What are the key influences on quality?

The manufacturing processes are complex and demanding. Numerous production steps, which take several months, are required to manufacture a microchip. Each individual step and its parameters are monitored in order to achieve the highest possible yield. Mechanical stress is a critical factor that can damage the wafer and the microchip during numerous production steps. This occurs, for example, in front-end processes such as grinding, polishing or delamination of the wafers as well as in back-end processes such as bonding, sorting and testing in semiconductor production. Mechanical stress can lead to invisible damage such as fine cracks. This damage can reduce the reliability of the products. The reason is that the applied force changes due to wear on machines and servo motors or minimal variations in material properties. Dynamic force measurement is therefore an important step in detecting and compensating for these deviations.

What distinguishes dynamic force measurement from other quality assurance methods?

Optical measurement technology and the final testing of the semiconductor products produced contribute significantly to a high yield. Sensors for dynamic force measurement, on the other hand, make it possible to detect additional invisible deviations in the forces acting at each production step. In conjunction with the evaluation electronics, the forces can be controlled, monitored and then documented and further analyzed. Above all, however, the data can be used to further optimize production processes in order to increase yields.

In addition to improving quality, the industry is always required to come up with innovations. What trends is dynamic force measurement promoting?

Every user can observe how smartphones are becoming ever thinner, but at the same time ever more powerful. The microchips required for this with their conventional production methods are reaching their limits here. New manufacturing processes, for example in advanced packaging, require extensive process monitoring. This is where Kistler's force sensors come into play. They are based on the piezoelectric effect, which enables particularly precise and highly sensitive measurements. Industry insiders agree that additional measurement technology is needed to further increase the process reliability of the new manufacturing methods.

What feedback have users given so far?

Better process control is of the utmost importance to customers. Especially in a time of chip shortages, it is necessary to further increase yield and reduce waste. The technology helps here. For example, the measurement data can be used to trace every manufactured article, which is of particular interest to the automotive industry. At the same time, the technology helps to increase productivity. Force sensors in conjunction with servo drives enable higher process speeds with consistent accuracy. This gives users the opportunity to explore the limits step by step in order to achieve the best possible machine efficiency.

The high degree of system integration of the force sensors calls for close coordination with the customer. How does this work?

Our customers are series machine manufacturers for the production of semiconductors. Depending on their size, they produce between 20 and 200 machines per year. We discuss the best way to accommodate the sensor technology with our customers as early as the design phase of the systems. Each machine model is different and requires its own consideration. We see ourselves as consulting engineers who help customers to integrate measurement technology and thus achieve a competitive advantage for their systems.