Browse Prior Art Database

Liquid Phase Coining for Chip Thermal Connection

IP.com Disclosure Number: IPCOM000087522D
Original Publication Date: 1977-Feb-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Koopman, NG: AUTHOR [+2]

Abstract

It is sometimes desirable to have a heat conductive path between the back side of a semiconductor chip, which is bonded face down to a substrate, and a metal cover. Prior to assembling the module, it is desirable to deform by reflowing solder with a nonwettable weight placed upon it to the desired shape and size. After solidification the weight is removed and the module is assembled.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Liquid Phase Coining for Chip Thermal Connection

It is sometimes desirable to have a heat conductive path between the back side of a semiconductor chip, which is bonded face down to a substrate, and a metal cover. Prior to assembling the module, it is desirable to deform by reflowing solder with a nonwettable weight placed upon it to the desired shape and size. After solidification the weight is removed and the module is assembled.

Examples of the process are shown in the figures. In Fig. 1A, the weight 4 is placed upon the solder 5 which is on semiconductor chip 6. The chip 6 is attached to substrate 7 by means of solder balls 8. When the solder 5 is reflowed above its softening point, the weight 4 deforms the solder, as shown in Fig. 1B, to a new shape 9. The cover or cap is then fixed to the substrate so that the solder 9 is wetted thereto and contiguous to the chip for maximum heat conductance.

Figs. 2A, B show similar solder shaping wherein the solder 10 is reflowed with a weight 11 thereon onto the module cover or cap 12 to produce solder 13 of the desired shape. The weight 11 is removed and the cap 12 with the solder 13 adhering thereto is fixed over a semiconductor device to form the finished module.

1

Page 2 of 2

2

[This page contains 3 pictures or other non-text objects]