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:
Mar. 11, 2008
Filed:
Jun. 04, 2004
Feng-lung Chien, Taichung Hsien, TW;
Huang-chuan Chang, Taichung Hsien, TW;
Chun-sheng Ho, Taichung Hsien, TW;
Feng-Lung Chien, Taichung Hsien, TW;
Huang-Chuan Chang, Taichung Hsien, TW;
Chun-Sheng Ho, Taichung Hsien, TW;
Abstract
A process for forming a lead-free bump on an electronic component includes preparing the electronic component with at least one bond pad and a passivation layer formed thereon; forming an under bump metallurgy (UBM) structure on the passivation layer and the bond pad; applying a photoresist over the passivation layer, the photoresist having at least one opening corresponding to the bond pad; depositing a thick copper layer (about 1 to 10 μm thick) in the opening by electroplating; applying a copper-free or low-copper-content solder material on the copper layer; and performing a reflowing procedure under a suitable reflow temperature profile to allow copper ions to diffuse from the copper layer to the solder material so as to form the lead-free bump. This increases the copper content in the solder material but not raising the reflow temperature profile, thereby preventing deterioration of the photoresist due to over heat.