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:
Jul. 23, 1996
Filed:
Dec. 01, 1994
Tetsuo Aoyama, Niigata, JP;
Takeshi Nagasaka, Tokorozawa, JP;
Toshihiko Kobayashi, Tokorozawa, JP;
Naohito Yoshimura, Tokyo, JP;
Takashi Nakata, Tokyo, JP;
Youichi Takizawa, Tokyo, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
A developing solution comprising a specific amount of a quaternary ammonium hydroxide represented by the general formula [(R.sup.1).sub.3 N--R].sup.+ .multidot.OH.sup.- (R indicates an alkyl group having 1 to 3 carbon atoms or a hydroxy-substituted alkyl group having 1 to 3 carbon atoms, and R.sup.1 indicates an alkyl group having 1 to 3 carbon atoms) and, if necessary, a quaternary ammonium hydrogen carbonate represented by the general formula [(R.sup.1).sub.3 N--R].sup.+ .multidot.HCO.sub.3.sup.- (R and R.sup.1 are the same as the above) and having a pH in the range of 9 to 13, and a process for producing printed circuit boards using an organic alkali solution, are provided. The developing solution needs no defoaming agent because it causes little foaming. Printed circuit boards produced by using the developing solution have excellent finished accuracy. Therefore, fine circuits of printed circuit networks can be produced with stability.