BeO Insulator Sets Thermal Conductivity Benchmark
Providing insulation in high-power RF and microwave power transistor packages as well as electron devices such as inductive output tubes, the BW3250 beryllium oxide (BeO)material from Brush Ceramic Products delivers a thermal conductivity of greater than 325 W/mK at room temperature, an increase of over 15 percent from the 285 W/mK that was previously achievable. BeO has a low dielectric constant of 6.7 and a low loss index of 0.0012 at 1 MHz, which addresses the increase in losses that occur as frequency increases. Ceramic-to-metal joints and metalization coatings are generally very strong and reliable, and BeO is very stable in oxygen and moisture-containing environments. About 11 times more resistant to thermal shock than alumina, the material is available in plates measuring up to 4.5" × 4.5" with a material strength of 38,000 lb/in².