What is the difference in effect between lead solder and lead-free solder?

There is a slight difference in the production process between lead solder and lead-free solder. Since lead-free solder contains no lead that can lower the soldering temperature, the soldering temperature will increase. The effect (or meaning) of the two is mainly reflected in personal safety and environmental protection. Lead solder is about to be completely banned, and lead-free solders will be widely applied.

Lead content in tin-lead solders varies from 10% to 95% depending on the application. Most of these are used as soldering solders for the electronics industry. However, lead is a persistent pollutant that cannot be decomposed by biological metabolism in the natural environment. Lead is harmful to most systems in the human body, especially the bone marrow hematopoietic system, nervous system and kidneys. High levels of lead in the blood can cause spasms, coma, or even death. Low levels of lead also have damage to the central nervous system, kidneys, and blood cells. Chronic lead poisoning can also cause high blood pressure and kidney damage. Therefore, many developed countries have banned the use of lead-containing coatings. According to the European Restriction of Hazardous Substances (RoHS) Directive 2002/95/EC, tin-lead solders have been banned. In the United States, strict limits have been imposed on the use of lead, allowing only one-hundred and fifty-fifths of the limit for connector manufacturers to be allowed to use, and each year they must publish their actual annual lead use. Japan also stipulates a material recycling law to increase the cost of recycling lead-containing products. China has also formulated the "Measures for the Control of Pollution Caused by Electronic Information Products." This will be promulgated in 2005 with an effective date of July 1, 2006, which is in sync with the EU's RoHS directive. Companies using leaded solders must be prepared to respond to the implementation of lead-free plans.