Citation
Goosey, M. (2009), "EIPC Summer Conference 2009, 18-19 June 2009", Soldering & Surface Mount Technology, Vol. 21 No. 4. https://doi.org/10.1108/ssmt.2009.21921dac.005
Publisher
:Emerald Group Publishing Limited
Copyright © 2009, Emerald Group Publishing Limited
EIPC Summer Conference 2009, 18-19 June 2009
Article Type: Conferences and exhibitions From: Soldering & Surface Mount Technology, Volume 21, Issue 4
Hotel Eggerwirt, St Michael im Lungau, Austria
The EIPC’s 2009 summer conference was held in the picturesque Austrian town of St Michael im Lungau, which was surrounded by tall, snow-capped mountains. The conference itself spanned two days with a programme of 24 presentations, panel discussion sessions and a visit to the nearby IMPEX Leiterplatten factory.
The conference began with a welcome by the EIPC’s Chairman, Rex Rosario of Graphic plc, who gave an overview of the conference programme (Figure 3). He also gave a brief review of the state of the PCB industry and mentioned some of the recently published positive predictions for the coming years. Rex also stated that the key subject of the day was “technology transfer” and emphasised how this approach should be of use to the PCB manufacturing industry. He also suggested the potential benefits of collaboration and mooted the possibility of the European PCB industry sharing its R&D activities.
Dr Konrad Wundt of the EIPC then introduced the conference’s keynote speaker, Walt Custer of Custer Consulting. Walt gave another of his extremely detailed presentations on the current business outlook for the global electronics industry. He began by discussing the recession and stating that the industry was now believed to have either bottomed out or was close to doing so. The UK had seen negative growth of 12.3 per cent over the last year, with Europe, overall, being ~20 per cent down. There were a number of indices showing that the worst had probably passed and it had been reported that the G8’s finance ministers were now preparing for global growth. Walt then went on to show that inventory levels across the electronics industry and inventory relative to sales were now increasing (albeit at low levels). He also highlighted the valuable data that was available from “Eurostat”, which published information on electronic production by product type. In Europe, medical and military electronics were virtually the only sectors currently showing growth. The electronics industry had also been hit hard by the large drop in automobile manufacturing. Interestingly, there had been significant growth in the production of “netbook” computers, although they were typically low in price, so the overall financial benefits for manufacturers were not large. However, overall, semiconductor manufacturing was still very much depressed. In terms of the major EMS companies, they had also largely shown negative growth throughout 2008. For 2008, total PCB production was valued at around $49 billion with Nippon Mektron being the world’s largest PCB fabricator. Europe was estimated to now have around 240 PCB fabricators, with the largest producing country being Germany, which had 38 per cent of European production. AT&S was the largest European board producer in 2008. The forecast for electronic equipment showed production growing globally by 5 per cent in 2010, although there would be significant variations from country to country.
The conference then moved on to a series of themed sessions and the first of these, which was chaired by Konrad Wundt, was entitled “Business models for PCB success in Europe”. The first paper on strategies for survival was given by Giacomo Angeloni of Somacis in Italy. The survival strategy adopted by Somacis had involved partnering with Graphic in the UK and the establishment of some production in China via a new plant called DSG in Dongguan City. In Europe, Somacis was the second most profitable PCB manufacturer and a new plant had also recently been set up in Italy with some funding support from the European Commission.
Michael Weinhold of the EIPC gave a presentation on “How to get business back from China”. Michael began by showing some of the recent good news that had been reported by the PCB industry. However, European PCB production had continued to fall by value and, for 2008, it was less than half of the 2000 figure. He then discussed the effect of exchange rates between China and Europe, which was now making Chinese PCBs more expensive. Europe would always retain certain types of circuit board production such as high-end military and medical boards, as well as fast turnaround and special technology boards and development work. Michael reviewed the reasons influencing the choices between sourcing boards from Europe and China; these included quality, cost, technology, delivery time and after-sales service/design support. Most European PCB fabrication companies had the capability to get back into the PCB supply chain, especially if they could become a resource for their customers and could add non-monetary value to the PCBs that would help them to stay more competitive, for example, by maintaining communication on all levels, from engineering design to quality and management. European PCB fabricators had many advantages such as no currency fluctuations, short distance to customers, no language issues and good knowledge of standards. Michael also stated that it was important to understand costs, to know the cost structure of competitors in both Europe and Asia and to know the costs of selling. The presentation concluded with a discussion of the opportunities available from the use of new technologies such as embedded capacitors.
The final presentation of the first session was by Ivan Ho of TopNotch Technology Ltd, Hong Kong and was on “A new business model/thinking for European PCB producers”. Ivan introduced the key business issues currently impacting on PCB fabricators; these included sales revenue reductions, customer base erosion and customers going offshore. European producers needed to adopt new ways of thinking and new technology approaches such as the use of thick copper, hi-layer count back planes, rigid-flex, HDI and mixed materials, etc. Ivan then gave examples of some new Chinese PCB facilities including one based in the PCB Industrial Park in Chongqing which offered HDI, IC substrate boards and prototyping. Another company, SCC, had 2,200 employees and sales of $150 million. Ivan advocated working with Chinese suppliers to form alliances and to offer a wider range of products, so that market share and customer base could be expanded. He concluded by showing a map of China with the locations of the PCB manufacturers and it was estimated that at least 1,000 companies were located in southern China. It was estimated that there could be as many as 3,000 fabricators across the whole of China. The session finished with a panel discussion involving all the speakers from the first session.
The second session of the conference was on advances in materials and was chaired by Giacomo Angelonin of Somacis. The first presentation was given by Thomas Michels of TMT Trading GmbH and was entitled “The challenge of using no-flow prepreg versus bonding sheets in rigid flex applications”. He began by asking why the industry still uses bonding sheets and said that it was largely because they had always done so. The history of bonding sheets was then discussed and in the past, these had only been available from Dupont as an acrylic sheet. However, epoxy resin-based products had also been produced to counter the price and chemical resistance constraints of acrylic bonding sheets. No flow prepregs were also developed to meet the increasingly demanding technical requirements which included the move to higher Tg materials, the main driver being the automotive industry. Data were then shown for no-flow prepreg that had been built into a 14-layer board and exposed to thermal cycling. The IPC test method, IPC 2.3.17.2, was used to ensure flow measurements were meaningful. Properties of bonding sheets and no-flow prepreg were then compared and contrasted. The no-flow prepreg generally had a lower flow, better dielectric strength and enhanced through hole reliability. In summary, it was concluded that using no-flow prepreg gave the opportunity to produce more cost-effective boards than with the use of bonding sheets.
The next paper was on “Next generation PCB laminate requirements for high speed digital applications” and was given by Young Gao, market development manager of Rogers Corporation, USA. The trends in high-speed data transmission were introduced and it was predicted that while bandwidth demand would grow exponentially, there would also be continuing demand for reduced BGA pitches and operating voltages. These lead to increasing demand for suitable laminate materials capable of performing satisfactorily at high frequencies and accommodating high numbers of I/Os per unit area, e.g. more than 600 in−2 in 2009. A key concern for high-frequency operations was signal degradation during transmission and minimisation of bit error rates was increasingly important. Key laminate factors were conductor and dielectric loss and data were shown giving fractional conductor loss versus frequency out to 100 GHz for a commercial laminate. Control of copper roughness was also increasingly important. There were also concerns about the local dielectric constant uniformity due to compositional variations in typical laminates such as FR4 and an example was shown of the impact on signal integrity of such variations in Dk. One solution was to use a flat glass to reduce weave impact on Dk variation. The implications for MLB boards were then discussed, along with other considerations such as lead-free capability, reworkability and operation in extreme environmental conditions. Other material requirements included higher Tg and reduced thermal expansion and an OEM backplane roadmap for 2010 was shown. In his summary, Young reiterated that the need for greater bandwidth and high-density routing was pushing demand for higher performance laminates.
Albert Angstenberger of Taconic’s Advanced Dielectric Division gave a talk on “PTFE composites designed for excellence in high-frequency/high-speed applications”. PTFE laminates offered outstanding dielectric properties in high-frequency applications and Albert gave an overview of PTFE’s chemistry and properties. By varying the amounts of woven glass or ceramic in the product it was possible to vary the Dk from just above 2.0 to around 10.0. Laminates were produced with metals such as copper, aluminium and brass, in order to give enhanced thermal conductivity. Processing of PTFE laminates typically needed special attention, especially in the drilling, desmear and metal plating operations. Physical properties of PTFE laminates were shown, e.g. thermal expansion was typically very low up to 300°C and boards could survive multiple soldering cycles. Thermosonic wire bonding onto PTFE boards was typically capable of giving better results than on FR4. PTFE was also very stable to environmental exposure and could be used in mixed material multilayer structures.
The final presentation of the session was given by Thomas Apeldorn of the University of Bayreuth and was called “Innovative substrates for PCBs based on thermoplastic polymers”. Thomas began by explaining why thermoplastic substrates were used in some applications. Key positive factors were said to include low-dissipation factors, lower costs compared to conventional high-frequency substrates and high-operational temperatures. Methods of fabricating thermoplastic PCB substrates were compared and contrasted with conventional fabrication routes and it was shown that it was possible to remove one or two processing steps. The latest thermoplastic substrates could be inherently flame retarded and had the ability to be thermally shaped. They could also be recycled. Techniques such as foaming of the thermoplastics, as well as blending and the incorporation of specific fillers had been investigated in order to tailor the substrate properties. The properties of these thermoplastic substrates were compared to those of standard substrate materials. The so-called HTT foamed high-temperature thermoplastic substrate manufacturing process was described and this involved gas injection. The dielectric constant and dissipation factors were then shown. A material with an isotropic thermal expansion coefficient had also been developed. This had a CTE of 50 ppm/K and offered a two-step lamination process. For the “LUVO” and “HT” board types, the dielectric constant was relatively low (∼4.0) and remained almost level out to frequencies of 1.2 GHz. These materials could also be shaped but further development work was needed before series production could begin.
The first afternoon session was on “Advanced enabling technologies” and was chaired by Konrad Wundt of the EIPC. The first presentation was given by Martin Goosey of the Innovative Electronics Manufacturing Research Centre (IeMRC) based at Loughborough in the UK (Figure 4). Martin gave an introduction to the IeMRC and what it was seeking to achieve. He then went on to give an introductory overview of three of the IeMRC’s projects that were related to PCB and interconnect applications. These examples included the IeMRC’s flagship project to integrate optical wave-guides into conventional PCBs. He also outlined the printed electronics work being undertaken by Brunel University which, in addition to the printing of conductors, had also moved on to the deposition of components, batteries and displays. The third example highlighted work being undertaken at Coventry University to develop ultrasonically assisted methods for texturing materials used in electronics assembly, e.g. PCB laminates. By using enhanced ultrasonic techniques it was possible to texture materials at room temperature, using much less aggressive chemicals than those conventionally used.
4 Martin Goosey spoke about the IeMRC
The second presentation was given by Markus Leitgeb of AT&S (Figure 5) and his presentation was called “2.5D technology platform – a novel approach to rigid flex and structural applications”. He began by describing the future roadmap and the need to route two lines between the pads of a 400 μm pitch ball grid array pad followed by the need to provide one track between a 300 μm pitch BGA. The basic principle of the 2.5D technology platform was described and this used a standard structured core which was then screen printed with a release layer that enabled subsequent separation and removal of part of the processed board. The advantage of this approach was that it enabled the use of standard base materials and gave much better accuracy in depth control, no cutting process is needed and boards are rigid and flat until the end of the process line. Examples of test boards with components mounted in board cavities were shown and these had been subjected to testing which had demonstrated their excellent reliability. An advanced HDI rigid-flex PCB concept using a combination of polyimide and FR4 was also described. Markus concluded by showing the cost reductions that were possible with the 2.5D technology and in the example given a saving of 15 per cent had been achieved.
Michael Weinhold then spoke about the “Situation on PCBs with embedded components”. The technology for embedding components into PCBs had been around in Europe since 1996 but had not yet been fully adopted. The situation today was that a large amount of components had now been developed that could be embedded into a PCB. Examples made by Schweizer were shown and, in one case, the silicon could be introduced into the middle of the board. The European Commission-supported project “Hermes” was also mentioned, where several layers of silicon had been incorporated inside the PCB. Murata had developed a technology for embedding multiplayer capacitors into a board, which gave better performance because of the low noise capability. The components could be soldered into the board or connected via a plating process. There were now many companies working to embed components into boards and they included IZM, NXP, IMEC, Murata, Infineon and the Fraunhofer Institute. The 3M had an embedded capacitor material which had successfully been used to produce a large number of production boards in the Far East. A European company working in this area was Imbera who had embedded ICs and certain passives within the substrate. The future outlook for embedded components was promising since the technology could offer advantages such as reduced cost through miniaturisation, improved performance and increased reliability.
The fourth speaker of the session was Karl Heinz Ognibeni of Sun Chemical, who discussed “New materials for flex and flex/rigid flex circuitry”. The first new materials covered were fast exposure flexible LDI solder masks that could be used in flex rigid production. The reliability of the materials had been evaluated with a number of common solderable finishes, including nickel–gold and tin. The second part of the presentation focussed on new coverlay replacement materials and examples of the manpower and materials costs savings that had been achieved in real applications were detailed.
Dirk Bäcker from LPKF then gave a presentation called “Laser applications beyond the limits” which focussed on rapid prototyping of PCBs, production and assembly and MIDs. He began by describing the types of laser-based equipment used for PCB prototyping and compared the performance of UV and CO2 lasers. UV lasers needed much less cutting space than CO2 lasers (20 μm versus 120-240 μm). UV lasers also do not give carbonisation or delamination. LPKF’s customers were also using UV lasers because of their high precision; they were finding use in coverlay cutting, because it was found to be better than punching, and in cutting rigid flex boards. Another key advantage was that there was no redeposition of debris after cutting. Drilling of microvias was also described along with de-panelling.
The final presentation of the first afternoon session was by Stefan Kunz of Schmoll Maschinen and this was on “High accuracy routing”. Contour routing accuracy was becoming more important and key influencing factors were tool tolerances, tool wear, stack height and the type of routing machine. In routing machines, linear motors could provide higher accuracy, especially in areas of complex routing contours such as quadrant intersections. The requirements for high precision depth routing were then described and it was stated that an accuracy of around 20 μm could be achieved.
The final session of day one on quality assurance and environmental issues was moderated by Michael Weinhold of the EIPC. The first presentation of the session was by Bill Birch of PWB Interconnect Solutions Inc. and was on “Reliability testing for microvias in printed wiring boards”. Bill began by reviewing industry trends and referred to the impact that the RoHS Directive was having in increasing the levels of stress on interconnects and thus reliability. The higher lead-free soldering temperatures were leading to increased substrate damage, often inside the board where it was not immediately visible. New techniques were thus needed to find these impacts, for example, on stacked vias. The method Bill described was known as interconnect stress testing (IST) and it utilised test coupons that contained heating and sensing circuits. The coupons were heated while the resistance was measured. Bill also discussed various types of microvia-based structures such as stacked and staggered microvias, as well as the influence of microvia shape on subsequent reliability. Coupon designs for IST were also detailed along with the physics of microvia failure. (Owing to time constraints, Bill was unable to complete his presentation and was invited back to complete it at the end of the conference, see below.)
The next presentation was by Andrew Kelly of X-Act PCB UK, who spoke on “Developing raw data into intelligent manufacturing information”. Andrew outlined the benefits of computerised systems and the ability to collect real time data. In the PCB industry the latest equipment was capable of capturing and storing such data for all batches processed. For example, the X-ray drilling process derived raw data that could be transformed into meaningful information and which helped to gain a better understanding of the drilling issues such as tolerance. Andrew stated that the best implementation of a knowledge-based system should appear to be simple and provide a good return on investment.
The third presentation of the session was titled “An energy efficient final finish for PCBs” and it was given by Melanie Rischka of Ormecon/Enthone (Figure 6). Melanie began by showing an example of an “organic metal” molecule which was basically a conducting polymer with the properties a noble metal and similar to silver. It was also a nanometal with a 10 nm particle size and it behaved as a catalyst. The organic nanometal also prevented oxidation of metals such as copper. It was used in a revolutionary surface finish of which 90 per cent of the deposited later was organic. The organic metal deposition process was short and operated at a relatively low temperature. An environmental impact assessment of the new process had also been made and it was compared to conventional HASL. Compared to ENIG, a 95 per cent energy saving was possible along with savings in water consumption. Various other studies had also been conducted and the OrmeSTAR process had a number of confirmed benefits over conventional surface finishing processes, e.g. its green house potential was lower than for all other finishes, including OSP.
The final speaker of the session was Norbert Ferner of Impex Leiterplatten GmbH and he spoke on the subject of “Energy efficiency in the drill room”. Norbert described the steps that had been taken to reduce energy consumption in the Impex factory. Ground water was used in the machine cooling system; it was returned to ground 5° warmer then when pumped out of the ground. Waste heat from the compressors, exhausters and machines was used to heat a 30,000 L water tank to 80°C. This was used for the under floor heating and the radiators. As a result, the energy cost of operating 90 spindles was the same as was previously used to run 35 spindles.
The first session on the second day of the conference had a focus on “How to improve efficiency in drilling” and was chaired by Giacomo Angeloni of Somacis. Uwe Lenz of Ernst Lenz Maschinenbau GmbH gave the first presentation on “Efficiency in drilling” and he began by stating that in Europe most PCB production was now typically prototyping and relatively low volume. This meant that there was a need for more flexible drilling machines that could both drill and route. These also needed to have a controlled depth drilling capability and broken bit detection. Examples of mechanically drilled blind vias were shown both before and after plating and it was claimed that they had better performance than laser drilled vias. Being able to produce microvias on the same drilling machine offered significant efficiency gains. The use of a special tapered tool for drilling microvoias was also described. Uwe then moved on to discuss drilling machines that were more suitable for high-volume production and efforts that had been made to speed up the drilling process. It was also important that the drilling machines had a short set up time.
The second paper was from Jason Marsh of Kyocera and his presentation was called “Advanced repoint technology, reduce costs without comprising quality”. Repointing of tools could offer significant cost savings without compromising quality and performance. In China, his company was manually repointing 5 million tools/month. However, repointing automatically could also offer some key advantages such as consistency in inspection, i.e. AOI was more consistent than using manual inspection, which was limited to 0.20 mm resolution and subject to operator fatigue, etc. Data was then given which showed the costs per hole and cost savings available by using repointed drills. Automated control of stock removal was also much more accurate and controllable than with manual systems. In order to automate the optical tool inspection process it had been necessary to change the inspection illumination wavelength and to develop new light emitting diodes; narrow bandwidth blue LEDs gave improved results. Using repointed drill bits could save up to 70 per cent on a cost per hole basis. The presentation concluded with a short video showing a working drill repointing machine.
The final presentation of this session was by Martin Stumpp of HPTec GmbH and was on “Cost reduction through innovation – from the viewpoint of a tool supplier”. Martin began by outlining the principles for making cost calculations on the drilling process and the factors that needed to be included. Key cost factors related to the machine, the tools and the operator. An example cost calculation was shown which compared the costs of drilling 0.4-0.2 mm holes. For example, the move to smaller holes meant reduced drill lifetimes and reduced stack heights, which led to increased costs. Moving from FR4 to a ceramic PCB required similar changes and the costs increased by a factor of four. There were, however, a number of variable costs which could be influenced. For example, drill lifetime extension via the use of high-performance tools could offer savings, as could drill repointing. By increasing the bit in feed and retracting speeds during drilling the process costs could be reduced by 16 per cent. Increasing the stack height from 2 to 3 could reduce the costs by 20 per cent. The opportunities for savings were then ranked and it was shown that stack height increases offered the biggest savings. Martin then focussed on the topic of tool repointing and discussed the advantages and disadvantages. After each repointing the bit web thickness increased and thus there was a reduced cutting edge which eventually led to increased breakage. Changes in the drill design to give a multiple web taper could, however, give better reliability, i.e. reduced breakage in repointed tools. The final part of the presentation focussed on the possibility of coating tools with diamond or by PVD coating. These coatings were around 1 μm thick and gave reductions in tool wear, leading to a two or three times increase in lifetime. It was predicted that in the next two years there would be many coated tools available.
The final session of the conference also had a focus on efficiency improvements in drilling and it was again moderated by Michael Weinhold of the EIPC. The session began with a talk by Stephen Kurz of Schmoll Maschinen GmbH and was on “Influences on drill hole accuracy/quality in PCBs”. There were a number of variables that influenced the drilling process and it was only the creation of optimum conditions that ensured drilling quality was achieved that could satisfy all demands. These variables and factors were then introduced and they included the machine, the hole, the tool, the drilling parameters, the operating environment and the material being drilled. The first example discussed covered materials including the entry material, which could cause alignment problems if the surface was scratched. Heavy scratching and debris on the top side of the aluminium entry material led to poor accuracy and increased drill breakage. The back up board and stacking process also had an impact. Stephen then discussed the optimum drilling speed for specific materials and hole sizes, e.g. the drilling speed for a 0.05 mm hole in FR4 needed to be 950 k rpm. Preventative maintenance could help maintain drilling efficiency and machines should be kept clean and properly serviced. The pressure foot was also a potential cause of poor accuracy and a high-vacuum force could lift the entry material leading to contamination, mis-registration and drill breakage.
The second presentation was called “One step X-ray drilling/routing process” and it was given by Pietro Zulli of Pluritec in Italy. The importance of X-ray machines in multilayer PCB manufacturing was well-known and they were a key factor in the drilling process. X-ray could be used to address the problems of distortion after lamination. The X-ray optimiser will drill reference-tooling holes with reference to the fiducials. However, with non-linear distortion, it may not be possible to introduce sufficient correction. X-ray could also be used to confirm the alignment of each side of a double-sided board where this alignment was critical, e.g. where there was a connector. Pietro described a dedicated machine that provided free movement of the X-ray source under the tooling plate working area, thus allowing the detection and measurement of pads over the whole area of the panel and overcoming the limitations of conventional X-ray machines. The machine enabled the use of more fiducials and not just the four corner fiducials that were typically used. This allowed multi-zone compensation to be applied directly on the artwork, thereby leading to enhanced drilling accuracy. The machine gave improved yields, cost reductions, improved feasibility of critical panels and greater flexibility.
The final official presentation of the session, and the conference, was given by Bernhard Steiner of Impex Leiterplatten GmbH and was on “Contract drilling, quality and inspection”. Bernhard began by describing his company’s range of products and he gave examples of the types of objects that could be measured by each machine. One machine discussed in detail was the ProX3, which incorporated the QC metrology system; this could perform optical depth measuring and it was also useful for inspecting microvias as well as for measuring holes, lines and fiducials, etc. to an accuracy of 5 μm. It could scan a 500×500 mm board with 100,000 holes in less than 60 s.
Although, the last official presentation of the conference was the one above, Bill Birch was invited back to complete the presentation he began during the first part of the conference. Bill picked up where he left off by discussing Weibull analysis of 2-4 stack microvia boards tested at 190°C. There were significant variations in lifetimes with the type of stacked via and its location. Some examples of failure modes were shown including the influence of laser ablation and the presence of residue on the copper pad at the bottom of the via. Most failures were typically found at the bottom of the microvia and a good microtech of the copper was essential to give a good clean plateable surface. Poor desmear could also lead to interfacial separation and it was noted that the residue after laser ablation was more difficult to remove than standard FR4 resin. The quality of the electroless copper deposit at the bottom target pad was absolutely critical in ensuring microvia reliability. The planarisation process prior to microvia construction was also very critical and the thickness of the copper had a major impact on the connection of the microvias to the planarisation layer. Bill then discussed methods for finding the location of failed microvias and he stated that the preferred method was based on thermographic imaging. Microetching of sections of failed microvias was a useful approach, despite IPC recommendations that this was not needed. He concluded by stating that the industry really needed to start again when considering microvia reliability testing, as the established rules and methods no longer applied.
The formal conference sessions concluded at lunchtime on the second day and after lunch the delegates were able to take part in a visit to the IMPEX Leiterplatten GmbH factory, which was also located in the town of St Michael. IMPEX offered a drilling and routing service and had installed a Schmoll Cube shuttle system at its factory in 2008. The company had 15 machines with a total of 53 spindles and one module with ten single station double head machines for drilling and routing.
In summary, this was a very successful and highly interesting conference that offered the delegates a wide range of technical and business information, as well as being an excellent networking opportunity. The conference facility, hotel and location were also all excellent and the EIPC is to be congratulated for organising such a successful event. Further information about the EIPC can be found at: www.eipc.org and copies of the conference proceedings can be obtained by contacting Kirsten Westernberg, e-mail: k.westernberg@eipc.org
Martin Goosey19 June 2009