Browse Prior Art Database

Surface-Mounted Inverted Module

IP.com Disclosure Number: IPCOM000037982D
Original Publication Date: 1989-Sep-01
Included in the Prior Art Database: 2005-Jan-31
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Hsiao, R: AUTHOR [+6]

Abstract

Disclosed is a surface mounting module assembly that makes available increased circuit wiring density and thermal enhancement, while providing device burn-in capability prior to card assembly.

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This is the abbreviated version, containing approximately 100% of the total text.

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Surface-Mounted Inverted Module

Disclosed is a surface mounting module assembly that makes available increased circuit wiring density and thermal enhancement, while providing device burn-in capability prior to card assembly.

Ceramic substrates (1) are circuitized using standard Metallized Ceramic (MC) technology on a single layer (2). This circuitization provides wiring from the device interconnection to assembly pads distributed at repeated intervals on the substrates. A sub-assembly is built by joining a device via the C4 technology to the chip site and solder coated copper balls reflowed to the assembly pads (3). Electrical test and burn-in (as required) is performed on this sub-assembly. Devices are encapsulated (4) and component part number applied. Circuit cards with thermal expansion matching power planes (to closely match the thermal expansion of the card and ceramic) are screened with eutectic solder paste on pads (5) that correspond to substrate copper balls. Sub-assemblies are then joined to the cards.

Two thermal enhancements are available. Attachment of a heat sink with a thermally conductive adhesive to the top surface of the ceramic is the simplest method. When improved thermal dissipation is required, heat sinks can be soldered to a metallized surface on the back of the ceramic substrate (6).

(Image Omitted)

Disclosed anonymously.

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