1. The components on the pcba board must not be missing parts, components are inserted reversely, and components are inserted incorrectly.
2. When plugging in components on the pcba board, one side cannot be high and the other low, or both sides are much higher at the same time.
3. If the PCB is horizontal, the components must be flat on the PCB, and the vertical components must be vertical and inserted on the PCB. There should be no swaying of the components and the defective phenomenon of the components not being inserted.
4. When inserting components such as transistors and ICs, pay attention to the direction and the pins of the IC should be aligned, and there should be no misalignment or offset. The components can be plugged in without flattening the pcba board, but it must be more than 1/2 plugged into the pcba board, not high from the pcba board.
5. When the pcba board is immersed in tin, the tin points should be fully and smoothly immersed, and there should be no undesirable phenomena such as submerged tin and dissatisfaction with the tin immersion of the tin immersion points.
6. When soldering the solder joints on the pcba board, do not use too much tin in the solder joints, otherwise there will be excessive solder joints and swelling. At the same time, the solder joints should be smooth and without shuttle corners, chamfers and gaps. Spot welding must be firm, and there should be no undesirable phenomena such as cracking tin.
7. The pcba board must not have such unfavorable phenomena as oxidation, desoldering, virtual soldering, loosening of pads, copper peeling, open circuit, short circuit and so on.
8. The finished pcba board must be cleaned with washing water or alcohol to clean the rosin and other impurities on the board to keep the pcba board clean and tidy.
9. The surface of the solder joints must have metallic luster, and the height of the solder joints should be more than 1/2 of the solder joint ends. The solder pads and the components of the solder joints form a 45-degree angle to climb the tin surface. The solder coverage rate is more than 80%, and the solder joints have no Fingerprints, no rosin, no cold welding and other bad phenomena.
10. When soldering, small solder joints are generally soldered with a soldering iron below 40W, and large solder joints are soldered with a soldering iron above 50W. When soldering, put the soldering iron on the soldering piece and heat it for a while, and then add a proper amount of tin wire, soldering iron and tin. The time interval of the silk is about 1-3 seconds.
11. When the pcba is processed and soldered, it must be heated evenly, and the soldering iron must heat the pins and pads at the same time, and at the same time feed the solder wire into the heating place.
12. When soldering, the side of the tip of the soldering iron and the side of the antenna of the component are rubbed with moderate light force to produce a frictional rough surface to fully dissolve the solder wire, so that the solder can be firmly connected to the component.
13. When welding oxidized welding materials, the oxide layer must be removed before welding to ensure the quality of the welded product.
14. After the soldering is completed, remove the solder wire first and then remove the soldering iron. The order cannot be reversed.
15. Wear an anti-static wristband when soldering ICs. One end of the electrostatic wristband should be well grounded to prevent damage to the IC.
16. During the soldering process, the soldering iron tip should be scrubbed frequently to avoid dirt or other impurities on the soldering iron tip from affecting the smoothness of the solder joints. Second, it is easy to cause the solder joints to sharpen, false solder and other undesirable phenomena.
17. When cutting the feet after welding, use diagonal pliers, and the cutting pliers should not be close to the circuit board, and should be about 2mm away from the circuit board to prevent the solder joints from being cut, and only cut off the excess ends.
