EIPC Winter Conference, Barcelona, Spain, 27-28 January 2005

Citation

Ling, J. (2005), "EIPC Winter Conference, Barcelona, Spain, 27-28 January 2005", Soldering & Surface Mount Technology, Vol. 17 No. 2. https://doi.org/10.1108/ssmt.2005.21917bac.003

EIPC Winter Conference, Barcelona, Spain, 27-28 January 2005

EIPC Winter Conference, Barcelona, Spain, 27-28 January 2005

Keywords: Electronics industry, Conferences, Printed circuits

27 January-Day 1

Welcome from Paul Waldner

A warm welcome from EIPC Chairman Paul Waldner obviated the chill of an unusually cold Barcelona. “It’s good to have everyone here”, he said, with over 100 guests filling the room.

He went on to talk about the work of EIPC, a primary function of which is to bring people together. “We shine light on trends; we have a long history of being technically orientated, both in the past and in the present, and through our offices we can bring solutions to problems, and connect members to the world”. He continued on the facts that EIPC is active in the WECC, and is in contact almost every day with other organisations, and that EIPC is developing market systems, with up-to- date information about European and world markets.

He emphasised that the Institute would like to influence government policy, and to that end there is an aim to bring in the resources to do that over the next year.

EIPC offers strong training programmes throughout Europe, with further Technical Snapshots on the agenda. There is an EIPC/CPCA Friendship Tour on offer, the Summer Conference in Stockholm, our involvement in IONMET, and the continued TechLink activity. On a final note he advised those who wanted to become involved to get themselves elected as the bi-annual election of officers is due this year.

The Key Note Speech came from Bob Shrouds, who is the Du Pont Corporate Economist, based in Wilmington, Delaware. He talked about the economic outlook for 2005; there would be growth yes, but challenges abounded. There are lots of moving points, but in the end it is all to do with averages. In real GDP percent change, overall the world is showing 3.0, Western Europe 1.9, Central and Eastern Europe 5.4, Asia 3.6, and Japan 5.7. The price of oil in real terms is as high now as it was in 1990. It is the Chinese demand that is driving prices up; once upon a time they used to be self-sufficient, but no longer. China is growing three times as fast as the US, nine times as fast as Europe. Short-term interest rates are rising, and exchange rates are of concern too. The dollar has dropped 40 percent against the Euro, and 20 percent against the Yen. The US trade deficit is now 700 million dollars, so the dollar will continue to remain under pressure, and global expansion has somewhat slowed.

In the manufacturing sectors, defence electronics in the US is up 50 percent, with telecoms flat. Semiconductors tend to lead the pattern for PCB trends, and PCBs look on the up. Projecting 5 percent growth in 2005, might back up in 2006; still growth, not a recession, but a slower picture.

Europe has to contend to China and Asia, but they will also have to contend with the emerging Europe, they are growing three times as fast. Hungary is setting the pace, with Poland, Russia and the Czech Republic hot on their heels. European manufacturing is being badly hurt by the strong Euro, and European manufacturing has slowed.

Turning to Asia, Bob said that Japan has flattened out at peak level, which is now the same level as it was in 1990. Taiwan is growing at about 5 percent, Korea about 8 percent and China at about 14 percent per annum, understandably outpacing everyone else.

Finally, Bob said that IPC projected 73.1 percent growth in Asia, 8.3 percent in other Americas, 15 percent in North America, and 10 percent in Europe. No one left the room looking shaken.

Alun Morgan looks after Operations and Engineering for Isola in Europe, and he talked about the technology outlook from his perspective, i.e. substrates with enhanced thermal properties and substrates for high frequency applications.

Alun reviewed the basic chemistries – epoxies, phenolics, polyimides, and the structure of polymers. To improve upon glass transition temperatures, they have found that the addition of some polypropylene and some polystyrene, the melting point rises to 240°C. With the advent of lead free solders attention has been given to the decomposition temperatures of laminate rather than the Tg. It is not sufficient to specify “High Tg”, as performance should be as per specification. Laminate must withstand the higher temperatures. Isothermal Gravimetry was covered and explained, Isola do have laminates with very low losses, FR4 Epoxy Dicy(andiamide) Cured Systems.

In the high-speed digital roadmap we see that beyond 5 gigabits/s we have to go into optical solutions, and here the use of very low loss Tg laminates are essential. However, these are at the top end of the price pyramid.

Dr Razvan Ene comes from Sicily, and is the MD of Synapton S.r.l. He started with a couple of questions – what do we do, and why are we still here? Any technology becomes obsolete after about 50 years, we’ve been here for 35 years and are reaching the end of our life. Aren’t we? Well, advanced semi-conductor products need PCBs, which lie somewhere between a service and a commodity. On that basis, how can you produce something that is not defined, and how can you price it? What is a PCB? Thankfully, he explained to us what it is. The historical point of view is that, in order to position yourself for the future, you need to define what you are doing. If you do not know what you are doing, you should not be here. Quite.

Dr Ene described a manufacturing industry cost model, where the principle of maximising the price performance ratio is possible. Costs¼60-70 percent, sales and operations 10-15 percent, and profit of some 3 percent. In PCB manufacturing there are two players – prototypes, and small to medium volume manufacturers. If you charge a premium for service, what will the customer pay for such service? For prototypes that is usually OK. The problem is that in the last 3 years there has been no major technology advance for PCBs, which may effect prices, it has.

Someone who does know what a circuit board is but he thought that we may not know about KSG is Dr Udo Bechtloff, who is their MD. KSG are located in Saxony, and have a reputation for being both quick and good. They only started out 7 years ago and their turnover has increased 50 percent per annum since then. How, in this PCB industry, has that been possible? Through innovation in two things – innovation in logistics, with delivery time down to 5 days, multi- layers in 7; and innovation in technology. Every day they produce 1,000 m², and there are about 100 different jobs per day, and what they do produce is standard thick copper and “Iceberg” technology. By thick copper they mean thicker than 105 μm, even up to 400 μm. Such panels are not only for the automotive industry, but increasingly finding a home in control devices, in solar technology.

Working with thick copper brings its own demands. They have to carry a large stock of materials, including a wide range of foils in different thicknesses. Etching time typically is 10-15 times longer in the etching chamber compared to normal, and the cost of intensive selective copper plating is high. Handling such hefty panels is another matter, sometimes they are tempted to price by the kg! Tracks vary between 400 μm and maximum 600 μm, with minimum spacing of 200 μm. For LPISM, curtain coating is best, spray coating is possible.

Tarja Rapala the R&D Director at Aspocomp in Finland came to discuss new materials and build-up constructions for advanced Rigid-Flex PCBs.

Why do we need rigid-flex technology? What are the drivers? Simply, more performance in less space; more functionality, better electrical performance, good dimensional stability, tighter tolerance for registration. All those things. Good thermal management and reliability (both mechanical and corrosion) are enablers for Bare Chip On Board.

She covered the subject of stacked via technology, and HDI development, bearing in mind the closer line and space requirements on thin and flexible materials with several microvia layers. It is important to reduce the number of assembly steps. Flex is dynamic, it is efficient, and in the right applications they can create cost savings for OEMs. Drawbacks of traditional rigid-flex include reliability, dimensional stability, handling, plating and it is not easy to implement HDI. Now it is all about “Snapoff Rigid Flexe™”.

Illustrating this new process, Tarja explained how one can use low-cost materials for the rigid part, how these can be linked together with one flexible layer on the surface of the panel acting as the connector. It is easy to process in a rigid PCB shop, as there is now no requirement to handle thin flex material in the wet processing lines. She showed illustrations of the production process up to eight layers. The concept comes from customers’ requests for this, they just need to bend it once to install, so it is not a dynamic process. But it does allow great freedom of design.

Dipl.-Ing. Markus Willie is the product manager at Ruwel AG. They make rigid-flex boards for the automotive industry, under the names of Multiflex and SemiFlex. There are a huge amount of electronic controls in a car, he said, but they do have to operate within the high temperature and extreme conditions in a car in which they are installed. There are huge quality requirements, for electronics mounted on the engine, near the engine, and in the engine compartment. The test concept runs from −40°C to +175°C. The specs. are demanding, and testing is over 11,000 cycles. This is the environment we have to deal with.

Flex-rigid circuits offer high reliability, with no wiring errors, lower weight and taking up less space. With Multiflex they can produce from a minimum of 2 up to 8 layers, where flexible and rigid layers are connected with plated through holes. There is an asymmetrical configuration, and a symmetrical configuration. Polyimides best, but PEN and PET can be used. The asymmetrical configuration is available at a reasonable price, but the symmetrical configuration offers better planarity due to symmetrical stack-up, is easy to use for further processing, as both outer layers are rigid, and offers higher flexible strength, high reliability during thermal shock and thermal stress.

Thermal shock reliability has six classes, TK1-TK6, which are Bosch standards. To increase thermal shock reliability, careful selection of substrate materials has to be made, considering the coefficients of thermal expansion and Young’s Modulus to reduce internal stress. Semiflex is made from FR4, with only one conductive layer possible in the bending area. Only a few bending cycles are allowed, with bend radius limited to 5 mm.

Yellowflex is a semi-flexible board. Completely free of polyimide, it has no baking requirements, has low moisture absorption, full FR4 compataibility, and passes all IPC TM650 tests. It is suitable for semi-dynamic bending requirements, and small bend radii.

Dr Harald Schenk is Director of Application and Assembly at Freudenberg Mektron, Germany. His subject was some innovative solutions using flexible or Flex-Rigid PCB technology, some applications with special features. The market share of FPC is about 5 percent in Europe, 20 percent in the Far East, and 10 percent in the USA. The demand was in the field of mobile phones. Flex is now used as the hinge, in the keypad, in the LCD, and not unnaturally offers great flexibility, which is a great mechanical advantage. Nippon Mektron/Mektec have developed their own processes for lamination of copper clad materials, and work on a reel-to-reel basis. They have been working on different technologies, such as via formation process, having an FPC moulded into a rigid housing, mounted on a FPC on a heat sink, as a sealant in a fuel pump, as integrated circuit over a moulded connector. The future for such application is in the high value end of the market, in medical applications.

Ending the first day’s sessions Dr Pavlin Sabev of Dyconex AG in Switzerland came along to talk about the plasma ablation process they use at Dyconex, and the UV-laser drilling process they use for microvias. He showed a number of examples of how his company produce very high-density rigid-flex boards. If you have thin substrates, with low specific capacitance, short lines and spaces, minimised sequential, and ground signal power, it takes a long time to design in rather than to produce it. They use Dycostrate™ material for high frequency applications, which allows for 908 bending and which has good thermal aspects.

28 January-Day 2

The Keynote Speaker on the second day was Jacob Azran, President of Orbotech, who spoke about how they see the PCB world. Painting a background to Europe, he said that the UK and Scandinavia were doing better, but that there was low consumer confidence especially in Germany and France, and the strong Euro was weakening European competitiveness with the rest of the world. Prospects for the Euro zone were gloomy. Putting a brave face on it, he said that 3G telecom would bolster European production, the automotive sector was strong, with new electronic systems in cars.

China growth was set to continue for the foreseeable future and in time they will beat us. Strong segments include Flex, HDI and IC. There are no alternative technologies threatening PCBs. The year 2004 was a good year, 2005 softer but still growing. PCB manufacturers are busy, utilisation is up on a global basis, and whilst there is significant expansion in Pacific/China, watch out for overcapacity. Both the Taiwanese and the Japanese continue massive production expansion in China, and the technology employed mirrors that of the mother company; middle and top management usually foreign. Production in the fields of flex and HDI for mobile phones.

Korea has defined their PCB industry as a high priority area, and Samsung has said that they aim to be the largest IC supplier in the world, and they mean it.

In the equipment field Orbotech has seen a strong demand for AOI, Plotters and LDI, which is starting to be seen as a production machine for HDI enabling.

Flex – fine line, and chip on flex are growth areas, and with pressure on packing density 18 and 20 μm line and space will move to production.

PCB volumes are now back to 2,000 levels, interestingly. Of world PCB production, the Far East accounts for 75 percent, Europe 10 percent and Americas 15 percent. By 2007 Europe will be down to 9 percent, Americas down to 14 percent, China up to 24 percent. Microvia technology 50 percent by application to cell phones. Total market $5,675 million.

Stephen Street, Senior Project Engineer from UL UK, covered the requirements and options for fast UL qualification of lead free materials.

He explained that essentially UL is a safety standards organisation. They are working for a safer world. Is their mission statement. China copied us and rolled it out quicker – RoHS. Stephen reminded us that lead absorption adversely affects human health. The WEEE directive reduces the large amounts of electronic waste, in which the major source of pollutants are the heavy metals – cadmium, hexavalent chromium, mercury, and lead. Use of the WEEE directive symbol becomes effective from 31 December 2006 and RoHS effective from 1 July 2006.

UL has been working with ANSI in the US on new standards for FR4 laminates with low levels of halogen. He mentioned that lead free solders are more reliable in certain situations, unlike the older lead free alloys that were quite unreliable. EIA web site is a useful tool or source of information on the subject.

Stephen went through the traditional list of problems in the transition to lead free, the use of various solders for various reflow processes, that higher temperatures are required, which can lead to delamination and warping, thermal shock induced cracks, wetting and solder joint formation and overheating of components and assemblies.

Labelling is now required for lead free – on board finishes, components and assembly solders. Identification is critical for reliable rework.

Tin whiskers, caused by compressive stress build-up during plating, are an issue. Indications for a cure point to a nickel undercoat barrier, annealing or reflow of tin plating, and an additive to create tin alloy such as bismuth. An accelerated test for tin whiskers is still needed, by the US and the UK, and Japan working on this.

The switch to lead free may not impact a UL certification programme, but submit requests as early as possible. Evaluation time to complete testing of 56 day conditioning takes 12 weeks, 10 days conditioning takes 4 weeks. Finally, a word on the RSCS – restricted substances compliance solutions – this is a UL idea for working with suppliers and OEMs to make life easier for manufacturers.

Giacomo Angeloni from Somacis in Italy wanted us to know about a new approval for electronics in aerospace. It is called NAPCAP. It is a single global system, where everyone who supplies the aerospace industry is involved. It is a lengthy process to follow. After an introduction to the construction and formation of NADCDP, Giacomo came to the existence of the ETG, the Electronics Task Group, who are responsible for the PCB aspects – both rigid and flex. These are based on IPC standards, and an audit criteria is followed. The people of ETG are Airbus, Bell Helicopter, General Services Administration, Honeywell, NASA, Northrop Grumman, Rockwell Collins, Rolls Royce, Somacis, Tyco and UTC, and they have set up an audit that is stringent. They recognise AS/ EN/JISQ9100, and ISO 17025. Airbus has picked up NADCAP and is running with it under their Airbus Target system. Useful to know if this is your field.

Bob Neves is the cheerful face of Microlab in the USA and China, and he is concerned about the reliability testing of PCBs to meet the latest developments and standards.

It is an unglamorous business, said Bob, but it has to be done. Talked about reliability testing for PTH and solder joint reliability testing, using his HATSe methodology, which does highly accelerated thermal shock and thermal stress testing. This is used to check soldering process survival. The solder float test is not representative of techniques used in commercial production, his high-speed test systems can change air temperature from – 90 to +160°C in 30 s! He generates samples from a PCB coupon generator, where the coupon emulates a functional PCB design.

Dielektra Technolgie GmbH have Klaus-Dieter Hellmig as their R&D Manager. For anyone who has been hibernating, Dielektra Technologie came into being after an MBO from their former owners last year, and welcome back they are, too, considering they were founded as long ago as 1894. They are now producing 35,000 m² of laminate per week on a continuous reel-to-reel process, with both copper foil and pre-preg laminated together at a speed of 3-4 m/min. There is no handling, just continuous flow. Product range now includes standard FR4 35193-40 with a Tg of 140°C, 35193-50 with a Tg of 150°C and 15193-80 with a Tg of 180°C, MOT of 140°C. They also produce Smartlam for flex, Coblam and Cardlam for the chip industry, and Thermount for laser application. Halogen-free material will be available from the end of March this year. Development products include 40 mm Thermount, other glass types for lasers, Teflon/FR4 hybrid for high frequency application and new polymers for FR4.

Kevin Smith is the LDI Business Manager at Orbotech. LDI is maturing nicely, and they now have 100 systems installed worldwide. During 2003-2004 there was significant growth across the world, Drivers? Not the OEMs. It is the demand for finer lines, reduction in production time, better yields, reduction in labour element. Thirty five systems in the Far East, 30 in Europe, 18 in the USA and 16 in Japan. Thirty one percent of customers have two systems, and multisystem orders from the Far East are now common.

Kevin described two case studies, one where demands for less deviation in impedance measurement was met, with zero repetitive defects due the cleaner environment for LDI; the second where LDI enabled the most improved microvia registration, and a reduction in annular ring misplacement due to an absence of film, with no “off-contact” issues. Image quality is better, with the Paragon 800 25 μ features can be exposed quite readily.

LDI is fast, and Europe continues to see how the benefits can be used to advantage.

LPKF Laser & Electronics AG were represented by the familiar figure of Bernd Lange, their product manager. The motivation for laser imaging was miniaturisation, ultra-fine line circuitry, and the excellent light and energy source. Companies are now using LPKF lasers for cutting rigid and rigid-flex PCBs, with burn-free cutting on faster machines with reduced residue. The criteria for laser-aided imaging was resolution, smoothness of lines, online scaling, and such is their versatility that lasers could be used for selective ablation, selective exposure, and selective activation.

Bernd went on to describe a new approach – direct copper ablation, where conductive tracks are isolated, the “dead” (unwanted) copper is then cut into strips and ablated and blown away. One sq. in./min, and works on most PCB substrates. Laser repair of shorts is another possibility, the LPKF “Laserscalpel” does what it sounds like it should. Safe, clean trimming, and can be used without laser knowledge. Laser ablation of electro-deposited resist means that with very thin resist (1.5- 2.0 μm) laser structuring on top of copper can yield 20 μm lines and spaces. With lasers you can structure very thin metal layers on top of polymers, which is perfect for RFID sensors, and laser activation on prepared polymers allows for the creation of 3D circuitry inside moulded parts.

Wolfgang Albert is the VP Technology at Isola GmbH. He talked about lead free soldering as a challenge for base materials.

With the demands of 1 July 2006 getting ever closer, work has been done at Isola looking at the melting points of different solder alloys. If this melting point is 30°C higher than the melting point of a laminate then you begin to see the problem. So how do we cope?

Adding fillers to the resin can increase the thermal resistance, due to reduced humidity pick-up and a lower z-axis of expansion, which protects the material against thermo-mechanical stress. Also the design of the PCB also has great influence on the thermal resistance during lead free soldering at elevated temperatures. Vapour pressure can increase by up to 2 times higher, so an appropriate drying process is strongly recommended.

The thermal behaviour of a base material is not defined by one characteristic but by Resin type. Use of a crosslinking agent, and the degree of cross-linking, as well as the decomposition temperature of the resin system are all factors in the situation, additionally the PCB manufacturing process itself influences soldering results, and the design of PCB/ MLBs may not be underestimated. Happily there are now several resins systems available, and much higher stress tolerance is possible.

Dr Sylvia Ehrler is the sort of person all good PCB companies should have. What she does not know about laminates is probably not worth knowing, and here she was holding forth on the compatibility of epoxy- based PCBs to lead free assembly.

In about 12 months time a remarkable number of circuit boards will be manufactured with lead free solders, which will bring products to peak temperatures of 260°C over 5-6 reflow cycles. Board reliability after assembly should be better or identical compared to eutectic soldered boards. Extensive work at her company has shown that dicy cured High Tg FR4 does not withstand the thermal stress of lead free assembly conditions. Only phenolic cured epoxy material seems to have the potential to solve the problem.

Her work at Multilayer Technology GmbH was presented in great technical depth, and you are bound to consider the fact that other PCB manufacturing companies in Europe might have benefited significantly for attending, had they done so. The knowledge she imparted to the delegates was worth an annual EIPC membership fee alone in saved effort. Presumably those who were not in Barcelona already have all the answers. For the sake of European PCB manufacture one can only hope so.

Katsumasa Suyama is the Chief Representative in Europe for ESPEC Corporation, and his subject was promoting the commercial adoption of lead free solder and evaluating its reliability.

Based in Osaka, they have been mass- producing PCBs with lead free solder since 2002. They required an analysis for their surface mounting process, facilities and design, and needed to know how to evaluate the reliability of PCBs for problems including thermal stress. The report details are used to promote commercially lead free PCBs and the results of reliability tests in mass-produced items. He explained how his company had approached the subject, how they learnt the importance of the disciplines required, such as keeping lead and lead free operations entirely separate. They adopted a Sn 23.5 Ag 0.75 Cu solder, which has been proven not to fail even after 3,000 thermal cycles, which equates to some 18.5 years of operational life.

Given the depth of experience that is another recommendation not lightly to be ignored.

Sabine Schroder from Ormecon, Ammersbek, in Germany knows all about immersion tin. There is now some new technology available which can help with tin whiskers and meet OEM specifications, she said, and there are several successful ways to suppress tin whiskers; apparently it has much to do with the impact on grain size of the tin; a large grain size is thermodynamically more stable than tin with a small grain size and is less susceptible to recrystallisation. That is not enough on its own, but used a basis for development, Ormecon now says that efficient whisker reduction can be achieved with a process using a new pre-dip coating; based on organic metal and silver, it applies a metallic alloy nanolayer (10-20 nm) containing Ag and Cu on the copper surface prior to depositing the tin.

Ormecon™ CSN FF & FF-W (melting point of 228°C) have very good solderability, and shelf life is extended because there is a lower diffusion speed. Tests with customers in China and Japan have shown very good solderability, even after multiple temperature cycles, also it is good for lead free process conditions.

Enhancing the tarnish performance of immersion silver finishes was the title of a paper presented by Joanne Spencer of MacDermid who had flown over from Florida to address the conference. Joanne was here to talk about silver as a predominant choice for lead free finishes.

In the period 1995-2004 she said that silver was becoming a challenger to HASL as a lead free finish. OSP has been around for 20 years in various forms, it was always a fast low-cost process, but had a limited shelf-life and some of the older OSPs were flux sensitive. Also it was not inspectable.

ENIG was expensive, attacked solder masks, needed a complex process, was not reworkable, had Ni/Sn brittle solderjoints and there was some interfacial fracture. However, it did have a long shelf life and was widely available.

Immersion tin was low cost, had minimal tarnish, was reworkable, had flat/fine pitch, and cu/Sn solderjoint. However, the shelf life is much reduced and it is considered a carcinogen.

Immersion silver, she concluded, was the “real thing”. It has low cost, excellent wetting, simple processing, flat/fine pitch and cu/Sn solderjoints, has good contact functionality and eliminates selective processing. Some previous concerns about migration have been solved and now there is a tarnish inhibitor that works just fine. Touchpad functionality is good. Joanne described the work that had gone into providing a proven tarnish free immersion silver finish that would be perfect for those moving into the lead free soldering world, both now and next year. Rather aptly it is called Standard Sterling™ Silver.

Long way from Florida, but we are glad she came.

EIPC have an inherent knack of running great conferences, and this one was not an exception. Some excellent papers, and a whole lot of useful information. Anyone hoping for a few days in Barcelona to escape the chill of winter was in for a nasty shock; winter had followed them over the Pyrenees and was blowing around the city streets with a cheek-chapping intensity. However, inside the conference all was warmth, light and illumination, and the conference dinner, held in The Crazy Crab restaurant overlooking the harbour, was window-steamingly enjoyable.

Hopefully Stockholm in June will be a little warmer. It will certainly be much lighter.

John LingAssociate Editor