The difference between Lidar PCB and millimeter wave radar PCB

Lidar PCB is a radar system that detects the position, velocity, and other characteristic quantities of a target by emitting a laser beam.
What is carbon ink PCB?

Carbon ink PCB, also known as carbon conductive PCB, is a circuit board that is coated with carbon oil on a copper pad, replacing some more common soldering electroplating methods such as electroless nickel immersion gold (ENIG) or lead-free (HASL).