| 摘要 |
PROBLEM TO BE SOLVED: To provide a conductive paste that does not contain harmful lead, may be burnt at medium temperatures, has an excellent conductivity, and may form a thick conductive film with a sufficient adhesive strength to a substrate, and provide a printed circuit board employing it. SOLUTION: A conductive paste is composed of at least one kind of powder selected from one copper, copper alloy a mixture containing copper, glass frit, and organic vehicle. The glass powder constituting the glass frit has a composition expressed by the following formula: xBi2O3-yB2O3-zSiO2 (in this case, the unit of x, y, z is mol%), wherein the proportion of x, y and z is within the region enclosed by four points A (15, 35, 50), B (25, 60, 15), C (45, 40, 15), and D (45, 20, 35) in a ternary composition diagram as shown in Fig.1, and the average particle size is n the range of 0.1 to 1.0μm. |
