Sunday, March 31, 2019

New Epoxy Compounds Give Researchers and OEM's Design Freedom in Specifying Vacuum Feedthroughs

OEM feedthrough
OEMs can no get a feedthrough to fit their design criteria.
Scientists and researchers are constantly challenged to come up with better ways to read data in a vacuum environment. Traditional ceramic and glass-to-metal vacuum feedthroughs do not offer design flexibility. Unique control and data signals must pass through the wall. In addition to passing electrical power and control signals, fiber optic cables and pneumatic tubing may be included. Always changing variables, such as the number and types of connectors, unique geometries, and limited available space, make finding an off-the-shelf feedthrough difficult. This has traditionally forced designers to compromise and specify a feedthrough with some, but not all, of the desired specifications. 

epoxy feedthrough
Clear epoxy feedthrough with ribbon connector.
This reality has led to significant development gains in custom epoxy feedthrough. Epoxy feedthroughs overcome design constraints. New epoxy properties rivaling ceramic and glass performance have been developed. High performance, clear epoxy potting opens the door for researchers to specify the exact number and type of wires, optical fiber cables, or any other insert that they require. Epoxy feedthrough manufacturers can provide a virtually limitless variety of wires, cables, or tubes along with the added benefit of fast prototyping and small production runs — perfect for the research and manufacturing community. 

Flanged feedthrough
Flanged feedthrough with epoxy potted fiber optic cable.
With the development of custom epoxy feedthroughs medical device companies, analyzer manufacturers, laboratories, aerospace companies and other R&D facilities can design their equipment based on optimum size, cost and performance, and not be forced to compromise by the limitations of ceramic and glass-to-metal feedthrough. Because of the constant pressure on "better, faster, smaller" vacuum equipment researchers and OEM designers, it's clear that epoxy feedthroughs provide flexibility and options for more efficient and creative design.

For information on epoxy vacuum feedthroughs, contact: 

(510) 274-1990

Tuesday, March 26, 2019

Feedthroughs Used for Penetration of Vacuum and Pressure Vessels

Many types of OEM equipment, including medical, analytical, semiconductor, aerospace and laboratory test equipment, require a leak-proof penetration into a vacuum or pressure chamber. The device that accommodates this penetration is referred to as a feedthrough (sometimes spelled "feedthru"). For the most part feedthroughs allow electrical currents or voltages into the vacuum or pressurized area. There are also many other non-electrical requirements for pressure/vacuum vessel penetration. Some examples of non-electrical penetrations are fiber-optic, fluid tubing bundles, and process control sensors such as thermocouples.

Multi-pin Threaded or Flanged FeedthroughsMulti-pin Threaded or Flanged Feedthroughs

Multi-pin feedthroughs have circular flanged or threaded connectors for moderate pin density. They are typically offered with differing numbers of pins (often, 3, 5 or 7) and rated to 3.5 amps and 500 volts per pin. There are both single-ended and double-ended versions which offer a connector for the air side or both air and vacuum side connectors respectively.

Thermocouple FeedthroughsThermocouple Feedthroughs

A thermocouple feedthrough is an electrical vacuum feedthrough commonly used for systems involved in temperature measurement. The thermocouple feedthrough itself doesn’t measure temperature, but is used to conduct the voltage signal from the vacuum to an external device. These are suitable for use in ultra-high vacuum applications.

High Power FeedthroughsHigh Power Feedthroughs

High power electrical feedthroughs transmit high current and/or high voltage into a vacuum system. Variations of power electrical feedthroughs offer a range of current and voltage.

Epoxy Potted Feedthroughs
Epoxy Potted Feedthroughs

Epoxy vacuum feedthroughs offer the best application flexibility, they are cost competitive, and they have a high vacuum performance for today’s fast moving markets. Clear epoxy feedthroughs allow for the visual inspection of your components. They are board mountable with high vacuum performance and very competitive pricing compared to ceramic and metal seals.

Fiber Optic FeedthroughsFiber Optic Feedthroughs

Fiber Optic Feedthroughs provide the interface between fiber optics and UHV technology. They allow fiber optic cables are designed for vacuum applications requiring fiber optic connections from inside a vacuum system to external equipment.

Fluid FeedthroughsFluid Feedthroughs

Also referred to as fluid feedthroughs, they are designed for the transmission of gases or coolants into high and ultrahigh vacuum environments.  Generally constructed from 300 series stainless steel, they are available in single or multi-tube configurations.

Many accessories are available to be used in conjunction with the wide variety of vacuum feedthroughs. These included vacuum connectors, connectors, insulated wire, cable assemblies, insulators, and spacers, just to name a few.

Specialized feedthroughs may be needed if your application includes cryogenic or very low temperatures, high temperatures, aggressive chemicals, or high pressure. Contact an experienced manufacturer who specializes in vacuum feedthroughs to discuss which feedthrough will best meet your needs. A company worth their salt should be able to discern which would be the best fit with minimal hassle.

Friday, March 8, 2019

Twin Type-C Thermocouple, High Temperature, High Vacuum Feedthrough

Twin Type-C Thermocouple FeedthroughBACKGROUND

An application was presented to BCE in the semiconductor equipment industry for a high temperature, high vacuum thermocouple (TC). There was space limitation with a requirement for a multi-point TC to sense a very small insertion dimension. The TC probe area must be able to bend to allow the sensor tip to penetrate the temperature sensing zone. The BCE engineers and technicians were ready for the challenge with their experience in ceramic-to-metal sealing and high temp sensors.

  • Twin Type-C Thermocouple Vacuum Feedthrough needed to satisfy the following criteria:
  • <1425°C continuous operating temperature in probe area
  • Two independent type “C” thermocouple probes
  • KF16 Flange
  • Vacuum rating: 10 9̄ ATM-CC/Sec
  • Feedthrough Seal Temp: -25°C to 300°C
  • Probe section needs to be bendable and vacuum compatible with SEMI standard

BCE designed an effective High Temperature Vacuum TC that was delivered for prototyping and customer testing. The application requirement was met and the function was sound. All tests performed prior to shipping were completed at BCE. A standard operating procedure (SOP) was finished and the part is production ready.

More information on this BCE product can be found at this link.