Heater

Abstract

To provide a heater capable of responding to a wide range of requirements depending on a use environment.SOLUTION: A heater includes: a first flexible printed wiring board 100 having a heater circuit formed of a metal; and a second flexible printed wiring board 200 having an energization circuit for energizing the heater circuit. The heater circuit and the energization circuit are anisotropically conductively connected to each other, so that it is possible to meet both of the requirements required for the heater circuit portion and the requirements required for the energization circuit portion, and it is possible to meet a wide range of requirements according to a use environment.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a heater using a flexible printed wiring board.

Background Art

[0002] Conventionally, in automobiles, heaters are mounted not only around the driver's seat such as the front glass, but also around pipes, batteries, lights, etc., and the number of mounting locations for heaters is increasing. Of course, not only in automobiles, but also in various devices, heaters are mounted at various locations. Depending on the mounting location of the heater, the required conditions for the heater are different. As a heater that is easy to apply to the shape of the mounting position, a heater using a flexible printed wiring board is known.

[0003] FIG. 8 is a schematic view of a heater 700 using a flexible printed wiring board according to a conventional example. The heater 700 includes a portion 710 having a heater circuit and a portion 720 having a power supply circuit for supplying power to the heater circuit, and is constituted by a flexible printed wiring board. In general, a connector 730 for connecting to another device is provided at the end of the portion 720 having the power supply circuit. Thus, in the heater 700 using a flexible printed wiring board, since it is more flexible than a heater using a rigid substrate or the like, it is easy to apply to the shape of the mounting position.

[0004] However, even in such a heater, there are advantages and disadvantages depending on the metal materials that make up the heater circuit and the energization circuit. When the metal material is copper, it has excellent flexibility, high solderability, easy connection to electronic components, and easy double-sided and multi-layer formation. On the other hand, when high-temperature heating is required due to its low resistivity, it is necessary to make the wire thinner, and there is a disadvantage that wiring design is difficult because the change in resistivity due to temperature is large. When the metal material is SUS, it has a high resistivity and easy wiring design, but on the other hand, it has disadvantages such as lower flexibility, lower solderability, and difficulty in double-sided and multi-layer formation compared to copper. When the metal material is aluminum, it has high flexibility and a high resistivity, but like SUS, it has disadvantages such as low solderability and difficulty in double-sided and multi-layer formation.

[0005] As described above, depending on the metal materials that make up the heater circuit and the energization circuit provided in the flexible printed wiring board, there are advantages and disadvantages, and there is still room for improvement to widely respond according to the usage environment.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to provide a heater capable of meeting a wide range of requirements according to the usage environment.

Means for Solving the Problems

[0008] The present invention has adopted the following means to solve the above problems.

[0009] That is, the heater of the present invention a first flexible printed wiring board having a heater circuit made of metal, a second flexible printed wiring board having an energization circuit for energizing the heater circuit, and is characterized in that the heater circuit and the energization circuit are anisotropically conductively connected.

[0010] According to the present invention, since the first flexible printed wiring board having the heater circuit and the second flexible printed wiring board having the energization circuit are constituted by separate members, it is possible to meet both the requirements for the heater circuit part and the requirements for the energization circuit part. Further, since the heater circuit and the energization circuit are connected by anisotropic conductive connection, they can be appropriately connected regardless of the types of these metal materials.

[0011] It is preferable that the metal material of the heater circuit and the metal material of the energization circuit are different materials.

[0012] Thereby, even if the requirements for the heater circuit part and the requirements for the energization circuit part are different, it is possible to correspond to each of these requirements.

[0013] At the anisotropically conductively connected portion, it is preferable that the first flexible printed wiring board and the second flexible printed wiring board are buried inside the sealing member together.

[0014] Thereby, the anisotropically conductively connected portion can be more reliably protected.

[0015] It is preferable to include electronic components mounted on the first flexible printed wiring board.

[0016] The electronic components are preferably connected to a circuit provided on the second flexible printed wiring board.

[0017] In addition, the above configurations can be adopted in combination as much as possible.

Advantages of the Invention

[0018] As described above, according to the present invention, it is possible to meet a wide range of requirements according to the usage environment.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0020] Hereinafter, with reference to the drawings, modes for carrying out this invention will be exemplarily described in detail based on examples. However, dimensions, materials, shapes, relative arrangements, etc. of the components described in this example are not intended to limit the scope of this invention only to those, unless otherwise specifically described.

[0021] (Embodiment) With reference to FIGS. 1 and 2, a heater according to an embodiment of the present invention will be described. FIG. 1 is a schematic diagram of a heater according to an embodiment of the present invention, and (a) shows a state before joining each member. FIG. (a) is a plan view, and FIG. (b) is a side view of the heater. FIG. 2 is a schematic view showing an example of use of the heater according to the embodiment of the present invention.

[0022] The heater 10 includes a first flexible printed wiring board 100 having a heater circuit made of metal, and a second flexible printed wiring board 200 having an energization circuit for energizing the heater circuit. A connector 250 is connected to an end of the second flexible printed wiring board 200.

[0023] The heater circuit on the first flexible printed wiring board 100 and the energization circuit on the second flexible printed wiring board 200 are anisotropically conductively connected (ACF connection). This will be described more specifically. In the heater circuit on the first flexible printed wiring board 100, at least the portion to be anisotropically conductively connected is exposed. Similarly, in the energization circuit on the second flexible printed wiring board 200, at least the portion to be anisotropically conductively connected is exposed. By opposing a part of these heater circuits and a part of the energization circuit and sandwiching an anisotropic conductive film (ACF) 300 and applying pressure while heating, anisotropic conductive connection can be achieved.

[0024] <Advantages of the heater according to the present embodiment> According to the heater 10 according to the present embodiment, the first flexible printed wiring board 100 having the heater circuit and the second flexible printed wiring board 200 having the energization circuit are constituted by separate members. Therefore, it is possible to meet both the requirements for the heater circuit part and the requirements for the energization circuit part. Further, since the heater circuit and the energization circuit are connected by anisotropic conductive connection, they can be appropriately connected regardless of the types of these metal materials.

[0025] In the heater 10 according to this embodiment, it is particularly effective when the metal material of the heater circuit and the metal material of the energization circuit are made of different materials. Thereby, even if the requirements for the heater circuit part and the requirements for the energization circuit part are different, each of these requirements can be satisfied.

[0026] When the metal material constituting the circuit is copper, it has excellent flexibility, high solderability, easy connection to electronic components, and easy double-sided and multi-layer formation. Therefore, when the shape of the location where the first flexible printed wiring board 100 is attached is complex such as being curved, or when it is desired to directly attach electronic components such as sensors (thermistors, etc.) or fuses, or when it is desired to add a capacitance sensor function by multi-layer formation, it is effective to use copper as the material of the heater circuit. Also, when the second flexible printed wiring board 200 is bent and arranged along the outer wall of the device or arranged along the gaps of a complex shape inside the device, or when it is difficult to attach electronic components to the heater circuit and electronic components are to be attached to the energization circuit, it is effective to use copper as the material of the energization circuit.

[0027] When the metal material constituting the circuit is SUS or aluminum, the resistivity is high and wiring design is easy. Therefore, when control at high temperatures is required, it is effective to use SUS or aluminum as the material of the heater circuit. In the case of aluminum, since it also has excellent flexibility, it is also effective when it is desired to bend and use the first flexible printed wiring board 100 or the second flexible printed wiring board 200.

[0028] As described above, according to the heater 10 according to this embodiment, it is possible to meet a wide range of requirements according to the usage environment.

[0029] Referring to FIG. 2, a usage example of the heater 10 according to this embodiment will be described. This usage example In this case, the first flexible printed wiring board 100 is attached to the device 600 to be heated, and the second flexible printed wiring board 200 is arranged so as to be bent along the outer wall of the device 600. Note that a connector 250 is connected to a control device 650 for controlling the heating of the heater 10 or acquiring detection information from a sensor mounted on the first flexible printed wiring board 100. In this usage example, since the first flexible printed wiring board 100 is attached to a flat portion of the device 600, when high-temperature control is required, it is desirable to use SUS or aluminum as the material of the heater circuit. Further, since the second flexible printed wiring board 200 is used in a bent state, it is desirable to use copper or aluminum as the material of the energization circuit. Note that when SUS or aluminum is used as the material of the heater circuit and electronic components are mounted on the first flexible printed wiring board, it is difficult to directly attach the electronic components to the heater circuit. Therefore, copper is used as the material of the energization circuit, and a part of the second flexible printed wiring board is branched so that the electronic components can be mounted on the first flexible printed wiring board (see Example 2).

[0030] Note that in the present invention, heaters in which the metal material of the heater circuit and the metal material of the energization circuit are necessarily made of the same material are not necessarily excluded. Hereinafter, more specific examples will be described.

[0031] (Example 1) Referring to FIGS. 3 to 6, the heater according to this embodiment will be described. Since the basic configuration is as described in the embodiment, the same reference numerals are given to the same components, and the description thereof will be omitted as appropriate. FIG. 3 is a schematic diagram of the heater according to Embodiment 1 of the present invention, (a) is a plan view showing the state before joining each member, (b) is a schematic cross-sectional view of the second flexible printed wiring board (cross-sectional view AA in (a)), (c) is a schematic cross-sectional view of the anisotropic conductive film (cross-sectional view BB in (a)), and (d) is a schematic cross-sectional view of the first flexible printed wiring board (cross-sectional view CC in (a)). FIG. 4 is a schematic diagram of the heater according to Embodiment 1 of the present invention, (a) is a plan view of the heater, and (b) is a schematic cross-sectional view of the heater (cross-sectional view DD in (a)). FIG. 5 is a schematic diagram of the heater according to a modified example of Embodiment 1 of the present invention, (a) is a plan view of the heater, and (b) is a schematic cross-sectional view of the heater (cross-sectional view EE in (a)). FIG. 6 is a schematic diagram showing various examples of the first flexible printed wiring board.

[0032] <Configuration of Heater> The heater 10 includes a first flexible printed wiring board 100 and a second flexible printed wiring board 200. The first flexible printed wiring board 100 includes a base film 110, a heater circuit 120 formed of a metal (such as a thin metal film), and a cover film 130 for protecting the heater circuit 120. The cover film 130 is bonded to the base film 110 so as to sandwich the heater circuit 120 with an adhesive layer 140. The base film 110 and the cover film 130 are made of an insulating resin material such as polyimide or polyethylene naphthalate. For the metal material of the heater circuit 120, as described in the embodiment, an appropriate material can be selected according to the requirements of the usage location. The second flexible printed wiring board 200 includes a base film 210, an energization circuit 220 formed of a metal (such as a thin metal film), and a cover film 230 for protecting the energization circuit 220. The cover film 230 is bonded to the base film 210 so as to sandwich the energization circuit 220 with an adhesive layer 240. The base film 210 and the cover film 230 are made of an insulating resin material such as polyimide or polyethylene naphthalate. For the metal material of the energization circuit 220, as described in the embodiment, an appropriate material can be selected according to the requirements of the usage location.

[0033] In this embodiment, by providing an opening in a part of the cover film 130 in the first flexible printed wiring board 100, a part of the heater circuit 120 is exposed. Similarly, by providing an opening in a part of the cover film 230 in the second flexible printed wiring board 200, a part of the energization circuit 220 is exposed. By facing these exposed portions and sandwiching an anisotropic conductive film 300 and heating while applying pressure, a part of the heater circuit 120 and a part of the energization circuit 220 can be anisotropically conductively connected.

[0034] The anisotropic conductive film 300 has a structure in which a plurality of conductive particles 310 are dispersed inside a thermosetting resin 320. Thus, when the anisotropic conductive film 300 is sandwiched between the first flexible printed wiring board 100 and the second flexible printed wiring board 200 and heated while being pressed, a part of the thermosetting resin 320 is in a molten state, and the conductive particles 310 are sandwiched and pressed between the heater circuit 120 and the energization circuit 220. As a result, the heater circuit 120 and the energization circuit 220 can be energized through the conductive particles 310. Further, when the thermosetting resin 320 hardens, a part of the first flexible printed wiring board 100 and a part of the second flexible printed wiring board 200 are joined together.

[0035] With the heater 10 configured as described above, the effects described in the embodiment can be obtained.

[0036] <Modification> As shown in the modification of FIG. 5, at the anisotropically conductive connection site, a configuration can be adopted in which the first flexible printed wiring board 100 and the second flexible printed wiring board 200 are each buried inside a sealing member 400 made of a resin material or the like. By adopting such a configuration, the insulation of the anisotropically conductive connection portion can be further enhanced, and waterproofness can also be achieved. For example, by using the heater shown in FIG. 4 as an insert part and molding the sealing member 400 by insert molding, the heater 10 shown in FIG. 5 can be obtained.

[0037] <Various examples of the first flexible printed wiring board> Referring to FIG. 6, various examples of the first flexible printed wiring board 100 will be described. Note that the same components as those in the above-described Example 1 are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0038] In the case of the first flexible printed wiring board 100 shown in FIG. 6(a), the metal material of the heater circuit 120a is made of copper. In this case, the solderability is high. Therefore, by providing an opening in a part of the cover film 130 and exposing a part of the heater circuit 120a, and soldering electronic components 500 such as sensors and fuses, the electronic components 500 can be directly mounted on the first flexible printed wiring board 100.

[0039] In the case of the first flexible printed wiring board 100 shown in FIG. 6(b), as shown in the above embodiment, a configuration is adopted in which the heater circuit 120a is provided only on one surface side of the base film 110. On the other hand, in the case of the first flexible printed wiring board 100 shown in FIG. 6(c), a configuration is adopted in which the heater circuits 120a are provided on both surface sides of the base film 110, respectively. In this first flexible printed wiring board 100, since metal foils are provided on both surfaces of the base film 110, it is desirable to adopt copper, which is easy to be made double-sided, as the metal material. And when copper is adopted as the metal material of the energization circuit 220 of the second flexible printed wiring board 200 joined to this first flexible printed wiring board 100, the metal materials of the heater circuit 120a and the energization circuit 220 are the same material. Thus, in this embodiment, even when the metal materials of the heater circuit 120a and the energization circuit 220 are the same material, it can be suitably applied.

[0040] The first flexible printed wiring board 100 shown in FIG. 6(c) has a capacitance sensor function. In this first flexible printed wiring board 100, a heater circuit 120a is provided on one surface side of the base film 110, and a metal foil 120b is provided over the entire other surface side. By using this metal foil 120b as a GND electrode and using a metal foil 120c connected to the heater circuit 120a on one surface side of the base film 110 as a detection electrode, it can also function as a capacitance sensor. Also in this first flexible printed wiring board 100, since the metal foil is provided on both surfaces of the base film 110, it is desirable to adopt copper, which is easy to form on both sides, as the metal material.

[0041] In addition, the various examples shown in FIG. 6 are applicable not only to the above-described embodiments but also to the modified examples shown in FIG. 5. Also, the various examples shown in FIG. 6 are merely examples of the first flexible printed wiring board 100.

[0042] (Embodiment 2) FIG. 7 shows Embodiment 2 of the present invention. In this embodiment, a configuration is shown when an electronic component is attached to a second flexible printed wiring board. The same components as those in the above-described embodiment and Embodiment 1 are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. FIG. 7 is a schematic diagram of a heater according to Embodiment 2 of the present invention, (a) is a plan view of the second flexible printed wiring board, and (b) is a plan view of the heater.

[0043] When the metal material of the heater circuit 120 of the first flexible printed wiring board 100 is made of SUS or aluminum, it is difficult to attach electronic components because of its low solder connection property. Therefore, in this embodiment, a configuration is adopted in which an electronic component such as a thermistor can be attached to the second flexible printed wiring board 200 by using copper as the metal material of the energization circuit 220 of the second flexible printed wiring board 200. Specifically, a plurality of branch portions 200X are provided on the second flexible printed wiring board 200, and electronic components 500 are attached to the tips thereof. As a result, the electronic components 500 can be adhered to the surface of the cover film 130 on the first flexible printed wiring board 100 with a double-sided tape or an adhesive. Thereby, the electronic components 500 can be mounted on the first flexible printed wiring board 100.

Explanation of Signs

[0044] 10: Heater 100: First flexible printed wiring board 110: Base film 120, 120a: Heater circuit 120b, 120c: Metal foil 130: Cover film 140: Adhesive layer 200: Second flexible printed wiring board 200X: Branch portion 210: Base film 220: Energization circuit 230: Cover film 240: Adhesive layer 250: Connector 300: Anisotropic conductive film 310: Conductive particles 320: Thermosetting resin 400: Sealing member 500: Electronic component 600: Device 650: Control device

Claims

1. A first flexible printed wiring board having a heater circuit composed of metal, A second flexible printed wiring board having a power supply circuit for supplying power to the heater circuit, Comprising, A heater characterized in that the heater circuit and the power supply circuit are anisotropically conductively connected.

2. The heater according to claim 1, characterized in that the metal material of the heater circuit and the metal material of the power supply circuit are different materials.

3. The heater according to claim 1 or 2, characterized in that at the anisotropically conductively connected portion, the first flexible printed wiring board and the second flexible printed wiring board are both buried inside a sealing member.

4. The heater according to claim 1 or 2, characterized by comprising electronic components mounted on the first flexible printed wiring board.

5. The heater according to claim 4, characterized in that the electronic component is connected to a circuit provided on the second flexible printed wiring board.

Images