Kyocera Corporation

Yamamura Glass Co., Ltd.

Jun Tanaka

Tomoyuki Taguchi

Masami Terasawa

Hideyuki Kuribayashi

Hitoshi Oikawa

Yoshihiro Morigami

Yoshinobu Kunitomo

Tomomi Konaga

A novel crystallizable glass composition for producing a novel low temperature co-fired glass-ceramic substrate having patterns of a low electrical-resistance conductor such as Ag, Ag-Pd, Au, and/or Cu is obtained. Being subjected to a firing process, the novel crystallizable glass can precipitate mullite as main crystalline phase, and at least one subordinate crystalline phase among forsterite, spinel, sapphirine, and similar crystalline phases. And also, the novel crystallizable glass powder composition with a inorganic filler as external additive having a minimum of 1.4 m.sup.2 /g. of mean specific surface area can precipitate both mullite phase and cordierite phase. The mixing weight ratio of the filler to the crystallizable glass powder is from 0.1/99.9 to 20/80. The crystallizable glass composition comprises following oxide components expressed in terms of percent by weight on the oxide basis; 45-58% of Al.sub.2 O.sub.3, 20-35% of SiO.sub.2, 5-15% of B.sub.2 O.sub.3, 5-20% of MgO, and 0-4% of alkali metal oxide. The substrates produced from the above compositions have high flexural strength, low dielectric constant, low loss factor, and controllable thermal expansion coefficient of ranging from about 30 to about 70.times.10.sup.- 7 /.degree.C. As for the substrate containing both mullite phase and cordierite phase, as the substrate has a low thermal expansion coefficient, it can be combined with AlN to produce a composite structure package.

Composition for producing low temperature co-fired substrate

Disclosed is a package for housing semiconductor elements, which comprises an insulating substrate having in the interior thereof a cavity for attaching and housing semiconductor elements and a lid member covering said cavity, wherein the insulating substrate is composed of a mullite sintered body comprising 70 to 95% by weight of mullite and 5 to 30% by weight, as the total content, of silica (SiO.sub.2) and at least one member selected from the group consisting of magnesia (MgO) and calcia (CaO), and SiO.sub.2, MgO and CaO are present in the following composition expressed by % by weight based on the three components:

Package for housing semiconductor elements

Growing community of inventors

Kagoshima, Japan

Jun Tanaka