| 摘要 |
PURPOSE:To obtain a low-cost and high-reliability connection material by a method wherein a heat-resisting resin film whose coefficient of thermal expansion is identical to that of a metal is used as a long and flexible substrate and this film is bonded directly to a sheet of metal foil such as copper coil without using an adhesive. CONSTITUTION:A flexible substrate to which a heat-resisting resin film 7 whose coefficient of thermal expansion is identical to that of a sheet of metal foil 6 has been bonded directly without making a hole in advance and without using an adhesive is used as a base material; a circuit in processed by using an ordinary technique for a printed-circuit board; a number of lead wires 6' are formed. During this process, the heat-resisting resin film 7 on the rear is left is a back-reinforcing material of the lead wires without making a hole even after the circuit has been formed. The surface of the lead wires is plated 8 by using tin, solder or the like; the plated part is aligned with a connection bump 9 of an IC chip 10; the connection bump 9 is electrically connected from the side of the heat-resisting resin film 7. By this setup, a process to make a hole and a back-masking process are not required; a lowcost connection is realized. |
