Composition for ceramic substrate, ceramic substrate, method for process for producing ceramic substrate, and glass composition

Abstract

A ceramic substrate composition is provided which can be co-fired with a low-melting metal and exhibits excellent dielectric characteristics at high frequencies, particularly tens of gigahertz. The ceramic substrate composition mainly contains a glass represented by aB 2 O 3 -bRe 2 O 3 -cZnO, wherein the molar ratios (a, b, and c) fall within a region defined in a ternary composition diagram by Point A (0.4, 0.595, 0.005), Point B (0.4, 0.25, 0.35), Point C (0.52, 0.01, 0.47), Point D (0.9, 0.005, 0.095), and Point E (0.9, 0.09, 0.01).

1 . A glass composition represented by aB 2 O 3 -bRe 2 O 3 -cZnO in which Re is a rare earth element; a+b+c=1; and the molar amounts a, b, and c fall within a region defined in a ternary composition diagram by Point A (0.4, 0.595, 0.005), Point B (0.4, 0.25, 0.35), Point C (0.52, 0.01, 0.47), Point D (0.9, 0.005, 0.095), and Point E (0.9, 0.09, 0.01) or on the lines connecting those Points. 
   
   
       2 . The glass composition according to  claim 1 , wherein the rare earth element is at least one element selected from the group consisting of lanthanum and neodymium. 
   
   
       3 . The glass composition according to  claim 2 , being a crystallized glass or an amorphous glass.