Choosing the Right Feedthrough Connection for Your Needs
In vacuum systems, selecting the appropriate feedthrough is crucial to achieving reliable connections and maintaining vacuum integrity while transferring power, fluids, gasses, or motion. Each of these transfers requires specialized vacuum feedthroughs, which can be daunting to select with all the available options. This guide will help you understand the various types of feedthroughs available and select the best option based on your vacuum application’s unique requirements.
Table of Contents
Electrical Feedthroughs for High Power Transfer
Electrical feedthroughs are essential for transferring electrical signals and power into a vacuum environment. ANCORP manufactures low-voltage, high-current electrical power power feedthroughs typically under 50 volts with currents reaching the hundred to thousand amperage range. This pairing of power and voltage creates a feedthrough ideal for deposition sources, sputtering targets, plasma generation, substrate heating, and other equipment in semiconductor manufacturing, thin film deposition, and research analysis.
ANCORP’s high power feedthrough range offers solutions for those needing low-voltage and high-current feedthroughs in high vacuum environments. The range includes two options to meet differing current requirements: 400-amp and 1000-amp. They are designed to mount to standard 1” diameter holes via the baseplate and are made from a one-piece construction eliminating potential joint leak paths.
Both feedthroughs are constructed from oxygen-free copper and brass with high-quality PTFE insulators. The high-current, 1000-amp, electrical connector has a water line connector designed to accept ¼ inch poly flow tubing.
Other electrical feedthrough types are available to provide solutions for varying electric needs within vacuum systems such as thermocouple feedthroughs, multipin feedthroughs, coaxial feedthroughs, and RF feedthroughs for example. Thermocouple feedthroughs, though equipped to transfer electrical signals, are specifically used for temperature measurement and designed to maintain the integrity of thermocouple wires for precise temperature readings. Multipin feedthroughs allow for multiple electrical connections through a single port, ideal for complex system setups. Coaxial feedthroughs, on the other hand, are single-pinned and transfer signals shielded from electrostatic interference with inner and outer conductors. Finally, RF feedthroughs transmit radio frequency power in applications where current induction must be reduced such as induction heating, non-magnetic interference, or plasma generation is required. If any of these further specialized electrical feedthroughs are required for your application, ANCORP can supply you with what you need. Please include the details of your request in a contact form or live chat.
Electrical Feedthroughs
- Voltage: Up to 50 volts (low voltage)
- Current: Options include 400-amp and 1000-amp high-current feedthroughs
- Materials: oxygen-free copper (OFC), brass, PTFE insulator
- Connection: 1-inch baseplate
Fluid and Gas Feedthroughs for Cryogenic and Non-Cryogenic Substances
Non-cryogenic and Gas feedthroughs
Non-cryogenic feedthroughs transmit standard fluids and gasses that do not require low-temperature conditions. The versatility for non-cryogenic feedthroughs is vast, available with single or double tubes and various fittings to suit different environmental conditions.
Fluid and gas feedthroughs enable the transmission of fluids, cooling agents, and gases into vacuum chambers. Designed to support HV and UHV environments, these feedthroughs are often specified based on the physical properties of the fluid they carry and, therefore, are split into two categories: non-cryogenic and cryogenic.
Bodies of non-cryogenic feedthroughs feature a 304 stainless steel construction with alternative tube connections such as VCR® and Swagelok® made from 316 stainless steel. The maximum temperature for these feedthroughs is dependent on the selected sealing method. Noncryogenic feedthroughs with ConFlat flanged ends can reach maximum temperatures of 450* C while ISO and baseplate connections reach 150* (200* intermittently).
Non-cryogenic and gas feedthrough quick reference:
- For transfer of fluids that don’t require low-temperature
- Material: 304 stainless steel main body, 316 stainless steel for tube connections
- Connections: CF flanged feedthroughs (UHV 1×10-13 Torr) and ISO-QF (KF) and baseplate feedthroughs (HV 1×10-8 Torr)
Cryogenic Fluid Feedthroughs
Cryogenic feedthroughs are engineered to transfer ultra-cold fluids, such as liquid nitrogen or helium, into vacuum chambers. These feedthroughs are vital for applications requiring stable, low temperatures for the proper operation of superconducting magnets, cryopumps, and other low-temperature research experiments.
ANCORP cryogenic feedthroughs maintain thermal insulation while maintaining vacuum integrity. This is possible due to the special design of an insulating shield to prevent heat transfer in cryogenic feedthroughs. Other than this insulating shield, the construction of noncryogenic and cryogenic feedthroughs are similar with 304 stainless steel flanges and tubings, with alternative fitting connections such as VCR® and Swagelok® being made from 316 stainless steel.
Cryogenic feedthrough quick reference:
- For transfer of low-temperature fluids
- Material: 304 stainless steel main body, 316 stainless steel for tube connections
- Connections:
- ConFlat (CF) flanges rated for UHV at 1×10-13 Torr)
- ISO-QF (KF) and baseplate feedthroughs (HV 1×10-8 Torr)
Rotary Motion Feedthroughs for Precision Torque Transfer
Rotary motion feedthroughs are engineered to transfer rotational motion into vacuum environments, essential for applications like sample handling, beam steering, and target manipulation. These feedthroughs come in a variety of options with elastomer-sealed and ferro-sealed designs readily available, each suited for different RPM and torque requirements.
Elastomer-sealed Rotary Motion Feedthroughs
Elastomer-sealed feedthroughs are designed for applications with low RPM and quick service needs. Their construction includes a double O-ring seal system ensuring a durable seal and extended service life along with a shaft supported by two ball bearings for extremely low-friction rotation. These feedthroughs are particularly suited for environments involving abrasive or hazardous substances due to its attunement for high vacuum environments and ease of service access.
Thanks to special design considerations from ANCORP engineers, the elastomer-sealed feedthrough O-ring may be regreased or serviced in seconds by removing, replacing, and regreasing all components from the atmosphere side. Additionally, preloaded O-rings seal the shaft, negating any concerns over springs wearing out and further extending service life.
Elastomer-sealed motion feedthrough quick reference:
- For abrasive processes requiring low RPM movement
- Material: Aluminum or 304 stainless steel shafts available
- Connections: Standard 1-inch diameter through-hole
Ferro-sealed Rotary Motion Feedthroughs
Ferro-sealed feedthroughs use ferrofluid O-ring technology to provide superior sealing for high RPM and high torque capacity applications. They are optimized for use in vacuum environments making them suitable for applications in beam steering and rapid sample rotation.
Ferrofluid O-rings are created by the retention of ferrofluid in powerful magnetic fields created by precisely placed, high-strength magnets within the feedthrough body. This hermetically seals the rings to the shaft of the feedthrough and minimizes stray magnetic fields. The roller-bearing spindle design also allows for a smooth rotation and a high number of rotations per minute (up to 5,000 RPMs).
Other than differing torque capabilities, ferro-sealed feedthroughs may be preferrable to elastomer-sealed feedthroughs due to the difference in particulate generation. Due to the elastomer-free construction of a ferrofluid feedthrough, the potential for particle generation from a torqued elastomer O-ring is removed. Additionally, ferrofluid rotary motion feedthroughs tend to have an even longer life when compared with dynamic O-ring seals.
Ferro-sealed motion feedthrough quick reference:
- For high torque and RPM requirements
- Material: Feedthrough shaft and body are 17-4 stainless steel
- Connections
- ConFlat (CF) flanges: 1×10-9 Torr
- ISO-QF (KF) and baseplate feedthroughs: 1×10-8 Torr)
For applications requiring further motion manipulation, such as in the x,y and z plane, ANCORP can supply motion manipulation feedthroughs upon request.
Transition Feedthroughs for Versatile Connections
Transition feedthroughs, sometimes known as baseplate feedthroughs, function as hybrid adapters for various connection needs. They allow users to attach instruments, gas backfill lines, or measurement devices directly to the vacuum chamber’s baseplate.
Flange-Based Transition Feedthroughs
Flange-based transition feedthroughs are designed to adapt baseplate ports in vacuum systems to standard flange configurations, such as ConFlat (CF) or ISO-QF (KF) flanges. These feedthroughs are ideal for connecting vacuum pressure gauges and sensors, gas backfill lines for controlled chamber pressurization, or attaching metal or glass tubing for specialized workflows.
Fitting-Based Transition Feedthroughs
Fitting-based feedthroughs allow direct connections to threaded or quick-disconnect interfaces, offering compatibility with a variety of tools and equipment. These feedthroughs excel in scenarios where non-standard or flexible fittings are required.
Female NPT Fittings: Female NPT feedthroughs provide a secure threaded interface for connecting equipment like gas supply lines or cooling systems.
Quick Disconnects: Quick disconnect feedthroughs offer fast and tool-free connection and disconnection of tubing and equipment. They are particularly useful for applications requiring frequent equipment changes or temporary setups.
Blank Plugs: Blank plug feedthroughs seal off unused bulkhead ports, preventing vacuum leaks and maintaining system integrity. These plugs are simple yet critical components for preserving vacuum performance in unused connections.
Choosing the Right Feedthrough for Your Application
In summary, selecting the ideal vacuum feedthrough depends on your specific operational requirements. For high-power applications, electrical feedthroughs provide reliable low-voltage, high-current connections, with options for water cooling to handle increased amperage. If your system requires the transfer of fluids or gases, fluid and gas feedthroughs offer solutions for both cryogenic and non-cryogenic environments, with multiple flange configurations for seamless system integration.
When precise rotational control is needed, rotary motion feedthroughs deliver smooth performance with elastomer-sealed designs for low RPM applications and ferro-sealed options for high-speed, high-torque applications. Finally, transition feedthroughs offer unmatched versatility, adapting your chamber ports to various flange types or threaded connections.
By carefully evaluating these factors, you can select a feedthrough that not only meets your immediate needs but also enhances the efficiency and reliability of your vacuum system. For detailed specifications and ordering options, explore ANCORP’s comprehensive range of vacuum feedthroughs.