| 摘要 |
PURPOSE:To reduce the dispersion of a resistance value by mainly comprising zinc oxide, containing aluminum oxide and magnesium oxide in specific values and containing one kind or more of borate, silicate and borosilicate group frit glass in specific values. CONSTITUTION:A ceramic material contains 0.5-40mol% aluminum oxide in terms of Al2O3, 0.5-40mol% magnesium oxide in terms of MgO, 20-99mol% zinc oxide in terms of ZnO and 0.01-2.0wt.% frit glass. Al2O3 reacts with ZnO, a double oxide crystal grain composed of ZnAl2O4 is formed, and electric resistance is increased. MgO augments electric resistance, and lowers the temperature coefficient of resistance or changes it into a positive value. ZnO is a main component, and mainly forms a conductive section. Frit glass forms liquid phase during braking, and promotes sintering. Accordingly, the size of a ZnO crystal grain is equalized, and ZnO contributes to the reduction of the dispersion of a resistance value. |
