All posts by Nadine LAURET

Heated cable inlet for climatic chambers

Target market :

Manufacturers and operators of climatic chambers.

Challenge :

Prevention of condensation at the cable inlet inside and outside of climatic chambers.

Description of the problem without a heated cable inlet :

Condensation at the cable inlet due to climatic differences between the inside and the outside of the chamber.

Condensation on the measuring cables inside and outside of the temperature test chamber when using a standard inlet.

Risk :

High financial risk if long-term climatic tests have to be cancelled because of condensation in the climatic chamber. Condensation damages the test materials and affects the climate regulation in the chamber.

Solution :

Heated cable inlet from THERMOCOAX Isopad® GmbH. A standard inlet with geometric properties, the best possible sealing and a heated area inside of the cable inlet.

Test results with a heated cable inlet :

Decrease in the amount of condensation formed inside the climatic chamber by approx. 95% and by 100% outside of the climatic chamber!

The risk of failure is extremely reduced because there are hardly any condensation drops in the chamber (airflow can spread the drops onto the test material).

No water on the floor outside the chamber. The risk of slipping is eliminated, thereby extremely reducing the risk of accidents !




Successful test campaign on neutron sensors

THERMOCOAX has finalized a test campaign on neutron sensors.

reacto Pool : experimental fixtureReactor Pool : experimental fixture

Despite stringent time constraint, a highly professional IJS team was prompt to react and welcome a team conducted by THERMOCOAX and relying on the best internationally recognized experts from different European nuclear organizations.

Multiple irradiation tests have been carried out.

IJS reactor being very well characterized, results are confirmed to match with our stringent expectations: perfect matching between theory and practical results!

An additional demonstration of the THERMOCOAX mature technology readiness.



THERMOCOAX has over 60 years of expertise in instrumentation and heating solutions. It provides solutions in the world of nuclear, aerospace and semicon industries. It design, qualify and manufactures sensors for harsh environment with a focus on nuclear on temperature and radiation measurement.

 About IJS Jozef Stefan Institute

IJS Jozef Stefan Institute in Slovenia has over 50 years of expertise. Reactor Infrastructure Centre (RIC) department is operating a  TRIGA Mark II reactor. Reactor physics department is directed mostly towards development of new calculation methods for research and power reactors. Several program packages for reactor calculations both for TRIGA research reactor and Krško nuclear power plant. Jozef Stefan Institute also study advanced fourth generation reactors, advanced neutron sources and data and materials for fusion technology are also studied.


TRIGA reactor
TRIGA reactor

THERMOCOAX ISOPAD Gas line heating Jackets

Gas line heating jackets for high purity gas delivery systems


silicone Jacket
Gas line heater

THERMOCOAX is involved in many levels of the wafer manufacturing processes working with OEM all around the world.

We provide thermal solutions for applications such as lithography, deposition, etching, ion implantation, or annealing.

While developing our business in the ALD deposition processes, we understood the need of our customers to heat the high purity gas delivery systems from the ampoule to the deposition chambers.

Temperature control is extremely important in the deposition process.

This is why industrials need to have a high performance gas delivery system in terms of management of the gas flow rate and temperatures.

Transfer line heating jackets are used for both solid and liquid precursor management in semiconductor deposition processes.

The heating temperature requested is in the range of 80°C to120°C. Typically, the range of thermal solutions is provided by our German subsidiary ISOPAD, specifalist in the development and manufacture of customized silicon heating solutions.

The main concern of our customers was the need to keep the temperature uniform all the way from the gas generation ampoule to the deposition chamber. This complex way includes straight tubes, Tees, elbows (2P,3P), VCR, valves, manifolds and complex components.

Each delivery system is specific to the customer process.

That  was the challenge for THERMOCOAX ISOPAD.

Another limitation of this application is the use of jackets that must be installed, positioned as easily as possible in an environment with limited space.

ISOPAD has a lot of experience in high performance silicon jackets.

The silicone jacket is a well-known product for our company, all the expertise we have gained from working with our other OEM customers have been used to design and construct a high volume production solution.

All core competencies are in house, only the raw materials are bought in.

Many years ago, we developed filter heating jackets for the biotechnology industries, built with seamless silcone rubber that does not need affixing.


Isopad Silicone Jacket
Silicone Jacket

These jackets have a real advantage on the market because of the flexibility they provide  in terms of positioning and ease of cleaning.

The one-piece molded design is formed out of a two-component silicone rubber compound that fits around the filter housings without any affixing methods that may  not be compliant for use in those production processes.


The target for THERMOCOAX ISOPAD to adapt this solution to the SEMICON applications was:

  • to adapt this technology to smaller diameters, and to complex shapes.
  • To achieve the customer specifications on uniformity over the full line assembly
  • To find good materials for clean-room use and respond to the SEMICONDUCTOR requirements in term of low contamination properties.

Due to our expertise, we quickly managed to design and prototype a full line assembly responding to our customers’ demanding specifications.


The advantages of our solution:

These heating jackets provide an innovative design on the market with short delivery time.

Built with seamlessly-molded silicone rubber, these jackets offer a better thermal performance due to a close-fitting design and a high uniformity over the complete line.

With a product that has demonstrated a longer service life than existing solutions, we can deal with any installations of new deposition systems, but also spare parts for installed systems.

Applications that addresses our offer:

PeCVD, PVD, ALD, Epitaxy, ETCH, Wafer packaging, cleaning chamber processes etc.



 Technical Performance

. Custom-built line assembly

. Seamlesly-molded silicone

. Close-fitting design

. Better thermal performance, heat 68°F (20°C) up to 275°F (135°C)

. Reduced installation faults

. Lower overall risk of production downtimes

. Longer service life

. Easy to install & remove

. Outgassing according NASA standards


THERMOCOAX is a certified for Copy Exact:


  • Thermal gas flow uniformity: ± 5°C in the complete line assembly
  • Better thermal performance, heat 68°F (20°C) up to 275°F (135°C)

(minimum 1 meter of length)

  • Reduces installation faults
  • Lower overall risk of production downtimes


  • Jacket: silicone rubber, seamlessly molded, easy to clean, IP68 standard
  • Minimum gas line diameter: ¼ inch OD
  • Affixing technology: ” snap-on ” design by molding, easy to install and remove
  • temperature:   200 °C
  • UL-V0 standard, FDA-approved ultra-low emission material


Heater design to fit standard components used in weldments

  • Straight tube
  • Elbows (2p, 3p)
  • Tee
  • VCR fitting, etc.
  • Specially-formed and customised heaters for valves, manifolds and complex components

This high purity gas line heater development has been combined with the development of ampoule and canister heaters which are used in all deposition processes and with RF thermocouples used in the plasma environment to control the temperature in the deposition chamber.

Ampoule heater

THERMOCOAX meets the requirements of the SEMICON market in terms of repeatability, temperature uniformity, production control, quality monitoring, and COPY EXACT high volume manufacturing.

For high volume manufacturing, THERMOCOAX works with a continuous improvement strategy for:

  • Design
  • Manufacturing process
  • Cost reduction


THERMOCOAX is highly adaptable to specific customer requests





Heating System for SMA actuators

You are looking to replace your pyrotechnic actuators with shape memory alloy technology for your space applications ? We have the most advanced industry-proven solutions.

Spacecrafts require variety of mechanisms to accomplish the mission. The typical functions are deployment, articulation, positioning, displacement.

Pyrotechnic separation nuts, paraffin actuators and others devices are hazardous for the satellite, regarding shocks waves generation and potential risk of contamination.

Shape Memory Alloy ( SMA ) technology equipped with inner heating element, offers smooth and slow behavour, higher cleanliness result and good vibration & shock resistance.

Thermocoax addresses this new market with miniature and powerfull heating element, same components already demonstrated on propulsion and thermal management on board satellite.

Main applications are single one time used valve, Hold Down & Relieve Mechanism (HDRM), Pin Puller, deployment Hinge.

Heating SMA
Heating coil

THERMOCOAX heating space products with Spacecraft Electrical Propulsion System

New Generation of Pre-Heating Solution for : Hall-Effect Propulsion Thruster

heating ring ring


For 15 years, THERMOCOAX has been a worldwide key player in designing, developing and manufacturing heating systems for the space market.

We provide solutions for :

Ground applications :

  • R&D programmes with institutes
  • Ground equipment

Flying models :

  • Heating management systems at 50 & 100 volts for Satcom
  • Catalyst bed heaters for chemical propulsion
  • Heating solutions for Hall-effect thrusters

Scientific Mission :

  • Heating systems on Curiosity Rover
  • Heating elements on ISS for MSL
  • Heating elements for pyrolysor on Cassini-Huygens Titan probe

heating technology THERMOCOAX heating solution

Technical Application of pre-heating ring

The new generation of communication satellites is improved with more power available (13kW for E3000 platform) and allows the use of electrical propulsion systems for orbit raising and for all station-keeping manoeuvres, wheel offloading, station relocation and final re-orbiting for disposal.

The electrical propulsion system allows a significant reduction in spacecraft mass. A disadvantage is the average length of 8 months to raise the final orbit in comparison to a few days for chemical propulsion.

The first platform to be equipped with the THERMOCOAX pre-heating ring is the EUTELSAT172B, produced by Airbus Defense and Space, equipped with Russian FAKEL EPS.

Space electrical propulsion hall effect thruster

For faster startup and to protect the thruster from premature erosion, a pre-heating system is installed around the electrical thruster. Each pre-heating ring supplies 28 watts.

Technical Description of heated Ring

We use our best mineral-insulated cable.

Mineral-insulated cable with 2 resistive wires welded together at the tip to make one electrical loop.

Redundancy can be reached by using 2 separate heating cables with an outer diameter of 1mm or only 1 cable with 4 wires for 2 heating loops with a minimum outer diameter of 1.5mm.

drawing of heating element heating element


The cables are installed and brazed in the metallic ring.

To get the perfect dimensions and tolerance, the ring is reworked and then polished.

3D drawing of heating ring ring


3D drawing of polished product Finished product cleanless


Catalyst Bed Heater :

  • 2 redundant electrical loops
  • Nominal power supply: 28 to 55 volts
  • Power version per loop:
  • 30 watts under 70VDC
  • 60 watts with 2 loops activated
  • Max exposed temperature:
  • 1000°C with Inconel

Other power and voltage available.

Mineral-Insulated Cable :

Version exposed to 1000°C :

  • Inconel 600 sheath
  • 4 nickel-chromium wires

Xray cable Xray four wires heater


Lead Wires :

  • 4 wires
  • Color code for each loop
  • AWG24 or 26
  • Strength 1.4kg

Acceptance Test Criteria of the catalyst bed heater :

  • Helium Leak Test
  • X-ray of the ring
  • X-ray of the junction MIC/lead wires
  • Lead attachment strength test
  • Visual and mechanical examination
  • Overvoltage
  • Line resistance
  • Insulation resistance under 500 volts
  • Burn-in test
  • Dielectric 100/300/500VAC, 60Hz/60s
  • Weight
  • Final Manufacturing Report

 Test List for Qualification Program

THERMOCOAX manages and conducts the qualification test programme in accordance with our customer’s specification.

Our engineers write the QTP for customer approval prior to running the test.

Most of the tests (thermal, humidity, electrical, etc.) on the space grade heating solutions are performed in THERMOCOAX’s labs.

Tests requiring heavy equipment (vibration, acceleration, shocks, etc.) are subcontracted to external laboratories or supported by our customers with the complete propulsion system.

List of Typical Qualification Tests on Catalyst Bed Heater :

  • Vibration
  • Acceleration
  • Mechanical shock
  • Pyrotechnic shock
  • Helium leak
  • Burn-in
  • Humidity
  • Hot firing
  • Electrical cycling
  • Thermal cycling
  • Lead attachment
  • Dielectric
  • Destructive physical analysis
  • X-ray Examination


vibration qualification graph Example of vibration spectral

Packaging and Cleanness :

Packaging is designed specifically to ensure excellent condition of the catalyst bed heater during transportation and storage :

packaging vacuum packaging


packaging marking packaging


THERMOCOAX supplies the new Hall-effect thruster with 1500 and 5000 watts, here are a few examples :

  • SMART1
  • Alphabus
  • Alphasat

To come :

  • SSL1300
  • E3000e
  • Boeing 702 platform


THERMOCOAX is the major player for onboard heating solutions for electrical thrusters and is proud to participate in challenging international space programmes.

THERMOCOAX’s focuses on high-quality heating products for maximum stability and repeatability during operation. We have understood our customers’ challenge to manufacture spacecrafts for over 20 years for a better life for human beings.

New large constellation programmes are currently in construction, THERMOCOAX is now ready to support the market with high-reliability and high efficiency heating ring for electrical thruster.


In-Core water level detector

Over the last decade, THERMOCOAX has developed a range of Ex-Core accident resistant cabling systems and In-Core instrumentation assemblies for Gen 3 reactors.

Based on THERMOCOAX unique expertise and taking profit of the extreme robustness of its MIneral Cable technology, THERMOCOAX has developed, tested and qualified a Reactor Pressure Vessel Level (RPVL) detector.

Before making the detector commercially available, THERMOCOAX has partnered with SIET ( to verify detector functionality at normal and abnormal conditions.

Some results have been published during the latest BEPU 2018 Conference. Click here to read an abstract

THERMOCOAX Nuclear team remains available for further information.

Innovative flange immersion heaters for liquid fuel


The project to develop a high-efficiency immersion heater started a long time ago at Thermocoax with a particular R&D project for high purity aluminium foundries.


Then we decided to adapt our technology to heating applications for the storage of heavy fuel. We designed an innovative flange immersion heater offering longer lifetime than existing solutions.

The technology is based on THERMOCOAX Mineral Insulated Cables that offers high reliability, high resistance, long lifetime and a fully insulated heating solution.


A full range of Flange Immersion Heaters low density is now available with a total length above the flange of maximum 2 meters.

To respond to the needs of fuel storage applications in tanks where the accessibility is reduced and where small footprint heating systems are requested, we limited the length of the immersion heaters and made our design with DN100 & DN200 flanges only.

The challenge was to develop a design with high total power, a Low power density and a small footprint while offering a natural movement of the fluid through the heater.

Another challenge was to make a comfortable maintenance design, with a strong mechanical resistance and that can resist the immersion in petroleum-based liquids with 100% energy efficiency.


We based the design on a strong mechanical stainless steel structure with mineral insulated heating cable spiralled and firmly fixed on the structure.

In the middle of the heater, a stable Stainless steel square tube is welded to the flange. Another construction is fixed on this tube so that a solid essential strength is created.

The heating cables are held by particular carrier profiles which are connected to stainless steel discs and fixed to the middle tube.

We managed to make a design where each heating cable is independent, and due to an innovative assembly, each heating cable can be replaced independently for easy maintenance of the Immersion Heater on site.

Mineral insulated cables with 316L stainless steel sheath are used to offer to the heater a high resistance for immersion in main petroleum-based liquids and also asphalt, tar or other dense or highly viscous components.

We also wanted to offer a solution with better fluid circulation through the heater and with more contact between the fluid and the heating surface than with existing solutions on the market.

To meet this need, THERMOCOAX ISOPAD Immersion Heaters can have up to 3  layers of heating elements while keeping enough space for fluid circulation. The multilayer design increases the contact surface between the fluid and the heaters for a better heat transfer efficiency.

The clearance between two spires for the movement of the fluid through the heater is between 9mm and more than 15mm depending on the total power of the Immersion Heater.

All our immersion Heaters can be manufactured with an integrated thermocouple or PT100 for temperature control, with flange with screw plug and junction box.


  • Fuel, light diesel fuel, standard diesel fuel, maximum load 1 – 2 w / cm², materials: 321, 316l
  • Heavy fuel, maximum load 0,5 – 3,5 w / cm² according to grade, materials: 316l
  • Diesel, kerosene, maximum charge 3 – 3.5 w / cm², materials: 316l
  • Machine oil, maximum load 2 – 3.5 w / cm², materials: 316l
  • Mineral oil, maximum load 0,5 – 3,5 w / cm² according to temperature, materials: 321, 316l
  • Lubricating oil, maximum load 2,3 w / cm², materials: 321, 316l
  • Asphalt, tar and other heavy or highly viscous components

High-end heating solutions for SEMICON ALD deposition processes

THERMOCOAX is involved in the worldwide SEMICON market with High-end heating solutions based on Mineral Insulated cable technology.

We work on many levels of the wafer manufacturing process such as lithography, deposition, etching, ion implantation, or annealing.

With the evolution of the technology of 3D transistors, we focused our development on the ALD deposition process.

We meet the requirements of the SEMICON market in term of repeatability, temperature uniformity, control in production, quality monitoring, and COPY EXACT High volume manufacturing.

Due to our 60 years of experiences in high tech projects,  our engineering capability, our production tools, our control processes, our quality procedures and our adaptability are fully in line with the requirements of our SEMICON OEM customers.

We have decided to present in this paper our development on heating chucks for ALD processes

We have developed heating chucks dedicated to the SEMICON ALD, offering a high thermal uniformity on all the surface of the chuck, a great flatness and high dimensional stability, with no brazing presence outside the chamber.

We first focused our studies on the temperature uniformity over the entire surface of the chuck at High-temperature.

We started with the prototyping phases with our OEM customers.

Each ALD process has his own specifications. So, in order to better meet the needs of our customers, we set up a team of engineers dedicated to the SEMICON market.

We have acquired in-house testing tools, and we developed our own test systems.

Up to date, we have developed chucks with up to 7 separate heating zones.

A thermocouple type K, N or J well positioned makes it possible to control the temperature of each heating zone independently.

We manage to develop multizone heating chucks with High-temperature uniformity responding to the SEMICON ALD specifications :

Complex thermal FEA – 3D THERMAL MODELING – 1.6°C surface homogeneity



The flatness of the heating chuck is also one of the most important parameters in the ALD specifications.

We work on chucks with diameters up to 450mm (18 “).

We design, machine the chucks in-house, and control the dimensions with high-performance tridimensional CMM control facilities.

Those metal chucks can be of stainless steel, Inconel or special Alloy offering high dimensional stability.

  • Critical dimensional tolerances

 We adapt the feedthrough by offering custom bushings and flanges.

 Our heating chucks are designed to be used in an ultra-high vacuum environment.

  • UHV Vacuum < 10-7 Pa

THERMOCOAX has developed specific High-temperature ceramic / metal connectors compatible with high vacuum.

Because of the cleaning operation necessary for an ALD process, we developed metal chucks with a specific alloy that can resist the aggressive cleaning gas withstanding.

We also offer optional:

  • Cooling channel
  • Gas line
  • Vacuum wafer sucking
  • Anti-slice grooving



 To ensure the quality requirements of the SEMICON market, THERMOCOAX built a new factory in France fully dedicated to the SEMICON market with a dedicated R&D & manufacturing team.

We manufacture series according to the COPY EXACT specifications of our customers.

Our manufacturing process is fully controlled :

– Traceability,

– Subcontractor assessment,

– Internal & External audits

– Regulatory compliance

We set up an organization in project mode to manage large production programs for a permanent improvement of our performances.

Our industrializing performance is controlled by scores :

  • Failure mode and effects analysis (FMEA)
  • Statistical Process Control (SPC)
  • Process Flow
  • R&R calculation method

For High Volume Manufacturing, THERMOCOAX works with the strategy  of permanent improvement in terms of :

  • Design
  • Manufacturing process
  • Cost reduction

  THERMOCOAX offers high adaptability to customers specific requests.

THERMOCOAX has a full scaled presence in the US and serves ASIA directly.


THERMOCOAX to build Magnetic Diagnostics Flux Loops Cable Assemblies for ITER

THERMOCOAX, the expert in nuclear cabling systems and instrumentation ,has been awarded a contract by ITER.

THERMOCOAX will manufacture Magnetic Diagnostics Flux Loops Cable Assemblies. This innovative cable assemblies will be based on Mineral Insulated cable technology and will be installed in the ITER Vacuum Vessel.

This project represents an important milestone in THERMOCOAX nuclear business unit expansion and pave the way for others applications in FUSION reactors.

THERMOCOAX offers support to its customers through the design, delivery and support phases of a program.


THERMOCOAX has over 60 years of expertise in cabling solutions and instrumentation. It provides solutions in the world of nuclear, aerospace and semicon industries. It design, qualify and manufactures sensors for harsh environment with a focus on nuclear on cabling solutions and connectors.

About ITER

ITER (“The Way” in Latin) is one of the most ambitious energy projects in the world today. 35 nations are collaborating to build the world’s largest tokamak, a magnetic fusion device that has been designed to prove the feasibility of fusion as a large-scale and carbon-free source of energy.
The heart of a tokamak is its doughnut-shaped vacuum vessel. Inside, under the influence of extreme heat and pressure, gaseous hydrogen fuel becomes a plasma.