Presumably, the PCB circuit board laminate problem has puzzled everyone for a long time. After discussing with the engineer for a long time, I was able to write this article. Here, the editor of the board factory exemplifies some common problems of pcb laminates and related solutions. If you encounter common problems such as pcb board laminates, you should formulate a standard, and you can find the right remedy for such problems in the future.

　　1. The flow direction should be scientific and reasonable

　　There are many aspects involved in this, such as high voltage/low voltage, input/output, strong/weak data signal, high frequency/low frequency and so on. The most reasonable direction of their flow should be linear and should not merge with each other. The principle to follow is to eliminate mutual interference. A more suitable flow direction is a straight line, but it is difficult to achieve. The most inappropriate flow direction is the loop, thankfully there is also the operation of isolation. If it is specifically aimed at DC, the design requirements of low-voltage PCB circuit boards can be lower. So the so-called "scientifically reasonable" is only relative.

　　2. Reasonable layout of power filter/decoupling capacitors

　　The layout of the PCB circuit board is critical to the appearance and performance of the entire circuit board. Only some of the power supply filter/decoupling capacitors are drawn in the schematic, but there is no clear indication of where they should be connected. I think those capacitors are set for switching devices or other components that need filtering/decoupling. The position of the capacitors should be close to those components, and the effect will not be found if they are separated by a long distance. When we rationalize the power supply filtering/decoupling capacitors, the common problems of grounding points don't seem to be prominent anymore. Everyone can try it out!

　　3. The grounding point is better

　　I don’t need to say more about the importance of choosing a grounding point. It has been discussed by countless professionals, usually requiring standard co-location. For example, the multiple ground wires of the forward amplifier should be combined and then connected to the trunk ground and so on. But in real life, it is difficult to do it completely due to various types of constraints. But we cannot ignore it and should do our best to follow the principles. This common problem is very flexible in practice, and different people have different solutions. If it can be expressed specifically for a specific pcb circuit board, it is very easy to understand.

　　4. Reasonable selection of lines

　　It is called a circuit board. Of course, the lines are very important! If conditions permit, try to make the lines wider. High-voltage and high-frequency lines should be smoother without sharp chamfers. There should also be no 90° in turns, and the ground wire should be as wide as possible. To solve the problem of the grounding point, a better way is to pour a large area of copper. If there is a better way, please leave a message in the comment area, and I will learn more.

　　The problem of PCB circuit board is inseparable from design and circuit board processing. For example, problems that sometimes appear in post-production are likely to be caused by the design of the PCB. For example, too many wire holes, substandard copper sinking process, etc., can easily hide many hidden safety hazards. From the above problems, we can draw a conclusion that the wiring holes should be reduced as much as possible in the PCB circuit board design concept. If the number of parallel lines in the same direction is large and the density is high, they will be connected together during welding. Therefore, the welding level during production determines the size of the linear density. If the spacing of the solder joints is too small, the difficulty of manual welding will increase a lot. At this time, the only way to solve the welding quality is to reduce the work efficiency. Otherwise, there will be more and more problems in the future, and it will become more and more difficult to deal with. The skill and efficiency of the welder determines the narrowest pitch of the solder joints.

　　When the size of the pad or via hole is too small, it becomes more difficult for manual drilling. When the size of the pad does not match the size of the drill hole, it is a bolt from the blue for CNC drilling, and the pad is prone to a C shape. If the situation is serious, the pads will be drilled off. If the wires are too thin, and there is no copper in large unrouted areas, there is a high probability of uneven corrosion. That is to say, when the unwiring area is etched, it is very likely that the thin wire will be excessively etched. Sometimes it seems that the line is broken, but it is not broken, and if it is more serious, the line will be broken. Therefore, setting copper is not just to expand the ground area. The above is purely personal opinion, if you have anything you want to add, you can leave a message below the comments, and we can make progress together!

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