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. 31, 1999
Filed:
May. 20, 1998
Harold F Sandford, Groton, MA (US);
Anthony Zampini, Westborough, MA (US);
Shipley Company, L.L.C., Marlborough, MA (US);
Abstract
A method for converting a kinetically stable multiester of a naphthoquinone and an o-quinone diazide sulfonyl halide to a thermodynamically stable compound. The method comprises the steps of dissolving a phenol having at least two free phenolic hydroxyl groups and an o-naphthoquinone diazide sulfonyl halide in an aprotic solvent in the presence of a strong base, there being at least one mole of said naphthoquinone diazide sulfonyl halide per mole of phenol, reacting said phenol with said o-napthoquinone diazide sulfonyl halide until essentially of said o-naphthoquinone diazide sulfonyl halide is reacted with said polyhydroxy phenol, and following completion of said reaction, permitting the reaction product to remain in said solvent for a period of time of at least 15 minutes before recovering said photoactive compound The photoactive compound formed by the process is suitable for the formation of photoresists and is less apt to precipitate from solution during storage.