摘要 |
PURPOSE:To prevent a metal piece from dropping in the manufacturing steps by forming the first surface treating layer by gold or silver plating on element placing portion and inner end side lead portion, and forming the second surface treating layer by tin or solder plating on the outer end side lead portion. CONSTITUTION:Silver or gold plating is treated on inner end side leads 1 and element placing portion 2. The outer frame 13 of a lead frame and the outer side 14 of the lead frame are not surface treated, but a lead frame material 8 is exposed. Silver or solder plating is executed on the outer end side lead 5 which includes a tie bar. In the drawings, numeral 14 designates the outside end of the lead frame, and numeral 9 designates the second treating layer by silver or solder plating to cover the material 8. The material 8 is exposed at the outside end 14 of the lead frame and the vicinity, and metal not is separated nor dropped by friction of handling at the end of the lead frame in the manufacturing steps. |