There is no doubt that surface mount technologies (SMT) have been instrumental in the development of the electronics manufacturing industry. Every step carried out during the SMT process, including glue dispensing, coating, solder paste inspection (SPI) and automated optical inspection (AOI), plays a critical role in the successful production of each device. Any machine malfunction or component failure could result in poor performance or even a production halt. In either case, the consequences unacceptable to equipment suppliers and end users.
Each step of the SMT process, from PCB printing, SPI, component mounting, reflow, to AOI, imposes different automation control requirements. During the printing stage, motion control cards are used to precisely control the movement of spray nozzles. Image recognition systems can check if solder paste has been properly coated according to standards during SPI. In the case of any anomalies, an alert in the form of DIO or M2M messages can be sent to data centers for analysis. For component placement, automation
equipment is also used to control pre-heating, temperature, and reflow procedures. Image data collected during AOI need to be transmitted at a high speed without errors, which calls for image recognition systems with flexibility. These interconnected steps are all essential for an SMT process to be properly conducted.
A well-known machinery supplier based in China was developing SMT equipment incorporating industrial PCs (IPC), motion control cards and image control systems from different manufacturers and encountered serious compatibility problems. The production line was constantly plagued by minor failures such as a machine getting stuck or a screen going blank. Production was hit particularly hard by failures during AOI, which demands a high degree of precision. To overcome such reliability issues, the supplier decided to replace the IPC-the brain of industrial automation-and other critical components including motion control cards, image control systems, I/O interface and Fieldbus components all at once.