Multiple parallel circuit thick film electric heating elements and electric heating equipment

Abstract

This utility model discloses a multi-parallel circuit thick-film electrothermal element and an electrothermal device. The multi-parallel circuit thick-film electrothermal element includes a substrate, heating strips, a first wire, and a second wire. The heating strips extend along a first direction, and multiple heating strips are arranged parallel to each other and spaced apart. The first wires extend along a second direction, and multiple first wires are arranged spaced apart along the first direction, with each first wire electrically connected to multiple heating strips. The multiple first wires and multiple second wires are staggered along the first direction, so that each heating strip is divided into multiple heating blocks.

Description

Technical Field

[0001] This utility model relates to the field of thick film heating technology, and in particular to a multi-parallel circuit thick film electric heating element and electric heating device. Background Technology

[0002] Thick-film heating elements, as an emerging type of heating technology, are increasingly being used in everyday household appliances. Their traditional circuit design typically involves printing a single, continuous thick-film circuit on a substrate, using a winding, meandering path to increase the heating area. However, this design often results in overly dense circuitry, leading to uneven heat distribution and even circuit meltdown due to localized overheating. Once such a failure occurs, the entire heating device malfunctions, significantly shortening its lifespan. Utility Model Content

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, this invention proposes a multi-parallel circuit thick-film electric heating element and electric heating device.

[0004] In a first aspect, embodiments of the present invention provide a multi-parallel circuit thick-film heating element, the multi-parallel circuit thick-film heating element comprising:

[0005] Matrix;

[0006] A heating strip is disposed on the substrate, the heating strip extends along a first direction, and a plurality of heating strips are arranged parallel to each other and spaced apart;

[0007] A first wire extends along a second direction, a plurality of first wires are arranged at intervals along the first direction, and each first wire is electrically connected to a plurality of heating strips. The first direction intersects the second direction, and one end of the plurality of first wires is used to connect to the positive terminal of the power supply.

[0008] The second wire extends along the second direction, and a plurality of the second wires are arranged at intervals along the first direction, and each of the second wires is electrically connected to a plurality of the heating strips, and one end of the plurality of the second wires is used to connect to the negative terminal of the power supply;

[0009] Multiple first wires and multiple second wires are staggered along a first direction, so that each heating strip is divided into multiple heating blocks.

[0010] According to some embodiments of the present invention, the width of the heating strip is greater than the width of the first wire and the second wire.

[0011] According to some embodiments of the present invention, the first direction and the second direction are perpendicular to each other to form a grid-like circuit layout.

[0012] According to some embodiments of the present invention, among the plurality of heating blocks of the heating strip, at least two heating blocks have unequal widths.

[0013] According to some embodiments of the present invention, the multi-parallel circuit thick film electric heating element further includes a first insulating layer, which is located between the substrate and the heating strip. The first wire and the second wire are both disposed on the side of the first insulating layer away from the substrate. The side of the first insulating layer away from the substrate is provided with a first electrode and a second electrode. One end of the plurality of first wires is connected to the first electrode, and one end of the plurality of second wires is connected to the second electrode.

[0014] According to some embodiments of the present invention, the multi-parallel circuit thick film heating element further includes a second insulating layer, which covers the side of the heating strip away from the first insulating layer. The second insulating layer covers both the first wire and the second wire and exposes the first electrode and the second electrode. The first electrode is used to connect to the positive terminal of the power supply, and the second electrode is used to connect to the negative terminal of the power supply.

[0015] According to some embodiments of the present invention, the substrate is a metal substrate or a non-metal substrate.

[0016] According to some embodiments of this utility model, the substrate is aluminum, carbon steel, cast iron, stainless steel, copper, or a copper alloy.

[0017] According to some embodiments of the present invention, the substrate is in the form of a sheet or a tube.

[0018] The multi-parallel circuit thick-film electric heating element according to the embodiments of this utility model has at least the following technical effects:

[0019] 1. After being powered on, the current moves along the first wire. After passing through the heating strip, the current is split and passes through multiple heating blocks. After being powered on, the multiple heating blocks of the heating strip generate heat and thus heat the substrate. The current then merges and enters the second wire.

[0020] 2. The first wire, the second wire, and the heating strip form a grid-like parallel circuit layout. When one of the heating blocks melts, the current can still flow through other parallel paths. The entire multi-parallel circuit thick film heating element will not fail immediately, greatly improving reliability and service life.

[0021] 3. The current is evenly distributed to the entire heating area through multiple paths, improving heat distribution and avoiding local overheating.

[0022] Secondly, this utility model embodiment also provides an electric heating device, including a multi-parallel circuit thick film electric heating element according to the first aspect embodiment of this utility model described above.

[0023] The electric heating device according to the embodiments of this utility model has at least the following technical effects: The electric heating device uses the multi-parallel circuit thick-film electric heating element. After the first wire and the second wire are energized, the current moves along the first wire. After passing through the heating strip, the current is split and passes through multiple heating blocks. The multiple heating blocks of the heating strip are energized and generate heat, thereby heating the substrate. The current then merges into the second wire. During this process, the first wire, the second wire, and the heating strip form a grid-like parallel circuit layout. When one heating block melts, the current can still flow through other parallel paths. The entire multi-parallel circuit thick-film electric heating element will not immediately fail, greatly improving reliability and service life. Moreover, the current is evenly distributed to the entire heating area through multiple paths, improving heat distribution and avoiding localized overheating.

[0024] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0025] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0026] Figure 1 This is a schematic diagram of the structure of a multi-parallel circuit thick film electric heating element according to some embodiments of this utility model;

[0027] Figure 2 This is a partial structural schematic diagram of a multi-parallel circuit thick film electric heating element according to some embodiments of this utility model.

[0028] Icon labels:

[0029] 100 for the substrate; 110 for the heating strip; 120 for the heating block;

[0030] First wire 210; Second wire 220;

[0031] First insulating layer 310; Second insulating layer 320;

[0032] First electrode 410; second electrode 420. Detailed Implementation

[0033] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0034] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0035] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0036] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0037] The embodiments of this utility model will be further described below with reference to the accompanying drawings.

[0038] In this embodiment, the first direction is the front-to-back direction, and the second direction is the left-to-right direction.

[0039] According to some embodiments of this utility model, refer to Figure 1The multi-parallel circuit thick-film electrothermal element includes a substrate 100, heating strips 110, first wires 210, and second wires 220. The heating strips 110 cover the upper surface of the substrate 100 and extend along a first direction, i.e., along the front-to-back direction. Multiple heating strips 110 are parallel to each other and spaced apart. The first wires 210 extend along a second direction, and multiple first wires 210 are spaced apart along the first direction, with each first wire 210 electrically connected to multiple heating strips 110. The first and second directions intersect. The second wires 220 extend along the second direction, and multiple second wires 220 are spaced apart along the first direction, with each second wire 220 electrically connected to multiple heating strips 110. Both the first and second wires 210 extend along the left-to-right direction. The multiple first wires 210 and multiple second wires 220 are staggered along the first direction, causing each heating strip 110 to be divided into multiple heating blocks 120, with the multiple heating blocks 120 of each heating strip 110 arranged along the front-to-back direction. The first direction intersects with the second direction, causing the multiple heating strips 110, multiple first wires 210, and multiple second wires 220 to form a grid-like circuit layout. Preferably, the first direction and the second direction are perpendicular to each other. The left end of the multiple first wires 210 is used to connect to the positive terminal of the power supply, and the right end of the multiple second wires 220 is used to connect to the negative terminal of the power supply. Both the first wires 210 and the second wires 220 are made of conductive silver, and the conductive silver covers the upper surface of the substrate 100.

[0040] By decomposing the originally single, continuous heating circuit into a multi-parallel structure composed of multiple heating elements 110, a first wire 210, and a second wire 220, the single-point failure problem of traditional designs is solved. Specifically, the first wire 210 serves as the main positive trunk line, the second wire 220 serves as the main negative trunk line, and each heating block 120, separated from it, constitutes an independent parallel branch. This design has high redundancy. Conductive silver is used as the material for the first wire 210 and the second wire 220, chosen based on silver's excellent conductivity. This ensures that the voltage drop and power loss of the wires themselves can be minimized during current transmission and distribution, allowing most of the electrical energy to be concentrated on the heating elements 110, which have higher resistivity, for efficient conversion, improving energy utilization efficiency, and avoiding unintended heating of the wires. This layout also greatly simplifies the calculation and control of thermal power; the total power is approximately the product of the power of a single heating block 120 and the total number of heating blocks 120, facilitating modular design according to requirements.

[0041] Understandably, after power is applied, the current moves along the first wire 210. After passing through the heating strip 110, the current is split and flows through multiple heating blocks 120. The heating blocks 120 of the heating strip 110 heat up after being energized, thus heating the substrate 100. The current then merges into the second wire 220. During this process, the first wire 210, the second wire 220, and the heating strip 110 form a gridded parallel circuit layout. When one heating block 120 melts, the current can still flow through other parallel paths. The entire multi-parallel circuit thick-film heating element will not immediately fail, greatly improving reliability and service life. Specifically, when a heating block 120 melts for any reason, it only means that the parallel branch becomes an open circuit, and the current in that branch drops to zero. However, since all heating blocks 120 are in parallel, the voltage applied across other normal heating blocks 120 remains unchanged. Therefore, the current and heating power of other branches are basically unaffected. The total power of the entire heating element will decrease slightly, but its core heating function is maintained, preventing complete failure. This allows the heating element to continue operating even with localized defects, significantly extending its effective service life. Alternatively, in addition to conductive silver, gold or copper-based conductive pastes with equally excellent conductivity can be used to fabricate the first wire 210 and the second wire 220. Furthermore, the current is evenly distributed across the entire heating area via multiple paths, improving heat distribution and preventing localized overheating. This uniform distribution stems from the physical characteristics of parallel circuits. Ideally, if all heating blocks 120 have the same resistance, the current flowing through each heating block 120 will also be identical, resulting in the same heating power (P = I²R) for each heating block 120. This gridded layout divides the entire heating surface into multiple independent, power-controllable heating units, ensuring that heat is generated discretely and uniformly from the outset, rather than from a single, winding line source. This avoids the hot spot problem caused by circuit bending and density changes in traditional designs from the source, making the temperature distribution of the entire substrate 100 more uniform and improving the heating quality. It is especially suitable for application scenarios with high requirements for temperature uniformity.

[0042] Preferably, the width of the heating strip 110 is greater than the width of the first wire 210 and the second wire 220. A larger width, i.e., a larger cross-sectional area, allows for a lower resistance value under given material resistivity and length, thus achieving higher heating power at rated voltage. The first wire 210 and the second wire 220, as conductive buses, function to transmit current with low loss, not to generate heat. Therefore, using a high-conductivity material (such as conductive silver) combined with a narrow width ensures that its own resistance is much lower than that of the heating block 120, while guaranteeing sufficient current carrying capacity. This "wide heating strip 110, narrow wire" structure ensures that the vast majority of electrical energy is used for the target heating area, rather than being wasted on the transmission lines. The heating strip 110, the first wire 210, and the second wire 220 can be formed in one step using processes such as screen printing, simplifying the production process.

[0043] Preferably, the thickness of the heating strip 110 is the same as or substantially the same as the thickness of the first wire 210 and the second wire 220. Since the heating strip 110, the first wire 210, and the second wire 220 are typically formed on the same plane in one step or in stages using thick-film processes such as screen printing, uniform thickness is achieved using the same printing process parameters. This consistency in thickness simplifies the manufacturing process, reduces the complexity of process control, and thus effectively controls production costs and improves yield. Moreover, with consistent thickness, the cross-sectional area of ​​each circuit element is proportional to its width, making the resistance value of the element mainly determined by its material resistivity and the width of the planar design. Therefore, designers can more intuitively and precisely differentiate and control the heating power and conductivity by adjusting the width of the heating strip 110, the first wire 210, and the second wire 220, and by selecting pastes with different resistivities. This ensures that most of the electrical energy is converted into heat energy on the wide heating strip 110, with minimal loss on the narrow conductive silver first wire 210 and the second wire 220, thereby achieving a highly efficient and flexible heating function.

[0044] According to some embodiments of this utility model, refer to Figure 1Among the multiple heating blocks 120 of the heating strip 110, at least two heating blocks 120 have unequal widths. The wider the heating block 120, the lower its resistance. In a parallel circuit, the voltage of each branch is the same; the area with lower resistance has greater heating power. The widths of different heating blocks 120 can be adjusted according to requirements. Utilizing the principle that the voltage (V) of each branch in a parallel circuit is constant, and the power formula P = V² / R and the resistance formula R = ρL / A (where ρ is resistivity, L is length, and A is cross-sectional area), it can be seen that the heating power P is inversely proportional to the resistance R, and the resistance R is inversely proportional to the cross-sectional area A (directly proportional to the width W). Therefore, the heating power P is directly proportional to the width W of the heating block 120. By designing heating blocks 120 of different widths on the same heating strip 110, precise control of the heating power in different areas can be achieved without changing the supply voltage or adding additional control circuitry. For example, in core areas requiring rapid heating or maintenance of higher temperatures, wider heating blocks 120 can be designed to achieve higher power density. This built-in power distribution design provides an extremely flexible and cost-effective solution for meeting complex, non-uniform heating needs.

[0045] Preferably, in a heating strip 110, the width of the foremost and rearmost heating blocks 120 in the left-right direction is larger than the width of the other heating blocks 120 in the left-right direction. It is understood that in the edge areas where heat dissipation is easier, the width of the heating blocks 120 in the corresponding heating strip 110 is wider to compensate for heat loss. In the central area, the heating blocks 120 are narrower, ultimately achieving a uniform temperature across the entire heating plate. Due to heat conduction and convection, the heat dissipation rate in the edge areas is usually much higher than in the central area, which naturally leads to a lower edge temperature than the center temperature. This embodiment configures the highest-power (widest) heating block 120 in the edge areas where heat dissipation is fastest, and a lower-power (narrower) heating block 120 in the central area where heat dissipation is slower, thereby actively and specifically compensating for heat in the edge areas. The synergistic effect of this design lies in using the inherent characteristics of the circuit layout to solve a common thermodynamic problem, ultimately ensuring that the surface temperature of the entire heating plate tends to be highly uniform when thermal equilibrium is reached. This method of achieving a uniform temperature field has significant advantages over using complex external temperature sensors and multi-channel controllers, including simple structure, low cost, rapid response, and high reliability.

[0046] According to some embodiments of this utility model, refer to Figure 1 and Figure 2The multi-parallel circuit thick-film electric heating element also includes a first insulating layer 310, which is located between the substrate 100 and the heating strip 110. First wires 210 and second wires 220 are both located on the side of the first insulating layer 310 away from the substrate 100, i.e., on the upper side of the first insulating layer 310. A first electrode 410 and a second electrode 420 are located on the side of the first insulating layer 310 away from the substrate 100, i.e., on the upper side of the first insulating layer 310. The left ends of the multiple first wires 210 are connected to the first electrode 410 via conductive silver, and the right ends of the multiple second wires 220 are connected to the second electrode 420 via conductive silver. Both the first wires 210 and the second wires 220 are also made of conductive silver. The first insulating layer 310 serves a dual function of electrical isolation and heat conduction. When the substrate 100 is made of a conductive material such as metal, the first insulating layer 310 effectively prevents short circuits between the heating circuit and the substrate 100, ensuring the basic electrical safety and normal operation of the electric heating element. At the same time, the first insulating layer 310 must have good thermal conductivity so that the heat generated by the heating strip 110 can be transferred to the substrate 100 efficiently and with low loss, and then transferred from the substrate 100 to the object being heated.

[0047] The heating strip 110, the first wire 210, the second wire 220, the first electrode 410, and the second electrode 420 are all located on the first insulating layer 310.

[0048] According to some embodiments of this utility model, refer to Figure 1 and Figure 2 The multi-parallel circuit thick-film heating element also includes a second insulating layer 320. The second insulating layer 320 is located above the heating strip 110, which is located above the first insulating layer 310. The second insulating layer 320 covers the side of the heating strip 110 away from the first insulating layer 310. The second insulating layer 320 simultaneously covers the first wire 210 and the second wire 220 and exposes the first electrode 410 and the second electrode 420. The first electrode 410 is used to connect to the positive terminal (or phase wire) of the power supply, and the second electrode 420 is used to connect to the negative terminal (or neutral wire) of the power supply. The second insulating layer 320 mainly serves a sealing and protective function. It completely isolates the entire heating circuit from the external environment, effectively preventing circuit corrosion or short circuits caused by moisture, dust, chemicals, etc., thereby enhancing the durability and environmental adaptability of the heating element. Simultaneously, it also provides a layer of safety insulation for the user, preventing the risk of accidental electric shock. Exposing the first electrode 410 and the second electrode 420 allows for the preservation of necessary electrical connection interfaces.

[0049] The first insulating layer 310 and the second insulating layer 320 are alumina ceramic layers. Preferably, a fluoropolymer coating can be sprayed onto the surface of the alumina ceramic layer. The minimum operating temperature of the alumina ceramic layer is 500℃. The alumina and fluoropolymer composite layer has higher insulation performance and can operate continuously at 240-250℃. This insulating layer has good insulation, thermal conductivity, and corrosion resistance. Alumina ceramic, as an insulating layer material, has an operating temperature exceeding 500℃, ensuring structural stability and no degradation of insulation performance under high-temperature operating conditions. Its high dielectric strength provides reliable electrical insulation. Its relatively high thermal conductivity meets the requirements of efficient heat transfer. In addition, alumina also has high hardness and wear resistance. The addition of the fluoropolymer coating enhances the functionality based on the excellent properties of alumina. Fluoropolymers have excellent chemical stability and hydrophobicity, further improving the surface's corrosion resistance and waterproof / moisture-proof capabilities, while providing non-adhesive properties. The synergistic effect of the two provides more comprehensive protective performance and further extends service life.

[0050] According to some embodiments of this utility model, the substrate 100 is a metal substrate or a non-metal substrate. When the substrate 100 is a metal substrate, it is made of aluminum, carbon steel, cast iron, stainless steel, copper, or a copper alloy. It possesses good comprehensive mechanical properties, and the surface of the substrate 100 can be planar, curved, etc., and its shape can have a structure compatible with the final utility, such as square, circular, tubular, or other three-dimensional shapes. Non-metallic substrates include glass, silicon carbide, silicon nitride, alumina, zirconium oxide, boron nitride, etc.

[0051] According to some embodiments of this utility model, the substrate 100 is in the form of a sheet, a sheet with water channels, or a tube. This allows the multi-parallel circuit thick-film electric heating element to be applicable to a variety of electric heating devices, such as instant dual-mode water heaters, instant electric water heaters, hair straighteners, curling irons, automotive exhaust oxidation sensors, industrial equipment heaters, ultrasonic electric heating elements, mold heating and insulation devices, medical device heaters, air heaters, and small heating appliances, etc.

[0052] Preferably, the heating element 110 is a nickel-chromium heating coating made of nickel-chromium slurry, replacing traditional palladium-based or ruthenium-based slurries, reducing the amount of rare metals used. This heating element 110 is resistant to dry burning and sudden load impacts, and has advantages such as uniform heating surface, low thermal inertia, strong thermal shock resistance, and large heating area per unit volume, thus improving the service life of the heating element and reducing manufacturing costs. The nickel-chromium heating coating includes nickel powder, chromium powder, glass powder, and an organic carrier. The nickel-chromium heating layer is made of nickel-chromium slurry, which is prepared from the following raw materials in the following mass percentages: 50%–70% nickel powder, 10%–25% chromium powder, 2%–6% glass powder, and 15%–25% organic carrier; wherein the particle size distribution D50 of the nickel powder is 3μm–5μm, and the particle size distribution D50 of the chromium powder is 1μm–3μm. The organic carrier includes solvents, resins, and additives. The organic carrier is prepared from raw materials comprising the following mass percentages: 80%–92% solvent, 5%–10% resin, and 3%–6% additives; wherein the additives include at least one selected from oleic acid, Span-85, lecithin, and polyethylene glycol. Adding an appropriate amount of organic carrier to nickel-chromium paste can adjust the viscosity of the electrothermal paste, giving it a suitable viscosity and improving its ease of use.

[0053] In this specification, the reference to the term "some embodiments" means that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0054] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A multiple parallel circuit thick film electrocaloric element, characterized by, include: Matrix (100); A heating strip (110) is disposed on the substrate (100), the heating strip (110) extends along a first direction, and a plurality of heating strips (110) are arranged parallel to each other and spaced apart; A first wire (210) extends along a second direction, a plurality of first wires (210) are spaced apart along the first direction, and each first wire (210) is electrically connected to a plurality of heating strips (110). The first direction intersects the second direction, and one end of the plurality of first wires (210) is used to connect to the positive terminal of the power supply. The second wire (220) extends along the second direction, and a plurality of the second wires (220) are arranged at intervals along the first direction, and each of the second wires (220) is electrically connected to a plurality of the heating strips (110), and one end of the plurality of the second wires (220) is used to connect to the negative terminal of the power supply; Multiple first wires (210) and multiple second wires (220) are arranged alternately along a first direction, such that each heating strip (110) is divided into multiple heating blocks (120).

2. The multiple parallel circuit thick film electrocaloric element of claim 1, wherein, The width of the heating strip (110) is greater than the width of the first wire (210) and the second wire (220).

3. The multiple parallel circuit thick film electrocaloric element of claim 1, wherein, The first direction and the second direction are perpendicular to each other to form a grid-like circuit layout.

4. The multiple parallel circuit thick film electrocaloric element of claim 1, wherein, Among the plurality of heating blocks (120) of the heating strip (110), at least two heating blocks (120) have unequal widths.

5. The multiple parallel circuit thick film electrocaloric element of claim 1, wherein, The multi-parallel circuit thick film heating element further includes a first insulating layer (310), which is located between the substrate (100) and the heating strip (110). The first wire (210) and the second wire (220) are both disposed on the side of the first insulating layer (310) away from the substrate (100). The side of the first insulating layer (310) away from the substrate (100) is provided with a first electrode (410) and a second electrode (420). One end of the plurality of first wires (210) is connected to the first electrode (410), and one end of the plurality of second wires (220) is connected to the second electrode (420).

6. The multiple parallel circuit thick film electrocaloric element of claim 5, wherein, The multi-parallel circuit thick film heating element further includes a second insulating layer (320), which covers the side of the heating strip (110) away from the first insulating layer (310). The second insulating layer (320) covers both the first wire (210) and the second wire (220) and exposes the first electrode (410) and the second electrode (420). The first electrode (410) is used to connect to the positive terminal of the power supply, and the second electrode (420) is used to connect to the negative terminal of the power supply.

7. The multiple parallel circuit thick film electrocaloric element of claim 1, wherein, The substrate (100) is a metal substrate or a non-metal substrate.

8. The multiple parallel circuit thick film electrocaloric element of claim 1, wherein, The substrate (100) is aluminum, carbon steel, cast iron, stainless steel, copper, or a copper alloy.

9. The multiple parallel circuit thick film electrocaloric element of claim 1, wherein, The substrate (100) is in the form of sheets or tubes.

10. An electrothermal apparatus, characterized by It includes a multi-parallel circuit thick film heating element as described in any one of claims 1 to 9.

Images