SMT FAQ In SMT chip processing, welding is a crucial link, which is directly related to the quality and reliability of electronic products. In recent years, with the improvement of environmental awareness, lead-free soldering has gradually attracted people's attention. So, what is the difference between lead-free soldering and leaded soldering in SMT chip processing?This article will analyze and compare from multiple aspects.
Lead soldering: In traditional lead soldering, the main components of solder are tin (sn) and lead (PB), where the lead content is usually between 30% and 60%. Lead is a toxic heavy metal that is harmful to both the human body and the environment.
Lead-free soldering: Lead-free soldering uses lead-free solder materials, the main components include tin (sn), silver (ag), copper (cu), etc. Lead-free solder has higher environmental protection and meets international environmental protection standards.
Leaded soldering: Leaded soldering has a relatively low melting point, typically between 183°C and 227°C. The lower melting point allows leaded soldering to have a wide process window and is easy to operate and control.
Lead-free soldering: Lead-free soldering has a higher melting point, typically between 217°C and 245°C. The high melting point makes the process window for lead-free soldering relatively narrow, and the requirements for equipment accuracy and process control are high.
Lead soldering: Lead solder has good wettability and fluidity, which can quickly fill the gap between the pad and the component pins, forming a reliable solder connection.
Lead-free soldering: Lead-free soldering has relatively poor wettability and flowability, requiring higher temperatures and longer times to achieve the desired soldering results. As a result, more refined operation and control are required during lead-free soldering.
Leaded soldering: Leaded solder has good mechanical properties and reliability, and can meet the requirements of most electronic products.
Lead-free soldering: Lead-free soldering has slightly lower mechanical properties and reliability than leaded soldering, but the performance and reliability of lead-free soldering can be further improved by optimizing the alloy composition and process parameters.
Lead soldering: Because the cost of lead solder materials is relatively low, and the process is mature and the operation is simple, lead soldering has certain advantages in cost.
Lead-free soldering: The cost of lead-free soldering materials is relatively high, and the equipment and process requirements are high, resulting in a relatively high cost of lead-free soldering. But with the improvement of environmental awareness and the advancement of technology, the cost of lead-free soldering will gradually decrease.
There are significant differences between lead-free soldering and leaded soldering in SMT chip processing in terms of composition and environmental protection, melting point and process window, wettability and fluidity, mechanical properties and reliability, and cost.
With the increasingly stringent environmental regulations and the continuous development of technology, lead-free soldering will occupy an increasingly important position in SMT chip processing. In order to meet market demand and improve product quality, SMT chip processing enterprises need to actively adopt lead-free soldering technology and continuously optimize process parameters and equipment configuration.