Ceramic substrate with metal filled via holes for hybrid microcircuits and method of making the same

摘要: An as-fired alumina substrate for a hybrid microcircuit formed of GaAs dies operating at gigahertz frequencies has large number about 0.013" diameter via holes drilled on the surface thereof by use laser. A metal filling in each hole is with 85% sintered tungsten and 15% copper reflowed into pores to provide composition that thermal coefficient expansion substantially matches also provides hermetically sealing holes. The further provided ground plane which it mounted block serving as heat sink. high frequency fillings therein carry their internally generated sink low inductance paths microcircuit. process placing makes stencil having same thereon first squeegeeing paste predetermined amount binder substrate. After sintered, then used squeegee top tungsten.