Method for manufacturing flow guides for electrochemical reactors

Abstract

To provide a method for manufacturing printed fluidic circuits enabling to reduce the width of a tooth / channel step.SOLUTION: The present invention relates to a method for manufacturing at least one flow-guide 1 for an electrochemical reactor. The method includes the steps of: a) providing a substrate 10; b) providing a first mesh screen comprising openings configured to form a first pattern 21 of ribs of a first flow-guide 1; and c) providing a second mesh screen comprising openings configured to form a second pattern of ribs 221 of the first flow-guide 1. The present invention uses a mesh screen printing technique to produce fluidic circuits with a large channel depth and with an aspect ratio equal to or greater than 1.SELECTED DRAWING: Figure 11

Claims

1. A method for manufacturing at least one flow guide (1, 1') for an electrochemical reactor, a. The step of providing a substrate (10), b. Providing a first mesh screen (11) having openings (111) configured to form a first pattern (21) of the ribs (211) of the first flow guide (1), c. Providing a second mesh screen (12) having openings (121) configured to form a second pattern (22) of the ribs (221) of the first flow guide (1), The second pattern (22) provides a second mesh screen (12) such that when the second mesh screen (12) is superimposed on the first mesh screen (11), each of the openings (121) of the second mesh screen (12) is simultaneously positioned to coincide with the openings (111) of the first mesh screen (11), and the openings (121) of the second mesh screen (12) have a smaller surface area compared to the openings (111) of the first mesh screen (11); and then, On the first surface (101) of the substrate (10), d. The step of printing a first layer (31) of the first conductive ink by screen printing using the first mesh screen (11), e. The step of forming the first pattern (21) of the rib (211) by drying the first layer (31), f. A step of positioning the second mesh screen (12) so that it partially rests on each of the ribs (211) of the first pattern (21), wherein each opening (121) of the second mesh screen (12) is positioned to coincide with the ribs (211) of the first pattern (21); and then, g. The steps of printing a second layer (32) of the second conductive ink by screen printing using the previously positioned second mesh screen (12), drying the second layer (32), and then superimposing the second pattern (22) on the first pattern (21); Includes, h. A step of positioning the first mesh screen (11) so that it partially rests on each of the ribs (221) of the second pattern (22), wherein the opening (111) of the first mesh screen (11) is partially occupied by at least one portion of the ribs (221) of the second pattern (22), i. The steps of printing a third layer (33) of a third conductive ink by screen printing using the previously positioned first mesh screen (11), drying the third layer (33), and then enlarging at least one of the ribs (221) of the second pattern (22) to obtain an enlarged rib (222); Methods that further include the above.

2. The method according to claim 1, wherein the opening (121) of the second mesh screen (12) is configured and positioned so that when the second mesh screen (12) is positioned, it can be centered on the rib (211) of the first pattern (21).

3. j. The step of positioning the second mesh screen (12) so that it partially rests on each of the enlarged ribs (222), and then k. The steps of printing another layer of conductive ink by screen printing using the previously positioned second mesh screen (12), drying it, and then superimposing the second pattern onto the enlarged ribs (222), and then l. A step of positioning the first mesh screen (11) so as to partially rest on each of the ribs of the previously printed second pattern, wherein the opening (111) of the first mesh screen (11) is partially occupied by at least one portion of the ribs of the second pattern that overlaps with the enlarged rib (222), m. The steps of printing another layer of conductive ink by screen printing using the previously positioned first mesh screen (11), drying it, and then expanding the ribs of the second pattern to obtain newly expanded ribs. The method according to claim 1 or 2, further comprising the sequence at least once.

4. The method according to any one of claims 1 to 3, wherein the provided substrate (10) is a conductive plate (130), and steps d to g of the method, and optionally steps d to i, are repeated on a second surface (102) of the substrate (10).

5. The provided substrate (10) is a conductive plate (130), and steps d to g of the method, optionally steps d to i, are repeated on a second surface (102) of the substrate (10) to manufacture a second flow guide (1'). The method according to claim 3, wherein steps j to m are repeated on the second surface (102) of the substrate (10) to manufacture the second flow guide (1').

6. The method according to any one of claims 1 to 5, wherein the difference in surface area between the opening (121) of the second mesh screen (12) and the opening (111) of the first mesh screen (11) is such that when the second mesh screen (12) is placed on the first pattern (21), the second mesh screen (12) rests on 5 to 20% of the upper surface of the ribs (211) of the first pattern (21).

7. The method according to any one of claims 1 to 6, wherein the difference in surface area between the opening (121) of the second mesh screen (12) and the opening (111) of the first mesh screen (11) includes a difference in width greater than 40 μm between the opening (121) of the second mesh screen (12) and the opening (111) of the first mesh screen (11).

8. The method according to any one of claims 1 to 7, wherein each mesh screen (11, 12) comprises meshing (112, 122) and emulsion (113, 123), and the second mesh screen (12) is positioned on the first pattern (21) such that a portion of the emulsion (123) of the second mesh screen (12) rests partially on each of the ribs (211) of the first pattern (21).

9. The method according to any one of claims 1 to 8, wherein each mesh screen (11, 12) comprises meshing (112, 122) and emulsion (113, 123), and the first mesh screen (11) is positioned on the second pattern (22) such that a portion of the meshing (112) of the first mesh screen (11) rests on each of the ribs (221) of the second pattern (22).

10. Each mesh screen (11, 12) comprises meshing (112, 122) and emulsion (113, 123). - The thickness of the emulsion (113, 123) is 100 to 200 μm, and / or The method according to any one of claims 1 to 9, wherein the thickness of the meshing (112, 122) is 50 to 150 μm.

11. The method according to any one of claims 1 to 10, wherein the first mesh screen (11) comprises meshing (112) and emulsion (113), the pattern of the emulsion (113) of the first mesh screen (11) is negative of the first pattern (21), defining a flow path (2) of the first flow guide (1) between the ribs (211) of the first pattern (21), the width of the flow path (2) being defined by the opening (111) of the first mesh screen (11) and being 1 to 4 times the width of the ribs (211) of the first pattern (21).

12. Each layer (31, 32, 33) of conductive ink is printed by screen printing while applying shear stress to the layer, and the viscosity of the ink being printed is 0.1 s. －１ The shear rate is 70 to 500 Pa·s, and the viscosity of the ink to be printed is 100 s. －１ The method according to any one of claims 1 to 11, wherein the shear rate is 2.5 to 7 Pa.s.

13. The method according to any one of claims 1 to 12, wherein the provided substrate (10) comprises at least one of the gas diffusion layer (120) of the electrochemical reactor, the electrode layer (110) of the electrochemical reactor, and the conductive plate (130).

14. A method for manufacturing a bipolar plate (3) for an electrochemical reactor, more specifically for a proton exchange membrane fuel cell, - A step of manufacturing at least three flow guides (1, 1', 1") on at least two substrates (10, 10', 10") by a manufacturing method according to any one of claims 1 to 13, - A step of assembling the at least two substrates (10, 10', 10") together to manufacture at least one assembly, wherein the assembly has one of the at least three flow guides (1') between two of the at least two substrates (10, 10', 10"), and the other two of the at least three flow guides (1, 1") on both sides of the at least two substrates (10, 10', 10"), and Methods that include...

15. A flow guide (1, 1') for an electrochemical reactor comprising a substrate (10), wherein a rib defining a flow path extends over at least one of two surfaces of the substrate (10), The ribs are made from at least one conductive material different from the base material of the substrate (10), and have a thickness that is strictly greater than the width of the flow path. Each rib extends from at least one of the two surfaces of the substrate (10) by at least one first portion made from a first conductive material different from the substrate (10), At least one second portion, made from a second conductive material different from the substrate, extends from the first portion and has a width narrower than the width of the first portion of each rib. The third portion extends from at least one side of the second portion, A flow guide (1, 1') for an electrochemical reactor, wherein the third portion is made from a third conductive material, the third conductive material being different from the second conductive material.

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