We had issue with one of the rigid-flex design cracking at the joint of Rigid and flex intersection. It is important to note that this is second batch of same PCB and PCB was not cracking in first batch.
So we reached out to manufacturer and asked for root cause.
They said reason incorrect laser parameters of their machine and also said that they will change the PP design from window opening to Slot opening which will eliminate need of laser all together.
My question is what exactly is changing? What does Window or slot opening actually achieve?