Soldering is a kind of process through which the metal parts being connected by different kinds of alloy soldering tin. So the parts are capable of connected through surface molecule on the pretext of not being melted.
Soldering include SOFT and HARDEN, temperature of soft soldering below 450℃, temperature of harden soldering above 450℃. Harden Soldering usually be applied on silver, gold, steel and copper, it is soldering point is much more fastness than SOFT soldering, shearing strength is 20-30 times than SOFT soldering, these 2 heat-connecting mentioned above are all using SOLDERING, because the fundamental principle of both soldering methods are all inject the molten soldering tin into the long and narrow aperture of two clean surface of components.
Soldering ensure continuity of metal. First, if two metals connected with each other through bolt connection or physical adhesion, although it can be viewed as a compact integer, but this connection is discontinuous, sometimes if there is an oxidation-insulation film, then they aren’t even physical connection. Another drawback of mechanical connection compare with soldering is if the contact space keep on oxidation will increase the resistance value. Besides, vibration and other mechanical shock will loose the bolt. Soldering can eliminate these problems, soldering locations won’t have relative displacement, contact area won’t oxidize which can help to maintain continue conduction route. Soldering is a process during which 2 metal melted and combine with each other. When soldering tin in the state of molten, it can melt the metal where is being contacted by it, most of the time there could be a very thin oxidation film on the surface of soldering tin covered metal, flux hereby will play the role of melting this oxidation film. Soldering process normally includes:
1> Flux melt down which can help to strip off the oxidation film on the surface of metal;
2> Melt the soldering tin to make the impurity and lighter flux can float onto the surface;
3> Melt partly the metal which has connection with soldering tin;
4> Cold down and finish the fusion process.
PCB Repair need to orient root cause in the circuit board, so usually need to dissemble components from circuit board and do the necessary test and measurement, this process will include:
1> Dissemble special components;
2> Component test;
3> Replace those defected components;
4> Inspect circuit pattern functions;
Dissemble and replace other components will need to instruct soldering procedure.
