Film type radiant heater

Abstract

The invention relates to a film type radiant heater. Specifically, the present invention relates to a thin-film-type radiant heater capable of reducing manufacturing costs by providing a printed electrode, ensuring a sufficient heat generation area, increasing the allowable current range of the electrode, and reducing hot-spot phenomena, thereby enabling efficient heat generation.

Description

Technical Field

[0001] The present invention relates to a thin film type radiation heater. Specifically, the thin film type radiation heater can reduce manufacturing costs by providing printed electrodes, and can ensure sufficient heating area while increasing the allowable current range of the electrodes and reducing hot-spot phenomena, thereby achieving efficient heating. Background Art

[0002] A radiant heater refers to a heating device that utilizes radiant heat from a heat source and can be applied to various fields such as construction, agriculture, medical treatment, beauty, and automobiles. In particular, a thin-film radiant heater that has excellent flexibility and bendability and can be applied to surfaces of various shapes can be applied to the position closest to the driver or passenger, for example, in front of the driver's or passenger's knees, to increase the driving convenience of car drivers in winter.

[0003] Figure 1 is a diagram schematically showing a cross-sectional structure of a conventional thin-film type radiant heater. Figure 2 Show Figure 1 Cross-sectional view along line AA′.

[0004] like Figure 1 and Figure 2 As shown, the existing thin film radiation heater may include: an electrode wiring pattern 20, including a pair of electrodes on the upper surface of the base substrate 10, and the pair of electrodes have different polarities from each other; one or more heating elements 30, connected to the electrode wiring pattern 20; and a protective cover (Cove r) 40, used to protect the electrode wiring pattern 20 and the heating element 30 from the outside.

[0005] In this existing thin film type radiation heater, the electrode wiring pattern 20 is formed by etching the copper foil (Cu foil) laminated on the film. Since the price of the film laminated with copper foil is relatively high, a solution is being sought for forming the electrode wiring pattern 20 by printing metal paste on the base substrate 10 by printing methods such as screen printing, gravure printing, roll-to-roll gravure printing, comma coating, roll-to-roll comma coating, flexographic printing, stamping and offset printing, and then drying and curing the metal paste at 100 to 180°C.

[0006] Figure 3 A cross-sectional view showing an embodiment of forming a printed electrode in a conventional thin film type radiant heater, Figure 4 A cross-sectional view showing still another embodiment of forming a printed electrode in a conventional thin-film radiant heater.

[0007] Specifically, if Figure 3As shown, after printing one or more heating elements 30 on the upper surface of the base film 10, electrodes with different polarities are printed at both ends of each of the heating elements 30 to form the electrode wiring pattern 20, or, as shown in FIG. Figure 4 As shown, after printing electrodes on the upper surface of the base film 10 to form the electrode wiring pattern 20, one or more heating elements 30 may be printed so that both ends thereof are connected to electrodes having different polarities.

[0008] However, the printed electrode has a lower allowable current than the existing etched electrode, and there is a problem that hot spots may occur. In order to increase the allowable current and reduce the hot spots, the width or height of the electrode needs to be increased, but in this case, the area of ​​the heating element will be reduced, resulting in a reduction in the heating area, so there is a problem that sufficient heat generation cannot be achieved.

[0009] Therefore, there is an urgent need for a thin film type radiant heater, which can reduce manufacturing costs by providing printed electrodes, ensure sufficient heating area while increasing the allowable current range of the electrodes and reducing hot-spot phenomena, thereby achieving efficient heating. Summary of the invention

[0010] Problems to be solved by the invention

[0011] An object of the present invention is to provide a thin-film radiant heater capable of reducing manufacturing costs by providing printed electrodes.

[0012] Another object of the present invention is to provide a thin-film radiant heater that can achieve efficient heat generation by increasing the allowable current range of electrodes and reducing hot-spot phenomena while ensuring a sufficient heat generation area.

[0013] Technical solutions to the problem

[0014] In order to solve the above problems, the present invention provides a thin film radiation heater, which includes: a base substrate; an electrode wiring pattern formed on one side of the base substrate, including a pair of electrodes, the pair of electrodes having different polarities from each other; and one or more heating elements, one of its two ends is connected to one electrode of the pair of electrodes, and the other of its two ends is connected to the other electrode of the pair of electrodes; the electrodes include: a primary electrode that does not overlap with the heating element and whose side is separated from or in contact with the heating element; and a secondary electrode that is in contact with the primary electrode and the heating element.

[0015] Here, a thin film type radiation heater is provided, wherein the secondary electrode is formed on the upper portion of the primary electrode, overlaps with the heating element, and forms an overlapping section.

[0016] In addition, a thin film type radiation heater is provided, characterized in that the width of the secondary electrode is defined by the following formula 1.

[0017] [Formula 1]

[0018] Width of secondary electrode = Width of primary electrode + (distance between primary electrode and heating element × 2) + (overlapping distance between heating element and secondary electrode × 2)

[0019] In addition, a thin film radiation heater is provided, characterized in that the width of the primary electrode is more than 45% of the width of the secondary electrode, the distance between the primary electrode and the heating element is more than 0.1 mm, and the overlapping distance between the heating element and the secondary electrode is more than 0.5 mm.

[0020] On the other hand, a thin film radiation heater is provided, which includes: a base substrate; an electrode wiring pattern formed by printing metal paste on one side of the base substrate, including a pair of electrodes, the pair of electrodes having different polarities from each other; and one or more heating elements, one of its two ends being connected to one of the pair of electrodes, and the other of its two ends being connected to the other electrode of the pair of electrodes; the electrodes include: a primary electrode connected to the heating element in a manner that the heating element overlaps with one or more of its ends, and formed by printing metal paste; and a secondary electrode formed by printing metal paste on the upper surface of the primary electrode, which does not overlap with the heating element and whose side is separated from or in contact with the heating element.

[0021] Here, a thin film type radiation heater is provided, wherein the secondary electrode is formed on an upper portion of the primary electrode.

[0022] In addition, a thin film type radiation heater is provided, characterized in that the width of the primary electrode is defined by the following formula 2.

[0023] [Formula 2]

[0024] Width of primary electrode = width of secondary electrode + (distance between secondary electrode and heating element × 2) + (overlapping distance between heating element and primary electrode × 2)

[0025] In addition, a thin film radiation heater is provided, characterized in that the width of the secondary electrode is more than 45% of the width of the primary electrode, the distance between the secondary electrode and the heating element is more than 0.1 mm, and the overlapping distance between the heating element and the primary electrode is more than 0.5 mm.

[0026] On the other hand, a thin film radiation heater is provided, wherein the total height of the electrode is less than 25 μm, and the total height of the electrode includes the height of the primary electrode and the height of the secondary electrode.

[0027] In addition, a thin film type radiation heater is provided, wherein the heating element is formed by printing a metal paste.

[0028] Here, a thin film type radiation heater is provided, characterized in that the metal paste includes a base resin, metal powder and a solvent.

[0029] In addition, there is provided a thin film type radiant heater, wherein the base resin includes at least one selected from the group consisting of epoxy resin, polyester resin, and polyurethane resin.

[0030] In addition, a thin film type radiation heater is provided, characterized in that the metal powder includes powder composed of a metal material, and the metal material is one or more selected from the group consisting of silver (Ag), copper (Cu), aluminum (Al), stainless steel (SUS), nickel (Ni) and their alloys.

[0031] In addition, a thin film type radiation heater is provided, wherein the solvent includes at least one selected from the group consisting of carbitol acetate, ethyl carbitol, butyl carbitol acetate and butyl carbitol.

[0032] In addition, a thin film type radiation heater is provided, characterized in that, based on the total weight of the metal paste, the content of the base resin is 1 to 10 weight %, the content of the metal powder is 75 to 90 weight %, and the content of the solvent is 8.9 to 13 weight %.

[0033] On the other hand, a thin film type radiation heater is provided, characterized in that the heating element is formed by printing a heating paste.

[0034] Here, there is provided a thin film type radiation heater, characterized in that the heat generating paste includes a base resin and conductive particles.

[0035] Effects of the Invention

[0036] The thin-film radiant heater of the present invention has an excellent effect of being able to reduce the manufacturing cost by providing the printed electrodes.

[0037] In addition, the thin film type radiant heater of the present invention has the excellent effect of ensuring a sufficient heating area and improving the allowable current range of the electrode and reducing the hot spot phenomenon by a novel electrode structure, thereby achieving efficient heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A perspective view schematically shows a conventional thin-film type radiant heater.

[0039] Figure 2 Show Figure 1 Cross-sectional view along line AA′.

[0040] Figure 3 A cross-sectional view showing an embodiment of forming a printed electrode in a conventional thin film radiant heater.

[0041] Figure 4 A cross-sectional view showing still another embodiment of forming a printed electrode in a conventional thin-film radiant heater.

[0042] Figure 5 It is a top view of the thin film type radiant heater of the present invention.

[0043] Figure 6 yes Figure 5 Cross-sectional view along line AA′.

[0044] Figure 7 It is a cross-sectional view of still another embodiment of the thin film type radiant heater according to the present invention.

[0045] Figure 8 Graphs showing the current and output relative to the voltage of the thin-film radiant heaters of the embodiment and the comparative example. DETAILED DESCRIPTION

[0046] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be implemented in other ways. On the contrary, the embodiments described herein are provided to make the disclosed contents thorough and complete and to fully convey the ideas of the present invention to those skilled in the art. Throughout the specification, the same reference numerals represent the same constituent elements.

[0047] Figure 5 is a top view of the thin film type radiant heater of the present invention, Figure 6 yes Figure 5 Cross-sectional view along line AA′.

[0048] like Figure 5As shown, the thin film radiation heater of the present invention may include: a base substrate 100; an electrode wiring pattern 200, which is formed by printing a metal paste on one side of the base substrate 100, and includes a pair of electrodes 210, 220, and the pair of electrodes 210, 220 have different polarities from each other; one or more heating elements 300, one of whose two ends is connected to one electrode of the pair of electrodes 210, 220, and the other of whose two ends is connected to the other electrode of the pair of electrodes 210, 220; and an insulating layer 400, which protects the electrode wiring pattern 200 and one or more heating elements 300 from the outside; etc.

[0049] In particular, Figure 6 As shown, the electrode 220 forming the electrode wiring pattern 200 can be composed of a primary electrode 221 and a secondary electrode 222, wherein the primary electrode 221 does not overlap with the heating element 300 and its side is separated from or in contact with the heating element 300, and the secondary electrode 222 is in contact with the primary electrode 221 and the heating element 300. The electrode 210 with different polarities can also be composed of a primary electrode and a secondary electrode like the electrode 220.

[0050] By means of the primary and secondary lamination structure of the electrode, the thin film type radiant heater of the present invention can ensure a sufficient heating area while increasing the allowable current range of the electrode and reducing the hot spot phenomenon, thereby achieving efficient heating.

[0051] Specifically, refer to Figure 6 , the width of the secondary electrode can be defined by the following formula 1.

[0052] [Formula 1]

[0053] Width of secondary electrode = Width of primary electrode + (distance between primary electrode and heating element × 2) + (overlapping distance between heating element and secondary electrode × 2)

[0054] Specifically, the total height of the primary electrode and the secondary electrode can be less than 25 μm, for example, 10 to 25 μm, the width (1) of the primary electrode can be more than 45% of the width (4) of the secondary electrode, the distance (2) between the primary electrode and the heating element can be more than 0.1 mm, for example, 0.1 to 0.5 mm, and the overlapping distance (3) between the heating element and the secondary electrode can be more than 0.5 mm, for example, 0.5 to 1.0 mm.

[0055] When the width of the secondary electrode is lower than the reference, a hot-spot phenomenon will occur because the allowable current range of the electrode is lower than the reference. On the contrary, when it exceeds the reference, the heating area will be unnecessarily reduced, resulting in insufficient heating effect.

[0056] Figure 7 It is a cross-sectional view of still another embodiment of the thin film type radiant heater according to the present invention.

[0057] like Figure 7 As shown, the thin film type radiation heater of the present invention may include: a pair of electrodes having different polarities from each other; and at least one heating element 300' whose two ends are respectively connected to each electrode of the pair of electrodes, and one electrode 220' of the pair of electrodes may include: a primary electrode 221', which is connected to the heating element 300' in a manner that the heating element 300' overlaps with one or more ends thereof, and is formed by printing metal paste; and a secondary electrode 222', which is formed by printing metal paste on the upper surface of the primary electrode 221', does not overlap with the heating element 300' and whose side is separated from or in contact with the heating element 300'.

[0058] Here, refer to Figure 7 , the width of the primary electrode can be defined by the following formula 2.

[0059] [Formula 2]

[0060] Width of primary electrode = width of secondary electrode + (distance between secondary electrode and heating element × 2) + (overlapping distance between heating element and primary electrode × 2)

[0061] Specifically, the total height of the primary electrode and the secondary electrode can be less than 25 μm, for example, 10 to 25 μm, the width (1) of the secondary electrode can be more than 45% of the width (4) of the primary electrode, the distance (2) between the secondary electrode and the heating element can be more than 0.1 mm, for example, 0.1 to 0.5 mm, and the overlapping distance (3) between the heating element and the primary electrode can be more than 0.5 mm, for example, 0.5 to 1.0 mm.

[0062] When the width of the primary electrode is lower than the reference, a hot-spot phenomenon will occur because the allowable current range of the electrode is lower than the reference. On the contrary, when it exceeds the reference, the heating area will be unnecessarily reduced, resulting in insufficient heating effect.

[0063] On the other hand, the base substrate 100 and the insulating layer 400 may include a material selected from polyimide (PI), polyethylene terephthalate (PET), polyacrylonitrile (PAN), polyurethane (PU), silicon, polycarbonate (PC), Teflon, liquid crystal polymer (LCP), polyetheretherketone (PEEK), polyethersulfone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polyallylate, cellulose triacetate (CTA), cellulose acetate propionate (CPA), etc. Preferably, the at least one plastic material selected from the group consisting of polyimide (PI) and the like is included.

[0064] The metal paste forming the electrode can be manufactured by mixing metal powder in a base resin. Here, the base resin may include one or more selected from epoxy resin, polyester resin, polyurethane resin, etc., and the metal powder may include powder composed of metal materials such as silver (Ag), copper (Cu), aluminum (Al), stainless steel (SUS), nickel (Ni), and alloys thereof.

[0065] In addition, in order to adjust the viscosity for improving coating workability, the metal paste may further include one or more solvents selected from carbitol acetate, ethyl carbitol, butyl carbitol acetate, butyl carbitol, etc., and may further include other additives such as wetting dispersants.

[0066] Here, based on the total weight of the metal paste, the content of the base resin may be 1 to 10 weight %, the content of the metal powder may be 75 to 90 weight %, the content of the solvent may be 8.9 to 13 weight %, and the content of other additives may be 0.1 to 2 weight %.

[0067] The metal paste can be produced by mixing a base resin, a solvent, and other additives in advance, mixing and stirring a metal powder while removing air bubbles, and milling the mixture using a 3-roll mill or the like.

[0068] The heating elements 300, 300' can generate heat to above 200°C, preferably above 300°C, and each heating element can be formed by printing a heating paste including a base resin and conductive particles on one side of the base substrate 100 and then drying it so that they can be connected in series or in parallel with each other through the electrode wiring pattern 200.

[0069] The base resin may include epoxy resin, acrylic resin, etc., the conductive particles may include carbon particles such as carbon black, carbon nanotubes, graphite, activated carbon, etc., and may also include metal powders such as silver (Ag), copper (Cu), and nickel (Ni). In particular, since carbon nanotubes have a large aspect ratio, they can not only form a sufficient electrical network with a small amount, but also improve the glass transition temperature and heat resistance of the heating element composition.

[0070] [Example]

[0071] 1. Manufacturing Example

[0072] Make two Figure 3 The cross-sectional structure of the thin film type radiation heater sample of the comparative example and two having Figure 6 The thin film type radiation heater sample of the embodiment of the cross-sectional structure, the total electrode length of each sample is 100mm, which has a top view as shown in Figure 5 The structure shown.

[0073] 2. Resistance evaluation

[0074] Power was applied to each sample of the embodiment and the comparative example and the product resistance and electrode resistance of the thin film type radiant heater were measured 10 times. The measurement results are shown in Table 1 below.

[0075] [Table 1]

[0076]

[0077] As shown in Table 1, it can be confirmed that the thin film type radiation heater of the embodiment of the present invention has an electrode resistance reduced by about 40% and a product resistance reduced by about 6% compared with the thin film type radiation heater of the conventional comparative example, thereby increasing the allowable current of the electrode, and as a result, reducing the hot spot phenomenon.

[0078] 3. Fever evaluation

[0079] A DC (direct current) voltage of 25 V was applied to each of the thin-film radiation heaters of the embodiment and the comparative example, and a thermal imaging camera was used to photograph the heater in the heating state. The temperatures of the heating element 1 at the bottom, the heating element 2 at the top, the electrode 1 with (-) polarity, and the electrode 2 with (+) polarity in the top view were measured. The measurement results are shown in Table 2 below.

[0080] [Table 2]

[0081]

[0082] As shown in Table 2, it was confirmed that the heat generation deviation at a pair of electrodes of the thin film type radiation heater of the embodiment was reduced by about 54%, and the heat generation deviation at the heating element was reduced by about 29% compared with the thin film type radiation heater of the comparative example. It was judged that the improvement in the structure of the electrodes improved the heat generation deviation at a pair of electrodes and one or more heating elements.

[0083] 4. Evaluation of electrical characteristics of thin film radiant heaters

[0084] The current and output power of the thin film type radiant heaters of the embodiment and the comparative example after voltage application were measured. The measurement results are as follows: Figure 8 Here, the total width of one electrode in each of the thin-film radiant heaters of the embodiment and the comparative example is 7 mm, and the total length is 180 mm.

[0085] like Figure 8 As shown, it was confirmed that the thin film type radiant heater of the embodiment had higher current and output relative to voltage than the thin film type radiant heater of the comparative example, and thus it was confirmed that the resistance of the electrode could be improved and the conversion efficiency of electric energy could be improved by such a low resistance electrode.

[0086] The present invention is described with reference to the preferred embodiments of the present invention in this specification, but it is possible for those skilled in the art to make various modifications and changes to the present invention without departing from the scope of the concept and field of the present invention as described in the appended claims. Therefore, as long as the modified embodiments basically include the constituent elements of the claims of the present invention, they should all be deemed to be included in the technical scope of the present invention.

Claims

1. A thin film type radiant heater, wherein: include: base substrate; An electrode wiring pattern is formed on one side of the base substrate and includes a pair of electrodes, wherein the pair of electrodes have different polarities from each other; as well as One or more heating elements, one of the two ends of which is connected to one of the pair of electrodes, and the other of the two ends of which is connected to the other of the pair of electrodes; The electrode comprises: a primary electrode which does not overlap with the heating element and whose side is separated from or in contact with the heating element; as well as The secondary electrode is in contact with the primary electrode and the heating element.

2. The thin film type radiant heater according to claim 1, characterized in that: The secondary electrode is formed on the upper portion of the primary electrode, and overlaps with the heating element to form an overlapping section.

3. The thin film type radiant heater according to claim 2, characterized in that: The width of the secondary electrode is defined by the following formula 1: Formula 1 The width of the secondary electrode = the width of the primary electrode + (the distance between the primary electrode and the heating element × 2) + (the overlapping distance between the heating element and the secondary electrode × 2).

4. The thin film type radiant heater according to claim 3, characterized in that: The width of the primary electrode is 45% or more of the width of the secondary electrode, the distance between the primary electrode and the heating element is 0.1 mm or more, and the overlapping distance between the heating element and the secondary electrode is 0.5 mm or more.

5. A thin film type radiant heater, wherein: include: base substrate; an electrode wiring pattern formed by printing a metal paste on one side of the base substrate, comprising a pair of electrodes, the pair of electrodes having different polarities from each other; and One or more heating elements, one of the two ends of which is connected to one of the pair of electrodes, and the other of the two ends of which is connected to the other of the pair of electrodes; The electrode comprises: a primary electrode connected to the heating element in a manner that the heating element overlaps one or more ends thereof, and formed by printing a metal paste; as well as The secondary electrode is formed by printing a metal paste on the upper surface of the primary electrode, does not overlap with the heating element, and has a side surface separated from or in contact with the heating element.

6. The thin film type radiant heater according to claim 5, characterized in that: The secondary electrode is formed on an upper portion of the primary electrode.

7. The thin film type radiant heater according to claim 6, characterized in that: The width of the primary electrode is defined by the following formula 2: Formula 2 The width of the primary electrode = the width of the secondary electrode + (the distance between the secondary electrode and the heating element × 2) + (the overlapping distance between the heating element and the primary electrode × 2).

8. The thin film type radiation heater according to claim 7, characterized in that: The width of the secondary electrode is 45% or more of the width of the primary electrode, the distance between the secondary electrode and the heating element is 0.1 mm or more, and the overlapping distance between the heating element and the primary electrode is 0.5 mm or more.

9. The thin film radiant heater according to any one of claims 1 to 8, characterized in that The total height of the electrode is less than or equal to 25 μm, and the total height of the electrode includes the height of the primary electrode and the height of the secondary electrode.

10. The thin film type radiant heater according to claim 1, characterized in that: The heating element is formed by printing a metal paste.

11. The thin film type radiant heater according to claim 10, characterized in that: The metal paste includes a base resin, metal powder and a solvent.

12. The thin film type radiant heater according to claim 11, characterized in that: The base resin includes at least one selected from the group consisting of epoxy resin, polyester resin, and polyurethane resin.

13. The thin film type radiant heater according to claim 11, characterized in that: The metal powder includes powder composed of a metal material, and the metal material is one or more selected from the group consisting of silver (Ag), copper (Cu), aluminum (Al), stainless steel (SUS), nickel (Ni), and alloys thereof.

14. The thin film type radiant heater according to claim 11, characterized in that: The solvent includes at least one selected from the group consisting of carbitol acetate, ethyl carbitol, butyl carbitol acetate, and butyl carbitol.

15. The thin film type radiant heater according to claim 11, characterized in that: Based on the total weight of the metal paste, the content of the base resin is 1 to 10 weight %, the content of the metal powder is 75 to 90 weight %, and the content of the solvent is 8.9 to 13 weight %.

16. The thin film type radiant heater according to claim 1, characterized in that: The heating element is formed by printing a heating paste.

17. The thin film type radiant heater according to claim 16, characterized in that: The heat-generating paste includes a base resin and conductive particles.

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