Multilayer wiring board and method of manufacturing the same

Claim 1

A multilayer wiring board comprising an insulating substrate, at least two conductor layers of predetermined patterns which are provided on said insulating substrate, and an insulator film which is interposed between said conductor layers, said insulating substrate and said insulator film being made of an insulating material which is produced by sintering an oxide mixture of i) 70 - 50 wt.% of glass material powder having a composition of 20 - 30 wt.% of SiO 2 , 18 - 25 wt.% of Al 2 O 3 , 18 - 20 wt. % of B 2 0 3 , 1 - 6 wt.% of ZnO, 18 - 28 wt.% of BaO, and 1 - 8 wt.% of MgO and Cao in total, and ii) 30 - 50 wt.% of inorganic oxide powder composed of Al 2 O 3 powder and ZrSiO 4 powder.

Claim 11

A method of manufacturing a multilayer wiring board comprising: i) the step of mixing 70 - 50 wt..% of glass material powder and 30 - 50 wt.% of inorganic oxide powder to prepare an oxide mixture, said glass material powder having a composition of 20 - 30 wt.% of SiO 2 , 18 - 25 wt.% of A1203, 18 - 20 wt.% of B 2 0 3 , 1 - 6 wt.% of ZnO, 18 - 28 wt.% of BaO, and 1 - 8 wt.% of MgO and Cao in total, and having a mean particle size of 2.0 - 4.0 µm, said inorganic oxide powder consisting essentially of an Al 2 O 3 powder having a mean particle size of 2.0 - 4.0 µm and a ZrSi0 4 powder having a mean particle size of 2.0 - 4.0 µm, ii) the step of mixing a polymer, a volatile solvent and a plasticizer into said oxide mixture, to form a slurry and drying said slurry to form a flat green sheet, iii) the step of mixing a polymer and a volatile solvent into said oxide mixture, to produce an insulator paste, iv) the step of mixing a polymer and a volatile solvent into a metal powder mixture, to produce a conductor paste, said metal powder mixture consisting essentially of 80 - 75 wt.% of Ag powder having a mean particle size of 0.3 - 0.7 µm and 20 - 25 wt.% of Pd powder having a mean particle size of 0.2 - 0.5 µm, and v) the step of alternately printing said conductor paste and said insulator paste on said green sheet in multilayered fashion, and thereafter sintering the multilayer structure unitarily at 800 - 900 °C.

Claim 12

A method of manufacturing a multilayer wiring board comprising: i) the step of mixing 70 - 50 wt..% of glass material powder and 30 - 50 wt.% of inorganic oxide powder to prepare an oxide mixture, said glass material powder having a composition of 20 - 30 wt.% of SiO 2 , 18 - 25 wt.% of A1203, 18 - 20 wt.% of B 2 0 3 , 1 - 6 wt.% of ZnO, 18 - 28 wt.% of BaO, and 1 - 8 wt.% of MgO and Cao in total, and having a mean particle size of 2.0 - 4.0 µm, said inorganic oxide powder consisting essentially of an Al 2 O 3 powder having a mean particle size of 2.0 - 4.0 µm and a ZrSi0 4 powder having a mean particle size of 2.0 - 4.0 µm, ii) the step of mixing a polymer, a volatile solvent and a plasticizer into said oxide mixture, to form a slurry and drying said slurry to form a flat green sheet, iii) the step of mixing a polymer and a volatile solvent into said oxide mixture, to produce an insulator paste, iv) the step of mixing a polymer and a volatile solvent into a metal powder mixture, to produce a conductor paste, said metal powder mixture consisting essentially of 80 - 75 wt.% of Ag powder having a mean particle size of 0.3 - 0.7 µm and 20 - 25 wt.% of Pd powder having a mean particle size of 0.2 - 0.5 µm, and v) the step of alternately printing said conductor paste and said insulator paste on said green sheet in multilayered fashion, and thereafter sintering the multilayer structure unitarily at 800 - 900 °C.