Practical Tips | 12 Details That Cannot Be Ignored in PCB Layout

If adjacent pads need to be connected, first make sure to connect them on the outside to prevent them from being connected together and causing bridges, and pay attention to the width of the copper wire at this time.

If the pad falls on the through-hole area, the method on the right should be used to connect the pad and the through-hole, and whether to connect one wire or four wires should be determined based on the current size.

If you take the method on the left, it will be difficult to weld or repair and disassemble components, because the temperature is dispersed through the copper, resulting in poor soldering.

If the wire is smaller than the pad of the through-hole device, you need to add a teardrop connection as shown on the right side of the picture above. Adding a teardrop connection has the following advantages:

1. Avoid reflection caused by a sudden decrease in signal line width, so that the connection between the trace and the component pad can be smoothly transitioned.

2. Solved the problem that the connection between the pad and the trace is easily broken by impact.

3. Setting teardrops can also make the PCB circuit board look more beautiful.

The lead width on both sides of the component pad should be consistent

Be careful to keep the pads of unused pins and ground them correctly. For example, in the above picture, two pins of a chip are not used, but the physical pins of the chip exist. If the two pins are left floating like on the right side of the above picture, it is easy to cause interference. If pads are added and then grounded to shield, interference can be avoided.

Note that it is best not to drill through holes on the pads, as this can easily cause tin leakage and poor soldering.

It should be noted that the leads or components cannot be too close to the edge of the board, especially single-sided boards. Generally, single-sided boards are paper boards, which are easy to break after being stressed. If wires are connected or components are placed on the edge, it will be affected.

First of all, we need to consider whether the ambient temperature of the electrolytic capacitor meets the requirements. Secondly, we need to keep the capacitor as far away from the heating area as possible to prevent the liquid electrolyte inside the electrolytic capacitor from being dried out.