March 9, 2012 — Metallic wafer supplier PLANSEE developed Mo-Cu R670, a new molybdenum-copper composite material for semiconductor wafer substrates, optimizing heat dissipation in light-emitting diodes (LEDs).
Metallic wafers are high-temperature bonded to gallium-nitride (GaN) sapphire LED wafers to serve as a heat-dissipation layer in the final package. To prevent semiconductor wafer defects, such as cracking, the metal wafer must match the semiconductor wafer’s coefficient of thermal expansion (CTE).
Molybdenum offers good thermal conductivity and heat resistance, but with a lower CTE than sapphire (Al2O3). The molybdenum-copper composite material R670 has a thermal conductivity of 170 W/mK and the same coefficient of thermal expansion as sapphire (6.7 ppm/K).
Also read: Present at coolingZONE LED 2012 in Berlin
PLANSEE supplies Mo-Cu wafer substrates with nickel-gold, ruthenium, chromium, silver and other interface material coatings, designed to prevent corrosion and optimize the wafer surface for bonding.
PLANSEE manufactures refractory metals and composite materials, supplying metallic wafer substrates for heat dissipation and numerous other components for the production of LED chips and LED packages. Learn more at http://www.plansee.com/en/index.htm.