High Precision Quality Assurance-Stamped Parts

Precision, product safety, and consistently high quality standards—these are the strict requirements Profiltech GmbH has to meet. At the same time, the company’s customized solutions demand a great deal of flexibility. In order to monitor the quality of its special tools used in the production of precision-milled profile strips, Profiltech employs high-resolution optical 3D measurement systems by Alicona. Thanks to the repeatable and traceable measurements by these systems, Profiltech has optimized its milling process and increased the service life of its tools significantly.

In the manufacture of stamped parts, using precision-milled profile strips, also called contour strips, has become a preferred production method. The strips are usually made from copper or other common millable non-ferrous alloys and their use can in many cases replace separate processes like stamping. Similarly, assemblies whose constituting elements would normally need to be produced from several strips can be manufactured more economically in one single stamping operation.

Optical 3D measurement of special tools for the precision milling of profile strips
Based in Germany, Profiltech is a world market leader in the manufacture of precision-milled profile strips. Its customers include companies from a wide range of industrial sectors, such as electrical engineering, the automotive industry, information technology and computer engineering, as well as from other high-tech areas. The company’s profile strips are used in e.g. the manufacture of connectors, contacts, and complex semiconductor components.

In virtually all of these applications, the printed strips and their fine geometries are highly customized individual solutions. Consequently, the development and production of customer-specific printed strips must be accompanied by innovative and process-integrated quality assurance.

For this purpose, Profiltech uses high-resolution optical 3D measurement systems by Alicona. Corinna Ruess, Technical Director at Profiltech: “We use special in-house-developed machines and milling cutters for the machining of our printed strips. Since 2014, we have been relying on the optical measurement system InfiniteFocus to assess the quality of these special tools.”

Profiltech’s milling tools are made of highly advanced cutting materials that are known for their extreme hardness and stability such as polycrystalline diamond.

The company’s specially developed milling technology makes it possible to produce profile strips with highly precise channels, smallest radii of 50 µm and above, and Ra roughness values less than or equal to 0.20 µm. “In order to achieve the complex and fine milling geometries and grooves of the profile strips, we use the InfiniteFocus system during both production and quality control of the finished milling tool,” Corinna Ruess explains.

Robust measurement of cutting-edge geometry and chipping
Precise measurements are carried out particularly with regard to geometry and chipping of the cutting edge. This reduces the risk of cracks and improves edge stability. Thanks to the LED ring light, edges with varying surface and reflection properties can be measured quickly and intuitively.

“In addition to the edge radius, we also carry out measurements on all other relevant edge parameters such as clearance angle, wedge angle, and rake angle,” says Ruess. “It was only when we started using Alicona that we became able to verify the almost inaccessible areas just behind the cutting edge.”

One of the many demanding customer-specific applications is the production of power LEDs. The fine geometries and extremely small dimensions of the components can only be achieved at the required level of precision by using profile strips. The trend toward ever smaller and more complex structures as part of miniaturization posed a new challenge to Profiltech. These high customer expectations made it a logical step for the company to turn to Alicona solutions. Ruess: “Tactile systems and light microscopes we used to work with couldn’t deliver satisfactory results and weren’t able to achieve the required depth of focus. Due to the close manufacturing tolerances of up to ±4 µm and ever increasing requirements with respect to the precision of our products, we decided to work with Alicona.”

Improving quality and service life of milling tools
To Ruess, the advantages of using InfiniteFocus for quality assurance are obvious: “By using Alicona systems in the edge preparation and quality assurance of our tools, we have been able to significantly increase their service life and optimize them even further.”

For Profiltech’s customers, the highly variable cross-sections of the profile strips are a significant advantage, as they allow for flexible manufacturing of thickness transitions. At the same time, close thickness tolerances can be achieved in longitudinal and cross direction during the milling process.

Technical Director Ruess describes the advantages of precision-milled profile strips: “By using our products, our customers reduce tool costs, as folding and coining during the stamping process are no longer necessary. The increased stamping speed also enhances productivity.”

Profiltech takes great care to ensure highest material quality, meaning the stamping process must not create any additional stress inside the material. Alicona’s measurement systems support Profiltech in making sure the milling does not affect tensile uniformity, hardness, and electrical or thermal conductivity across the profile width of the strip.

Additionally, it is possible to assess chipping along the edge and carry out profile-based and areal measurements of tool roughness. True-color 3D surface visualization provides a detailed view of the strip surface and makes it easy to detect faults. Potential form deviations and tool wear can be identified using difference measurement, which automatically compares the actual geometry to target geometry or a CAD dataset.

Ruess: “Putting our trust in Alicona’s products for quality assurance was justified. With the support of their systems, we continue to provide the safest and most precise solutions to our customers.”