The melting point of the solder is between 180 ~ 320C. Most metal materials can be welded by tin welding. During welding, the workpiece and welding section are heated at the same time, the solder melts and the welded workpiece does not melt.
The operation is convenient and the welding method is simple. Direct use of molten solder infiltration to achieve the solder joint, there are no precise requirements for heat and solder, the solder joint is easy to achieve.
For the same reason, this condition should also be used during disassembly. Generally, in the manufacturing plant, fewer components are removed by using a soldering iron. Like an IC, a hot air gun is used to heat the solder, and then the component is removed with a tweezers.
Morgann:
The melting point of the solder is between 180 ~ 320C. Most metal materials can be welded by tin welding. During welding, ...
Translation error (and a very common one too)! 
In English, the word is "soldering", not "welding" where you use either solder (tin/ lead +/- others), "silver solder" or "lead free solder" to join component leads. "Brazing" where a higher melting point brass filler rod is used.
"Welding" is used to describe the process where the actual metal being joined, is melted to make the join, with or without the addition of the same material as filler.
I just got into welding. I was not able to do it, and still not sure I can. Between the flashing, seeing my work - I am not sure my eyes are cut out for it. I got a better dimming module on the face-mask, that helps. I wound up catching my pants on fire, burned a hole though the back and down into my leg. I put that machine away for a while.
I am experienced with soldering, wires and metal. I fix the old metal tool boxes, solder hinges into place (after wasting a 1/2 a thing of big fat solder all over the floor). Made a Freddy-Kreugar knife glove for Halloween, from internet plans - that was fun.
They taught us at school that silver soldering was just another name for brazing. Admittedly this was before lead free soldering which can have a high silver content.
They did the brass braising when I worked in appliance repair - guy next to me soldered / repair air conditioners and humidifiers, the copper pipe. Looks easy. I was getting into trying to solder these aluminum parts with these aluminum sticks from the hardware store, and a small oxy & propane torch. I got a little bit into it before the rig started giving me problems and shut down my fun factor.
I ve done something like this before using my reflow oven.
Just used a fast reflow program and then turn the pcb upside down and hit it on a piece of wood.
Everything just drops off.