Insulated wires are rapidly becoming ubiquitous. Whether that is in research fields such as surface or materials science or the semiconductor manufacturing industry, the prevalence of insulated wires has now become a recognized fact.
They find uses in high vacuum and ultra-high vacuum (HV/UHV), where they power high-technology electronics, connect instrumentation and motion elements, and couple signals to and from detectors.
There is a great deal of stringent measurement and experimental criteria placed on these wires, which include limited outgassing, higher stability, and high-temperature compatibility, as well as many more. When performing in the most demanding operating conditions, manufacturers advise the use of Kapton wires.
Kapton-insulated wires have several qualities that render them ideal for such usage. These include their notable low-thermal conductivity (W/mK) (even at extreme temperatures), their unparalleled thermomechanical stability, and their limited outgassing, all of which make them suitable for use in demanding HV/UHV applications. The Kapton wires available from Allectra are detailed in this article.
HV/UHV: Why Use Kapton Wires?
Wiring harnesses are required for electronic processes in HV/UHV systems, which retain their distinct electronic/dielectric properties, even at pressure regimes below 10-9 mbar. To protect and ensure the internal conductor’s integrity, the insulation must exhibit low-thermal conductivity at severe temperatures.
Kapton is a proprietary polyimide that has superior mechanical stability across a particularly wide range of temperatures of around -269 – +400 °C (-452 – +752 °F). Such mechanical stability arises thanks to Kapton’s low thermal conductivity, which allows shape retention in high and processing temperatures.
Kapton, when used in wiring, conventionally sheaths silver-plated copper conductors of ranging diameters, which may be the site of current/voltage fluctuations as a result of thermally induced physical variations. When using high-performance Kapton to insulate these single or multistrand wires, you guarantee an electrical supply that is strong and stable for the duration of the processing, even in applications as extreme as HV/UHV thermal processing and cryogenics.
Thanks to their low outgassing rates, which ensure that vacuum integrity is protected against possible compromise from the release of gaseous species from polymeric wire sheaths, Kapton wires are also implemented across the board in HV/UHV processes.
The degradation of wiring can cause any number of faults due to thermal deformation or radiation damage. This can subsequently restrict process yields or affect the accuracy of results. The solution is compounding the highest quality conductor materials with high-performance insulation and ensuring testing of the product to guarantee vacuum compatibility.
Kapton wires routinely surpass these restrictive parameters. However, until recently, one draw-back of Kapton-insulated wires was their inability to endure or resist radiation damage, which can arise from multiple and varied sources such as infrared (IR), electron beams, x-ray, and so on.
This drawback has been resolved with Allectra’s recent introduction of its new range of radiation-resistant Kapton-insulated wires, KAP301.
Kapton Wires from Allectra
Allectra’s recent expansion of its Kapton-insulated wires to include the new multi-stranded radiation-resistant KAP301 ensures its products can fulfill an even wider range of purposes.
These aforementioned KAP301 Kapton wires have undergone rigorous testing for high-voltage performance at many temperatures, controlling for vacuum compatibility throughout radiation exposure.
The results of these experimental tests underlined the long-term performance of Allectra Kapton wires, in a temperature range that spans from -269 °C (4Kelvin) up to 300 °C and radiation resistance of 109 Rad = 107 Gy. In terms of radiation resistance, there are no other Kapton-insulated wires currently available that can match Allectra’s KAP301 range.
The Allectra KAP301 range also incorporates multistrand wire 0.25 mm diameter, 0.35 mm diameter and 0.6 mm diameter in addition to coaxial wire, thermocouple wire, type K and N and Twisted Pair cable screened with outer insulation.
This information has been sourced, reviewed and adapted from materials provided by Allectra Limited.
For more information on this source, please visit Allectra Limited.