Briefly trace how the demands of electronic circuit technology have impacted on the development of ceramic ‘packaging’ technology. An alumina substrate of dimensions 1 cm*1 cm*0.5 mm carries a device...

Briefly trace how the demands of electronic circuit technology have impacted on the development of ceramic ‘packaging’ technology. An alumina substrate of dimensions 1 cm*1 cm*0.5 mm carries a device dissipating 20W. If the substrate is bonded to a metallic heat sink, estimate the steady state difference in temperatures between the surface carrying the device and the heat sink. The thermal conductivity of alumina may be taken to be 35W.