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:
Dec. 09, 2003
Filed:
Oct. 09, 2001
Chi-Chuan Wu, Taichung, TW;
Abstract
A lead frame and a flip chip semiconductor package having the lead frame are proposed, in which a die pad of the lead frame is elevated with a height difference relative to leads of the lead frame, and the height difference cannot exceed the vertical height of a plurality of solder bumps, which electrically connect a semiconductor chip to the lead frame. In a reflow process, due to good wetability of the lead frame, the solder bumps keep collapsing, allowing the semiconductor chip placed above the die pad to gradually move downwardly until abutting the die pad, which then stops the chip from moving, so as to force the solder bumps to stop collapsing to be maintained with a certain height. This therefore helps eliminate the occurrence of over-collapsing of the solder bumps, and thus assure bonding quality between the solder bumps and the lead frame.