PCB wiring in the whole PCB design is very important, how to do fast and efficient wiring, and make your PCB wiring look high, it is worth studying and learning. Sorted out 7 aspects that need to pay attention to in PCB wiring, come to check and fill the gaps!

How to make your PCB design more efficient

1. Common ground processing of digital circuit and analog circuit

Many PCBS are no longer single-function circuits (digital or analog), but are a mix of digital and analog circuits. Therefore, when wiring, we need to consider the interference between them, especially the noise interference on the ground line. The sensitivity of the high frequency digital circuits, analog circuits, the signal wire, high-frequency signal lines as far as possible away from the sensitive analog devices, for the ground, moving the PCB to the outside world is only one node, so must be within the PCB processing, mold has problem, and inside the plate to digital and analog is actually are divided between them, Only in the PCB and external connection interface (such as plug, etc.). There is a bit of a short connection between the digital ground and the analog ground. Note that there is only one connection point. There are also incongruent ones on the PCB, depending on the system design.

2. The signal line is laid on the electric (ground) layer

In the multi-layer PCB wiring, because there is no finished line left in the signal line layer, and then add layers will cause waste will also increase the production of a certain amount of work, the cost also increased accordingly, in order to solve this contradiction, you can consider wiring in the electrical (ground) layer. The power zone should be considered first, and the formation second. Because it’s better to keep the formation intact.

3. Processing of connecting legs in large area conductor

In the large area of grounding (electricity), the legs of common components are connected with it. The processing of the connecting legs needs to be considered comprehensively. In terms of electrical performance, the pads of component legs are fully connected with the copper surface, but there are some hidden dangers for the welding assembly of components, such as: (1) the welding needs a high power heater. (2) Easy to cause virtual solder joints. Therefore, taking into account the electrical performance and process needs, make a cross welding pad, called heat shield, commonly known as Thermal, so that the possibility of virtual welding spot due to excessive heat dissipation of the section during welding can be greatly reduced. The electrical (ground) leg of the multilayer is treated the same.

4. The role of network system in wiring

In many CAD systems, wiring is determined by the network system. The grid is too dense, the path is increased, but the step is too small, the data volume of the graph field is too large, which will inevitably have higher requirements for the storage space of the equipment, but also has a great impact on the computing speed of computer electronic products. Some paths are invalid, such as those occupied by the pads of component legs or by mounting holes, setting holes, etc. Too sparse grid and too few paths have a great influence on the distribution rate. Therefore, there should be a reasonable grid system to support the wiring. The legs of standard components are 0.1 inch (2.54mm) apart, so the base of grid systems is usually 0.1 inch (2.54mm) or integral multiples of less than 0.1 inch (e.g. 0.05 inch, 0.025 inch, 0.02 inch, etc.).