Consumer, military and security products without product part codes make them harder to reverse engineer or hack. The problem is that this is usually done after the PCB assembly otherwise it is difficult to ensure that the board is assembled correctly; but the usual technique of manually grinding the markings off is time consuming and is liable to damage components and stress solder joints.
Escatec has solved this problem by using its existing CO 2 laser marker that was initially installed to change the surface structure of solder resist to give a clear and permanent marking on the surface of PCBs. The marking it produces can be for machine-readable codes as well as text, graphics and logos, which show up as white areas on the PCB.
"We found that using the laser to burn on a 'sea of numbers' pattern on the tops of the components made sure that none of the [manufacturers' original] markings can be read," explained Martin Muendlein, Engineering Manager at Escatec. "There is no damage or stress and the laser is very fast and accurate to within ±0.1mm. Most importantly, it is fully automatic so that we cut out a huge amount of time that was previously spent grinding the markings off and therefore reduce production costs for the customer."