Does each process have its own PCB or there is just one?

To my understanding, each process in the operating system contains its own separate Process Control Block. Can someone explain this to me. Does each process have its own PCB or is there just one PCB that contains all the information for all the processes?

I want to implement a control system I designed for a light electric motorbike. I would like to mount it as professionally as possible on the chassis. It consists of a power system pcb and a SAMC21 development board which I’ll merge later once this all works properly. I have tried screwing it directly on the aluminium chassis but have found that shocks and vibrations from the horn disturbed the system or even destroyed it upon large shocks. Is there a specific way car and motorcycle manufacturers mount their electronics to make their system as robust as possible?