Browse Prior Art Database

Module Cap Ledge Reform Die

IP.com Disclosure Number: IPCOM000088605D
Original Publication Date: 1977-Jul-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Barnard, DJ: AUTHOR [+3]

Abstract

Integrated circuits are packaged in modules that include a metallized ceramic substrate 10, a metal cap 12, and connecting pins 14. Integrated-circuit chips 16 are placed on the top surface of the metallized ceramic substrate 10 and circuit lines connect the chips 16 to the pins 14.

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Module Cap Ledge Reform Die

Integrated circuits are packaged in modules that include a metallized ceramic substrate 10, a metal cap 12, and connecting pins 14. Integrated-circuit chips 16 are placed on the top surface of the metallized ceramic substrate 10 and circuit lines connect the chips 16 to the pins 14.

ln order to hermetically seal the package, an epoxy sealing material is applied to the bottom surface of the metallized ceramic substrate 10. Difficulties are encountered when this back sealing material runs in between the ceramic substrate 10 and the cap 12, since the back seal material which runs in can get under the chips 16 on top of the metallized ceramic substrate and disrupt the electrical connection between the chips and the circuit lines. Previous methods that attempted to eliminate and prevent this problem made an eight-point contact at each of the corners of the cap. This caused the cap to bow between the corners, as indicated by numeral 21. The back seal material could flow between the substrate and the bowed area 21 of the cap 12.

The present method of preventing and minimizing the back seal run in is achieved by forming the lower edges of the cap against the substrate 10 with a suitable die. The edges of the cap 12 are rolled under the ceramic substrate 10, bringing the cap material into intimate confining relationship around the margins of the ceramic substrate 10.

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