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Developing RISTON

IP.com Disclosure Number: IPCOM000090532D
Original Publication Date: 1969-May-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

O'Flaherty, JF: AUTHOR

Abstract

RISTON* is a nonliquid photoresist comprising a sandwich of MYLAR* film and polyethylene film with a predyed, presensitized photopolymer in the middle. Since it is nonliquid, it is free from such inherent defects as pinholes which occur when liquid photoresists are used. For the recommended way of developing this photoresist, i.e., by spraying with cold chlorothene, its production usage requires new spraying equipment. Further, the use of chlorothene requires a continuous fresh supply of clear solvent or separate distillation and cooling apparatus for recovering the used solvent.

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Developing RISTON

RISTON* is a nonliquid photoresist comprising a sandwich of MYLAR* film and polyethylene film with a predyed, presensitized photopolymer in the middle. Since it is nonliquid, it is free from such inherent defects as pinholes which occur when liquid photoresists are used. For the recommended way of developing this photoresist, i.e., by spraying with cold chlorothene, its production usage requires new spraying equipment. Further, the use of chlorothene requires a continuous fresh supply of clear solvent or separate distillation and cooling apparatus for recovering the used solvent.

It would be advantageous to use existing vapor degreasing equipment for the development of RISTON. However, vapor degreasing equipment cannot be used in the development of this photoresist when the usual solvents such as trichlorethylene are used, since both exposed and unexposed portions of such resist are removed.

This method permits the development of RISTON with conventional vapor degreasing apparatus. The method comprises the steps of introducing for one minute into a vapor degreaser having exposed RISTON in it, the vapor of azeothrope: trichlorotrifluorthane, 1, 1-dichloroethane, i.e., 113-DCE, a product of Union Carbide. Then a mixture of 113-DCE vapor and 113-DCE spray are introduced into the vapor degreaser for two minutes. Following this, the RISTON is subjected to xylene spray for ten seconds and ammonium persulfate dip for ten seconds to remove any residual...