Olaf Thomas Johan Antonie Vermeulen

Sensor and control electronics for an industrial 3D laser scanner

This paper describes the machine concept and electronics of a new industrial 3D laser scanner for 100% measurement of solder paste deposits in an automated PCB assembly line. The throughput of the system can be optimized for the product type by the flexibility of scan speed (more than 1000 scans/sec), resolution (up to 20,000 pixels/scan line) and data rate (up to 10 multiplied by 106 samples/sec). Sensor electronics involve customized position sensing detectors and low noise high speed amplifiers. Analogue preprocessing of the PSD signals guarantees a large dynamic range. The vision module simultaneously processes height and intensity data. The control electronics realize a precision synchronization of the PCB transport and an extremely stable but fast pullable pixel clock to the rotating polygon mirror. Modular parallel image processing is performed to produce data of the solder deposits such as volume, area, height, registration and bridging.