Semester
Spring
Date of Graduation
2025
Document Type
Thesis
Degree Type
MS
College
Statler College of Engineering and Mineral Resources
Department
Mechanical and Aerospace Engineering
Committee Chair
Hailin Li
Committee Co-Chair
Bhaskaran Gopalakrishnan
Committee Member
Songgang Qiu
Abstract
Humanity has worked copper for millennia, from primitive tools in prehistory to the wires and cooling solutions facilitating the modern digital age. While high performance fin style heatsinks are commonplace, more complex heatsink geometries in high performance applications are rare due to manufacturing challenges. In this study a casting process was developed to fabricate copper pin fin heatsinks. To assess the performance of heatsinks fabricated using the process three pin fin heatsinks were fabricated, one machined from a commercially manufactured billet, one machined from a cast block, and one cast directly to final shape. Each of the three heatsinks were geometrically identical, featuring 30 staggered pin fins, 3.5 mm in diameter and 5 mm long, within a 32 mm by 44 mm rectangular heat transfer surface. The total surface area exposed to the working fluid was approximately 3,000 mm2, while without the pins the surface area would be approximately 1,400 mm2. The effect of the 30 pin fins on heat transfer was examined by comparing the performance of these three heatsinks with a fourth heatsink featuring a flat heat transfer surface with no fins machined from a billet. The heat transfer performance of all four heatsinks was experimentally measured using a purpose built testbench developed to quantify how the casting fabrication process affects heat transfer performance. The results of testing were repeatable for each heatsink with clear performance differentials between each heatsink tested. It was found that a machined surface finish rather than the cast surface finish characteristic of the process developed as part of this research resulted in a 2% improvement in heat transfer while the heatsink machined from billet transferred 11% more heat than a heatsink cast directly to final shape. To test the limits of the casting process several more complex geometries were fabricated including a heatsink featuring 1,105 cylindrical fin pins, 1.0 mm in diameter and 7.5 mm in length within a 60 mm by 60 mm region. The total surface area exposed to the working fluid was approximately 29,000 mm2, while without the pins the surface area would be approximately 3,600 mm2. The geometric flexibility and production rate made possible by this fabrication technique allows for the mass production of heatsink designs currently restricted to high cost, low volume manufacturing technologies.
Recommended Citation
Recktenwald, John James, "Fabrication and Characterization of Cast Copper Heatsinks for Computer Chip Cooling" (2025). Graduate Theses, Dissertations, and Problem Reports. 12792.
https://researchrepository.wvu.edu/etd/12792