H2W introduces a fully vacuum compatible four axis positioning gantry (XYθZ). The XY axes are driven by brushless linear motor DR Positioning Stages. The θ axis is a worm gear stage that is driven by a rotary stepper motor under closed loop control in conjunction with an arc-segmented linear encoder. The Z axis linear motion is achieved by using a voice coil positioning stage operating under closed loop position control.
The four axes operate under synchronized position control in conjunction with a non-contact analog output position feedback device that is used to control the position with respect to a silicon wafer. The stage includes a fully integrated four axis electronics package that allow each axis to operate under closed loop control.
All components were selected for their low outgassing characteristics and the system was designed to fit within a customer designed vacuum chamber. This gantry was designed to perform secondary processing procedures on a silicon wafer while exposed to a vacuum.
The XY axes are driven by three-phase brushless linear motors and are guided by a pair of precision recirculating linear ball bearings. The stage has a (XYθZ) 6" [152 mm] x 6" [152 mm] x 20° x 1" [25 mm] stroke, generates (XYθZ) 20 lbs [88 N] x 20 lbs [88 N] x 10 N-m x 10 lbs [44 N] of continuous force, and (XYθZ) 60 lbs [264 N] x 60 lbs [264 N] x 10 N-m x 30 lbs [132 N] of peak force. The linear axis resolution is 0.2 microns and the rotary axis resolution is 0.29 arc-seconds.
Coordinated four axis control
Vertical orientation - Rotary axis is capable of full 360 degree rotation