Achieving Excellent Vertical Hole Fill On Thermally Challenging Boards Using Selective Soldering
Authors: Thomas Shoaf, Joseph Clure, and Denis Jean Company: Plexus Manufacturing Solutions Date Published: 10/16/2011
Abstract: The continuous drive in the Electronics industry to build new and innovative products has caused competitive design companies to develop assemblies with consolidated PCB designs, decreased physical sizes, and increased performance characteristics. As a result of these new designs, manufacturers of electronics are forced to contend with many challenges. One of the most significant challenges being the processing of thru-hole components on high thermal mass PCBs having the potential to exceed 20 layers in thicknesses and have copper mass contents of over 40oz. High thermal mass PCBs, coupled with the use of mixed technologies, decreased component spacing, and the change from Tin Lead Solder to Lead Free Alloys has lead many manufacturing facilities to purchase advanced soldering equipment to process challenging assemblies with a high degree of repeatability. Enter Selective Soldering; A technology combining the repeatability of a fully automated machine, with the flexibility of hand soldering, which can easily accommodate mixed technology components on highly complex PCB’s. While the introduction of the selective soldering process has provided the industry with a valuable tool for overcoming many challenges associated with PTH processing, equipment alone will not ensure the ability to solder a high thermal mass PCB. These difficult applications have proven that advancements in our techniques and process knowledge are just as critical as the advancements in equipment. With process development through experimental design in combination with the flux application, preheating combinations, and soldering techniques available on today’s Selective Soldering machines, excellent vertical hole fill on high thermal mass PCBs can be achieved.
Selective Soldering, High Copper Mass PCB’s, Thermally Challenging PCB’s