Not all materials can be connected by soldering. Only some metals have good solderability (strictly speaking, they should be solderable) can be connected by soldering.
Generally, copper and its alloys, gold, silver, zinc and nickel have good weldability, while aluminum, stainless steel and cast iron have poor weldabilityGenerally, special flux and method shall be used for tin welding.
The substandard composition of lead tin solder or excessive impurities will affect the solder quality, especially the content of some impurities, such as zinc, aluminum and cadmium.
Even the content of 0.001% will significantly affect the wettability and fluidity of solder and reduce the welding quality. It is obvious that no matter how clever a cook is,
he can't process delicious food with inferior raw materials.
Different fluxes shall be selected for welding different materials. Even for the same material, different fluxes are often used when different welding processes are adopted,
such as manual soldering iron welding and immersion welding. Different fluxes shall be used for cleaning and non cleaning after welding. For manual soldering, rosin and reactive
rosin can meet the assembly requirements of most electronic products. It should also be pointed out that the amount of flux must also be paid attention to. Too much or too little is not conducive to tin welding.
Reasonable solder joint geometry is very important to ensure the quality of tin welding. Due to the limited strength of lead and tin, it is difficult to ensure the sufficient strength of solder joint,
and the joint design has been greatly improved. The influence of different lead and hole sizes on the welding quality of through-hole mounting components on printed board.