Soldering is a technique which is used during manufacturing or repairing of electrical and electrical equipment. A good solder joint should have low contact resistance and good mechanical strength to withstand vibrations. At times components become defective and need to be replaced. Extreme care should be taken while replacing the components so that the board does not get damaged due to heat. A few precautions are given below :-
- Clean the soldering surfaces of dirt, grease, oil etc. before soldering.
- Use temperature controlled soldering station with small tipped 25 watt soldering iron.
- While de-soldering apply heat to the lead and not to the board. Use de-soldering gun for removing the solder fillet.
- Before inserting new component see that the eye hole is clean and free from excess solder.
- Clean and bend the leads of the new component, insert it into the hole from the component side.
- Apply heat to the lead and solder with a regin care-solder. Apply solder wire to the lead and not to the soldering iron. Melting solder on iron and then applying to the lead is not recommended.
- Use heat for minimum time (not more than 5 seconds). Make certain that the soldering iron is fully heated. A less heated soldering iron will take more time and damage the board.
- Remove the excess flux from PCB with alcohol. Carefully examine the PCB for solder bridges between closely spaced leads and remove than before monitoring the PCB back in the equipment.
- Don’t try servicing PCB without a good practice use discarded PCBs for practice to acquire the necessary skill.
Suggested Practical :
- Demonstration of different types of soldering irons, de-soldering pump & wick.
- Soldering & de-soldering methods of different types of components such as registers, capacitors, coils, diodes and transistors.
- Soldering & de-soldering of ICs.
- Soldering & de-soldering of MOSFETs and dual RF transistors.
