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6/30/2015 1
Discover a Novel Approach to Control of High Precision
Linear Motor Gantry Stages June 16th, 2015
Presented by Jason Goerges,
ACS Motion Control
Introducing your Moderator
Liz Wright
Marketing Manager,Motion Control Association
734.994.6088
Introducing your Presenter
Jason Goerges
General Manager,ACS Motion Control
(763) 559-7669 x131
Thanks to Our Sponsors
ACS Motion Control
MicroMo
Agenda
• Performance Requirements / Definition of High Precision Linear Motor Gantry Stages
• Applications• Factors Affecting Performance • Traditional Motion Control Solution and Limitations• A Novel Motion Control Solution and Capabilities
High Precision Linear Motor Gantry Systems: Performance Requirements
• Move and Settle– Acceleration: 2g+– Velocity: 2m/s+– Distance: Short (sub-um) and Long
(many mm)– Settling Windows: <+/-50nm p2p– Settling Time: 0 – few ms
• Idle position error (‘Jitter’)– Window: <+/-1nm p2p– Spectral Density:
• During Velocity Smoothness– Velocity: 0.1 mm/s to 100mm/s– Following Error: <+/-100nm– Time to Cover Encoder Cycle
Deviation: <1%*Performance may be measured at
motors or at chuck/DUT itself
Example Step and Settle Plot
1nm steps
±0.4nm jitter
Applications
• Advanced Semiconductor Wafer, Mask, and FPD Inspection and Metrology
– E-Beam– SEM / FIB– High Resolution Optical– X-Ray
• Lithography– E-Beam– DUV/EUV– Direct Laser Writing
• Wide Format Printing and Scribing– Semiconductor– Solar– FPD
Factors Affecting Performance
• Resonances– Stage Mechanics– Frame/Base– Cabling
• Stage Mechanics– Bearing / Friction– Force (Cogging)– Repeatability– Orthogonality – Straightness– Stiffness
• Encoder– Alignment / GPO– Noise
Factors Affecting Performance Continued
• Control– Servo Algorithm
• PID vs Adaptive• Sampling and Update
Rate
– Profile Generation
• Electronics– Power Supply– Drive Linearity– A/D Quantization Noise– PWM Noise
Linear Drives*
Traditional Motion Control Solution
Motion Controller
Communication to other devices and/or
applications
Standalone (Handling
Position/Velocity Loops and
Commutation)
Motor
Feedback
Current Commands
*Linear Drives eliminate PWM switching noise
Enclosure / Rack / Cabinet
Traditional Motion Control Solution: Limitations - Cabling
supply
Supply cableNetwork communication cableEncoder to drive cable
Motor to drive cable
Electrical cabinet
*All encoder and drive cables are ‘moving’ and are generally long
ControllerDrives
Traditional Motion Control Solution: Limitations - Cabling
• Moving cables oscillate– At low frequencies (<100Hz)– The frequency changes as a function of position
• Profile Shaping is not suitable– Oscillations can be reduced but profile time is extended too much
• Increasing Acceleration is not suitable– Induces more oscillations and increases settling time
Traditional Motion Control Solution Limitations – Drive Technology
• Linear Drives are not well suited for physically distributed architecture
– Too inefficient (too much heat)– Too large and heavy (heat sink usually
required, larger physical components)
• Solution: drives– Revolutionary PWM drive with as good or
better servo performance as linear drives– Fraction of the size of linear drives – Multiple form factors including one for
mounting on moving stages– Single and Dual Axis drives– See previous webinars or ACS website for
more details on NanoPWM
Drives*
A Novel Motion Control Solution
Motion ControllerCommunication to other devices and/or
applications
Position / Velocity / Torque Commands(via EtherCAT Network)
Standalone or PC Based
Motor
Feedback
*Single/Dual Axis Drives
A Novel Motion Control Solution
Encoder to drive cable
Motor to drive cable
DC Supply cableCommunication cable
supply
Controller
A Novel Motion Control Solution:Capabilities
• Unique MIMO Gantry Control– Decoupled control of linear and
rotational DOF– Cross axis position compensation– Suitable for stiff and flexible gantry
systems– Enabled by dual axis drive
architecture
• Advantages:– Higher Bandwidth– Better Stability– Higher Accuracy and Repeatability– Easier Tuning– Increased mechanical reliability,
reduced MTBF
Yaw Axis
Linear Axis
More Details on MIMO Gantry Controlhttps://www.acsmotioncontrol.com/videos
A Novel Motion Control Solution:Capabilities
• Reduced Cost and Improved Reliability– All cables are significantly shorter and simpler (Ethernet and DC power)
• Improved Performance– Lighter weight, reduced moving mass (possible to increase acceleration)– Remaining cables resonate at frequencies > 200Hz (possible to use Profile
Shaping)– No residual forces on the stage
Data taken from next generation wafer inspection stage (25mm move)
Settle to 50nm Settle to 10nm
Traditional Solution 110ms 120ms
Novel Solution < 80ms < 95ms
Conclusions
• ACS is proud to present an innovative solution for stage manufacturers and OEMs of next generation equipment with the most demanding performance requirements
• Based on the unique solution presented, high precision gantry positioning stages can achieve previously unattainable levels of performance:
– Higher accuracy– Shorter move & settle– Lower standstill jitter– Lower following error during motion– Lower cost of material and ownership
Questions?Contact: Jason Goerges
General Manager
ACS Motion Control, Inc.
Phone #: 952-698-1781
Thank you!
