Method for manufacturing separator for fuel cell and method for manufacturing single cell for fuel cell

Abstract

The present disclosure relates to a manufacturing method of a separator for fuel cell and a manufacturing method of a single cell for fuel cell. The manufacturing method of the present invention has a cleaning process in which a first separator is irradiated with laser light at a joining site of the first separator that is intended to be joined with a second separator without joining the first separator with the second separator. In the cleaning process, laser light is irradiated to at least a part of the joining site in such a manner that a plurality of irradiation marks formed by the laser light form a separate irradiation mark pattern arranged separately from each other.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing an separator for fuel cells and a method for manufacturing a single cell for fuel cells. Background Technology

[0002] A fuel cell is constructed by stacking multiple fuel cell units (single cells) with membrane electrode assemblies (MEAs) and two separators sandwiching the MEAs. The separators are connected to other adjacent separators.

[0003] For example, in the technology described in Japanese Patent Application Publication No. 2016-15310, adjacent spacers of stacked single cells are joined together by laser welding. Furthermore, before laser welding, a laser (hereinafter referred to as a "cleaning laser") is irradiated onto the joint and its surroundings to remove any deposits adhering to the joint and its periphery. This is because if deposits remain on the surface of the spacers during joining, such as laser welding, the joint quality may be reduced.

[0004] However, depending on the irradiation method of the cleaning laser, the amount of heat input to the insulating component may be too large, causing the insulating component, which is a thin plate-shaped part, to warp. Summary of the Invention

[0005] This disclosure can be implemented in the following ways.

[0006] (1) According to one aspect of the present disclosure, a method for manufacturing a separator for a fuel cell is provided. The method for manufacturing a separator for a fuel cell includes a cleaning step in which a laser is irradiated at a predetermined joint portion in a first separator that is intended to join with a second separator, without the first separator and the second separator being joined. In the cleaning step, at least a portion of the joint portion is irradiated with the laser so that a plurality of irradiation marks formed by the laser become a separated irradiation mark pattern arranged separately from each other.

[0007] According to this method, at least a portion of the joint is irradiated with laser to form a pattern of separated irradiation marks. Therefore, compared with the case where irradiation is performed to form a pattern of multiple non-separated irradiation marks covering the entire area, the area affected by heat from the irradiated laser (heat-affected area) can be reduced. That is, the amount of heat input caused by laser irradiation of the isolator can be reduced, thereby suppressing the warping of the isolator caused by laser irradiation.

[0008] (2) Alternatively, the configuration may be such that, based on the above method, the separated irradiation trace pattern comprises a dot pattern in which all irradiation traces are arranged separately from each other. According to this method, in the dot pattern, all irradiation traces are arranged separately from each other, thus appropriately reducing the amount of heat input caused by laser irradiation to the isolator.

[0009] (3) Alternatively, the irradiation marks can be arranged at equal intervals in the irradiation mark pattern, based on the above method. According to this method, since the irradiation marks are arranged at equal intervals in the irradiation mark pattern, the cleaning performed by irradiation can be made uniform.

[0010] (4) Alternatively, based on the above method, the separated irradiation mark pattern includes a column pattern having multiple groups of irradiation marks that overlap a portion of adjacent irradiation marks, and the multiple groups of irradiation marks are arranged in a column, separated from each other. According to this method, the cleaning ability can be improved at the locations where the irradiation mark groups overlap a portion of adjacent irradiation marks. Furthermore, since the multiple groups of irradiation marks are arranged in a column, the amount of heat input caused by laser irradiation to the isolator can be reduced.

[0011] (5) Alternatively, based on the above-described method, in the above-described cleaning process, the laser is irradiated onto the first portion of the joint of the first separator comprising the pair of separators included in the single cell in a manner forming the above-described column pattern. Alternatively, the joint is a portion where the first separator is intended to be joined with the second separator comprising the pair of separators. The first portion of the joint is the portion where the force causing the first separator and the second separator to separate due to the pressure of the gas flowing inside the single cell exerts a greater effect than other portions of the joint.

[0012] According to this method, the first portion of the bonding area, where the force causing the pair of separators constituting the single cell to separate due to the pressure of the gas flowing inside the single cell is greater than that of other portions on the surface of the separators, is irradiated with a cleaning laser in a columnar pattern with a higher cleaning force than a dotted pattern. Therefore, the cleaning ability can be maintained at the portion of the separator where a greater peeling force is exerted, thereby maintaining the bonding strength and reducing the warping of the separators.

[0013] (6) Alternatively, the laser can be configured such that, in the cleaning process described above, the direction of the gas pressure is aligned with the parallel direction of the plurality of irradiation mark groups to form a column pattern. According to this configuration, the separation between columns, where the bonding strength is lower than that at the irradiation mark formation sites, is discontinuous in the direction of the gas pressure. Therefore, compared to cases where the direction of the gas pressure and the parallel direction of the irradiation mark groups of the column pattern are, for example, orthogonal, the bonding strength can be improved relative to the gas pressure input.

[0014] (7) Alternatively, based on the above configuration, the isolation member has a refrigerant outlet hole penetrating the isolation member, and in the cleaning process, the laser is irradiated onto the second portion of the joint of the first isolation member in a columnar pattern. Alternatively, the joint is a portion where the first isolation member and the second isolation member, which together with the first isolation member constitute a single cell, are intended to be joined. Alternatively, the second portion of the joint is a portion located around the refrigerant outlet hole.

[0015] According to this method, when the separator is configured as a single cell, the cleaning area around the refrigerant outlet hole, located at the second part of the joint where the force separating the two separators due to gas pressure is greater than that of other parts on the separator surface, can be irradiated with a columnar pattern to form a cleaning force higher than that of a dotted pattern. Therefore, the cleaning ability can be maintained in the cleaning area around the refrigerant outlet hole, thereby maintaining the joint strength and reducing the warping of the separator.

[0016] (8) It can also be configured such that, based on the above method, the isolation member further has a refrigerant inlet hole through the isolation member and a flow path groove extending from the refrigerant inlet hole to the refrigerant outlet hole side, and in the above cleaning process, the laser is irradiated in a column pattern in which the direction of extension of the flow path groove is consistent with the parallel direction of the plurality of irradiation marks.

[0017] When the separator is configured as a single cell, the direction of the flow channel extension is approximately aligned with the direction of the pressure of the gas flowing inside the single cell. According to this method, the separation between rows with lower bonding strength compared to the areas where irradiation marks are formed is discontinuous in the direction of the gas pressure. Therefore, compared to cases where the direction of the gas pressure and the parallel directions of the row-shaped irradiation mark group are, for example, orthogonal, the bonding strength can be improved relative to the input gas pressure.

[0018] (9) According to another aspect of this disclosure, a method for manufacturing a single cell for a fuel cell is provided. This method for manufacturing a single cell for a fuel cell includes: a separator manufacturing step, manufacturing the separator using the method for manufacturing a separator for a fuel cell described above; a separator preparation step, preparing a plurality of the separators manufactured in the separator manufacturing step; an adhesive sheet component setting step, sandwiching a thermoplastic adhesive sheet component between the separators prepared in the separator preparation step; and a hot-pressing step, joining the separators stacked by sandwiching the thermoplastic adhesive sheet component in the adhesive sheet component setting step by hot pressing.

[0019] According to this method, in the separator manufacturing process, it is possible to manufacture a separator that suppresses warping caused by laser irradiation. Furthermore, by proceeding through a separator preparation process, an adhesive sheet component installation process, and a hot-pressing process, a single cell for a fuel cell can be suitably manufactured using a thermoplastic adhesive sheet component.

[0020] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which the same reference numerals denote the same elements. Attached Figure Description

[0021] Figure 1 This is a perspective view showing a simplified structure of a fuel cell using an isolation component manufactured by a manufacturing method for an isolation component for a fuel cell according to the first embodiment of this disclosure.

[0022] Figure 2 This is a top view showing the isolation member manufactured by the method for manufacturing the isolation member in the first embodiment.

[0023] Figure 3 This is a flowchart showing the sequence of manufacturing methods for separators used in fuel cells.

[0024] Figure 4 It is a diagram that schematically represents a dotted pattern.

[0025] Figure 5 It is a diagram that schematically represents a columnar pattern.

[0026] Figure 6 This diagram illustrates the heat-affected zone after laser irradiation treatment.

[0027] Figure 7 This is a diagram illustrating an example of an illumination mark pattern in a comparative method.

[0028] Figure 8 This is a flowchart illustrating the sequence of steps in the manufacturing process of a single cell for a fuel cell. Detailed Implementation

[0029] A. Implementation Method 1:

[0030] A1. Overall structure of a fuel cell:

[0031] Figure 1 This is a perspective view showing a simplified structure of a fuel cell 500 manufactured using a method for manufacturing separators 10 and 20 according to an embodiment of this disclosure. Furthermore, in Figure 1 The surfaces of the separators 10 and 20 are partially simplified in the illustration. The fuel cell 500 is formed by stacking multiple fuel cell individual cells 300 (hereinafter also simply referred to as "individual cells 300") along the stacking direction SD. Hereinafter, the X and Y axes are parallel to the horizontal plane, and the Z axis is parallel to the vertical direction. The +Z direction represents the vertically upward direction, and the -Z direction represents the vertically downward direction. In this embodiment, the stacking direction SD is a direction parallel to the Y axis. In this embodiment, the individual cell 300 is a solid polymer fuel cell. Six manifolds 2 to 7 are formed inside the fuel cell 500.

[0032] Oxidant gas supply manifold 2 supplies air, which serves as the oxidant gas, to each individual cell 300. Cooling medium supply manifold 3 supplies cooling medium to each individual cell 300. Fuel gas exhaust manifold 4 discharges the fuel gas from each individual cell 300 to the outside of the fuel cell 500. Fuel gas supply manifold 5 supplies hydrogen, which serves as the fuel gas, to each individual cell 300. Cooling medium exhaust manifold 6 discharges the cooling medium from each individual cell 300 to the outside of the fuel cell 500. Oxidant gas exhaust manifold 7 discharges the oxidant gas from each individual cell 300 to the outside of the fuel cell 500. All six manifolds 2 to 7 extend parallel to the stacking direction SD.

[0033] Each cell 300 includes a MEGA board 280 and a first isolation member 10 and a second isolation member 20 configured as a pair of isolation members sandwiched in the MEGA board 280 along the stacking direction. Hereinafter, without special distinction between the first isolation member 10 and the second isolation member 20, they will also be referred to as "isolation members 10 and 20".

[0034] MEGA plate 280 includes MEGA (Membrane Electrode and Gas Diffusion Layer Assembly) 200 and support frame 250. MEGA 200 has a structure in which a solid polymer electrolyte membrane, an anode-side catalyst electrode layer, a cathode-side catalyst electrode layer, an anode-side gas diffusion layer, and a cathode-side gas diffusion layer are stacked in the lamination direction SD. A through-hole is provided in the center of the support frame 250 along the thickness direction (Y-axis direction), and MEGA 200 is disposed in this through-hole. Furthermore, the support frame 250 is made of thermoplastic adhesive sheet, and MEGA plate 280 is equivalent to a "thermoplastic adhesive sheet component".

[0035] A2. Structure of the separator:

[0036] Next, the structure of the spacers 10 and 20 will be described. The spacers 10 and 20 are thin plate components with a generally rectangular shape, and have concave and convex shapes formed on both sides in the stacking direction SD. These concave and convex shapes form a gas flow path within the unit for the flow of the reaction gas (fuel gas or oxidant gas). Figure 2 This is a top view showing the first spacer 10 manufactured by the spacer manufacturing method of the first embodiment. Figure 2 The diagram shows the faces of the first spacer 10 that are opposite to the MEGA plate 280. The shape of the second spacer 20 is symmetrical to the shape of the first spacer 10. Therefore, the first spacer 10 will be described representatively.

[0037] like Figure 2 As shown, the first isolation member 10 includes a power generation reaction section 11, a first manifold section 12, a second manifold section 13, an inlet buffer section 14, and an outlet buffer section 15. The power generation reaction section 11 is located approximately at the center in the X direction and is situated between the first manifold section 12 and the second manifold section 13. The power generation reaction section 11 has a plurality of flow path grooves 21 extending linearly in the X direction.

[0038] The first manifold portion 12 is an end edge portion in the -X direction. The first manifold portion 12 has an oxidant gas inlet port 22, a refrigerant inlet port 23, and a fuel gas outlet port 24. These ports 22, 23, and 24 penetrate the separator 10 in the Y direction and are formed sequentially in the -Z direction.

[0039] The second manifold section 13 is located at its end edge in the +X direction. The second manifold section 13 has a fuel gas inlet port 25, a refrigerant outlet port 26, and an oxidant gas outlet port 27. These ports 25, 26, and 27 penetrate the separator 10 in the Y direction and are formed sequentially in the -Z direction. When assembling the fuel cell 500 by stacking multiple single cells 300, the aforementioned six manifolds 2 to 7 are formed by overlapping the ports 22 to 27 in the stacking direction SD.

[0040] The inlet buffer section 14 has multiple embossed sections 28 and is disposed between the first manifold section 12 and the power generation reaction section 11. The outlet buffer section 15 has multiple embossed sections 29 and is disposed between the second manifold section 13 and the power generation reaction section 11.

[0041] The flow channel 21 of the first isolation member 10 functions as a flow path for oxidant gas to flow from the oxidant gas inlet port 22 to the oxidant gas outlet port 27. A similar flow channel (not shown) is formed on the back side of the first isolation member 10, which functions as a refrigerant flow path for refrigerant to flow from the refrigerant inlet port 23 to the refrigerant outlet port 26. The second isolation member 20, like the first isolation member 10, has flow channels formed on both its front and back sides. One flow channel, like the flow channel 21, functions as a refrigerant flow path. The other flow channel functions as a fuel gas flow path for fuel gas to flow from the fuel gas inlet port 25 to the fuel gas outlet port 24.

[0042] A3. Manufacturing method of the separator:

[0043] Next, the manufacturing method of the aforementioned isolation components 10 and 20 will be explained. Figure 3 This is a flowchart illustrating the sequence of manufacturing methods for the fuel cell separators 10 and 20 in the first embodiment. For example... Figure 3 As shown, in the manufacturing method of separators 10 and 20 for fuel cells, firstly, a stamping process is performed in step S101 (hereinafter referred to as "S"), and next, a cleaning process is performed in S102. In the stamping process (S101), as described above, the outer shape of separators 10 and 20 having holes 22 to 27 and flow channel grooves 21 is formed by stamping.

[0044] In the cleaning process (S102), a cleaning laser is irradiated onto the bonding surfaces of the separators 10 and 20 that constitute the single cell 300 and are joined together by overlapping, i.e., the surfaces of each separator 10 and 20 opposite to the MEGA plate 280. Figure 2In the diagram, the cleaning area A, which is the area laser-cleaned in the cleaning process (S102), is shown by a dashed line. Furthermore, the cleaning area A corresponds to the joining area that connects the first spacer 10 and the second spacer 20; the "joining area" and the "cleaning area" are approximately the same location.

[0045] In the cleaning process (S102), at the engagement point of the isolation member (the first isolation member 10 constituting any single cell 300), which is to be engaged with another isolation member (the second isolation member 20 constituting any single cell 300) that is paired with the isolation member and together constitutes the single cell 300, the isolation member is not engaged with other isolation members and is irradiated with laser.

[0046] like Figure 2 As shown, the cleaning portion A includes an outer peripheral cleaning portion A1 near the outer edge of the outer shape of the separator 10, and a hole periphery cleaning portion A2 surrounding the oxidant gas inlet hole 22, the refrigerant inlet hole 23, the refrigerant outlet hole 26, and the oxidant gas outlet hole 27, respectively. The cleaning portion A2 located around the refrigerant outlet hole 26 is substantially the same as the second part of the mating portion.

[0047] In this embodiment, a thermoplastic bonding method is employed to join the spacers 10 and 20 by sandwiching the MEGA plate 280 between the spacers 10 and 20 and heating and stamping the joining area. During this bonding process, if any deposits adhere to the surfaces of the spacers 10 and 20, the bonding quality may be reduced. Therefore, a cleaning process involving irradiating the joining area with a cleaning laser is performed before the bonding process to remove any deposits adhering to the joining area. Furthermore, details of the manufacturing method for the single cell 300, including the process of joining the spacers 10 and 20 using the aforementioned MEGA plate 280 as a thermoplastic adhesive sheet component, will be described later.

[0048] In the cleaning process (S102) of this embodiment, a cleaning laser is irradiated onto the cleaning area A, resulting in multiple irradiation marks 31 (see reference) formed by the cleaning laser. Figure 4 , Figure 5 The separated irradiation trace pattern is formed. The separated irradiation trace pattern has two patterns: a dot pattern DP and a column pattern LP. The formation morphology of the irradiation trace 31 is different for the dot pattern DP and the column pattern LP.

[0049] Figure 4 This is a schematic diagram representing a dot pattern DP. For example... Figure 4 As shown, in the dot pattern DP, all the circular irradiation marks 31 are separated from each other and arranged at equal intervals. A predetermined gap 32 is formed between adjacent irradiation marks 31. Figure 5This is a schematic diagram representing a columnar pattern LP. For example... Figure 5 As shown, in the column pattern LP, there are multiple groups 33 of irradiation marks 31 that partially overlap to form a circular shape, and these multiple groups of irradiation marks 33 are arranged in a column, separated from each other. A predetermined gap 34 is formed between adjacent groups of irradiation marks 33. Furthermore, in Figure 4 , Figure 5 The irradiation mark 31 is schematically illustrated as a perfect circle, but depending on the specifications of the laser beam actually used, it is formed not as a perfect circle but rather as a shape close to an ellipse. Furthermore, the diameter of the irradiation mark 31 is, for example, about 100–150 μm.

[0050] Figure 6 This diagram illustrates the heat-affected zone 41 during laser irradiation treatment, and shows a photograph of the surface of the experimental isolation piece 30 after laser cleaning treatment of the experimental isolation piece 30 which had been coated with black dirt. Figure 6 In the diagram, the irradiation mark 31 is represented by a thin solid line, and the heat-affected zone 41 caused by the laser irradiation is represented by a dashed line. For example... Figure 6 As shown, the black dirt was not removed in the outer part of the heat-affected zone 41, but the heat-affected zone 41 is larger than the irradiation mark 31. The heat-affected zone 41 extends to the outer side of the irradiation mark 31. If it is within the heat-affected zone 41, the dirt can be removed.

[0051] Figure 7 This is a diagram illustrating an example of the irradiation pattern CP in a comparative method. For example... Figure 7 As shown, in the comparison method, an irradiation pattern CP is formed that seamlessly covers the irradiation trace 31. Even if it is not such an irradiation pattern CP, as in the separated irradiation pattern of this embodiment, the deposits can be removed by separating the irradiation traces 31 by a predetermined distance to separate the formation interval of the irradiation traces 31.

[0052] In the aforementioned dotted pattern DP and column pattern LP, gaps 32 and 34 are formed between irradiation marks 31 or between groups of irradiation marks 33. However, these gaps 32 and 34 are set to a degree that does not exceed the heat-affected zone 41, and the adhering material can be removed from the gaps 32 and 34. Furthermore, the diameter and spacing of the irradiation marks 31 can be appropriately changed, but the diameter and spacing are determined in advance through experiments and set to values ​​that satisfy a predetermined threshold for the extent affected by the heat-affected zone 41. In addition, in one direction ( Figure 5 The irradiation marks 31 (shown in the up-down direction) overlap to form a column pattern LP. Compared with the dot pattern DP, the area irradiated by the laser is larger, thus the cleaning ability based on laser irradiation is higher.

[0053] In the cleaning step (S102) of the method for manufacturing the isolation member in the first embodiment, the cleaning part A3 (hereinafter referred to as "high input part A3") in the cleaning part A2 around the refrigerant outlet hole 26, located on the -X direction side and extending in the Z direction, is cleaned. Figure 2 Cleaning is performed by forming a columnar pattern (LP). Figure 2 In this context, the high-input portion A3 is the cleaned area located within the high-input region HA, and is substantially the same as the first part of the joint. For other joints (in... Figure 2 In the process, for example, the part represented as the joint DA is cleaned by forming a dot pattern DP.

[0054] The high-input region HA is the area where, when the separators 10 and 20 are stacked to form a single cell 300, and the single cells 300 are stacked to form a fuel cell 500, the force exerted by the pressure of the reaction gas flowing inside the single cell 300 to peel the two separators 10 and 20 has a greater effect than other parts of the bonding surface of the separators 10 and 20. Therefore, laser cleaning is performed on the high-input region A3, which is the cleaning area located within the high-input region HA, in a columnar pattern LP with higher cleaning capability, so as to improve the bonding strength by more reliably removing the adhering substances.

[0055] Furthermore, in the first embodiment, as Figure 5 As shown, laser light is irradiated in a manner where the direction of gas pressure D1 aligns with the parallel direction D2 of the irradiation trace group 33 of the column pattern LP. The parallel direction D2 is a direction that intersects (or is orthogonal in this embodiment) the direction in which the irradiation trace group 33 extends linearly. By aligning the direction of gas pressure D1 with the parallel direction D2 of the irradiation trace group 33, gaps 34 of the irradiation trace 31 and the column of the irradiation trace group 33 are alternately formed in the direction of gas pressure D1.

[0056] Furthermore, the "direction D1 of gas pressure action" is approximately the same as the "extension direction of the flow channel 21". The irradiation marks 31 are arranged in a seamless row in a direction orthogonal to the direction D1 of gas pressure action, thereby improving the resistance to gas pressure.

[0057] Furthermore, the irradiation mark pattern is adjusted using a known laser welding apparatus. The laser welding apparatus includes a laser emitting unit that moves along a line on the cleaning area A while emitting laser light. The emitting unit actuator moves the laser emitting unit in a manner that forms individual irradiation mark patterns, based on instructions from the control unit.

[0058] In the dot pattern DP, irradiation is turned off after each irradiation in both the scanning and feed directions of the laser emission section. In the column pattern LP, when forming an irradiation mark group 33, the laser emission section is scanned in such a way that the irradiation marks 31 overlap in the scanning direction of the laser emission section. When forming the next column of irradiation mark groups 33, irradiation is temporarily turned off by forming gaps 34 in the feed direction of the laser emission section. Then, the next column of irradiation mark groups 33 is formed in the same manner as described above. Alternatively, the irradiation mark pattern can be adjusted using a laser device equipped with a galvanometer scanner capable of scanning the laser in a two-dimensional direction by changing the reflection direction of the laser.

[0059] A4. Manufacturing method of a single cell:

[0060] Next, refer to Figure 8 The manufacturing method of single cell 300 is explained. Figure 8 This is a flowchart illustrating the sequence of steps in the manufacturing process of a single cell 300. For example... Figure 8 As shown, the manufacturing method of the single cell 300 includes, in the order of the performed steps, a separator manufacturing step (S100), a separator preparation step (S200), an adhesive sheet component setting step (S300), and a heat pressing step (S400).

[0061] In the separator manufacturing process (S100), the first separator 10 and the second separator 20 are manufactured using the aforementioned separator manufacturing method. In the separator preparation process (S200), the first separator 10 and the second separator 20 manufactured in the separator manufacturing process (S100) are prepared. In the adhesive sheet component setting process (S300), a MEGA plate 280 (thermoplastic adhesive sheet component) is sandwiched between the first separator 10 and the second separator 20. In the hot pressing process (S400), the separators 10 and 20, which are stacked with the MEGA plate 280 (thermoplastic adhesive sheet component) sandwiched between them, are joined by hot pressing. Thus, a single cell 300 is manufactured.

[0062] (1) In the manufacturing method of the isolation members 10 and 20 of the first embodiment described above, in the cleaning process (S102), the cleaning area A is irradiated with a cleaning laser in a manner that forms a separated irradiation pattern with irradiation marks 31. Therefore, the irradiation pattern CP (which fills the area without separating the multiple irradiation marks 31) is compared with the irradiation pattern CP (which fills the area without separating the multiple irradiation marks 31). Figure 7 Compared to the case of irradiation (reference), the area affected by heat from the irradiated laser can be reduced.

[0063] That is, it can reduce the amount of heat input caused by laser irradiation of the isolation members 10 and 20, thereby suppressing the warping of the isolation members 10 and 20 caused by the irradiation of the cleaning laser. If warping occurs in the isolation members 10 and 20, poor handling and poor engagement may occur during the handling process of the isolation members 10 and 20, but such problems can be avoided.

[0064] (2) In the manufacturing method of the separators 10 and 20 of the first embodiment described above, when configured as a single cell 300 for a fuel cell, a cleaning laser is irradiated at the high input portion A3, which exerts a greater force on the joint peeling of the separators 10 and 20, to form a column pattern LP with a cleaning force higher than that of the dot pattern DP. Therefore, the deposits in the high input portion A3 can be removed more reliably, thereby improving the joint strength in subsequent bonding processes.

[0065] (3) Furthermore, in the manufacturing method of the isolation members 10 and 20 of the first embodiment described above, the peripheral cleaning area A1, which may have relatively low strength, is irradiated with a cleaning laser in the manner of forming a dot pattern DP. That is, by appropriately using multiple separation irradiation mark patterns with different cleaning capabilities (and even bonding strengths) according to the strength required for each of the multiple cleaning areas, the bonding strength at the required area can be maintained, and the warping of the isolation members 10 and 20 can be appropriately reduced.

[0066] (4) Furthermore, the high input portion A3 is irradiated with laser in a manner where the direction of gas pressure action D1 aligns with the parallel direction D2 of the irradiation mark group 33 of the column pattern LP. Therefore, the gap 34 between the columns, which has a lower bonding strength compared to the portion forming the irradiation mark 31, is discontinuous in the direction of gas pressure action D1. Thus, compared to the case where the direction of gas pressure action D1 is orthogonal to the parallel direction D2 of the irradiation mark group 33 of the column pattern LP, the bonding strength can be improved relative to the gas pressure input.

[0067] B. Other implementation methods:

[0068] (B1) In the first embodiment described above, the irradiation marks 31 in the dot pattern DP are arranged at equal intervals, but they may not be equally spaced as long as the heat-affected zone 41 reaches the desired level. Similarly, the spacing of the irradiation mark groups 33 in the column pattern LP may also not be equally spaced.

[0069] (B2) In the first embodiment described above, the cleaning part A includes the peripheral cleaning part A1 and the hole-around cleaning part A2, but is not limited to this method. The cleaning part A (joint part) can be appropriately changed according to the product specifications of the separators 10 and 20.

[0070] (B3) In the first embodiment described above, the separated irradiation trace pattern has a dot pattern DP and a column pattern LP, but it can be either one or other patterns that allow multiple irradiation traces 31 to be arranged separately.

[0071] (B4) In the first embodiment described above, all clean areas A are irradiated with laser to form a separation irradiation pattern. However, a separation irradiation pattern may also be applied to at least a portion of the clean areas A. For example, it may be configured such that the high-input areas A3 requiring intensity are covered with laser light as a comparison. Figure 7 The irradiation mark 31 shown is irradiated using the irradiation mark pattern CP, while the other cleaned areas A1 and A2 are irradiated using separate irradiation mark patterns. Furthermore, the separate use of the dot pattern DP and the column pattern LP for the cleaned areas can be appropriately modified. For example, it can be configured such that all the cleaned areas A2 around the holes, including the high input area A3, are irradiated using the column pattern LP, while the peripheral cleaned areas A1 are irradiated using the dot pattern DP.

[0072] (B5) In the manufacturing method of the separator in the first embodiment described above, a cleaning process (S102) is performed as a pretreatment for joining the separators 10 and 20 constituting a single cell 300 to the inner surface of the single cell 300, which is the joint surface to be thermoplastically joined using the MEGA plate 280 as a thermoplastic adhesive sheet component. Alternatively, for example, the cleaning process can also be performed as a pretreatment for joining the outer surface of the single cell 300 by welding.

[0073] This disclosure is not limited to the embodiments described above, and can be implemented in various structures without departing from its spirit. For example, technical features in each embodiment corresponding to the technical features in the various methods described in the summary section of the invention can be appropriately replaced or combined. In addition, any technical feature not specified as essential to this specification can be appropriately deleted.

Claims

1. A method for manufacturing a separator for a fuel cell, characterized in that, The method for manufacturing the separator for the fuel cell includes: In the cleaning process, at the predetermined engagement point between the first and second isolation members in the first isolation member, laser irradiation is performed without engaging the first and second isolation members. In the cleaning process, at least a portion of the joint area is irradiated with the laser, so that the multiple irradiation marks formed by the laser become a separated irradiation mark pattern. The separated irradiation trace pattern includes dotted patterns and column patterns in which all irradiation traces are arranged separately from each other. The column pattern has multiple groups of irradiation traces that partially overlap adjacent irradiation traces, and the multiple groups of irradiation traces are arranged separately in columns. In the cleaning process, The laser is irradiated onto a first portion of the joint of the first separator, which constitutes a pair of separators in a single cell, to form the column pattern. The engagement portion is the portion where the first spacer is to be engaged with the second spacer constituting the pair of spacers. The first part of the joint is the part where the force causing the first separator and the second separator to separate from each other due to the pressure of the gas flowing inside the single cell has a greater effect than the other parts of the joint.

2. The manufacturing method according to claim 1, characterized in that, In the separated irradiation trace pattern, the irradiation traces are arranged at equal intervals.

3. The manufacturing method according to claim 1, characterized in that, In the cleaning process, The laser is irradiated to form a column pattern in which the direction of the pressure action of the gas is aligned with the parallel direction of the plurality of irradiation traces.

4. The manufacturing method according to claim 3, characterized in that, The isolation element has a refrigerant outlet hole that extends through the isolation element. In the cleaning process, The laser is irradiated onto the second portion of the engagement area of ​​the first spacer to form the column pattern. The joining portion is the portion where the first separator and the second separator, which together with the first separator constitute a single cell, are joined. The second part of the joint is the portion located around the refrigerant outlet hole.

5. The manufacturing method according to claim 4, characterized in that, The isolation element also has a refrigerant inlet hole that passes through the isolation element and a flow path groove that extends from the refrigerant inlet hole to the refrigerant outlet hole. In the cleaning process, The laser is used to irradiate the area to form a column pattern in which the direction of the flow channel extends is consistent with the parallel direction of the plurality of irradiation traces.

6. A method for manufacturing a single cell for a fuel cell, characterized in that, The method for manufacturing a single cell for a fuel cell includes: The separator manufacturing process involves manufacturing the separator using the method for manufacturing a separator for a fuel cell according to any one of claims 1 to 5; The isolator preparation process prepares a plurality of the isolators to be manufactured through the isolator manufacturing process; The adhesive sheet component placement process involves sandwiching a thermoplastic adhesive sheet component between the spacers prepared in the spacer preparation process; and The heat-pressing process joins the spacers that have been stacked by clamping the thermoplastic adhesive sheet component in the adhesive sheet component setting process.

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