The following points are derived from the
tin bar soldering mechanism and proved to be generally applicable by practical experience.
1. Master the heating time
Different heating speeds can be used for tin bar soldering, for example, if the shape of the soldering iron tip is bad, we have to extend the time to meet the temperature requirements of the tin bar when soldering large weldments with a small soldering iron. Prolonged heating times are detrimental to electronics assembly in most cases because
(1) The bonding layer of the solder joint exceeds the appropriate thickness due to long-term heating, causing the performance of the solder joint to deteriorate.
(2) Printed boards, plastics and other materials will be deformed and deteriorated if they are heated too much.
Conclusion: The shorter the time, the better, under the premise of ensuring that the solder wets the weldment.
2. keep the right temperature
If a high-temperature soldering iron is used to solder the solder joints in order to shorten the heating time, it will bring another problem: the flux in the solder wire does not have enough time to flow on the surface to be soldered and evaporates prematurely; the solder melts too fast Affect the function of the flux; because the temperature is too high, even if the heating time is short, it will cause overheating.
Conclusion: Keep the soldering iron tip at a reasonable temperature range. The general experience is that the temperature of the soldering iron tip is 50°C higher than the melting temperature of the solder.
Although this is contradictory, in actual operation we can obtain a satisfactory solution through the operation method.
3. Applying force to the solder joint with the tip of the soldering iron is harmful
The tip of the soldering iron transfers heat to the solder joint mainly by increasing the contact area, and it is futile to apply force to the solder joint with the soldering iron. For example, the welding points of potentiometers, switches, and connectors are often fixed on plastic components, and the result of added force is likely to cause the original components to fail.
