EIPC Summer Conference, Berlin: Day 1
Berlin, capital of Germany and a world city of culture, politics, media and science, was the venue for the 2015 EIPC Summer Conference, which attracted delegates from sixteen countries, including Russia, Hong Kong, Japan, Israel, USA and Canada, as well as the European Union, to experience a programme of 21 technical presentations over two days. Also included was a visit to the Berlin laboratories of Fraunhofer Institute, Europe’s largest application-oriented research organisation.
EIPC Chairman Alun Morgan extended a warm welcome to delegates, but was sad to report the passing of Brian Haken, whose name had been synonymous with the foundation and direction of UK and European printed circuit trade associations for many years.
Morgan followed his opening remarks with a keynote market overview and business outlook for the global electronics industry, presented on behalf of industry analyst and EIPC board member Walt Custer.
Custer, noted for the alacrity of delivery of his statistics and trend lines, has a worthy deputy in Morgan. A mesmerising blur of information of the highest calibre, delivered at Custer-pace-plus!
Market Overview Highlights
Global and Eurozone purchasing managers’ indices remained marginally on the side of growth, and world electronic equipment revenues were showing year-on-year revenue growth of about 1.7%, with a similar trend in Europe. Of a world PCB sales total of $60 billion, Europe represented about 4% and North America 5%.
With acknowledgement to Michael Gasch for source material, Morgan reported that the European PCB industry had an acceptable year in 2014 though with only about 0.7% growth, and this was counter-balanced by losses due to the closure of some manufacturers, and stagnation in overall volume was seen as a consequence of ongoing transfer of high-volume business to Asia. A group of five countries (Austria, Switzerland, Germany, France and UK) accounted for almost 80% of total European production volume. The automotive industry was sourcing only innovative products in Europe, more than 90% of its needs coming from outside Europe, and the increasing share of electronics per vehicle did not result in higher revenues for the PCB industry. In fact, there had been a net decline since 2010. The European production value of the highly competitive consumer, communication, and computer industry market sectors had dropped by more than a third since 2010 and supplies of PCBs for industrial electronics had declined year-on-year by1.4%. The UK and France remained very active in supplying the defence, aeronautic and space industries, which had achieved strong growth in sales. The total number of manufacturers declined again in 2014, and in most cases the companies going out of business had been small, whilst others had joined larger groups to secure their survival. The manufacture of standard technology PCBs was falling at a slower rate than expected, and HDI, flex and flex-rigid had shown substantial growth.
Custer’s World PCB model forecast 2.5% growth for the current year, and leading indicators suggested 1% growth in Europe.
Having concluded the market overview, Morgan called forward EIPC board member Oldrich Simek of Pragoboard (Czech Republic) and presented him with a plaque acknowledging his enormous contribution over many years and bestowing upon him Honorary Fellowship of the Institute.
‘New Technology’ was the theme for the first technical session, which began with a presentation from Sven Lamprecht, director for technology and market assessment in the Electronics Division of Atotech Deutschland, entitled “Smart manufacturing systems pave the way for embedded technologies.” He considered the implications of the “More Moore” and “More than Moore” extensions of Moore’s Law in terms of the challenges they presented in the manufacture of package substrates. Over the coming five years, microvia diameters were forecast to trend to 20 microns, solder resist openings to 30 microns, and lines and spaces to three microns. Two major issues were the warpage and modulus of organic-based substrate materials, and glass was seen as a potential solution. Two major research groups were working on glass-based developments, Georgia-Tech Package Research Centre and Fraunhofer-Corning, and the first glass-core demonstrators had been produced, although there were still concerns about the effects of thickness and height variation on yield. “PowerPoint Engineering” did not accurately reflect the realities of surface topography on manufacturing yields. An alternative manufacturing proposition was to embed conductor features into the substrate, by direct laser structuring and panel plating without photoresist. The Laser-Embedded-Conductor Substrate had already been demonstrated. Lamprecht considered that many solutions to tomorrow’s challenges could be entirely new and disruptive, rather than modifications to existing methods.
Mike Morianz, manager of technology and innovation in advanced packaging at AT&S in Austria, announced that embedded power electronics was on the way to be launched in serial production. Embedded components had a long history in AT&S, and the HERMES project, which ran from 2008–2011 had involved the whole supply chain in developing a technology for embedding active and passive components in PCBs, allowing more functional integration and higher density. The technology was based on established PCB manufacturing and assembly procedures and standard available silicon dies.
A major project currently in progress was EmPower, which aimed at developing an innovative packaging concept for the drive electronics of engines in electric vehicles, where the power components—IGBTs, MOSFETs and diodes—were embedded as thinned chips into glass-reinforced epoxy-resin multilayer builds to enable large-area interconnections and form conductor structures with the lowest possible electrical impedance and optimum heat removal by embedding the power semiconductors in a module offering heat removal by the shortest possible heat conduction paths. The EmPower consortium had benchmarked reference designs against existing packaging solutions and were carrying out thermo-mechanical simulation and reliability testing, and a 500-Watt test vehicle was proposed as the second demonstrator on their power roadmap where a longer-term target was a 50kW DC to AC converter.
The EmPower project set out to develop processes to enable a large manufacturing organisation to produce boards with embedded devices in high-volume production. But what scope was there for the smaller PCB fabricator to become engaged in embedded technology? François Lechleiter from Cimulec Group in France gave a presentation on the development and validation of PCBs with embedded passive components for low-volume, high-end applications. He outlined the Euripides "Board-On-Board Technology" project, which aimed at achieving increased density by embedding 0402 de-coupling resistors and capacitors in high Tg glass-epoxy substrates using the capabilities of a small PCB fabrication shop. Reliability was required to be to the long-term, harsh-environment standards demanded by civil avionics and telecommunications applications, and repairability was a further requirement. There were nine partners in the project, with a strong interaction between PCB fabricators, OEMs and EMS companies. The focus of this work package was the development of the PCB core containing the embedded passives. First step was to place the components on a carrier substrate, then create the core with this carrier and components, and build a rigid multilayer structure on it, resulting in a 10-layer multilayer with embedded 0402 components sandwiched between layers 5 and 6. Co-development between manufacturer and OEM had enabled robust design-for-manufacture rules to be established. Standard off-the-shelf passive chips with copper terminations were used, and interconnections between chips and copper tracks were made by laser drilling and copper plating. This basic structure gave the opportunity to optimise most of the critical procedures involved in the embedding operation, particularly in the complete filling around the components with resin, without voids or cracks. Initial reliability assessments on test vehicles had given good results, and long term tests were ongoing. The project was currently at the stage of final demonstrator manufacture, most of technical development work had been completed and here was an optimistic expectation that the embedding technology would fulfil the OEM requirements.
Whenever new technologies are developed, standardisation is needed to support development and industrial progress. Walter Huck, general manager of quality and environment at Murata Electronics Europe gave an update with reference to IEC and made a convincing argument for involving standards organisations at the earliest stage of the project. He commented that international standards bodies, national bodies, consortia and private bodies coexisted but rarely cooperated, and that standardisation organisations were not really integrated. When innovation involved the development of complex new system technologies, embedding technology being a prime example, long-term cooperation of the various industries, standardisation bodies and interest groups was required, along the whole value chain and aligned with technology roadmaps. And a strategic approach was necessary if the innovation was to become a market success, with standardisation as one of the priorities.
Huck described the approach taken by the IEC TC 91 Assembly Technology committee, and the standardisation strategy adopted by JISSO, from technology roadmap, through standardisation roadmap and publication plan, to the work programmes of the cooperating committees, resulting in the IEC 62878 Device Embedded Substrate series, four parts of which were already published, two were at draft stage, and a new generic specification was in preparation.
But what of embedding for high-power applications? No safety standards were yet in existence, and it could take several years to generate them. “If you want the technology available to the mass market in 2020, you’ve got to start developing standards and test methods now!”
Theme for the second technical session was the status of inkjet in PCB fabrication, with presentations from three industry experts and this author as moderator.
Being cost-effective with imaging technology was the subject of the presentation by Gregory Stoeckli, managing director of First EIE in Switzerland. “What do European PCB shops look for when investing in manufacturing equipment?” he asked, and with amusing but meaningful illustrations, he demonstrated how perception, awareness and intuitive understanding varied depending on people’s positions and points of view, those of the managing director and the production manager being typically contrasting examples. He clarified the difference between efficient and effective, stressed the importance of flexibility, and observed that the most effective solution need not be the most expensive. In the case of PCB fabrication, the typical SME was looking to produce complex PCBs as quickly and cost-effectively as possible, and was always eager to increase his margin without raising his price, by working more effectively and flexibly and maximising his yield. First EIE’s background was in film imaging and they had been in the business of developing and supplying photoplotters for over three decades. They had produced their first inkjet legend printer in 2002 and were now in their third generation of drop-on-demand equipment. Their emphasis was on flexibility, simplicity in operation and low-cost maintenance, and at 80% duty cycle their equipment could print 60 panels per hour at 600 dpi resolution with on-the-fly UV curing and a power consumption of only 400 watts. “Don’t believe all you read on data sheets!” was Stoeckli’s advice when making equipment choices.
Dr. Boaz Nitzan, VP of functional inkjet technology at Camtek, in Israel, gave a detailed description of the recently introduced Gryphon SL, described as a full digital manufacturing station for PCB solder mask and legend by ink-jet technology. The equipment represented the latest innovation in Camtek’s 3D functional inkjet system and offered a “one-stop-shop” for solder mask and legend deposition by 3D inkjet technology, replacing both the traditional solder mask and the legend application and imaging processes in PCB manufacturing. It was designed to enhance production by improving accuracy, reliability and yield, whilst reducing manpower demand and eliminating the need to treat waste products from the process.
The system used real-time alignment and built-in AOI to match the image to the actual panel, and the print-head recognised and followed the 3D topography of the PCB surface. The ink was immediately tack-dried with a built-in UV curing system. From a process point of view, the system had the advantages of reducing the number of stages from seven to three and the capability to print solder mask and legend consecutively from a single alignment, with consequent reduction in process cycle time. It occupied very little floor space and required only a single operator. Technical benefits included the ability to achieve zero clearance, to print different thicknesses in different areas, and to print gloss, semi-matte or matte from the same ink. Total cost savings of almost 50% per panel could be achieved compared with photoimaging processes.
Don Monn, European sales and new product development manager for Taiyo America, took the published theme of the conference: “Improve profitability through technical leadership and innovation to meet future market requirements,” as the basis for a thought-provoking debate on the question: “Inkjet soldermask: Is it right for you?” delivered in his distinctive animated style, with the underlying message of getting things right first time. He went to great lengths to determine the real costs of rework and scrap—going far beyond those immediately visible, then analysed to the same level of detail the actual costs of the photoimageable solder mask process in a typical high-mix PCB fabrication shop manufacturing 3,500 panels per month, 50% screen-coated, 50% spray-coated. Not just the prime costs of materials and tooling, operator costs and equipment running costs but all of the peripheral consumables, down to squeegee rubber and sticky tape—amazing how all of these seemingly trivial costs added up to a substantial total! Returning to the keyword in the conference theme, he remarked: “Profitability is not a dirty word where I come from!” and reiterated the “Do it once, do it right” message as a preface to the fast-approaching point in time when technology, in the shape of production-proven ink-jet equipment and end-user qualified inks, would help the industry increase its profit margins.
This session provoked more interactive dialogue than any other in the conference programme. Dr. Nitzan in particular was inundated with requests for additional information and explanation on equipment capability and material performance, and delegates would have missed a substantial proportion of their lunchtime break if I had not reluctantly brought the discussion to a close.
Theme of the afternoon session was the evaluation of new materials, processes, packaging and PCBs for the next generation of electronics “Made in Europe,” and was focused on the work of the Fraunhofer Institute for Reliability and Microintegration IZM in Berlin, with three technical presentations, moderated by Fraunhofer’s Dr. Michael Töpper, followed by a visit to the Fraunhofer IZM laboratories in Berlin Mitte.
Dr. Ivan Ndip, head of the department of RF & Smart Sensor Systems, examined the demands on the PCB for future RF applications, with particular reference to the role of RF systems in the Internet of Things. IoT had a layered architecture: a device layer with RFID and RF sensor systems, a network layer of high-speed optical communication systems, a service and applications support layer with cloud computing systems for Big Data, and an applications layer, with RF wireless communication systems. System-integration technologies were the fundamental building blocks of RF systems, and for future RF applications the PCB could be considered either a key enabler or a bottleneck, it needed to ensure signal and power integrity whilst minimising electromagnetic interference. Critical material parameters were surface roughness and surface finish of the metallisation, and homogeneous permittivity, low moisture absorption, wide frequency range stable over a wide temperature range and low-loss tangent of the dielectric. Fraunhofer had developed a holistic and systematic approach to testing and evaluating PCB materials, in cooperation with manufacturers like Isola and Corning, and were now able to predict the issues at PCB level that could compromise RF performance, through 3D full-wave simulation, layout, fabrication, test structure design and RF measurement. Dr. Ndip discussed the RF design of interconnects in multilayer PCBs, gave examples of RPD problems and how new design measures could optimise the electromagnetic performance of vias without using decoupling capacitors. He then considered the design, simulation and measurement of integrated antennas, showed the correlation between simulated and measured values, and demonstrated how a 77 GHz antenna could be completely de-tuned as a consequence of typical PCB manufacturing tolerances.
Lars Böttcher, project manager, embedded die technologies at Fraunhofer IZM gave a fascinating insight into next-generation PCB and panel-based packages using embedding technologies. He explained that cost reduction in semiconductor packaging could be achieved by an increase in production format size, and PCB embedding technology offered a potential solution, although for next-generation panel-level packaging, advanced processes and materials would be needed, together with improvements in resolution and accuracy. Warpage remained a major challenge, and polymer materials with controlled CTE and modulus, together with low shrinkage, were required, with designs optimised in terms of layer sequence and build-up. However, the production of embedded packages was ramping up rapidly. Already established in power and logic applications, growth would be seen in the smartphone and computer markets, and embedding technology would soon be implemented at PCB manufacturers, semiconductor manufacturers and outsourced assembly and test (OSAT) companies. Fraunhofer IZM had already established a complete PCB manufacture and assembly line for substrate integration on 24” x 18” panels, and Böttcher described process sequences for embedding bare chips, packaged components and passive components using solder or adhesive interconnects or alternatively direct copper interconnects, with examples of applications in modular systems.
Böttcher discussed Fraunhofer’s collaboration in the EmPower Project which had been referenced in the earlier presentation of Mike Morianz from AT&S. The project aimed to industrialise double-sided copper plating on wafer level as a route to industrialising next-generation automotive power modules, and to combine high-performance with small form factor. The process concept was based on epoxy coated foil or prepreg and copper foil with direct microvia connection from top and bottom side, which required double-sided copper metallization of the semiconductor. No soldering or sintering was used for die-attach, which was achieved by hot-bonding to B-stage epoxy resin. Power cores fabricated using the process were bonded to an IMS substrate with thermally conductive prepreg, and high-current connections were made by silver sintering. A 500-Watt demonstrator had been produced and it was forecast that power devices based on this technology would soon be in volume production.
‘Reliability and Environmental Aspects for Future PCB’ was the topic of Dr. Olaf Wittler, head of environmental and reliability engineering at Fraunhofer IZM. He made it clear that environmental concerns would continue to be important technology drivers in the electronics industry. In the recent past, regulations such as the RoHS and ELV directives had resulted in increased performance demands on PCBs, and certain RoHS exemptions, originally permitted because of a lack of appropriate substitute materials, were due to expire in the near future. New trends in use conditions, particularly in power and LED applications, continued to increase the temperature load on the PCB. Fraunhofer IZM had developed material characterisation techniques to determine copper properties and monitor dielectric degradation and were now able to measure yield stress of copper within via holes and non-destructively compare, test and qualify polymer dielectric materials for long term and high-temperature use. The reliability of solder joints at high temperatures was also an issue. New interconnect technologies were under development, capable of operating at high temperatures and showing higher reliability than standard interconnection methods. Environmental considerations such as the need to avoid climate change and save energy were driving the development of LED lighting and power electronics. There was a continuing trend towards improved resource efficiency and a consequent need for highly reliable electronics, and ongoing research at Fraunhofer IZM would determine how this trend would influence future electronics manufacturing.
At the conclusion of the technical session, delegates had the opportunity of a refreshing 2 km walk to Fraunhofer IZM (because the bus didn’t arrive!) and a privileged tour around the photonics laboratory, the power laboratory, and the former flip-chip line, now converted to an embedding line. And a long and interesting day concluded with a conference dinner in downtown Berlin.
I am grateful to Alun Morgan for allowing me to use his photographs.
Day 2 of the conference is covered here.
Based in the UK, Pete Starkey is technical editor for I-Connect007. He has more than 30 years experience in the PCB industry, with a background in process development, technical service and technical sales.