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Multilevel Ceramic Device with Matched Conductive Layers

IP.com Disclosure Number: IPCOM000093639D
Original Publication Date: 1967-Nov-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Neisser, KE: AUTHOR [+2]

Abstract

This multilevel ceramic device includes matched conductive layers. The latter, in addition to functioning as voltage signal or ground planes and dissipating heat, equalize internal compressive and tensile stresses developed during firing to provide a flat-fired structure.

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Multilevel Ceramic Device with Matched Conductive Layers

This multilevel ceramic device includes matched conductive layers. The latter, in addition to functioning as voltage signal or ground planes and dissipating heat, equalize internal compressive and tensile stresses developed during firing to provide a flat-fired structure.

A plurality of low firing temperature, green ceramic sheets is formed as by separate dry pressing operations or cutting the plurality from flexible ceramic tapes. A metallizing composition is deposited as by silk screening on a green sheet located at a suitable distance from the surface upon which heat-producing chip devices are to be attached. A conductive sheet is formed as by cutting from a metallized tape to serve as a bottom surface. The sheets are stacked in registry laminates and fired.

Without proper selection of the conductive materials for the internal and external conductive layers, the structure can tend to warp or bow, as shown in A, due to compressive and tensile stresses developed during the firing step.

Matched conductive layers, such as a metallizing composition initially dispersed in a suitable binder, comprise, by weight, 0-1% Ni and 100-99% Ag for the screened layer end 0.5-5.0% Ni and 99.5-95% Ag for the tape. Stresses developed within the monolithic structure during firing are equalized and a flat- firing ceramic structure with smooth conductive layers that adhere well to the ceramic, as shown in B, is realized.

The i...