Patent ID: 7482292

Claim:
A ceramic substrate composition comprising a glass represented by aB 2 O 3 -bRe 2 O 3 -cZnO in which Re is a rare earth element which is at least one element selected from the group consisting of lanthanum and neodymium and the molar amounts a+b+c=1; and wherein 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 connection the Points, and further comprising at least one of (a) at least one oxide selected from the group consisting of aluminum oxide and titanium oxide in an amount of 50% or less by weight of the total amount, (b) a mixed oxide ceramic material including at least one crystal phase selected from the group consisting of ReBO 3 , Re 3 BO 6 , Re(B 2 O 3 ) 3 and ReB 3 O 6 , (c) a crystallization glass that can precipitate at least one crystal phase selected from the group consisting of ReBO 3 , Re 3 BO 6 , Re(B 2 O 3 ) 3 and ReB 3 O 6 and (d) a crystallization glass that can precipitate at least one crystal phase selected from the group consisting of ReBO 3 , Re 3 BO 6 , Re(B 2 O 3 ) 3 and ReB 3 O 6 and, in addition to the rare earth oxide of the glass, a rare earth oxide comprising Re 2 O 3 .