US 7,105,070 B2Granted

Method for producing ceramic substrate, and ceramic substrate

AssigneeNgk Spark Plug Co., Ltd.

InventorsAkifumi Tosa, Jun Otsuka, Manabu Sato, Hisahito Kashima

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Abstract

A method for producing a ceramic substrate which employs a cofiring process using restraint sheets in which a second ceramic green sheet 7 is laminated on a green ceramic substrate 30 so as to cover surface conductors 32 of the green ceramic substrate 30, the second ceramic green sheet 7 subsequently being integrated with the green ceramic substrate 30. Restraint sheets 9, which are not sintered at a sintering temperature at which the green ceramic substrate 30 is sintered, are laminated on corresponding opposite sides of the green ceramic substrate 30 so as to restrain the green ceramic substrate 30 together with the second ceramic green sheet 7. The second ceramic green sheet 7 and the green ceramic substrate 30 are fired at a temperature at which the second ceramic green sheet 7 and the green ceramic substrate 30 are integrally sintered, whereas the restraint sheets 9 are not sintered, to thereby yield a ceramic substrate 40. The restraint sheets 9 and a ceramic covering layer 7a which covers the surface conductors 32 are removed, to thereby expose the surface conductor layer 32. A plating layer 31 is formed on the surface conductor layer 32.

Claims21

Dependent claims

A method for producing a ceramic substrate, which comprises:

(a) fabricating a green ceramic substrate comprising a laminate of ceramic green sheets and conductor layers, and surface conductors formed on a main surface of the laminate;
(b) applying a ceramic paste to the green ceramic substrate so as to cover the surface conductors and the main surface of the laminate, the ceramic paste subsequently being integrated with the ceramic green sheets by cofiring;
(c) laminating a restraint sheet on each of opposite sides of the green ceramic substrate to which the ceramic paste is applied, so as to restrain the green ceramic substrate, the restraint sheets containing a predominant amount of a sintering-resistant inorganic material, which is not sintered at a sintering temperature at which the green ceramic substrate is sintered;
(d) firing the green ceramic substrate under restraint at a temperature at which the green ceramic substrate is sintered, whereas the restraint sheets are not sintered, to thereby yield a ceramic substrate restrained by means of the restraint sheets;
and
(e) removing, from the ceramic substrate restrained by means of the restraint sheets, the restraint sheets and a ceramic covering layer which is an upper portion of a ceramic layer formed from the ceramic paste applied in the covering step and which covers the surface conductors, to thereby expose the surface conductors, while leaving a lower portion of the ceramic layer formed from the ceramic paste applied in the covering step on the ceramic substrate.

3 more elements

A method for producing a ceramic substrate, which comprises:

(a) fabricating a green ceramic substrate comprising a laminate of first ceramic green sheets and conductor layers, and surface conductors formed on a main surface of the laminate;
(b) laminating a second ceramic green sheet on the green ceramic substrate so as to cover the surface conductors and the main surface of the laminate, the second ceramic green sheet subsequently being integrated with the first ceramic green sheets by cofiring;
(c) laminating a restraint sheet on each of opposite sides of the green ceramic substrate covered with the second ceramic green sheet, so as to restrain the green ceramic substrate together with the second ceramic green sheet, the restraint sheets containing a predominant amount of a sintering-resistant inorganic material, which is not sintered at a sintering temperature at which the green ceramic substrate is sintered;
(d) firing the second ceramic green sheet and the green ceramic substrate under restraint at a temperature at which the second ceramic green sheet and the green ceramic substrate are integrally sintered, whereas the restraint sheets are not sintered, to thereby yield a ceramic substrate restrained by means of the restraint sheets;
and
(e) removing, from the ceramic substrate restrained by means of the restraint sheets, the restraint sheets and a ceramic covering layer which is an upper portion of a ceramic layer formed from the second ceramic green sheet and which covers the surface conductors, to thereby expose the surface conductors, while leaving a lower portion of the ceramic layer formed from the second ceramic green sheet on the ceramic substrate.

3 more elements

A method for producing a ceramic substrate, which comprises:

(a) fabricating a green ceramic substrate comprising a laminate of first ceramic green sheets and conductor layers, and surface conductors formed on a main surface of the laminate;
(b) applying a ceramic paste to a surface of the green ceramic substrate on which surface conductors are formed to thereby form a paste coating layer and then laminating a second ceramic green sheet on the formed paste coating layer so as to cover the surface conductors and the main surface of the laminate with a green ceramic covering layer including the paste coating layer and the second ceramic green sheet, the ceramic paste subsequently being integrated with the green ceramic substrate by cofiring and the second ceramic green sheet subsequently being integrated with the paste coating layer by cofiring;
(c) laminating a restraint sheet on each of opposite sides of the green ceramic substrate covered with the green ceramic covering layer, so as to restrain the green ceramic substrate together with the green ceramic covering layer, the restraint sheets containing a predominant amount of a sintering-resistant inorganic material, which is not sintered at a sintering temperature at which the green ceramic substrate is sintered;
(d) firing the green ceramic covering layer and the green ceramic substrate under restraint at a temperature at which the green ceramic covering layer and the green ceramic substrate are integrally sintered, whereas the restraint sheets are not sintered, to thereby yield a ceramic substrate restrained by means of the restraint sheets;
and
(e) removing, from the ceramic substrate restrained by means of the restraint sheets, the restraint sheets and a ceramic covering layer which is an upper portion of a ceramic layer formed from the green ceramic covering layer and which covers the surface conductors, to thereby expose the surface conductors.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/935,164Filed 8 Sep 2004
Priority: JP 2003-3167899 Sep 2003
Published: US 2005/0051253 A110 Mar 2005
Granted: 12 Sep 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification32 codes

B32B 18/00
Layered products essentially comprising ceramics
C03C 14/004
Glass compositions containing a non-glass component, e.g. compositions containing fibres, filaments, whiskers, platelets, or the like, dispersed…:…
H01G 4/30
Fixed capacitors; Processes of their manufacture: stacked capacitors
H05K 3/246
Reinforcing conductive patterns made by printing techniques or by other techniques for applying conductive pastes, inks or powders; Reinforcing…:…