1. The tip of the soldering iron must be very sharp, but the soldering tip must be wiped clean before use. There is a sponge on the soldering station of the temperature-controlled soldering iron. Pour some water to make the sponge soak for the tip of the soldering iron.

2. The anti-static wrist strap can be replaced with high-quality wire according to the challenger. My method is: peel the copper core inside the two ends of the coaxial cable of about 2 meters, the length of the copper core is about 25 cm. Do not damage the shielded copper wire of the coaxial cable at the time of stripping. Flattening the shielded copper wire can replace the tin suction tape.

3. If rosin solder paste is not available, solid rosin can be dissolved in alcohol instead.

4. The solder wire does not need to be very thin, just 1.0mm. I used to think that the solder wire was 0.5mm and bought 0.5mm, but now I feel that this method is not necessary.

5. The minimum magnifying glass is 4 times, both head-mounted and desktop, I use a desktop magnifying glass (with fluorescent lamp inside).

■ Comparison of several welding methods

1. Spot welding: It is necessary to solder each pin with a relatively sharp soldering iron head, which has higher requirements on the electric soldering iron, and the soldering speed is slow.

2. Drag welding: faster than spot welding, personally feel that the welding effect is not as good as pull welding, sometimes the solder on the divided pins is uneven, and may be sticky.

3. Pull soldering: The things that are required are very general, especially the electric soldering iron. During the soldering process, the soldering iron head does not touch the pad but the solder ball. Because of the tension of the solder balls, the solder on each pin is very uniform and not much, very beautiful! Speed, skilled in the future will be faster than drag welding. This method can be described as a simple, reliable and inexpensive welding method.