1.Production materials
High-temperature melting of tin has a strong permeability, but not all the soldered metal (PCB boards, components) can be penetrated, such as aluminium metal, the surface of which will generally automatically form a dense protective layer, and the different molecular structure of the internal molecules also makes it difficult for other molecules to penetrate into. Secondly, if there is an oxide layer on the surface of the soldered metal, it will also prevent the molecules from penetrating, we usually use flux to deal with it, or gauze to brush it clean.
2. Production flux
Flux is also an important factor affecting the pcba through the tin bad, flux mainly play a role in removing the surface oxides PCB and components and welding process to prevent re-oxidation of the role of flux selection is not good, uneven coating, the amount of too little will lead to poor through the tin. Can choose a well-known brand of flux, activation and wetting effect will be higher, can effectively remove the difficult to remove the oxide; check the flux nozzle, damaged nozzle need to be replaced in a timely manner, to ensure that the surface of the PCB board coated with the appropriate amount of flux, flux flux to play the effect of welding.
3. Wave soldering machine process
Pcba through the tin bad nature directly with the wave soldering process has a direct relationship, re-optimise the tin through the bad welding parameters, such as wave height, temperature, welding time or moving speed. First of all, the appropriate angle of the track down a little, and increase the height of the wave, improve the liquid tin and solder end contact; then, increase the temperature of the wave soldering, in general, the higher the temperature of the tin penetration of the stronger, but this is to consider the components of the tolerable temperature; Finally, you can reduce the speed of the conveyor belt, increase the preheating, soldering time, so that the flux can be sufficient to remove the oxides, soak the end of the solder to improve the amount of tin eating.
4. Manual welding
In the actual plug-in welding quality inspection, there is a considerable part of the weldment only after the surface of the solder to form a cone, and no tin through the hole, functional testing to confirm that many of this part of the virtual weld, this situation is mostly in the manual plug-in soldering, the reason is that the temperature of the iron is inappropriate and the soldering time is too short caused by the pcba through the tin is prone to lead to the problem of virtual soldering, increase the cost of repair. If the requirements of pcba through the tin is relatively high, the welding quality requirements are more stringent, you can use selective wave soldering, can effectively reduce the problem of pcba through the tin bad.
Features of NeoDen Wave Soldering Machine
1. Heating Method: Hot Wind
2. Cooling method: Axial fan
3. Transfer Direction: Left→Right
4. Temperature Control: PID+SSR
5. Machine Control: Mitsubishi PLC+ Touch Screen
6. Flux tank capacity: Max 5.2L
7. Spray Method: Step Motor+ST-6