Automation of manual optical inspections in focus
During the manufacturing of electronic assemblies, the quality of the products is ensured by a variety of inspections. The goal is to detect deviations in the process as early as possible. Only in this way can high costs for rework, "serial errors" or even complaints be avoided. At the same time, tests are being carried out optically at the beginning of the production process. Many of these optical inspections are the responsibility of visual inspectors, who carry out the assessment of the assemblies manually. CCS Schweiz AG uses the inspection system EFA Inspection, which specifically supports the vision inspectors and thus ensures process reliability and time savings.
appeared in the Productronic 5/2014
As part of CCS Customer Care & Solutions Holding AG, CCS Schweiz AG is a leading Electronic Design & Manufacturing Services Partner. With locations in Switzerland, Germany, China, Hong Kong and Sri Lanka, CCS offers an optimal production structure for the diverse tasks of the customers. The Swiss site in Lyss has over 2,000 square meters of production space with state-of-the-art machinery. The location of the location guarantees customer proximity and thus fast and uncomplicated ways during development and production. Special customer teams are available for customer-specific projects - also for the production of prototypes, pilot and pilot series.
At the beginning of 2011, CCS Schweiz AG was looking for effective support for the first sample inspection. The aim of this test is to reliably detect deviations in the assembly before the start of series production. So far, the initial sample inspection has been carried out manually by searching, comparing and evaluating from the present component list, component by component on the board. Depending on the amount of components installed on the board, such an initial sample inspection sometimes took several hours to complete.
This process takes advantage of the great wealth of experience of the visual inspectors, but is due to the manual process extremely error-prone. Small distractions or fatigue can lead to missed mistakes. After that, there is uncertainty as to whether all components have actually been assessed correctly. Above and beyond the lack of traceability and logging, the high time spent searching for components on the board has a negative effect on the process. During the time-consuming manual test, the finished line waits for production release. This costs a lot of valuable process time.
Automation of manual optical inspection
The CCS Switzerland AG evaluated several systems and decided after a short test phase in June 2011 for the solution EFA Inspection of the LEBERT Software Engineering.
“The first thing that impressed us was the ease of use,” explains Mr. Lempen, employee in the Production Engineering, Test & Final Assembly department.
The creation of programs in EFA Inspection is very easy. The data can be used exactly as it is already available for the production machines. The programming itself takes less than 5 minutes. During programming, the placement data (coordinates, article number, component designation, values, etc.), the placement plan and a recording of the first board are integrated. All this information is then available in a bundled form. The examiner is guided through the inspection. Gradually, all components are displayed to him together with the information available from the placement plan and the component list. (according to screenshot 1)
“This guided inspection gives us the assurance that the inspector has examined and assessed every component. No elements can be forgotten ”, emphasizes Mr. Lempen this function.
The evaluation is carried out by the operator and thus uses the diverse experience and flexibility of the visual inspectors.
In addition to the usual procedure of the initial sample inspection, in which component by component is considered, a test according to part numbers can also be performed in EFA Inspection. For this purpose, all components are sorted according to part numbers and components with the same part number are shown next to one another. In the display, the components are then rotated back to zero degrees according to the stored rotation angle. One of the elements is checked in detail in the main window, for example by overlaying the schematic drawing. For the remaining components with the same item number, it is sufficient to compare them with the previously thoroughly checked element. This enables the presence and alignment of all components with the same part number to be inspected very quickly. Checking from item number to item number is significantly more time-saving than checking the individual components. (according to screenshot 2)
With a total of 7 different inspection types and many individual setting options, EFA Inspection can be optimally integrated into the established process. The program itself can thus be used in a variety of ways and flexibly adapted.
"There are hardly any limits to the possibilities of integration into the existing production landscape," emphasizes Mr. Lebert, Managing Director of LEBERT Software Engineering.
“EFA Inspection is also constantly being further developed. We also implement individual adjustments in data integration, the connection to existing MES systems or even extensions to the functionalities of the software very quickly. "
After the complete inspection, a test report can be generated. Alternatively, the results can be transferred to the existing MES system.
Process reliability gained
With the introduction of the system, CCS Schweiz AG was able to drastically reduce the times for the initial sample inspection. With up to 2500 components on one circuit board, the time savings are well over 50% - many customers even speak of time savings of up to 80%. This has a direct impact on the entire lead time of a product. Not only can more be produced, the process itself has also become significantly safer.
"With EFA Inspection we were able to achieve significant time savings together with a significant increase in quality and process reliability," says Mr. Lempen, describing the successful use of the system.
The Inspection System EFA Inspection offers not only the use for the first sample inspection but also possibilities for the automation of optical inspections in the field of small series, prototypes and set-up controls. With various functions and options such. For example, surveying, utility function, fiducial recognition, golden board function, automatic loading and automatic result export, the manual optical inspection process can be automated exactly as the existing process demands.