In the manual welding process of SMT patches, short circuit is a common poor processing. If you want to achieve the same effect of manual SMT patches and machine stickers, short circuit is a problem that must be solved. PCBA short circuit can not be used. There are many ways to solve the short circuit in SMT processing. The following SMT processing to give you a brief introduction.
How are SMT patches checked for short circuits?
1. Manual welding operation to develop good habits, with a multimeter to check whether the key circuit short circuit, each manual SMT patch an IC needs to use a multimeter to measure whether the power and ground short circuit.
2. Light up the short-circuit network on the PCB diagram, look for the most short-circuit place on the circuit board, and pay attention to the IC internal short-circuit.
3. In the SMT patch processing if there is a batch of the same short circuit, you can take a board to secant operation, and then each part of the short circuit is respectively energized to troubleshoot.
4. Use short-circuit positioning analyzer for inspection.
5. If there is a BGA chip, because all solder spots are covered by the chip can not be seen, and is a multi-layer board (4 layers above), so in the design of the power supply of each chip is divided, with magnetic beads or 0 resistance connection, so the power supply and ground short circuit, disconnected magnetic bead detection, easy to locate to a chip.
6. Small size SMT patch processing table stick capacitor welding must be careful, especially the power filter capacitor (103 or 104), the number is large, it is easy to cause power and ground short circuit.
