Connection structure

Abstract

To implement an independent electrical connection in a simple structure in a connection structure of each fuel battery cell.SOLUTION: A connection structure for forming independent electrical connections of a plurality of cells constituting a fuel battery stack comprises: a plurality of support members attached to the plurality of cells; an anisotropic conductive member which is mounted over the plurality of support members and in contact with each of the plurality of cells; and a substrate which is mounted over the plurality of support members and holds the anisotropic conductive member with the plurality of cells. In the anisotropic conductive member, a plurality of conductive paths extending in a direction, in which the plurality of cells is opposed with the substrate, and electrically insulated from each other is arrayed in a stacking direction of the plurality of cells.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The technology disclosed in this specification relates to a connection structure for forming independent electrical connections to each of a plurality of cells constituting a fuel cell stack.

Background Art

[0002] Patent Document 1 describes a fuel cell. In this fuel cell, a cell monitor is provided to monitor the power generation state of the fuel cell stack.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to connect a device such as a cell monitor to a fuel cell stack, a connection structure for forming independent electrical connections to each of a plurality of cells constituting the fuel cell stack is required. This specification provides a technology capable of realizing such a connection structure with a simple structure.

Means for Solving the Problems

[0005] The technology disclosed in this specification is embodied in a connection structure for forming independent electrical connections for each of a plurality of cells (specifically, fuel cell cells) that make up a fuel cell stack. This connection structure includes a plurality of support members respectively attached to the plurality of cells, an anisotropic conductive member attached across the plurality of support members and contacting each of the plurality of cells, and a substrate attached across the plurality of support members and sandwiching the anisotropic conductive member between the plurality of cells. In the anisotropic conductive member, a plurality of conductive paths each extending along the direction facing the plurality of cells and electrically insulated from each other are arranged along the stacking direction of the plurality of cells.

[0006] In the above configuration, an anisotropic conductive member is disposed between the plurality of cells and the substrate. In the anisotropic conductive member, a plurality of independent conductive paths are arranged along the stacking direction of the plurality of cells. According to such a configuration, the plurality of cells can be individually connected to a plurality of contacts provided on the substrate using a single or a small number of anisotropic conductive members.

[0007] In one embodiment of the present technology, the substrate may be a flexible substrate. At least one protrusion extending through the flexible substrate may be provided on each of the plurality of support members. And a pressing member for pressing the flexible substrate toward the anisotropic conductive member may be attached to the at least one protrusion. According to such a configuration, since the flexible substrate has flexibility, even when there are dimensional errors between the plurality of cells, each of the plurality of cells and the substrate can be surely brought into contact with the anisotropic conductive member.

[0008] In the above-described embodiment, each of the plurality of support members may include a protrusion located on one side of the anisotropic conductive member and a protrusion located on the other side of the anisotropic conductive member as the at least one protrusion described above. According to such a configuration, at two locations straddling the anisotropic conductive member, the support member and the pressing member are fixed to each other. Thereby, reliable contact between the flexible substrate and the anisotropic conductive member can be achieved.

[0009] In one embodiment of the present technology, slits may be formed in the flexible substrate in accordance with the arrangement of a plurality of support members. According to such a configuration, since the flexible substrate has further flexibility, more reliable contact can be achieved between the flexible substrate and the anisotropic conductive member.

[0010] In one embodiment of the present technology, when the plurality of support members are respectively attached to a plurality of cells, grooves for accommodating the anisotropic conductive member may be formed. In this case, an opening for exposing the cell may be formed on the bottom surface of the groove in each of the plurality of support members. In this way, when the plurality of support members holding the anisotropic conductive member are attached to the plurality of cells independently of each other, even if there are manufacturing errors in the interval between two adjacent cells, reliable contact can be achieved between each of the plurality of cells and the anisotropic conductive member.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

Examples

[0012] Referring to the drawings, the connection structure 2 of the embodiment will be described. The connection structure 2 of this embodiment is not particularly limited, but can be used for connecting a cell monitor in order to monitor the power generation state of the fuel cell stack 11. The connection structure 2 of this embodiment can form independent electrical connections for each of the plurality of fuel cell cells 10 (hereinafter, may be simply referred to as cells 10) that make up the fuel cell stack 11. Note that the connection structure 2 of this embodiment can be adopted, for example, in a fuel cell vehicle (including automobiles, buses, trucks, work vehicles, motorcycles) or a stationary fuel cell device.

[0013] In the fuel cell stack 11, a plurality of cells 10 are stacked and arranged along the X direction. Note that the specific configurations of the cell 10 and the fuel cell stack 11 are not particularly limited. Although it is an example, the cell 10 may use hydrogen gas as the fuel gas and air as the oxidizing gas. Further, the cell 10 may include a membrane electrode gas diffusion layer assembly (MEGA), a support frame, and a pair of separators. In this case, the membrane electrode gas diffusion layer assembly may include an electrolyte membrane, an anode catalyst layer, a cathode catalyst layer, an anode gas diffusion layer, and a cathode gas diffusion layer.

[0014] As shown in FIGS. 1-4, the connection structure 2 includes a plurality of support members 12, an anisotropic conductive member 14, a flexible substrate 16, and a pressing member 18.

[0015] The plurality of support members 12 are respectively attached to the plurality of cells 10. Although not particularly limited, each support member 12 is attached so as to sandwich the upper edge of the cell 10. Each support member 12 includes a clamping portion 12a that clamps the upper edge of the cell 10 and a pair of body portions 12b that extend vertically upward from the clamping portion 12a. A protrusion 12d is formed on the top surface 12c of each body portion 12b. A groove 12e is defined between the pair of body portions 12b. Inside the groove 12e, an opening 12f for exposing the upper edge of the cell 10 is provided in the clamping portion 12a that defines the bottom thereof. When the plurality of support members 12 are respectively attached to the plurality of cells 10, a series of grooves 12e extending along the X direction are formed. The support member 12 is made of an insulating material such as, for example, a resin material.

[0016] The anisotropic conductive member 14 is attached across the plurality of support members 12. Specifically, the anisotropic conductive member 14 is housed in a series of grooves 12e formed by the plurality of support members 12 and has a shape that extends long along the X direction. As described above, each support member 12 is provided with an opening 12f for exposing the upper edge of the cell 10. Thereby, the anisotropic conductive member 14 is in contact with each of the plurality of cells 10 through the opening 12f of the support member 12.

[0017] As shown in FIG. 5, the anisotropic conductive member 14 has a structure in which a conductive layer 14a having conductivity and an insulating layer 14b having insulating properties are alternately laminated along the stacking direction (X direction) of the plurality of cells 10. Thereby, inside the anisotropic conductive member 14, a plurality of conductive paths insulated from each other electrically are arranged along the stacking direction (X direction) of the plurality of cells 10. Each of the plurality of conductive paths (that is, the conductive layer 14a) extends along the facing direction (Z direction) between the plurality of cells 10 and the flexible substrate 16. Here, the thicknesses of the conductive layer 14a and the insulating layer 14b (for example, 10 to 100 micrometers) are sufficiently smaller than the distance between two adjacent cells 10, and one conductive layer 14a does not contact two or more cells 10. Each of the plurality of cells 10 is electrically connected to at least one conductive layer 14a of the anisotropic conductive member 14, but is not electrically connected to other cells 10 via the anisotropic conductive member 14. Although it is an example, the anisotropic conductive member 14 can be configured using a material having the SEC type of 'Shin-Etsu Interconnector' provided by Shin-Etsu Polymer Co., Ltd. or a similar structure.

[0018] The flexible substrate 16 is attached across the plurality of support members 12 and sandwiches the anisotropic conductive member 14 between it and the plurality of cells 10. As described above, projections 12d are formed on each of the support members 12. Accordingly, a pair of openings 16a are provided in the flexible substrate 16. The projections 12d of the support member 12 are inserted into the openings 16a of the flexible substrate 16 and extend through the flexible substrate 16.

[0019] On the flexible substrate 16, a plurality of slits 16b are formed in accordance with the arrangement of the plurality of support members 12. Each slit 16b is provided in accordance with the gap between two adjacent support members 12. As a result, on the flexible substrate 16, a plurality of connection pieces 16c divided by the plurality of slits 16b are formed. Each connection piece 16c is disposed on a corresponding one of the support members 12 and is in contact with the anisotropic conductive member 14. Each connection piece 16c is provided with an electrical contact point 16d with the anisotropic conductive member 14. Note that two openings 16a of the flexible substrate 16 described above are provided in each connection piece 16c.

[0020] The pressing member 18 is attached across the plurality of support members 12 and presses the plurality of connection pieces 16c of the flexible substrate 16 toward the anisotropic conductive member 14. As a result, as shown in FIG. 5, the contact point 16d provided in each connection piece 16c comes into contact with at least one conductive layer 14a of the anisotropic conductive member 14 and is electrically connected to the conductive layer 14a. Here, the thicknesses of the conductive layer 14a and the insulating layer 14b of the anisotropic conductive member 14 are sufficiently smaller than the distance between two adjacent contact points 16d, and one conductive layer 14a does not come into contact with two or more contact points 16d. As a result, each contact point 16d provided on the flexible substrate 16 is electrically connected to only a corresponding one of the plurality of cells 10 via at least one conductive layer 14a of the anisotropic conductive member 14.

[0021] The specific configuration of the pressing member 18 is not particularly limited. Although it is an example, in the pressing member 18 of the present embodiment, a pair of grooves 18a extending along the X direction are provided on the bottom surface, and a pair of protrusions 12d of each support member 12 are engaged with the pair of grooves 18a. In each support member 12, the pair of protrusions 12d are located on both sides with the anisotropic conductive member 14 interposed therebetween. According to such a configuration, the support member 12 and the pressing member 18 are fixed to each other at two locations straddling the anisotropic conductive member 14. As a result, reliable contact can be achieved between the flexible substrate 16 and the anisotropic conductive member 14.

[0022] Note that the pressing member 18 is not necessarily required. For example, the flexible substrate 16 in this embodiment can be replaced with a rigid substrate, for example. In this case, if the rigid substrate has sufficient rigidity, even when the rigid substrate is directly fixed to the support member 12, reliable contact can be achieved between the rigid substrate and the anisotropic conductive member 14.

[0023] In the connection structure 2 of this embodiment, the anisotropic conductive member 14 is disposed between the plurality of cells 10 and the flexible substrate 16. In the anisotropic conductive member 14, a plurality of conductive layers 14a (an example of a conductive path), which are independent of each other, are arranged along the stacking direction of the plurality of cells 10. The thicknesses of the conductive layer 14a and the insulating layer 14b are sufficiently smaller than the distance between two adjacent cells 10 or the distance between two adjacent contact points 16d on the flexible substrate 16. Thereby, one conductive layer 14a does not contact two or more cells 10 or two or more contact points 16d. Thereby, each contact point 16d provided on the flexible substrate 16 is electrically connected to only one corresponding cell 10 among the plurality of cells 10 via at least one conductive layer 14a of the anisotropic conductive member 14. Note that the anisotropic conductive member 14 may be single or may be divided into two or more.

[0024] In the connection structure 2 of this embodiment, a flexible substrate 16 having flexibility is employed, and a plurality of connection pieces 16c divided by a plurality of slits 16b are formed on the flexible substrate 16. According to such a configuration, since the flexible substrate 16 has further flexibility, reliable contact can be achieved between the flexible substrate 16 and the anisotropic conductive member 14 even when there are dimensional errors between the plurality of cells 10, for example.

[0025] In the connection structure 2 of this embodiment, an independent support member 12 is provided for each of the plurality of cells 10. According to such a configuration, even when there are variations in the thickness dimension and height position (position in the Z direction) among the plurality of cells 10, the support member 12 can be correctly attached to each cell 10 without being affected by it. And for the anisotropic conductive member 14, since its base material is rubber or resin, when there are variations in the thickness dimension and height position among the plurality of cells 10, it can be deformed flexibly accordingly.

[0026] As described above, the embodiments of the present technology have been described in detail, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Also, the technology illustrated in this specification or the drawings achieves a plurality of purposes simultaneously, and achieving one of those purposes itself has technical utility.

Explanation of Reference Numerals

[0027] 2: Connection structure, 10: Fuel cell, 11: Fuel cell stack, 12: Support member, 14: Anisotropic conductive member, 15: Conductive path, 16: Flexible substrate, 18: Pressing member

Claims

1. A connection structure for forming independent electrical connections for each of a plurality of cells constituting a fuel cell stack, a plurality of support members respectively attached to the plurality of cells, an anisotropic conductive member attached across the plurality of support members and in contact with each of the plurality of cells, a substrate attached across the plurality of support members and sandwiching the anisotropic conductive member between the substrate and the plurality of cells, comprising: in the anisotropic conductive member, a plurality of conductive paths each extending in a direction facing the plurality of cells and the substrate and electrically insulated from each other are arranged along the stacking direction of the plurality of cells, a connection structure.

2. The substrate is a flexible substrate, at least one protrusion extending through the flexible substrate is provided on each of the plurality of support members, a pressing member for pressing the flexible substrate toward the anisotropic conductive member is attached to the protrusions of the plurality of support members. The connection structure according to Claim 1.

3. Each of the plurality of support members includes, as the at least one protrusion, a protrusion located on one side of the anisotropic conductive member and a protrusion located on the other side of the anisotropic conductive member. The connection structure according to Claim 2.

4. Slits are formed in the flexible substrate in accordance with the arrangement of the plurality of support members. The connection structure according to Claim 2 or 3.

5. When the plurality of support members are respectively attached to the plurality of cells, grooves for accommodating the anisotropic conductive member are formed, an opening for exposing the cell is formed in the bottom surface of the groove in each of the plurality of support members. The connection structure according to Claim 1.

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