Browse Prior Art Database

Bonded Degradable Mask

IP.com Disclosure Number: IPCOM000081317D
Original Publication Date: 1974-May-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Nufer, RW: AUTHOR [+2]

Abstract

A degradable mask on ceramic green sheets is used to apply metal paste, selectively to open channels and vias cut into the ceramic green sheet by a programmed E-Beam, mechanical stamping or by other methods. The degradable mask is not attacked by the metal paste. It is thermoplastic and volatilizes completely during the firing of the ceramic green sheets.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 69% of the total text.

Page 1 of 1

Bonded Degradable Mask

A degradable mask on ceramic green sheets is used to apply metal paste, selectively to open channels and vias cut into the ceramic green sheet by a programmed E-Beam, mechanical stamping or by other methods. The degradable mask is not attacked by the metal paste. It is thermoplastic and volatilizes completely during the firing of the ceramic green sheets.

For processing, it is essential that the mask adheres well to the ceramic green sheet. The use of a material as a degradable mask, which has a common solvent with the binder in the ceramic green sheet increases the adhesion of the mask to the ceramic green sheet. During application of the solution of the mask material to the dried ceramic green sheet, or alternately, when the ceramic slurry is cast on a substrate which is coated by a thin layer of the mask material, the dry plastic is partially dissolved at the surface, or at least softened by the common solvent in the solution of the other plastic. This results in interdiffusion and an excellent bond between the two plastics at their interface after drying.

For example, a solution of a polyamide (nylon) in a low-molecular weight aliphatic alcohol, such as methanol, or in a mixture of methanol and trichlorethylene, is applied to a ceramic green sheet as a binder. By spraying, rolling, etc., the polyamide solution softens the surface of the polyvinyl butyral in the ceramic green sheet. After drying, the polyamide layer adheres very well to ...