EIPC Winter Conference 2023: Day 1 Review
The EIPC Winter Conference returned to the Metropolis of Lyon in eastern France this month. In 2018, the venue was Villeurbanne in the Auvergne-Rhône-Alpes region. Five years later the setting was the Groupama Stadium in Décines-Charpieu, and leaders of the European printed circuit community gathered in expectation of a spectacular programme of 16 presentations, a visit to a nuclear power station, and an invaluable networking opportunity. They weren’t disappointed.
EIPC President Alun Morgan welcomed a packed house, acknowledged the support of the sponsoring organisations, and remarked that the Institute had gained 13 new member companies during 2022.
Energy security and supply continue to be issues of great concern to EIPC and its members; Morgan’s opening presentation focused on global energy consumption, alternative energy sources and renewable technologies. He commented upon the significance of decarbonisation in energy evolution, but remarked that existing fossil fuels must be displaced much more rapidly in the energy mix to achieve meaningful progress in meeting future demands.
In Europe, France has established its own energy security by actively developing nuclear technology and is one of the most nuclear-powered countries in the world, typically producing over 75% of its electricity from its 56 reactors; it provides about 15% of Europe's total power through exports. Ongoing, there is a trend toward small and simpler units for generating electricity from nuclear power, and the International Atomic Energy Agency continues to facilitate the development and deployment of small modular reactors.
Morgan concluded with the observation that the alternative to nuclear power is not forests and green meadows but less efficient and far more polluting conventional power plants. The risks of nuclear power generation must be balanced against the well-understood and certain harms from the use of fossil fuels.
It is a long-standing tradition that the conference programme begins with Custer Consulting Group’s business outlook on the global electronics industry (with emphasis on Europe). The Keynote Session was moderated by EIPC Technical Director Tarja Rapala-Virtanen, who invited Alun Morgan to return to deliver the presentation on Jon Custer’s behalf.
Although 2022 started strongly, there were serious global economic consequences: the Russian invasion of Ukraine which, together with inflation and the Omicron variant that closed Shanghai, caused worsening supply chain disruptions. Food prices soared, the economy rocked housing markets worldwide, and work on many large projects in China stopped. Inflation in many countries hit levels not seen since the 1980s and the IMF warned that the world could soon be “teetering on the edge of a global recession.”
Meanwhile, there were major gains in electric vehicles and advancements in automation and robotics. The number of PCB manufacturers in Europe fell to 173 in 2021, with revenues of 1.648 million euro. Michael Gasch had estimated that 2022 revenues would be in the range 1760–1810 million euros.
What was the global outlook for 2023? There was a great deal of uncertainty regarding global economic policy:Average oil prices are expected to remain above $90 per barrel and will contribute to relatively high global inflation. The U.S. dollar is expected to remain close to its current level, although this will be affected by geopolitical tensions and Federal Reserve policies relative to those of other central banks. The U.S. will likely suffer a textbook-style recession, and China might pay a high price for its procrastination in implementing a “living with COVID” approach.
Analysts expect Europe’s economic momentum to diminish in 2023 with tightening monetary policy, and the United Kingdom to record the weakest performance of any European economy. Inflation is expected to be highest in central and southern Europe. It will be lower by comparison in northern and western Europe, but still high by historical standards.
The second presentation in the Keynote Session, “IC Substrate: Key Element of the Packaging Industry,” came from Emilie Jolivet, director of the Semiconductor, Memory and Computing Division at Yole Développement in France. She has surveyed technology and market trends, and shared an abundance of forecasts and statistics.
She described the increasing requirement for laminate IC substrates, commenting that since 2018, there has been an overwhelming demand for flip-chip BGA and flip-chip CSP substrates from 5G and high-performance computing. Significant technology turning points have been the change in IC substrate material from ceramic to organic and in interconnection from wire bonding to flip-chip. During the pandemic period, the high demand for a whole range of electronic equipment, from personal devices to data centres using more advanced packages, has led to an unprecedented shortage of advanced substrates.
Her advanced packaging technology roadmap indicated bump I/O pitch to be scaling much faster than ball I/O pitch, in turn driving finer redistribution layer lines and spaces at IC substrate package level, trending toward 2 microns with bump pitches of 40 microns and ball pitches of 300 microns by 2027.
Jolivet estimated that the global advanced substrate market value will grow from $15.8 billion in 2021 to $29.6 billion in 2027, mainly driven by the high demand in mobile and consumer, automotive and mobility, and telecom and infrastructure. It is forecast that advanced packaging revenue in the total semiconductor market will exceed traditional packaging revenue by 2026. The advanced packaging market was worth $37.5 billion in 2021 and is expected to grow to $65 billion in 2027. The flip-chip platform, which includes flip-chip BGA, flip-chip CSP, and flip-chip SiP, will have the highest market share, and the highest growth rates will come from embedded-die, 2.5D/3D, and fan-out packaging.
The period from 2021-22 saw unprecedented investment in capacity, mostly in Asia. Of a total of more than $16 billion worldwide, by far the largest proportion was in China, followed by Taiwan, Malaysia, Japan, Korea, and Vietnam, with comparatively small investments in Austria and the U.S.
She commented that the main substrate technology trend is to increase complexity with larger areas, more layers and finer pitches, and lines and spaces by adopting processes like SAP, mSAP, or aSAP. Embedded die technology will enable multiple die embedding to reach more applications.
The final keynote presentation, “A Charcoal Sketch of the Energy System,” was by Gerrit Jan Schaeffer, general manager of EnergyVille, a collaboration of Belgian research partners in the fields of sustainable energy and intelligent energy systems.
“The world is changing,” he began, as he indicated how world population, world energy consumption and carbon dioxide emissions are expected to progress from 1990 to 2050. The population will increase from 5.3 to 9.7 billion and energy consumption will increase from 8,000 to 21,000 million tons of oil equivalent per year, but carbon dioxide emissions must be be reduced from 22.4 billion tons per year to net-zero in order to minimise the rise in global temperature.
He explained what a global net-zero energy system w look like by considering the four sectors that have accounted for more than 90% of domestic, energy-related CO2 emissions in the EU in 2020: mobility, industry, buildings, and the electric power sector. He analyzed each one in detail and demonstrated how they would interact.
“What about hydrogen?” he asked, referring to proposals to employ hydrogen as a tool for decarbonisation. He showed a chart known as the Hydrogen Ladder, which was created by Michael Liebreich in an attempt to rationalise suggested applications; they ranged from “unavoidable” in green at the top to “uncompetitive” in red at the bottom. He is a firm advocate of decarbonising the planet as quickly and cost-effectively as possible, but is strongly against using clean hydrogen in sectors where there are cheaper and more efficient electric solutions, such as cars and domestic heating.
The estimated global hydrogen need in 2050:
- Unavoidable applications, 350–400 million tons
- Industrial applications, 175 million tons
- Sipping, 95 million tons;
- Aviation, 90 million tons
It is estimated that between 20,000 and 25,000 terawatt hours of green electricity will be required to produce this amount of hydrogen, bearing in mind that current global power production is about 27,000 terawatt hours. Schaeffer’s conclusion was to avoid hydrogen where and if possible, because massive amounts will be needed already for the hard-to-abate sectors.
The theme of the following conference session was “Environment and Sustainability,” and it was moderated by Alun Morgan.
The first contributor was EIPC board member Stig Källman, master developer component engineer PCB with Ericsson in Sweden. Unable to attend in person, he provided a video presentation titled, “Ericsson Supplier Climate Action,” describing how conducting business responsibly is at the foundation of Ericsson’s approach to sustainability and corporate responsibility.
He outlined the company’s Responsible Sourcing Environment Program, a code of conduct for business partners that supports and encourages suppliers to conduct their own businesses in ways that minimise negative environmental impacts for their own operations and in their supply chains. Based on scientific evidence and in alignment with the Business Ambition for 1.5°C, Ericsson’s target is to halve emissions by 2030 and to drive action on the pathway to a net-zero value chain by 2040.
Part of the code of conduct for Ericsson’s procurement process is a section on climate change mitigation that requires all business partners to develop and implement plans and targets to reduce their greenhouse gas footprint, adopt and publicly disclose its targets for halving absolute greenhouse gas emissions by 2030, and offers guidance and support on how to proceed.
Ericsson’s own activities to reduce CO2 include energy efficiency, design for reduced size and weight, use of materials with reduced density or enhanced characteristics, improved manufacturing methods and supplier selection based on low CO2.
Surface Finish Conductivity
Morgan next introduced Dr Kunal Shah, president of LiloTree, who offered recommendations on achieving optimum signal integrity at 5G millimetre-wave frequencies using a novel nickel-free surface finish for PCBs. The process he described was cyanide-free, halogen-free and compliant with RoHS and REACH directives.
Shah reviewed the causes of insertion loss on high-frequency PCBs and indicated a correlation between conductor loss and the selection of surface finish. Electroless nickel immersion gold is a commonly used finish, characterised by long shelf life and low surface roughness, but the low conductivity of nickel has an adverse effect on insertion loss. Moreover, electroless nickel is associated with hyper-corrosion issues and brittle solder-joint failures.
Of the alternative finishes available, immersion silver has limited shelf life and poor corrosion resistance, and direct immersion gold, electroless palladium immersion gold, and electroless palladium autocatalytic gold show concerns in terms of higher insertion loss and brittle solder joints; they are not cost-effective at higher precious metal thicknesses.
Shah introduced a novel nickel-free surface finish: 50 nanometres of cyanide-free gold on copper treated with a nano-engineered barrier layer. This enables robust solder joints with thin and distinct intermetallics. The finish is cost effective because of its significantly lower thickness of gold than the alternative nickel-free finishes mentioned.
The nano-engineered barrier layer on the copper surface prevents diffusion of copper into the gold, leaving the surface corrosion-free even after six reflow cycles, and the finish shows insertion loss equivalent to bare copper. It has been exhaustively tested and confirmed as a high-reliability finish for high-frequency applications.
Dry Phase Patterning
“And now for something completely different,” Morgan said as he introduced Dr. Roland Bejjani from DP Patterning in Sweden, who has a novel process for volume production of simple flexible circuits without chemical etching. Dry Phase Patterning is a mechanical reel-to-reel process and the self-contained unit is designed to be used in-house and integrated with final assembly, as an alternative to relying on sub-contract suppliers. It has particular appeal to manufacturers in the automotive, LED lighting, and RFID sectors, simplifying the production process, reducing lead times and transport logistics. Because there is no chemistry involved, waste management is simplified.
The basic imaging tool, known as a cliché, is made in the form of a metal roller on standard equipment well-known in the printing industry. A web of flexible material—Bejjani’s example was single-sided 18 micron copper on 50 micron polyimide travelling at 10 metres per minute—is passed between the cliché and a milling wheel that mechanically removed the protruding pattern from the copper layer, leaving the required conductor pattern at a resolution of 100 microns, while the dielectric layer remains untouched.
Dry phase patterning technology can also be used for the texturing of metallic films by alteration of micro-topography, as well as for various non-electronic and non-conductive applications.
The session on new process technology and Smart manufacturing was moderated by Emma Hudson from EHTC in the UK. Her first presenter was Philip Johnston, CEO of Trackwise Designs, also in the UK, who added a further dimension to the technology of flexible circuit fabrication with his paper on “Length-agnostic FPC manufacturing.”
What was meant by length-agnostic? Trackwise has established the unique capability to produce multilayer flexible printed circuit boards of any length, the ultimate length being governed only by the availability of suitable material. Their proprietary technique is based on roll-to-roll processing and digital imaging. Developments in software have given them the capability to produce non-repeated and non-separated images.
Trackwise’s key markets are the automotive, aerospace, medical, scientific, and industrial sectors. In automotive applications, flexible PCBs are suited to electric vehicles in battery modules, battery packs, and battery management systems. Examples with copper weights of six ounces are capable of carrying high-voltage power. In aerospace, large-scale flex (LSF) offer a 70–90% weight reduction in data cables and 10–20% weight reduction in power cables. They can be used for fuselage-length or full-wing-width interconnects and are qualified for high temperature operation in harsh environments. At the other end of the scale, long, ultra-flexible and finely etched printed circuits have become key enablers for catheter-based distal electronics, with tracks and gaps as small as 50 microns.
Trackwise has established the capability to carry out roll-to-roll assembly, giving the potential for active interconnect, Smart harnesses, and flexible hybrid electronics.
CAM and AI
Hudson next introduced Claudio Bellistri, European business manager for KLA-Orbotech in Belgium, who discussed CAM-based analytics using machine learning and artificial intelligence in the context of the Smart PCB factory. Building on their background of experience in front-end manufacturing processes and CAM reference technology, KLA’s software gives easy access to visual analytics that enable quality issues to be addressed proactively and rapid corrective action to be taken.
The system is capable of merging cross-departmental data and CAM-based analytics, and can be connected seamlessly to multiple machines and vendors, across numerous sites and hundreds of connected machines.
It offers a one-stop solution for electrical testing and AOI, with the facility to view comparative data to identify potential root causes. Defects are shown on the selected CAM feature to make analysis easier and an interactive defect gallery offer a large reference album of images and videos. The distribution of repeated defects and the number of repetitions are available to view on multiple panels, and data can be shared and exchanged with third-party software.
The final presentation in the session on new process technology and Smart manufacturing was given by automation specialist Frank Tinnefeld of ASS Luippold in Germany. His talk, “Smart Factory Solutions,” described an impressive range of automated tasks in printed circuit manufacture, from simple economic solutions to complex and customised automation.
Tinnefeld’s portfolio includes base material logistic and work-in-process storage solutions using automatic guided vehicles and autonomous mobile robots, wet processes, exposure and AOI processes, inner-layer production solutions, multilayer flash cutting and edge bevelling, panel stacking, and pinning, as well as outer-layer production solutions, horizontal and vertical galvanic processes, solder mask, and final clean.
He commented that there are still many companies relying on manual handling to transfer product from one process to the next, and this could result in many disadvantages in addition to potential handling damage. These include order confusion and searching for specific orders, downtime due to operator unavailability, and low to no traceability.
New production philosophies will enable the realisation of targets like 100% product and process traceability, lead-time reductions by inline production wherever it is useful, automation wherever it is useful, intelligent work-in-process storage solutions with fully automatic interconnection between different process clusters, Smart production planning solutions with the elimination of manual data input and paper travellers, product tracking at all processes, and interface integration for the connection to Smart MES or ERP platforms.
Tinnefeld showed a series of examples of actual projects that have been realised, for example, direct connection of a material-logistic system with the pre-clean process, a loading station for sequential build up technology panels with integrated paper recognition, copper and panel thickness control, and DMC laser printing.
Other realised projects include an inner-layer production setup with 100% order tracking and an example of process connection possibilities by the integration of work-in-process storage solutions and automatic guided vehicles.
The afternoon session, moderated by John Fix, manager and director, marketing and sales at Taiyo America, focused on additive manufacturing and new materials. The first speaker was Bas Le Grand, process development engineer with SUSS MicroTec in the Netherlands, who explained that control on solder mask thickness can be made easy using inkjet techniques.
Having briefly reviewed the main characteristics of inkjet technology in solder mask imaging, he detailed the process sequence, commencing with front-end data input.
Once the PCB design data is loaded, the user has the opportunity to input board properties, ink properties, and pre-treatment properties, then to select the fiducials and their detection method, followed by the layer properties for the respective copper layer, solder mask layer, and drill layer—and finally to compensate for droplet size and flow out before calculating the required print layers.
The encrypted production files are then ready to export to the inkjet printer. They are compatible with multiple printers, and data for a particular PCB is selected by barcode.
The versatility of the system enables the thickness of the solder mask deposit to be varied locally as required by the particular design: none, thin, medium, or thick, wherever it is needed.
Liquid Crystal Polymer
Carina Luchsinger, R&D Engineer with DYCONEX in Switzerland, discussed applications of liquid crystal polymer as a biomaterial for neural implants.
She began by reviewing the types of electrodes used to interface the brain and the depths at which they operate. Electroencephalography records brain activity from the scalp, electrocorticography records electrical activity from the brain cortex, intracortical electrodes are inserted into the cerebral cortex, and depth electrodes are placed within the brain’s substance. Clinical applications include the treatment of tremor patients, Parkinson’s disease, cluster headaches, epilepsy, stroke, spinal cord injuries, and speechless patients.
The basic requirements for neural interfaces are for thin film substrates that match the mechanical properties of brain tissue with high spatial and temporal resolution, biocompatibility, and long-term biostability. Further requirements are for miniaturization, with surface topography that maximise contact area, low impedance, and high charge storage capacity. Typical surface coatings of electrodes are platinum and platinum alloys or poly (3,4-ethylendioxythiopene) “PEDOT.”
Electrodes are required to be capable of high resolution for recording and stimulation, and to be manufacturable at high quality and low cost.
Luchsinger reported that liquid crystal polymer has proven to be an appropriate material for neural implants. It is a flexible thermoplastic base material with a suitable elastic modulus, chemically inert under most conditions and temperature stable up to 190°C. It exhibits very low water absorption and diffusion rates and is suitable for high frequency applications up to 120 GHz. Multilayers can be fabricated from a single homogeneous material with no adhesive.
Liquid crystal polymer-based substrates with pure gold conductors have been used as neural interfaces, and the electrical characteristics of the electrodes have been matched to the requirements of the neurons in terms of impedance and charge storage capacity. Platinum alloys and PEDOT have been successfully used as surface coatings.
She is confident that liquid crystal polymer thin film technology will advance neuroscience research and enable high resolution electrodes with optimised surfaces.
With the increasing complexity of electronic systems, board level reliability becomes a critical issue. Dr. Anna Graf, marketing manager, PWB Materials with Resonac Europe in Germany, explained the principal failure mechanism and discussed how reliability may be improved using a new prepreg designed to absorb thermal stress.
Traditionally in FR-4 PCBs, the focus of attention regarding thermal reliability has been expansion mismatch in the Z-direction between the glass-resin composite and copper in plated through-holes. Graf pointed out that in soldered assemblies, an equally critical consideration is expansion mismatch in the XY-direction between FR-4 substrate and components mounted on the surface of the PCB, leading to stress cracking of solder joints—particularly with lead-free alloys.
Customers’ reliability requirements are increasing, especially in the automotive sector, which is very cost-conscious. So, the option of making PCBs on low-expansion substrates is not economically viable.
Graf introduced the concept of a stress-absorbing prepreg to form the surface layer of the PCB, which will offer a cost-effective solution. Resonac’s new material is softer than standard FR-4 with a lower elastic modulus and low XY thermal expansion. It is available in a range of glass styles and resin contents giving pressed thicknesses from 0.069 mm to 0.208 mm.
Extensive thermal cycling testing, both in-house and independently by third parties, have demonstrated that board level reliability is significantly improved, and solder joint cracking minimised by simply replacing outer layer prepreg with the new material.
PCB Material Technology Trends
Yonghyon Kim from Doosan Corporation Electro Materials Europe in Germany gave an encyclopaedic overview of high-speed PCB material technology trends, covering all aspects of glass fabrics, resins, filler systems, and copper foils, and their effects on signal loss.
Doosan offers a full range of materials for 5G applications, and their latest development is a Tier 6 product with a loss tangent between 0.003 and 0.002 at 10GHz for 800 gigabit Ethernet applications. They also have a comprehensive selection of specialist materials for HDI and automotive applications and for the manufacture of IC substrates. Kim discussed the technology roadmaps for allthe main product categories.
Solder Mask Restrictions
The final session of the first day was a roundtable discussion on the consequences of current formulation restrictions imposed on solder mask suppliers by the SVHCs defined in upcoming REACH regulations, particularly regarding key photoinitiators. Ink manufacturers Agfa Gevaert, Electra Polymers, and Taiyo America were represented, together with inkjet equipment manufacturers Notion Systems and SUSS MicroTec.
Conference Day 1 Conclusion
The convivial conclusion to an active and productive conference day began with a bus ride downtown to enjoy Lyonnaise cuisine and networking at Restaurant Le Cintra, and certain technical debates continued for a while afterwards in the hotel bar.
(The second day of the conference will be reviewed separately, stay tuned.)
As ever, I am grateful to Alun Morgan for allowing me to use his excellent photographs.