The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 06, 2002
Filed:
Feb. 24, 1999
Hideo Taguchi, Tokyo, JP;
Junichi Asada, Tokyo, JP;
Jun Omori, Tokyo, JP;
Toshikazu Mino, Tokyo, JP;
Naohisa Okumura, Tokyo, JP;
Hiroshi Shimoe, Tokyo, JP;
Toshitsune Iijima, Tokyo, JP;
Katsuhiko Oyama, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
An IC chip and overhang portions are stuck to tape by an adhesive agent layer having elasticity. A plurality of solder balls are attached to the tape. By soldering the solder balls to a printed board, a semiconductor device is mounted. In the case where a temperature cycle has been caused, thermal stress occurs between the IC chip and the printed board or between the hangover portion and the printed board because of a difference in coefficient of thermal expansion between the IC chip or the hangover portion and the printed board. However, this thermal stress is absorbed by the elasticity of the adhesive agent layer. As a result, little thermal stress is applied to solder balls. Even if the above described temperature cycle is repeated, therefore, the solder balls are electrically connected to the printed board stably over a long period of time. In addition, the area of the tape is widened by the area of the hangover portions. Accordingly, a larger number of solder balls can be attached to the tape without reducing the size of each of the solder balls.