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:
Mar. 03, 1998
Filed:
Jun. 28, 1996
Yuichi Hamada, Gunma-ken, JP;
Meguru Kashida, Gunma-ken, JP;
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
Proposed is an improvement in a frame-supported pellicle, which is a device for dust-proof protection of a photomask used in the photolithographic patterning works in the manufacture of fine electronic devices, consisting of a rigid pellicle frame, a highly transparent membrane of a plastic resin spread over and adhesively bonded to one end surface of the pellicle frame in a slack-free fashion and a layer of a pressure-sensitive adhesive formed on the other end surface of the pellicle frame to facilitate mounting of the frame-supported pellicle on the surface of a photomask and to secure the same at the correct position. The improvement comprises forming the layer of the pressure-sensitive adhesive on the end surface of the pellicle frame to have an outwardly convex surface, for example, in the form of a barrel vault instead of the flat surface in the prior art so that the troubles in the prior art due to occurrence of air gaps between the surface of the adhesive layer and the surface of the photomask unavoidable in mounting of the conventional frame-supported pellicle can be prevented to ensure completely air-tight sealing thereby. The adverse influence on the pellicle membrane due to the air-tightness of sealing by the pressure difference between the outer and inner surfaces can be overcome by providing a penetrating opening for air escape in the pellicle frame covered with a filter sheet.