One of the most problems encountered in the maintenance process of electronic products in the circuit board manufacturers is a short circuit, short circuit on the PCBA board caused considerable harm, as small as burning components, large to PCBA scrap. We can only try to avoid short-circuit generation, must grasp the production of each step, check without letting go of every suspicious point. So how to check and prevent PCB circuit board short circuit it?
1. If the manual welding, to develop good habits.
First, visually check the PCB board once before welding, and check with a multimeter whether the key circuit (especially the power supply and ground) is short-circuited.
Second, use a multimeter to test whether the power supply and ground are short-circuited after welding a chip each time.
In addition, do not fling the soldering iron when soldering, if the solder flung to the chip's solder pins (especially surface-mounted components), it is not easy to check.
2. Open the PCB diagram on the computer, light up the network of short circuits to see what is closest and most likely to be connected to a piece. Pay special attention to the IC internal short circuit.
3. Find a short circuit. Take a board to cut the line (especially suitable for single/double-layer board), cut the line after each part of the functional block will be powered on separately, part by part to eliminate. 4.
4. Use short circuit locator.
5. Be careful when soldering small size SMD capacitors, especially the power supply filter capacitor (103 or 104), the number is large, it is easy to cause a short circuit between power supply and ground. Of course, sometimes it is unlucky to encounter the capacitor itself is shorted, so the best way is to test the capacitor once before soldering.
6. If there is a BGA chip, because all the solder joints are covered by the chip can not be seen, and is a multilayer board (more than 4 layers), so it is best to split the power supply of each chip in the design, connected with magnetic beads or 0 ohm resistor, so that when there is a short circuit between the power supply and ground, disconnect the magnetic beads to detect, it is easy to locate a particular chip. Due to the difficulty of BGA welding, if not automatically welded by machine, a little carelessness will short-circuit the two adjacent power and ground solder balls.
Zhejiang NeoDen Technology Co., LTD., founded in 2010, is a professional manufacturer specialized in SMT pick and place machine, reflow oven, stencil printing machine, SMT production line and other SMT Products. We have our own R & D team and own factory, taking advantage of our own rich experienced R&D, well trained production, won great reputation from the world wide customers.
In this decade, we independently developed NeoDen4, NeoDen IN6, NeoDen K1830, NeoDen FP2636 and other SMT products, which sold well all over the world. So far, we have sold more than 10,000pcs machines and exported them to over 130 countries around the world, establishing a good reputation in the market. In our global Ecosystem, we collaborate with our best partner to deliver a more closing sales service, high professional and efficient technical support.