Electronics cooling

About: Electronics cooling is a research topic. Over the lifetime, 1135 publications have been published within this topic receiving 17608 citations.

Stereolithographically fabricated aluminum nitride microchannel substrates for integrated power electronics cooling

Abstract: The presence of multiple thermally resistive layers in power electronics packages diminishes the enhanced convective benefit of high-performance microchannel cold plates. One improvement reported here is the development of stereolithographically defined aluminum nitride (AlN) microchannel integrated coldplates as substrates for power electronics packages. High-resolution fabrication of green ceramic parts using a standard stereolithography machine has been enabled by the development of photosensitive ceramic materials. Complex microchannel integrated AlN substrates with simplified fluid connections have been produced with 2-3 mm channel height and channel width down to 200 mum. This structure bypasses the majority of the traditional thermal stack, bringing the coolant closer to the heat source. The substrates were packaged and tested with 4 mm Silicon Carbide pin diodes as heat sources at pressure drops from < 1 kPa up to 70 kPa (10 psi) and power levels exceeding 80 W (500 W/cm2). Measured total thermal stack resistivity on best performing devices was about 0.1 K-cm2/W at 70 kPa (-10 psi) and 0.14 K-cm2/W at 5 kPa (-0.7 psi). Paths for further performance improvement, broadening of fabrication possibilities, and transition to real-world systems are briefly discussed.

Designing environmentally sustainable electronic cooling systems using exergo‐thermo‐volumes

Abstract: Thermo-volumes allow the design engineer to expediently understand the thermal resistance of a given cooling solution (an indicator of performance) along with its flow resistance (an indicator of the pumping power, or energy consumption, which will be required by the fluid handler). In the present work, we expand upon thermo-volumes by including the lifetime exergy cost (in units of Joules of availability destroyed) as a means to enable the consideration of resource consumption (and thus the environmental sustainability) of the cooling solution. To achieve these exergo-thermo-volumes, we reinterpret previous definitions of thermo-volumes in terms of the entropy generated during heat transfer and fluid flow. The Guoy–Stodola theorem is used to convert this entropy generation into an ‘operational’ exergy loss. Next, based on the material choice and assembly processes used in creating the product, an embedded exergy consumption that accounts for the amount of exergy destroyed during extraction, transportation and disposal of the material is attached to the operational exergy loss. Thus, the total ‘cradle-to-cradle’ exergy loss of the solution is devised. In this framework, the optimal solution will be that which destroys the minimal amount of exergy. Correspondingly, instead of relying upon the coefficient of performance (which is focused on operational consumption), we propose evaluation of cooling solutions in terms of the heat removal capacity per unit lifetime exergy consumption. The paper concludes by illustrating applicability of the method to the design of an enterprise server. It should be noted that although the paper is focused on electronics cooling solutions, the methodology is designed to be sufficiently general for use in any thermal management application. Copyright © 2009 John Wiley & Sons, Ltd.