Reflow soldering is a key process in SMT chip processing. Various unexpected situations may be encountered during work. If the correct handling method and necessary measures are not taken, serious safety and quality accidents may be caused.
1. Matters needing attention
①The reflow soldering furnace must fully reach the set temperature (green light is on) before welding can be started.
②The temperature change of each temperature zone is frequently observed during the welding process, and the change range is ±1℃ (according to the reflow soldering furnace).
③When an abnormal situation occurs in the smt chip processing equipment, it should be shut down immediately.
④The size of the substrate cannot be larger than the width of the conveyor belt, otherwise it is prone to board card accidents.
⑤ Before welding, the smt processing plant should take protective measures (shield) or refrain from reflow welding for components that cannot withstand the normal welding temperature according to the regulations of the process documents or the component packaging instructions. Use manual welding or welding robots for post welding. .
⑥ During the SMT patch welding process, strictly prevent the conveyor belt from vibrating, otherwise it will cause component displacement and solder joint disturbance.
⑦ Regularly measure the exhaust air volume at the air outlet of the reflow welding furnace. The exhaust air volume directly affects the welding temperature.
SMT chip processing
2. Emergency handling
1. Card board
①If the board is stuck, don’t send the board into the furnace again.
②Open the furnace cover and take out the plate.
③Find out the cause and take measures.
④ When the temperature reaches the required temperature, continue welding.
2. Alarm
If an alarm occurs, stop welding, check the cause of the alarm, and deal with it in time
3. Sudden power outage
① When there is a power failure, do not send the plates into the furnace again. Due to the support of each power supply after the UPS, the conveyor belt or rail will continue to run. After the surface assembly board runs to the furnace mouth and all the surface assembly boards are connected out, open the furnace cover and cool down before stopping the machine.
②In unexpected situations, if the UPS is faulty, clamp the square shaft of the motor at the exit with a movable wrench to rotate it, and transfer the PCB from the furnace as soon as possible.