High-performance insulated wiring is critical to success in practically every field of study and each manufacturing process involving high vacuum and ultra-high vacuum (HV/UHV) settings. These environments are associated with demanding working conditions that render standard, commercially-available plastic insulated wiring unsuitable. UHV pressures, for instance, can extend below 10-9 millibar (mbar), while process temperatures may routinely drop as low as -196°C (liquid nitrogen temperature) – down to just a few millikelvin (mK) in some cryogenics applications.
Specialized wiring solutions are subsequently essential to deal with the inherent challenges of HV/UHV processing. Various products based on copper and/or silver plated copper wires and advanced “polymeric” insulation exist, but Kapton wires are among the front-runners.
Here we will outline why Kapton wires are uniquely suited to HV/UHV settings, and provide some insight into when it is appropriate to use flexible Kapton wires.
What are Kapton Wires?
Kapton is the trademark name of DuPont’s ubiquitous high-performance polyimide that was first developed in the mid-20th Century. It was ultralight and displayed exceptional dielectric and thermal characteristics, maintaining key electronic properties across a temperature range from almost absolute zero (0K) up to 400°C (673K). This made it the electronic insulator of choice for aerospace applications, finding myriad uses in commercial and military aircraft alike.
The same critical properties that make Kapton ideal for aviation help them excel in HV/UHV applications.
Matching Kapton Wires to their Applications
Flexible Kapton wire harnesses generally comprise silver plated copper wiring encapsulated in a polyimide polymer wrapping, though various configurations are available to satisfy distinct performance parameters. Coaxial cables wrapped with Kapton are readily used as universal, shielded connectors. Twisted pair wires are ideal for in-vacuum motors. Specialized Kapton-insulated Manganin® & wires, meanwhile, are often diagnosed for cryogenic applications.
Each of these market segments benefits from the high dimensional stability and thermoelectric performance of Kapton, but the inherent flexibility of the polymer is often a unique selling point too. High-flexibility Kapton wires are offered with both single, plain copper strands and multi-stranded silver-plated copper conductors. These are perfect as cost-effective general-purpose wiring for signaling and sensing in UHV applications with low to medium current requirements. Some highly flexible Kapton wires offer higher current performance (<20A) for short periods.
Flexible Kapton Wires from Allectra
Allectra is one of the UK’s foremost designers and suppliers of HV/UHV components for processing and research applications. We offer a wide range of Kapton wire solutions for your vacuum requirements. Contact a member of the Allectra sales team today to learn more about our finely-tailored wiring range.