Surface Inspection Don't Look Twice — Look Smart: Quality Control Made easy
How surface inspection with smart view optimizes quality control — From sporadic breakdowns to quality impairments — production processes have to deal with a wide variety of possible quality hazards. Taking a closer look is therefore definitely recommended. In fact, optical systems can identify and classify defects in production processes quickly and thoroughly.
The diversity and miniaturization of electronic components is only possible thanks to small copper components known as lead frames. The production of these precision-stamped parts places high demands on the raw material. In addition, these delicate component carriers require copper strip with a virtually perfect surface. Wieland-Werke, one of the global leaders in the manufacture of these products, relies on the Smart View Surface Inspection Systems from Ametek Surface Vision throughout its sites.
If steel is the backbone of the modern world, then its lifeblood, electric current, flows through billions of miles of copper cables. Many of the items that we take for granted — smartphones, photovoltaics, communication and mobility — are only possible thanks to copper lead frames. The continued trend of these devices towards miniaturization requires increasingly high-grade materials. These materials, made from miles of copper strips, must be defect-free, even down to the micron level.
25 Systems Provide Real-Time Surface Inspection
It’s for this reason that Wieland-Werke puts its trust in Ametek Surface Vision’s Smart View range of surface inspection systems. These units not only ensure outstanding product quality, but also accelerate and optimize the manufacturing processes. As an industry visionary, Wieland introduced its first automated surface inspection systems as far back as 1994.
Today, a total of 25 Smart View systems are installed at Wieland plants around the world, including ten at its main production plant in Vöhringen. This case study reviews the installation on the DO50 continuous furnace, focusing on the practical operation and capabilities of the system.
Copper is not just copper. Today, almost every one of Wieland’s customers requires bespoke solutions to meet the demands of their products. Hence, the plants must be incredibly flexible, producing strips with a wide range of technological, physical and geometric properties. This means that several hundred different recipes are processed in the continuous furnace, often on the same day. They possess a multitude of customer-specific characteristics, such as thickness, bendability, tensile strength and surface finish. With line speeds of up to 100 m/min, effective quality control is only possible with an automated surface inspection system.
Bright and Dark Field Views
Using Smart View, any irregularities that occur in the manufacturing process can be systematically and reliably detected and classified. Typically, two types of defect are detected:
- Systematic, repeating defects, e.g. roller imprints arising from surface damage or dirt.
- Sporadic defects, such as breakdowns caused by impurities from the casting process, emulsion residues or dirt.
To achieve this, a custom recipe for each product type, with dedicated inspection parameters, is stored and reloaded each time the product is manufactured.
The Smart View system has a specific optical and mechanical configuration to enable installation within very tight space constraints. It is installed at a space-saving deflection unit, using an S-Roller to enable two bright field and two dark field cameras to monitor the top and bottom surfaces of the strip. The cameras and lighting modules are mounted in dedicated, robust housings to protect them from the environmental conditions.
An 8 mm light strip is projected directly onto the strip and then cameras are aligned to view this area from different angles, to provide both bright field and dark field views. As with all Smart View systems, the system relies on industry-proven line scan cameras that ensure that even the most minor defect on the 800 mm-wide strip does not escape the automatic eyes! The synchronization of the bright field and dark field cameras results in the best possible detection of irregularities. The combination of the upper and lower surface inspection provides additional characteristics.
Synchronised Camera View Provides Optimum Process Insights
Thanks to high-performance line scan camera technology, the use of synchronized camera views for each application provides the optimum combination. This allows the flexible use of a number of different configuration and inspection angles. The configuration of Wieland’s DO50 is described by image processing experts as synchronized view processing. As outlined above, two lines of bright field and dark field cameras are installed. This means that even the most diverse of reflection properties can be reliably identified. Because Smart View combines the bright field and dark field defect patterns in real time, defect types can be accurately classified.
Smart View’s advanced processing software enables an automatic detection and classification of surface defects based on pre-determined parameters. This also ensures that acceptable surface features are not falsely detected. Once the defect has been detected and classified, it is presented to an experienced operator to assess the defect pattern in detail. The entire process of image capture, image analysis and data exchange takes a split second. In this way, positional data, the grayscale value, orientation axes and segmentations are combined as a defect-specific data packet. Overall, Smart View determines a unique set of characteristics for each defect pattern. The data is transmitted once the final process step has been completed.
Unlike the first surface inspection systems used at Wieland, which was a costly customized solution, today’s standardized, “off the shelf” Smart View systems provide effective, cost-efficient defect detection across the entire company. The flexible system is the result of more than 20 years’ research, development and experience in selecting the right combination of industrial cameras, variable lighting and high-performance image processing software. Wieland uses a total of 25 Smart View surface inspection systems worldwide.
A Closer Look on Quality Control
These are identical in terms of structure but are individually optimized to the specific application. This combination of standardization and customization reduces both the upfront purchase costs (compared with a bespoke solution) and the cost of start-up, maintenance and worldwide data exchange. Wieland can therefore put its trust in a reliable and fast surface inspection at all production sites throughout the world. With these systems, Wieland’s products meet the highest quality standards, regardless of whether they are produced in Vöhringen, Villingen, Langenberg, Birmingham, Wheeling or Singapore.
Not only does Smart View identify and classify defects quickly and thoroughly, it is also easy to set up, thanks to its sophisticated, intuitive configuration. By utilizing these tools, the Project Manager from Ametek Surface Vision can have the system up and running a short time after the mechanical installation is complete. From there, the operators can easily maintain the system and adjust it to many different operating conditions.
You will find more information in Ametek Surface Vision's brochure.