DOUBLE-LAYER GLASS PREPARATORY MOLDED ARTICLE FOR COMPRESSION AIRTIGHT SEALING OF GLASS AND METAL

摘要

A duplex glass preform (30) for forming hermetic glass-to-metal seals of the compression type. The duplex glass preform (30) comprises a glass infrastructure or matrix having at least one end thereof modified by the selective distribution therein of ceramic particles (54). The ceramic particles (54) are selectively distributed to form a ceramic density gradient having the largest concentration of ceramic particles at the surface and gradually decreasing with depth. The duplex glass preform of the present invention has utility in forming glass-to-metal compression seals in hybrid metal packages containing microcircuit chips.