Hanover, April 2014 – Once again, on March 19, the inspection specialist Viscom opened the annual Technology Forum and User Meeting in Hanover. This year the physicist Dr. Ulf Merbold was invited to present the keynote speech. As NASA astronaut aboard the space shuttle Columbia in 1983, he became one of the most popular German scientists. In his talk, "Science in Space", he let the audience share in his extensive experiences during his space missions. The visitor could view the Earth from an altitude of 300 km and was astonished by how many details could still be recognized. According to Merbold, not only could the central mountain ranges be seen, but also the major cities and even the steam above power plants. His report on the exciting launch from Houston and everyday life in the space shuttle was vivid and fascinating. Thus he brought the strenuousness of movement in a space suit and the high degree of preparation required for such a mission to tangible life. In closing, he admitted: "This view of the Earth has changed me." He made clear that he sees space as an opportunity which is opening at just the right time. "The chance to find out whether the Earth is able to regenerate by itself – and if not – to do something in time to leave something intact behind us for our children," said Merbold.
The audience listened intently to his accounts and it appeared they would have been delighted to hear even more. But the next presentation was also exciting, although – quite literally – a little more down-to-earth. Next Andreas Lebrecht, production manager at Vierling Production GmbH, reported on the introduction of the component type 01005. "To the question of 01005 placement, at first everyone says it is no problem," states Lebrecht and continues, "yet in Europe there are next to no electronics manufacturers employing this technology in series production." According to Lebrecht, the most significant challenges are that the current recommendations for pad design and the component dimensions of individual manufacturers differ from one another; as well, the quality of the vendor parts is extremely sensitive. In order to establish the process correctly right from the start, at Vierling the entire process chain was gone through step by step; at each step, which adaptations had to be made was checked. Ultimately it was evident that most of the process stages (solder paste print, reflow soldering, AOI, review/repair) could be carried over to the 01005 production relatively well and with only minimal effort and investment. For the solder paste print, the stencils were produced in close coordination with the manufacturer. Andreas Lebrecht describes triggering behaviour and amount of solder as acceptable and manageable with a corresponding amount of effort. During the first smaller production batches, sporadic offsets were noticed. The reflow process, however, could be released quite quickly. During the AOI process as well – Vierling employs the Viscom AOI system S3088-III – utilization of the HR function (High Resolution), slight adaptation of the inspection algorithms and the Integrated Verification permitted release of the process step to be achieved relatively easily. Only component placement was associated with greater effort. "Here, the number of feeder positions is an important criterion and the investments are not to be underestimated" said Andreas Lebrecht. In the end, in addition to a new pick-and-place machine Vierling needed 160 new feeders and the corresponding training. Revisions and changes to type 01005 components have proven to be critical and at present can be implemented by only a few employees.
After coffee and cake, the participants could return to the subject of SMT production. Prof. Dr. Armin Rahn, expert in the field of connection technology, answered the question: "What are the key issues in the reflow process?" Pin-in-Paste – or through-contacted reflow soldering – is a direct competitor to selective soldering. Many companies select the reflow soldering of wired components because they recognize their process advantages. But according to Dr. Rahn, to be successful means paying attention to a series of details reaching from layout through selection of components and up to provision of the solder needed for the soldered connections. The paste application or the use of molded parts can be managed in many ways, so this process step can be adapted to individual requirements. Many of these topics were addressed and explained during this short talk. Even the IPC has acknowledged and further supported the popularity of this procedure by a change in their requirements. Thus, how Pin-in-Paste can be successfully implemented was conveyed to the participants. Among the additional topics were: why P-i-P? How should the design look? How much solder do I need? What are the paste print options? By that point, the User Meeting participants were already able to gain a great deal of specialized information. The cost-free workshop offering contained topics such as: possibilities for raising throughput, the next generation of statistical process control, and tips for better inspection options with the help of advanced analyses. The areas of wire bond inspection and X-ray inspection were also represented by a workshop. A comprehensive offering, which once again was genuinely appreciated by those responsible for the systems.
At 5:00 PM both groups, the Forum participants and the visitors to the User Meeting, came together in Production Hall 3 to listen to the live presentation from Peter Krippner, Vice President at Viscom, and Detlef Beer, responsible for
product development at Viscom, and to conclude the first day at the traditional Get-Together.
At this year's presentation, the brand new 3D AOI system S3088 ultra was introduced to the public for the first time and compared to the performance features of the S3088 flex with 8M camera technology. Both systems were live in operation and ready for presentation. The two AOI systems share the same hardware platform, high performance linear drive, high precision grayscale value calibration and the system self-monitoring TCM. New – both for the S3088 flex as well as for the S3088 ultra – is the FastFlow handling concept. Here, Viscom has found a solution to change printed circuit boards synchronously and nearly without time loss, thus generating a considerable throughput advantage.
First Peter Krippner again pointed out the central features of the 8M camera technology which, with its resolution switchable from about 11 to about 23 µm/pixel, quickly, thoroughly and reliably covers typical defect types such as chip tombstoning, QFP with lifted leads, solder bridges or polarity. Even 01005 components or QFPs with 0.4 mm pitch can be reliably inspected. Next was the impressive presentation of the 3D AOI S3088 ultra with 3D XM module. New on the XM module is the high speed camera technology which facilitates realization of combined and completely overlapping fields of view from all cameras. With this feature, the number of positions to be moved to is reduced by up to 50 %. Also, the upper transit clearance was raised to 50 mm. One additional advantage of this high performance technology is the enormous increase in camera frame rate. Because frame rate determines the time required for image acquisition, the multiple images required for 3D image evaluation are acquired at very high speed. In a striking demonstration, Detlef Beer presented the 3D measurement with variable fringe projection, which was conducted at Viscom with one projector and four cameras. "The advantage compared to conventional approaches with four projectors," explained Detlef Beer, "is the parallel acquisition of different scenes and concurrent four-fold data rate (number of images/scenes per time unit).
Beer continued, "The height measurement range from at least 25 mm at a general inspection free space of 50 mm, with which high connectors or Tantals can be reliably measured, is also unique. With the 3D AOI system S3088 ultra, we have been able to at least double throughput in comparison with the S3088 flex." Because of this high speed, now with XM additional views or increased angled views (inspection depth!) as well as color acquisitions at full resolution also have nearly no impact on throughput. The multicolor illumination enables a high defect contrast and high flexibility within the scope of inspection. That all this is integrated into the compact housing of the S3088 series family was very convincing to the listeners. Therefore it is no surprise that several systems are already close to delivery.
After this comprehensive information on AOI technology, the participants were looking forward to the bar that was then opened. This year, Viscom also invited a local microbrewery for the bar and judging by consumption, the tastes on draft certainly pleased the visitors. The following buffet and live music again provided ample opportunity for further exchanges of experience among the visitors and Viscom experts. This year's special guests, the Hamburg brass band "Men in Blech", provided just the right mood for the later hours. The ensemble enthused the visitors with their furious performance of rousing classics from rock, jazz, soul, waltzes, and masterful brass ballet renditions. Mobile phone cameras were clicking; the first-class solos and humorous repartee were lavishly applauded. And thanks to the free shuttle service, at the end of the evening all the visitors returned safely to their hotels.
The prelude to the second day began with a case study from Prof. Dr. Gerhard Weber from the University of Vienna. The anthropologist gave the audience a look into the activity of his specialist field, "Between Desert Sand and the Micro-CT Laboratory". Prof. Weber took the listeners along on a virtual journey – to his excavations and the subsequent scientific investigations of the finds in the laboratory. Among other subjects, his report covered the excavations in the desert of Somalia which were only possible with heavily armed helpers, and the search for a 4 million-year-old elephant tusk conducted with temperatures at 40 C in the shadows. With CT visualizations and impressive animations, his superbly prepared presentation pointed out the groundbreaking knowledge which has been able to be gained recently through the use of computed tomography. For the CT investigations, the University of Vienna employs an X-ray unit on the basis of the X8060 specially manufactured for this purpose by Viscom. The spacious sample chamber and special spiral mode with extremely good resolution is necessary for non-destructive testing of large and/or long test objects such as skulls or thighbones.
Most impressive was the anthropologist's explanation of the result of research into the skull features of various prehistoric humans, which was carried out in conjunction with internationally leading laboratories and has led to entirely new discoveries. "The anatomically modern human," states Dr. Weber, "emerged about 45,000 years ago; yet the investigations indicate the Neanderthals first became extinct about 40,000 years ago. An interesting insight, supported by genetic analysis, is that the modern human and the Neanderthal coexisted for about 500 years – and most certainly encountered each other," according to Weber; "because according to the results of the investigation the modern human carries 4 – 5 % Neanderthal genes."
The next presentation returned to SMT production. Dr. Heinz Wohlrabe, renowned SMT expert from the Dresden University of Technology, reported on his latest test results to "The Optimum Soldered Connection - in the Tug-of-War between Quality, Reliability and Costs".
"The goal," said Dr. Wohlrabe, "is the minimization of solder splashes, wetting defects and voids to secure the longest average life span possible and delay initial failure of the soldered connections. To analyze and evaluate the
reliability of the soldered connections, along with other information, the measurement results of the angled solder joint inspection of the Viscom AOI systems were included in the data. Based on comprehensive tests and simulations it could be demonstrated that, for example, the alloy, volumes and distribution of the solder; the temperature rise and gradients; as well as geometry, dimensions and form of components and also the pad layout play a decisive role for the reliability of soldered connections.
In the middle of the next presentation stood the different processes of 3D measurement technology – currently an oft-discussed topic. With in-depth explanations and comprehensive functional diagrams, Dr. Taras Vynnyk from Viscom demonstrated the current approaches in 3D measurement technology for printed circuit board inspection. Thanks to many charts, the audience was able to understand the technological bases very well. In closing, Dr. Vynnyk contrasted the measurement methods with all their advantages and disadvantages to grant the listeners a good overview of the current state of this technology.
The conclusion of this lecture series featured Hans-Jürgen Funke from NXP Semiconductors, manufacturer of discrete electronic components. In addition to comprehensive information about the company's product range and its innovation drivers, Funke reported on an interesting investigation conducted together with Viscom. The focus of this interest was specially developed DFN housings (DFN: Discrete Flat No-Lead), with soldered connections that can be inspected with an AOI system. To accomplish this, the DFN housings were extended with an externally visible, wettable soldered pad edge. The purpose of the investigation was to find out what effect, in comparison with conventional housings, this technology had during inspection with AOI and AXI. The influences of process indicators such as insufficient or excessive solder paste were also investigated and illustrated in detail. As a result of this investigation, it could be determined that the AOI inspection of DFN components with wettable soldered pad edges is very possible when the right component types are used with the appropriate pad layouts and the AOI system is equipped with angled cameras.
In the afternoon, practice took center stage in Hanover. In the form of a system exhibition, all the Viscom system solutions from the various AOI systems and solutions for X-ray inspection through wire bond AOI and up to inspection of protective lacquer, were presented in the demo room. Many participants took advantage of this opportunity to be introduced to the performance spectrum of the individual systems by the experts from Viscom, or to discuss projects that were already concrete.
At the end of the day, in every respect it was a successful event for both sides – for the organizers, who were most pleased with the number and interest of the visitors and also for the many participants, who praised the concept and
1 Viscom TF: Opening, l-r, Dr. Ulf Merbold, Volker Pape, Viscom AG
2 Viscom TF: Free workshop offering, Torsten Wichmann,Viscom AG
3 Viscom TF: Presentation S3088 ultra
4 Viscom TF: System demonstration
5 Viscom TF: Andreas Lebrecht, Vierling Production GmbH
6 Viscom TF: Evening event
7 Viscom TF:Evening event 2
8 Viscom TF: Presentation of the S3088 ultra, Peter Krippner, Vice President, Viscom AG
9 Viscom TF: The speakers, l-r, Prof. Dr. Armin Rahn, Dr. Taras Vynnek, Viscom AG, Dr Heinz Wohlrabe, Dresden University, Hans-Jürgen Funke, NXP Semiconductors Germany GmbH
10 Viscom TF: X-ray workshop, l-r, Michael Fuhl, Sebastian Bolm, Viscom AG
11 Viscom TF: Midday break
Viscom AG manufactures and sells high-quality automatic optical and X-ray inspection systems. The company is one of the leading suppliers of 3D solder paste inspection, component placement and solder joint inspection equipment in the PCB assembly market. Viscom systems ensure quality in surface mount technology production lines, where they can be interlinked to further improve productivity. The company’s headquarters and manufacturing operation is located in Hanover, Germany. With a wide network of branches, applications and service centers, Viscom is represented throughout Europe, Asia and the Americas. Founded in 1984, Viscom has been listed on the Frankfurt Stock Exchange (ISIN: DE0007846867) since 2006. For more information, visit www.viscom.com.