Training method for beginners to master manual soldering technology
Many electronic enthusiasts re-use a soldering operation method, that is, first dip some solder with the tip of the soldering iron, and then put the soldering iron on the solder joint to wait for heating and then solder to wet the weldment.
This method is not the correct method of operation. Although the weldment can also be welded in this way, the quality cannot be guaranteed. This is not difficult to understand from what we know about the soldering mechanism.
When we melt the solder onto the soldering iron tip, the flux in the solder wire will lie on the surface of the solder. Since the temperature of the soldering iron tip is generally above 250°C-350°C, the rosin flux will continue to volatilize before the soldering iron is put on the solder joint. , and when the soldering iron is placed on the solder joint, due to the low temperature of the weldment, it will take a while to heat up. During this period, most of the flux is likely to volatilize or even completely volatilize, so the wetting process is poor due to the lack of flux during the wetting process. 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 virtual welding. Moreover, after the protective effect of the flux is lost, the solder is easy to oxidize, and it is inevitable that the quality cannot be guaranteed.
1. 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).
2. 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.
3. 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.
4. remove solder
Remove the solder wire after a certain amount of solder has melted.
5. 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.
