Integrated Motion Control
Applications
Semiconductor Wet Bench with SLC 500 and DeviceNet
A common application of motion control in the semiconductor manufacturing industry is the wet bench - the robotic machine for transferring the sliced semiconductor wafers through a series of chemical baths to clean and remove residue left after the slicing of the wafer from the silicon ingot. This prepares them for continued manufacturing processes of etching and depositing.
A mechanical actuator with about 1 meter of stroke is used for the vertical axis, usually driven by a ballscrew to lift the boat of wafers (typically 18, about 150 pounds) up and out of the dip tank. A longer horizontal axis, often driven by a timing belt, will shuttle the boat over the next dip tank allowing the vertical axis to lower the boat into the next solution.
The motion profile is commonly "up and over". To prevent jarring of the expensive load, manufacturers of the machines have smoothed the profile by creating a parabolic motion. This motion is repeated through three to five dipping tanks.
Rockwell Automation Solution
The robust design of Allen-Bradley servo systems, along with their inherent closed-loop nature create a strong, efficient solution for the motion control needs of semiconductor equipment manufacturers. The ULTRA 100 micro drive is an ideal solution. The ULTRA 100 can be commanded using I/O, analog command or step/direction signals from a PLC, industrial computer or multi-axis bus-based card. The extensive diagnostics capabilities of the ULTRA Master software for the ULTRA 100 is a great time saver both in initial commissioning and system support. NEMA flange servo motors are also popular because they mate with standard gearboxes or mechanical actuators from other suppliers.