Method of circuit connection across both surfaces of substrate

摘要

PCT No. PCT/JP83/00417 Sec. 371 Date Jul. 26, 1984 Sec. 102(e) Date Jul. 26, 1984 PCT Filed Nov. 22, 1983 PCT Pub. No. WO84/02248 PCT Pub. Date Jun. 7, 1984.According to this invention, an electrically conducting wire provided with a solder ball is inserted through throughholes provided around the perimeters thereof with electrically conductive members such as copper foils which form printed wiring on both surfaces of an insulating substrate. One of the conductive members and the conducting wire are soldered by dipping or flow-soldering, thereby making a circuit connection across both surfaces of the substrate by causing melting of the solder ball on the conducting wire on the substrate surface not soldered.