Claims
- 1. A multilayer alumina-based wiring substrate, comprising:
- (i) a high dielectric layer defining sides, the high dielectric layer comprising:
- alumina particles,
- a high permittivity-imparting agent selected from a group consisting of (a) at least one of W and Mo, (b) Re and (c) zirconia, and
- a grain boundary having a glass phase comprising alumina and at least one component selected from silica, an alkaline earth metal, and a rare earth element,
- (ii) a pair of electrode layers provided on the sides of the high dielectric layer, each of the electrode layers comprising at least one of W and Mo as a main component, and
- (iii) insulation layers comprising alumina particles and a glass phase comprising alumina and at least one component selected from silica, an alkaline earth metal and a rare earth element, the high dielectric layer and the electrode layers being disposed between the insulation layers.
- 2. The wiring substrate of claim 1, wherein the high dielectric layer comprises a sintered mixture comprising 67 to 87% by weight of an alumina powder, 5 to 30% by weight of at least one of a W powder and an Mo powder, and at least 3% by weight of at least one powder selected from silica, an alkaline earth metal and a rare earth element.
- 3. The wiring substrate of claim 1, wherein the high dielectric layer comprises a sintered mixture comprising 40 to 95% by weight of an alumina powder, 5 to 60% by weight of Re, and at least 3% by weight of at least one powder selected from silica, an alkaline earth metal and a rare earth element.
- 4. The wiring substrate of claim 1, wherein the high dielectric layer comprises a sintered mixture comprising 10 to 90% by weight of an alumina powder, 10 to 90% by weight of a zirconia powder, and at least one powder selected from silica, an alkaline earth metal and a rare earth element.
- 5. The wiring substrate of claim 1, wherein the high permittivity-imparting agent of the high dielectric layer comprises W and the electrode layers comprise W as a main component.
- 6. The wiring substrate of claim 1, wherein the high permittivity-imparting agent of the high dielectric layer comprises Mo and the electrode layers comprise Mo as a main component.
- 7. The wiring substrate of claim 1, wherein the high permittivity-imparting agent of the high dielectric layer comprises W, the electrode layer comprises Mo as a main component, and the dielectric layer has a thickness of at least 30 .mu.m.
- 8. The wiring substrate of claim 1, wherein the high permittivity-imparting agent of the high dielectric layer comprises Mo, the electrode layer comprises W as a main component, and the dielectric layer has a thickness of at least 30 .mu.m.
- 9. The wiring substrate of claim 1, wherein the high permittivity-imparting agent comprises ZrO2 and at least one of Mo, W and Re, wherein the Mo is present in an amount equal to 5 to 30% by weight based upon the total amount of the high dielectric layer, wherein the W is present in an amount equal to 5 to 50% by weight based upon the total amount of the high dielectric layer, and wherein the Re is present in an amount equal to 10 to 60% by weight based upon the total amount of the high dielectric layer.
- 10. The multilayer alumina-based wiring substrate of claim 1 further comprising a package for a semiconductor device in which the multilayer alumina-based wiring substrate is provided.
Priority Claims (3)
Number |
Date |
Country |
Kind |
4-230993 |
Aug 1992 |
JPX |
|
4-230994 |
Aug 1992 |
JPX |
|
5-171844 |
Jul 1993 |
JPX |
|
Parent Case Info
This is a continuation of application Ser. No. 385,747 filed Feb. 8, 1995, now abandoned, which is itself a continuation of application Ser. No. 08/114,482 filed on Aug. 31, 1993 and now abandoned.
US Referenced Citations (11)
Foreign Referenced Citations (1)
Number |
Date |
Country |
45722 |
Nov 1977 |
JPX |
Continuations (2)
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Number |
Date |
Country |
Parent |
385747 |
Feb 1995 |
|
Parent |
114482 |
Aug 1993 |
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