The correct operation method of welding technology in Yantai SMT processing

Welding is an indispensable link in the SMT patch processing process. If a mistake occurs in this link, it will directly affect the circuit board of the patch processing, making it unqualified or even scrapped. Therefore, when welding, it is necessary to master the correct welding method and understand relevant precautions to avoid problems.

Correct Operation Method for Welding Process:

1. Before welding in the patch processing, apply flux to the pad and treat it with a soldering iron to prevent poor tinning or oxidation of the pad, which could make welding difficult. The chip itself generally does not require treatment.

2. Carefully place the PQFP chip onto the PCB board with tweezers, being careful not to damage the pins. Align it with the pads and ensure the chip's orientation is correct. Adjust the soldering iron temperature to over 300 degrees Celsius, apply a small amount of solder to the iron tip, and use a tool to hold the aligned chip down. Add a small amount of flux to the pins at two diagonal positions, still holding the chip down, and solder the pins at these two diagonal positions to fix the chip so it cannot move. After soldering the diagonal pins, re-check if the chip's position is aligned. If necessary, adjust or remove and reposition it on the PCB board.

3. When starting to solder all pins, apply solder to the iron tip and coat all pins with flux to keep them moist. Touch the end of each chip pin with the iron tip until you see solder flow onto the pin. While soldering, keep the iron tip parallel to the pin being soldered to prevent bridging due to excess solder.

4. After soldering all pins, wet all pins with flux to clean the solder. Suck away excess solder where needed to eliminate any shorts or bridges. Finally, use tweezers to check for cold solder joints. After inspection, apply flux to the circuit board. Soldering SMT resistors and capacitors is relatively easier. You can first tin one pad, then place one end of the component, hold it with tweezers, solder one end, and then check if it is placed straight; if it is straight, solder the other end. Mastering welding skills truly requires a lot of practice.

The editor has finished explaining the correct operation method for the welding process, hoping it can help everyone. We must be strict with ourselves during operations to avoid creating many defects in our work. So everyone must pay attention. Although today's content is finished, you can follow Zhange Electronics so we can promptly push more content to everyone. See you next time.