Viewpoint 1, generally speaking, the board grade product of whole electronic must pass through the plate making and the SMT process, there are several working procedures in the board making process to pass through the lithography area (because photo resist is most insensitive to the yellow light, and are generally carried out under the yellow light, lithography area is often called yellow room.), the green is better in the yellow room visual effect, but this is not the main.
During soldering, tinning and SMT and last AOI check are required. These processes all require optical positioning calibration. The green background colors have better recognition effect on the instrument.
Viewpoint 2, common colors have red, yellow, green, blue and black. Due to process problems, many lines of inspection are still relying on the worker’s eyes (of course, most of them use flying probes for testing now). This is a very tiring job, green is relatively least to hurt the eyes. So most use green.
Viewpoint 3, blue and black is because they are respectively doped with cobalt and carbon, which has certain conductivity, so there is a risk of short circuit. Green PCB is more environmentally friendly and will not release toxic gases when used under high temperature environment.
Viewpoint 4, from about 2007, people began to pay attention to the color of the PCB board, mainly because the high-end board of Asustek MSI these first-tier manufacturers have adopted a black PCB board color design, so people slowly think that PCB color Black is definitely high-end. Since then, more and more manufacturers have begun to use black PCB coating – it can be said that a strange reason has caused such an inexplicable phenomenon. No one has ever said that the PCB color is black to represent the quality of the board. It is entirely due to the misleading product identification caused by the first-line brands using black to identify product positioning. It is true that black PCBs are indeed capable of demonstrating their own technological capabilities, because black PCBs are the least easy to see lines. Therefore, whether design or after-sales services will be subject to unprecedented cost pressures, while technically strong board manufacturers use black color tone PCBs not because of the black can enhance the performance of the board, from a rational analysis point of view also know that color alone can not improve the performance of the board.
Viewpoint 5, no reason, but it has been used.
