Solder Matrix Fiber Composite Thermal Interface Materials
This thesis thoroughly reviews the overall status of the field of TIM research, and identifies three main tracks for novel research. First, particle laden polymers, which utilizes thermally conductive particles inside a polymer matrix which can conform to surfaces. Second, continuous metal phase TIM, which forms metallurgical bonds to both surfaces, and utilizes the inherently high thermal conductivity of metals. Third, carbon nanotube (CNT) array TIMs, which utilize the incredible thermal conductivity of CNTs. Here, an array of vertically aligned CNTs is used as nanosprings to connect the two surfaces together. In addition to these main tracks, various novel ideas based on polymers, metal and carbonaceous materials are explored.
From the reviewed categories, continuous metal phase TIM in the form of solder is already widely used in industry, but comes with severe drawbacks in terms of mechanical properties and handling issues. Solder matrix fiber composites (SMFCs) have been shown to address these challenges, but have so far required complicated procedures and components. In this thesis, we present the fabrication of a new SMFCs based on commercially available polymer and carbon fiber networks infiltrated with Sn-Ag-Cu alloy (SAC) or Indium using equipment for large volume production. The composite material exhibits similar thermal properties compared to pure solder, and mechanical properties that can be tailored towards specific applications. We also show that the handling properties of the SMFC allows it to be used in process flows where multiple reflow cycles are required, and can achieve a well-defined bond line thickness and good bonding using fluxless reflow under pressure.
thermal interface material
Chalmers, Mikroteknologi och nanovetenskap, Elektronikmaterial
Novel nanostructured thermal interface materials: a review
International Materials Reviews,; Vol. 63(2018)p. 22-45
Fabrication and characterization of a carbon fiber solder composite thermal interface material
2017 IMAPS Nordic Conference on Microelectronics Packaging (NordPac),; (2017)p. 97-100
Paper i proceeding
Josef Hansson, Torbjörn Nilsson, Lilei Ye, Johan Liu; Effect of fiber concentration on mechanical and thermal properties of a solder matrix finer composite thermal interface material
Metallurgi och metalliska material
Annan elektroteknik och elektronik
Technical report MC2 - Department of Microtechnology and Nanoscience, Chalmers University of Technology: 397
Opponent: Peter Melin, Ericsson AB, Sweden