A ceramic base for use in, for example, a hermetically sealed integrated circuit package is herein disclosed. The ceramic base includes an outermost circumferential peripheral portion having a top surface, a bottom surface, and an inner circumferential edge surface. The peripheral portion of the ceramic base is adapted to receive a conventional integrated circuit package leadframe and ceramic lid forming the hermetically sealed integrated circuit package. Also, in accordance with the present invention, the peripheral portion of the ceramic base is made from a low thermal conductivity ceramic material. The ceramic base also includes a central portion surrounded by the peripheral portion. The central portion has a top surface, a bottom surface, and an outer circumferential edge surface. The central portion of the ceramic base is adapted to have an integrated circuit die attached directly to the top surface of the central portion. And in accordance with the present invention, the central portion of the ceramic base is made from a high thermal conductivity ceramic material thereby reducing the thermal resistance of the integrated circuit package.