Many people identify the quality of PCB according to the color of PCB. In fact, the color of motherboard has little to do with the performance of PCB.
PCB, it’s not that the taller you look, the better you use it.
The color of PCB surface layer is actually the color of solder resist. The solder resist can avoid the wrong soldering of components, and the other is to slow down the service life of components and avoid air oxidation and corrosion of components.
If you master the PCB parts of Huawei mobile phones, zte ZTE and other large and medium-sized enterprises, you can find that the color is generally all green. This is because the green processing technology is the most perfect and simple.
Apart from green, the color of PCB can be said to be “fancy”: white, light yellow, red, dark blue, sub-light color, and even chrysanthemum, blue-purple, black, bright green, etc. White exists because it is the dye that must be used to make lighting products, while the application of other colors is vacant so as to mark the goods. From product research and development of enterprises to floor-mounted products, according to the different main uses of PCB, the test board may be blue and purple, the most important board also has red, and the internal parts of electronic computers will be marked in black, according to different colors.
The most common pcb board is green green board, also called green oil, and its solder resist ink is the oldest, most cost-effective and most popular. Green oil has many advantages besides perfect processing technology:
In pcb production and processing, the manufacturing of electronic equipment includes plate-making process and its pasting. During this period, several technological processes have to go through the white room, and the visual impact of green PCB in the white room is the best; Secondly, in SMT chip production and processing, the process of soldering, chip mounting and AOI calibration must be precisely positioned and corrected by electronic optics, and the identification of green bottom plate instruments and equipment is more friendly.
Part of the inspection process depends on the staff’s observation (but now most of them use flying needle inspection instead of manual service), and they constantly stare at the board under the strong light. Green is friendly to both eyes. The green PCB is also more environmentally friendly, and it is not easy to release harmful gases when it is bought and solved at high temperature.
Other PCB colors, such as dark blue and black, are doped with cobalt and carbon respectively, so they have the risk of short-circuit fault because of their weak conductivity.
It is too deep, which usually increases the difficulty coefficient of motherboard inspection and maintenance. According to the analysis of the characteristics of black board, it is very easy for black board to have color cast due to difficulties in processing technology and raw materials, resulting in a high unqualified rate of PCB. The wiring of the black PCB is not easy to identify, which will enlarge the difficulty coefficient for the middle and late maintenance and debugging. Many PCB processing plants do not apply the black PCB. Even in military and industrial automation industries, green PCB-based steel plates are used for goods with very high quality requirements.
Next, let’s talk about the harm of solder resist ink color to the board.
As far as finished products are concerned, the harm of different inks to the board is mainly reflected in the appearance, that is, the problem of how to look at it. For example, the green color includes sunlight green, light green, dark green, matte green, etc., and the color is light, so it is very easy to see that the appearance of the board after the hole-plugging process is not good. Some manufacturers’ inks are not very good, epoxy resin and dyes are not well prepared, which may lead to such problems as bubbles, and light color changes can also be found. Aiming at the harm of semi-finished products processing, the key is reflected in the difficulty coefficient level of manufacturing. This problem is a bit complicated to express. Different colors of ink have different coloring processing techniques, such as electrostatic powder spraying, spray painting, ink printing, and ink preparation. Slight errors and omissions in color are all difficult problems.
Although the color of ink has no harm to PCB, the thickness of ink does great harm to the characteristic impedance, especially for water-gold parts, whose manipulation of the thickness of ink is extremely strict. The red ink is very easy to manipulate because of its thickness and bubbles. The red ink covers the top of the route, which can cover some defects. It looks better in appearance, but the bad thing is that it is more expensive. When developing, red and light yellow are exposed more stably, while white is the least easy to manipulate.
Generally speaking, the color has no harm to the characteristics of the finished board, and the harm to PCB mounting and other stages is relatively small; In PCB design, it is important to strictly control every key point in every stage to turn a PCB into a good one. PCB motherboards with different colors are the key to serving the products with all colors and flavors. It is not recommended that everyone take color as the key factor in PCB production and processing.
Therefore, the color of PCB has nothing to do with whether the finished PCB works well or not.
