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

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. 

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 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: 

BCE

https://bcemfg.com

(510) 274-1990

Epoxy-based Feedthroughs Provide Design Flexibility, Rapid Prototyping and Cost Savings

Multi-conductor, flanged feedthrough.

The point of view that epoxy-based feedthroughs are inferior to glass-to-metal feedthroughs in terms of sealing and outgassing may have once been true, but modern manufacturing techniques and new epoxy compounds have all but eliminated those concerns. Modern epoxy formulations are more capable of enduring greater mechanical stresses, operating under wider temperature ranges, and sustaining exposure to harsher chemicals than ever before. Today's epoxy-based feedthroughs are excellent choices for even the most challenging feedthrough applications.

Take BCE's proprietary epoxy compound for instance. It seals to 1 X 10E-9 cc/sec of Helium under high vacuum and high pressure. Concerns of outgassing have been erased with the formulation meeting NASA’s ASTM E-595 low-outgassing specification, the industry standard test for measuring outgassing in adhesives and other materials. Developed to screen for low outgassing materials for use in deep space, the test determines the volatile content of material samples placed in a heated vacuum chamber under tightly controlled humidity, temperature, and vacuum conditions.

PCB feedthrough with clear epoxy feedthrough.

Epoxy feedthroughs allow designers and engineers to procure a feedthrough built for the specific task, rather than to accommodate off-the-shelf connectors that are rarely ideal for the specific requirement. Off-the-shelf connectors and feedthroughs impose restrictions on the number and gauge of conductors, as well as the geometry of the device. The use of epoxy-based feedthroughs opens the door for virtually any combination of conductors, tubes, fiber optic cables, sizes and geometries.

It’s important to use the right feedthrough for a given application. Epoxy feedthroughs are not always the right choice, and consultation with an applications expert is always recommended.  But from the viewpoint of engineers and designers, epoxy-based feedthroughs usher in design freedom, prototyping, and cost advantages that once didn't exist. 

Take it All Through the Wall with Epoxy Vacuum Feedthroughs

Glass-to-metal feedthrough

Advances in analytical processes, medical research, and semiconductor processing continually refine the manufacturing capabilities for vacuum systems and components. The need to monitor and control processes is increasing, and getting the required power and control signals into vacuum chambers is increasingly difficult. Devices known as vacuum feedthroughs are used to pass electrical signals, light beams, or pure gases inside a vacuum chamber. Leakage through or around the vacuum feedthrough cannot be tolerated as the vacuum seal is critical to preventing contamination and insuring process integrity.

Glass-to-metal and ceramic-to-metal seals, traditionally the preferred technology, are increasingly problematic - not because of their performance, but because they are constrained by size, geometry, flexibility, and electro-magnetic shielding options. Engineers worked within this reality simply because there were no viable alternatives. Fortunately though, new, advanced sealing epoxy compounds were developed that provided exciting opportunities for vacuum feedthrough manufacturers.

Faster, Less Expensive, More Customizable Feedthroughs

Epoxy vacuum feedthrough.

Today's epoxy vacuum feedthroughs provide the virtually the same performance as their glass and ceramic cousins in low to medium temperatures. Epoxy vacuum feedthroughs offer designers and engineers an excellent alternative in terms of customization and specialization. Shapes, angles and curves are not a problem. Virtually any kind of shielded wire or cable can be used. Custom epoxy vacuum feedthroughs can be quickly provided in very small quantities for prototyping and R&D. Modern epoxy feedthroughs maintain a vacuum up to 10-8 Torr, with temperatures up to 200°C continuous (300°C intermittent), and also meet NASA's outgassing requirement of <1.0% Total Mass Loss (TML). Liquid epoxy's ability to flow and fill spaces thoroughly provides it's advantage, and in most applications, an epoxy feedthrough can be used where a glass-to-metal or ceramic feedthrough is used - the only notable exceptions are in very high temperature applications or where organic compounds are not allowed.

Designers and engineers no longer have to think within the constrained world of glass-to-metal and ceramic-to-metal feedthroughs. Epoxy feedthroughs are a new, exciting player in town, and their lower cost, easy prototyping and more flexible design capability make them a very attractive alternative.

For more information, visit https://BCEmfg.com or call BCE at (510) 274-1990

Custom Electrical, Pneumatic, and Optical Feedthroughs

Equipment manufacturers and scientific researchers are continually challenged with supplying power, fiber-optic, control, and monitoring cables into (and out of) sealed vacuum vessels. Whether due to space restrictions, special geometries, or number and type of conductors, standard glass-to-metal or ceramic feedthroughs never quite fit the bill. Unfortunately, because of limited options, many designers are forced to compromise and go for an off-the-shelf solution.

You don't have to fit a square peg in a round hole anymore. Choose BCE custom feedthroughs for your next design.

http://www.belilove.com/feedthrough

(510) 274-1990

NASA Preferred Reliability Practices: Vacuum Seals Design Criteria

From the Office of The Chief Engineer at NASA - NASA's Preferred Practices.
Courtesy of BCE (Belilove Company-Engineers).

Download the full Vacuum Seals Design Criteria document here.

NASA Preferred Reliability Practices Vacuum Seals Design Criteria from Belilove Company-Engineers

Epoxy Feedthroughs A Better Option Than Glass-to-Metal for Under 200 Deg. C.

Multi-conductor Flanged Epoxy Feedthrough (BCE)

Vacuum and ultra-clean manufacturing applications have continuously challenged designers with the need for versatile and cost effective ways to get power, control signals, fiber optic, and pneumatic lines in and out of a vacuum.

Failures due to contamination, dust, or leaks can be devastatingly costly, in both money and time.

Historically, glass-to-metal (GTM) hermetic seals have been used, but their limited size, shape, pin options, and shielding limitations have frustrated designers. A more accommodating and cost effective feedthrough solution was badly needed.

Enter epoxy potted feedthroughs. While GTM has a distinct advantage in very high temperature applications, in low-to-medium temperature applications newer epoxy resins are quickly gaining ground. Ideally suited for use where continuous temperatures stay under 200 deg. C , the versatility and cost of epoxy feedthroughs make them a clearly better choice. Additionally, in many cases epoxy feedthroughs can be prototyped and small quantities can be provided much more quickly.

Ultimately, epoxy vacuum feedthrough’s greatest advantage is their design versatility and option flexibility. Flanges, threaded connections, circuit board mounts, 120 volt receptacles, thermocouples, pneumatic tubes, Sub D connectors, and fiber optic cables are all examples of options that are easily accommodated. No longer does a designer have to conform their design to a standard glass-to-metal specification. Epoxy vacuum feedthroughs give designers the freedom to have a feedthrough that exactly meets their needs.

Epoxy Vacuum Feedthroughs for Medical Equipment, Analyzers, and R&D Laboratories

The challenges of getting data and
control sensors inside
vacuum equipment.

Scientists and researchers are continually challenged to come up with better ways to read data inside a vacuum environment. Traditional ceramic and glass-to-metal vacuum feedthroughs don’t offer the flexibility of design required. Unique varieties of control and data signals have to pass through the wall. Not only are electrical power and control signals being passed, but fiber optic cables and pneumatic tubing may be included. Ever changing variables, such as the number and types of connectors, unique geometries, and limited available space, make it very difficult to find an off-the-shelf feedthrough. As a result, designers have traditionally been forced to make compromises and specify a feedthrough with some, but not all, of the desired specifications.

Custom epoxy feedthrough by BCE

This reality has led to significant gains in custom epoxy feedthrough development. Epoxy feedthroughs overcome design restrictions. New epoxy properties have been developed that rival ceramic and glass in performance. High performance, clear epoxy potting opens the door for researchers to specify the exact number and type of wires, fiber optic cables, or any other insert they require.

Manufacturers of epoxy feedthroughs 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.

Epoxy vacuum feedthroughs are quickly becoming the preferred vacuum entry device because:

• Can accommodate custom conductors, angles, and shapes.
• Prototypes with the exact number and type of have fiber-optic cables, pneumatic tubing, or run wires.
• Electrical shielding is not a problem.
• Epoxy feedthroughs are cost-effective.
• Comply with outgassing specifications.
• Allow for visual inspection when clear epoxy used.
• Feedthroughs can be mounted directly to flexible circuits and printed circuit boards.
• Elimination of contact resistance.

With the development of epoxy feedthroughs medical device companies, analyzer manufacturers, laboratories, aerospace companies, and other R&D facilities can design their equipment based on optimal size, cost and performance, and not be forced to compromise by ceramic and glass-to-metal feedthroughs limitations.

Because of the constant pressure on vacuum equipment researchers and OEM designers for “better, faster, smaller”, it’s clear that epoxy feedthroughs provide flexibility and options which allow for more efficient and creative design.

For more information regarding epoxy vacuum feedthroughs, contact:
BCE
www.belilove.com
(510) 274-1990

Epoxy Electrical Feedthroughs: A Better Choice

Epoxy Electrical Feedthrough

One thing is for sure. You don’t want to scrap a $125,000 semiconductor wafer because dust or a contaminant gas exploited your process through a faulty electrical feedthrough.  In vacuum or pressurized conditions, getting process control signals and power to and from the work environment is always a challenge. Continually evolving specifications of vacuum requirements, or pressurized manufacturing conditions, push the design limits of electrical feedthroughs.  Failure of the feedthrough is not an option.

In applications requiring ultra-clean environments, feedthroughs are always a concern.  Historically, the product-of-choice for semiconductor manufacturing applications was glass-to-metal or ceramic seals. While providing an excellent seal, they are quite limited by geometry, size, electrical shielding, and fragility. Compounding these limitations, manufacturing requirements continue to evolve making it necessary to deliver more data, provide greater signal shielding, and provide higher power. With glass-to-metal and ceramic seals, this becomes very difficult, expensive, and many times, near impossible.

Enter epoxy feedthroughs. The epoxy materials available today make it fairly easy to design feedthroughs with curves and angles well beyond the capability of glass and ceramic. Epoxy feedthroughs can be applied in many shapes and sizes, provides an excellent seal, and accommodates shielded cable quite nicely.

In terms of cost, versatility, and availability, epoxy feedthroughs have a huge advantage. With manufacturing requirements pushing for smaller and more compact equipment, design versatility of the feedthrough is very important, and something that glass-to-metal feedthroughs can not match. Equipment design conditions often require special geometries of the connector, and using epoxy as the filler makes perfect sense.

Another outstanding advantage to epoxy electrical feedthroughs are in availability. Small production runs are easily and quickly accommodated for testing and proof-of-concept.

Ancillary cost savings of epoxy feedthroughs can be evaluated on design accommodation / size reduction, and on the ability to provide cable harnesses right up to the seal, which dramatically lowers production cost. Time consuming manufacturing processes, such as soldering connectors, is eliminated.

For the most part, epoxy electrical feedthroughs can fit the bill as a better alternative to glass-to-metal or ceramic feedthroughs. Very few exceptions exist, and usually center around concern of the organics in epoxy, but again, these issues are very limited.

For more information contact BCE.