Micro-machined heat pipes in silicon MCM substrates
Multichip modules (MCMs) containing power components need a substrate with excellent heat spreading capability both to avoid hot spots and to move dissipated heat toward the system heat sinks. Polycrystalline diamond is an excellent MCM heat spreading substrate but remains several orders of magnitude too expensive and somewhat more difficult to process than conventional mother-board materials. Today`s power MCMs concentrate on moderately priced silicon wafers and aluminum nitride ceramic with their improved thermal conductivity and good thermal expansion match to power semiconductor components, in comparison to traditional alumina and printed wiring board materials. However, even silicon and AlN substrates are challenged by designers` thermal needs. We report on the fabrication of micro-heat pipes embedded in silicon MCM substrates (5{times}5 cm) by the use of micromachined capillary wick structures and hermetic micro-cavities. This passive microstructure results in more than a 5 times improvement in heat spreading capability of the silicon MCM substrate over a large range of power densities and operating temperatures as compared with silicon alone. Thus diamond-like cooling is possible at silicon prices.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 197226
- Report Number(s):
- SAND--95-3055C; CONF-960250--1; ON: DE96004314
- Country of Publication:
- United States
- Language:
- English
Similar Records
Thermal management of a high power multichip module in a space environment
Silicon heat pipes for cooling electronics