Interconnection of Insulated Fine Wire for PCB

Summary High density assembly of PCB(Printed Circuit Board) is essential to small-size electronic devices. This paper reports on the interconnection of insulated fine wires of 20-100 micrometer diameters. Three new techniques are discussed: first, the thermal decomposition of high polymer is evaluated quantitatively; second, conditions for solid-state bonding of copper is studied using recrystallization growth rate equation and temperature simulation by FEM; lastly the current control unit for micro resistance bonding is developed. An interconnection machine has been developed, which decomposes high polymer insulation of wires by a CO 2 laser and bond them without thermal damage of PCB.