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:
Sep. 13, 1994
Filed:
Sep. 27, 1993
Industrial Technology Institute, Chutung, TW;
Abstract
A wet etching process for forming vias or pre-designed patterns in organic polymeric layers such as fully or substantially fully cured polyimide layers which are used as circuit carriers in laminated integrated circuits by placing said organic polymeric layer in an etching bath containing two electrodes immersed in an etching solution and applying an alternating current having a voltage of about 0.3 to 1.0 volt and a frequency of about 60 Hz, or a direct current of about 0.8 to 20 volt to the electrodes. The etching solution contains acid or metallic hydroxide and, optionally, 3-15 wt % N-methyl-2-pyrrolidone. The present invention provides a fast and safe etching technique without the need to use the toxic and explosive etching chemicals such as hydrazine hydrate or ethylene diamine.