Patent ID: 9402313
Filing Date: 2016-07-26
CPC Classification: H01B,H01L,H05K

Claim Text:
1. A circuit board, comprising: a plurality of circuit parts; a connecting part including conductive material, comprising: a first metal part whose main ingredient is a first metal; a second metal part formed on the first metal part and whose main ingredient is a second metal, the second metal having a melting point lower than a melting point of the first metal, which second metal forms a metallic compound with the first metal; and a third metal part whose main ingredient is a third metal, which third metal makes a eutectic reaction with the second metal; wherein the circuit parts are connected to each other by the connecting part, the first metal is copper (Cu) or a copper (Cu) alloy, the second metal is tin (Sn) or a tin (Sn) alloy, and the third metal is a powder of bismuth (Bi), indium (In) or an alloy whose main ingredient is bismuth (Bi), the eutectic reaction of the second metal and the third metal is made at a temperature equal to or lower than a glass transition temperature of an insulation substrate, and the metallic compound is formed of the first metal and the second metal and a temperature of a melting point of the metallic compound is higher than a heat-resistant temperature of the insulation substrate.