Here is the abstract you requested from the rf_2012 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.
|Thermal Pyrolytic Graphite Composite with Coefficient of Thermal Expansion Matching for Thermal Management in RF Electronics|
|Keywords: Thermal management, Thermal expansion, pyrolytic graphite|
|Thermal management is an increasingly critical problem in a variety of electronics industries, including defense, aerospace, telecommunications, and lighting. As power requirements increase and size requirements decrease, innovative materials with high thermal conductivity (TC) and coefficient of thermal expansion (CTE) matching are desired to solve these thermal challenges. In this presentation, Momentive Performance Materials introduces to the RF packaging industry a novel high-TC and CTE-matched composite based on the unique properties of thermal pyrolytic graphite (TPG). TPG with its highly-oriented graphene structure exhibits excellent in-plane thermal conductivity (>1500 W/m-K), and very low density (2.25g/cm^3). TPG composite with Al or Cu encapsulation, traditionally known as TC1050®, is a great thermal management material, but lacks CTE matching. As demonstrated in this study, bonding TPG with CTE-matched alloys, such as WCu and MoCu, simultaneously achieves high TC (>900 W/m-K) from the TPG core and low CTE (<9x10^-6/K) from the metal encapsulation. The measurement of TC and CTE as a function of TPG volume loadings on the TPG-MoCu composites, shown as examples, matches the theoretical calculation and confirms the high-TC and low-CTE claims. With both TC and CTE advantages, this CTE-matched composite can be an excellent building material for heat spreaders and heat sinks which require direct contact with electronic dies. Compared with the traditional two-component architecture (low CTE heat spreader + high TC heat sink), heat sinks made of this CTE-matched TPG composite not only increase the efficiency of thermal spreading, but also eliminate one of thermal interfaces and reduce the integration cost. The design and performance of TPG composite in several thermal management applications will also be presented in the paper.|
|Wei Fan, Lead Materials Scientist
Momentive Performance Materials Inc.