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Browse Prior Art Database

Chip Attach to Metal Heat Sink

IP.com Disclosure Number: IPCOM000079619D
Original Publication Date: 1973-Aug-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Ellis, TL: AUTHOR [+4]

Abstract

Cavities 10 are etched in a metal base 11 the size of chips 12. Chips 12 are placed in the cavities 10 and cemented with pads up. The chips 10 are approximately 0.002" to 0.005" higher than the metal base 11. A dielectric material 13 is coated over the base 10 surface to fill the space between the top of the chips 12 and the metal base 10. This coating is cured and then machined flush with the top of the chips 12.

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Chip Attach to Metal Heat Sink

Cavities 10 are etched in a metal base 11 the size of chips 12. Chips 12 are placed in the cavities 10 and cemented with pads up. The chips 10 are approximately 0.002" to 0.005" higher than the metal base 11. A dielectric material 13 is coated over the base 10 surface to fill the space between the top of the chips 12 and the metal base 10. This coating is cured and then machined flush with the top of the chips 12.

Next, a film dielectric material 14 and film copper 15 is laminated over the machined surface. The Top copper 15 is etched with holes located over the chip pad areas, exposing the dielectric material 14. This dielectric material is then removed by a laser or asher down to the chip pads. Copper studs 16 are plated from the chip pads to the surface copper 15, making a connection from chip to surface. A surface fan-out pattern is etched on the outer copper 15.

This fan-out pattern could go to pin sites for through connections or to connect chip-to-chip.

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