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:
Feb. 04, 2014
Filed:
Feb. 21, 2011
Daesik Choi, Seoul, KR;
Joonyoung Choi, Kyoung-ki-do, KR;
Wonll Kwon, Seoul, KR;
STATS ChipPAC, Ltd., Singapore, SG;
Abstract
A semiconductor wafer has a contact pad. A first insulating layer is formed over the wafer. A second insulating layer is formed over the first insulating layer and contact pad. A portion of the second insulating layer is removed to expose the contact pad. A first UBM layer is formed over and follows a contour of the second insulating layer and contact pad to create a well over the contact pad. A first buffer layer is formed in the well over the first UBM layer and the contact pad. A second UBM layer is formed over the first UBM layer and first buffer layer. A third UBM layer is formed over the second UBM layer. A bump is formed over the third UBM layer. The first buffer layer reduces stress on the bump and contact pad. A second buffer layer can be formed between the second and third UBM layers.