Browse Prior Art Database

Electrode with Improved Adhesion

IP.com Disclosure Number: IPCOM000093901D
Original Publication Date: 1966-Mar-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Milkovich, SA: AUTHOR [+2]

Abstract

This electrode paste has greatly increased adhesion to its supporting dielectric substrate. This is due to the presence of a small percentage of an additive. An electrode is formed by applying to and then firing on an alumina ceramic substrate a conductive metallizing paste. The electrode is formed into a desired circuit pattern providing a conductive path between clips, leads or pins attached to or embedded in the substrate. Planar semiconductor or chip devices are bonded to the electrode after pretinning the pattern with solder.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 79% of the total text.

Page 1 of 1

Electrode with Improved Adhesion

This electrode paste has greatly increased adhesion to its supporting dielectric substrate. This is due to the presence of a small percentage of an additive. An electrode is formed by applying to and then firing on an alumina ceramic substrate a conductive metallizing paste. The electrode is formed into a desired circuit pattern providing a conductive path between clips, leads or pins attached to or embedded in the substrate. Planar semiconductor or chip devices are bonded to the electrode after pretinning the pattern with solder.

The electrode paste includes solids and an inert liquid vehicle commonly composed of a resinous binder, a voltizable solvent and a surfactant. The solids normally comprise a mixture of gold and platinum particles dispersed in a vitreous flux composed of bismuth trioxide and cadmium borosilicate glass. Such paste does not leave a conductive residue on the ceramic when the substrate is stressed during handling of pins, clips or leads, thus preventing proper circuit functioning.

The addition of 5%, by weight, of lead bisilicate to such a paste increases tensile strength, shock resistance and peel strength as much as two times. A conductive residue remains on the substrate after adhesive failure. The residue allows proper circuit functioning to continue. a preferred formulation for the electrode paste, which is typically applied by silk screening and fired at 800-900 degrees, is, by weight, 5% lead bisilicat...