Now that all lead-free soldering is used, factory-purchased electric soldering irons (soldering stations) cannot be purchased with traditional concepts. The ordinary temperature-controlled electric soldering irons on the market, although marked as being able to be set to 400 degrees or higher, in fact, their heat capacity and temperature recovery ability are not enough to handle lead-free high-temperature soldering in the case of colder solder joints. During soldering, lead-free tin wire with a melting point higher than about 34°C has a relatively large heat dissipation capacity. If an ordinary temperature-controlled soldering station is used to solder without increasing the temperature (especially when the solder joint is large) It will cause tin burrs, virtual soldering and too slow soldering speed due to insufficient heat energy replenishment; therefore, in order to achieve a suitable soldering effect, it is necessary to increase the soldering temperature of the soldering iron accordingly, but increasing the soldering setting temperature will bring many negative effects. ,
A. Lead-free tin wire is more easily oxidized than leaded wire, and high temperature plays a catalytic role, and the oxidation rate increases exponentially with the increase of temperature, so welding at extremely high temperature is very likely to cause mechanical contact virtual welding (The solder does not form an intermetallic molten alloy layer between the workpieces to be welded) and the solder joints are gray and white;
B. The ideal state of the soldering iron is not to leave the high temperature idle, to eliminate the energy storage, and to instantly add the energy obtained from the power source to the welding place, which can not only avoid the loss of energy to the greatest extent but also achieve good welding, but Ordinary soldering irons cannot be achieved due to the slow heating speed, and can only store enough heat energy to reach the temperature required by the soldering load by increasing the idle temperature, and the higher temperature will cause a great thermal shock to delicate components. , so that the circuit performance and the performance of the whole machine are directly or indirectly affected.
C. Generally electronic factories, especially optoelectronic product factories will have strict control on the setting of welding temperature. The lower the temperature setting, the better if it can meet the welding conditions. Therefore, a higher welding temperature cannot meet the welding process formulated by the factory. Require.
To buy a lead-free soldering station (soldering iron), you must first ensure two points:
1. Ensure that the soldering temperature is about 350°C
2. Ensure that the welding speed is 3-4 seconds for one solder joint
The ability to guarantee the above two points is called lead-free soldering station. If it is not advisable to increase the soldering temperature in order to meet the guaranteed soldering speed, it will affect the quality of solder joints and shorten the service life of the soldering iron tip.
Lead-free soldering stations (soldering irons) generally have several powers of 80W, 100W, 120W, and 150W. The lead-free soldering station (soldering iron) of 80W for most solder joints can be satisfied. If the solder joints are too large, a lead-free soldering station (soldering iron) with a higher power can be selected.
