Is leaded or lead-free solder paste better?

The choice of solder paste, the comparison between leaded and lead-free solder paste, depends on a number of factors such as specific application scenarios, environmental requirements, cost considerations and soldering results. The following is a detailed analysis of the advantages and disadvantages of the two and the process and so on: 

Leaded solder paste

Advantages: Low cost: the cost of leaded solder paste is relatively low, which is mainly due to the price advantage of its raw materials. Good soldering effect: leaded solder paste has high glossy solder joints, stable soldering quality and low requirements for reflow soldering equipment. High electrical conductivity and mechanical strength: leaded tin solder has high electrical conductivity and mechanical strength, which can meet the needs of most electronic products.

Disadvantages: Environmental issues: Leaded solder paste contains lead elements, which is harmful to the environment and human health, and does not meet modern environmental requirements. With the global environmental awareness, more and more countries and regions prohibit the use of leaded electronic products. Health Hazards: Long-term exposure to elemental lead may lead to health problems and pose a threat to the health of operators.

Lead-free solder paste

Advantages:

Environmentally friendly: lead-free solder paste does not contain hazardous substances, which meets the requirements of environmental protection and is conducive to sustainable development.

Health and safety: the use of lead-free solder paste can reduce health hazards to operators.

Adapt to international trends: With the strengthening of global environmental regulations, lead-free solder paste has become the mainstream choice for the international electronics manufacturing industry.

Low-temperature soldering: Some lead-free solder pastes (such as medium-temperature and low-temperature solder pastes) can be applied to reflow soldering of devices that are not resistant to high temperatures, which expands the scope of its application.

Disadvantages:

Higher cost: Compared with leaded solder paste, the raw material cost of lead-free solder paste is higher, resulting in an overall increase in cost.

Difficult soldering process: Lead-free solder paste is relatively more difficult to process, requiring finer soldering techniques and stricter process control.

Mechanical strength of solder joints is relatively weak: compared with leaded solder paste, the mechanical strength of lead-free solder joints may be slightly weaker, but it can still meet the requirements in most application scenarios.

Conclusion

There are significant differences between lead-free solder paste and leaded solder paste in the soldering process. With the strengthening of environmental regulations and the acceleration of the trend of electronic products towards miniaturisation and high integration, lead-free soldering has become the mainstream choice in the electronics manufacturing industry. However, in practical applications, it is still necessary to choose the appropriate solder paste type and soldering process parameters according to specific needs to achieve the best soldering results.