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:
Apr. 22, 2014
Filed:
Jul. 13, 2011
Cheng-en Ho, New Taipei, TW;
Bo-zong Chen, Tainan, TW;
Chih-nan Chen, Taoyuan County, TW;
Yuan Ze University, Taoyuan County, TW;
Abstract
A method for controlling the beta-tin crystal orientation in solder joints is provided. The method is suitable for joining metallization pads using a solder containing tin and silver. By adjusting the silver content in the solder within a specific range of equal to or more than 2.5 wt. % and less than 3.2 wt. %, the [001] axes of beta-tin crystals in the solder is aligned to be in the direction parallel with a solder/metallization pad interface substantially. Electromigration-induced solder deformations and metallization pad consumption can be significantly reduced when solder joints have such a microstructure. Additionally, the undesired AgSn plates in the solder matrix can be avoided accordingly.