Abstract: In a package comprising a ceramic member so as to accommodate a semiconductor device, a composite metal body which comprises copper and either one of tungsten and molybdenum is brought into contact with the ceramic member. The composite metal body is provided by impregnating molten copper into a porous block of tungsten or molybdenum and changeable in a thermal expansion coefficient and a thermal conductivity by controlling an amount of copper. The composite metal block may be used as a support for supporting the semiconductor device and/or as a heat sink for dissipating heat radiated from the semiconductor device. Preferably, the composite metal body comprises, by weight, 1-30% of copper and 99-70% of tungsten or molybdenum.

Abstract: A luminescent display panel comprises a substrate assembly comprising a solid insulator substrate and an underlying and an overlying insulator layer successively thereon, a glass cover, and a sealing layer sealing the glass cover and the substrate assembly to enclose a vacuum space where electrodes of the panel are placed. Use is made of a sealing mass for positively eliminating slow leak which otherwise occurs if at least one of the leads for the electrodes interposed between the insulator layers is extended outwardly of the vacuum space continuously along the overlying layer. The sealing mass may comprise that portion of the underlying layer which lies across the sealing layer, with all leads laid directly on the solid substrate at their portions extended across the sealing layer.