Update An Inside Look: UK Collaborative Research Project Dissemination Conference
The headquarters of the Surface Engineering Association in Birmingham, UK, was an appropriate venue for a one-day conference to disseminate the results of a number of UK and European collaborative research and development projects with direct relevance to the electronics manufacturing, surface engineering, and metal finishing industries.
The conference attracted an international audience from industry and academia, taking the opportunity to share and discuss the outcome of research on a range of new materials, manufacturing, and recycling approaches with a focus on both sustainability and the cyclic economy and offering the potential for more efficient production.
Dave Elliot, Surface Engineering Association
Dave Elliot, Surface Engineering Association chief executive, introduced and moderated the opening session. His first speaker was Dr. Andy Cobley from Coventry University who described how, as part of the multi-partner Susonence project, sonochemical processes had been applied to the tin-lead barrel plating of battery components, resulting in significant improvements in efficiency and productivity.
Dr. Andy Cobley, Coventry University
Low-frequency ultrasound had been demonstrated to improve electrolyte flow within the barrel, enabling the use of higher current densities without burning. Plating capacity had been increased and better uniformity of alloy composition had been observed. The applicability of sonochemistry to the electroplating of zinc-nickel alloy for the automotive industry was being investigated.
Karl Ryder, University of Leicester
Professor Karl Ryder from University of Leicester introduced a new TSB consortium project labelled Macfest--manufacturing advanced coatings for future electronic systems--which had spun out of the recently-completed Aspis project, where some interesting observations had been made when using types of ionic liquid known as deep eutectic solvents as an alternative to aqueous chemistry in the deposition of immersion gold on electroless nickel. Macfest set out to explore the fundamental molecular properties and interactions of nickel and gold in deep eutectic solvents with the objective of producing ENIG finishes with improved coating quality, solderability and wire-bondability by a process compatible with existing PCB manufacturing techniques and with the additional benefits of low environmental impact and no toxic components.
Dr. John Henderson, senior project Manager at C-Tech Innovation gave a progress report on the Stowurc multi-partner project, developing processes for the sustainable treatment of waste using recycled chitosans and intermediate derivatives prepared from crab shells to remove and capture metals such as copper and nickel from PCB manufacturing effluent. The project was nine months into a two-year programme. Techniques for the demineralisation, deproteination, and deacetylation had been investigated and costed, and extensive studies had been made of absorption rates and exchange capacities. Chitosan had been shown to be capable of achieving close to the benchmark performance of proprietary ion-exchange resin but production costs were not currently competitive. However, it appeared that demineralised shell could provide a cost-effective alternative for dealing with short-term incidences of high copper concentration in effluent.
Dr. Andrew Ballantyne, University of Leicester
The sustainable solder flux project, supported by IeMRC, was a further area of development in ionic liquid technology, presented by Dr. Andrew Ballantyne from University of Leicester. Deep eutectic solvents were finding many applications in metal finishing, plating, electropolishing, metal recovery and recycling. A particular attribute was their exceptional ability to dissolve metal oxides without the use of acids, and this offered the prospect of formulating environmentally-friendly soldering fluxes which would clean metal surfaces, prevent metal oxidation during soldering and hence maximise the wetting interaction between substrate and solder. Remarkable results had been observed in preliminary tests on copper, brass, stainless steel, and even cast iron--a material previously considered unsolderable using conventional fluxes.
Focusing specifically on PCB finishes, solderability tests had been conducted on a range including bare copper, OSP, ENIG, immersion silver, immersion tin, tin-lead HASL, and lead-free HASL, on test-pieces representing plated through holes, surface mount pads, and ball grid arrays, using a standard test flux as reference. In all cases, the DES flux showed excellent wetting, even enabling solder levelling directly on electroless nickel and introducing the prospect of a novel PCB finish, HASLEN. Collaboration with a solder paste manufacturer has demonstrated that DES-based pastes were feasible, and initial stencil-printing trials had shown promising results.
