Advancements in electronic device fabrication with increasing integration levels have resulted in very
high device densities. This has led to higher power dissipation and heat fluxes, increasing integrated circuit (IC) operating temperature. High and nonuniform heat generation degrades device and system performance. Therefore,
thermal management to keep ICs within prescribed temperature limits is an important challenge for reliable and
economic performance. Cooling techniques, including liquid coolants and air conditioning (AC), have been utilized
to remove heat at the package and system level. However, these techniques must overcome high thermal impedances
and require complex integration, while global cooling is generally wasteful, inefficient, and expensive. To improve
thermal management, we have developed Si microthermoelectric coolers (μTECs) with areas as small 1E−5 cm^2 that can be integrated on -chip near local hot spots using the standard fabrication processes. While Si μTECs cannot
achieve low base temperatures, they can actively pump relatively high heat fluxes directly to a heat sink, thus reducing
local temperature increases and allowing targeted rather than global waste heat removal. We demonstrate μTECs that can pump up to 43 W/cm^2 of locally generated excess heat with no increase in chip temperature.
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Thermoelectric active cooling for transient hot spots in microprocessors
Modern microprocessor performance is limited by local hot spots induced at high frequency by busy integrated circuit elements such as the clock generator. Locally embedded thermoelectric devices (TEDs) are proposed to perform active cooling whereby thermoelectric effects enhance passive cooling by the Fourier law in removing heat from the hot spot to colder regions. To mitigate transient heating events and improve temperature stability, we propose a novel analytical solution that describes the temperature response of a periodically heated hot spot that is actively cooled by a TED driven electrically at the same frequency. The analytical solution that we present is validated by experimental data from frequency domain thermal reflectance (FDTR) measurements made directly on an actively cooled Si thermoelectric device where the pump laser replicates the transient hot spot. We herein demonstrate a practical method to actively cancel the transient temperature variations on circuit elements with TEDs. This result opens a new path to optimize the design of cooling systems for transient localized hot spots in integrated circuits.
more » « less- NSF-PAR ID:
- 10508324
- Publisher / Repository:
- Nature Publishing Group
- Date Published:
- Journal Name:
- Nature Communications
- Volume:
- 15
- Issue:
- 1
- ISSN:
- 2041-1723
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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