Browse Prior Art Database

Mechanical Chip Attachment

IP.com Disclosure Number: IPCOM000089684D
Original Publication Date: 1977-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

McBride, DG: AUTHOR

Abstract

A mechanical chip attachment (MCA) method of interconnecting a chip to a board or a chip to a module can obviate many of the problems otherwise encountered in terms of thermal mismatch between the chip and its carrier, and also can facilitate easy rework of the module or board when a defective chip occurs.

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Mechanical Chip Attachment

A mechanical chip attachment (MCA) method of interconnecting a chip to a board or a chip to a module can obviate many of the problems otherwise encountered in terms of thermal mismatch between the chip and its carrier, and also can facilitate easy rework of the module or board when a defective chip occurs.

As shown in the figure, a basic MCA includes an epoxy board or carrier 11 having suitable signal lines 13 applied thereto in a conventional manner. In addition, the board or carrier 11 will include a plurality of dimpled chip pads 15 which are positioned to accept the chip pads 17 associated with the chip 19. The chip 19 is backbonded to a spring 21 which is contained in the cap 23, operative to ultimately enclose the chip within the cap in a manner such that pressure is exerted between the chip pads 17 of the chip and chip pads 15 on the carrier 11. Tabs 25 on the cap are adapted to be inserted in holes 27 in the board or carrier to accept and secure the cap to the board in a manner to provide the necessary pressure to the chip pads.

In one mode of operation, the chip pads 15 on the board are dimpled using mechanical means, and the chip pads on the chip 19 are comprised of chrome, copper, gold balls or inverted pyramids and adapted to mate with the dimpled pads on the board or carrier 11.

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