Introduction to selecting electric soldering irons
Power selection of electric soldering iron
The power of the soldering iron used is too high, which can easily burn out the components (usually when the temperature of the junction of the transistor and transistor exceeds 200 ℃, it will burn out) and cause the printed wires to detach from the substrate; The power of the soldering iron used is too low, the soldering tin cannot be fully melted, the flux cannot evaporate, the solder joints are not smooth and firm, and it is prone to false soldering. Generally, it is used for welding integrated circuits, printed circuit boards, CMOS circuits, decorating transistors, IC type recorders, televisions, and conducting ordinary circuit experiments. It is generally recommended to use 20W. For repairing vacuum tube machines such as biliary machines and old instruments, it is recommended to use 35W, while for externally heated ones, it is recommended to use 45W. For welding the wiring of large transformers and grounding main lines on metal substrates, it is recommended to use internally heated 50W, externally heated 75W, and some higher power applications.
There are various shapes of soldering iron heads, and the key to choosing one is to regularly maintain a certain amount of solder, quickly and effectively melt the solder on the joint, without producing solder joints, overlap, or hanging, without burrs, and without damaging the board and components. If the solder joints on the machine are brand new and bright, the tin dipping section of the soldering iron head can be larger, and a flat or elliptical head can be used for fast heat transfer, natural operation, and convenience. The tin oxide layer is thick, and the soldering iron tip is relatively sharp, making it easy to break through.
Due to the high density of components, it is necessary to use corresponding sharp iron alloy heads to avoid burns and soldering. When assembling and disassembling IC blocks, special shaped soldering iron heads are often used. Sometimes, due to the inability to solder and the need to avoid damaging plastic parts, bent soldering iron heads are used. Of course, it also depends on each person's operating habits and hobbies.
How to choose an electric soldering iron
1. Selection of heating method based on electric soldering iron
(1) Selection of internal and external heating: When the power is the same, the temperature of the internal heating electric soldering iron is higher than that of the external heating electric soldering iron.
(2) When low-temperature welding is required, a voltage regulator should be used to control the temperature of the electric soldering iron. The temperature of the electric soldering iron is closely related to the power supply voltage. In practical use, the temperature of the electric soldering iron is often reduced by lowering the power supply voltage.
(3) Control the temperature by adjusting the extension length of the soldering iron head.
(4) There are several methods to stabilize the temperature of electric soldering irons: installing a regulated power supply to prevent changes in the power supply network; Maintain a certain volume, length, and shape of the soldering iron head; Using a constant temperature electric soldering iron; Maintain a constant indoor temperature; Avoid natural wind or electric fans, etc.
2. Selection of electric soldering iron power
(1) When welding low-power resistive and capacitive components, transistors, integrated circuits, printed circuit boards, pads or plastic wires, it is advisable to use 30-45W externally heated or 20W internally heated soldering irons. The best choice for application is to use a 20W internal heating electric soldering iron.
(2) When welding the welding points of general structural products, such as wire rings, wire claws, heat dissipation fins, grounding pads, etc., it is recommended to use 75-100W electric soldering iron.
(3) For large welding points, such as metal frame connectors, welding pads, etc., it is recommended to use 100-200W electric soldering iron.
