Norton, Mass. CPS Technologies Corp. has introduced base plates, based on its aluminum silicon carbide (AlSiC) metal matrix composite material, for insulated gate bipolar transistor (IGBT) modules used in high-power traction, power control, hybrid electric vehicle power systems, and fly-by-wire applications.
The low isotropic coefficient of thermal expansion (CTE) value of AlSiC-9 (8 ppm/°C: 30 to 100°C) is compatible with the thermal expansion value of the die or substrate used in IGBT applications. The AlSiC CTE match reduces the mechanical stresses on IGBT die and substrates that is induced by thermal power cycling, which improves reliability of substrate attachment and reduces die cracking failures, said CPS.
In addition, the AlSiC CTE eliminates the need for stress compensation material layers that are required in Cu (CTE = 17 ppm/°C) base-plate assemblies, which simplifies assembly and reduces the thermal resistance of AlSiC systems. In high-power applications (>1200 V/ 400 A), IGBT modules assembled with AlSiC base plates deliver service reliability of many 10s of thousands of thermal power cycles over Cu-equivalent systems, according to the company. AlSiC meets the requirements of the Restriction of Hazardous Substances (RoHS) directive.
AlSiC is a lightweight material (1/3 that of Cu), which makes it a suitable for weight-sensitive IGBT applications. AlSiC also delivers higher strength and stiffness than Cu, which combined with its lightweight, makes AlSiC assemblies more tolerant to shock and vibration, said CPS. Standard 190 x 140 mm, 140 x 130 mm and 140 x 70 mm base-plate formats are available. Custom sizes are also offered.
Product information: IGBT base plates
CPS Technologies Corp., 1-508-222-0614, www.alsic.com