Copper paste and wiring board using the same

A wiring board obtained by filling a copper paste in a via hole formed on a ceramic green sheet and firing it to form an insulating layer and a via conductor, the copper paste comprising a copper powder, an organic vehicle and a ceramic particle having an average particle size of 50 nm or less, wherein the copper paste comprises from 6 to 20 parts by mass of the organic vehicle per 100 parts by mass of the copper powder.

A wiring board obtained by filling a copper paste in a via hole formed on a ceramic green sheet and firing it to form an insulating layer and a via conductor, the copper paste comprising a copper powder, an organic vehicle and an Fe2O3 particle in an amount of from 0.1 to 5.0 parts by mass, wherein the copper paste comprises from 6 to 20 parts by mass of the organic vehicle per 100 parts by mass of the copper powder.

A wiring board obtained by filling a copper paste in a via hole formed in a ceramic green sheet and firing to form an insulating layer and a via conductor, said via conductor having inside thereof an inorganic matter having a size of 10 μm or less after firing, said size being a long diameter thereof where the inorganic matter has a spherical or near spherical shape or an equivalent diameter where the inorganic matter has an amorphous shape.

A wiring board obtained by filling a copper paste in a via hole formed in a ceramic green sheet and firing to form an insulating layer and a via conductor, said via conductor having dispersed therein an inorganic matter, wherein in a cross section in a thickness direction of the wiring board, a total area of the inorganic matter having a particle size of 2 μm or more after firing is 10% or less of the sectional area of the via conductor.

A wiring board obtained by filling a copper paste in a via hole formed in a ceramic green sheet and firing to form an insulating layer and a via conductor, said via conductor having dispersed therein an inorganic matter, wherein in a cross section in a thickness direction of the wiring board, a total area of the inorganic matter having a particle size of 5 μm or more after firing is 5% or less of the sectional area of the via conductor.

A wiring board obtained by filling a copper paste in a via hole formed in a ceramic green sheet and firing to form an insulating layer and a via conductor, said via conductor having dispersed therein an inorganic matter, wherein in a-cross section in a thickness direction of the wiring board, a total area of the inorganic matter having a particle size of 10 μm or more after firing is 2% or less of the sectional area of the via conductor.

A copper paste comprising a copper powder, an organic vehicle, a ceramic particle having an average particle size of 100 nm or less;

• and an Fe2O3 particle, wherein the copper paste comprises from 6 to 20 parts by mass of the organic vehicle per 100 parts by mass of the copper powder.

A copper paste comprising a copper powder, an organic vehicle and a ceramic particle having an average particle size of 50 nm or less, wherein the copper paste comprises from 6 to 20 parts by mass of the organic vehicle per 100 parts by mass of the copper powder.

A copper paste comprising a copper powder, an organic vehicle and an Fe2O3 particle in an amount of from 0.1 to 5.0 parts by mass, wherein the copper paste comprises from 6 to 20 parts by mass of the organic vehicle per 100 parts by mass of the copper powder.

A copper paste comprising a copper powder, an organic vehicle, a ceramic particle having an average particle size of 100 nm or less and an Fe2O3 particle, wherein the copper paste has a viscosity of 5,000 to 1,000,000 poises.

A copper paste comprising a copper powder, an organic vehicle and a ceramic particle having an average particle size of 50 nm or less, wherein the copper paste has a viscosity of 5,000 to 1,000,000 poises.

A copper paste comprising a copper powder, an organic vehicle and an Fe2O3 particle in an amount of from 0.1 to 5.0 parts by mass, wherein the copper paste has a viscosity of 5,000 to 1,000,000 poises.