312671 Publication Date  2001.09.12
Priority Information   1999/10/18 JP 294686/99  
Applicant(s) Name  Sony Chemical Corp.  
Inventor(s) Name  Kurita Hideyuki;Hishinuma Hiroyuki  
Patent Agency Code  72001 Patent Agent  wang zhongzhong
AbstractThe present invention is directed to perform ultrasonic bonding of element pieces in a flexible board ultrasonically to each other, without using bumps. A metal coating 26 is formed on a surface of a connection part 181 of metal wiring 28 of two element pieces 10 and 30 of a flexible board. The connection parts 181 are brought into contact with each other, and ultrasonic wave is applied to each connection part 181 by a vibrator 45. The metal coatings 26 are joined to each other, and a multilayer flexible wiring board 50 is obtained. Since no bump is used, a plating process for bump formation is not required, and there is no influence of unevenness on the height of the bump. It is desirable that a heat reversible resin film 33 be formed on a the surface of one element piece 30 of the flexible board, and that the element pieces of the flexible board be adhered to each other by an adhesive force of the resin film 33.