WIRING SUBSTRATE AND MOUNTING STRUCTURE THEREOF

摘要

PROBLEM TO BE SOLVED: To provide the mounting structure having excellent long-time stability in the arrangement of a wiring substrate such as a package to an external electric circuit substrate such as a printed substrate. SOLUTION: When a wiring substrate is constituted by arranging a metalized wiring layer 3 such as Cu on the surface or inside an insulating substrate 1, a lithium-silicate based amorphous phase of 15-60 volume % and a metal oxide crystal phase having the thermal-expansion coefficient of 6 ppm/ deg.C or more at 40-400 deg.C are included at a rate of 85-40 volume % in total. The including amount of the amorphous phase is controlled within the above described range. Thus, thermal expansion coefficent at 40-400 deg.C can be minutely controlled in the range of 8-18 ppm/ deg.C. At the same time, the Young's modulus of a sintered body is decreased, and the mounting of a printed substrate to an external electric circuit substrate having the excellent long-time stability is realized.