I believe that everyone knows about the lead-free wave soldering. Below I will collect the system and introduce a lead-free wave soldering for everyone. Including concepts - classification - advantages and uses.
The concept of lead-free wave soldering:
The wave soldering machine that has just been manufactured is not lead-free and lead-free! It is only differentiated when it is used. Generally, the lead-free wave soldering has a mark that is internationally common "pb" or lead-free mark. Leaded Wave soldering or lead-free wave soldering has no distinguishability on the outside. The main thing is whether the PCB produced contains lead. Lead-free wave soldering can directly produce leaded PCB. If lead is converted to lead-free again, the tin bath must be cleaned and replaced with lead-free tin.

Classification of lead-free wave soldering equipment:
Lead-free wave soldering equipment can be roughly divided into the following parts:
·Transmission system
· Flux coating system
·Preheating system
? Management module
·Welding module
·Control System
Since the wetting ability of the lead-free solder is lowered, in order to improve the wetting property, the device should have a nitrogen device because nitrogen can reduce the generation of dross and thus reduce the cost. Comparing the tin slag data and alloy cost of different alloys, the cost savings are still considerable.
Previous experience has shown that bismuth-containing solders should use the appropriate flux, so it is necessary to check the flux spray system; maintenance of the flux nozzle system and controllable flux throughput are important considerations.
The enthalpy will swell when cured, depending of course on the amount of cerium in the alloy. If it is not prevented, there is a danger of the tin furnace bursting, which requires ensuring that the solder will never solidify (cannot be de-energized) or use a tin furnace that compensates for this expansion.
If a lead-free solder with a higher tin content and a higher melting point is used, the impact is broader. We should consider in detail the effects of lead-free wave soldering switching on the components of the device:

Advantages of lead-free wave soldering:
Since the lead-free wave soldering has a unique superimposed vibration wave superposition, it can effectively drive out the gas in the SMT solder joint which is shielded from the brazing area due to the thermal decomposition of the flux and the adhesive agent, eliminating the jump welding and SMC, SMD In the shaded area, the SMT soldering requirements are met. At the same time, the superimposed wave of the lead-free wave soldering does not significantly enhance the hole-forming ability of the wave soldering, thereby improving the soldering reliability and the yield.
efficient. Since the three-phase asynchronous induction electromagnetic pump does not have a pulsating magnetic field component, the efficiency is greatly improved. According to the developed prototype, the peak width is 400 mm and the peak height is 40 mm. The magnetizing current of the three-phase induction pump is only about 5A. This working condition ensures that the three-phase asynchronous induction pump operates in a low heat and low current load state, ensuring long-term life reliability.
The lead-free wave soldering wave peak has no smoothing component. Because the three-phase asynchronous induction electromagnetic pump generates linear thrust instead of the blade rotary thrust of the mechanical pump, the peak is smooth, the liquid level disturbance of the tin bath is small, and the oxidation is slight.
The peak is stable. Because it is an induction pump technology, combined with the voltage regulation principle, when the grid voltage fluctuates by 10%, the voltage on the induction pump fluctuates by nearly 3%, so the peak is stable.

What kind of lead-free wave soldering method is adopted?
The use of lead-free wave soldering methods or processes depends on the complexity of the product and the yield. If complex products are to be produced and the yield is high, consider using a nitrogen process such as CoN▼2▼Tour peak to reduce dross and improve solder joints. Invasive. If you use a medium-sized machine, its skills can be divided into nitrogen and air processes. Users can still handle complex boards in an air environment, in which case corrosive fluxes can be used according to customer requirements, after soldering, or with low solids flux.