ICT Christmas Seminar 2022: The Caliber of a ‘World Cup’ Event
Regardless of the potential distraction of the international football match between England and Wales in the World Cup competition, an enthusiastic crowd of PCB fans gathered in Meriden UK for the Institute of Circuit Technology Christmas Seminar, an eagerly-awaited networking opportunity that included a face-to-face industry welcome event and an outstanding technical programme.
New Insights into Selective Solder Nozzle Technology
The first presentation, delivered by Dr. Sam McMaster from the Functional Materials and Chemistry Research Group at Coventry University, was introduced by Technical Director Bill Wilkie, who began by remarking upon the success of Happy Holden’s recent series of engineering webinars. McMaster then shared his insights into wear mechanisms and future developments in selective soldering nozzles—a fascinating permutation of materials science, applied physics, and metal finishing in the practical context of a precision soldering technique that is currently growing in popularity.
Using video clips for illustration, McMaster described selective soldering as a process where individual through-hole components are soldered onto a PCB using a solder fountain programmed to move to each required position from underneath the assembly. The principal benefit of using a single-tube nozzle during this process is that each solder joint can be independently controlled with minimal thermal shock. This highly flexible non-contact process results in fewer solder defects.
Although current nozzle technology includes wetting and non-wetting versions for different applications, most of McMaster’s discussion concerned wetting nozzles. These have a limited-service life, and de-wetting issues during operation often cause increased maintenance downtime. The wear mechanism has been shown to be a complex mixture of corrosion and erosion effects. A KTP project is under way to develop a new base material with optimised composition, surface engineered for better wettability and increased lifetime, through corrosion resistance and initial wetting enhanced by electroplated and vapour-deposited coatings.
McMaster detailed the project methodology, from the evaluation of potential materials, coatings, and surface treatments, through to the production of initial prototype materials and new surface-engineered nozzles. New test methods have been established, mimicking real soldering conditions, to specifically study selective solder nozzles.
New insights have also been gained into the chemical reactions linking the wetting of solder to nozzles and the wear of nozzles. Alternative alloys and surface treatments have been developed to extend their lifetime and increasing their wettability; for commercial confidentiality reasons, however, McMaster refrained from disclosing further details during the presentation.
Flexible Circuits in Automotive Applications
Rapid growth in the utilisation of flexible circuits continues in automotive applications, especially in the electric vehicle (EV) sector. Representing a new corporate member of the Institute, Dr. Ioannis Kiratzis, chemical process engineer with Strip Tinning Flex, a division of Strip Tinning Automotive, introduced the company. Founded in 1957 and based in Birmingham UK, Strip Tinning has become a major supplier of components to a Tier 1 OEM base, specializing in antennas, smart glass, heating, lighting, and battery electronics.
Kiratzis discussed innovative solutions for EV battery modules, including flexible circuit applications for voltage and temperature control, and the manufacture of intelligent cell contacting systems for interconnection of individual cells within battery modules. He explained that, as a supplier to the automotive industry, the production part approval process is always a key consideration for the company. This industry standard outlines the process for demonstrating that engineering design and product specifications can be consistently met by the supplier's manufacturing process. Critical elements include accurate design records; a defined, monitored, and controlled process; and complete record-keeping and procedures for process failure mode effects analysis.
Strip Tinning Flex recently moved from screen printing to inkjet imaging. Their substrates include polyethylene naphthalate (PEN) and polyethylene terephthalate (PET) flexible polyester laminates, as well as polyimide; crimping is commonly used for solderless electrical connection in automotive assemblies. To meet growing demand, the company is currently focused on substantially expanding their flexible circuit manufacturing capacity.
Open Communication Produces High-quality Results
André Bodegom, managing director of Adeon Technologies in the Netherlands, now part of the CCI Eurolam Group, then delivered a powerful message in his presentation on industry cooperation: “Strong and open partnerships are a prerequisite for the real-time integration of design data and production results,” he said.
Bodegom began with some industry statistics and forecasts: The value of the global PCB market totaled $70.92 billion in 2020, of which the flex component doubled from 8% to 17% in recent years; the market is projected to reach a total of $86.17 billion in 2026 and as much as $130 billion by 2030. But although 93% of all production is currently coming from Asia, there is a clear trend toward increasing production in the U.S., followed by Europe. However, this shift will only happen if Europe makes a committed investment in greater automation in both hardware and software. Introducing and retaining intelligence throughout every stage of the manufacturing process is critical if Europe is to achieve better overall process control and alignment of different processes, with an aim toward higher traceability and self-learning algorithms.
Although increased growth is projected in European printed circuit board production after years of decline, the trend towards higher technology levels is the result of higher investment levels and growth in existing shops rather than an overall rise in the number of PCB factories in Europe. OEMs have inquired as to why they can’t get high-quality PCBs in the right volume in Europe anymore. The reality is that, over the last 30 years, OEMs abandoned their European suppliers by consistently buying from Asia. In the meantime, Europe has lost much of its capacity, and such capacity is not easily reinstated, especially at the technology and quality levels currently being demanded.
Bodegom has observed growing integration between design and the PCB, IC substrates, and EMS industries, with an increased demand for overlap between equipment, materials, and processes. He believes that the future lies in building strong teams and open partnerships with technical know-how to better support the entire electronics industry.
A fundamental element of future success is the sharing of data, and this, Bodegom said, must begin at the design stage. The vast majority of PCB design data is passed to the fabricator in Gerber format, which is an open ASCII vector format invented over 40 years ago that was intended to drive a photoplotter with basic machine commands. Using this format, all the intelligence built up during the design process is effectively lost at the output stage, forcing the PCB fabricator to try and recreate some of that intelligence at the CAM stage in order to create outputs for equipment like direct imagers, drill machines, AOI machines, electrical testers, etc., as well as chemical process lines. All this equipment not only uses data—it creates it. “What do we do with it?” Bodegom asked. “Practically nothing, other than occasionally using it retrospectively for tracing and identifying the cause of manufacturing defects.”
Adeon, together with some of its suppliers, has begun a project to gather that data, analyze it, and then feed it back into the loop—beginning with the design stage—to learn from the equipment how to control the manufacturing process. Bodegom re-emphasized that strong and open partnerships are a prerequisite for the real-time integration of design data and production results. Currently, much of the important data is not made available due to being blocked by machine suppliers for license reasons. Yet if that data could be read, it could be converted into a uniform communication link back into production. Artificial intelligence could then be used to analyze where improvements are needed. Bodegom gave several examples of equipment companies who are cooperating in the project.
Flexible Circuits Overcome Length Constraints
Back to flexible circuits—Philip Johnston, CEO of Trackwise Designs, introduced the intriguing concept of “Length-Agnostic FPC Manufacture.” The company, based in Tewkesbury UK, has developed a globally unique capability to produce multilayer flexible printed circuit boards of any length. In fact, they recently established a world record with an example circuit measuring 72 metres long. Johnston commented that the total length was governed only by the availability of suitable material.
Trackwise’s key markets are in the automotive, aerospace, medical and scientific & industrial sectors. In automotive applications, flexible PCBs are suited to EVs in battery modules, battery packs, and battery management systems. Examples include 6-ounce copper weights, which can carry high-voltage power. In aerospace, large-scale flex (LSF) offers a 70% to 90% weight reduction in data cables and a 10% to 20% weight reduction in power cables. They can be used for fuselage-length or full-wing-width interconnects and are qualified for high temperature operation in harsh environments. At the other end of the scale, long, ultra-flexible, and finely-etched printed circuits have become key enablers for catheter-based distal electronics, with tracks and gaps as small as 50 microns.
Although Trackwise has started to adapt rigid-board manufacturing equipment, their proprietary technique is based on roll-to-roll processing and digital imaging. The company successfully transitioned from technology based upon repeated and separated images to a machine-intensive manufacturing processes capable of non-repeated and non-separated images. To do this, significant challenges had to be overcome in software development. Plating was achieved by adapting continuous plating lines built for volume manufacture; pressing, on the other hand, was achieved by adapting a continuous press built for the manufacture of copper-clad laminate. Ultimately, equipment suppliers who were prepared to “buy in” to Trackwise’s vision made this transition possible. Trackwise’s process is patent-protected worldwide. Their standard practice is to panelize all circuits, regardless of size, into a 100-metre production roll.
Whereas roll-to-roll flexible circuits are primarily used in passive interconnect applications, Trackwise also has the capability to carry out roll-to-roll assembly, which opens up the potential for active interconnect, “smart harnesses,” and flexible hybrid electronics.
Trackwise is extending their manufacturing capacity via a new factory, which is nearing completion and is fully equipped for length-agnostic roll-to-roll flexible circuit manufacture and flexible circuit assembly.
A Greener Future Through Recyclable PCBs
Recyclable PCBs was the topic of the final presentation by Steve Driver on behalf of Jiva Materials. He gave an update on the evolution of Jiva’s Soluboard material and its current positioning in the world of PCBs. “I also want to encourage you to think a little differently about how this technology may fit in our world in future,” he said.
Driver acknowledged that the Institute of Circuit Technology has always been an effective platform for launching new ideas. His challenge was how to change the mind-set: “Everybody always wants to talk about what things can’t do. I’m an optimist and try to make everything positive. This might not become commercially viable within our lifetime, but it could be just the start of something good!” He call on the industry to engage with the Jiva philosophy and to cultivate a “It might just work” mindset.
Discussing recycling issues in the context of a throwaway society, and the pollution created by end-of-life electronics where the typical recycling process involve shredding and incineration, Driver made it clear that people are looking for alternatives. The leading edge of the laminate industry currently appears more concerned with high-speed and high-power performance than with recyclability. But at the other end of the spectrum, innovators are looking for something new to get excited about.
So why Soluboard? Driver referred to the 57 million tons of waste electronic and electrical equipment produced every year and used the mobile phone, which is commonly replaced every two years, as an example. Although a phone can be recycled, chargers are generally thrown away. A charger contains a simple single-sided PCB that can be made on a Soluboard substrate. According to Driver, 1.3 billion chargers equate to 4.3 tons of PCB waste.
Producers of electronic goods are legally required to deal with waste. A case in point is TV set-top boxes, the disposal of which is an expensive responsibility; recyclable PCBs can be an economically attractive alternative. Jiva has continued to receive inquiries from interested companies and has successfully provided many solutions. Although Soluboard currently represents only a tiny segment of the laminate industry, its market share is growing steadily as Jiva continues its mission to tackle electronic waste with naturally-derived printed circuit board materials by reducing carbon emissions and waste electronic and electrical equipment levels.
Martin Cotton Wins Honorary Fellowship
A very welcome seminar delegate was Martin Cotton, long-term supporter of the Institute and regular past presenter, who was determined to attend while continuing his slow recovery from serious illness. Everyone was delighted to see him and showed their sincere appreciation as he was awarded an Honorary Fellowship.
And the football score turned out to be 3-0 in England’s favour!