Welding technology of electric soldering iron
The soldering technique mentioned here refers to the fusion between metal conductors and solder commonly used in the production of electronic circuits. Solder is a lead-tin alloy with a melting point of about 183 degrees. Commercially available solder is often made into strips or filaments, and some solders also contain rosin, which is more convenient to use.
1. The method of holding the electric soldering iron (the welding technique of the electric soldering iron)
There are usually two ways to hold the soldering iron: the pen method and the fist method.
(1) How to hold a pen. Suitable for lightweight soldering irons such as 30W internal heating. Its soldering iron head is straight, and the head end is filed into a bevel or conical shape, which is suitable for soldering pads with a small area.
(2), fist method. It is suitable for high-power soldering irons. We generally do not use high-power soldering irons for electronic production (not introduced here).
2. Several methods of soldering leads on printed circuit boards.
There are two types of printed circuit boards: single-sided and double-sided. The through holes on it are generally non-metallized, but in order to make the components soldered on the circuit board more firmly and reliably, most of the through holes of the printed circuit boards of electronic products are now metallized. The method of soldering the leads on the ordinary single-sided board:
(1) Straight through the cutting head. The lead wire goes through the through hole directly. When soldering, make an appropriate amount of molten solder evenly surround the tin-stained lead wire above the pad to form a cone shape. After it cools and solidifies, cut off the excess lead wire. (see the blackboard for the specific method)
(2), buried directly. The lead through the hole is only exposed to an appropriate length, and the molten solder buries the lead tip inside the solder joint. This kind of solder joint is approximately hemispherical. Although it is beautiful, special attention should be paid to prevent false soldering.
Precautions for the use of soldering iron (soldering iron soldering technology precautions)
(1) The newly purchased soldering iron must be dipped in a layer of tin before use (energize the soldering iron, and then use the tin bar to approach the tip of the soldering iron when the soldering iron is heated to a certain point), and the soldering iron head that has been used for a long time File bright, then turn on the electric heating to heat up, dip the tip of the soldering iron with a little rosin, and tin it when the rosin smokes, so that the surface of the tip of the soldering iron is first coated with a layer of tin.
(2) After using the soldering iron for a period of time, there may be tin scale on the tip of the soldering iron. We can lightly wipe it off with a damp cloth when the soldering iron is heated. If there are pits or oxidized blocks, use a fine-grained file to repair or directly replace the soldering iron tip.
(3) After the electric soldering iron is energized, the temperature is as high as 250 degrees Celsius. When not in use, it should be placed on the soldering iron stand, but when it is not used for a long time, the power should be cut off to prevent the high temperature from "burning" the soldering iron tip (oxidized). It is necessary to prevent the electric soldering iron from scalding other components, especially the power cord. If the insulation layer is burned by the soldering iron without paying attention, it will easily lead to safety accidents.
(4) Do not hit the soldering iron violently, so as not to shock and break the heating wire or lead wire inside the soldering iron and cause malfunction.
