Ceramic wiring substrate and process for producing the same
AssigneeHitachi, Ltd.
InventorsGyozo Toda, Takashi Kuroki, Shousaku Ishihara, Tsuyoshi Fujita, Naoya Kanda
Life of this patent
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Abstract
A ceramic wiring substrate and a process for producing the same having a conductive layer, obtained by sintering a conductive paste comprising 85 to 97% by weight of a tungsten powder and 15 to 3% by weight of a sintering additive (for conductive metal) having a specified composition, on a mullite ceramic substrate.
Claims8
A ceramic wiring substrate comprising a conductive layer provided on a ceramic substrate, said conductive layer being produced by sintering a conductive paste comprising 85 to 97% by weight of a tungsten powder and 15 to 3% by weight of a sintering additive (for conductive metal) having a composition falling within the range surrounded by the lines connecting points A, B, C, D, E, F, G, H, I, J, K, L, M and N and the lines connecting points O, P, Q, R and S in a triangular composition diagram,
- provided that said points A through N and O through S represent the following compositions, respectively:
- ______________________________________ SiO.sub.2 (wt %) Al.sub.2 O.sub.3 (wt %) MgO (wt %) ______________________________________ A 46 41 13 B 41 22.5 36.5 C 47 17 36 D 51 12 37 E 56 5 39 F 60 5 35 G 67 5 28 H 71 9 21 I 75 12 13 J 80 12 8 K 84 10 6 L 90 7.5 2.5 M 95 5 0 N 80 16 4 O 51 26 23 P 50.5 23 26.5 Q 55.5 18 26.5 R 63 15 22 S 64 20 16 ______________________________________
A ceramic wiring substrate comprising a conductive layer provided on a ceramic substrate, said conductive layer being produced by sintering a conductive paste comprising 75 to 95% by weight of a molybdenum powder and 5 to 25% by weight of a sintering additive (for conductive metal) having a composition falling within the range surrounded by the lines connecting points A, B, C, D, E, F, G, H, I, J, K, L, M and N and the lines connecting points O, P, Q, R and S in a triangular composition diagram,
- provided that said points A through N and O through S represent the following compositions, respectively:
- ______________________________________ SiO.sub.2 (wt %) Al.sub.2 O.sub.3 (wt %) MgO (wt %) ______________________________________ A 46 41 13 B 41 22.5 36.5 C 47 17 36 D 51 12 37 E 56 5 39 F 60 5 35 G 67 5 28 H 71 9 21 I 75 12 13 J 80 12 8 K 84 10 6 L 90 7.5 2.5 M 95 5 0 N 80 16 4 O 51 26 23 P 50.5 23 26.5 Q 55.5 18 26.5 R 63 15 22 S 64 20 16 ______________________________________
A process for producing a ceramic wiring substrate, comprising the steps of:
- conducting printing on a ceramic green sheet with a conductive paste comprising 85 to 97% by weight of a tungsten powder and 15 to 3% by weight of a sintering additive (for conductive metal) having a composition falling within the range surrounded by the lines connecting points A, B, C, D, E, F, G, H, I, J, K, L, M and N and the lines connecting points O, P, Q, R and S in a triangular composition diagram;
- and
- sintering the resulting ceramic green sheet having a printing thereon at 1550.degree. to 1700.degree. C. in a reducing atmosphere,
- provided that said points A through N and O through S represent the following compositions, respectively:
- ______________________________________ SiO.sub.2 (wt %) Al.sub.2 O.sub.3 (wt %) MgO (wt %) ______________________________________ A 46 41 13 B 41 22.5 36.5 C 47 17 36 D 51 12 37 E 56 5 39 F 60 5 35 G 67 5 28 H 71 9 21 I 75 12 13 J 80 12 8 K 84 10 6 L 90 7.5 2.5 M 95 5 0 N 80 16 4 O 51 26 23 P 50.5 23 26.5 Q 55.5 18 26.5 R 63 15 22 S 64 20 16 ______________________________________
A process for producing a ceramic wiring substrate, comprising the steps of:
- conducting printing on a ceramic green sheet with a conductive paste comprising 75 to 95% by weight of a tungsten powder and 25 to 5% by weight of a sintering additive (for conductive metal) having a composition falling within the range surrounded by the lines connecting points A, B, C, D, E, F, G, H, I, J, K, L, M and N and the lines connecting points O, P, Q, R and S in a triangular composition diagram;
- and
- sintering the resulting ceramic green sheet having a printing thereon at 1550.degree. to 1700.degree. C. in a reducing atmosphere,
- provided that said points A through N and O through S represent the following compositions, respectively:
- ______________________________________ SiO.sub.2 (wt %) Al.sub.2 O.sub.3 (wt %) MgO (wt %) ______________________________________ A 46 41 13 B 41 22.5 36.5 C 47 17 36 D 51 12 37 E 56 5 39 F 60 5 35 G 67 5 28 H 71 9 21 I 75 12 13 J 80 12 8 K 84 10 6 L 90 7.5 2.5 M 95 5 0 N 80 16 4 O 51 26 23 P 50.5 23 26.5 Q 55.5 18 26.5 R 63 15 22 S 64 20 16 ______________________________________
Dependencies are inferred from the claim text.