| 摘要 |
<p>Printed circuits are fabricated by a process which employs initial chemical deposition of copper on a predrilled substrate followed by electroplating build-up of conductors to desired pattern. The conductors are then passivated by thinly plating them with a mechanically durable, chemically passive metal. To provide solder compatibility in areas where connections are to be made to the printed circuits, a plating of tin/lead is applied in those areas while masking all other areas to eliminate plating. The remaining exposed copper is then etched away. An insulating solder mask is then applied.</p> |
