Method for reducing gold salt waste by electroless nickel immersion gold treatment of PCB

Abstract

The invention relates to a method for reducing the waste of gold salt in a nickel-gold PCB, comprising the following steps: 1) removing or reducing the width of the choke strips near the edge of the inner core board when making the PCB, and then presetting the Reserve a certain width of copper-free area for edge milling; 2) Use a milling cutter to perform edge milling in the copper-free area reserved on the edge of the board to avoid exposed copper on the edge of the board; 3) Treat the surface of the PCB with nickel-gold, at this time , Since there is no exposed copper on the edge of the board, it can prevent gold from attaching to the edge of the board and reduce the waste of gold salt. This method does not require glued paper when nickel-gold is deposited, so the processing cost can be reduced, and the quality of PCB products will not be affected by the reduction of the board edge baffle strips.

Description

technical field [0001] The invention belongs to the field of PCB printed circuit board manufacture, and specifically relates to a method for reducing the waste of gold salt on a nickel-gold PCB. Background technique [0002] At present, PCBs whose surface is nickel-gold have a lot of exposed copper on the edge of the working board. When chemical gold is used, gold will also be attached to the edge of the board, resulting in a lot of waste of gold salt. The exposed copper is mainly exposed copper on the choke strip of the inner core board. After lamination, the milling edge is exposed, and it cannot be etched away even if the negative film process is used. The problem of exposed copper on the edge of the board is currently solved by wrapping the edge of the board, but the machine wrapping requires special equipment, and the manual wrapping requires a lot of manpower and tools, and the cost of the tape increases the processing cost by 20%. Contents of the invention [0003]...

AI Technical Summary

Problems solved by technology

[0002] At present, the surface treatment of the PCB is nickel-gold, and there will be a lot of exposed copper on the edge of the working board. When doing chemical gold, the edge of the board will also be attached to gold, resulting in a lot of waste of gold salt.

The exposed copper is mainly exposed copper on the choke strip of the inner core board. After pressing, the milling edge is exposed, and it cannot be etched away even if the negative film process is used.

The problem of exposed copper on the edge of the board is currently solved by wrapping the edge of the board, but the machine wrapping requires special equipment, and the manual wrapping requires a lot of manpower and tools, and the cost of the tape increases the processing cost by 20%.