Issues that need attention in PCB circuit board design

In the production of circuit boards, we often encounter a lot of products that fail to meet the expected design due to design reasons. As a circuit board manufacturer, the film is designed by customers and printed on the circuit board. If it is a problem with the drawing, the circuit board manufacturer is also powerless.

Today, I will give examples of the problems we often encounter in production. How designers should design. Here are some examples. The most prone problems, but there are also some minor problems, but the design is not so concerned, resulting in problems .

1. The problem of golden hands opening windows: usually our golden fingers are used to open windows. If you want to open the window, you must design the drawing to open the window when designing, not to cover the oil. Because not all engineering personnel will confirm with you when the circuit board manufacturer produces, it is processed according to the data or opening the window.

2. Via-hole cover oil problem: I often encounter customer complaints. My board needs to be covered with oil. Why is the window open? We checked the design drawings. As a result, the drawings were window-opened. When designing, it must be designed to be covered with oil, and the window cannot be opened. If you did not notice that you opened the window, then the finished product must also be windowed.

For those that must open the window as a test point, please be careful not to cover the oil.

3. Character problem: We often encounter the problem that the characters are too small to be printed. If they are too small, they will be printed as one piece and cannot be seen clearly. The minimum character size required by the circuit board manufacturer is 0.8*1.5MM. The minimum size is this size, and it will be unclear if it is smaller than it. The other is that the characters cannot be placed on the pad, and all the characters on the pad need to be removed.

4. Via-to-line, via-to-hole problem: In the design, there must be at least 0.2MM spacing between vias and lines, and 0.3MM spacing between holes and holes. In the production process, vias, pads, and lines are all Need compensation. The original drawings need to be spaced to facilitate compensation in the processing of the production drawings. If the production drawings are not compensated, the finished product will be smaller than the design after etching.

5. Distance from hole and line to board edge: It is often encountered that some design holes and lines are next to the contour line. Usually the distance from the line to the shape should be kept above 0.5mm to ensure that the line has position compensation and the shape will not reach the line. The hole to the profile line is above 0.5mm, and position compensation is reserved. Less than 0.5MM will cause the edge of the finished product

Expose copper, if the edge of the board does not accept exposed copper, it needs to be processed by copper extraction, and the pad will be slightly smaller after copper extraction.