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. 29, 1993
Filed:
Jul. 02, 1992
Toshimoto Nakagawa, Kawasakishi, JP;
Kouzo Tsukada, Yokohamashi, JP;
Shu Ogawa, Nagareyamashi, JP;
Shinichiro Shiotsu, Tatsunoshi, JP;
Hirama Rika Kenkyujio Ltd., both of, JP;
Nagase & Co., Ltd., both of, JP;
Abstract
An alkaline developing solution is used in development of photosensitive organic resin (photoresist) in liquid crystal board manufacturing process or printed board manufacturing process. The apparatus for controlling developing solution comprises developing solution discharge device for discharging developing solution by detecting the dissolved resin concentration in the developing solution by means of an absorption photometer (16), first replenishing device for replenishing undiluted developing solution and pure water by detecting the liquid level of the developing solution by means of a liquid level gauge (3), and second replenishing device for replenishing undiluted developing solution or pure water by detecting the alkali concentration of the developing solution by an electric conductivity meter (15). By thus constituting, the developing performance of the developing solution may be always kept constant, and the operation down time may be notably shortened.