Browse Prior Art Database

Thermal Piston with Resilient Multi-point Contact

IP.com Disclosure Number: IPCOM000050875D
Original Publication Date: 1982-Dec-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Chu, RC: AUTHOR [+2]

Abstract

Integrated circuit semiconductor chips generate a great deal of heat during operation. The use of spring-biased pistons to conduct the heat away is commercially used today.

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Thermal Piston with Resilient Multi-point Contact

Integrated circuit semiconductor chips generate a great deal of heat during operation. The use of spring-biased pistons to conduct the heat away is commercially used today.

To improve on the thermal contact between the piston and chip, there is shown (Fig. 1) a piston 10 with a plurality of heat-conducting wires 11 in contact with the surface 12 of the semiconductor chip 13, mounted on a substrate 14 by means of solder balls 15 using a known flip-chip technique. Preferably, the tip of the piston 10 is machined with a matrix of tiny holes 16. Herein, the holes are drilled at a 45 degrees angle. Short beryllium-copper wires 11 are solder reflowed into the holes 16 and project from the piston tip at an incline. Alternatively, the tip of the piston 10 may be cut with angled slots instead of drilling holes. The remaining manufacturing steps will be the same as previously described.

Fig. 2 is a cross-section of Fig. 1 along line 2 - 2, and shows the contact pattern of the tips of the wires 11 on the surface of chip 13. If different areas of the chip 13 require greater thermal conduction than other areas, the pattern can be so designed to match those areas by an increased number of contacts. In addition to providing improved thermal contact between the piston 10 and the chip 13 by using the wires 11, the loading of the wires can be designed so that force across the surface 13 of the chip is constant, thereby eliminating...