Degradation Characterization of Thermal Interface Greases
- National Renewable Energy Laboratory (NREL), Golden, CO (United States)
- DuPont Experimental Station
Thermal interface materials (TIMs) are used in power electronics packaging to minimize thermal resistance between the heat generating component and the heat sink. Thermal greases are one such class. The conformability and thin bond line thickness (BLT) of these TIMs can potentially provide low thermal resistance throughout the operation lifetime of a component. However, their performance degrades over time due to pump-out and dry-out during thermal and power cycling. The reliability performance of greases through operational cycling needs to be quantified to develop new materials with superior properties. NREL, in collaboration with DuPont, has performed thermal and reliability characterization of several commercially available thermal greases. Initial bulk and contact thermal resistance of grease samples were measured, and then the thermal degradation that occurred due to pump-out and dry-out during temperature cycling was monitored. The thermal resistances of five different grease materials were evaluated using NREL's steady-state thermal resistance tester based on the ASTM test method D5470. Greases were then applied, utilizing a 2.5 cm x 2.5 cm stencil, between invar and aluminum plates to compare the thermomechanical performance of the materials in a representative test fixture. Scanning Acoustic microscopy, thermal, and compositional analyses were performed periodically during thermal cycling from -40 degrees Celcius to 125 degrees Celcius. Completion of this characterization has allowed for a comprehensive evaluation of thermal greases both for their initial bulk and contact thermal performance, as well as their degradation mechanisms under accelerated thermal cycling conditions.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Organization:
- DuPont Experimental Station
- DOE Contract Number:
- AC36-08GO28308
- OSTI ID:
- 1412829
- Report Number(s):
- NREL/CP-5400-70632
- Resource Relation:
- Conference: Presented at the 2017 16th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm), 30 May - 2 June 2017, Orlando, Florida
- Country of Publication:
- United States
- Language:
- English
Similar Records
Degradation Characterization of Thermal Interface Greases
Investigation of Thermal Interface Materials Using Phase-Sensitive Transient Thermoreflectance Technique: Preprint