For printed circuit board,what are the desoldering techniques for SMT processing?

What are the desoldering techniques for smt processing? It is generally not so easy to remove the smt processing components, in order to master?should practice often, otherwise, if forced removal, it is easy to destroy smd components. The mastery of these skills is of course subject to practice. Let me talk about it below:

The desoldering techniques for smt processing are as follows:

1. For components with small smd components, such as resistors, capacitors, diodes, and triodes, first tin the solder on one of the welding pads on the PCB, then use the tweezers to hold the components to the mounting position and hold the board against the left hand. Solder the soldered iron on the tinned welding pad to the right hand. The left hand tweezers can be loosened and the tin wire is used to weld the remaining feet. It is also very easy to disassemble such components, as long as the two ends of the component are heated simultaneously with a soldering iron, and the components can be removed after the solder is melted.

2. For smt processing components with more pins and wider pitch components, a similar method is used. First, tin is plated on one welding pad, then the left hand is soldered with a tweezers. , Then solder the rest of the feet with tin wire. The disassembly of such components is generally better with a hot air gun, a hand?held hot air?gun blows the solder, and the other hand removes the component with a clamp such as a tweezers.

3. For components with high pin density, the soldering step is similar, that is, welding?one foot firstly, then welding?the remaining legs with tin wire. The number of pins is relatively large and dense, and pin-to-pad alignment is critical. Usually the pads are selected on the corners, only a small amount of tin is plated, the components are aligned with the pads with tweezers or hands, the sides of the pins are aligned, the components are pressed on the PCB with a little force, and the solder is welded with a soldering iron. The corresponding pins of the disk are welded.

Finally, it is recommended that the high-pin-density components be disassembled mainly with a hot air gun, clamp the components with tweezers, blow all the pins back and forth with a hot air?gun, and lift the components when they are melted. If the removed component is still needed, then try not to face the center of the component when blowing, and the time should be as short as possible. After removing the components, clean the welding pads with a soldering iron.