Multilayered ceramic board, method for fabricating the same, and electronic device using multilayered ceramic board

Claim 2

1 . A method for fabricating a multilayered ceramic board comprising: providing a green laminate comprising a plurality of green base layers, at least one green constraining layer disposed in contact with a principal surface of at least one of the green base layers, and at least one wiring conductor disposed on a green base layer, wherein the green base layer comprises a low-temperature sinterable ceramic material comprising a ceramic powder and a glass component, and a binder; and the green constraining layer comprises an inorganic material powder which is not sintered at the sintering temperature of the low-temperature sinterable ceramic material; and firing the green laminate at the sintering temperature for the low-temperature sinterable ceramic material, wherein the firing comprises binder removal for removing the binder contained in the green base layers and sintering for obtaining the sintered state of the low-temperature sinterable ceramic material in which the ceramic powder is densified while the glass component is fluidized in the green base layer, and wherein the rate of temperature increase from the binder removal to the sintering is more than about 20° C./minute.

Claim 3

2 . A method for fabricating a multilayered ceramic board according to claim 1 , wherein green constraining layers are disposed on both ends in the lamination direction of the laminate, and the method further comprises removing the green constraining layers disposed on both ends in the lamination direction of the laminate after the firing.

Claim 4

3 . A method for fabricating a multilayered ceramic board according to claim 2 , further comprising mounting an electronic component on an external surface of the laminate after the firing.

Claim 5

4 . A method for fabricating a multilayered ceramic board according to claim 3 , wherein the rate of temperature increase from the binder removal to the sintering is at least 25° C./minute.

Claim 6

5 . A method for fabricating a multilayered ceramic board according to claim 4 , wherein the glass precipitates a crystalline substance before the firing is complete.

Claim 7

6 . A method for fabricating a multilayered ceramic board according to claim 5 , wherein glass is a borosilicate glass.

Claim 8

7 . A method for fabricating a multilayered ceramic board according to claim 6 , wherein borosilicate glass is forsterite, akermanite or diopside.

Claim 9

8 . A method for fabricating a multilayered ceramic board according to claim 1 , wherein the rate of temperature increase from the binder removal to the sintering is at least 25° C./minute.

Claim 10

9 . A method for fabricating a multilayered ceramic board according to claim 1 , wherein the glass precipitates a crystalline substance before the firing is complete.

Claim 11

10 . A method for fabricating a multilayered ceramic board according to claim 9 , wherein glass is a borosilicate glass.

Claim 12

11 . A method for fabricating a multilayered ceramic board according to claim 10 , wherein borosilicate glass is forsterite, akermanite or diopside.

Claim 13

12 . A method for fabricating a multilayered ceramic board according to claim 1 , further comprising forming said green laminate.

Claim 14

13 . A multilayered ceramic board obtained by a method for fabricating a multilayered ceramic board according to claim 1 .

Claim 15

14 . An electronic device comprising a multilayered ceramic board according to claim 13 and a motherboard for fixing the multilayered ceramic board.

Claim 16

15 . A method for fabricating a multilayered ceramic board comprising: providing a green laminate comprising a plurality of green base layers, at least one green constraining layer disposed in contact with a principal surface of at least one of the green base layers, and at least one wiring conductor disposed on a green base layer, wherein the green base layer comprises a low-temperature sinterable ceramic material comprising a ceramic powder and a glass component which can precipitate a crystalline substance, and a binder; and the green constraining layer comprises an inorganic material powder which is not sintered at the sintering temperature of the low-temperature sinterable ceramic material; and firing the green laminate at the sintering temperature for the low-temperature sinterable ceramic material, wherein the firing comprises binder removal for removing the binder contained in the green base layers and sintering for obtaining the sintered state of the low-temperature sinterable ceramic material in which the ceramic powder is densified while the glass component is fluidized in the green base layer, and wherein the rate of temperature increase during firing is controlled so that the glass component precipitates a crystalline substance after the ceramic powder is densified.

Claim 17

15 . A method for fabricating a multilayered ceramic board comprising: providing a green laminate comprising a plurality of green base layers, at least one green constraining layer disposed in contact with a principal surface of at least one of the green base layers, and at least one wiring conductor disposed on a green base layer, wherein the green base layer comprises a low-temperature sinterable ceramic material comprising a ceramic powder and a glass component which can precipitate a crystalline substance, and a binder; and the green constraining layer comprises an inorganic material powder which is not sintered at the sintering temperature of the low-temperature sinterable ceramic material; and firing the green laminate at the sintering temperature for the low-temperature sinterable ceramic material, wherein the firing comprises binder removal for removing the binder contained in the green base layers and sintering for obtaining the sintered state of the low-temperature sinterable ceramic material in which the ceramic powder is densified while the glass component is fluidized in the green base layer, and wherein the rate of temperature increase during firing is controlled so that the glass component precipitates a crystalline substance after the ceramic powder is densified.

Claim 18

16 . A method for fabricating a multilayered ceramic board according to claim 15 , wherein green constraining layers are disposed on both ends in the lamination direction of the laminate and the method further comprises removing the green constraining layers disposed on both ends in the lamination direction of the laminate after the firing.

Claim 19

17 . A method for fabricating a multilayered ceramic board according to claim 16 , further comprising mounting an electronic component on an external surface of the laminate after the firing.

Claim 20

18 . A method for fabricating a multilayered ceramic board according to claim 15 , further comprising forming said green laminate.

Claim 21

19 . A multilayered ceramic board obtained by a method for fabricating a multilayered ceramic board according to claim 14 .

Claim 22

20 . An electronic device comprising a multilayered ceramic board according to claim 19 and a motherboard for fixing the multilayered ceramic board.