Heat removal from a silicon chip using a liquid cooled microchannel

Abstract

The objective of this study was to theoretically and experimentally evaluate the heat transfer characteristics of liquid forced convection i• n microchannels. An apparatus was constructed to hold and direct coolant to a 500 μm wide by 15 μm deep channel in a small silicon chip. The small dimensions of the coolant channels produce an exceedingly high convective heat transfer film coefficient. The holding device contained small resistors embedded beneath the chip to simulate energy generation. The increasing need for high speed computing devices has revealed a limitation in dissipated heat removal. Tuckerman (1981) suggested the use of microchannels to provide liquid cooling to electrical components. He found that 790 W/cm2 could be removed from a silicon chip using an arrangement of fins and microchannels. More recently, Phillips ( 1988) conducted further research in this area substantiating the potential of high heat removal rates using microchannels. Temperature variation within the chip was determined with the use of thermochromic liquid crystals (TLC). The TLC crystalline structure changes with temperature, thus 1• 1• affecting the reflection of incident light. The resulting color of the crystals showed thermal gradients consistent with expectations of about 4 °c from the channel to the edge of the chip. A film coefficient in the range of 150, ooo W/m2-K was predicted. This is consistent with work done by Phillips (1988). The Nusselt number for flow through the channel was experimentally determined to be in the range of 3.5 to 11. Classical theory predicts the Nussel t Number should be about 8.3 for flow through a channel with these dimensions. The apparatus was tested to an energy generation of 0.6 Watts on the 1 cm2 chip. The corresponding heat flux based on the area of the channel is 2.45 x 105 W/m2 . The energy dissipation rate tested is less than 10% of typical dissipation rates in state-of-the-art computer chips. Micro-cooling channels have the potential to enhance heat removal from computing devices. Much more design work is needed before this method can become feasible. The potential for coolant leaks in electrical components adds complications. Phillips noted that microchannels may also be useful in cooling hypersonic airfoils. Non-electrical applications such as space or aircraft surfaces may be a better area for microchannel cooling study.

Notes

This item is only available in print in the UCF Libraries. If this is your thesis or dissertation, you can help us make it available online for use by researchers around the world by STARS for more information.

Graduation Date

1992

Semester

Spring

Advisor

Gunnerson, Fred

Degree

Master of Science (M.S.)

College

College of Engineering

Department

Mechanical and Aerospace Engineering

Format

PDF

Pages

79 p.

Language

English

Length of Campus-only Access

None

Access Status

Masters Thesis (Open Access)

Identifier

DP0029731

Subjects

Dissertations, Academic -- Engineering; Engineering -- Dissertations, Academic

This document is currently not available here.

Share

COinS
 

Accessibility Statement

This item was created or digitized prior to April 24, 2026, or is a reproduction of legacy media created before that date. It is preserved in its original, unmodified state specifically for research, reference, or historical recordkeeping. In accordance with the ADA Title II Final Rule, the University Libraries provides accessible versions of archival materials upon request. To request an accommodation for this item, please submit an accessibility request form.