As incremental changes are made to transitioning into lead free manufacturing, the global demand for wave soldering continues unabated. Wave soldering offers cost effective ways to produce assemblies on a mass scale.  Equipment manufacturers are now presenting new revisions and modifications to equipment designs that are being driven by the need for Lead-Free conversion. New course offerings have been added, keeping with the demand for more comprehensive training in electronics manufacturing. A new wave soldering course has been introduced in the EMPF’s regularly scheduled course selections, with an expanded curriculum which includes both Lead-Free soldering, and Selective Soldering (Figure 4-1) as part of the Wave Soldering Course.

The curriculum offers a comprehensive view into the manufacturing processes associated with wave soldering from material selections to manufacturing methods. The material selection process will cover a variety of areas:

• Solder Alloys – Understanding the significance of the various microstructures, potential coarsening effects, and intermetallic formations.
  
  
• Board finishes – Exploring the rationale behind the selection of various surface finishes, the critical quantitative and qualitative aspects of  ENIG, Silver, Gold, and HASL finishes.
  
  
• Substrate impact. – Exploring of the effects of various mechanical and thermal properties of the various substrates with regard to the higher processing temperatures required.
  
  
• Components - Understanding the design and preparation for wave soldering, which can include adhesive attachments of SMT components for mixed technology assemblies

The manufacturing options for wave soldering have been modified over the past several years to include component selective methods of applying solder, as well as a “quick-change” solder pot capability to accommodate the various lead-free alloys. The manufacturing segment of the course is a hands-on opportunity for the student to familiarize themselves with the various process selections options:

• Thermal Profiling – Will teach the student how to properly prepare a wave soldering profile suitable for the specific application and assembly.
  
  
• Process Variables – Temperature, soak, environment, flux type, entry angle, and conveyor speeds are all important factors to be considered for meeting soldering requirements.
  
  
• Soldering Techniques – Includes the use of a laminar wave for PTH soldering applications, and a dancer wave for soldering on SMT components. The utilization of selective soldering system for applications where additional thermal stress on an SMT assembly is not suitable, will also be explored as an alternate method of wave soldering.
  
  
• Cleaning processes – Cannot be underestimated for their effect on the quality and reliability of the final product. An exploration of the various cleaning alternates, and process variables, along with their applications to meet certain class requirements, are an important consideration when choosing a cleaning system.
  
  
• Reliability issues - Potential reliability issues revolving around failures incurred due to improper soldering or subsequent cleaning will be explored. Issues like ion contamination, and solder joint corrosion commonly appear after a certain level of Environmental Stress Testing or Accelerated Stress Testing.
  
  
• Failure Analysis – Various optical and analytical methods will be discussed, such as X-Ray to ascertain potential solder joint failures that are most commonly diagnosed.

The opportunity to use the soldering and other equipment as part of the training experience is an important aspect of the EMPF’s Manufacturing classes. In addition to our scheduled classes, the EMPF can customize a wave soldering class specific to your needs at a time of your choosing. For more information on wave soldering or other classes offered by the EMPF, please contact the registrar by email at registrar@emfp.org or by phone at (610) 362-1295.