A: The solder joint strength is not determined by whether they are “leaded” or “non-leaded” but by factors such as the solder composition, joint design, and application method. Leaded solder typically contains a small amount of lead, which helps to lower the melting temperature and increase the fluidity of the solder. This can make it easier to work with and create reliable electrical connections. However, leaded solder has been phased out in many regions due to environmental and health concerns.

On the other hand, a non-leaded solder is made from a combination of metals such as tin, silver, and copper. It has a higher melting temperature than leaded solder and requires more precise control during soldering. Non-leaded solder is considered more environmentally friendly and commonly used in electronics manufacturing industries.

Regarding mechanical strength, both types of solder can provide reliable joints when applied correctly. The strength of the solder joint typically depends on factors such as surface condition, cleanliness, quality of flux, and the level of heat applied during soldering. If all these factors are properly managed, both leaded and non-leaded solder can create mechanically strong connections.