- OEM / SystemsOEM Systems | Precision Components | Automation Sub-SystemsPI offers 1000’s of proven, off-the-shelf precision motion products that can be quickly modified for the OEM or into a custom automation sub-system.
- Meeting the Demands of OEMsOEM Systems | Precision Components | Automation Sub-SystemsPI has a long track record of working with OEMs in the most demanding industries from Semiconductor Technology to Medical Design – industries where product performance, quality, and the ability to ramp up quickly are not the only parameters required to satisfy the customer's demands. Working with technology leaders all around the world forces you to continuously improve your yield, process, and product performance. And unless your quality is outstanding, you cannot become a key supplier to major US, European, and Japanese companies in the Optics, Photonics, Semiconductor, and Automotive industry.
- Engineered Motion / Automation Sub-SystemsPrecision Automation Solutions | Engineered SystemsPI is a supplier of high-end precision motion systems and makes use of own drive components and high-precision positioners to build customized positioning and automation sub-systems —“motion engines”—for our customers. With the largest portfolio of precision motion technologies in the industry, PI engineers have the best foundation to find a solution that matches your requirements in terms of precision, quality and budget – in a timeframe that works for you.
- Meeting the Demands of OEMs
- ProductsPrecision Motion Technologies | Positioning SystemsOverview of the Broadest & Deepest Portfolio of Precision Motion and Automation Technologies from Piezo to Air Bearings and Linear Motors
- Products: Overview, New, Finder, ShopFind Precision Positioning Solutions Quickly - Product Finder | PI USAWith thousands of standard products and customization available, PI has the motion control positioning product solution for your application.
- Products OverviewProducts OverviewOverview of the Broadest & Deepest Portfolio of Precision Motion and Automation Technologies from Piezo to Air Bearings and Linear Motors
- New ProductsNew Motion Control & Precision Positioning Products | PI USALearn about the latest innovations in motion control and nanopositioning components and systems.
- Product FinderUse the PI Product Finder - it's fast and easy!Select the product type specified by the axes of motion required. Selection of more criteria expands or shortens the list of results. Select more than one filter at at time, for example, to find positioning stages designed for higher load capacity, too.
- ► Shop► ShopShop for select PI products online
- Products Overview
- Air Bearings & Ultra High Precision StagesAir Bearing Stages | Motorized | Linear | RotaryAir bearings provide advantages over mechanical bearings when vibration-free motion is required, highly constant velocity control is crucial, and when angular repeatability and geometric performance must be optimal. Air bearing stages (linear, rotary, and spherical) replace mechanical contact by a thin air film, avoiding wear, friction, vibration, and hysteresis effects.
- Miniature Positioning StagesMiniature Positioning Stages | Supplier | ManufacturerCompact positioning stages are crucial for the miniaturization process in cutting-edge research and industrial applications, for test & measurement, optical and opto-mechanical alignment, and component assembly. PI provides the largest portfolio of miniature stages, including high-speed linear motor stages, economical stepper motor units, and ultra-compact piezo motor positioners.
- Motorized Stages: Linear, Rotary, XYMotorized Stages | Positioning | ManufacturerPI offers the broadest and deepest range of precision motion technologies for micro and nano precision applications. Our engineers work with our customers to find the best drive and bearing technology for each individual application. Having access to multiple drive and positioning technologies allows an open discussion with a better outcome for the customer.
- Overview - Motorized Linear/Rotary StagesOverview - Motorized Linear/Rotary Stages
- Linear StagesLinear Stages - Precision Positioning Solutions | PI USASeveral types of motorized precision linear translation stages | PI USA
- Fast Linear Motor Stages and ActuatorsOverview: Linear Stage, Linear Motor Driven, Fast Brushless Motor Positioning Stages | PI USABrushless linear motor-driven stages provide high speed, precision and long life.
- Z-Stages (Vertical Motion)Vertical Linear Stages – Precision Motorized Z-Positioners | PI USA
- XY StagesXY Stages – 2-Axis Motorized Precision Positioning Stages | PI USASeveral types of planar XY stages: Direct-driven stages, ball-screw stages and air bearing planar XY stages
- XYZ StagesXYZ Stage - Multi-Axis Precision Motorized Stages
- Rotary Stages / GoniometersPrecision Rotation Stage, High Resolution Rotary Positioners, Rotation Tables, Goniometers, by PI USASeveral types of motorized rotation stages: Direct-driven stages, ball-bearing stages and air bearing stages
- Heavy Duty Stages / Industrial AutomationHigh Speed / Performance Positioning Stages for Automation - Linear Stages | Rotary Stages | PI USAHigh performance motorized stages, designed for heavy duty applications in industrial precison automation.
- Sub-Systems for AutomationSYS > Engineered Motion/Automation Sub-SystemsThe PI group employs over 1,200 people in 15 countries and runs engineering and manufacturing centers on 3 continents. Select from the broadest portfolio of precision motion technologies, including piezoelectric and air bearing systems, with 1,000’s of standard products or have our engineers provide you with a custom solution.
- Overview - Motorized Linear/Rotary Stages
- Linear ActuatorsActuators | Precision | Linear | Actuator SystemA precision linear actuator is a positioning device that provides motion in 1 degree of freedom. PI designs and manufactures a variety of precision linear actuators (pushers) including economical stepper-motor driven actuators, high-speed linear motor types for automation and nanometer precise piezo-motor actuators.
- Gantries / Cartesian RobotsGantry Stages | Gantries | Cartesian RobotA gantry precision positioning stage is sometimes called a linear robot or Cartesian robot. Gantries typically provide motion in 2 or 3 linear degrees of freedom (X-Y and X-Y-Z) and are often used for pick and place applications, 3D printing or laser machining, and welding applications.
- 6-Axis Hexapods / Parallel PositionersHexapod Positioner | Six DOF | Stewart PlatformsHexapod positioners are often referred to as Stewart Platforms. A hexapod is based on a 6-axis (XYZ, Pitch, Roll, Yaw) actuator system arranged in parallel between a top and bottom platform. PI parallel kinematics (PKM) precision positioning systems have many advantages over serial kinematics stages, such as lower inertia, improved dynamics, smaller package size and higher stiffness. In addition hexapods are more flexible than conventional 6 axis positioners.
- 6-Axis Hexapods / Parallel Positioners6-Axis Hexapods / Parallel Positioners
- Control of Hexapod / Stewart Platforms: Hexapod Motion Controllers & Simulation Software6DOF Motion Platforms | Hexapod Controllers & Simulation Software | Stewart Platform | ManufacturerControllers, software and accessories for Hexapod Stewart platforms and parallel kinematic motion systems | PI USA
- 6-Axis Hexapods / Parallel Positioners
- Piezo Flexure Nanopositioning StagesNanometer Precision: Piezo Stages for Nanopositioning, Piezo Nanopositioners, Piezo Flexure Scanning Stages | PI USAPI offers the broadest and deepest portfolio of nanometer precision motion technologies, from piezo-driven nanopositioning and scanning stages to motorized 6-axis hexapod positioning systems.
- Overview - Piezo Flexure StagesOverview - Piezo Flexure Stages
- Linear Piezo Flexure StagesLinear Piezo Stages for Nanopositioning – Flexure-Guided Precision NanoPositioners | PI USALargest selection of frictionless, high performance piezo-stack-driven flexure linear nanopositioning stages | PI USA
- Vertical & Tip/Tilt Piezo StagesPiezo Z-Stage, Piezo Z-Tip-Tilt Platform. Flexure Guided Nanopositioning Stages| PI USALarge selection of Piezo Z-Stages and Tip/Tilt scanners with nanometer precision | PI USA
- Fast Steering Mirrors & Tip/Tilt PlatformsPiezo Steering Mirrors | Active Optics
- Nanofocus Lens ScannersFast Piezo Focus Lens Positioners and Scanners – Piezo Flexure Guided Precision Positioners | PI USALargest Selection of Nano-Focus drives for microscope lenses – flexure-guided precision positioners
- XY Piezo Flexure StagesPiezo Stages | XY | Nanopositioning StagesLargest selection of integrated XY piezo flexure stages with nanometer precision.
- XYZ Piezo Flexure StagesXYZ Piezo Nanopositioning Stages – Flexure Guided 3-Axis Precision Positioners | PI USALargest selection of integrated XYZ piezo flexure stages with nanometer precision.
- 6-Axis Piezo Flexure Stages6-Axis Piezo Nanopositioning Stages – Flexure Guided Precision Positioners | PI USAPiezo-driven fast steering mirrors (FSM) achieve nanoradian resolution and high bandwidth.
- Tutorial - Piezo NanopositioningNanometer Precision: Nanopositioning Basics Tutorial. Piezo Nanopositioners, Scanning Stages, Flexure Guided Positioners | PI USAThere are several ways to achieve nanometer precision motion. The best positioning systems avoid friction all together, in both the drive system (motor) and in the guiding system (bearings). Frictionless bearings also avoid the bearing rumble caused by balls and rollers and provide vibration-free motion with highly constant velocity.
- Overview - Piezo Flexure Stages
- Piezo Motors: Stages & ActuatorsPiezo Motors | Linear Motor Positioners | ManufacturerPiezo Motors are intrinsically vacuum compatible, non-magnetic and self locking at rest, providing long travel compared to traditional piezo mechanisms. The individual drive concepts are optimized for different applications, they differ in their design, size, cost, force & speed and other performance parameters.
- Overview - Piezo Motors (Stages/Actuators)Overview - Piezo Motors (Stages/Actuators)
- Actuators with Piezo MotorsCompact precision linear actuators stages with several types of piezo motor drives – ultrasonic, stick-slip, piezo-walk, piezo-ratchet. | PI USA
- Linear Stages with Piezo MotorsPrecision linear stages with several types of piezo motor drives – ultrasonic, stick-slip, piezo-walk, piezo-ratchet. | PI USA
- XY Stages with Piezo MotorsXY piezo motor linear stages with several types of precision piezo motor drives – ultrasonic, stick-slip, piezo-walk | PI USA
- XY Piezo Flexure StagesXY Piezo Flexure StagesHigh-precision 2-axis nanopositioning systems integrate PICMA® piezo actuators for maximum reliability. Repeatable, drift-free positioning with optimal stability is possible by the use of high-quality nanometrology sensors.
- Rotary Stages with Piezo MotorsRotary piezo motor stages with several types of precision piezo motors– ultrasonic, stick-slip (inertia), | PI USA
- Tutorial - Piezo Motion ControlWhy All Piezo Motors are NOT Created Equal: The piezoelectric effect for precision motion control - PI Physik Instrumente.The demand for higher speed and/or precision in fields such as bio-nanotechnology, semiconductors, metrology, data comm, and photonics keep pushing manufacturers to come up with innovative drive technologies.
- Overview - Piezo Motors (Stages/Actuators)
- Piezo Transducers & ActuatorsPiezo Actuator | Piezo Transducer | ManufacturerPiezoelectric translators (transducers) are precision ceramic actuators which convert electrical energy directly into linear motion with high speed, force and virtually unlimited resolution. These actuators are used in every modern high tech field from semiconductor test & inspection to super-resolution microscopy, bio-nanotechnology and astronomy/aerospace technology.
- Piezo Actuators & Transducers: Stacks, Chips, Benders, Tubes, Spheres, Shear…Piezo Actuators & Transducers: Stacks, Chips, Benders, Tubes, Spheres, Shear…
- Value-Added Piezo Transducers & Piezo AssembliesValue Added Piezo Assemblies: Transducers, Actuators, Sensors, Manufactured by PI CeramicDeveloping and manufacturing piezo ceramic materials and components are complex processes. PI Ceramic - PI’s piezo material design and manufacturing facility - boasts several decades of experience as well as the right tools for rapid prototyping of custom engineered piezo components and assemblies. From the formulation of advanced piezo materials to the processing steps such as cutting, milling, grinding, and the precision assembly, every stage is controlled by our engineers and product specialists.
- Piezo Ceramic ComponentsPiezo Ceramic Components
- Piezo Actuators & Transducers: Stacks, Chips, Benders, Tubes, Spheres, Shear…
- Microscopy, Bio-Imaging, Life SciencesHigh Precision Microscope Stages, Piezo Lens Scanners, Tools for Bio-Imaging | PI-USAPiezo nano-positioning stages are essential tools for high-resolution microscopy, such as Super Resolution Microscopy or AFM. Their sub-atomic resolution and extremely fast response allow researchers to create higher-quality images faster. PI provides a large variety of fast Z-Stages and collar piezo objective positioners for 3D imaging (Z-stack acquisition), deconvolution, and fast focusing applications.
- Stages for Microscopy & Bio-ImagingStages for Microscopy & Bio-Imaging
- Applications: Life Sciences / MedicalPrecision motion control for medical engineering and life sciences applications | PI USA
- Stages for Microscopy & Bio-Imaging
- Photonics Alignment SolutionsActive Photonics Alignment | Optics Alignment | SolutionsPI provides a variety of innovative fiber alignment systems from motorized fiber positioners to automated optic and photonic alignment such as used in telecommunication, data commumication and for packaging / automation. In addition to fiber-based applications, fast steering systems for free-space-optical communication are also available. Products range from motorized 6D micromotion alignment systems for industrial photonics automation, through ultra-fast piezoelectric scanning & alignment modules to modular devices with manual control for laboratory test setups. All motorized systems come with extensive software for easy setup and integration.
- Vacuum Positioning Stages & ActuatorsVacuum / UHV Compatible Stages - Linear & Rotary Positioners for Vacuum, Wide Temperature Ranges | PI USAPI miCos has extensive experience in the design and manufacturing of vacuum and high vacuum compatible precision optomechanical positioning equipment for low temperature and wide temperature ranges. We provide translation stages, vertical linear stages, rotation stages, XY stages and complex multi-axis positioning systems in vacuum spec.
- VacuumProduct Series with Vacuum-Ready ItemsPI offers specific catalogue items for selected product series that are already suitable for high vacuum (HV) or ultra-high vacuum (UHV).
- Vacuum
- Controllers, Drivers, Motion SoftwareMotion Controllers, Piezo Drivers-High Voltage Amplifiers, and Motion Software Overview | PI USA
- Overview - Controllers & Motion SoftwareOverview - Controllers & Motion Software
- Piezo Controller, Driver, Nanopositioning Controller, High-Voltage Amplifier, Piezo Power Supply by PI USAPiezo Drivers | Piezo Motion Controllers | ManufacturerA piezo controller or driver is used to control the motion of a piezo positioning device. There are open and closed loop controllers. Open-loop controllers are often referred to as piezo driver or even piezo power supply. Closed-loop controllers are divided in two basic types: analog-servo and digital servo controllers.
- Controllers/Drivers for Motorized StagesMotion Controller | Drivers | Positioning SystemsPI provides a large variety of hardware & software solutions for high precision motion control. Our portfolio spans from integrated compact single axis servo controllers / drivers, such as popular Mercury-class motion controllers, to complex multi-axis systems for parallel-kinematics positioners, such as hexapods.
- ACS Motion ControlACS Motion Control for Industrial AutomationWe recommend the controllers of our partner, ACS Motion Control especially for automation with industrial standards. Ask us about your integrated solution!
- Software - Motion Control SoftwareMotion Control Software | Software Tools | Positioning SolutionsFor LabView, C++, VB, Matlab, Image Acquisitiong Packages, NI DAC Cards, ..... PI provides high-level, robust, easy-to-use software tools for fast, seamless integration of motion systems into application control software.
- Overview - Controllers & Motion Software
- Capacitive SensorsNanometer Resolution: Capacitance Sensors for Nano-Measuring, Nano-Metrology | PIA capacitive sensor is a proximity sensor that detects nearby objects by their effect on the electrical field created by the sensor.
- Accessories: Plates, Brackets, CablesAdapters and Cables for PI Precision Motion ComponentsStandardization is common with adapter plates and brackets, but we can create a custom accessory to fit your application system. PI products ship with the required cables. Customization is always an option.
- Products: Overview, New, Finder, Shop
- Tech BlogPI Blog / Tech Articles on Advancements in Precision Motion Control, Automation and Piezo Technology | PI USAPI’s tech blog offers 50 years of insight into innovative applications of precision motion control, nanopositioning, and micropositioning in industry, science, and research. We hope the PI blog is an enjoyable and informative resource, and a starting-point for innovation across disciplines.
- Resources
PI – Resources – Papers, Videos, ISO9001, Service, DownloadsFind Tech Articles, Videos, Papers, Brochures, Software Information, ISO9001 Certificates and more.- Ask an Engineer (direct email request)Ask an Engineer (direct email request)
- User Manuals, Software, WhitepapersUser Manuals, Software, WhitepapersFind product documentation & software, catalogs & brochures, whitepapers & success stories.
- Catalogs & BrochuresDownload Catalogs on Precision Motion Control and Nanopositioning ProductsFind brochures and catalogs for download.
- ISO 90001 CertificatesISO 90001 CertificatesView PI's active ISO certificate
- Metric Tolerances & Thread PitchMetric Tolerances & Thread PitchView metric tolerances and thread pitch classifications
- Motion Control SoftwareMotion Control SoftwarePI provides high-level, robust, easy-to-use motion control software tools for fast, seamless integration of motion systems into application control software. Supported programming languages and applications include LabView, C++, VB, Matlab, Image Acquisitioning Packages, NI DAC Cards, ...
- News & EventsNews & EventsFind PI press releases, enews, and tradeshow exhibit schedule where you can get free advice from a PI Engineer.
- SeminarsFree Seminars on Precision Motion Control / Automation – Motorized and Piezo-Based Solutions | PI USA
- ServicePI – Global Customer Services
- On-Site ServicesOn-Site ServicesThe PI Global Services Division (GSD) is a team of PI skilled after-sales support engineers located around the world, dedicated to providing world class customer support.
- Extended WarrantyExtended Warranty
- Ask an EngineerAsk an EngineerQuickly receive an answer to your question by email or phone from a local PI sales engineer.
- Request ServiceRequest ServiceQuickly receive an answer to your question by email or phone from a local PI sales engineer.
- DownloadsDownloadsFind interesting downloads: Product documentations, brochures, catalogs, certificates, success stories, whitepaper and PI Update Finder.
- Expert Consultancy from PIExpert Consultancy from PIIf our customers need to solve a complex problem, they often require individual advice. We are happy to come and advise you on site.
- On-Site Services
- Tech BlogTech BlogPI’s tech blog offers over 40 years of insight into innovative applications of precision motion control, nanopositioning, and micropositioning in industry, science, and research. We hope the PI blog is an enjoyable and informative resource, and a starting-point for innovation across disciplines.
- Technical Papers / WhitepapersTechnotes & Whitepapers / Application Articles: Piezo / Micro- / Nanopositioning Motion Control: Technical Research PaperPI precision motion and positioning solutions have helped customers in many industrial fields and research laboratories to achieve their goals faster. Feel free to download the papers below.
- Videos & AnimationsVideos on Motion Control and Positioning Technologies | PI USAWatch videos, animations and practical applications of PI products, systems, components
- WebinarsWebinarsWebinar topics include piezo mechanisms, adaptive machines, automation manufacturing advancements, photonics assembly & packing concepts.
- Apps/Tech
Technologies and Applications for Precision Motion Components and Sub-Systems | PI USAPI products are often used at the cutting edge of technology. They solve critical motion problems in lithography, microscopy, astronomy, laser technology, photonics and semiconductor manufacturing on locations around the world and in places as remote as the Science Lab on the Mars Rover.- News/Events
PI - Webinars On-Demand, Company Announcements, New Products for Precision Motion ControlStay up-to-date with the latest PI news, view our webinars on-demand, see product demos or virtual tradeshows, or connect with a PI engineer.- News & EventsNews & EventsStay up to date with the latest PI news, or plan on talking to a PI engineer at a tradeshow.
- Virtual TradeshowsVirtual TradeshowsWith conferences and tradeshows on hold for now, use our virtual tradeshow booth to learn more about how PI solutions enable researchers and technology leaders across many industries to innovate and stay ahead.
- Product DemosProduct DemosCheck out PI's product demos that you would have seen at a conference or tradeshow.
- WebinarsMotion Control On-Demand WebinarsWebinar topics include piezo mechanisms, adaptive machines, automation manufacturing advancements, photonics assembly & packing concepts
- About
About PI USA: Custom design & service / export controlled applications & ITAR RegisteredPI (Physik Instrumente) provides the broadest and deepest portfolio of precision motion technologies in the world. PI USA complies with the US laws for export controlled technologies.- AboutAbout PI USA / Custom design & service / export controlled applications & ITAR RegisteredPI (Physik Instrumente) provides the broadest and deepest portfolio of precision motion technologies in the world. PI USA complies with the US laws for export controlled technologies.
- Online Contact FormOnline Contact FormLooking for product information, datasheets, CAD files? Want to have a brainstorming consultation? Need an RMA? Have questions about your order? Request a catalog? Contact us! We're here to help you.
- Directions to PI USA OfficesDirections to PI (Physik Instrumente) USA Offices – Global Leader in Precision Motion Control Solutions
- Ask an Engineer (direct email)Ask an Engineer (direct email)Talk to our engineers first. They have access to in-depth knowledge and test data on diverse driving and guiding technologies, spanning from electromagnetic to piezoceramic and from mag-lev to air bearings. They also have experience selecting the right technology for each individual application. Often an adaptation of existing technologies/products will suffice to solve a problem. However, experience along with detailed knowledge and PI’s significant R&D investment in new technologies enables our engineers to take unique approaches.
- Request a SeminarRequest a Seminar
- News & EventsNews & Events
- CareersCareers at PI - Join the Global Leader in Precision Motion & Positioning TechnologiesPI offers sound training in technical and business careers with a future. Pupils, students, graduates and professionals can get involved at PI and will be supported by us in their professional and personal further development.
- ITAR / Export Controlled ApplicationsPI-USA: ITAR registered, motion control for defense applications, security, COTS, custom US based design, by PI USA
- Test & Metrology / Manufacturing Equipment / CleanroomsLearn what Nano-Metrology Equipment is Used to Test High-Performance Motion & Positioning Systems
- Test & Metrology / Manufacturing Equipment / Cleanrooms OverviewTest & Metrology / Manufacturing Equipment / Cleanrooms Overview
- Manufacturing in Cleanrooms at PIManufacturing in Cleanrooms at PIPI has the capability to manufacture and qualify products under cleanroom conditions, which is extended and improved continually according to market needs.
- Fractal Manufacturing Structure at PIFractal Manufacturing Structure at PIPI manufactures in autonomous organization fractals. Each unit is responsible for its own product line, has all the necessary skills and production equipment.
- Test & Metrology / Manufacturing Equipment / Cleanrooms Overview
- Watch PI Product Videos on YouTubeWatch PI Product Videos on YouTubeUse PI product videos as a resource for how you can apply our precision motion control technology to your application. Then, talk to a PI Engineer about how to make it happen.
- Connect with PI on LinkedInConnect with PI on LinkedInConnect with PI USA on LinkedIn
- Follow PI on TwitterFollow PI on TwitterFollow PI on Twitter
- PI WorldwidePI WorldwideThe PI Group represented by subsidiaries and dealers all over the world. Check here to find your local contact!
- Ask an Engineer
Get Help from a PI Engineer*Save Time & Headaches – Get Free Advice from a PI Engineer* Tap into our engineers’ collective knowledge base – not only is it free, but it also saves hours of your valuable time while preventing plenty of headaches in the future.- Contact
ContactLooking for product information, datasheets, CAD files? Want to have a brainstorming consultation? Need an RMA? Have questions about your order? Request a catalog? Contact us! We're here to help you.- Shop
ShopShop for select PI Motion Control, Positioning and Piezo Solutions products online- Buy Motion Control, Positioning and Piezo Solutions OnlineBuy Motion Control, Positioning and Piezo Solutions OnlineShop for select PI Motion Control, Positioning and Piezo Solutions products online (select products)
- 0Quote list
- Search
Providing precision positioning equipment for a vacuum environment follows clearly defined conditions. First, contamination of the vacuum chamber with particles through abrasion or outgassing but also through excessive heat input must be avoided. In addition, the installation space is usually limited. PI has many years of experience in vacuum technology and applications as well as a high vertical range of manufacturing. Therefore, PI is able to offer standard and customized products that are precisely tailored to the requirements of the vacuum application, e.g. by appropriate drive components, material selection, design, and accessories as well as suitable manufacturing processes and quality control.
Standard products to 10-9 hPa, customized solutions to 10-12 hPaPosition resolution to less than 1 nm with piezo direct drives, less than 1 μm with motorized stagesTravel range of a few 10 μm up to 100 mm, optionally even moreLoad capacity up to several 100 kgOperation in magnetic fields and EUVPositioning Solutions for Vacuum Environments
PI offers various motion technologies that are suitable for vacuum applications: This includes piezo actuators, which can also work in strong magnetic fields and cryogenic environment, piezo systems with travel ranges of less than 1.5 mm and subnanometer precision, piezo motors in different designs with respect to force, dynamics, and travel range, motorized positioners with specially designed DC or stepper motors that allow larger travel ranges as well as parallel kinematic hexapods for positioning in six degrees of freedom.
PI offers a wide range of products that have been developed on the basis of >> piezo actuators. Piezo actuators do not require lubricants or cause abrasion. Their motion is based on the >> piezo effect, and is therefore wear free. As the piezo effect is based on electric fields, piezo actuators neither generate nor are they affected by magnetic fields. The piezo effect exists even at lowest temperatures close to 0 Kelvin. In addition, piezo ceramics are insensitive to high-energy radiation. The >> PICMA® all-ceramic isolated actuators do not require polymer insulation and provide the optimum conditions for use in ultrahigh vacuum: no outgassing and high bakeout temperatures of up to 150 °C.
The high stiffness of piezo actuators enables high force generation and dynamics. Their rapid response time in the microsecond range is a result of their high resonant frequency of several hundred kilohertz. The travel ranges of piezo actuators are typically in between a few 10 to a few 100 μm for linear actuators. Bending actuators can achieve a few millimeters. Piezo actuators reach subnanometer resolution.
Depending on the configuration and control, piezoceramic actuators can be used for translational, rational motion (tip/tilt), or as motors. The choice of the drive principle depends on the required travel ranges, forces, resolution, and velocities of the respective application. Next to the drive type, the selection of suitable materials and additional components is decisive for the use of piezo-based positioning systems in a vacuum. For this reason, vacuum-suitable housings, position sensors, and guide systems such as >> capacitive sensors or >> flexure guides are selected. In addition, piezo motors also do not require lubricants or greases for operation.
Regardless of the drive principle, all >> piezomotors can be used in a vacuum and are the drive of choice, especially when travel ranges in the millimeter range are required.
PI offers specific vacuum-ready standard products for selected product series that are already suitable for high vacuum (HV) or ultrahigh vacuum (UHV). Furthermore, most PI products can be modified on request for use in a vacuum. The products provided by PI achieve atmospheric pressure down to 10-9 hPa. In some cases, 10-10 hPa can be reached.
Table 1 shows the different measures taken to achieve the corresponding vacuum class.Vacuum class Motor Measuring system Material Cable and connectors Guides and spindles Venting Bakeout temperature to 10-6 hPa Greased motor Standard measuring system Anodized aluminum components; brass allowed; plastics allowed 2 m PTFE cable with standard connector Guides and spindles with vacuum grease Partly with cannulated screws Bakeout temperature max. 80°C to 10-7 hPa HV Motor HV measuring system Aluminum, blank; brass allowed; selected plastics 2 m PI or PTFE cable with UHV connector Guide and spindle made of stainless steel with vacuum grease Cannulated screws Bakeout temperature max. 80°C to 10-9 hPa Special UHV motor with temperature sensor UHV measuring system Aluminum, blank; brass not allowed; no plastic except PEEK or polyimide 2 m PI cable with UHV connector Guide and spindle made of stainless steel with vacuum grease Cannulated screws Bakeout temperature max. 120°C with/ 150°C without measuring system Tab. 1: Different measures taken to achieve the corresponding vacuum class of motorized positioners.
Hexapod platforms are used for precision positioning and alignment of loads in all six degrees of freedom, which means three linear axes, and three rotational axes. Hexapods have a >> parallel-kinematic structure, i.e., the motion platform is actuated simultaneously by multiple actuators. In a parallel-kinematic hexapod all drives act on a single motion platform, which results in a much more compact design than possible with stacked systems. Hexapods feature a high stiffness; therefore, they can be mounted in any orientation. As only one platform is moved, the overall moved mass is lower if compared with a stacked or nested positioning system, resulting in lower inertia, and therefore higher dynamics, which is the same for all motion axes.
Depending on their design, hexapods can position loads from several kg up to several tons in any spatial orientation, independently of the mounting orientation and with submicrometer precision. Designed properly, hexapods are suitable for use in vacuum and can be adapted to different vacuum classes using electric motors or piezoelectric drives and vacuum-suitable sensor technology.
To determine the required vacuum class, it is necessary to know the application as well as possible. For example, EUV lithography, the production of microelectronic circuits, or material analysis using SEM (scanning electron microscopy) place different demands on the pressure range, but also on the permissible residual materials in the vacuum chamber. Therefore, the outgassing rate is another relevant specification. Often the partial pressure of HCs (hydrocarbons) is decisive. Because it determines the pressure in the system (together with the capacity of the vacuum pump), outgassing prohibits fast achievement of low pressure values. In addition, the outgassing compounds may deposit on surfaces of optical elements or other sensitive devices and can obscure or damage them. Therefore, the residual gas must contain very little or no HCs and no metals with high vapor pressure such as zinc, lead, or cadmium.
Vacuum is the state of a gas, when in the pressure of the gas in a container and thus the particle count density is lower than outside or if the pressure of the gas is lower than 300 mbar, i.e. smaller than the lowest one on the atmospheric pressure on the Earth's surface {DIN 28400}. It is measured in either [hPa], [mbar] or [Torr]. Different levels of vacuum classes are defined: rough, fine, high, ultrahigh, and extremely-high (shown in Tab. 2). PI offers standard products for selected product series that are already suitable for HV or UHV conditions. Furthermore, most PI products can be modified on request for use in a vacuum. The products provided by PI achieve a pressure down to 10-9 hPa. In some cases, 10-12 hPa can be reached.
Vacuum class Abbr. hPa mbar Torr Rough vacuum RV 300 to 1 300 to 1 225 to 0.75 Fine vacuum FV <1 to 10-3 <1 to 10-3 <0.75 to 7.5 × 10-4 High vacuum HV <10-3 to 10-7 <10-3 to 10-7 <7.5 × 10-4 to 7.5 × 10-8 Ultrahigh vacuum UHV <10-7 to 10-12 <10-7 to 10-12 <7.5 × 10-8 to 7.5 × 10-13 Extremly-high vacuum XHV <10-12 <10-12 <7.5 × 10-13 Tab. 2: Definition of vacuum classes
How to Overcome Challenges of Vacuum Applications
Because outgassing is a challenge for creating and maintaining clean high-vacuum environments, the right choice of materials and treatments is compulsory in the design and production of vacuum systems. To manufacture products for high (HV) or ultrahigh (UHV) vacuum the following has to be considered: material selection, design, manufacturing and commissioning processes.
The material may not outgas and must be resistant to heat in order to overcome the bakeout temperatures necessary for higher vacuum classes. However, the required precision and high position resolution as well as flatness must be maintained.
For example, common electrical and electronic equipment contains components that either do not suit vacuum applications or only to limited extent. These comprise cables, motors, scaling systems, connectors or limit switches. PI implements specific product features for all these components to strongly reduce outgassing from these components and creating a clean vacuum environment.Therefore, the materials used for vacuum positioning systems are aluminum alloys, stainless steels, titanium, or bronze. Surface treatment is adapted to the vacuum class, for example, the surfaces of the higher vacuum classes are not coated but blanc aluminum or electro polish. For use in HV and UHV, special vacuum lubricants are used. On request, the lubricant may be defined when placing the order. Vacuum cable insulation is made of PTFE or FEP (Teflon), and also of polyimide (Kapton) or PEEK. The use of adhesives is reduced as far as possible.
Substituting standard materials with vacuum-suitable materials, is a strict requirement of vacuum stage design. Another requirement is the reduction and minimization of the surface of the system.
In addition, it is important to avoid air inclusions since these act like virtual leaks in a vacuum.
The gas in this trapped volume cannot be pumped out easily due to only narrow paths connecting to the vacuum chamber. This delays reaching the required vacuum level.
Trapped volumes are usually caused by unvented or poorly vented blind tapped holes. These are either at the tip of a screw or under the rim of the screw head. Furthermore, holes that are covered either when mounting the positioner on a base plate or fixing a sample on the positioner, often cause virtual leaks. When virtual leaks are caused by screws, the use of vented screws, for example, is recommended.The conditions and handling regulations for vacuum positioning systems are just as important as the design principles. Vacuum stages are mounted under cleanroom conditions. All components are cleaned in an ultrasonic bath. They are shipped in a packaging free from particles. Before a vacuum positioner is assembled, all pure metal parts undergo a cleaning process in an ultrasonic bath. Electrical and electronic units are wipe-cleaned. Standard, lubricated components such as bearings and guides are degreased, cleaned, and lubricated with special vacuum grease. Ultrasonic-cleaned components are dried in a climate chamber.
The assembly of a stage is carried out in a >> cleanroom or in a flow box. After assembling, the stage must pass a performance test in a clean environment. Vacuum tests are performed for each type of stage and when vacuum-critical changes are made to the product. After assembling, the system is packed in vacuum-sealed bags protected against dirt, air, and humidity: First, the stage undergoes a baking process in a climate chamber. After packing and sealing in an inner vacuum bag, the stage is then put into a second, outer vacuum bag that is then vacuum sealed completely.
Vacuum-suitable products undergo standard testing at PI. Additionally, customized tests can be ordered for individual vacuum applications. PI has several vacuum chambers with different volumes for bakeout and residual gas analysis.
For testing single components or for testing small stages, a chamber is available with a volume of approximately 10 l. The small vacuum chamber is equipped with a pump stand consisting of a 400 l/s (N2) turbomolecular pump and a pressure sensor for continuous pressure sensing, which means that pressures below 10-10 hPa can be reached. A heating facility allows bakeout temperatures up to 200 °C.A large chamber with a volume of 260 l is designed for large stages up to a length of 800 mm, hexapods, and for multi-axis systems. A pump stand with a 700 l/s (N2) turbomolecular pump and a pressure sensor allow testing down to 10-9 hPa. Bakeout temperatures up to 150 °C are possible with the integrated heating system.
For in-vacuum operation tests on stages flanges of different sizes are available for motor current, linear encoder, limit switches, temperature sensors etc. with various feedthroughs. If interferometric measurements are required or a visual observation of processes is necessary, both chambers can be equipped with inspection windows. A quadrupole mass spectrometer is available for real-time RGA (residual gas analysis) between 1 amu to 200 amu, which can be attached to both chambers.
PI classifies and verifies the vacuum products by vacuum pressure measurements and RGA (residual gas analysis) in the vacuum chambers. Depending on which vacuum level needs to be reached, the chambers and stages are baked out accordingly.
- Resources