Flexible EMS partner focuses on quality with 3D AOI

The modern electronic producer currently has 24 employees with customers mainly in Switzerland, which then usually export to Germany or the United States. From start to finish, SMTEC proves to be an absolutely competent partner, who is able to carry out the work reliably according to customer specifications – from component procurement to the required test depth and assembly. They have a loyal customer base of approximately 60 customers, a large component warehouse, conformal coating equipment, rework stations, as well as, an integrated traceability system, from receiving to final inspection.

With modern technology to the
high-end product

Powerful and modern machinery ensures that all wishes of customers are produced efficiently with the highest quality. The following services, individually or combined, are available:

• Procurement of materials
• Assembly of circuit boards in SMD and THT technology
• Automatic inspection using 2D / 3D AOI
• Flying Probe
• Function test based on requirements of the customer
• Traceability depending on component level
• Assembly work right up to sales packaging
• Rework of BGA, CSP, SO-IC, and QFP

As a flexible EMS partner, the company provides its customers with competitive advantages in the market. Previously manufactured with stand-alone solutions, the company has recently converted to line manufacturing with a high degree of automation. The head of Technology / Quality Management and a member of the board, Adrian Scherer, said, “Our incentive laid in simple throughput, and we also had a large amount of manual work. We wanted to make our production go towards the Lean principle, which meant more automation. Now we have a complete line with two connected i-Pulse placement machines for our high volume series, as well as, two incomplete lines that handle our smaller lot sizes. This way, not only do we have the same output with less manpower, but the quality has also been improved by reducing manual work.”

The complete SMD process is located on the first floor of the two-story building. In contrast, next to the THT and manual workstations, the inspection of all equipment and systems is located on the second floor. Being equipped with modern high-flex placement systems guarantees shorter delivery times. The spectrum of components are covered to the full extent. The screen printing is fully automated by an optically oriented stencil printer. A gentle soldering is available by using the vapor phase system within the soldering process, which is next to the reflow oven.

Nevertheless, automation is not always reasonable or even feasible. For instance, when a service provider receives bulk material, mechanical parts, they have to be placed by hand and soldered on the PCB. This assembly is used in devices for development in the automotive industry and requires a high degree of accuracy and functionality. For this purpose, the company stands for the best quality, because all products are 100 % visually inspected before leaving the house. The final touch is the 3D AOI from Mirtec, which was acquired in the summer of 2016.

Quality ensures competitiveness

Next to the THT, in the top floor of the building, is the complete testing area. In addition to the MV-3L Desktop AOI system and Mirtec’s 3D MV-6E Omni system, there is also a Pilot 4D line Flying Probe from Seica that is only used when customers expressively wish to do so. Furthermore, various function tests with needle adapters are also available for the customer, where a customer provides the tester so this process can be carried out. The company is open to all suggestions and provides appropriately trained staff. Despite the well-equipped test area, the company decided to invest in an inline-capable 3D AOI, where a comprehensive product specification sheet was prepared in advance. After all, it should be ensured that the investment meets 100 % of the requirements. Reto May, Sales Manager and a member of the board, reported, “At the SMT 2016 in Nuremberg, we looked at different vendors to get an overview of who could offer exactly what we were looking for. After only two remaining suppliers, we approached them with problematic and complicated assembly in the production. We wanted to make sure that our requirements were met, including all theoretical possibilities of the task, as well as, a flawless working process. In the end, we decided to go with Mirtec system, which is distributed by pb tec solution GmbH in Germany. The decision was reached mostly due to the side cameras of the system, which was very important for us. In addition, we were familiar with pb tec since we bought the desktop system about 10 years ago. We knew what we were getting into, because we already had good experiences and advise at the time.”

The 3D AOI was delivered in June 2016, then installed and was already operational by July. Adrian Scherer added, “We were told exactly what we needed, which specific connections had to be available, etc. to have an easy installation process. We upgraded our server so that we were already prepared, when the large amount of data, that was generated by the system during the test, could be easily processed. The delivery was made on time, and despite our high requirements, we received a high quality training, instruction, and support on behalf of pb tec. We programed and tested our complex assemblies together in the training, so that the easy assemblies could be made even simpler.”

Also, from the pb tec side, only positive things were said, in regards to the successful collaboration, on both a personal and professional level.

Inspection relevant with process

The 3D AOI MV-6e Omni is equipped with the latest features. It has an 8-phase color lighting system (RGB and yellow, with 4x white) for perfect illumination and reliable detection of faults on the circuit boards, as in cracks or breaks in components. The high-resolution 15 megapixel top camera in combination with the four 10 megapixel side cameras ensure a clear detection of side defects, an inspection of J-Leaded components, and the identification of characters on wired components. A telecentric lens ensures distortion-free magnification of the image. The Quad-Multifrequency 3D Moiré technology measures the component in all four directions, to obtain a 3D image for fast, accurate error detection. It also ensures a shadow-free 3D representation through eight 3D projections, whereby the inspection of different levels of components is made possible through a combination of high and low frequency Moiré grids. The data-transfer technology CoaXPress achieves a 4 times larger data transfer rate and the inspection speed is approximately 40 % faster than conventional transmission technologies. The system is equipped with a stable spindle motor drive and due to its small size (1.080 mm x 1.560 mm), it fits in tightly sized production surfaces.

Adrian Scherer is thrilled with the performance of the system, “In SMT and THT processes, we assembled 5,000 circuit boards, where some had toggle switches with different positions and clamps whose direction had to be checked. These 5,000 assemblies were then tested with the 3D AOI with 100 % accuracy, and then delivered to the customer. We had no failures and every assembly worked flawlessly. This was a sign for us that the system works very well in series.”

“All assemblies that are processed by the system can be delivered directly and no longer requires manual final control. This not only saves us an immense amount of time, but also personnel costs. The results and customer feedback are convincing and very good. Also, the system goes beyond a pure test. Due to the statistics that are automatically created by the tests, I get feedback of what was incorrectly produced in my SMT assembly. With this, I am able to eliminate errors before they arise.” The company plans to start an expansion of the building late this summer. By early summer 2018, the project should be ready with an expansion of almost 600 m2, which will prepare them well for the future.

It should certainly be mentioned that the machine is both 2D and 3D capable because there are still errors that may not be detected with a 2D, but with 3D, and vice versa. These errors include, the OCR-character recognition which would only be truly recognized by a 2D system. (dj)

productronica, Booth A2.329 + A2.331

www.mirtec.com; www.pbtecsolutions.de;

www.smtec.ch