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:
Jan. 23, 2001
Filed:
Apr. 03, 1999
Joseph A. Benenati, Hopewell Junction, NY (US);
Claude L. Bertin, South Burlington, VT (US);
William T. Chen, Endicott, NY (US);
Thomas E. Dinan, San Jose, CA (US);
Wayne F. Ellis, Jericho, VT (US);
Wayne J. Howell, Wiliston, VT (US);
John U. Knickerbocker, Hopewell Junction, NY (US);
Mark V. Pierson, Binghamton, NY (US);
William R. Tonti, Essex Junction, VT (US);
Jerzy M. Zalesinski, Essex Junction, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
An integrated circuit assembly has pads of a chip electrically connected to pads of a substrate with rolling metal balls. A pliable material bonds the balls in movable contact with pads of the chip and substrate. Because the balls are relatively free to move, thermal expansion differences that would ordinarily cause enormous stresses in the attached joints of the prior art, simply cause rolling of the balls of the present invention, avoiding thermal stress altogether. Reliability of the connections is substantially improved as compared with C4 solder bumps, and chips can be safely directly mounted to such substrates as PC boards, despite substantial thermal mismatch.