Advantages of soldering
Low power is required;
Low process temperature;
No thermal distortions and residual stresses in the joint parts;
Microstructure is not affected by heat;
Easily automated process;
Dissimilar materials may be joined;
High variety of materials may be joined;
Thin wall parts may be joined;
Keeping this in consideration, how bad is solder fumes?
All solder fumes can cause occupational asthma and other health problems (leaded and lead-free) if used for long periods at a time. The best solder wire contains something called Rosin that helps the solder flow when hot. This causes asthma if you are over exposed and is irreversible.