0
Research Papers

Array of Thermoelectric Coolers for On-Chip Thermal Management

[+] Author and Article Information
Owen Sullivan1

G. W. Woodruff School of Mechanical Engineering,  Georgia Institute of Technology, Atlanta, GA 30332osullivan3@gatech.edu

Man Prakash Gupta

G. W. Woodruff School of Mechanical Engineering,  Georgia Institute of Technology, Atlanta, GA 30332

Saibal Mukhopadhyay

Department of Electrical and Computer Engineering,  Georgia Institute of Technology, Atlanta, GA 30332

Satish Kumar1

G. W. Woodruff School of Mechanical Engineering,  Georgia Institute of Technology, Atlanta, GA 30332satish.kumar@me.gatech.edu

1

Corresponding author.

J. Electron. Packag 134(2), 021005 (Jun 11, 2012) (8 pages) doi:10.1115/1.4006141 History: Received August 17, 2011; Revised February 08, 2012; Published June 11, 2012; Online June 11, 2012

Site-specific on-demand cooling of hot spots in microprocessors can reduce peak temperature and achieve a more uniform thermal profile on chip, thereby improve chip performance and increase the processor’s life time. An array of thermoelectric coolers (TECs) integrated inside an electronic package has the potential to provide such efficient cooling of hot spots on chip. This paper analyzes the potential of using multiple TECs for hot spot cooling to obtain favorable thermal profile on chip in an energy efficient way. Our computational analysis of an electronic package with multiple TECs shows a strong conductive coupling among active TECs during steady-state operation. Transient operation of TECs is capable of driving cold-side temperatures below steady-state values. Our analysis on TEC arrays using current pulses shows that the effect of TEC coupling on transient cooling is weak. Various pulse profiles have been studied to illustrate the effect of shape of current pulse on the operation of TECs considering crucial parameters such as total energy consumed in TECs peak temperature on the chip, temperature overshoot at the hot spot and settling time during pulsed cooling of hot spots. The square root pulse profile is found to be the most effective with maximum cooling and at half the energy expenditure in comparison to a constant current pulse. We analyze the operation of multiple TECs for cooling spatiotemporally varying hot spots. The analysis shows that the transient cooling using high amplitude current pulses is beneficial for short term infrequent hot spots, but high amplitude current pulse cannot be used for very frequent or long lasting hot spots.

FIGURES IN THIS ARTICLE
<>
Copyright © 2012 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

(a) Schematic of an electronic package. Heat spreader, thermal interface material (TIM), chip, substrate and thermoelectric coolers (TECs) are shown. (b) Layout of nine TECs and the associated mesh in a 2D cross-section.

Grahic Jump Location
Figure 2

(a) Temperature contours on the bottom surface of the chip with no TECs turned on. High heat flux (1000 W/cm2 ) sources are located at nine symmetrical points of area 500 × 500 μm2 which generate hot-spots. The rest of the surface has a uniform heat flux of 43 W/cm2 . (b) Temperature contours on the bottom surface of the chip with TECs turned on at 1.5 amperes.

Grahic Jump Location
Figure 3

Temperature change at the center hot spot (ΔT) for various configurations of active hot spots and TECs: (1) Only center hot spot active, (2) Hot spots 5 and 6 active, (3) Hot spots 2, 4, 5, 6, and 8 active, (4) All nine hot spots active

Grahic Jump Location
Figure 4

(a) Centerline temperatures for 1, 5, and 9 hotspots turned on; solid line is with no TEC, and dashed line is with TEC turned on with optimal steady-state current. (b) Heat passing through the cold side of the center TEC (Qin in Watts) and maximum cooling (°C) at the center hot spot when 1, 3, 5, or 9 hotspots with corresponding TECs turned on with optimal steady-state current (see Fig. 3 for optimal current).

Grahic Jump Location
Figure 5

Temperature contours in a horizontal cross-section of chip at 10 μm below the chip-TIM interface when only center hotspot is active. (a) center TEC turned on at 2 amperes, and (b) center and two adjacent TECs turned on at 2 amperes; arrow shows heat flow direction due to the active TEC at left side.

Grahic Jump Location
Figure 6

(a) Transient analysis of a single hot spot; TEC turned on with 3.0 A, 6.0 A, 8.0 A, and 10.0 A current; (b) Transient analysis with 8.0 A current for various number of hotspots and active TECs

Grahic Jump Location
Figure 7

(a) Pulse shapes used in transient analysis include constant, linear, square root, and parabolic; (b) Hot spot 5 turned on with a high heat flux of 1000 W/cm2 and allowed to reach steady-state; TEC turns on with various pulses: constant, linear, root, and parabolic

Grahic Jump Location
Figure 8

Hot spot 5 turned on with a high heat flux of 1000 W/cm2 and allowed to reach steady-state; TEC turns on with square root pulse of various periods: 2.5 ms, 5.0 ms, 10.0 ms, 15.0 ms

Grahic Jump Location
Figure 9

Hot spot 5 turns on with a high heat flux of 1000 W/cm2 and TEC turns on at 102 °C for various pulses: constant, linear, root and parabolic; (a) Actual temperatures of simulations, (b) Energy consumed over time

Grahic Jump Location
Figure 10

Comparison of the four pulses: (1) Constant, (2) Linear, (3) Square Root and (4) Parabolic using four parameters important to select a pulse: (a) Difference between maximum temperature and threshold temperature (∼102 °C), (b) Temperature overshoot after pulse is turned off, (c) Total energy expended during pulsed operation and (d) Settling time for temperature within 0.5 °C of steady-state

Grahic Jump Location
Figure 11

(a) Random cycling of hot spots 3, 5 and 6, respectively; (b) Transient temperature at hot spots when TECs turned on with square root pulse at hot spot temperature >102 °C during random cycling of hot spots

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In