Through-hole subcomponent leads insert into board holes, get trimmed and clinched, and then get soldered to the board backside for top mechanical strength (though necessitating more complicated assembly routines). In contrast, SMT subcomponents accept maximally automated high-volume set and solder routines … so they now dominate many board designs. That said, through-hole mounting is still most common for attaching large capacitors, transformers, and connectors to boards. For SMT components, solder paste is pre-applied to the PCB before component assembly. Reflow soldering then uses hot air to melt the solder paste to form the SMT component connections. Wave soldering is more common for through-hole components; this involves passing the board across a standing wave formed on the surface of a pan of molten solder. Such machines are costly and best suited to very high-volume manufacturing. Typical motors and drives for cartesian robotics Cartesian robotics use many of the same types of servomotors, precision gearing, and electromechanical drives as other robotics solutions. One
Figure 12: Machine-vision feedback often informs cartesian system responses. Massive onboard processing power, advanced algorithms, and an FPGA let HAWK smart cameras (including the model shown here) achieve real-time trigger response for code reading, verification, inspection, and guidance for 4,000 to 14,000 parts per minute. In fact, this camera is an intermediate solution between complex PC-based cameras and basic industrial smart cameras. (Image source: Omron Automation and Safety)
caveat is that the stepper motors in some cartesian designs that transport semiconductors during production shouldn’t be confused with so-called step-and-repeat cameras — sometimes simply called steppers. The latter are essential to photolithography processes during chipmaking. Just as SCARA and especially six-axis robotics have made increased use of direct-drive torque motors, cartesian robotics have (in designs to serve the
semiconductor industry) made increased use of linear motors in recent years. A variety of industry-standard and proprietary motor coils, miniature end positioners, piezo-based adjustment modules, vacuum and cleanroom-rated subsystems, linear bearings, controls, and other innovations complement these direct drives to help cartesian systems output ultra- fine ultra-fast motions.
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