Generally follow the following principles when choosing a soldering iron:
① The shape of the soldering iron tip must adapt to the surface requirements of the parts to be welded and the product assembly density.
② The temperature of the tip of the soldering iron tip should be compatible with the melting point of the solder, which is generally 30-80°C higher than the melting point of the solder (excluding the temperature drop when the soldering iron tip contacts the soldering point).
③ The heat capacity of the soldering iron must be appropriate. The temperature recovery time of the soldering iron tip must be adapted to the requirements of the surface of the welded part. Temperature recovery time refers to the time required for the tip temperature to return to the maximum temperature after it has dropped due to heat loss during the welding cycle. It is related to the power and heat capacity of the electric soldering iron and the shape and length of the soldering iron tip.
2. The power principles for selecting the soldering iron are as follows:
① When soldering integrated circuits, transistors and other components that are susceptible to heat, consider using a 20W internal heating or 25W external heating soldering iron.
② When welding thicker wires and coaxial cables, consider using a 50W internal heating or 45-75W external heating soldering iron.
③ When welding larger components, such as metal chassis grounding lug, you should choose a soldering iron with a power of more than 100W.
How to desolder
Desoldering is required during debugging and maintenance, or when components are replaced due to welding errors. Improper desoldering methods often cause damage to components, breakage of printed wires, or detachment of pads. Good desoldering technology can ensure the smooth progress of debugging and maintenance work and avoid increasing the product failure rate due to improper replacement of components.
Desoldering of common components:
1) Select a suitable medical hollow needle for desoldering
2) Desoldering with copper braided wire
3) Use an air bag solder extractor to desolder
4) Use a special desoldering iron to desolder
5) Use a soldering iron to desolder.
