For a long time, PCB buyers have always had doubts about the color of PCB, and they don’t know what color PCB board is of high quality. How does the color of the PCB affect its performance?
First, 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 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 board. However, in the process of washing PCB, black is the most likely to cause chromatic aberration. If the raw materials and manufacturing processes used by the PCB factory are slightly off, the PCB defect rate will increase due to the chromatic aberration. This directly leads to an increase in production costs.
In fact, the raw materials of PCB are seen 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 substrate.
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 stages. Generally, if there is no brand with profound RD (R&D) designers and a strong maintenance team, black PCBs will not be easily used. of. It can be said that the use of black PCB is an expression of a brand’s confidence in the RD design and post-maintenance team. From the 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 board designs for their products. Therefore, most products with large shipments in the market that year used red PCBs, green PCBs or blue PCBs. Black PCBs can only be seen on mid-to-high-end or top-level flagship products, so customers should not think of black anymore. PCB is better than green PCB.
About the color selection of circuit board proofing
1. Green ink is by far the most widely used, the longest in history, and the cheapest in the current market, so green is used by a large number of manufacturers as the main color of their products.
2. Under normal circumstances, the entire PCB board product has to go through the board making and SMT process during the production process. When making the board, there are several processes that must go through the yellow light room, because the green is in the yellow The effect of the light room must be better with other colors, but this is not the main reason. When soldering components in SMT, the PCB has to go through the process of solder paste and post film and the final AOI calibration light. These processes all need to be optically positioned and calibrated. The green background color is better for the recognition of the instrument.
3. Common PCB colors are red, yellow, green, blue and black. However, due to problems such as the production process, the quality inspection process of many lines still has to rely on the naked eye observation and identification of the workers (of course, most of the current flying probe testing technology is used). In the case of strong light, the eyes kept staring at the board. This is a very old Liu’s work process. Relatively speaking, green is the least harmful to the eyes, so most manufacturers in the market currently use green PCBs.
4. The principle of blue and black is that they are doped with cobalt and carbon lamp elements respectively, and have certain electrical conductivity. Short circuit problems are likely to occur when power is on, and green PCBs are relatively environmentally friendly, in high temperature environments When used in medium, generally no toxic gas will be released.
There are also a small number of manufacturers in the market that use black PCB boards. The main reason for this is that the editor of Jiepei https://www.jiepei.com/g34 believes that there are two reasons: one, it looks high-end; two, black It is not easy to see the wiring on the board, which brings a certain degree of difficulty to the copy board. What I learned is that most of the Android embedded boards now use black PCBs.