Patent ID: 12225637

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention aims to provide a curved surface heating device and a manufacturing method thereof, which can be used for curved shells or curved shapes, through a flexible 3D pattern element forming method to process functional circuits or patterns, such as conductive circuits or insulating circuits, onto curved shells or curved shapes to solve the problem of damaging functional circuits or patterns that may occur during processing of conventional screen printing.

In order to better understand the technical features and practical effects of the present invention and to implement the present invention in accordance with the contents of the specification, further detailed descriptions will be provided below with reference to a first preferred embodiment as shown inFIG.1.

“Curved Surface Heating Device”

FIG.1shows the first preferred embodiment of the curved surface heating device provided by the present invention. The curved surface heating device includes sequentially stacked layers of a protective layer10, a bonding layer20, a conductive layer30, a temperature control insulation layer40, and an insulation layer50. The curved surface heating device can be heated by electrical conduction to maintain a fixed temperature range, thereby producing temperature control and insulation effects. At the same time, since the curved surface heating device is manufactured using the flexible 3D pattern element forming method, the curved surface heating device can be applied to curved shells or components having curved shapes. In addition, the curved surface heating device has a wide range of applications and can be used to produce parts for transportation vehicles, lamp covers, traffic signals, lenses, goggles, signal sensors, display panels, mirrors, and other daily necessities.

Referring toFIGS.1and2. The protective layer10is a transparent material with dielectric properties and is curved in shape. During manufacturing, the protective layer10can be formed into a curved shape by processing a plastic base material with a flat panel shape. The processing conditions may involve applying heat and an external force to soften the protective layer10and deform the protective layer10along a force point corresponding to the external force, thereby transforming the protective layer10from original flat panel shape to curved panel shape with convex and concave directions. Importantly, the protective layer10maintains its curved panel shape even after the external force is removed.

Wherein, the protective layer10can be made of plastic or glass; preferably, the protective layer10is made of materials such as polycarbonate (PC), polypropylene (PP), or polyethylene (PE).

Wherein, the bonding layer20, the conductive layer30, the temperature control insulation layer40, and the insulation layer50are formed on one side of the protective layer10. In this embodiment, the bonding layer20, the conductive layer30, the temperature control insulation layer40, and the insulation layer50are formed on a concave surface101of the protective layer10. Subsequently, the concave surface101will be used as an embodiment for description.

The bonding layer20is formed by curing a transparent adhesive and is used to tightly bond to the protective layer10, the conductive layer30, and/or the temperature control insulation layer40. The bonding layer20also has dielectric and flexibility properties, and the material is preferably an optical clear adhesive. The form of the bonding layer20is not limited and can be selected based on the material of the protective layer10, such as whether the bonding layer20is a thin film or a liquid adhesive. The bonding layer20can be processed onto the protective layer10by methods such as coating, pad printing, reprinting, transfer printing, in-mold printing, 3D printing, inkjet printing, gravure printing, etc.

In this embodiment, the bonding layer20is in a fluid state when adhered to the conductive layer30, and the total area of the bonding layer20is slightly larger than that of the conductive layer30and/or the temperature control insulation layer40.

The conductive layer30is a layer having electrothermal properties and can be a thin film or can be formed by curing the liquid adhesive. The conductive layer30can generate heat when input current to make the curved surface heating device has a defrosting, defogging, and/or demisting effect. Preferably, a resistance value of the conductive layer30is within 300Ω and a current withstand value is less than 2 A. The conductive layer30may be a conductive adhesive, which is the liquid adhesive having electrothermal properties, and may be opaque or transparent.

Preferably, the conductive adhesive can be a gel formed by mixing high-conductivity materials such as conductive metals or carbon-based materials with resin solvents. Wherein, a volume percentage of the conductive metal in the high-conductivity material is between 30% and 60%, and a volume percentage of the carbon-based material in the high-conductivity material is between 30% and 60%. The conductive metal and/or the carbon-based material may be granular, flaky, or in the form of short fibers. It should be noted that when the conductive metal is flaky, it not only contributes to the conductivity of the conductive adhesive, but also increases the overall structural strength after the conductive adhesive is cured.

Furthermore, the conductive metal is preferably silver, copper, gold, aluminum, and the carbon-based material may preferably include carbon nanotubes, carbon fibers, or modified compounds of the above materials.

It should be noted that due to the properties of the material, the conductive layer30can be presented in a transparent or opaque form. For example, when the curved surface heating device is applied in the form of a vehicle lamp shell A as shown inFIG.9, the conductive layer30can choose the liquid adhesive or the thin film with transparency so that when a user activates the vehicle lamp component B, light from the inside of the vehicle lamp component B can pass through the vehicle lamp shell A, reducing the attenuation of the light when passing through the vehicle lamp shell A, thereby increasing the safety of the user when using the vehicle lamp component B. When the conductive layer30is made of the liquid adhesive or the film with transparency, the transmittance of the conductive layer30is preferably over 80%.

Wherein, the conductive layer30is distributed on the bonding layer20using the flexible 3D pattern element forming method provided by the present invention. Furthermore, through the flexible 3D pattern element forming method, the conductive layer30can be further stacked with the conductive adhesive continuously to increase the thickness of the conductive layer30. Preferably, a thickness of the conductive layer30is within 50 micrometers (μm).

Furthermore, the curved surface heating device is electrically connected to a power supply device via the conductive layer30. Due to the material properties of the conductive layer30mentioned above, the conductive layer30can generate electrothermal properties after receiving electricity. The power supply device can be presented in the form of a battery or connected to a wall outlet. Preferably, the power supply device can provide power in the form of alternating current or direct current.

Wherein, the use of the bonding layer20can be determined based on the material selection of the conductive layer30. For example, if the conductive layer30is made of the conductive metal, which results in a lower adhesion of the conductive layer30, in that case, the bonding layer20can be coated on one side of the protective layer10before the conductive layer is placed to strengthen the bond between the conductive layer30and the protective layer10.

Furthermore, the conductive layer30may also be mixed with the adhesive of the bonding layer20prior to being placed on one side of the protective layer10.

It should be noted that when the bonding layer20is the liquid adhesive, during the setting of the conductive layer30using the flexible 3D pattern element forming method, due to the flowability of the bonding layer20, at least a portion of the bonding layer20comes into contact with a lateral surface31of the conductive layer30in the thickness direction, which helps to bond the conductive layer30to the protective layer10. Furthermore, when the bonding layer20abuts the conductive layer30, pressure causes the bonding layer20to fluidly envelope the entire thickness of the lateral surface31of the conductive layer30, causing the bonding layer20and the conductive layer30to form a plane together, thereby overcoming the problem of the difficulty in placing the conductive layer30within the curved surface heating device due to the thickness of the conductive layer30.

Furthermore, it is optional to place the temperature control insulation layer40on one side of the conductive layer30, i.e., the temperature control insulation layer40can be added before or after the conductive layer30is placed.

The temperature control insulation layer40is cured of a carbon-containing adhesive and has a thermal insulation effect that can maintain the overall temperature of the lamp component B (including the temperature generated by the conductive layer30) within a specific range to prevent the temperature of the lamp component B from continuously rising and damaging the lamp component B, thereby achieving the temperature control and insulation effects. Wherein the temperature range is from 30° C. to 100° C. The carbon-containing adhesive may contain carbon-based materials, and the carbon-based materials include graphite or carbon nanotubes.

Preferably, with reference toFIGS.6and7, the temperature control insulation layer40is a carbon-containing conductive adhesive having electrothermal properties that can assist in transmitting current to the conductive layer30. The carbon-containing conductive adhesive is a metal-carbon mixture formed by mixing the conductive metal with the carbon-based materials. The conductive metal includes the silver, copper, gold or aluminum, and other high-conductivity metal materials. The carbon-based materials include graphite or carbon nanotubes. Furthermore, in the carbon-containing conductive adhesive, a volume percentage of the conductive metal is between 10% and 25% and a volume percentage of the carbon-based material is between 30% and 60%.

In this embodiment, the temperature control insulation layer40is disposed on the opposite side of the conductive layer30from the protective layer10. At least one conductive wire30A is electrically connected to the temperature control insulation layer40. After the temperature control insulation layer40is electrified, when the conductive metal which is adjacent to the position of the conductive wire30A receives electric current, due to the lower proportion of the conductive metal, the current will be initially passed only to the conductive layer30, while the other conductive metals which do not receive the current will perform temperature maintenance effects with the carbon-based materials to prevent overheating. It should be noted that when the temperature control insulation layer40is placed between the conductive layer30and at least one of the conductive wires30A, in addition to serving as a current transmission application, it can also effectively prevent oxidation of the conductive layer30.

Furthermore, the temperature control insulation layer40may also include the various different conductive metals, such as the carbon-containing conductive adhesive made by mixing silver, nickel, and the carbon-based materials. It should be noted that since the carbon-containing conductive adhesive retains the properties of the carbon-based materials, even when the carbon-containing conductive adhesive is added with the high-conductivity metal materials, it can still maintain the temperature within the specific range, thereby preventing the occurrence of overheating in the vehicle lamp component B.

In this embodiment, the conductive layer30and the temperature control insulation layer40are sequentially bonded to the bonding layer20using the flexible 3D pattern element forming method. The flexible 3D pattern element forming method will be described in the following paragraphs.

The insulation layer50is a material with dielectric and high-temperature resistance properties. The insulation layer50is used as an enveloping structure and is enveloped on the bonding layer20, the conductive layer30, and/or the temperature control insulation layer40in the direction of the temperature control insulation layer40to form a multi-layer structure, to achieve isolation from the external environment, and to prevent the curved surface heating device from being affected by temperature and humidity, thereby increasing the stability of the bonding layer20, the conductive layer30, and the temperature control insulation layer40.

Wherein, the pattern of the insulation layer50is not limited and can be a thin film layer that envelops the multi-layer structure of the bonding layer20, the conductive layer30, and/or the temperature control insulation layer40using methods such as coating, pad printing, reprinting, transfer printing, in-mold printing, 3D printing, inkjet printing, gravure printing, and the like. The insulation layer50may also be a shell that is bonded to the protective layer10through adhesive bonding or structural assembly.

Wherein, the insulation layer50may be a resin mixture commonly used as a protective adhesive, or may be made of plastic or glass; preferably, the insulation layer50is made of plastic materials such as polycarbonate (PC), polypropylene (PP), or polyethylene (PE).

Referring toFIGS.3and4, the present invention further provides a method of manufacturing the flexible 3D pattern element to form the conductive layer30and/or the temperature control insulation layer40on the curved surface structure. The steps include:

Step S1: Preparing the protective layer10. The protective layer10is the curved panel, which can be completed by any current process for forming a curved surface structure.

Step S2(optional): Coating or bonding the bonding layer20onto the concave surface101of the protective layer10.

Step S3: Transferring the conductive layer30to the concave surface101of the protective layer10or to the bonding layer20. The detailed steps are described below using the protective layer10and the conductive layer30as examples:

Preparing a base70in advance and placing the conductive layer30on an upper surface701of the base70. A carrier71is formed according to the shape of the curved surface of the protective layer10. In this embodiment, the shape of the carrier71corresponds to the shape of the concave surface101of the protective layer10.

Applying a pressure to the carrier71toward the upper surface701to cover the surface of the conductive layer30with the carrier71, and at least a portion of the carrier71contacts the upper surface701of the base70, so that the carrier71is attached to the conductive layer30. Wherein the method by which the conductive layer30is attached to the carrier71is not limited, and the conductive layer30may be attached to the surface of the carrier71by the method of electrostatic adsorption, inherent tackiness of the conductive layer30, or vacuum adsorption, etc.

Wherein, the carrier71is a block with elastic deformation properties, which facilitates the transfer of the conductive layer30to withstand pressure and helps the conductive layer30to adhere.

The carrier71then brings the conductive layer30against the concave surface101of the protective layer10so that when the carrier71leaves the concave surface101of the protective layer10again, the conductive layer30remains on the concave surface101of the protective layer10to complete the transfer step of the conductive layer30.

Wherein, the upper surface701of the base70is concavely provided with a conductive recess72, and the conductive layer30is placed in the conductive recess72. The conductive layer30corresponds to the depth of the conductive recess72to form a conductive pattern32with a thickness, and at the same time, when attached to the carrier71, a corresponding curved surface structure is formed.

Wherein, when the conductive layer30is the conductive adhesive, and the conductive adhesive is filled into the base70, a scraper73is used to evenly distribute the conductive adhesive on the base70and scrape off the excess conductive adhesive. Thus, the conductive adhesive forms a three-dimensional and stable thickness.

Wherein, the conductive layer30can be mixed with the adhesive of the bonding layer20prior to being placed on the base70for performing the flexible 3D pattern element forming method.

Wherein, the conductive adhesive can be attached to the carrier71in a solidified or semi-solidified state, such that the conductive adhesive can maintain the conductive pattern32corresponding to the conductive recess72on the carrier71.

It should be noted that the carrier71can correspond to the corresponding curvature of the vehicle lamp shell A, so that the carrier71can be applied to the vehicle lamp shells A with different curvatures. Preferably, the carrier71can also be applied to any workpieces with curvature, such as windshields of automobiles or motorcycles.

The application scope of the flexible 3D pattern element forming method provided by the present invention is wide, which can be used for various workpieces with different curvature, especially for the workpieces having larger curvature, and to achieve continuous printing effect, thereby enhancing process efficiency.

It should be noted that the flexible 3D pattern element forming method differs from conventional pad printing processes, which usually involve multiple steps such as platemaking, printing, and transfer printing, leading to complex procedures and high time costs, and the conventional pad printing processes can only be applied to thin films or paints. In contrast, in this method, the conductive layer30is first formed using the conductive adhesive corresponding to the base70, and then the conductive layer30is attached to the concave surface101of the protective layer10. With this method, a conductive layer30can be transfer printed with a thickness that is not possible with the conventional methods. If the conductive layer30does not reach the desired thickness, the curved surface heating device is susceptible to wear and may not provide the desired electrothermal effect in long-term use. In addition, when the conventional pad printing methods are applied to large-area structures, uneven ink deposition may occur and affect product quality.

The flexible 3D pattern element forming method provided by the present invention is not only suitable for workpieces with curvature, but also because the conductive adhesive is first poured into the base70during the manufacturing process, and then the material is evenly distributed within the base70by the scraper72, so that the conductive adhesive can conform to the shape of the base70to form a 3D and stable pattern, solving the problems that may be encountered in conventional pad printing processing, and greatly improving the yield of the conductive layer30.

Referring toFIG.5. The present invention further provides a second preferred embodiment of the curved surface heating device. The conductive layer30is distributed on the protective layer10in the form of linear conductive patterns32. The conductive patterns32can be a type of mesh distribution, and such mesh distribution can ensure that when the electric current passes through, the electric current can flow uniformly and produce uniform heating effects throughout the conductive layer30. Preferably, the spacing between adjacent lines of the linear conductive layer30can be adjusted according to the requirements of the application of the curved surface heating device so that the curved surface heating device can achieve different heating effects. For example, a smaller line spacing can provide higher conductivity so that the curved surface heating device can flow smoothly and transmit the electric current after being electrified. Wherein the preferred thickness of the conductive layer30is 10 micrometers (μm), which can provide an appropriate resistance value so that the electric current can effectively produce heating effects when passing through.

Wherein, the temperature control insulation layer40may also overlap with the conductive layer30in the form of the conductive pattern32, without limitation.

Referring toFIG.6. The present invention further provides a third preferred embodiment of the curved surface heating device. At least one conductive wire30A can be added between the conductive layer30and the temperature control insulation layer40, so that the electric current can flow to the conductive layer30to produce heating effects. Preferably, the conductive wire30A is a material having dielectric and flexibility.

Furthermore, this embodiment includes two conductive wires30A, each of which includes two electrode points30B and two fixing members30C. The two conductive wires30A are connected and fixed to the conductive layer30via the two electrode points30B. The method of fixing the two electrode points30B to the conductive layer30may include fixing elements, such as low-temperature solder paste or fixed terminal blocks, to reduce the effect on the conductivity of the conductive layer30. Preferably, the conductive wire30A can be tightly connected to the conductive layer30by direct pressure or by using temperature melting, for example, by using a conductive double-sided adhesive to directly attach the conductive wire30A to the conductive layer30. By the adhesive properties of the conductive double-sided adhesive, the conductive wire30A is firmly fixed to the conductive layer30, thereby preventing the conductive wire30A from falling off due to shaking or vibration during driving of the vehicle, thereby improving the usability of the conductive wire30A. At the same time, by directly fixing the conductive wire30A to the conductive layer30, a situation in which the electrode surface printing layer falls off due to repeated switching of the vehicle lamp components B after the vehicle lamp component B is activated, resulting in an unstable power supply or an inability to supply power, can also be avoided.

It should be noted that the two conductive wires30may be a flexible circuit board having the characteristics of small volume, easy connection, wear resistance, and high precision, and because of strong flexibility, the flexible circuit board can be widely used, such as in the vehicle lamp shell A, and can be well fitted with the vehicle lamp shell A; preferably, the flexible circuit board includes flexible flat cables (FFC) and flexible printed circuits (FPC).

The two fixing members30C are respectively located at one end of the two opposite electrode points30B, and the two conductive wires30A are fixed to a substrate by the two fixing members30C so that the two conductive wires30A are free from shaking or vibration to cause loosening during driving of the vehicle; wherein the two fixing members30C include conductive double-sided adhesive, low-temperature solder paste, or fixed terminal blocks and other fixing elements having fixing effects.

Wherein, the substrate may include a circuit board, which is connected to the power supply device, when the two conductive wires30A are fixed to the circuit board by the two fixing members30C and connected to the power supply device via the circuit board, the electric current flows from the power supply device to the conductive wires30A, then flows into the conductive layer30through the conductive wires30A, and finally achieves heating and temperature rise through the conductive layer30.

Preferably, the two conductive wires30A can be disposed to extend from the edge of the vehicle lamp shell A toward the vehicle lamp component B and then fixed to the substrate by the two fixing members30C.

It is worth mentioning that the two ends of the linear conductive layer30are not directly connected, but are connected to the two electrode points30B, respectively, forming a unidirectional current loop. When the power supply device is activated, the current is sequentially transmitted from the circuit board to the fixing member30C, then to the electrode point30B on the conductive wire30A, and finally to the conductive layer30through the conductive wire30A; since the conductive layer30is evenly distributed in a linear shape on the protective layer10and the bonding layer20and is connected in the unidirectional current loop, the conductive layer30can generate uniform heating effects after being electrified, thereby preventing local overheating or uneven heating of the conductive layer30.

Referring toFIGS.7and8andFIGS.5and6, a third preferred embodiment of the present invention is shown. In order to clearly illustrate the practical effects and achievements of this embodiment,FIGS.5and6only describe the combination relationship of the protective layer10, the conductive layer30, the conductive wire30A, the electrode point30B, and the fixing member30C as a schematic representation. Any combination method that can achieve the same effect and purpose of the curved surface heating device is covered in this specification.

The method in which the two conductive wires30A are connected to the conductive layer30via the two electrode points30B includes, but is not limited to, fixing the two conductive wires30A to the center of the conductive layer30in the protective layer10via the two electrode points30B; for example, the two conductive wires30A may also be fixed to the periphery of the conductive layer30in the protective layer10via the two electrode points30B. In this way, when the two conductive wires30A are installed in workpieces having complex internal structures, the two conductive wires30A are tightly attached and installed along the internal structure of the workpiece in the same direction, which reduces the impact of the two conductive wires30A on other components inside the workpiece.

When the curved surface heating device is applied to the vehicle lamp shell A, the edge of the protective layer10extends with a fastening structure11to be fastened with a lamp holder60. When the vehicle lamp component B is electrified and emits light, the light emitted from the vehicle lamp component B passes through the vehicle lamp shell A.

The curved surface heating device and its manufacturing method provided by the present invention use the flexible 3D pattern element forming method to produce workpieces with curved and deformable surfaces, which can be widely used in various materials and products, especially for workpieces with larger curvatures, surfaces, or continuous printing requirements for adhesives, coatings, etc. Furthermore, with the properties of the temperature control insulation layer40material, the curved surface heating device has the effect of temperature control and temperature maintenance, reducing the occurrence of uneven heating of the curved surface heating device. At the same time, by directly fixing the two conductive wires30A to the conductive layer30, the repeated switching impact on the vehicle lamp components after the vehicle lamp component is activated can be reduced, so that the electrode surface printing layer is less likely to fall off or become detached, thereby increasing the service life of the curved surface heating device.