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. 24, 2001
Filed:
Jan. 08, 1999
Solomon I. Beilin, San Carlos, CA (US);
William T. Chou, Cupertino, CA (US);
David Dung Ngo, San Jose, CA (US);
Fujitsu Limited, , JP;
Abstract
Methods of etching polyamic acid layers and the like are disclosed. In exemplary embodiments of the present invention, the polymeric acid layer to be etched is alternatively exposed to etchant solutions (etchants) and rinse solutions, where the etchant solutions are of relatively moderate alkalinity and the rinse solutions have a lower pH than the etchant solutions. The present invention enables polymeric acid layers to be developed with standard basic etchants at relatively moderate concentrations and at room temperature with little, if any, corrosion to any underlying metal layers. The present invention enables the more reliable and cleaner spin-spray processing method to be employed, thereby significantly increasing yields and reducing overall processing costs. The present invention also enables the etching of thick layers of polymeric acid without the need for special treatments, such as exposure to highly concentrated etchant solutions or high temperature processing conditions.