General principles when choosing a soldering iron
1. The shape of the soldering iron head can adapt to the surface requirements of the weldment and the assembly density of the product.
2. The temperature of the tip of the soldering iron tip needs to be compatible with the melting point of the solder, which generally needs to be 30-80°C higher than the melting point of the solder (excluding the temperature dropped when the soldering iron tip touches the soldering point).
3. The heat capacity of the electric soldering iron must be appropriate, and the temperature recovery time of the soldering iron tip must be compatible with the requirements of the surface of the weldment.
The temperature recovery time refers to the time required for the temperature at the tip of the soldering iron tip to return to the highest temperature after the temperature of the tip of the soldering iron decreases due to heat loss during the soldering cycle. It is related to the power of the electric soldering iron, heat capacity, and the shape and length of the soldering iron tip.
Choose the power principle of electric soldering iron
1. When welding integrated circuits, transistors and other components that are vulnerable to heat, consider using a 20W internal heating or 25W external heating electric soldering iron.
2. When welding thicker wires and coaxial cables, consider using a 50W internal heating type or a 45-75W external heating type electric soldering iron.
3. When soldering larger components, such as metal chassis grounding pads, an electric soldering iron with a power of 100W or more should be selected.
Summarize:
The larger the tip of the soldering iron, the larger the heat capacity. When performing continuous soldering, the larger the tip of the soldering iron is, the less the temperature drop will be.
The heat capacity of the large soldering iron tip is high, and a lower temperature can be used during soldering, so the soldering iron tip is not easy to oxidize, and the service life of the soldering iron tip can be extended.
A soldering iron tip with a contact area between the soldering iron tip and the solder joint, a large contact area can produce effective heat transfer, and the size of the soldering iron tip is based on the standard that does not affect adjacent components. Soldering efficiency can be improved by choosing a geometry that allows sufficient contact with the solder joint.
The shape of the soldering iron tip is various. The selection points are: always keep a certain amount of solder, melt the solder on the joint quickly and effectively, do not produce false soldering, tinning, hanging tin, no burrs in the solder joints, and do not burn the board and components.
