Changing circumstances – new possibilities", The EIPC Spring Conference 2003

Citation

Goosey, M. and Starkey, P. (2004), "Changing circumstances – new possibilities", The EIPC Spring Conference 2003", Circuit World, Vol. 30 No. 1. https://doi.org/10.1108/cw.2004.21730aac.001

"Changing circumstances – new possibilities", The EIPC Spring Conference 2003

"Changing circumstances – new possibilities", The EIPC Spring Conference 2003, Top Hotel, Prague, Czech Republic

Keywords: EIPC, Conference, Printed circuit boards

About 100 delegates enjoyed a comprehensive, highly informative and interactive programme of 20 presentations over 2 days at the Top Hotel on the outskirts of Prague. EIPC President Paul Waldner suggested in his opening remarks that, if the fortunes of the European PCB industry should show signs of improvement, then future events might be held nearer to the centre of the city! (Plate 1).

Plate 1 Prague was the setting of this year's conference

Paul commented that, in the case of his own company, "changing circumstances" were "not changing fast enough" and that his business was getting accustomed to living with less, hoping for more, and waiting it out. Changes in the market had driven changes in his business philosophy, becoming less reliant on machine sales, being more responsive, supplying a wider range of products and services, and generally being more humble, more flexible and a better listener.

He reminded the audience that the room was full of people who knew things which each other did not know, so attendees should make the most of the opportunity to talk to people – "what they know can help you" – and the delegates responded positively to his suggestion. It was important to listen! Paul also thanked the EIPC staff for their hard work in organising the Spring conference.

EIPC Technical Director Michael Weinhold, who had done a magnificent job of putting together the conference programme and preparing the proceedings, welcomed delegates and acknowledged the support and generosity of the sponsoring companies. He explained the philosophy of EIPC and urged the audience to recognise the trends that impact upon PCB fabrication in Europe, to stay focused and to take best advantage of the breadth of services offered by EIPC. Michael said that in 2001 there were 488 PCB producers in Europe and he emphasized that the EIPC supported all countries in Europe. He also highlighted some of the issues that the PCB industry in Europe had to face in the near future; these included changes in device packaging, and the move to lead-free assembly and halogen-free laminates. Possible reliability issues with lead-free electronics were mentioned, as was the inexorable move to finer pitch on device packages. A pitch of 0.5 mm was common and 0.4 mm would be increasingly used next year. It would be important to understand the design implications from these finer pitches if the desired reliability was to be achieved. Michael also highlighted some of the differences in technological approach between European companies and those in the Far East. Via filling was used as an example, since this is widely done in the Far East, but not very common yet in Europe. He concluded by saying that the future industry development programme was reflected in the topics to be covered in the EIPC conference.

Michael's introduction was followed by Walt Custer's overview of the World PCB market and outlook. As ever, his statistics were comprehensive, accurate and up-to-the-minute, his analysis was as wise and meaningful as we have come to expect, and his humorous interludes sharp and entertaining. Walt reminded the audience not to confuse the temporary downturn in some key electronic end markets with the "Asian Shift"; the events overlapped, but were different. In the 2 years from 2000 to 2002 the global PCB industry had dropped in value by 25 per cent (from $42.6 billion to $31.1 billion). Global electronic equipment production had peaked in 2002 and experienced a migration to the Far East and Eastern Europe. One piece of relatively good news was that inventories had been largely reduced and some order rates were even picking up slightly. Walt also highlighted that the state of the industry varied significantly from sector to sector with the automotive industry performing relatively well with some evidence of increasing demand. The communications sector had shown a big decline although the personal computer market was recovering slightly. Current long-term views continued to be negatively coloured by the current recession, but new growth could come from unexpected sources and some recovery appeared to be starting in the semiconductor testing and equipment sector. About 65 per cent of the global PCB production was now focussed in the Far East with Ibeden being the largest producer; its production was valued at $985 million. Walt gave figures showing that Germany was the largest PCB producing country in Europe and the UK had slipped into fourth position and France was fifth.

Brewster Barclay, Marketing Director of Orbotech SA, moderated the opening session of three papers on the subject of "Front End and Phototools".

The first paper was given by David Grau, CAM Business Manager for Orbotech, who described the difficulties faced by fabricators in coping with ever-increasing numbers of orders, the consequent shift of the traditional production-floor bottleneck into the front-end office, and the critical need for efficient communication of information between departments. Orbotech's proposed solution was a single centralised database containing all of the OEM, MRP and ODB++ information, accessible to individual departments through application software specific to their individual needs. David's paper emphasized that even in a difficult business environment there were ways to improve by focusing on the key constraints that prevent companies from doing better.

Eric Janssens, Marketing Manager PCB for Agfa Gevaert, explained the practical aspects of silver halide photo-tooling film, with particular emphasis on the factors that influence dimensional stability. He discussed the characteristics that were required of a modern phototool and emphasized the importance of dimensional stability. Modern film was a remarkably complex multi-layered material based on polyester with several layers of other coated materials. Thermal expansion mismatch issues were discussed and Eric illustrated how the thermal coefficients of the various materials used in film construction varied. He also detailed the effects of humidity on material expansion; diazo materials typically exhibited a 9 microns/m dimension change for every one percentage point change in the relative humidity, while for polyester film the figure was 8 microns/m. Best practices that should be used to minimise these effects were discussed in detail and simple procedures such as storing artwork in its original packaging were recommended. Monitoring changes in temperature and relative humidity was also basic good practice.

Although a phototool can be subject to a variety of reversible and non-reversible changes, with an understanding of its characteristics, proper control of process parameters and observance of some clearly defined rules of best practice, there was no reason why silver halide film should not continue to satisfy the increasingly critical demands of the industry.

Giles Branthwaite, Business Development Manager for Avecia concluded this session by reviewing the technology of drop-on-demand ink- jet printing and described how techniques had been developed for PCB applications using industrial piezo-electric print heads. Ink-jet printing offered many nominal advantages over traditional imaging methods, in simplification of the process, flexibility, and saving of floor space. Printers capable of dispensing drop sizes of 10 picolitres represented the current state-of-the-art, but machines dispensing 6 picolitres would be available later in 2003. There were also environmental benefits. Legend and solder mask printing machines were already available, primary imaging was at an advanced stage of development, and direct-to-metal applications for conductive tracks and embedded components were seen as market opportunities. Legend ink printers typically cost around 150-210 k euros and took 18-20 s to print an 18×24 inch board. Microdeposition techniques could also be used in the manufacture of organic light emitting diode structures as well as for depositing proteins and DNA. Giles also stated that ink-jet printing could be used in embedded passive component formation both as a potential rework tool and also to avoid laser trimming.

Rudiger Schultz (Plate 2) introduced the second session, entitled "Reliability, HDI and Signal Speed".

Plate 2 Rudiger Schulz (left), Martin Bayes (2nd left) and other speakers

Roland Menzel, Applications Manager for DuPont's Thermount, discussed substrates for higher solder joint reliability and described how, with lead-free soldering in prospect, and as interconnection density increases and component packages become larger and less tolerant of stresses resulting from thermal expansion mis- match, a better understanding of material characteristics enables the PCB designer to specify suitable substrates which fundamentally improve product reliability without significant cost penalties. Roland stated that the silicon in a chip scale package now typically occupied around 80 per cent or more of the area. The work reported in the presentation was an investigation of the typical defects found at the solder ball and surface interface caused by thermo mechanical stress and strain effects encountered during extended thermal cycling of six different types of printed circuit board constructions with both FR4 and Thermount substrates. The testing was based on 27 different finite element nodes with up to 180,000 nodes being conducted on 0.8 and 0.5 mm pitch. When the finite element modelling results correlated with practical experience it was found that 0.5 mm pitch packages increased the stress to the solder by 50 per cent compared to 0.8 mm pitch.

Continuing the theme of non-woven aramid substrates, Michael Leclercq, Director of Marketing and Technical Service with Arlon, talked about "green" materials, where conventional halogen and antimony flame retardants had been replaced by environmentally acceptable alternatives without sacrificing physical or electrical properties. Indeed, certain characteristics, for example CAF resistance, were improved. Michael discussed the properties of non-woven Aramid reinforced laminates and highlighted the benefits imparted by the negative thermal coefficient of expansion coefficient of Aramid. Laminates typically had in plane CTEs of between 8 and 9 ppm per °C as well as a relatively low dielectric constant. They were also reported to be laser drillable and gave improved drill life for mechanical drilling. He then went on to discuss flame retardancy mechanisms and the move to halogen-free laminates.

Bart van Laere, from Rogers Corporation, then gave a presentation entitled "Emerging Applications and Processes for Liquid Crystal Polymer (LCP) Circuit Materials". LCPs were thermoplastic aromatic polyesters which display excellent high-frequency electrical characteristics, very low moisture absorption and natural flame- retardancy. Several PCB fabricators and process suppliers were co-operating in the development of applications and the optimisation of processing parameters. There were two main families of LCP, the Lytropic materials such as Kevlar and Nomex and the thermotropic materials which develop their crystallinity in response to heating. It is this latter class of compound that tends to exhibit the exceptional high-frequency electrical properties and low moisture absorption that makes them useful for PCB applications.

Dr Martin Bayes (Plate 3), a Research Fellow with the Shipley Company in the USA, gave a detailed presentation of how conductor surface condition affects signal integrity at gigahertz frequencies. He described how modelling and testing techniques had been developed in collaboration with the Rogers Corporation, to measure and compare the performance of a number of surface finishes, foil treatments and inner-layer adhesion-promotion processes. Martin showed how an existing industry standard dielectric test method could be simply modified to allow measurement of conductor surface resistivity relative to a reference conductor at frequencies up to 14 GHz. Preliminary results using this technique demonstrated the ability to quantitatively measure the effects of both the nature and thickness of surface finishes and surface roughness of PCB foil surfaces on conductor surface resistivity. Interestingly, it was also reported that inner layer adhesion promotion processes applied to a copper foil surface had almost no effect on the relative surface resistivity.

Plate 3 Martin Bayes

Stefano Oggioni, Development Manager at IBM EIAC, analysed the impacts of manufacturing process tolerances on the high- speed signal transmission characteristics of the materials used to build organic laminate chip carriers, using data from electromagnetic simulation. His colleague, Mauro Spreafico, explained some of the techniques used for simulation and measurement, and how these related to various practical transmission line configurations. Work using an additive pattern plating process was described which gave almost square shaped lines rather the more trapezoidal shape typically produced. The work reported had enabled a better understanding of the real effects caused by different manufacturing tolerances on line impedance control. Impedance control was described as being a potentially very expensive requirement when coupled with miniaturisation and excessive performance targets. It was important to understand that line impedance control is relevant, but not the only "need" to achieve high-speed performance. Also, a wiring strategy needed to take into account the different effects of process tolerances and different transmission line structures.

Brewster Barclay of Orbotech opened the second day by welcoming back those delegates who had survived the festivities of the previous evening in downtown Prague at "U Fleku", where Paul Waldner had revealed yet another dimension to his extensive repertoire of skills by performing amazing conjuring tricks with nothing up his sleeves.

Joachim Zimmerman introduced the first session and Michael Krapp, responsible for process engineering at Robert Bosch, gave an insight into future demands which would be placed upon PCBs in the rapidly growing automotive electronics sector. Circuit board assemblies would inevitably become increasingly complex and would have to endure high temperatures, rapid changes in temperature as well as shock and vibration, and show total reliability over 15 years of service life, whilst remaining cost-competitive, environmentally acceptable and recyclable. Michael highlighted the share electronics has of the total costs of a vehicle and he noted that 90 per cent of the innovations in a car are in electronics and software. This year's introduction of the 60 gramme per vehicle lead recycling threshold, as part of the End of Life Vehicles Directive, was also noted. In automotive electronics the on board temperatures can be as high as 130-140°C and this is very close to the Tg of FR4 type laminates. The need for new higher Tg laminates and more ductile copper was discussed. The demands on automotive electronics were growing and they would have to be halogen-free, lead-free with good thermal cycling performance and yet cost competitive.

Plate 4 Tarja Rapala-Virtanen of Aspocomp

Tarja Rapala-Virtanen (Plate 4), Development Director at Aspocomp, Salo, Finland reviewed the status and trends in printed circuits with embedded components, which were seen as a natural progression beyond established HDI technologies. The challenges had been identified, and attention was being focused on applications where benefits would outweigh cost and risk, with fair consideration of the realities of practical implementation by the PCB fabricator. Tarja discussed the key benefits of embedding passives such as improved reliability, enhanced electrical performance, increased throughput (fewer components to assemble) and reduced cost. She then went on to present the results of an evaluation of three different techniques and seven materials. Thin film materials based on various metal compositions such as Ni, NiCr, Pt and NiCrAlSi were described and these had been found to give good tolerances, without the need for trimming, via a process that was easy to control. Other approaches described by Tarja included those using ceramic pastes, carbon printing and electrochemical deposition of nickel phosphorus films. Although there were several material routes that were being commercialised for the production of embedded passive components there were also key infrastructural changes necessary before embedded passive technology would be widely adopted. These focussed on design, CAD, CAM, AOI and electrical testing. There was a need to make the technology easier to adopt for both designers and fabricators in order to encourage its use. Co-operation across the whole supply chain was vital. Aspocomp was working in a collaborative project with Elcoteq and was also involved with the IPC committees working on standards development for embedded passives.

Michael Schumacher, President of Cascade Consulting, gave an inspirational presentation on the subject of "pushing your business past the tipping point of success," and introduced terms such as the law of the few, the stickiness factor, and the broken windows theory into a PCB manufacturing context. He predicted that the future success of the western-world's printed circuit industry would depend on small organisations where people interacted, communicated, shared information through a "group transactive memory", and cared about the details. Such companies knew how to "act small", how to quickly adapt and respond to change, and how to hang together through hard times. Michael gave examples of social epidemics, where ideas and social behaviour spread fast like a virus. The tipping point was the point at which the concept begins to spread rapidly through a society. Companies that had no more than 150 employees tended to exhibit group memories.

In the second session, introduced by Peter Starkey, Stephen Bray, the senior engineer at Prestwick Circuits, described the philosophies and management techniques that had been successfully applied in bringing about changes which had transformed Prestwick into a lean, fit and agile manufacturing company. They were enabling the company to compete successfully in the automotive market, and to achieve specific goals in cost, quality and reliability. Prestwick regarded its customers as partners, because goals, objectives and roadmaps were shared. Of the available capacity 53 per cent was supplied to its top three customers. Stephen stated that although it was increasingly difficult to compete with Asian labour rates, the company could continue to compete by adding value to the products and services it offered.

Dr Dieter Meier, R&D Project Manager at LPKF Laser reviewed the status and trends in laser technologies for PCB applications, and introduced a UV mask projection process for structuring thin metallic layers, which could be used as a cost- effective means of fine-line patterning down to 15 micron lines and spaces. A number of new applications for this laser technology were introduced, including an all-dry inner layer process known as laser direct circuitisation (LDC). LDC uses a specially developed etch resistant organic film which is deposited as 1 micron thick film by a simple dipping process onto the copper surface. The laser ablation of electrically conductive organic polymers such as those that are used in some direct plate processes was described. With the increase in ablation speed of each generation of new lasers the number of applications for them in the PCB manufacturing is set to grow further.

Robin Taylor (Plate 5), Atotech's Marketing Manager for Electronics Products, reviewed the characteristics and limitations of established copper surface treatments for multilayer bonding, and described a new oxide replacement system which combined the benefits of a peroxide- sulphuric inter-granular etch with a white immersion tin. This new process yielded consistently high bond strengths that were maintained through the multiple lamination cycles increasingly associated with complex HDI substrates.

Plate 5 L-R: Robin Taylor, Stephen Bray, Peter Starkey, Dieter Meier

In the final session, introduced by Martin Goosey of Shipley Europe Ltd, the emphasis was on new technologies and related work aimed at addressing environmental issues.

Don Cullen, Director of OEM and Assembly Applications at MacDermid, considering final finishes for lead-free soldering applications, commented that although HASL was still the predominant finish worldwide, its market share was becoming rapidly eroded by alternatives. He reviewed the whole range of contemporary finishes, explaining their relative benefits and limitations. Immersion silver was becoming widely specified and represented 8 per cent of the world market.

Neil Patton, Atotech's Product Manager for PTH processes, described an environmentally friendly electroless copper where hypophosphite had been substituted for formaldehyde, and citrate was employed as a biodegradable complexant. The process relied on the presence of small amounts of co-deposited nickel to promote the autocatalytic reaction, and produced a very fine grain deposit that offered technical, as well as environmental, benefits.

Dr Manfred Suppa, Manager of R&D with Lackwerke Peters, continued on the environmental theme by examining the ecological issues associated with the processing solvents and solutions used in primary resists, solder masks and conformal coatings, and explaining the characteristics and advantages of solvent-free lacquers. He also pointed out some of the anomalies in the legislation regarding solvents and flame retardants. An interesting irony was that environmentally friendly "green" solder masks tended to be coloured blue, to emphasise their halogen-free nature.

Martin Goosey described an investigation that had been carried out by Shipley into developed and emerging recycling technologies for the treatment of end-of-life printed circuit boards. The project had received UK Government funding through the Sustainable Technology Initiative. It had been concluded that no single treatment technique would handle all scrap PCBs, and that an integrated hierarchy of approaches, including disassembly, mechanical and hydrometallurgical methodologies, would be needed. (A paper outlining the findings of this work appeared in Circuit World, Vol. 29 No. 3.)

Jason Turner of Napier University made the final presentation of the programme, on the subject of improving manufacturing efficiency by design. The University had collaborated with a design-and-assembly house to determine the effect of automating the "Design for excellence" analysis process using a knowledge-based system, with the objective of improving the quality and speed of analysis, and concluded that although some time benefits were gained, these were at the expense of the amount of work needed to input the data.

Paul Waldner wrapped up the proceedings with a happy smile. The atmosphere in the conference room was positive and cheerful (Plate 6). There may not have been any great expectation of a miraculous recovery, but there was certainly none of the feeling of doom and gloom to which we have become accustomed over the last couple of years.

Plate 6 Conference delegates networking during coffee

The 2003 EIPC Conference was a resounding success and the whole event went superbly smoothly. The organisation and management were faultless, and the efforts of Kirsten and Sonja of the EIPC cannot be praised too highly. We look forward to the next one in Cannes during February 2004.

This conference review is an extended version of a report written by Pete Starkey for the EIPC and the authors gratefully acknowledge the permission of the EIPC for its use as the basis of this review. The proceedings of this conference are available from the EIPC and details can be obtained by e-mail at info@eipc.org or visit www.eipc.org

Martin Goosey and Peter StarkeyMay 2003