9JUNE 2024their influence. Furthermore, users should provide good cable insulation and route and compensate the Reset/Operate jump, for instance, with the maXYmos evaluation system from Kistler or a PLC. Inline measurement ­ i.e., when force sensors are mounted in the mechanical structure of the semiconductor equipment ­ offers essential possibilities. Together with the charge amplifier and process evaluation unit, inline sensors enable users to record and assess the applied force. Last but not least, they can optimize the production process based on the collected assembly data. As inline measurement chains allow for measuring and recording the force of every production step, they are suitable for the automatic inspection of mass-produced items. This also entails traceability for each produced item.Achieving accurate measurement resultsResolution is defined as the ability of the measurement system to detect and faithfully indicate small changes in the characteristic of the measurement result. As mentioned above, PE sensors achieve high resolution by nature. Even with forces as low as 1 N, PE force measurement is able to achieve resolutions of less than 0.01 N in industrial applications. In addition, PE measurement comes up with quality levers such as repeatability or serial precision, which determines the accuracy of repeated measurements between identical production steps. Users can take advantage of this and use relative instead of absolute measurement. Force measurement in semiconductor processes In the past, piezoelectric force measurement technology was mainly used for machine verification and highly accurate wire bonding, wafer grinding, and polishing. Today, the technology is used in a growing number of applications throughout the semiconductor industry ­ in front-end and back-end processes as well as in testing processes such as sorting and taping (see table 1). The complexities of semiconductor production processes will increase even further in the future and require significant effort to improve the quality and yield of manufacturing. Dynamic piezoelectric force measurement is the technology of choice for meeting these requirements, offering high resolution and repeatability even for low forces. Manufacturers profit from the sensors' long lifespan and compact sizes. The benefits for the production itself are manifold: it improves machine performance regarding speed and accuracy, increases the quality of the produced items, thus reducing the ppm failure rate, and ultimately decreases costs. Deviations in the applied force during these processes mean mechanical stress and can lead to quality issues
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