HDG01b F L E X I B L E H E AT E R S D E S I G N G U I D E Flexible Thermofoil™ Heating Solutions | Polyimide, Silicone Rubber, Mica, Thermal-Clear™ Precision Heating for Medical Diagnostics, Defense, Aerospace, Telecommunications & Other High Reliability Industries
Minco: A Critical Component of your Success Minco has been designing and manufacturing critical components since 1956. During the past five decades, we've grown into a global company with four product lines: Flexible Thermofoil™ Heaters Sensors Flex Circuits Instruments Minco today: global and growing Minco's engineering and manufacturing plants employ over 1000 people worldwide.
Thermofoil™ Solutions for Heating Flexible Thermofoil™ Heaters Custom and integrated components Introduction Design Guide Minco operates four different product divisions, all coordinated in the same facility for faster, seamless integration that can boost your time-to-market. This makes us unique in our ability to customize and integrate components into turnkey assemblies and complete thermal, sensing and flex circuitry solutions.
Defense and Aerospace Minco's flexible Thermofoil heaters, flex circuits and sensors provide a turnkey solution for this point-of-care blood analyzer. The integrated component design improves reliability and reduces cost from the original design by eliminating 3rd party wire harnesses and printed circuit boards (PCBs). Flexible Thermofoil heaters are used in Defense and Aerospace applications where ruggedness and reliability in harsh conditions is required.
Selecting a Minco Heater 1. Choose insulation type Introduction Pick from the available insulation types. When selecting insulation consider temperature range, maximum resistance density and maximum heater size. Insulation options are available on page 7. 2. Choose installation option Proper installation is crucial for optimal heater performance. Determine the best method to install flexible heaters in your application so you can achieve desired results in your thermal system.
Silicone Rubber Mica Optical Grade Polyester Temperature range -200 to 200°C -328 to 392°F Silicone rubber -45 to 235°C -49 to 455°F Mica -150 to 600°C -238 to 1112°F Optical grade polyester -55 to 120°C -67 to 248°F Max. resistance Comments density* 560 mm × 1065 mm 22" × 42" 560 mm × 2285 mm 22" × 90" 560 mm × 1168 mm 22" × 46" 280 mm × 560 mm 11" × 22" 70 Ω/cm² 450 Ω/in² 31 Ω/cm² 200 Ω/in² 3.
Heater Installation Introduction Versatile Thermofoil heaters allow a variety of mounting methods. Design Guide Proper installation is crucial to heater performance. The heater must be in intimate contact with the surface beneath, as any gaps can block heat transfer and cause a hot spot resulting in premature heater failure.
Maximum Watt Density The watt density tables on this page show the maximum allowable power for each heater type, expressed in watts per square inch, or centimeter, of effective area. The rating depends upon the heater’s insulation/internal adhesive, heat sink control temperature, and the mounting method. -148°F 65 32°F • Change the mounting method 9.3 50 7.8 7.0 #12 PSA 40 6.2 35 5.4 30 4.7 25 3.9 20 3.1 #6 RTV 15 1.6 -50°C 0°C 50°C 0.
Designing with Thermofoil Heaters Introduction Estimating power requirements Conducting experiments The total amount of power required for an application is the larger of two values: Heat transfer theory is complex. It’s usually best to prototype your system with actual heaters to observe behavior and finetune the design. Minco offers a variety of tools to help you: 1. Warm-up power + Heat lost during warm-up 2.
Custom Design Options Heater designs to perfectly fit your application Methods to derive the profiling pattern include: Integrating temperature sensors directly into the Thermofoil heater improves your thermal control while at the same time simplifying the end-use assembly operation. Get more information on page 12. Value-added services: Complete thermal sub-assembly can provide a turnkey solution for your application.
Custom Design Options Integrating sensors and thermal cut-outs. Sensors can be electrically connected via leadwires or flex circuitry. Temperature sensors Introduction Design Guide Integrating sensors into heaters simplifies your assembly operations by providing a gradient-free system with excellent temperature control. The sensor sits in a window of the heating element. It reacts to temperature changes in the component beneath the heater, yet remains close to the heating element itself.
Custom Design Options Value-added assemblies and complete thermal solutions. Clamped mica heaters Design Guide Introduction Mica heaters must be secured between rigid plates to prevent separation of layers. Minco can provide many styles of mica heater assemblies: bolted, riveted or welded, flat or curved. Factory bonded AP heaters eliminate clamping and provide optimum heat transfer to the heat sink.
Examples of Thermal Systems Introduction Description of Heat a tank containing 2 kg of chemiThermal System cal solution from 20°C to 50°C in 10 minutes. The space available for mounting the heater is 4" × 5" (102 x 127 mm). Input voltage is 120 VAC. Heat moving film in a thermal processor. A sheet of polyester film weighing 5 g must be brought from 25°C to 90°C every 2 seconds. The heater will measure 2" × 12" (51 x 305 mm) and will be mounted on a metal platen. Input voltage is 120 VAC.
Examples of Thermal Systems Watt density = W/effective area = 61/21.54 in² = 2.8 W/in² (0.4 W/cm²) Any type of heater mounting will handle the watt density. We recommend acrylic PSA for fast availability of prototypes. AWG 24 leadwire current rating is 7.5 A. Actual current is: I = 24/9.4 = 2.6 A (OK). A custom control circuit integrated into the system electronics will control the heater. The controller is designed for a 1000 Ω platinum RTD element input. Watt density = W/effective area = 800/109.
Polyimide Thermofoil™ Heaters Thin, flexible heating solutions from -200 to 200°C Introduction Overview Design Guide Polyimide (Kapton™) is a thin, semitransparent material with excellent dielectric strength. Polyimide Thermofoil™ heaters are ideal for applications with space and weight limitations, or where the heater will be exposed to vacuum, oil, or chemicals.
Polyimide Thermofoil™ Heaters Specifications Introduction Temperature range: -200 to 200°C (-328 to 392°F). Upper limit with 0.003” (0.08 mm) foil backing is 150°C (302°F). Material: .0.002” Polyimide/0.001” FEP, (0.05/0.03 mm). Design Guide Resistance tolerance: ±10% or ±0.5 Ω, whichever is greater. Dielectric strength: 1000 VRMS. Minimum bend radius: 0.030” (0.8 mm). Polyimide Heaters Leadwire: Red PTFE insulated, stranded. Silicone Rubber Heaters (foil) Current capacity (based on 100°C max.
Silicone Rubber Thermofoil™ Heaters Rugged and flexible to 235°C Overview Introduction Silicone rubber is a rugged, flexible elastomer material with excellent temperature properties. It is most suited to larger heaters and industrial applications.
Standard Polyimide and Rubber Heaters Introduction Minco has invested in the design time and fabrication tooling so you can jump immediately to your prototyping efforts. The following table outlines the specifications of previously designed polyimide and silicone rubber Thermofoil™ heaters. Specification options Technical Specifications on pages 16 (polyimide) & 20 (rubber).
Wire-wound Rubber Heaters Custom options Introduction • Custom shapes and sizes to 22" × 90" (560 × 2285 mm) • Custom resistance to 200 Ω/in² (31 Ω/cm²) • Integral thermostats • RoHS compliance Design Guide • Contact Access: Minco Sales and Support for custom design assistance Temperature range: -45 to 235°C (-50 to 455°F). With UL component recognition: -45 to 220°C (-50 to 428°F). These silicone rubber heaters have a wire-wound element and are economical in large sizes.
Mica Thermofoil™ Heaters High watt density and temperature range Introduction Design Guide Polyimide Heaters Silicone Rubber Heaters (foil) Standard Polyimide & Rubber Overview Custom options Mica Thermofoil™ heaters consist of an etched foil element sandwiched between layers of mica. Installed by clamping to heat sinks, mica heaters provide the ultimate temperature and wattage capability for fast warmup.
Mica Thermofoil™ Heaters Current capacity (based on 100°C max. ambient temp.): AWG 22 - 8.0 A AWG 20 - 9.0 A AWG 18 - 11.0 A 932°F 1112°F 18.6 HEATER: 110 752°F MOUNTING METHOD: Clamped 17.1 15.5 100 12.4 70 10.9 60 9.3 50 7.8 6.2 40 0.020“ (0.5mm) Mica 30 4.7 20 3.1 10 1.6 0 0.0 -200°C -100°C 0°C 100°C 200°C 300°C 400°C 500°C 600°C Example: At 300°C, the maximum power of a 0.010" mica heater is 70 W/in² (10.9 W/cm² ). Backing plates Backing plates are 0.0625" (1.
Thermal-Clear™ Transparent Heaters Overview Introduction Featuring a micro-thin wire heating element laid in a pattern between optical grade polyester sheets, Thermal-Clear™ heaters provide reliable heat without blocking light.
Thermal-Clear™ Transparent Heaters Introduction Specifications Heaterstat™ Sensorless Temperature Controller Temperature range: -55 to 120°C (-67 to 248°F). Any Thermal-Clear heater will work with the CT198 Heaterstat™ Sensorless Temperature Controller, which directly regulates element temperature without requiring a separate sensor. See the "Sensors and Controllers" section for full specifications and compatibility. Insulation: Optical grade polyester is standard.
All-Polyimide (AP) Heaters Flexible heaters provide uniform heat transfer to 260°C (500°F) Overview Introduction AP heaters are a high performance alternative to Minco’s standard polyimide heaters, allowing higher temperatures and watt densities. Minco's unique ability to manufacture these heaters has prompted success in many high-temperature applications worldwide. Design Guide AP heaters must be factory mounted or clamped to heat sinks, and are only available as custom designs.
Temperature Sensors Fast response and easy installation Introduction Minco is a leading manufacturer of temperature sensors. We have hundreds of common model configurations in stock for immediate shipment. Below is a selection of popular sensors for use with our heaters and controllers. Thermal-Ribbon™ RTDs, Thermocouples and Thermistors Design Guide Flexible Thermal-Ribbons mount easily to surfaces, alongside heaters or on top of them. All are available with PSA (pressure sensitive adhesive).
Temperature Controllers If powered without regulation, a heater will rise in temperature until heat losses (increasing with temperature) equal heat input. This may be acceptable in rare situations, but normally is avoided because the equilibrium temperature is highly unpredictable. Desired operating temperature Design Guide In most cases the heater temperature needs to be controlled. This allows the heater to ramp up to setpoint faster without fear of overshooting and burning out the heater.
Heaterstat™ Sensorless DC Controller No separate sensor or thermostat required Leadwire version Introduction PCB mount Overview The Heaterstat takes temperature readings from heater models with a high temperature coefficient. You get accurate, efficient electronic control at prices comparable to thermostats.
Heaterstat™ Sensorless DC Controller Controller supply current: Output ON: 3 mA max. Output OFF: 2 mA max; 1 mA typical at 10 VDC. Connections: Three pins on 0.1" centers or AWG 22 wires. Ambient temperature: Operating: -40 to 70°C (-40 to 158°F). Storage: -55 to 85°C (-67 to 185°F). Nominal heater current: 0.05 to 4 amps. See ranges below. Higher current possible with special models. Physical: Epoxy sealed for moisture resistance.
Heaterstat™ Sensorless DC Controller Standard models Specification options Introduction One second scan rate. CT198-1019 Model number CT198 = Heaterstat (nominal setpoint) CT698 = Heaterstat matched to heater R Setpoint calibration code R = Nominal heater resistance (CT198) T = Heaterstat/heater matched set (CT698) 365 Initial calibration setpoint Setpoint calibration code = R: Nominal heater resistance at set point temperature (in ohms).* Must be within allowable range for specified model.
Design considerations Evaluation kits Minco will be pleased to provide assistance with any of the design steps below. Test the concept and performance of Heaterstats before investing in a custom design. Each includes a controller and matching heater. You just supply electric power. • Use the proper amount of heat. Try to size the heater to run at least 50% of the time in normal operation and at no more than 5 W/in² (0.78 W/cm²). • Maximize contact between the heater and heat sink.
CT325 Miniature DC Temperature Controller Tight control in a small package Introduction Overview Design Guide Polyimide Heaters Silicone Rubber Heaters (foil) The CT325 Miniature DC Temperature Controller is designed for use with Minco Thermofoil™ heaters and RTD or thermistor sensors. It offers inexpensive on/off temperature control of your process or equipment with accuracy many times better than bimetal thermostats.
CT325 Miniature DC Temperature Controller Model number PD Sensor type from table below 1 Power supply: 1 = 4.75 to 10 VDC 2 = 7.5 to 60 VDC 1 2 3 4 5 6 7 DC + Power Supply – Design Guide RTD Temperature range: A = 25 to 75°C (thermistor only) C = 2 to 200°C (RTD only) Dead band: 1 1 = 0.
CT15 Temperature Controller & Alarm Compact 1/16 DIN size Introduction Design Guide Polyimide Heaters R CT15 Controller Silicone Rubber Heaters (foil) Standard Polyimide & Rubber Overview Specifications The CT15 is an easy to use controller with sophisticated PID control. It can also be a single or 2-stage alarm (using alarm feature plus control relay) to monitor motors and generators for overheating. Selectable inputs: RTD: 2 or 3-wire, Minco types PD or PE (100 Ω EN60751 platinum).
CT15 Temperature Controller & Alarm CT15 Model number Resolution: 1° or 0.1°, selectable. 1 Alarm: 0 = No 1 = Yes Line voltage stability: ±0.05% over supply voltage range. Supply voltage: 100 to 240 VAC nom., +10/-15%, 50 to 400 Hz, single phase; 132 to 240 VDC, nom., +10/-20%. 5 VA maximum. Note: Do not confuse controller power with heater power. The controller does not supply power to the heater, but only acts as a switch.
CT16A Temperature Controller Compact 1/16 DIN size Introduction Design Guide Polyimide Heaters Silicone Rubber Heaters (foil) CT16A Controller Standard Polyimide & Rubber Overview Rubber Heaters (wire-wound) This economical controller packs sophisticated PID control into a compact 1/16 DIN enclosure. A wide range of control modes, sensor input types, and relay or SSR outputs give versatile control of Thermofoil™ heaters and lets you easily connect to other electronics.
Cycle rate: 1 to 80 seconds. Setpoint range: Selectable from -212 to 2320°C (-350 to 4208°F), input dependent. Displays: Two, 4 digit, 7 segment, 0.3" high LEDs. Process Value red, Setpoint Value green. °C or °F. Control action: Reverse (usually heating) or Direct (usually cooling), selectable. Ramp/soak: (CT16A3 only) 16 separate ramp and soak times are adjustable in minutes or seconds from 0 to 9999.
CT16A Temperature Controller Dimensions shown in inches (mm) Introduction 1.89 (48) Accessories AC744: 1-10 A, 24 to 280 VAC SSR AC745: 1-25 A, 24 to 280 VAC SSR 1.89 (48) AC746: 1-50 A, 24 to 280 VAC SSR AC1009: 1-20 A, 0 to 100 VDC SSR Design Guide AC743: SSR heat sink for high current or ambient temperature 5.04 (128) Polyimide Heaters 1.76 (44.7) AC996 R/C Snubber: Highly recommended to prolong relay contact life if using the mechanical relay or SSR output to drive a relay or solenoid.
Heater Accessories TH200 Specifications Stock models: TH100 creep action, 120 VAC maximum. TH200 snap action, 240 VAC maximum. Setpoint tolerance: ±5°C (±9°F). Contact configuration: Normally open (NO) above setpoint. Open/close differential: 5 to 10°C, typical. Introduction 0.93" (23.62 mm) Design Guide Max. thickness = 0.18" (4.
Frequently Asked Questions What is the correct voltage for this heater? Introduction Design Guide Standard heaters are specified by resistance, not voltage. This lets you operate them at different power levels. In selecting a heater model you should consider the size, resistance, operating temperature, total wattage and watt density (watts/in² or watts/cm²) for your application. The watt density rather than the total wattage determines the maximum applied voltage.
Heat sink: The body to which a heater is affixed. Heat transfer: The transfer of thermal energy between bodies of different temperature. Heaterstat™: A Minco temperature controller that uses the heating element as a temperature feedback sensor. Temperature above setpoint: Sensing pulses only Temperature below setpoint: Each pulse stays on until heat On Output Design Guide Off Scan rate = Preset off time between pulses (0.
Glossary Introduction Design Guide Polyimide Heaters Silicone Rubber Heaters (foil) Standard Polyimide & Rubber Rubber Heaters (wire-wound) Mica Heaters Thermal-Clear All-Polyimide Heaters Heaters Proportional band: A region around the setpoint where the output is proportional to the process’s distance from that setpoint. For example, 100% heater power during warmup is proportioned to 75%, then 50%, then 25% as temperature nears setpoint.
Industry Specifications for Heaters UL: Underwriters Laboratories Introduction Minco's Quality Assurance system has been audited and certified compliant with these internationally recognized standards. QPL (Qualified Producer List). Astrium (consortium of British, French, German and Spanish manufacturers of aerospace and satellite equipment) United States and Canada: Specification C22.
Next Steps Minco welcomes the opportunity to help you design and manufacture a heating solution that meets and exceeds your expectations. That is why we have established a variety of communication channels so that we may encourage meaningful exchange and dialog. Call Access: Minco Sales and Support – Americas - 763.571.
Worldwide Headquarters 7300 Commerce Lane Minneapolis, MN 55432 USA Tel: 1.763.571.3121 Fax: 1.763.571.0927 sales@minco.com www.minco.com European Headquarters Usine et Service Commercial, Z.I.
