| 摘要 |
PURPOSE:To avoid solder attached to the rear surface of a base plate from advancing to the bonding face and pellet-mounting face of a circuit pattern on the front surface side of the base plate so as to ensure wire bonding and mounting of a pellet by moving the base plate through the inside of a furnace while a heat resistant sheet is provided on the front surface side of the base plate. CONSTITUTION:A plurality of holes for fixing leads are punched through a base 4 having a circuit pattern 3 on its surface in which a pellet mounting area 1 and a wire bonding area 2 are formed. A heat resistant sheet 11 is stuck to that surface of the base 4 on which the circuit pattern is formed and metal leads 6 are inserted into the respective lead fixing holes of the base 4 and solder 7 is attached to around each hole 5 from the rear surface of the base plate 4. Thereafter, the base plate 4 is fed into a reflow furnace with the surface of the circuit pattern downward and the solder 7 is melted and fixed and the leads 6 are fixed to the respective lead fixing holes 5 by the solder 7. The solder attached to the rear surface of the base plate 4 is thereby prevented from advancing to the bonding surface and pellet-mounting surface of the front side surface of the circuit pattern 3, whereby wire bonding and mounting of a pellet are ensured. |
