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:
Jun. 22, 1993
Filed:
Mar. 25, 1992
Jacques Leibovitz, San Jose, CA (US);
Daniel J Miller, San Francisco, CA (US);
Maria L Cobarruviaz, Cupertino, CA (US);
John P Scalia, San Jose, CA (US);
Howard H Nakano, Corvallis, OR (US);
Voddarahalli K Nagesh, Cupertino, CA (US);
Clinton C Chao, Redwood City, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A specialized etching method for producing fine-geometry gold circuit structures. Production thereof is accomplished by maintaining a constant gold etching rate. Metal etching normally slows as the amount of dissolved gold (a reaction product of the etching process) increases. To remove the dissolved gold, one method involves cooling the etchant to precipitate a gold complex therefrom. The remaining, recovered etchant is then heated and made available for continued etching. Another method involves a cathode/anode assembly which is immersed in the etchant. Activation of the assembly recovers metallic gold and regenerates the etchant. These methods, when used continuously or periodically in a dip or spray etching system, maintain a constant etching rate. As a result, fine-geometry circuit structures may be accurately produced while minimizing material costs (e.g. etchant use) and minimizing the production of undesirable waste products and disposal expenses associated therewith.