First of all, as a printed circuit board, PCB mainly provides interconnection between electronic components. There is no direct relationship between color and performance, and the difference in pigments does not affect the electrical properties. 

The performance of the PCB board is determined by factors such as the material used (high Q value), wiring design, and several layers of the board. However, in the process of washing the PCB, black is the most likely to cause color differences. If the raw materials and manufacturing processes used by the PCB factory are slightly different, the PCB defect rate will increase due to the color difference. This directly leads to an increase in production costs.

In fact, the raw materials of PCB are everywhere in our daily life, that is, glass fiber and resin. The glass fiber and resin are combined and hardened to become a heat-insulating, insulating, and not easy to bend board, which is the PCB substrate. Of course, a PCB substrate made of glass fiber and resin alone cannot conduct signals. Therefore, on the PCB substrate, the manufacturer will cover a layer of copper on the surface, so the PCB substrate can also be called a copper-clad printed circuit board.

As the circuit traces of the black PCB are difficult to identify, it will increase the difficulty of repair and debugging in the R&D and after-sales phases. Generally, if there is no brand with profound RD (R&D) designers and a strong maintenance team, black PCBs will not be easily used. It can be said that the use of black PCB is a brand's confidence in the RD design and post-maintenance team. On the other side, it is also a manifestation of the manufacturer's confidence in its own strength.

Based on the above reasons, major manufacturers will carefully consider when choosing PCB designs for their products. Therefore, most of the products with large shipments in the market that year used red PCB, green PCB, or blue PCB versions. Black PCBs can only be seen on mid-to-high-end or top flagship products, so don’t believe black PCBs are better than green.