Here is the abstract you requested from the thermal_2013 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|High Thermal Conductivity Low CTE Thermal Management Products|
|Keywords: CTE Matching, High Thermal Conductivity, Reliability|
|Increasing power densities in electronic devices are driving a need for improved thermal management materials. The requirements for new materials are include high thermal conductivity for heat dissipation and low coefficient of thermal expansion to match the substrate material. The current CTE-matched materials include aluminum-silicon carbide, aluminum-silicon, copper-tungsten, and copper moly. These materials all possess a sufficiently low CTE, but lack the requisite thermal conductivity. Thermally annealed pyrolytic graphite (TPG) is a highly anisotropic form of graphite which possesses an extremely high thermal conductivity in the a-b planes. TPG encapsulated in a thin shell of CTE matched material, such as copper-tungsten, creates a composite material with exceptional thermal conductivity and maintains the CTE characteristics of the encapsulating material. TPG has been successfully encapsulated in many CTE-matched materials to create a superior thermal management product. The composite features a low CTE that can be tailored to specific requirements by careful selection of the encapsulation material. The thermal conductivity of the composite can range from 400-1000W/mK depending on the volume fraction of TPG encapsulated. This marks up to a 2.5X improvement in pure copper and has the added benefit of CTE matching. Simulation results show that using a TPG-encapsulated composite, even with the worst configuration, can result in a 15% drop in the maximum temperature experienced by the die using a modest power input. Reliability tests such as thermal cycling and shock/vibe have been conducted using this encapsulation method with no loss of thermal performance in the part. Designs of articles are able to be tailored to fit most existing geometries making these CTE-matched materials ideal drop-in solutions to thermal challenges.|
|Aaron Rape, Product Design Engineer
Momentive Performance Materials