Additively Manufactured Ceramic Coolers for Advanced Liquid Cooling Solutions: Design, Optimization, And Characterization

Abstract:

This research aims to develop and optimize advanced liquid cooling techniques for microchips and to evaluate the opportunities to exploit the design possibilities enables by the advances in additive manufacturing, focusing on impingement and microchannel liquid cooling and heat spreading techniques using additively manufactured ceramics. The study will involve the design optimization and manufacturing of ceramic chip coolers and their thermal-mechanical characterization. The research will be conducted in a collaboration between imec and the mechanical engineering department of KU Leuven.

Background:

Effective chip cooling is crucial due to the increasing heat generated by powerful microchips, which impacts performance, reliability, and energy efficiency. As devices become smaller and more densely packed, managing heat becomes more challenging. Innovations like direct-to-chip cooling and microfluidics, along with advanced materials and manufacturing techniques, are essential to address these thermal challenges. Efficient cooling solutions not only prevent overheating and damage but also enhance the overall energy efficiency of electronic devices and data centers, supporting the next generation of microchips. For AI chips, effective cooling is even more critical due to their high-power consumption and heat generation. Proper cooling ensures AI chips can operate at peak performance, maintain reliability, and support the heavy computational demands of AI tasks.

Objectives:

1. Design and optimize chip coolers considering impingement cooling and microchannel parameters.
2. Critically assess what shapes, dimensions, etc are feasible with additive manufacturing (AM), and what is needed for an efficient design and if process needs to be adapted.  With such bilateral considerations, AM and laser surface processing of ceramic SiC will be utilized to fabricate the single-phase liquid cooling solution.
3. Perform thermal characterization of the coolers using custom-designed microchips with integrated thermal elements and sensors in a thermal test rig.
4. Assess the thermal & mechanical properties of the interfaces such as interfacial thermal resistance and adhesion.

Research Plan:

1. Design and Optimization of Chip Coolers:

Investigate thermofluid impact of parameters (e.g., nozzle diameter, spacing, channel dimensions) and optimize using computational fluid dynamics (CFD) simulations in close collaboration with the manufacturing experts to consider the manufacturing constraints in the design space. This task will be conducted within the thermal team of imec with support of imec’s thermal experts. Close cooperation with the manufacturing experts from the mechanical engineering department of KU Leuven is required to take account of manufacturing constraints in the design.

2. Additive Manufacturing and Laser Surface Processing:

Investigate additive manufacturing techniques for fabricating ceramic SiC coolers and apply laser surface processing to enhance surface properties such as roughness. This task will be conducted within the mechanical engineering department of KU Leuven, with the support of manufacturing experts from the department.

3. Thermal and Mechanical Characterization:

Conduct experiments to measure temperature distribution and heat transfer efficiency using custom-designed thermal characterization of microchips and assess the thermal performance. Compare experimental results with simulation data to validate designs. Perform mechanical testing to evaluate the reliability of thermal interfaces such as adhesion strength between coolers and microchips. Investigate the effects of thermal cycling and mechanical stress on interface integrity. This task will be conducted within imec using the available thermal test rig and thermal microchips and existing interface characterization methods and in cooperation with the mechanical engineering department.

Expected Outcomes:

Optimized chip cooler designs with enhanced cooling performance and thermal-mechanical reliability.

Required background: Students with science and technology backgrounds e.g. physics and engineering science / technology with an interest in both modelling and experimental research are encouraged to apply. The candidate should have a collaborative mindset and be willing to cooperate with experts with multidisciplinary backgrounds.

Type of Work: 40% design and modelling, 20% experimental characterization, 40% prototype manufacturing.

Supervisory team:

Promotors: Prof. Dr. Ir. Houman Zahedmanesh (promotor), Prof. Dr. Ir. Brecht Van Hooreweder (co-promotor), Prof. Dr. Ir. Bey Vrancken (co-promotor), Dr. Ir. Herman Oprins (co-promotor)

Daily Advisors: Dr. Ir. Deewakar Sharma, Dr. Ir.  Vladimir Cherman

References:

[1]https://www.imec-int.com/en/imec-magazine/imec-magazine-february-2019/a-cold-shower-for-chips

[2] How AI is Bringing Liquid Cooling into Chip Manufacturing. https://www.nvent.com/en-us/resources/news/how-ai-is-bringing-liquid-cooling-into-chip-manufacturing.

[3] Cooling High Power Dissipating Artificial Intelligence (AI) Chips Using .... https://www.scirp.org/journal/paperinformation?paperid=135386.

[4] How AI is Bringing Liquid Cooling into Chip Manufacturing. https://www.nvent.com/en-us/resources/news/how-ai-is-bringing-liquid-cooling-into-chip-manufacturing.

[5] Cooling High Power Dissipating Artificial Intelligence (AI) Chips Using .... https://www.scirp.org/journal/paperinformation?paperid=135386.

[6] webpage of the additive manufacturing group, KU Leuven. https://www.mech.kuleuven.be/en/research/am