Thick Film Heating Elements

Thick Film Heating Elements are high-efficiency heating components made by printing conductive, heating, and insulating materials onto substrates such as stainless steel (SUS304 or SUS430), ceramics (Alumina or Aluminum Nitride), or flexible materials (Polyimide or PET), featuring fast thermal response, uniform temperature distribution, high mechanical strength, and resistance to thermal cycling, while their flexibility allows integration into complex shapes, offering designers low energy consumption, long lifespan, and multifunctional customized solutions.

Thick Film Heating Elements utilizing advanced thick film technology, are composed of multiple precisely engineered layers, including a dielectric layer, conductive layer, resistor layer, and insulating layer. The printing process allows for meticulous control over the resistor's thickness and width, facilitating precise regulation of key parameters such as heater resistance, power output (wattage), power density, and the uniformity of the heated surface area.

Thick Film Heating Elements are highly versatile and widely used in industries such as automotive, aerospace, electronics, medical devices, and renewable energy. Their precise heat distribution and compact design make them ideal for applications like temperature sensors, thermal management and solar thermal systems. With excellent durability, energy efficiency, and uniform temperature control, these elements provide reliable and cost-effective heating solutions across various demanding environments.

Substrate Features of Thick Film Heating Elements :

The choice of substrate for Thick Film Heating Elements depends on the specific requirements of the application. Here are some common substrate features used in Thick Film Heating Elements:

1, Stainless Steel (SUS304 or SUS430): Stainless steel substrates offer excellent corrosion resistance and high mechanical strength. They are commonly used in applications where durability and resistance to harsh environments are important.

2, Ceramic (Alumina or Aluminum Nitride): Ceramic substrates provide good thermal conductivity, electrical insulation, and high-temperature resistance. They are suitable for applications that require efficient heat transfer and high operating temperatures.

3, Flexible Base (Polyimide or PET): Flexible base materials like Polyimide or PET allow for bending and conforming to curved surfaces. They are often used in applications where flexibility and thinness are required, such as in wearable devices or curved heating surfaces.

4, Mica: Mica substrates offer excellent electrical insulation, high-temperature resistance, and good thermal conductivity. They are often used in applications that require high power density, such as in industrial heating or high-temperature furnaces. Mica substrates can also provide good mechanical stability and resistance to thermal shock, making them suitable for harsh environments. However, mica substrates may not be suitable for applications that require flexibility or conformability.

The choice of substrate depends on factors such as the desired thermal properties, mechanical strength, electrical insulation, and the specific application requirements. By selecting the appropriate substrate, Thick Film Heating Elements can be optimized for performance, reliability, and compatibility with the intended application.

Please refer to Thick Film Technology for more informations.

Main Product Types of Thick Film Heating Elements :

1, Ceramic-Thick Film Heating Elements :

Ceramic Thick Film Heating Elements are used when high temperatures are required, fast responses or temperature gradients are needed or products need to be heated in certain areas in a targeted way. With typical operating temperatures range from 300°C to 700°C producing infrared wavelengths ideal for caramelization of breads, warming and heating of foods, curing of coatings, and softening or welding of plastics.

Ceramic Thick Film Heating Elements are capable of transferring up to 92% of their input as radiant energy, maximum efficiency is reached when the emitted wavelength and the absorption spectrum of the material to be heated are optimized, Which is with High compression strength, hardness and wear resistance. It can facilitate high heat resistance and high thermal conductivity applications.

The majority of radiant ceramic thick film heating elements are thought to be more successful at producing heat where it’s needed than electric or oil-filled radiators. Radiant thick film ceramic heaters utilize electricity to heat the ceramic plate and do not employ a fan to move air in or out. Rather than radiating heat into objects in its path, the thick film ceramic heater absorbs it through direct contact with them.The heat in radiant heaters does not spread uniformly throughout the space, as it does with convection heaters, but it lasts for a longer period because it is retained within objects rather than in the air.

2, Stainless Steel-Thick Film Heating Elements :

Stainless Steel Thick Film Heating Elements are suitable for applications with surface loads up to 50 W/cm², and appropriate heat dissipation by water or another medium is required. This type of heaters are capable for applications that need high temperatures of up to 450 °C, Also applied to complex shapes to generate targeted heat.

Stainless Steel Thick Film Heating Elements normally used insulated chrome steel or stainless steel as the base material. The high mechanical stability allows molding of the metal base as well as using insert technology for combination with plastic materials. The structure of appliances with stainless steel-thick film heating elements will be relatively easier, more compact and exquisite, Temperature rise faster and more stable with lower heat capacity, also more moldability and mechanical stability.

The main thing to stress here is that dielectric layer separates between the stainless steel substrate and the printed conductor traces, The dielectric materials are generally using enamel, polymers, or epoxies resin based all to be not conductive. This layer is particularly necessary if the substrate is metallic as stainless steel, The metal substrate must be electrically insulated from the conductor traces of conductor material, The dielectric layer restrict leak current and ensure the electric integrity of the heater.

3, Flexible Heating Elements (Polyimide Heater and Polyester Heater) :

Flexible Heating Element is a thin, lightweight organic polyimide, silicone and polyester (PET) film heater designed for precise heating requirements ranging from -319 to 392°F (-195 to 200°C) ,which provides excellent tensile strength, tear resistance and dimensional stability. Flexible Heaters include Polyimide Heaters (PI Heaters), Polyester Heaters (PET Heaters) and Silicone Heaters.

Most of the flexible heating elements are made of polyimide for increased flexibility for curved surfaces and chemical resistivity. The thin nature of these flexible heating element makes them ideal for tight spaces and good for applications such as hot plates, airplanes, storage tanks, beakers, trays, drying chambers and more. Flexible Heater also is ideal for applications requiring low outgassing in a vacuum, fungus and chemicals.

Flexible Heating Elements can introduce new design versatility to creatively solve a variety of thermal management challenges from more consistent environment stabilization to faster thermal cycling. With PANDA-PCB's Flexible Heating elements you can use your imagination to apply heat to the most complex shapes conceivable, and do it with efficiency, dependability and value.The Flexible Heater units can be designed into three-dimensional shapes and conformed to the most complex geometries.

4, Mica-Thick Film Heating Elements :

Mica Thick Film Heating Elements utilize mica as an insulator and a thick film as the heat-producing component. Mica, a naturally occurring mineral, is extensively used in the electronics industry due to its exceptional electrical insulation properties. It retains these properties even at high temperatures, making it an ideal material for heating elements. The thick film is a layer of resistive material applied to the mica substrate, the thickness of this layer can be controlled to achieve the desired heating performance.

The production of a mica-thick film heating element involves the application of a thick film onto the mica substrate, followed by a high-temperature heating process. This procedure results in the thick film adhering to the mica, thus forming a durable and efficient heating element.

Mica Thick Film Heating Elements find usage in a range of applications, from home appliances such as hair dryers and space heaters to industrial equipment and automotive components. Their popularity stems from their rapid heating capability, high thermal efficiency, and superior electrical insulation – all significant advantages offered by mica heaters.

Main Advantages of Thick Film Heaing Elements :

1, Without Electrical Complication :
The printing patterns can reduce potential electrical inductance and capacitance inherent in wound resistance wires.

2, Long Life :
Service life of Thick Film Heating Elements can be very long if the application conditions can be met according to instruction of operations. Thick film heating elements tend to last longer if the temperature is kept below its designed maximum temperature rating.

3, Heating Patterns :
Thick Film Heating Elements are made with screen printing process for heating traces, which can be tailored to applications to deliver even heat for thermal uniformity across a surface, or different power densities in different areas.

4, Low Profile :
The most distinguishing character of Thick Film Heating Elements its low profile and can made with a small dimensions, Thick film heating element minimize the space requirements and is ideally suitable for thermal coupling to flat heat sinks, printed circuit boards and bulk heads etc.

5, High Operating Temperature :
Ceramic-Thick Film Heating Elements have maximum operating temperature up to 1800°F.

6, Corrosion Resistant :
Ceramic Thick Film Heating Elements have excellent corrosion resistance and perform well under corrosive conditions where acid and alkali solutions exist. For Aluminum-Thick Film Heating Elements, after forming a layer of oxidation by gaseous acids present in the air, which serves a corrosion-resistant layer.

7, Light Weight :
The thick film heating elementis thin and light weight, and excellent for applications which need rapid heating and uniform temperature. The low mass also lowers energy consumption and boost performances.

8, Low Thermal Mass or Heat Capacity :
The low thermal mass is ideal for rapid thermal response or fast temperature cycling. which Having a low heat capacity, the temperature can be increased quickly by using low amount of energy.

9, Maximum Heat Transfer :
Due to the direct surface contact, a Thick Film Heating Element ensures efficient heat transfer via conduction through thermally stable substrates and precise resistance trace patterns.

10, Odd Form Factors :
Unlimited unusual heater shapes and geometry to fit target areas for unique heating patterns. The intention is to fit custom profile or area.

Main Appilcations of Thick Film Heating Elements :

Thick Film Heating Elements are widely applied in electric water heater, electric coffee pot, electric kettle, steam iron, instant water machine, steam generator etc. Please check the main applications as followings :

1, Industrial : Electronic enclosures, plastic fabrications, water heating, packaging lines, and hot plates.

2, Food and Beverage Equipments : Hot food displays, warming trays, storage warming, holding cabinets, brewing temperature maintenance, and portable food delivery.

3, Aviation and Transportation : Instrumentation, oil and battery heating, personal comfort, deicers, over the road truck and railcar freeze protection.

4, Automotive : Cabinet comfort heating, battery warming, fuel cell temperature maintenance, motor heating, mirror defogging, steering wheel and seats heating, door handle de-freezing, and coolant heaters.

5, Food Service : Warming holding cabinets, fryer systems, display shelves, prep stations,grilling platters, heated dishware, and appliances.

6, Medical and Life Sciences : Instrument warming, MRI equipment, temperature therapy, dialysis, CPAP, surgical devices, vessel sealer, DNA analysis and testing, blood diagnostics, blood and fluid warming, and sterilization.

7, Analytical Instruments and Research Institutions : Imaging equipment, thermal analysis, chromatography, spectrometers, separation and membrane sciences.

8, Semiconductor : High temperature burn-in and testing equipment, water heating, wafer chuck heaters.

9, Security : Explosives detection, alcohol detection, chemical detection, and cameras lens defogging.

10, Printing : Thermal printers, 3D-Printers, card printers, laser printers, commercial and industrial printers.

11, Health and Beauty Appliances : Skin spa and facial steamer, heating pads and blankets, personal hair styling and drying tools, heating body and foot massager.

Manufacturing Processes for Thick Film Heating Elements :

Thick Film Heating Elements are essential components utilized in various heating applications, ranging from industrial processes to consumer appliances. These elements are manufactured through a series of specialized processes designed to ensure optimal performance and reliability. Below is an overview of the manufacturing processes involved in producing thick film heating elements:

1, Substrate Preparation:
● The manufacturing process begins with the selection of a suitable substrate material, often ceramic or stainless steel, which provides the structural support for the heating element.
● The substrate undergoes thorough cleaning and surface preparation to remove any contaminants and promote adhesion of subsequent layers.

2, Paste Formulation:
● The conductive paste, composed of finely ground metal particles dispersed in a binder material, is formulated to achieve the desired electrical conductivity and temperature stability.
● Various additives may be incorporated into the paste to enhance properties such as adhesion, resistivity, and thermal conductivity.

3, Screen Printing:
● Screen printing is the primary method used to print the conductive paste onto the substrate.
● A stencil with the desired pattern is placed over the substrate, and the conductive paste is forced through the openings onto the surface using a squeegee.

4, Drying and Curing:
● After the conductive paste is printed, the substrate undergoes drying to remove the solvent from the binder.
● Curing follows drying, where the substrate is heated to a specific temperature to cross-link the binder and form a stable conductive layer.

5, Insulation and Dielectric Layers:
● Insulation and dielectric layers are applied over the conductive traces to prevent electrical short circuits and enhance thermal efficiency.
● Typically printed using similar screen printing techniques, these layers undergo drying and curing processes.
● The protective layer offers electrical insulation, preventing short circuits and ensuring the safe operation of the heating element. It isolates the conductive and resistive layers from external electrical contact.
● The insulating layer should possess low thermal conductivity to minimize heat loss from the heating element, thus improving overall efficiency and effectiveness in the heating process.
● Apart from its electrical and thermal properties, the insulating layer also provides mechanical protection, reinforcing the heating element against physical stress, such as bending or impact.

6, Firing:
● Firing, or called sintering, is a critical step in the manufacturing where the substrate with printed layers is heated to high temperatures in a controlled atmosphere.
● This process facilitates the bonding of the metal particles and promotes diffusion, resulting in a dense and durable heating element.

7, Finishing:
● Once the firing process is complete, the heating element undergoes final finishing processes, including trimming, machining, and surface treatment, to achieve the desired dimensions and appearance.
● Quality control measures are implemented throughout the manufacturing process to ensure uniformity and adherence to specifications.

8, Testing and Quality Assurance:
● The finished heating elements undergo rigorous testing to verify electrical performance, thermal uniformity, and durability.
● Quality assurance protocols are in place to identify and rectify any defects or inconsistencies before the products are released for distribution.

The manufacturing processes for Thick Film Heating Elements involve substrate preparation, paste formulation, screen printing, drying and curing, insulation and dielectric layer printing, firing, finishing, and rigorous testing. These processes are carefully controlled and optimized to produce high-quality heating elements suitable for a wide range of applications.

Why Deed to Customize Thick Film Heating Elements ?

Custom Thick Film Heating Elements is essential in various applications and industries, primarily due to their unique properties and advantages. Here are some reasons why deed to customize thick film elements:

● Specific Application Needs: Every application has unique requirements in terms of size, shape, power output, and thermal efficiency. Customization allows for the creation of heating elements that are tailored to meet these specific needs.

● Optimized Performance: By designing elements to fit the exact specifications of the application, it's possible to optimize the performance. This can lead to better heat distribution, faster response times, and more consistent operation.

● Increased Efficiency: Custom thick film heating elements can be more energy-efficient. By precisely controlling the size and resistance of the element, less energy is wasted, leading to lower operating costs and reduced environmental impact.

● Reliability and Durability: Custom thick film heating elements can be engineered to withstand the rigors of their intended environment. This can include resistance to high temperatures, corrosive substances, or mechanical stress, thereby increasing the lifespan of the product.

● Design Flexibility: Thick film heating element allows for a high degree of design flexibility. This means that heating elements can be created in almost any shape or form factor, allowing for seamless integration into a wide range of products.

● Cost-Effectiveness: While there may be an initial investment in the design and development of a Custom Thick Film Heating Element, the long-term benefits often include reduced material waste, lower energy consumption, and fewer maintenance issues, which can lead to cost savings.

● Innovation and Competitive Edge: Customization enables companies to innovate and differentiate their products from competitors. It can be a key factor in developing proprietary technologies that are difficult for others to replicate.

● Regulatory Compliance: In some industries, there are strict regulations regarding the performance and safety of heating elements. Customization ensures that these elements meet all necessary standards and certifications.

● Scalability: As production needs grow, Custom thick film heating elements can be scaled up or down to match the demands without compromising on quality or performance.

● Integration with Smart Technologies: With the advent of the Internet of Things (IoT), there's an increasing need for heating elements that can interface with smart systems. Customization allows for the integration of sensors and controls that enable remote monitoring and advanced functionality.

Why Choose PANDA PCB For Thick Film Heating Elements ?

PANDA PCB Group - Thick Film Solution, a company dedicated to Thick Film Heating Elements, boasts a solid 20-years track record in product research, development, and manufacturing. Choose PANDA PCB for your Thick Film Heating Element needs and feel the difference that a dedicated and experienced partner can bring. Trust in our expertise, innovation, quality, and customer-centric approach.

● Unparalleled Expertise and Experience: Our 20-years journey in the Thick Film Heating Elements industry has armed us with a wealth of knowledge and honed our skills, enabling us to deliver top-notch, reliable products. We've mastered the complexities of the technology, positioning us to offer expert guidance to our clients.

● Cutting-Edge Innovation: At PANDA PCB, we're driven by the quest for continuous improvement. Our research and development team ceaselessly breaks new ground to devise innovative solutions that keep pace with our clients' evolving needs.

● Uncompromising Quality Assurance: We uphold rigorous quality control standards to ensure that our thick film element products not only meet but surpass industry benchmarks. Our Thick Film Heating Elements stand as a testament to our steadfast commitment to high quality.

● Customer-First Approach: We place immense value on our customers and go the extra mile to provide them with exceptional service. Our team is always on hand to address any questions or concerns you may have.

Design Guidelines of Thick Film Heating Elements :

We compiled a Thick Film Heating Elements-Design Guidelines as attached for you to download, It is to better support our customers' needs in designing and applying Thick Film Heating Elements, This guide covers detailed information on product solutions, engineering design specifications, material properties, available manufacturing processes, and more.

We hope that this guide will assist customers in standardizing their design process while ensuring the manufacturability of the design data, ultimately improving product reliability and production efficiency. Customers are encouraged to refer to the guide when designing Thick Film Heating Elements to ensure adherence to best practices.

Materials Introduction of Thick Film Heating Elements :

Substrates :

Alumina (Al2O3)

Aluminum Nitride (AlN)

Beryllium Oxide (BeO)

Zirconium Dioxide (ZrO2)

Aluminum (Al)

Stainless Steel

Max Application Temperature :

662 - 1832

1832

2300

2432

302

1202

Max Power Density (W/in²):

75

1010

250

300

400

200

Max Ramp Up Speed (°F/sec):

122

572

400

350

302

315

Thermal Conductivity (W/mK):

20-35

180-220

200-300

2.0-5.0

173

15

Density (g/cm³):

3.75

3.26

2.8

5.9

2.7

7.8

Dielectric Loss:

0.0001 - 0.001

0.0001 - 0.0005

0.0001 - 0.0002

0.0005 - 0.001

/

/

Dielectric Constant:

9.4 - 10.2

8.5 - 9.0

6.0 - 7.0

25 - 30

/

/

CTE, ppm/ºC:

6.0 - 8.0

4.0 - 5.0

7.0 - 9.0

10.0 - 11.0

24.0

5.8

Substrate Thickness (mm):

0.25, 0.38, 0.50, 0.635, 0.80,1.0, 1.25, 1.5, 2.0mm, Customizable

0.25, 0.38, 0.50, 0.635, 0.80,1.0, 1.25, 1.5, 2.0mm, Customizable

0.25, 0.38, 0.50, 0.635, 0.80,1.0, 1.25, 1.5, 2.0mm, Customizable

0.25, 0.38, 0.50, 0.635, 0.80,1.0, 1.25, 1.5, 2.0mm, Customizable

0.25, 0.38, 0.50, 0.635, 0.80,1.0, 1.25, 1.5, 2.0mm, Customizable

0.6, 1.0, 1.2, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0, 6.0, 8.0, 10.0mm, Customizable

Typical Max. Dimension (inch):

6 x 12

5 x 11

6 x 6

4 x 4

12 x 24

20 x 24

Theoretical Total Wattage (W):

5400

55000

15000

20000

115200

57600

1, Dielectric layer of Thick Film Heating Elements refers to a specific component or coating within the structure of the heating element. It serves as an insulating layer that separates the conductive elements from the surrounding environment or other components.

2, In thick film heating elements, the dielectric layer is typically applied on top of the conductive layer. It acts as a barrier, preventing direct electrical contact between the conductive material and any adjacent layers or surfaces. This insulation is crucial to ensure safe operation and prevent short circuits.

3, The dielectric layer also plays a role in thermal management. It helps minimize heat loss from the heating element by reducing thermal conductivity. This ensures that most of the generated heat is directed towards the intended target, improving energy efficiency.

4, The choice of materials for the dielectric layer depends on various factors such as the desired electrical properties, thermal stability, compatibility with manufacturing processes, and environmental resistance.

Conductive layer is a key component of Thick Film Heating Elements, working in conjunction with the dielectric layer to generate heat. Here are some important points about the conductive layer:

1, Material Composition: The conductive layer is typically composed of a mixture of metal powders, such as silver, palladium, or platinum, suspended in a glass or ceramic binder. These metal powders provide the electrical conductivity necessary for heat generation.

2, Screen Printing: The conductive layer is applied to the substrate using screen printing techniques. A specially formulated paste containing the metal powders and binder is printed onto the substrate in a desired pattern or shape.

3, Electrical Conductivity: The conductive layer must exhibit high electrical conductivity to efficiently convert electrical energy into heat. This allows for effective power transfer and uniform heat distribution across the surface of the heating element.

4, Thickness Control: The thickness of the conductive layer can be adjusted during the screen printing process to achieve the desired resistance and power output characteristics. Thicker layers result in lower resistance and higher power output, while thinner layers have the opposite effect.

5, Adhesion: The conductive layer must adhere well to the substrate and other layers in the thick film heating element structure. Good adhesion ensures mechanical stability and prevents delamination or cracking during operation.

6, Thermal Stability: The conductive layer should maintain its electrical and physical properties over a wide range of operating temperatures. It should resist oxidation, sintering, or other forms of degradation that may affect its conductivity and performance.

7, Compatibility: The conductive paste used for the layer should be compatible with the substrate material and the subsequent processing steps, such as firing or curing. This ensures proper integration and functionality of the thick film heating element.

Resistive layer is another important component of Thick Film Heating Elements. It is responsible for generating heat when an electrical current passes through it. Here are some key points about the resistive layer:

1, Material Composition: The resistive layer is typically made of a mixture of metal oxides, such as ruthenium oxide (RuO2), and glass or ceramic binders. The metal oxides provide the resistive properties necessary for heat generation.

2, Screen Printing: Similar to the conductive layer, the resistive layer is applied to the substrate using screen printing techniques. The paste containing the metal oxides and binder is printed onto the substrate in a desired pattern or shape.

3, Resistivity: The resistive layer is designed to have a specific resistivity, which determines the amount of heat generated when an electrical current passes through it. The resistivity can be adjusted by varying the composition and thickness of the resistive layer.

4, Power Output Control: By controlling the resistivity and dimensions of the resistive layer, the power output of the thick film heating element can be tailored to meet specific requirements. Thicker or more resistive layers result in higher power output, while thinner or less resistive layers produce lower power output.

5, Temperature Coefficient of Resistance (TCR): The resistive layer's TCR indicates how its resistance changes with temperature. It is essential to select materials with appropriate TCR values to ensure stable and predictable performance across different operating temperatures.

6, Adhesion and Stability: The resistive layer must adhere well to the substrate and other layers in the thick film heating element structure. It should also maintain its resistive properties over time, resisting degradation or changes in performance due to factors like thermal cycling or exposure to high temperatures.

Insulating layer is an important material of Thick Film Heating Elements that serves to protect the underlying layers and enhance the overall performance and durability of the heating element. Commonly used non-metallic materials for protective coatings include overglazes (Glass-Glaze), enamel, polymers, and epoxies,depending on application conditions and environment. The insulating-protective layer for custom heating element is printed or coated continuously to cover the heater assembly as the sheath of the heating element. Here are some key points about the protective layer:

1, Purpose: The insulating layer acts as a barrier between the environment and the underlying layers of the heating element. It helps to prevent moisture, chemicals, and other contaminants from reaching the sensitive components, such as the conductive and resistive layers.

2, Material Composition: The insulating layer is typically composed of a glass or ceramic material that is resistant to corrosion, oxidation, and chemical attack. It may also contain additives to improve its mechanical strength and thermal stability.

3, Application: The insulating layer is applied over the conductive and resistive layers using screen printing techniques. The paste or ink containing the protective material is printed onto the substrate and then fired or cured to form a solid and protective coating.

4, Insulation: The protective layer provides electrical insulation, preventing short circuits and ensuring safe operation of the heating element. It isolates the conductive and resistive layers from external electrical contact.

5, Thermal Conductivity: The insulating layer should have a low thermal conductivity to minimize heat loss from the heating element. This helps to improve the overall efficiency and effectiveness of the heating process.

6, Mechanical Protection: In addition to its electrical and thermal properties, the insulating layer also offers mechanical protection. It helps to strengthen the heating element, making it more resistant to physical stress, such as bending or impact.