| 摘要 |
PURPOSE:To make possible the direct wire bonding and suppress the abrasion of contact land by executing soft gold plating to the element connecting part on the nickel plating and hard gold plating in the plating structure in an external connecting terminal circuit. CONSTITUTION:Wiring is formed by etching the laminated board made of the copper-clad glass epoxy, nickel plating is conducted thereto and hard gold plating is carried out to the entire part of the printed circuit board 31. Next, the contact land 32 is partly masked 33 for partial plating and soft gold plating is further conducted to the soft-gold plated wiring layer 34 for wire bonding. Thereafter, the mask 33 is melted and washing is carried out. A printed circuit board 35 can be obtained. Connection of gold wire is possible by the thermal pressure wire bonding in combination with ultrasonic wave and the contact land which may generate mechanical abrasion is subjected to hard gold-plating with less which assures less abrasion. |
