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Scaling Up Glass-Ceramic Sintering--Use of Air or N2 + 02 Bleeding Along With Steam During Oxidation

IP.com Disclosure Number: IPCOM000036809D
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 3 page(s) / 37K

Publishing Venue

IBM

Related People

Bezama, RJ: AUTHOR [+5]

Abstract

Glass-ceramic/copper substrates having a higher density and a more uniform sintering will be achieved if the binder burn-off (carbon oxidation) procedures disclosed in this article are employed. In addition, shorter steam cycle times and a minimum mass flow effects will result when the substrate and the gas phase are separated by a porous medium or substrate size/thickness is increased.

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Scaling Up Glass-Ceramic Sintering--Use of Air or N2 + 02 Bleeding Along With Steam During Oxidation

Glass-ceramic/copper substrates having a higher density and a more uniform sintering will be achieved if the binder burn-off (carbon oxidation) procedures disclosed in this article are employed. In addition, shorter steam cycle times and a minimum mass flow effects will result when the substrate and the gas phase are separated by a porous medium or substrate size/thickness is increased.

Sintering cycles for glass-ceramic/Cu multilayer substrates exist in the following categories: (1) A sintering cycle where the substrate is directly

exposed to the gas phase; and

(2) A sintering cycle where the mass transfer between

the substrate and the gas-phase is mediated by the

use of a porous medium.

It is well known that the carbon oxidation rate by steam, during glass-ceramic/Cu sintering, decreases substantially with an increase in the hydrogen (H2) concentration in the steam. On the other hand, a certain minimum hydrogen concentration is needed to maintain copper as the metal without oxidation. This minimum hydrogen concentration is given as follows: Binder Oxidation Temp., oC H 2 Concentration in

Steam, ppm

600 2.5

750 12

900 43

The maximum carbon oxidation rate in steam is, therefore, obtained when the hydrogen concentration is not too much above the minimum value given above.

In practice, when the residual carbon in glass-ceramic/copper substrate is first oxidized by s...