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:
May. 03, 2016
Filed:
Feb. 09, 2012
Applicants:
Neal Wood, Worcestershire, GB;
Dirk Tews, Berlin, DE;
Assignee:
Atotech Deutschland GmbH, Berlin, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C23G 1/02 (2006.01); H05K 3/26 (2006.01); C23F 1/40 (2006.01); H01L 21/321 (2006.01); H01L 21/3213 (2006.01); H05K 3/34 (2006.01); H01L 21/768 (2006.01);
U.S. Cl.
CPC ...
H05K 3/26 (2013.01); C23F 1/40 (2013.01); H01L 21/32115 (2013.01); H01L 21/32134 (2013.01); H05K 3/3473 (2013.01); H01L 21/7684 (2013.01); H05K 2203/054 (2013.01); H05K 2203/0793 (2013.01);
Abstract
A process for etching excess tin or tin alloy deposits including the steps of providing a substrate having recessed structures filled with tin or a tin alloy and an excess layer of tin or tin alloy, providing an aqueous etching solution consisting of a source of hydroxide ions and a nitro-substituted aromatic sulfonic acid and having a pH value greater than 7, and contacting said substrate with said aqueous etching solution for removing said excess tin or tin alloy layer on top of the recessed structures filled with tin or a tin alloy.