21st EE College: SMT production today

2022-07-02 06:21:04 By : Mr. kong kingllen

Buzzwords such as miniaturization, digitization and electromobility have been floating around in the electronics manufacturing landscape for years.Although many production-related hurdles have been successfully overcome, there are still challenges that need to be overcome.With the 21st edition of the European Electronics Technoloige College, EE College for short, the organizers wanted to position themselves as holistic solution providers.21st EE College: Hans Bell, Head of Research and Development at Rehm and moderator of the specialist conference.(Image: Marisa Robles)Hans Bell, head of research and development at Rehm and moderator of the conference.Marisa RoblesCut-throat competition is in full swing and it's tough.Terms such as process optimization and efficiency hang over the heads of electronics manufacturers like the sword of Damocles.A further complication is that there is no golden middle way to unrivaled success, but different solutions can lead to the goal.And this has to be determined, analyzed and finally implemented.The organizers of the EE College, ASM Assembly Systems, Asys Group, Balver Zinn, Christian Koenen, Kolb Cleaning Technology and Rehm Thermal Systems, want to lend a helping hand - in the form of a top-class conference with well-founded specialist lectures depicting the SMT value chain and as networking platform.This year's conference covered everything from printed circuit board production, the printing process and soldering technology to challenges such as electromigration.Parallel to this, user reports had a network character.The importance of printed circuit boards at this year's conference was shown by the organizers by not only inviting experts from Contag and Emtech as speakers, but also addressing topics such as cavity and corrosion (ECM).After all, the printed circuit board is and remains the backbone of an electronic assembly, albeit often underestimated and yet indispensable.Undoubtedly, over the years it has become a very complex element of electronic assemblies.Christian Ranzinger kicked off the series of lectures.He made it clear what the green plate has to do today.In his function as Technical Director of Contag, he is responsible for technology, R&D, production and work preparation and therefore has to cover a wide range of requirements.The printed circuit board manufacturer is at home in all common sectors and must therefore be able to reliably operate all technologies.Complex printed circuit boards with 70 µm line/space and drilling diameters of 100 µm are state of the art, explains Ranzinger.The shrinking process continues: “The high-end printed circuit boards with 50 µm fine structures are no longer a rarity.And in the R&D context, interposer technology is making waves as it now connects the once separate worlds of board and semiconductor.”Speakers on the first day (from left to right): Prof. Dr.Christian Faber (HS Landshut), Christian Ranzinger (Contag), August Huber (Dräxlmaier Group), Dr.Hans Bell (Rehm Thermal Systems), Karsten Dierker (Tonfunk Ermsleben), Thomas Mückl (Zollner Elektronik) and Peter Fischer (Enmech).Marisa RoblesThe know-how of a printed circuit board manufacturer is characterized by the fact that it is able to combine not only the most diverse areas of application, but also the product types and designs - i.e. materials, construction variants and structures/layout density - into a reliably functioning circuit board.With more than 1000 active customers in all industrial sectors, Contag has built up a great deal of expertise in printed circuit board production during its more than 30 years of existence.The portfolio ranges from simple circuit boards and highly complex multilayers up to 24 layers, through flexible and rigid-flexible circuit boards to HF circuit boards and 3D MIDs."What they all have in common is that all of these printed circuit boards have a final surface finish on the copper structures," explains Ranzinger.The predominantly selectively applied surface protection has the task of ensuring a high level of process reliability with a large process window and at the same time reducing the risk of corrosion.However: "There is no such thing as a universal and optimal printed circuit board surface," he emphasizes, referring to a well-established surface spectrum that ranges from OSP (Organic Surface Passivation) to HAL/HASL (Hot Air (Solder) Levelling) to variants of nickel/gold, tin, silver, gold to carbon printing and resistance printing.“All of these surface qualities have their justification, of course always associated with a certain process risk.Both the circuit board manufacturer and the electronics manufacturer must know when which surface is suitable.In the event of an error, he must be able to draw conclusions about the causes,” he affirms, also with a view to the fact that the surface processes are also constantly evolving.Surfaces such as ENIG, ENEPIG, ISIG, etc. are becoming increasingly attractive. "Immersion" is a brewing process, while "Autocatalytic" is an autocatalytic or reductive process and "Electroless" is an electroless deposited surface.Which process areas are used worldwide?In 2016, the process provider for chemical surfaces MacDermid determined that the very inexpensive and therefore attractive for consumer electronics OSP (51 percent) is the first choice worldwide, followed by the well-established, very planar and fine-pitch-suitable surface ENIG (16 percent).Immersion tin (14 percent), immersion silver (10 percent) and HAL/HASL (8 percent), which is becoming less and less important, follow.There are good prospects for the modern ENEPIG surface, which is on the up and which currently only occupies 1 percent of the world's printed circuit board space.Based on reliability studies, Ranzinger explained the advantages and disadvantages of the respective surfaces and at the same time presented the relevant standards for the circuit board manufacturer from a surface perspective.Concentrated information on 70 slides - presented in just under 45 minutes: Peter Fischer, responsible for the process development at Enmech, bubbled out his extremely well-founded knowledge.The company, which is primarily active in the automotive industry, sees itself as a development partner and manufacturer of mechatronics based on flat conductor technology.Flexible printed circuit boards form the basis for the mechatronic products.These are 25 to 75 μm thin, flexible foils made of PET (polyester), PEN (polyethylene naphthalate) or PI (polyimide), which are bonded over their entire surface to copper with a thickness of 18 to 105 μm.The circuit pattern of the copper is produced by an etching process using the roll-to-roll method.Single-layer, very large circuits of 100 cm x 50 cm do not pose a problem here. Thanks to the high-precision manufacturing process, which Fischer calls "the ballet of roles", Enmech, which belongs to the Mektec Group, can implement conductor track widths of up to 100 µm.Ines Brune-Krok from Krüger & Gothe gave a lively presentation of the challenges the operator has to master every day in her presentation "Solder paste printing from the operator's point of view -- learning from mistakes".RoblesThe flexible, printed circuits have proven particularly useful for implementing a large number of signal connections in a small area, such as antennas: "Today, up to 22 antennas are installed in a mid-range car, with every available installation space being used," describes Fischer, one of the major areas of application for flexible printed circuit boards.However, Enmech has also further developed this technology for interconnecting individual battery cells in electric and hybrid vehicles.The assembly technologies enable the easy integration of temperature sensors, fuses and other electronic components.In addition to the power connection of the cells, these modules also offer a voltage tap for detecting the state of charge and for charge balancing of the individual cells.Protection against short circuits integrated into the modules and sensors for monitoring the thermal load increase the safety of the system.These battery wiring modules are dimensionally stable but still very flexible structures that are manufactured with high process reliability and low tolerances and can be individually adapted to customer requirements.In order to achieve this, Enmech not only has five SMT lines, but also uses various processing technologies such as crimping, riveting, laser ablation as well as ultrasonic, laser and resistance welding.He presented all these procedures in detail and knowledgeably.Fischer pays particular attention to the plug-in connections: “We attach the contacts required for this individually in a permanently monitored and automotive-compatible crimping process.Our process enables a highly reliable and gas-tight electrical crimp connection.” The assembly of (sealed) housings completes the plug-in connection.Looking to the future, Peter Fischer reported on the first successes with silver sintering technology and photonic soldering.High-performance light pulses in the millisecond range make it possible to melt the solder paste extremely quickly.The fact that the heating only takes place on the surface and therefore the foil is not heated makes this soldering technique attractive for the temperature-sensitive PET foils, which do not tolerate a reflow process."Initial experiments with our research partner are promising," sums up Fischer.Theory and practice shook hands in a balanced manner during the two-day conference.Michael Matthes, Senior Expert R&D New Electronic Technologies/EDA-Systems at Wittenstein Cyber ​​Motor, gave a diverse insight into various potential errors in electronic assembly production in his presentation "Product requirements for the solder paste application... from the component system to the assembled product".At the same time, he used the Fitbone extension intramedullary nail to demonstrate the convertibility of the printed circuit board to become an embedded component.This is an intramedullary lengthening system for extremity lengthening in the femur and tibia.The lengthening intramedullary nail has a receiver coil and is implanted in the bone in a minimally invasive manner.To activate the distraction, the patient places the transmitter head with the integrated transmitter coil directly on the skin.The contactless energy transfer between the transmitter head and the receiver coil of the implant uses electromagnetic fields to supply electrical energy to the electronics in the intramedullary realignment nail.Just over 120 participants accepted the invitation to Mallorca.The motto of this year's conference: "SMT -- State of the Art Manufacturing Today".RoblesThe implementation resulted in the design development of the Embedded Planar Inductance, EPI for short.The new design was implemented in cooperation with Würth Elektronik's embedded component technology division.Together, both partners have realized a 24-layer coil with around 170 turns as a printed circuit board.Two different, opposing cavities, which were produced by depth-controlled level milling on the top and bottom, offer sufficient assembly volume to arrange active and passive components in the center of the coil within the cavity.The greatest challenge, however, was applying the solder paste, reports Matthes: "The 3D stepped template that was originally the focus of attention was ruled out as unusable because of the additional area required to move the squeegee in and out with the cavity, which is up to 2.3 mm deep the assembly would have been almost 40 percent larger.” Cost-intensive options such as the pin-dip process were eliminated in the pre-selection, so that dispensing or jet printing were the options."Ultimately, jet printing delivered the most reproducible and fastest result."Karsten Dierker from Tonfunk Ermsleben also reported on practical experience with his lecture "A small dot on the circuit board - a plus point for the BG, SMD bonding".He clearly showed which methods of adhesive application are used at Tonfunk.For this, the EMS uses various systems such as the DEK Stinger, a precise dispenser with screw conveyor, as well as the Siplace G2 glue dosing system with three glue application heads, which is a bit outdated but delivers perfect results, and the Siplace Glue Feeder from ASM Assembly Systems.Adhesive dots or additional paste volume or paste dots are also applied to the circuit boards manually.The EMS uses Loctite glue.Karsten Dierker presented the advantages and disadvantages of the various methods.Zollner Elektronik has 70 SMT production lines in use worldwide.The electronics manufacturing service provider is therefore aware of the pitfalls of special processes that need to be handled.For Thomas Mückl, Director of Global Engineering at Zollner Elektronik, there is no question that simply assembling components is no longer enough: “The trend towards special designs continues unabated.Because of the diverse requirements, the development of special equipment or a complete process is often the decisive factor.” He illustrated what this means in practice using case studies.In addition to the placement of an asphere on assembled LEDs in a matrix, the assembly of a connector with a "press-in zone" and a contact pressure of 120 N as well as the assembly of customer-specific ceramic components and special shapes posed a challenge that made special constructions necessary.Speakers on the second day of the conference (from left to right): Dr.Hans Bell (Rehm Thermal Systems), Michael Matthes (Wittenstein Cyber ​​Motor), Ines Brune-Krok (Krüger & Gothe), Dietmar Birgel (Endress+Hauser), Josef Steuer (Neways Neunkirchen), Dr.Vinzenz Bissig (Thermission) and Günter Grossmann (EMPA).Marisa RoblesThe processing of a Hall sensor turned out to be particularly challenging.For this purpose, a 32 mm special feeder was developed with a supplier, which enabled the processing – i.e. separation and bending – of the component according to the specifications and the provision of the component for collection from the placement machine.Zollner has also gained experience with extra-long and extra-heavy printed circuit boards.For the boards, which are up to 1500 mm long or weigh up to 13 kg, the usual SMT processes had to be supplemented by handling adaptations, so that a 45.5 m long SMT line was set up for the XXL boards.The extra heavy blanks managed with a system length of 40.11 m.August Huber, Head of Industrial Engineering at Dräxlmaier Group EKB Elektro-u.Kunststofftechnik Braunau, took the participants to "Internal logistics in SMT - Industry 4.0".When it came to expanding production about two years ago, the top priority was to optimize processes and logistics.“There are four success factors for products: variability, quality, speed and cost-effectiveness.This is the only way to place products successfully and competitively on the market,” he explains.For production, this means maximizing delivery reliability and capacity utilization and minimizing throughput times – in conjunction with optimal availability of the systems and set-up sequence.He sees the three terms mura (imbalance), muri (overload) and muda (waste) developed by Toyota as the credo for the lean principles.They are closely related.Muda is often present as a buffer to compensate for Mura.This means that traditional lean actions that only minimize muda without also minimizing mura can result in extra muri, which in turn can lead to another type of waste.With smart, easy-to-achieve goals, you can set up an optimized lean production, he assures.But no electronics production can do without inspection, which is why Prof. Dr.Christian Faber from the Landshut University of Applied Sciences, sensor technology and image processing, not only pointed out in his entertaining lecture "AOI in production" that the assembly inspection serves to identify errors (QA), avoid errors (QM) and process optimization (SPC).He showed the special features of the AOI, the pitfalls that error detection can have and presented the various methods of imaging optics.The second day of the event was characterized by the challenges related to soldering technology.Josef Steuer from Neways Neunkirchen gave numerous tips on storage conditions and processing instructions.After all: In Neunkirchen alone, the EMS processes 1.5 t of solder paste annually and the trend is rising.In order to ensure an uninterrupted cold chain, the company has developed its own FIFO screw.Team spirit should be invoked when building beach castles -- a large portion of ambition was also developed in the process.Marisa RoblesInes Brune-Krok from Krüger & Gothe showed what the operator on the SMT line has to deal with when printing solder paste and what difficulties this is sometimes associated with.She knows from her own experience: "Solder paste printing is at the top of the process chain and also has the greatest influence on the error rate." She therefore gave numerous tips and finally remarked: "Small parameter changes can have a major impact on the printing result.You just never stop learning.” Dr.Vinzenz Bissig, Managing Director of Thermission.The expert, who came from Kirsten Soldering, pointed out that the THTs would continue to have their justification in electronics production - even if they were more likely to be found in niche applications.He also slowed down the hype about bismuth solders, since these are only suitable for certain applications.Endress + Hauser processes more than 3 million assembled and tested printed circuit boards and 300 million electronic components per year.It was therefore easy for Dietmar Birgel from Endress+Hauser to give a lecture on the "Influence of the SMT process on the final properties of devices".Finally, Günter Grossmann from the EMPA Swiss Federal Laboratories for Materials Science and Technology in Dübendorf, Switzerland, warned to be careful with "migration and corrosion in electronic assemblies".Using many examples from nature, he clearly explained what corrosion means and how it can occur on the assembly.Each team was proud of their sandcastle that was finished before the rain.RoblesI have read the terms and conditions, the information on the right of withdrawal and data protection and accept them.By registering, I accept the terms of use of the portals in the industry media network.I have taken note of the data protection declaration.With the combination of Keysight's cloud-based test automation platform and Sauce Labs' device cloud and software platform, users can automate the testing of digital journeys across all possible devices.Read more...In a race, the driver steered a car with only head movements and by inhaling and exhaling.The next step in this semi-autonomous Arrow SAM Car is a face recognition-based steering system.A prototype already exists.Read more...Cognizant Mobility introduces xRPA technology, which uses artificial intelligence and bots to autonomously test vehicle software.This increases the utilization of the test benches and saves process costs.Read more...SUSS MicroTec Solutions GmbH and Co. 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