Effect of solder ink color on plate

The color of PCB surface is actually the color of solder resistance. One is to prevent the occurrence of miswelding of components, and the other is to delay the service life of devices to prevent oxidation and corrosion of device lines.

If you know more about the PCB parts of Huawei and ZTE and other large companies, you will find that the color is generally green. This is because the green process is the most mature and simple.

In addition to green, PCB colors can be described as "flashy" : white, yellow, red, blue, matt color, and even chrysanthemum, purple, black, bright green, etc. White exists because it is the necessary color for the production of lamps and lanterns, while other colors are mostly used for labeling products.

During the whole stage from research and development to product landing, according to different uses of PCB board, the experimental board may be purple, the key board may be red, and the board inside the computer will be black, which will be distinguished and marked by color.

The most common type of PCB is green, green board, also known as the green oil, the solder resist ink is the oldest, the most cheap the most popular. Green oil in addition to the mature process, there are many advantages:

In PCB processing, the production of electronic products includes plate making and sheet Posting. During the process, several processes have to go through the yellow light room, and the visual effect of green PCB board in the yellow light room is the best. Secondly, in the SMT patch processing, tin, patch and AOI check these steps, all need optical positioning and calibration, green plate instrument identification is more friendly.

Part of the testing process relies on worker observation (though flying needle testing is now mostly used instead of manual testing), staring at the board constantly under strong light, and the green color is eye-friendly. Green PCB is also relatively environmental protection, after high temperature recycling treatment, will not release toxic gas.

Other PCB colors, like blue and black, are mixed with cobalt and carbon, respectively, because of their weak electrical conductivity, which can pose a short-circuit risk.

Take black board as an example, black board is most likely to cause color difference due to process and raw material problems in the production, resulting in a high PCB defect rate. The wiring of black circuit board is not easy to identify, which will make it more difficult to repair and debug later. Many PCB factories do not use black PCB. Even in the field of military industry and industrial control, the products with high quality requirements also use green PCB substrate.

Next, we talk about the solder ink color on the plate what effect

For the finished product, the influence of different ink on the plate mainly reflected on the appearance, also is very not good problem, such as green including green, shallow green, deep green, matte green wait for the sun, the color is too shallow, is easy to see jack process after the board not good-looking appearance, some manufacturers of printing ink is not good, there is something wrong with the ratio of resin and the dye, there will be a bubble, Slight changes in color can also be detected; For the impact of semi-finished products, is mainly reflected in the production of the degree of difficulty, this problem is a little complicated to explain, different color ink color process is different, there are electrostatic spraying, spraying, screen printing, ink ratio is different, slightly wrong color will be a problem.

Ink color has no effect on PCB board, but the ink thickness has a very large effect on the impedance, especially the water-metal board, which is extremely strict on the control of ink thickness; Red ink, thickness, bubble is easier to control, red ink covered on the line, can cover some defects, the appearance is more beautiful, but the bad thing is that the price is more expensive. When imaging, red and yellow exposure is more stable, white is the most difficult to control.

To sum up, the color has no effect on the performance of the finished board, and the effect on PCB mounting and other links is relatively small. In PCB design, strict control of each link in every detail, is a PCB board to become a good key board. Different color PCB motherboard, mainly for the appearance of the product service, do not suggest that everyone take the color as an important consideration when PCB processing.