Low temperature co-fired ceramic circuit board
AssigneeMitsubishi Electric Corporation
InventorKazuhiro Yamaguchi
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Abstract
A low-temperature fired ceramic circuit board with little warpage, few conductor wrinkles, low hygroscopicity, excellent dielectric properties, and a glass-free flat surface formed by simultaneously firing a conductor paste and a green sheet at 800 to 900° C. The green sheet comprises (1) glass powder including 35 to 39 wt. % SiO2, 9 to 17 wt. % Al2O3, 21 to 40 wt. % B2O3, 10 to 20 wt. % R′O (R′ being at least one of Mg, Ca, and Ba), 0.2 to 2 wt. % Li2O, and 0.5 to 2 wt. % MO2 (M being at least one of Ti and Zr), and (2) alumina powder, the weight ratio of glass powder to alumina powder being 4:6 to 6:4. The conductor paste comprises Ag-containing metal particles, binder, and a heat decomposable alkali metal compound, with 0.13 to 7.8 alkali metal atoms in the paste per 100 metal atoms in the particles.
Claims12
A low-temperature fired ceramic circuit board formed by subjecting a conductor paste and a green sheet to simultaneous firing at 800 to 900° C., wherein:
- the green sheet comprises (1) a glass powder which contains 35 to 39% by weight of SiO2, 9 to 17% by weight of Al2O3, 21 to 40% by weight of B2O3, 10 to 20% by weight of R′O where R′ represents at least one kind selected from the group consisting of Mg, Ca, and Ba, 0.2 to 2% by weight of Li2O, and 0.5 to 2% by weight of MO2 where M represents at least one kind selected from the group consisting of Ti and Zr, and (2) an alumina powder at a weight ratio of the glass powder to the alumina powder of 4:6 to 6:4;
- and
- the conductor paste comprises Ag-containing metal particles, a binder component, and a heat decomposable alkali metal compound, and a content of the heat decomposable alkali metal compound is such that 0.13 to 7.8 alkali metal atoms are contained for each 100 metal atoms in the metal particles.
A low-temperature fired ceramic circuit board formed by subjecting a conductor paste and a green sheet to simultaneous firing at 800 to 900° C., wherein:
- the green sheet comprises (1) a glass powder which contains 37 to 39% by weight of SiO2, 12 to 16% by weight of Al2O3, 22 to 30% by weight of B2O3, 10 to 20% by weight of R′O where R′ represents at least one kind selected from the group consisting of Mg, Ca, and Ba, 0.2 to 2% by weight of Li2O, and 0.5 to 2% by weight of MO2 where M represents at least one kind selected from the group consisting of Ti and Zr, and (2) an alumina powder at a weight ratio of the glass powder to the alumina powder of 4:6 to 6:4;
- and
- the conductor paste comprises Ag-containing metal particles, a binder component, and a heat decomposable alkali metal compound, and a content of the heat decomposable alkali metal compound is such that 0.78 to 4.8 alkali metal atoms are contained for each 100 metal atoms in the metal particles.
Dependencies are inferred from the claim text.