Many engineers do not want to see a short circuit in the PCBA. How to do PCB short circuit? Join us today to find out why the short circuit is happening. If there is a short circuit, how do we troubleshoot it?

There are usually two kinds of short circuit. 1. PCB circuit board has reached a certain service life. The second situation is the PCB circuit board production inspection work is not in place. However, these small errors in production, but to the entire PCB circuit board caused great harm, is likely to lead to scrap. So how do we check and prevent short circuits on circuit boards?

The first:

Open the PCB diagram on your computer and light the short-circuited net to see where it is closest and most likely to be connected. Pay special attention to the short circuit inside the IC.

The second:

Use short circuit positioning analyzer, such as: Singapore PROTEQ CB2000 short circuit tracker, Hong Kong Ling Zhi technology QT50 short circuit tracker, POLAR ToneOhm950 multi-layer board short circuit detector, etc.

The third:

Be careful when welding small surface mount capacitors, especially power filter capacitors (103 or 104), which are large in number and easy to cause short circuit between the power supply and the ground. Of course, sometimes the capacitor itself will short out out of luck, so the best thing to do is to test the capacitor before welding.

The fourth

If you are welding by hand, form good habits. First, visually check the PCB board before welding, and use a multimeter to check whether the key circuit (especially the power supply and ground) is short circuit; Secondly, after each chip is welded, use a multimeter to measure whether the power supply and ground are short-circuited; In addition, do not throw the soldering iron at will when welding. If solder spills onto the foot of the chip (especially surface mount elements), it can be difficult to find it.

Fifth:

If there is a BGA chip, because all solder joints are covered by the chip, can not be seen, and is a multi-layer board (more than 4 layers), it is best to separate the design of each chip power supply grading, and connected with magnetic beads or 0 OHresistor, so that when the power supply and ground short circuit, magnetic beads detection disconnected, easy to locate a chip. Because welding BGA is difficult, if the machine is not automatic welding, it will short circuit the two welding balls of the adjacent power supply and ground.

Sixth:

If you find a short circuit, take a board and cut out the circuit (especially suitable for single/double layer boards). After cutting, each part of the functional block is electrified and eliminated part by part.