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:
Aug. 15, 1989
Filed:
Dec. 17, 1987
Applicant:
Inventors:
Edwin G Millis, Dallas, TX (US);
Samuel J Wood, Jr, Plano, TX (US);
Assignee:
Texas Instruments Incorporated, Dallas, TX (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ; G01J / ;
U.S. Cl.
CPC ...
250573 ; 250373 ; 356442 ; 354298 ;
Abstract
An optical analyzer and a developer recirculation system is used to determine the amount of photoresist polymer dissolved in a quantity of developer solution and the sensor output signal is utilized by a control computer to control the admission of fresh developer solution to replace used developer and maintain a fixed level of dissolved photoresist polymer to keep the developer bath at a fixed level of chemical activity.