Just like old times—meeting with John Ling, with whom I had previously travelled to industry events for over two decades, and who still carries the role of EIPC marketing manager, to fly together from Birmingham UK to Dusseldorf in Germany for the EIPC 50th Anniversary Summer Conference.

To borrow from Ling’s words of introduction in EIPC’s invitation to attend: “Half a century has passed since EIPC was founded in the days when the PCB was more than just a commodity. PCBs were technological works of art, and fellow artists came together to compare notes and to see which galleries were having good exhibitions and commissions.” And about the bonus-programme factory visit, the art gallery analogy continued as he described Unimicron's new multilayer facility in Geldern as “The Tate Modern of the European PCB industry.”

Representing 17 countries, 135 delegates were made welcome by EIPC President Alun Morgan, recently re-elected for a third term of office. He quoted Bernard Bismuth, long-time stalwart of the French industry, 43 years general manager of CCI Eurolam and currently Affiliate Professor at HEC in Paris, who described the PCB as: “The last product to be defined and the first to be needed, and it keeps changing!”

Morgan wound back the clock to 1968, the year in which EIPC was founded by Dr Mario Fassini, when Apollo 8 became the first manned spacecraft to orbit the Moon and return safely to Earth, Martin Luther King and Bobby Kennedy were assassinated, and a 3-kilometre geodesic dome covering Midtown Manhattan was proposed by Buckminster Fuller.

The form of Fuller’s geodesic dome was significant in the naming of spherical allotropes of carbon consisting of 60 atoms and 90 covalent bonds arranged in 12 hexagons and 20 pentagons— “Fullerene,” alternatively “Buckyballs.” Morgan challenged the audience to build a ball-and-stick molecular model of Fullerene and was impressed when Emma Hudson promptly presented him with a perfect replica!

The thread of his discussion progressed through carbon nano-tubes to the wonder-material graphene—even demonstrating how he made some of his own using a stick of graphite and a roll of adhesive tape—which he believed would be a key enabler in next-generation electronics.

Morgan concluded his introduction with greetings from founder Dr. Fassini, who had managed the institute through its first 25 years, and introduced Walt Custer, whose “business outlook on the global electronics industry with an emphasis on Europe” is always eagerly awaited and has deservedly become recognised as the definitive guide to what to expect in forthcoming months.

Custer began with words of warning: “I’m a little more subdued than I was last year. Leading indicators are starting to cool, and growth is slowing. Be aware that things could slow down.” His summary of business conditions in the world electronics industry indicated that after strong growth in 2017, expansion had now slowed, although the calculations could be significantly distorted by differences in exchange rates—apparent growth calculated in U.S. dollars far exceeded the figure based on Euros. Passive component shortages remained a big problem and memory demand continued to drive semiconductor sales. And, inevitably, these demands and shortages supported price increases. The principal growth drivers were automotive, industrial and Internet of Things, and 5G and other disruptive technologies were emerging. But geopolitical concerns remained very significant, and if trade disputes escalated there was a real risk of a global slowdown.

Custer foresaw major disruption in the automotive industry globally over the coming decade, with the trend towards autonomous vehicles initiating the restructuring of entire industry segments. And although many new jobs would be created, particularly in semiconductors and electronic systems, hundreds of thousands of existing ones could be lost.

Looking at the prospects for the European PCB industry, which represented less than 4% of world production, the total for 2017 had been estimated between 1.86 and 1.88 billion euro, split Germany 43%, Austria/Switzerland 18%, Italy 10%, France 9%, UK 8% and Scandinavia 2%. Top five European manufacturers were AT&S in Austria, Würth, Schweizer and KSG in Germany, and Elvia in France. Although continued growth was expected in 2018, it would not be as strong as in 2017, and uncertainty about the future of multinational treaties and trade agreements was having an adverse effect on business confidence.

Emilie Jolivet, Semiconductor and Software division director at Yole Développement, the "More than Moore" market research and strategy consulting company, was the second keynote presenter, with a discussion of developments in advanced substrates and embedded die technology that could lead to a renewal of the PCB industry. She commented that form factor was currently the main driver for PCBs and substrates. There was a technology gap between substrate manufacture, with lines and spaces at 5 microns trending to 2 microns, and PCB manufacture, with lines and spaces at 30 microns. The substrate-like-PCB (SLP) bridged this technology gap, although it needed investment in new manufacturing technologies to make it available and affordable.

With the demand for higher battery capacity in smartphones, the space available to accommodate the electronics continued to decrease, so circuit boards needed to be smaller and with more functionality. HDI was being pushed to its limits of interconnection density, and Apple had set a new trend by introducing SLP into its latest iPhones. SLP could effectively offer double the efficiency of HDI. For example, whereas a current smartphone might have a 10-layer HDI board with 40-micron line and space, the next generation could have 20-layer stacked SLP with 25-micron line and space and occupy 40% less space. PCB and substrate manufacturers had started producing SLP and investing in mSAP and a few already had the capability. It was forecast that by 2023, 17% of all smartphones would use SLP.

Jolivet spoke at length about embedded die packaging trends and cost considerations, and about embedded interconnections in substrate, with reference to Intel’s embedded multi-die interconnect bridge—a package without through-silicon-vias as an alternative to the costly 2.5D silicon interposer, with an embedded interposer in a flip-chip BGA substrate. Forecasts for embedded die revenues showed substantial growth not only in smartphones but in automotive power converter applications as well, for reasons of form factor, higher component integration with shorter interconnections, thermal management and protection from harsh environments.

Continuous improvements in manufacturing capability and yield enabled the embedding of higher value components. Embedded die packaging already offered solutions for low to middle power applications and the gap in integrated packaging for middle and high-power applications could be filled by embedding the die in the PCB.

Substrate manufacturers were trying to find their way into the packaging business, and many commercial and development partnerships had already been established in the supply chain. And China was entering a technology area which had been seen traditionally as European and Japanese.

Just like old times—meeting with John Ling, with whom I had previously travelled to industry events for over two decades, and who still carries the role of EIPC marketing manager, to fly together from Birmingham UK to Dusseldorf in Germany for the EIPC 50th Anniversary Summer Conference.

To borrow from Ling’s words of introduction in EIPC’s invitation to attend: “Half a century has passed since EIPC was founded in the days when the PCB was more than just a commodity. PCBs were technological works of art, and fellow artists came together to compare notes and to see which galleries were having good exhibitions and commissions.” And about the bonus-programme factory visit, the art gallery analogy continued as he described Unimicron's new multilayer facility in Geldern as “The Tate Modern of the European PCB industry.”

Representing 17 countries, 135 delegates were made welcome by EIPC President Alun Morgan, recently re-elected for a third term of office. He quoted Bernard Bismuth, long-time stalwart of the French industry, 43 years general manager of CCI Eurolam and currently Affiliate Professor at HEC in Paris, who described the PCB as: “The last product to be defined and the first to be needed, and it keeps changing!”

Morgan wound back the clock to 1968, the year in which EIPC was founded by Dr Mario Fassini, when Apollo 8 became the first manned spacecraft to orbit the Moon and return safely to Earth, Martin Luther King and Bobby Kennedy were assassinated, and a 3-kilometre geodesic dome covering Midtown Manhattan was proposed by Buckminster Fuller.

The form of Fuller’s geodesic dome was significant in the naming of spherical allotropes of carbon consisting of 60 atoms and 90 covalent bonds arranged in 12 hexagons and 20 pentagons— “Fullerene,” alternatively “Buckyballs.” Morgan challenged the audience to build a ball-and-stick molecular model of Fullerene and was impressed when Emma Hudson promptly presented him with a perfect replica!

The thread of his discussion progressed through carbon nano-tubes to the wonder-material graphene—even demonstrating how he made some of his own using a stick of graphite and a roll of adhesive tape—which he believed would be a key enabler in next-generation electronics.

Morgan concluded his introduction with greetings from founder Dr. Fassini, who had managed the institute through its first 25 years, and introduced Walt Custer, whose “business outlook on the global electronics industry with an emphasis on Europe” is always eagerly awaited and has deservedly become recognised as the definitive guide to what to expect in forthcoming months.

Custer began with words of warning: “I’m a little more subdued than I was last year. Leading indicators are starting to cool, and growth is slowing. Be aware that things could slow down.” His summary of business conditions in the world electronics industry indicated that after strong growth in 2017, expansion had now slowed, although the calculations could be significantly distorted by differences in exchange rates—apparent growth calculated in U.S. dollars far exceeded the figure based on Euros. Passive component shortages remained a big problem and memory demand continued to drive semiconductor sales. And, inevitably, these demands and shortages supported price increases. The principal growth drivers were automotive, industrial and Internet of Things, and 5G and other disruptive technologies were emerging. But geopolitical concerns remained very significant, and if trade disputes escalated there was a real risk of a global slowdown.

Custer foresaw major disruption in the automotive industry globally over the coming decade, with the trend towards autonomous vehicles initiating the restructuring of entire industry segments. And although many new jobs would be created, particularly in semiconductors and electronic systems, hundreds of thousands of existing ones could be lost.

Looking at the prospects for the European PCB industry, which represented less than 4% of world production, the total for 2017 had been estimated between 1.86 and 1.88 billion euro, split Germany 43%, Austria/Switzerland 18%, Italy 10%, France 9%, UK 8% and Scandinavia 2%. Top five European manufacturers were AT&S in Austria, Würth, Schweizer and KSG in Germany, and Elvia in France. Although continued growth was expected in 2018, it would not be as strong as in 2017, and uncertainty about the future of multinational treaties and trade agreements was having an adverse effect on business confidence.

Emilie Jolivet, Semiconductor and Software division director at Yole Développement, the "More than Moore" market research and strategy consulting company, was the second keynote presenter, with a discussion of developments in advanced substrates and embedded die technology that could lead to a renewal of the PCB industry. She commented that form factor was currently the main driver for PCBs and substrates. There was a technology gap between substrate manufacture, with lines and spaces at 5 microns trending to 2 microns, and PCB manufacture, with lines and spaces at 30 microns. The substrate-like-PCB (SLP) bridged this technology gap, although it needed investment in new manufacturing technologies to make it available and affordable.

With the demand for higher battery capacity in smartphones, the space available to accommodate the electronics continued to decrease, so circuit boards needed to be smaller and with more functionality. HDI was being pushed to its limits of interconnection density, and Apple had set a new trend by introducing SLP into its latest iPhones. SLP could effectively offer double the efficiency of HDI. For example, whereas a current smartphone might have a 10-layer HDI board with 40-micron line and space, the next generation could have 20-layer stacked SLP with 25-micron line and space and occupy 40% less space. PCB and substrate manufacturers had started producing SLP and investing in mSAP and a few already had the capability. It was forecast that by 2023, 17% of all smartphones would use SLP.

Jolivet spoke at length about embedded die packaging trends and cost considerations, and about embedded interconnections in substrate, with reference to Intel’s embedded multi-die interconnect bridge—a package without through-silicon-vias as an alternative to the costly 2.5D silicon interposer, with an embedded interposer in a flip-chip BGA substrate. Forecasts for embedded die revenues showed substantial growth not only in smartphones but in automotive power converter applications as well, for reasons of form factor, higher component integration with shorter interconnections, thermal management and protection from harsh environments.

Continuous improvements in manufacturing capability and yield enabled the embedding of higher value components. Embedded die packaging already offered solutions for low to middle power applications and the gap in integrated packaging for middle and high-power applications could be filled by embedding the die in the PCB.

Substrate manufacturers were trying to find their way into the packaging business, and many commercial and development partnerships had already been established in the supply chain. And China was entering a technology area which had been seen traditionally as European and Japanese.

The final keynote presentation came from Roger Massey, technology strategy and strategic marketing manager at Atotech, with a perspective on the changing shape of the HDI market.

He explained that HDI PCBs had evolved through three generations: originally subtractive technology with lines and spaces down to 60 microns, through any-layer technology with lines and spaces down to 40 microns, to modified semi-additive technology to achieve lines and spaces of less than 30 microns. Commenting that technology roadmaps, of which there were many, had historically served as useful educated guesses to indicate future interconnection density requirements, their predictions had largely been blown away by recent market developments in mobile devices. Handsets were becoming thinner and although screen sizes were increasing, there was less space available for the PCBs because larger batteries had to be accommodated. This was driving a technology shift towards smaller form factors and designs and pushing the HDI market for increased interconnection density by miniaturization of holes, pads and conductors to improve connection to the next system level, typically either an IC substrate or some form of direct chip attach, as well as the need to maximise electrical performance, reduce latency and increase signal speeds.

Sub-30-micron lines and spaces could not be achieved with panel plating techniques and needed modified semi-additive processing (mSAP) or advanced modified semi-additive processing (aMSAP). Copper foils as thin as 2 microns were required, with improved surface treatments to enable more efficient laser drilling of ultra-small microvias, and new lasers with picosecond and femtosecond pulses to minimise heat damage whilst achieving maximum via density.

Chemical process suppliers were developing innovative solutions to meet the current and future market needs. These included surface preparation and multilayer bonding treatments, small via desmear and high throw electroless copper for small microvias, copper plating electrolytes capable of via filling and pattern plating simultaneously, photoresist strippers and etchants capable of working with sub-30-micron lines and spaces, and final finishes to ensure solder joint reliability and electrical performance with smaller pad sizes.

Massey’s closing comment was: “The next five years are going to be very challenging—we as an industry can deal with that!”

EIPC vice-president Emma Hudson moderated Session 2, entitled European PCB History and Future, and invited Paul Waldner, managing director at Multiline International Europa and a former EIPC chairman, to look back over the past 50 years with a brief history of printed circuit board manufacturing in Europe.

Apologising that he had only been in the industry for 44 years, having started as a designer in the days of taped artwork, Waldner looked back even further, to the original invention of the printed circuit by the Austrian engineer Paul Eisler while working in England around 1936, and tracked the development of the technology and the European industry since that time, with a long list of notable names and events along the way. His presentation triggered many memories from elder statesmen of the industry who sat in the audience, especially when his old photographs challenged delegates to identify names, faces and occasions.

The decision to form EIPC had been made at the 1968 Electronica show, with the objective of representing the European industry’s needs in terms of culture, work ethics, technology and social-work interfaces. EIPC’s role grew to provide education and training to the industry, networking at all levels. and collaboration with standardisation bodies in the development of IEC standards. The first Printed Circuit World Conference was held in London in 1978, a joint effort between EIPC, ICT, IPC and JPCA.

By 1980, Europe’s printed circuit production had reached about $1.3 billion. By 2000, sales had grown to a peak of about $6.5 billion, and since then there had been a steady decline until about 2015 when sales levelled off at approximately $2.8 billion per year. Presently, HDI, flex and flex-rigid PCBs comprised 30% of European PCB production, and there were signs that output might begin increasing along with general world demand growth for PCBs in areas of low production quantities like medical, military, avionics, industrial and in high value circuitry utilising high speed materials and flex-rigid constructions.

Whereas Paul Waldner had looked back, industry analyst and strategist Hans Friedrichkeit looked ahead at technology drivers for the printed circuit boards of tomorrow. “Do you remember 2008 or the millennium? No problem! But what will our world look like in 2028?”

Friedrichkeit used many video illustrations to exemplify what was to come: “We live in a time of disruptive innovation in which existing technologies are quickly supplanted. Twenty-five years ago, the mobile phone made communication possible anytime, anywhere. Eleven years ago, the iPhone opened the smartphone era. The convergence of language, image and data with countless apps became reality. Nine years ago, Tesla launched E-Mobility with its Roadster. Currently the first fuel cell vehicles and even bicycles are on the road.”

About advanced driver assistance systems, he continued: “We will quickly get used to autonomous parking, traffic jam assistants and autonomous driving on motorways. The first driverless robotic taxis are in trial operation and in about seven years we will be able to drive autonomously to the front door.” He cited Mercedes’ Smart concept car, the Smart Vision EQ Fortwo, demonstrated at CES 2018, with no steering wheel, no pedals and operated by smartphone, as offering a new vision of urban mobility and efficient local public transport. Further in the future was an intelligent vehicle chassis with a detachable passenger pod that could be lifted and transported by a drone and placed down on another chassis in a distant urban location. “The future will be even more exciting and is coming faster than expected!”

The next presentation, from Pavel Gentschev, chief technical officer at Lackwerke Peters, discussed possibilities and experiences in achieving thermal management improvements with specialised coatings on printed circuit boards.

The U.S. Air Force Avionics Integrity Program had identified temperature as the principal cause of failure in its electronic systems, accounting for 55% of all failures investigated, and attributed to density of components, high power components and applications in areas with high ambient temperatures.

So how to manage the heat? Gentschev reviewed the theoretical principles of heat conduction and heat dissipation, thermal impedance and the significance of interfaces. He discussed how thermal interface materials could improve heat coupling and heat transition and how low-shear-modulus formulations could also help with thermal-mechanical decoupling at interfaces between materials with different thermal expansion characteristics.

He listed the limitations of thermal greases, thermal foils and gap pad materials, showed examples of printed thermal interface materials that could be screen printed by the PCB fabricator in layer thicknesses of 30 to 150 microns, and summarised the characteristics and selection criteria for thermal interface pastes. And whereas traditionally heat-sinks were bonded-on as separate components, it was practicable to use heat-sink pastes to print them directly onto the surface of the PCB, and if necessary to use them in combination with printed thermal interface pastes. He showed several application examples and the results of comparative thermographic measurements.

As I-Connect007 technical editor and a technical consultant to EIPC, I was delighted to be invited to moderate the third conference session, on the theme of safety, process reliability and traceability in automotive PCBs. 

My first speaker was Frank Tinnefeld, joint managing director of ASS-SAA Automation, on the subject of fully integrated PCB production automation. His presentation referred specifically to the latest status of the new Unimicron factory in Geldern, for which his company had provided the automation and handling systems.

After the fire in December 2016 which destroyed their innerlayer plant, Unimicron moved quickly to specify its replacement in cooperation with ASS Luipold and SAA, who were later to merge their product portfolios as ASS-SAA Automation. The target definition was clear: the newest art of technology, to be prepared for future market requirements, with lead-time reduction by in-line production automation wherever it was useful, automation of all production processes, 100% order tracking and the elimination of manual order input and accompanying paperwork wherever possible.

The production concept was to cluster innerlayer manufacture: in-line from loading the pre-clean to unloading the develop-etch-strip line, AOI, then in-line from loading the innerlayer punch to unloading the bonding-treatment line, then multilayer lay-up and lamination followed by outer-layer X-ray and multilayer edge trimming, before proceeding to outer-layer production.

The equipment concept was realised by the integration of smart work-in-process storage solutions, first-in-first-out buffers and automatic guided vehicles carrying the work between develop-etch-strip and AOI, between AOI and innerlayer punching and bonding treatment, and between bonding treatment and multilayer lay-up. This enabled automated process load-unload without interruption of production in the case of a change of material, with double pallet automation, double cassette automation and double pallet interleave handling.

Every single panel was marked with a unique data matrix code (DMC) to enable 100% panel tracking through the entire process and every work-in-progress cassette was tracked via its barcode and its contents were always identified. And the intelligent manufacturing execution system integrated smoothly with the customers’ ERP and quality systems.

Tinnefeld’s presentation was an exemplary demonstration of the PCB 4.0 smart factory concept and provided a meaningful introduction and background to the Unimicron visit which followed at the end of the conference day.

A further example of automation and traceability in Smart manufacturing was provided by Jochen Zeller, vice-president and co-founder of AWP Group, suppliers of material handling and automation systems and horizontal wet processing equipment, who took as his model the Industry 4.0 factory integration project at Whelen Engineering’s GreenSource PCB fabrication plant in Charlestown, New Hampshire, USA.

The project mission had been to create a fully automated, integrated and data-driven PCB factory, realising a true single-piece flow. Zeller demonstrated how the automation and integration concept had been achieved using the example of the innerlayer cell. He described the features of key equipment, with specific reference to a flexible robot system capable of the gentle handling of ultra-thin material with contactless centering, which utilised a 6-tray transport cart with individual access to each tray based on data input from the MES system. Trays were loaded automatically into the machine in random order and each tray was equipped with an RFID chip, as was the cart itself. Five of these robot units were employed in the innerlayer cell.

The second piece of key equipment he described was a flexible buffer which controlled how many panels were in the entire system to ensure all the panels could be stored in a fault situation. The buffer system used pick-and-place, rather than belts, for particle-free operation and was fully flexible to compensate for different line speeds in an interconnected system. Three of these buffers were used in the innerlayer cell.

Each panel had a unique DMC code, and DMC readers were positioned at every stage of the process. If, for example, a program change was required on-the-fly at the etching machine to compensate for different copper thicknesses, all the spray bars were individually controlled, and the change would be initiated based on the data input from the DMC code on that panel. Additionally, there were RFID read-write heads and connection modules at several stages in the innerlayer cell to track carts and trays. The project mission had been achieved and the fully-automated, integrated and data driven PCB factory, with single-panel flow, had been realised.

Recently returned to Europe after a few years in the USA and China, we welcomed back former EIPC vice president Giacomo Angeloni, product realisation director with Mektec Europe. Being a football fan, he could not resist a dig at the England team’s chances in the World Cup competition in Russia, with a cartoon of their bus parked on the short-stay at Heathrow!

To more serious matters, he gave an enlightening presentation on safety in connecting technology for battery cells in EV cars. He explained that Mektec Europe is a major supplier of flexible circuits, assemblies and modules to the automotive industry, and that flexible circuits were at the crossroads of innovation in the automotive market.

Fires had been associated with lithium batteries in several high-profile incidents, notably with Boeing, Samsung and Tesla, but in the automotive examples only a very small proportion of highway fire accidents could be attributable to lithium batteries and then the problems had typically been related to overcharging or mechanical abuse. But there was still plenty of scope for improvement in some of the techniques used to interconnect the cells within the battery, to simplify the connection, avoid the possibility of short circuits, and accommodate dimensional changes during charging and discharging. Flexible circuit techniques offered reliable and cost-effective solutions. Connection could be made by riveting or ultrasonic bonding, and fuses and over-temperature sensors could be incorporated. He showed several examples of non-safe and safe connections and passed round several hand samples. Typical base materials were 2-mil polyethylene naphthenate, and 2-mil or 1-mil polyimide.

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