Browse Prior Art Database

Metal Lands on Insulating Substrates

IP.com Disclosure Number: IPCOM000094016D
Original Publication Date: 1966-Apr-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Castrucci, PP: AUTHOR [+3]

Abstract

This method forms metal lands for insulating substrates. The lands are useful as either semiconductor device bonding pads, as interconnections, or as heat sinks.

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Metal Lands on Insulating Substrates

This method forms metal lands for insulating substrates. The lands are useful as either semiconductor device bonding pads, as interconnections, or as heat sinks.

Previously, lead-tin soldered metal lands were used on ceramic modules preferably as semiconductor device bonding pads. However, the internal thermal resistance of this type of pad was about 55 degrees C/watt. Significantly better metal lands are formed by preferably electrolytically plating Ni-Cu-Ni-Au layers in previously screened silver-palladium lands. The latter are deposited on a conventional alumina module, then fired and pinned with sixteen pins.

In drawing A, thirteen plated metal lands 10 are shown located in electrical contact with pins 12. There is one metal land for each of the twelve outer pins. One metal land is for each of the inner four pins.

In drawing B, four semiconductor structures 14 are shown eutectically bonded to the four lands in electrical contact with the four corner pins. Leads 16 are provided for electrical contact to adjacent lands and, therefore, provide an electrical connection to the pins electrically associated with each contacted land. The internal thermal resistance is about 45 degrees C/watt for the plated lands. This is significantly lower than that for the lead-tin solder lands.

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