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Porous Copper Billet Fabrication

IP.com Disclosure Number: IPCOM000045606D
Original Publication Date: 1983-Apr-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Moore, RJ: AUTHOR [+2]

Abstract

Chip sites on circuit modules can be dressed for the reattachment of chips by a copper billet having a silicon backing which enables closer monitoring of the site temperature, less copper oxidation, and the prevention of flux fumes flowing to the heat source.

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Porous Copper Billet Fabrication

Chip sites on circuit modules can be dressed for the reattachment of chips by a copper billet having a silicon backing which enables closer monitoring of the site temperature, less copper oxidation, and the prevention of flux fumes flowing to the heat source.

Referring to Fig. 1, diced silicon chips 1 are sputter-plated with nickle on their upper surfaces and placed within a graphite mold 2 where copper powder 3 is placed on the plated side of the silicon chip. Cover 4 is placed on the mold, and the chips are sintered to join the copper to the chips. After cool-down, the chips are removed and coined flat to the required dimensions, as in Fig. 2. Thereafter, the billets are solder-tinned at 5 and used to perform the site dressing for chips, as shown in Fig. 3, to remove residual solder 6 by the wicking action of the porous copper billet.

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