ALUMINA SUBSTRATE AND MULTI-LAYERED SUBSTRATE USING THE SAME

摘要

PURPOSE:To obtain an alumina substrate having high thermal conductivity and high antibending strength and capable of being sintered at low temperatures, and a multi-layered substrate using the alumina substrates and having excellent characteristics. CONSTITUTION:The multi-layered substrate produced by laminating alumina substrates 11-16 comprises highly pure fine alumina powder having an alumina content of >=99.9% and comprising primary particles each having a diameter of <=0.1mum. A low thermally expansible layer 2 having a smaller thermal expansion coefficient than the thermal expansion coefficient of the alumina substrate can be disposed on the surface of the multilayered alumina substrate 1. A heat- generating element 31 is disposed on the surface of the multi-layered alumina substrate 1, and a heat-releasing through-hole 3 penetrating the multilayered alumina substrate 1 can be disposed at a place below the heat-generating element. Passive elements such as a selfcontained capacitor 41 or a self-contained resistor 42 can be disposed in the multi-layered alumina substrate 1 and incorporatively sintered.