Instructions for selecting a soldering iron
1. The selection of electric soldering iron generally follows the following principles:
① The shape of the soldering iron tip should adapt to the requirements of the workpiece surface and the assembly density of the product.
② The top temperature of the soldering iron tip should be adapted to the melting point of the solder, generally 30-80 ℃ 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 an electric soldering iron should be appropriate. The temperature recovery time of the soldering iron tip should be adapted to the requirements of the surface of the workpiece being soldered. The temperature recovery time refers to the time required for the temperature at the tip of the soldering iron to decrease due to heat dissipation during the welding cycle and then recover to the highest temperature. It is related to the power and heat capacity of the soldering iron, as well as the shape and length of the soldering iron tip.
2. The power principle for selecting an electric soldering iron is as follows:
① When soldering integrated circuits, transistors, and other heat sensitive components, 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 pads, a soldering iron with a power of over 100W should be selected.
We can choose electric soldering irons from the following aspects:
A: Based on the size of the solder joint, generally, the smaller the solder joint, the lower the power of the selected soldering iron, and the larger the solder joint, the higher the power of the soldering iron produced
B: Based on the size of the component being soldered, the larger the volume of the component, the thicker the pins, the larger the solder pads, and the larger the solder joints,
C: Based on the heat absorption capacity of the components, some components have a high metal content, so their thermal conductivity and heat dissipation characteristics are also good. In this case, a high-power soldering iron should be used for soldering
D: Choose from the welding area, the larger the welding area, the better its heat dissipation characteristics, so a high-power soldering iron should be used
E: Based on the density of solder joints, the higher the solder density, the lower the power of the soldering iron used In general, circuit boards should use soldering irons with a power of 30 W or less. For large capacity solder joints, a 40 W soldering iron can be used, but the soldering time should be controlled. Choosing an antioxidant soldering iron tip can make soldering smoother. For smaller solder joints, a sharper soldering iron tip should be used
