The five-step training method for soldering iron
As a training method for beginners to master manual soldering technology, the five-step method is very effective and deserves to be discussed as a separate section.
Many electronics enthusiasts follow a soldering method, which is to first dip some solder into the tip of the soldering iron, then place the soldering iron on the solder joint and wait for the solder to wet the solder piece after heating.
This method is not the correct method of operation. Although the welding parts can be welded in this way, the quality cannot be guaranteed. It is not difficult to understand this from what we know about the soldering mechanism.
When we melt the solder onto the soldering iron tip, the flux in the solder wire lies on the surface of the solder. Since the temperature of the soldering iron tip is generally above 250℃-350℃, the rosin flux will continue to evaporate before the soldering iron is placed on the solder joint. , and when the soldering iron is placed on the solder joint, due to the low temperature of the solder joint, it will take some time to heat up. During this period, the flux is likely to evaporate mostly or even completely. Therefore, during the wetting process, the wetting is poor due to the lack of flux. At the same time, due to the large temperature difference between the solder and the weldment, the bonding layer is not easy to form, and it is difficult to avoid false soldering. Moreover, due to the protective effect of the flux, the solder is easily oxidized after death, and it is inevitable that the quality cannot be guaranteed.
The correct method should be a five-step method:
1. Preparing for welding
Get soldering wire and soldering iron ready. At this time, it is particularly emphasized that the head of the soldering iron must be kept clean, that is, it can be stained with solder (commonly known as eating tin).
2. Heating weldments
Touch the soldering iron to the soldering point. Firstly, keep the soldering iron heating all parts of the soldering piece, such as the leads and pads on the printed circuit board. Secondly, pay attention to allowing the flat part (larger part) of the soldering iron tip to contact the parts with larger heat capacity. The side or edge part of the soldering iron tip contacts the weldment with smaller heat capacity to keep the weldment evenly heated.
3． Melted solder
When the weldment is heated to a temperature that can melt the solder, the soldering wire is placed on the solder joint, and the solder begins to melt and wet the solder joint.
4． Remove the solder
When a certain amount of solder has melted, remove the solder wire.
5. Remove the soldering iron
When the solder completely wets 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 a general solder joint. 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 soldering. In particular, the time spent between each step is crucial to ensuring welding quality, and can only be mastered gradually through practice.
