Thick Film Heaters · Fluid & Instant Water Heating
Instant Water Heating Thick Film Modules
Continuous to 300 °C, wound for 110-220 V, built to UL 499 / IEC 60335 / RoHS. Set the outline, the voltage and the wattage on the drawing below and it redraws to them.
Instant Water Heating Thick Film Modules are continuous to 300 °C, wound for 110-220 V, watt density 20 W/cm² in free air and 100 W/cm² bonded to a heat sink, about 2 mm to 4 mm thick. The outline is cut to your drawing, up to 150 x 300 mm in one piece. It does not limit its own temperature: a thermostat, a thermal cutoff or a control loop with an independent over-temperature channel belongs in the design.
Continuous temperature
to 300 °C
Supply voltage
110-220 V
Watt density
20 W/cm² free air / 100 W/cm² bonded
Thickness
2 mm to 4 mm
Maximum one-piece size
150 x 300 mm
These are the process limits for this construction, not the rating of a finished part. The ratings of your heater come from the drawing it is built to, and the watt density it can carry depends on what it is bonded to.
Outline & Specification Builder
Set the outline, the size, the voltage and the power you have in mind. The drawing
redraws to match, and the panel works out the heated area, the watt density and the current — then checks
that watt density against what this construction survives in free air and bonded to a heat sink. Those two
limits are different by several times, and it is the difference that decides whether a heater lasts.
Fills in the form below; attach your outline drawing or DXF there.
Request a Quotation for Instant Water Heating Thick Film Modules
The form below follows the current technical drawing configuration. Change the drawing values above and the request details update automatically.
Every row below is a starting point for the customizer above — pick any size and the drawing will redraw to that row.
Parameter
Specification
Limit / note
Construction
Glass dielectric and resistor pastes screen printed and fired onto the substrate, then laser trimmed to resistance
Fired, bonded or encapsulated as a single assembly
Substrate
304 stainless flow plate
The substrate carries the heat and the mechanical load
Thickness
2 mm to 4 mm
Substrate plus element system
Maximum size, one piece
150 x 300 mm
Limited by the firing or curing fixture
Dimensional tolerance
u00b10.2 mm on the substrate, u00b10.1 mm on printed features
On the machined substrate
Supply voltage
12 V DC to 400 V AC
Circuit is designed for the ordered voltage
Resistance tolerance
u00b110% standard, u00b15% selected
Thick film resistors are laser trimmed where a tighter band is required
Watt density
20 W/cmu00b2 typical, 100 W/cmu00b2 maximum in a wetted application
Achievable because the heat is generated in the surface being cooled
Maximum working temperature
+300 u00b0C at the element system
Of the element system; the substrate itself tolerates more
Dielectric strength
2500 V AC, 1 minute
One minute, circuit to substrate
Insulation resistance
greater than 100 Mu03a9 at 500 V DC
At 500 V DC
Terminations
Welded tabs, crimp terminals or soldered leads depending on temperature
Soldered, welded or crimped as the temperature allows
Mounting
Bolted, brazed or welded into the assembly; flatness of the mating face is critical
Flatness of the mating face matters more than clamping force
Sensor and control options
Printed PTC or NTC track, or a bonded thermocouple
Integrated into the same firing or bonded to the substrate
Certifications available
UL 499, IEC/EN 60335, RoHS, REACH, CE
Construction level
Flow rate
0.5 to 6 L/min depending on rise and power
Power required is 70 W per L/min per u00b0C of rise u2014 check the supply before the heater
Dry-run protection
Mandatory: NTC or thermal cutoff on the outlet face
A dry thick film plate at 100 W/cmu00b2 fails in seconds, not minutes
Instant Water Heating Thick Film Modules are made to order rather than supplied from a size list, because the outline is whatever the surface being heated requires. What is fixed is the construction: thick film heaters, with the limits set out in the capability table below and the reasoning behind each of them underneath it.
What Are Instant Water Heating Thick Film Modules?
Instant Water Heating Thick Film Modules are thick film heaters. They are specified by supply voltage and outline together with the outline drawing, the wattage or the temperature to be held, and what the heater is bonded to — that last one decides the permissible watt density and is the question a quotation cannot skip. The construction is built and tested to UL 499 / IEC 60335 / RoHS.
Construction & Insulation System
There is no separate element. A glass dielectric and a resistor paste are screen printed onto the substrate — 304 or 316 stainless, 96% alumina, or anodised aluminium — and fired at around 850 °C, then laser trimmed to resistance. The heated surface IS the substrate, so there is no adhesive, no air gap and no interface in the heat path, which is why watt densities an order of magnitude above any flexible construction are achievable. It is also why every fluid application needs dry-run protection: with no water over it, a plate at 100 W/cm² has seconds of margin, not minutes.
Watt Density
In free air, with nothing conducting heat away from it, this construction carries 20 W/cm². Bonded over its full area to metal that carries the heat off, it carries 100 W/cm². The second figure is not an upgrade of the first — it is a different operating condition, and a heater ordered at 100 W/cm² and then run unbonded fails within minutes. Divide the wattage you need by the area you have before anything else: if the answer is above the free-air figure, either the area grows or the heater gets bonded down.
Typical Applications
Instant water heating in coffee machines, dispensers and sanitary ware; medical fluid and blood warming; dialysis and analyser fluid lines; laboratory hotplates and steam generation — applications where the fluid has to be heated fast, with no tank, no warm-up and no immersion element in the flow.
Specifying the Instant Water Heating Thick Film Modules
The supplies this construction is most often wound for are 110-120 V AC and 220-240 V AC. Each has its own page, with the resistance and current the wattage works out to at that voltage and what that means for the leads.
Where the environment decides the build rather than the wattage, the insulation page the one to read: Stainless Steel Substrate (thick film). Each is written to the same headings, so the comparison is like for like.
Specified by the temperature it has to hold: 80 °C to 120 °C and 120 °C to 150 °C. Each page covers the watt density that band allows in free air and bonded down, and the control and over-temperature arrangement that goes with it.
This construction is built and tested to UL 499 and IEC/EN 60335 — worth checking against the standard your own end product is certified under, because a part built to one scope does not automatically satisfy another. For the equipment and duties this construction is actually specified for, see where instant water heating thick film modules are used.
Inside the plant
Manufactured in our own plant
This heater is laid out, wound or etched, laminated, cut, tested and imaged in-house. The stages below are where its resistance tolerance, its temperature uniformity and its insulation integrity are actually decided.
01
Circuit design & layout
The customer outline comes in as a drawing or a DXF, and the element is laid out inside it: conductor gauge from the voltage, path length from the resistance, pitch from the watt density wanted at each part of the surface. Where the load needs more heat at the edges than in the middle, that is decided here, in the geometry, not later with more power.
Calculated resistance and watt density checked against the construction limits before any tooling is cut.
02
Element preparation
Wire-wound elements are wound on a glass carrier at the calculated pitch; etched-foil circuits are photo-imaged and etched from Inconel or copper foil to a trace width held within 0.05 mm. That tolerance is what makes the resistance repeatable from lot to lot, which is what makes the temperature repeatable.
Trace width and element resistance measured before lamination — a circuit out of tolerance is scrapped here, not after it is sealed inside the part.
03
Lamination & vulcanising
The element and its sensor are laid between the insulation and pressed under heat: silicone is vulcanised, polyimide and PET are laminated with a high temperature adhesive, epoxy plates are potted under vacuum so no voids are left anywhere in the heat path. A void is not a cosmetic defect — it is a place the heat cannot leave from, and it becomes the hot spot that ends the part.
Press temperature, pressure and dwell recorded per lot; potted plates checked for voids.
04
Die cutting & leads
The outline is die cut with radiused corners — a die does not cut an inside corner, and a sharp corner in a film is where a tear starts. Leads are crimped or soldered and strain relieved at the exit, and connectors are fitted to the harness drawing so the assembly line never has to solder.
Outline to ±0.5 mm on film, ±1.5 mm on silicone; lead pull-out tested per lot.
Third-party video, selected automatically for this topic. It is not produced by Heating Film and is not a specification source — use the tables on this page for dimensional data.
Frequently Asked Questions
What sizes do Instant Water Heating Thick Film Modules come in?
There is no size list. Instant Water Heating Thick Film Modules are cut to your outline, so the size is whatever your drawing says, up to 150 x 300 mm. Larger areas are built as separate zones with their own circuits. Send a dimensioned drawing or a DXF and the quotation comes back against that outline.
How much power can Instant Water Heating Thick Film Modules take?
Two figures, and they are not interchangeable. In free air, with nothing conducting heat away, 20 W/cm². Bonded over its full area to metal that carries the heat off, 100 W/cm². A heater ordered at the second figure and then run in the first condition fails within minutes, so the quotation asks what the heater is bonded to before it asks anything else.
How hot can Instant Water Heating Thick Film Modules run?
300 °C continuously. That limit belongs to the insulation system — Stainless Steel Substrate (thick film) — not to the element, which would tolerate a good deal more. It is a hard ceiling: above it the insulation degrades, and no derating scheme buys headroom. Past 300 °C the construction has to change rather than be pushed.
What protects Instant Water Heating Thick Film Modules from overheating?
Nothing in the heater itself — a heater is a resistor and has no opinion about temperature. The protection is a separate part of the design, and on this construction it is normally a bimetal thermostat or a one-shot thermal cutoff fitted inside the insulation, in series with the element. It can be built into the heater at manufacture, which is both cheaper and more reliable than adding it to the assembly afterwards, and it is a different component from the sensor that closes the control loop: the case the cutoff exists for is the loop failing on.
How are Instant Water Heating Thick Film Modules fitted?
They are clamped between machined faces with a thermally conductive interface, where flatness of the mating face matters more than clamping force.
What voltages are Instant Water Heating Thick Film Modules available in?
110-120 V AC and 220-240 V AC. The element is wound for the voltage ordered — it is not a switchable range, and running a heater at a voltage other than the one it was wound for changes its power by the square of the ratio. Resistance is held to u00b10.2 mm on the substrate, u00b10.1 mm on printed features.
What is the dielectric strength of Instant Water Heating Thick Film Modules?
2500 V AC, 1 minute, with insulation resistance above 100 MΩ at 500 V DC measured after the dielectric test. Both are tested on every unit rather than on a sample, because a heater that fails this test in service fails it into whatever it is bonded to.
How do I get a quotation?
Set the outline, size, voltage and power in the builder on this page and send that configuration through, or attach a drawing. The quotation needs six things: the outline, the supply voltage, the power or the temperature you need to hold, what the heater is bonded to, the ambient it works in, and the quantity. With those, a quotation comes back within one business day.
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