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Elimination of Blistering on Multilayer Ceramic Sintering Substrates

IP.com Disclosure Number: IPCOM000087536D
Original Publication Date: 1977-Feb-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 45K

Publishing Venue

IBM

Related People

Light, GS: AUTHOR [+2]

Abstract

A walking beam furnace shown in Fig. 1 (side view) and Fig. 2 (top view) is designed to sinter multilayer ceramic (MLC) substrates. Bulges or blisters usually appear on the surface of the MLC substrate after sintering. If the bulge height is large, the sintered substrate's chip joint process will be affected. Using larger tile spacing during substrate sintering has proven to be quite helpful in reducing the bulge height to an acceptable level. The reasons for this improvement are due to the fact that: (1) Large tile spacing at sintering increases gas and thermal transfer in the furnace. (2) An even sintering rate will be created between the edge and the center of the substrate.

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Elimination of Blistering on Multilayer Ceramic Sintering Substrates

A walking beam furnace shown in Fig. 1 (side view) and Fig. 2 (top view) is designed to sinter multilayer ceramic (MLC) substrates. Bulges or blisters usually appear on the surface of the MLC substrate after sintering. If the bulge height is large, the sintered substrate's chip joint process will be affected. Using larger tile spacing during substrate sintering has proven to be quite helpful in reducing the bulge height to an acceptable level. The reasons for this improvement are due to the fact that: (1) Large tile spacing at sintering increases gas and thermal transfer in the furnace. (2) An even sintering rate will be created between the edge and the center of the substrate.

In order to eliminate the blistering on the sintered MLC substrates, the spacing rules for substrate sintering configuration are: A = Spacing between ceramic tiles (vertical). B = The height of sintered substrate. C = Spacing between ceramic tiles (horizontal x direction). D = Dimension of the ceramic tile (length and width). E = Spacing between ceramic tiles (horizontal y direction).

The walking beam furnace sintering configuration spacing rules are: (1) A = 2B. (2) C = 20% D. (3) E = 15% D.

The rules have to be followed in order to sinter 4-to-6-layer substrates in forming gas or low-dew point (300 degree C) conditions, without getting blistering on the sintered substrates.

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