Laser Repair and Rework of Bare and Assembled Printed Circuit Boards

The laser as a tool for the rework and repair of printed circuit boards

Solder resist and polyimide cover foil material on copper base material can be sufficiently removed using the laser to produce clean copper surfaces. As a result the laser can be used for the rework or repair of assembled and bare printed circuit boards. PCBs that would otherwise be scrapped due to design or process errors or design amendments can be reworked or repaired fast and cost-effectively using the laser. Furthermore, yields can be improved and the time to get the product to the customer can be reduced in many cases, especially in the case of expensive multi layer boards.

Repair and rework of PCBs comprises the removal of solder resist or cover foil material:

• to subsequently open pads which have been covered by mistake
• to create new pads for the subsequent assembly with SMD-components
• to open larger conductive areas
• to clean through holes

Furthermore, circuit tracks can be opened by removing the copper itself.

The Q-switched UV-laser used is characterized by extremely high-pulse peak powers due to very short pulse lengths making it possible to directly evaporize the dielectric without damaging the copper underneath. As a result clean copper surfaces are produced, which are suited for the rework without the necessity of additional cleaning processes.


Read further under Advantages Laser Repair