The selection of suitable electric soldering iron will greatly improve the efficiency of electronic lead-free soldering. However, in general, the selection should be based on the actual situation of the object to be welded. Generally, the heating mode, power and shape of the soldering head should be considered.
1. According to The Choice of Heating Form of Electric Iron
(1) Selection of internal heating type and external heating type: under the same wattage, the temperature of internal heating type electric soldering iron is higher than that of external heating type electric soldering iron.
(2) When low temperature welding is needed, voltage regulator is used to control the temperature of electric soldering iron. The temperature of electric soldering iron is closely related to the power supply voltage. In practical use, the temperature of electric iron is often reduced by lowering the power supply voltage.
(3) The temperature is controlled by adjusting the extension length of the soldering head.
(4) There are several methods to stabilize the temperature of electric soldering iron as follows: add a regulated power supply to prevent the change of power supply network; keep the iron head in a certain volume, length and shape; adopt constant temperature electric iron; keep the indoor temperature constant; avoid natural wind or electric fan.
2. Power Selection of Electric Soldering Iron
(1) When welding small wattage resistance and capacitance components, transistors, integrated circuits, pads or plastic wires of printed circuit boards, 30 ~ 45W externally heated or 20W internally heated electric iron should be used. In application, 20W internal heated electric iron is the best.
(2) When welding the welding points of general structure products, such as wire ring, wire claw, heat sink, grounding pad, etc., 75 ~ 100W electric iron should be used.
(3) For large solder joints, such as welding metal frame connector, solder, etc., 100 ~ 200W electric iron should be used.