With the advent of environmental regulations that limit the use of lead-bearing solders in commercial electronics, many of the techniques used to form solder joints require adjustment and modification. This includes hand soldering as well as automated processes such as surface mount and mass flow soldering. The EMPF offers a course titled Lead Free Soldering in a Production Environment designed to ease the transition from historically well understood tin-lead processes to the new and often misunderstood lead-free processes.

The course is designed to be delivered at a customer’s location to assemblers, engineers, quality assurance, and management staff that are involved in the development and implementation of lead-free soldering processes. The course is one day in duration with a morning lecture session and an afternoon hands-on soldering session.

The material presented in the lecture session is designed to cover information directly pertinent for production staff. There are three primary topics presented: Material Issues, Manufacturing Processes, and Visual Inspection. The Material Issues session presents the various lead-free solder alloys, PCB finish materials, and component finish materials and the advantages and disadvantages of each. Also included as part of the Material Issues session is information about moisture sensitive components and mixing solder types on ball grid array assemblies.

The Manufacturing Processes session covers changes and adjustments that are required (or in some cases, the lack of changes required) for transition from tin-lead to lead-free processing. Presented are Screen Printing, Component Placement, Hand Soldering, Wave Soldering, Reflow Soldering, and Rework and Repair processes.

The Visual Inspection session is often the most anticipated session by the participants, as most inspectors know that the visual appearance of lead-free solder joints are different from typical tin-lead solder joints, even if they have never seen lead-free solder joints first-hand. This session covers the lead-free references contained in the IPC-A-610D and J-STD-001D, the special lead-free anomalies covered in the IPC-A-610D, a comparison of the visual differences between tin-lead and various lead-free solder joints, and finally the “rules of thumb” that are used for tin-lead solder inspection and how they change when applied to lead-free solder.

The goal of the hands-on soldering session is to introduce the students first-hand to the characteristics of lead-free solder joints and the minor technique differences that are required for lead-free hand soldering. Students are given the opportunity to solder with SAC305 (Sn96.5/Ag3.0/Cu0.5) and eutectic tin-copper (Sn99.3/Cu0.7) solders. Explained to the students is the proper way to determine the correct temperature setting for solder irons as well as how to modify a typical hand soldering technique to ensure solder joints that meet acceptability requirements. The students are self-paced under the guidance of an IPC Certified solder instructor and are given the opportunity to solder as little or as much as is necessary to gain a comfort level with the lead-free solders.

This course is best delivered at a customer’s location and with the customer’s own hand soldering tools, but the EMPF can supply the soldering equipment or deliver the class at its location adjacent to the Philadelphia International Airport. Companies interested in this course should contact the EMPF Registrar via email at registrar@empf.org or by phone at 610.362.1295 to obtain a quote and discuss scheduling.