The correct way to use an electric soldering iron should be a five-step method:
ready for welding
Prepare solder wire and soldering iron. At this time, it is particularly emphasized that the tip of the soldering iron should be kept clean, that is, it can be stained with solder (commonly known as eating tin).
Heating the weldment
Touch the soldering iron to the soldering point, pay attention to keep the soldering iron heating all parts of the weldment, for example, the lead wire and pad on the printed board are heated, and then pay attention to let the flat part (larger part) of the soldering iron tip contact the larger heat capacity The weldment, the side or edge of the soldering iron tip is in contact with the weldment with a small heat capacity to keep the weldment evenly heated.
melted solder
When the weldment is heated to a temperature that melts the solder and the wire is placed on the solder joint, the solder begins to melt and wet the solder joint.
remove solder
Remove the solder wire after a certain amount of solder has melted.
remove the soldering iron
When the solder has completely wetted the solder joint, remove the soldering iron. Note that the direction of removing the soldering iron should be approximately 45°.
The above process takes about two or three seconds for general solder joints. For solder joints with small heat capacity, such as small pads on printed circuit boards, sometimes a three-step method is used to summarize the operation method, that is, the above steps 2 and 3 are combined into one step, and steps 4 and 5 are combined into one step. In fact, the subtle distinction is still five steps, so the five-step method is universal and is the basic method for mastering manual soldering iron welding. In particular, the time spent between each step is crucial to ensure the quality of welding, and it can only be mastered gradually through practice.
Welding Technology
1. How to hold the 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, an appropriate amount of molten solder is evenly surrounded by the tinned lead wire above the pad to form a cone shape. After it is cooled and solidified, the excess lead wire is cut off. (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.
3. Prevent poor welding
Soldering is a basic skill that radio amateurs must master, and it takes a lot of practice to master it.
