Analysis and elimination of reflow soldering failure

Reflow soldering has a relatively low failure rate during use, and the operation is relatively stable, but occasionally there are some minor problems. Simple reflow soldering failures can be analyzed and eliminated by yourself, as long as you understand these basic methods , We can quickly make a judgment and solve it. Let’s take a look at the common reflow soldering faults.

1. The temperature of the heating zone cannot rise to the set temperature, and the machine cannot reach the constant temperature state.

Cause investigation: ①. Broken heating wire or poor contact; ②. Inaccurate detection due to poor thermocouple connection or grounding; ③. Open solid state relay; ④. Excessive exhaust or indoor wind influence; ⑤. Improper temperature setting; ⑥The hot air speed is too low or the hot air motor is damaged;

Solution: ①. Disconnect the line and check the static resistance of the heating wire to see if there is disconnection or poor contact; ②. Check or replace the thermocouple; ③. Replace the solid state relay; ④. Adjust the exhaust plate to eliminate the influence of indoor wind; ⑤. . Reset the temperature; ⑥. Adjust the wind speed or replace the hot air motor:

2. The heating zone temperature exceeds the set temperature too much, and the over-temperature alarm will occur.

Cause investigation: ①. Improper temperature setting causes string temperature phenomenon; ②. Solid state relay breakdown; ③. Temperature controller out of control; 4. Inaccurate detection due to poor thermocouple connection or grounding; ⑤. Thermocouple and heating device Not corresponding; 6. The hot air speed is too low or the hot air motor is damaged;

Solution: ①. Reset the temperature; ②. Replace the solid state relay; ③. Check or replace the temperature controller; ④. Check or replace the thermocouple; ⑤. Check the wiring; ⑥. Adjust the wind speed or replace the hot air motor;

3. The temperature of the cooling zone is too high, and the over-temperature alarm is generated.

Cause investigation: ①. The chiller is faulty or the water temperature is set too high; ②. The cooling fan speed is too low; ③. The chilled water circulation is not smooth or the pipe is blocked; 5. The chiller is faulty and does not cool;

Solution: ①. Check the chiller and water temperature setting; ②. Reset the cooling fan speed; ③. Clean the heat exchanger; ④. Check the cold water circulation circuit and pipeline; ⑤. Check the chiller;

4. The rosin recovery fan has no action.

Cause investigation: ①. The AC contactor or thermal relay that controls the fan is damaged; ②. The external circuit is in poor contact; ③. The PLC output point or the intermediate relay is faulty;

Solution: ①. Replace the AC contactor or thermal relay that controls the fan; ②. Check the external circuit; ③. Check the PLC output point or change the intermediate relay failure;

5. The start-up light is off (START light), which means that the power input light is off.

Cause troubleshooting: ①. The START knob contact is damaged or the wiring is loose; ②. The main power air switch is not turned on or the auxiliary switch circuit is loose (CE); ③. UPS is faulty;

The lamp is faulty. Solution:①. Check the START switch And whether the wiring is in good contact; ②. Close the main switch and check the auxiliary switch and wiring; ③. Check the uPS and plug-in wiring; ④. Replace the bulb;

6. The conveyor belt does not move, the machine stops, and the interface displays an alarm screen for ultra-low speed.

Cause investigation: ①. Poor or damaged governor contact; ②. Poor or damaged analog output; ③. Transmission motor damage or poor contact at the power connection; ④. Transmission circuit protection fuse blown; ⑤. Drive chain Falling off or stuck; ⑥. Chain or mesh belt stuck;

Solution: ①. Check the wiring of the governor or replace it; ②. Check the wiring or replace the channel; ③. Replace the motor or check the power connection to check whether the speed sensor is working; ④. Replace the fuse; ⑤. Check the transmission part; ⑥.Check the conveyor chain mesh belt;

7. The transportation speed is unstable, the transportation is fast and sometimes slow, or the transmission chain network is jittery.

Cause investigation: ①. The transportation system is not lubricated enough; ②. The encoder is damaged; ③. The encoder coupling is damaged or loose; ④. The governor is faulty; ⑤. The pulse signal is interfered;

Solution: ①. Check the conveyor chain; mesh belt and master-slave drive system; ②. Replace the encoder; ③. Check or replace the damaged coupling; ④. Adjust or replace the governor; ⑤. Eliminate interference;

8. The hot air motor cannot be turned on, and the fan button has no response.

Cause investigation: ①. Improper setting of fan speed; ②. Incorrect setting of inverter parameters; ③. Damage to the relay to start the inverter or loose wiring; ④. The power supply is not connected (CE);

Solution: ①. Reset the wind speed; ②. Reset the inverter parameters; ③. Check the relay and circuit; ④. Check the power supply circuit;