Machine working concept: PCB will be moved in machine with stainless steel wheels conveyor system, after it’s stopped by stopper, it will be side clamped by rear clamper cylinder, then the spray fluxer will start to work under setting program, after that the same table will move x,y,z1,z2 to move different solder pot under PCB for selective soldering. During whole process, the top preheater can be on to help keep the PCB’s temperature.