Centorr Vacuum Industries of Nashua, N.H., shipped two high-temperature sintering furnaces to a leading firm in the production of AlN substrates for the LED market in China. The designs include a graphite furnace for AlN sintering and a refractory-metal furnace rated to 1850°C (3362°F) for a secondary heating process. The refractory-metal furnace will be used for a specific part of the AlN process where a non-graphite hot zone is desired for material cleanliness. Both furnaces include modifications made specifically for high-temperature sintering of advanced ceramics.
Centorr’s graphite furnace includes robust graphite tube and block elements designed for use to 2250°C (4082°F) with a four-sided hot zone and integral graphite retort for excellent temperature uniformity. The rigid graphite insulation provides for long-term service even in the presence of process off-gassing and residual binder contamination, while the dual-flow Sweepgas® system allows more effective “sweeping” away of the process off-gassing. Furnace control is via PLC/programmable controllers with Centorr’s custom-designed HMI visualization interface.