Special-shaped transparent heating element and preparation method thereof
By designing parallel heating channels and grid lines in the transparent heating element, the problems of uneven resistance and broken wires are solved, achieving uniform heating and high transparency within the irregular surface, thus improving the safety and reliability of the product.
Patent Information
- Application Number
- CN202511573515.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-31
- Publication Date
- 2026-01-20
AI Technical Summary
Existing transparent heating elements are prone to cracking on irregular curved surfaces or flexible substrates, resulting in a sharp increase in resistance and uneven current density, leading to localized overheating or cold spots, which affects the performance and safety of the product. Furthermore, the metal mesh is at risk of breakage during the manufacturing or use process, which reduces product yield and long-term reliability.
The design incorporates multiple parallel heating channels, each with equal length and width. A metal mesh is constructed using parallel grid lines, and an irregular grid pattern is prepared through embossing or additive manufacturing processes. High-conductivity feeder edges are added to the edges to ensure uniform current distribution and transmission, preventing functional failure caused by single-point wire breakage.
It achieves uniform heating of the heating element within irregularly shaped surfaces, improving safety and product stability, avoiding moiré stripe interference, and is suitable for applications with high visual effect requirements.
Smart Images
Figure CN121368043A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of transparent heating elements, in particular to a special-shaped transparent heating element and a preparation method thereof. BACKGROUND
[0002] As a functional optical element, transparent heating elements are widely used in defrosting and demisting of windshields and observation windows in the fields of automobiles and aerospace, and in display area heat preservation of consumer electronic products. The core requirement is to achieve rapid and uniform heating performance while ensuring high light transmittance, and to have good reliability and environmental adaptability.
[0003] Currently, transparent heating technology is mainly based on two types of material systems: one is the use of transparent conductive films of metal oxides such as indium tin oxide (ITO); the other is the use of metal micro-meshes made of silver, copper, etc. Although ITO films have the advantages of high light transmittance and uniform surface resistance, their inherent brittleness makes them prone to cracking when applied to special-shaped curved surfaces or flexible substrates, leading to a dramatic increase in resistance and functional failure. At the same time, indium, as a rare metal, is high in cost and unstable in supply chain.
[0004] Although metal mesh technology, especially mesh prepared by printing, etching or embossing process, has better flexibility and conductivity, it still faces challenges in practical application: to achieve uniform heating in complex shapes, the wiring design of the heating circuit is crucial. If the resistance of each parallel heating channel is different, it will lead to uneven current density, and then cause local overheating or cold areas, affecting the use effect and safety. Extremely fine metal mesh lines have the risk of breaking due to microscopic defects, corrosion or stress concentration during preparation or use. A single broken line can cause the entire heating channel to fail, significantly reducing the yield and long-term reliability of the product. SUMMARY
[0005] The purpose of the present application is to provide a special-shaped transparent heating element and a preparation method thereof to solve the problems raised in the background art.
[0006] To achieve the above purpose, the present application provides the following technical solution: a special-shaped transparent heating element, comprising a substrate and a heating film arranged on the substrate, the heating film comprising a plurality of parallel heating channels, the length of each heating channel being equal and the width being equal, so that the heating film is uniform in area heating;
[0007] The heating channel is formed by breaking the line, and the width of the broken line is 5-30 μm.
[0008] Preferably, each of the heating channels comprises at least two parallel mesh lines.
[0009] Preferably, the grid lines form a metal grid, the line width of the grid lines is 3-30 microns, and the metal grid is prepared by a printing, additive or subtractive process and forms an irregular grid pattern.
[0010] Preferably, the heating film is a transparent conductive film prepared by a coating or plating process, and the transparent conductive film includes an ITO film layer.
[0011] Preferably, the substrate is a high-temperature-resistant transparent material selected from one of PMMA, PC, glass, CPI, and PEN.
[0012] Preferably, the profiled transparent heating element further includes a feeder edge line, the feeder edge line is arranged at the edge of the heating film and is made of a high-conductivity material selected from a silk-screen silver paste, a conductive copper foil or an alloy.
[0013] Preferably, the light transmittance of the heating film is adjusted by the line width of the grid lines and the total length of the grid line segments.
[0014] Preferably, the uniform heating area of the heating film is formed by a plurality of parallel heating channels and at least two parallel grid lines, and a working voltage is applied through the feeder edge line.
[0015] A preparation method of a profiled transparent heating element, the preparation method is applied to the profiled transparent heating element, and the preparation method includes the following steps:
[0016] S1: providing a substrate, the substrate is a high-temperature-resistant transparent material;
[0017] S2: forming a heating film on the substrate, the heating film includes a plurality of parallel heating channels, the length of each heating channel is equal, and the width of each heating channel is equal;
[0018] S3: arranging a feeder edge line, the feeder edge line is made of a high-conductivity material and is applied to the edge of the heating film by silk-screen printing, pasting or deposition.
[0019] S4: forming a metal grid of the heating film by a printing, additive or subtractive process.
[0020] Compared with the prior art, the profiled transparent heating element has the following beneficial effects:
[0021] 1. The profiled transparent heating element ensures that the resistance values of the channels are consistent by designing a plurality of parallel heating channels, each channel has an equal length and an equal width, the power density is uniform under the same voltage, thereby fundamentally solving the problem of uneven heating caused by resistance difference and improving the heating effect and safety.
[0022] 2. The application prevents the failure of the entire heating channel and significantly enhances the anti-fracture capability and long-term use stability of the product by containing at least two parallel grid lines in each heating channel, so that when a single grid line is broken due to microscopic defects, corrosion or stress, the current can still be transmitted through other grid lines.
[0023] 3. The application avoids optical interference with structures such as display pixels, eliminates Moire fringes, and makes the heating element almost invisible in a transparent state by using an irregular grid pattern and extremely thin grid lines, making it suitable for application scenarios with high visual effect requirements. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 The figure is a schematic diagram of the layered structure of the special-shaped transparent heating element of the application.
[0025] Figure 2 The figure is a schematic diagram of the structure of the heating film of the application.
[0026] In the figure: 1 - substrate; 2 - heating film; 21 - metal grid; 3 - heating channel; 31 - grid line; 4 - breaking line; 5 - feeder edge line. DETAILED DESCRIPTION
[0027] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.
[0028] The application provides a technical solution: a special-shaped transparent heating element provided by the embodiments of the application, as shown in the accompanying Figure 1 The figure is a schematic diagram of the layered structure of the special-shaped transparent heating element of the application.
[0029] The figure is a schematic diagram of the layered structure of the special-shaped transparent heating element of the application. Figure 2 As shown in the accompanying
[0030] Wherein, p is the material conductivity, l is the single-channel length, h is the single-channel width, and d is the material thickness. When the length l and the width h of each channel are equal, the resistance values R are approximately equal.
[0031] Since each heating channel 3 is connected in parallel, the surface resistance of the heating film is n channels in parallel,
[0032]
[0033] Since R1 = R i , then
[0034] The power density formula of each channel is:
[0035]
[0036] Each channel is in parallel, the power supply voltage is consistent, and the length of each parallel channel is equal, and the width is approximately equal, so the power density of each channel is consistent, and therefore the heating film surface area is evenly heated, fundamentally solving the technical problem of local overheating or cold area caused by resistance difference of parallel channels.
[0037] As shown in the accompanying Figure 2 , the heating channel 3 is formed by breaking the line 4, the width of the broken line 4 is 5-30 μm, and the broken line 4 is used to divide the continuous conductive layer into a predetermined current path, i.e. the heating channel 3, and the width is set to minimize the interference with the visual effect while ensuring the reliability of electrical isolation.
[0038] In the embodiment of the present application, at least two parallel grid lines 31 are included in each heating channel 3, and when a certain grid line 31 breaks at a certain point due to microscopic defects, corrosion or stress, the current can still be transmitted through other parallel grid lines in the channel, thereby preventing the entire heating channel from losing function due to a single-point broken line, and significantly improving the yield and long-term reliability of the product.
[0039] As shown in the accompanying Figure 2 , the grid line 31 constitutes a metal grid 21, and the line width of the grid line 31 is 3-30 μm, which is thin enough to be difficult to distinguish by the human eye while ensuring sufficient conductive cross-sectional area to carry current, thereby maintaining high visual light transmittance.
[0040] The metal grid 21 is prepared by embossing, additive or subtractive process, and forms an irregular grid pattern, which is used to avoid optical interference or diffraction with regular patterns and display pixels and other structures, thereby eliminating undesirable visual effects such as Moire fringes.
[0041] In a preferred preparation embodiment, the metal grid 21 is prepared by nano-imprinting process, which first coats a layer of metal nanoparticle ink on the surface of the substrate 1, then uses a mold with a predetermined irregular pattern for embossing, and finally forms a solidified metal grid 21 by curing and sintering.
[0042] As another embodiment, the heating film 2 can be a transparent conductive film, such as an ITO film layer, prepared by coating or plating process, which is suitable for application scenarios with very high requirements for surface flatness and not very complex shape.
[0043] The substrate 1 is a high-temperature-resistant transparent material selected from one of PMMA, PC, glass, CPI and PEN, which provides mechanical support and protection for the heating film 2 and resists the temperature generated during the operation of the heating element, and in a preferred embodiment, the substrate 1 is made of polycarbonate PC, which has excellent light transmission, mechanical strength and heat resistance, can resist the temperature generated during the operation of the heating film, and is suitable for the fields of automobiles and electronics, and in other embodiments, the substrate 1 can also be selected from PMMA, glass, CPI or PEN to meet the specific requirements of flexibility, scratch resistance or cost in different application scenarios.
[0044] The profiled transparent heating element provided by the embodiment of the present application further comprises a feeder edge line 5 arranged at the edge of the heating film 2 and made of a high-conductivity material selected from screen-printed silver paste, conductive copper foil or alloy, and in a preferred embodiment, the feeder edge line 5 is made of screen-printed silver paste, which serves as a low-resistance current bus bar to uniformly distribute the current from the external power supply to each heating channel 3 and collect the current, thereby ensuring the consistency of the voltage at the edge of the entire heating area.
[0045] The light transmittance of the heating film 2 is adjusted by the line width of the grid lines 31 and the total length of the grid line segments, and the light transmittance T of the heating film 2 and the line width w of the grid lines 31 and the total length L of the grid line segments in a unit area satisfy the functional relationship T=f(w, L).
[0046] Specifically, the light transmittance T value decreases with the increase of the product of the line width w and the total length L, and by accurately designing and optimizing the two key structural parameters of the line width w of the grid lines 31 and the total length L of the grid line segments of the pattern, the visual light transmittance of the heating film 2 can be flexibly adjusted and optimized to the target value while ensuring the required conductive performance, thereby achieving a good balance between optical and electrical performance.
[0047] The uniform heating area of the heating film 2 is composed of a plurality of parallel heating channels 3 and at least two parallel grid lines 31, and a working voltage is applied through the feeder edge line 5, and the explicit connection and synergistic effect of this series of structures jointly ensure that the profiled transparent heating element realizes uniform, reliable and high-transparency heating function in a complex shape.
[0048] The embodiment of the present application further provides a method for preparing the profiled transparent heating element, and the preparation method comprises the following steps:
[0049] S1: providing a substrate 1 made of a high-temperature-resistant transparent material;
[0050] S2: forming a heating film 2 on the substrate 1, the heating film 2 comprising a plurality of parallel heating channels 3, each heating channel 3 having equal length and equal width;
[0051] S3: A feed line border 5 is provided, which is made of a high conductivity material and applied to the edge of the heating film 2 by means of silk screen printing.
[0052] S4: The heating film 2 is formed by means of a screen printing process to produce a metal grid 21.
[0053] While embodiments of the application have been shown and described, it is to be understood that the application is not limited to the details of the embodiments described, since numerous changes, modifications, substitutions and alterations can be made thereto without departing from the spirit and scope of the application as defined by the appended claims and their equivalents.
Claims
1. A profiled transparent heating element comprising a substrate (1) and a heating film (2) arranged on the substrate (1), characterized in that: The heating film (2) comprises a plurality of parallel heating channels (3), each heating channel (3) has equal length and equal width, so that the heating film (2) has uniform in-plane area heating; The heating channel (3) is formed by breaking the line (4), and the width of the broken line (4) is 5-30 μm.
2. A profiled transparent heating element according to claim 1, characterised in that: Each of the heating channels (3) comprises at least two parallel grid lines (31).
3. A profiled transparent heating element according to claim 2, wherein: The grid lines (31) form a metal grid (21), the line width of the grid lines (31) is 3-30 μm, and the metal grid (21) is prepared by a printing, additive or subtractive process and forms an irregular grid pattern.
4. A profiled transparent heating element according to claim 1, wherein: The heating film (2) is a transparent conductive film prepared by a coating or plating process, and the transparent conductive film comprises an ITO film layer.
5. A profiled transparent heating element according to claim 1, wherein: The substrate (1) is a high-temperature-resistant transparent material selected from one of PMMA, PC, glass, CPI and PEN.
6. A profiled transparent heating element according to claim 1, wherein: The special-shaped transparent heating element further comprises a feeder edge line (5), the feeder edge line (5) is arranged at the edge of the heating film (2) and is made of a high-conductivity material selected from screen-printed silver paste, conductive copper foil or alloy.
7. A profiled transparent heating element according to claim 2, wherein: The light transmittance of the heating film (2) is adjusted by the line width of the grid lines (31) and the total length of the grid line segments.
8. A profiled transparent heating element according to claim 6, wherein: The uniform heating area of the heating film (2) is formed by a plurality of parallel heating channels and at least two parallel grid lines (31), and a working voltage is applied through the feeder edge line (5).
9. A method of making a shaped transparent heating element, characterized by: The preparation method is applied to the special-shaped transparent heating element according to any one of claims 1-8, and the preparation method comprises the following steps: S1: providing a substrate (1), the substrate (1) is a high-temperature-resistant transparent material; S2: forming a heating film (2) on the substrate (1), the heating film (2) comprises a plurality of parallel heating channels (3), each heating channel (3) has equal length and equal width; S3: providing a feeder edge line (5), the feeder edge line (5) is made of a high-conductivity material and is applied to the edge of the heating film (2) by screen printing, pasting or deposition; S4: forming a metal grid (21) of the heating film (2) by a printing, additive or subtractive process.