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Indent, Etch and Probe Test Method

IP.com Disclosure Number: IPCOM000075433D
Original Publication Date: 1971-Sep-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Berger, RG: AUTHOR [+2]

Abstract

This method provides for convenient isolation of individual circuit components on glass-coated monolithic integrated circuit modules.

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Indent, Etch and Probe Test Method

This method provides for convenient isolation of individual circuit components on glass-coated monolithic integrated circuit modules.

In order to analyze integrated circuit failures, it is desirable to physically isolate components without destroying adjacent components or the entire semiconductor circuit.

Glass-coated circuits are first coated with a 10 percent solution of wax- trichlorethyene which is then air dried to form a brittle, but etch resistant, coating over the glass. A sharp pointed instrument, such as a standard microhardness tester, is placed over the interconnection line to be disconnected and a predetermined load is applied causing the protective glass to fracture, leaving a small hole in the wax layer. The wax-coated circuit module is then placed in an etchant which selectively attacks the interconnection metallurgy, but not wax or glass, until the interconnection has been severed. If external pads are available, the isolated component may then be tested. If no external pads are available, it may be necessary to crack the glass several times over a portion of the interconnection member in order to expose a sufficient area of the severed interconnection line to allow probing. This may be accomplished by applying a compressive load to the glass below the crack threshold of the underlying interconnection line. The threshold will depend upon many parameters, but is relatively fixed for any individual type of circui...