PCBA processing manual welding precautions

Matters needing attention during manual welding of printed circuit board assembly:

1. It must be operated with electrostatic ring. The human body can produce static electricity of more than 10000 volts, and the IC will be damaged when the voltage is over 300 volts. Therefore, the human body's static electricity needs to discharge through the ground wire.

2. Wearing gloves or finger sleeve operation, bare hands can not contact the machine board and the gold finger of the components.

3. Welding at the right welding temperature, welding Angle, welding sequence, and maintaining proper welding time.

4. Get the PCB correctly: hold the edge of PCB when taking PCB, and don't touch the components on the board.

5. Use low temperature welding as far as possible: high temperature welding will accelerate the oxidation of the soldering iron head and reduce the life of the soldering iron head.If the welding head temperature over 470 ℃.It's twice the oxidation rate is 380 ℃.

6. Do not pressure too much when welding: do not pressure too much when welding, otherwise it will cause the iron head to be damaged and deformed.As long as the soldering iron head is fully exposed to the solder, heat can be transferred.(depending on the size of the solder, choose different soldering iron heads, which can also make the iron head better heat transfer).

7. May knock or shake when soldering iron mouth: knock or shake soldering iron mouth can make the heater damaged and solder ball splashing, shorten the service life of heater, tin beads if splashed on PCBA may form a short circuit, cause poor performance.

8. Use wet sponge water to remove iron oxide and tin slag excess. Clean sponge to appropriate moisture content and moisture content not only failed to completely remove the soldering iron head more crumbs, also because of the welding head temperature fell sharply (this kind of thermal shock on the welding head and the inside of the soldering iron element, damage is very big) and produce the bad welding, such as welding, cold joint leakage water adhere to the PCB soldering iron head can cause circuit board as well as the corrosion and short circuit, if too little water to wet water treatment or not, will make the welding head is damaged, and cause no tin oxide, also easy to cause bad virtual welding such as welding.

Always check the water content in the sponge, and at least three times a day to clean the scum in the sponge.

9. When welding solder and flux should be appropriate. Soldering is overmuch, easy to cause the tin or cover up the welding defects, solder is too little, not only low mechanical strength, and because the surface oxide layer gradually deepen over time, easy to cause the solder joint failure.Too much flux can contaminate the PCBA, which may lead to electric leakage and other electrical problems.

10. Always maintain soldering iron head: this can reduce the oxidation chance of the soldering iron head and make the soldering iron head more durable.

11. The incidence of solder spatter and solder ball is related to the proficiency of soldering work and the temperature of soldering iron head;Welding flux splatter question: directly with the iron melt the solder wire, flux can rapidly warming and splash, when welding, adopts the method of solder wire is not direct contact with the iron, can reduce the flux of the splash.

12. When welding, be careful not to make the surface of the plastic insulation layer and components of the electric soldering iron around the wire, especially the products with a compact structure and complicated shape.