Manufacturing method of electrode and mask

Abstract

To provide a manufacturing method of an electrode capable of suppressing projection in a termination portion of an electrode in a direction of movement of a squeegee.SOLUTION: A manufacturing method of an electrode includes: a disposing step of disposing on a substrate 10 a mask 100 comprising an opening corresponding to a shape of the electrode; and a printing step of filling the opening with an electrode formation material M by moving a squeegee 30 along a surface of the mask 100. The mask 100 comprises a first part 110, a second part 120 and a connection part 130. The first part 110 includes a first specification section 111, and the second part 120 includes a second specification section 121. The connection part 130 includes a thickness decrease section 132, and the thickness decrease section 132 includes a thinnest portion having the same thickness as a thickness of the second part. The thinnest portion is positioned on an extension line of the second specification section 121. In the printing step, the electrode formation material M is pushed into the opening by moving the squeegee 30 from the first part 110 toward the second part 120.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a method for manufacturing an electrode and a mask. [Background technology]

[0002] Japanese Patent Application Laid-Open No. 2003-276353 discloses a metal mask used in thick-film screen printing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-276353 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the method for manufacturing an electrode using a metal mask described in JP 2003-276353 A, an electrode is formed in which the end portion in the direction of squeegee movement of the electrode active material forced into the opening of the metal mask is raised due to surface tension.

[0005] An object of the present disclosure is to provide a method for manufacturing an electrode and a mask capable of suppressing protrusion of the end portion of the electrode in the direction of movement of the squeegee. [Means for solving the problem]

[0006] A method for manufacturing an electrode according to one aspect of the present disclosure includes a placement step of placing a mask for screen printing, the mask having openings corresponding to a shape of the electrode, on a substrate, and a printing step of filling the openings with the electrode-forming material by moving a squeegee along a surface of the mask, wherein the mask used in the placement step has a first portion formed on one side of the opening in a first direction, a second portion formed on the other side of the opening in the first direction, and connecting portions formed on both sides of the opening in a second direction orthogonal to both the first direction and a thickness direction of the mask, connecting the first portion and the second portion; The first portion has a first defining portion that defines an edge on one side of the opening in the first direction, the second portion has a second defining portion that defines an edge on the other side of the opening in the first direction, the connecting portion has a thickness reducing portion having a shape whose thickness gradually decreases toward the second portion, the thickness reducing portion is formed at an end portion on the second portion side in the first direction and has a thinnest portion having the same thickness as the thickness of the second portion, the thinnest portion being located on an extension line of the second defining portion, and in the printing process, the electrode forming material is forced into the opening by moving the squeegee from the first portion toward the second portion.

[0007] A mask according to one aspect of the present disclosure is a mask used in manufacturing an electrode, the mask having an opening corresponding to a shape of the electrode, a first portion formed on one side of the opening in a first direction, a second portion formed on the other side of the opening in the first direction, and a connecting portion formed on both sides of the opening in a second direction perpendicular to both the first direction and a thickness direction of the mask and connecting the first portion and the second portion, the first portion having a first defining portion defining an edge portion on one side of the opening in the first direction, the second portion having a second defining portion defining an edge portion on the other side of the opening in the first direction, the connecting portion having a thickness reducing portion having a shape whose thickness gradually decreases approaching the second portion, the thickness reducing portion being formed at an end portion on the second portion side in the first direction, and having a thinnest portion having the same thickness as a thickness of the second portion, the thinnest portion being located on an extension line of the second defining portion. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a method for manufacturing an electrode and a mask capable of suppressing protrusion of the end portion of the electrode in the moving direction of the squeegee. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a plan view of a mask in accordance with an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] 4A to 4C are cross-sectional views illustrating a printing process. [Figure 4] 6 is a diagram illustrating a relationship between a thickness reducing portion and a squeegee. FIG. [Diagram 5] 11A to 11C are cross-sectional views illustrating a printing process using a mask in a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present disclosure will now be described with reference to the accompanying drawings, in which the same or corresponding components are designated by the same reference numerals.

[0011] Fig. 1 is a plan view of a mask according to an embodiment of the present disclosure. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. The mask 100 is preferably used when manufacturing electrodes for secondary batteries by screen printing. The mask 100 can be used both when manufacturing so-called liquid-based secondary batteries (lithium ion batteries, etc.) having an electrolytic solution, and when manufacturing so-called all-solid-state batteries having a solid electrolyte.

[0012] As shown in Fig. 1, the mask 100 is formed in a ring shape, in this embodiment, a square ring shape. That is, the mask 100 has an opening 100a in the center. The mask 100 may be made of metal. As shown in Figs. 1 and 2, the mask 100 has a first portion 110, a second portion 120, and a connecting portion 130.

[0013] The first portion 110 is formed on one side (the right side in FIG. 1) of the opening 100a in a first direction (the left-right direction in FIG. 1). The first portion 110 has a constant thickness t1 (see FIG. 2). The first portion 110 has a first defining portion 111 that defines an edge on one side of the opening 100a in the first direction.

[0014] The second portion 120 is formed on the other side of the opening 100a in the first direction. The second portion 120 has a constant thickness t2 (see FIG. 2). The second portion 120 has a second defining portion 121 that defines the edge portion on the other side of the opening 100a in the first direction. As shown in FIG. 2, the thickness t2 of the second portion 120 is smaller than the thickness t1 of the first portion 110. It is preferable that the thickness t2 be set to 0.1 mm or more.

[0015] The connecting portion 130 connects the first portion 110 and the second portion 120. The connecting portion 130 is formed on both sides of the opening 100a in a second direction perpendicular to both the first direction and the thickness direction of the mask 100 (the vertical direction in FIG. 2).

[0016] The connecting portion 130 has a thickness reducing portion 132. The thickness reducing portion 132 has a shape in which the thickness of the thickness reducing portion 132 gradually decreases toward the second portion 120. The thickness reducing portion 132 has a thinnest portion 132a formed at an end portion on the second portion 120 side in the first direction. The thinnest portion 132a is located on an extension line of the second defining portion 121. An angle θ2 (see FIG. 4) between the surface of the second portion 120 and the surface of the thickness reducing portion 132 is preferably set to 15 degrees or less. In this case, the difference between the thickness t1 and the thickness t2 is preferably 25% or less of the thickness t1.

[0017] Next, a method for manufacturing an electrode using the mask 100 will be described. This manufacturing method includes an arrangement step and a printing step. In this manufacturing method, in the case of the negative electrode forming material M (graphite, CNT, CMC, SBR), one having a solid content concentration (NV) of 50% to 60% and a viscosity at a shear rate of 1 s during low shear is used, and in the case of the positive electrode forming material M (NCM, CNT, PVDF), one having a solid content concentration (NV) of 55% to 76% and a viscosity at a shear rate of 1 s during low shear is used, and

[0018] In the placement step, the mask 100 is placed on the substrate 10. The substrate 10 is an electrode foil. The substrate 10 is placed on a stage 20. Fig. 2 shows the state after the placement step.

[0019] In the printing process, the electrode-forming material M is filled into the openings 100a by moving the squeegee 30 along the surface of the mask 100. Specifically, as shown by the arrows in Figures 2 and 3, in the printing process, the electrode-forming material M is pushed into the openings 100a by moving the squeegee 30 from the first portion 110 toward the second portion 120. At this time, the angle θ1 (see Figure 4) between the surface of the mask 100 and the bottom surface of the squeegee 30 is set to, for example, 15 degrees. The difference between the thickness t1 and the thickness t2 is set to 25% or less of the thickness t1, thereby improving the followability of the squeegee 30.

[0020] Next, a comparative example of the above embodiment will be described with reference to FIG. 5. FIG. 5 is a cross-sectional view that shows a schematic printing process using a mask in the comparative example. The connecting portion 130 in the mask 101 of the comparative example does not have a thickness-reducing portion 132. That is, the thickness of the mask 101 is formed to be constant over its entire area. When this mask 101 is used, in the printing process, as shown in FIG. 5, the end portion M1 of the electrode in the moving direction of the squeegee 30 is raised by surface tension. For this reason, when this electrode is pressed in a later process, cracks may occur in the electrode.

[0021] In contrast, in the manufacturing method of the electrode in this embodiment, the mask 100 having the thickness reduced portions 132 is used, so that after the printing process, the thickness of the end portion of the electrode in the moving direction of the squeegee 30 (the portion formed between the pair of thickness reduced portions 132) is smaller than the thickness of the other portions of the electrode. Therefore, even if this electrode is pressed in a later process, the occurrence of cracks in the electrode is suppressed.

[0022] It will be appreciated by those skilled in the art that the exemplary embodiments and examples described above are examples of the following aspects.

[0023] [Aspect 1] A method for manufacturing an electrode, comprising the steps of: a step of placing a screen printing mask having openings corresponding to the shape of the electrodes on a substrate; a printing step of filling the openings with an electrode forming material that forms the electrodes by moving a squeegee along a surface of the mask, The mask used in the placement step is a first portion formed on one side of the opening in a first direction; a second portion formed on the other side of the opening in the first direction; a connecting portion that is formed on both sides of the opening in a second direction perpendicular to both the first direction and a thickness direction of the mask, and that connects the first portion and the second portion; the first portion has a first defining portion that defines an edge portion on one side of the opening in the first direction, the second portion has a second defining portion that defines an edge portion on the other side of the opening in the first direction, the connecting portion has a thickness reducing portion having a shape whose thickness gradually decreases toward the second portion, the reduced thickness portion is formed at an end portion on the second portion side in the first direction and has a thinnest portion having the same thickness as the second portion, The thinnest portion is located on an extension line of the second defining portion, In the printing step, the electrode formation material is pushed into the opening by moving the squeegee from the first portion toward the second portion.

[0024] In this electrode manufacturing method, a mask having a reduced thickness is used, so that after the printing process, the thickness of the end portion of the electrode in the direction of squeegee movement is smaller than the thickness of the other portions of the electrode, and therefore, even if the electrode is pressed in a later process, the electrode is prevented from cracking.

[0025] [Aspect 2] A mask for use in the manufacture of an electrode, comprising: An opening corresponding to the shape of the electrode; a first portion formed on one side of the opening in a first direction; a second portion formed on the other side of the opening in the first direction; a connecting portion that is formed on both sides of the opening in a second direction perpendicular to both the first direction and a thickness direction of the mask, and that connects the first portion and the second portion; the first portion has a first defining portion that defines an edge portion on one side of the opening in the first direction, the second portion has a second defining portion that defines an edge portion on the other side of the opening in the first direction, the connecting portion has a thickness reducing portion having a shape whose thickness gradually decreases toward the second portion, the reduced thickness portion is formed at an end portion on the second portion side in the first direction and has a thinnest portion having the same thickness as the second portion, A mask, wherein the thinnest portion is located on an extension line of the second defining portion.

[0026] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. The scope of the present disclosure is indicated by the claims, not by the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0027] 10 substrate, 20 stage, 30 squeegee, 100 mask, 110 first portion, 111 first defining portion, 120 second portion, 121 second defining portion, 130 connecting portion, 132 thickness reducing portion, 132a thinnest portion, M electrode forming material.

Claims

1. A method for manufacturing an electrode, comprising the steps of: a step of placing a mask for screen printing, the mask having openings corresponding to the shape of the electrodes, on a substrate; a printing step of filling the openings with an electrode forming material that forms the electrodes by moving a squeegee along a surface of the mask, The mask used in the placement step is a first portion formed on one side of the opening in a first direction; a second portion formed on the other side of the opening in the first direction; a connecting portion that is formed on both sides of the opening in a second direction perpendicular to both the first direction and a thickness direction of the mask, and that connects the first portion and the second portion; The first portion has a first defining portion that defines an edge portion on one side of the opening in the first direction, the second portion has a second defining portion that defines an edge portion on the other side of the opening in the first direction, the connecting portion has a thickness reducing portion having a shape whose thickness gradually decreases toward the second portion, the reduced thickness portion is formed at an end portion on the second portion side in the first direction and has a thinnest portion having the same thickness as the second portion, The thinnest portion is located on an extension line of the second defining portion, In the printing step, the electrode forming material is pushed into the opening by moving the squeegee from the first portion toward the second portion.

2. A mask for use in the manufacture of an electrode, comprising: An opening corresponding to the shape of the electrode; a first portion formed on one side of the opening in a first direction; a second portion formed on the other side of the opening in the first direction; a connecting portion that is formed on both sides of the opening in a second direction perpendicular to both the first direction and a thickness direction of the mask, and that connects the first portion and the second portion; The first portion has a first defining portion that defines an edge portion on one side of the opening in the first direction, the second portion has a second defining portion that defines an edge portion on the other side of the opening in the first direction, the connecting portion has a thickness reducing portion having a shape whose thickness gradually decreases toward the second portion, the reduced thickness portion is formed at an end portion on the second portion side in the first direction and has a thinnest portion having the same thickness as the second portion, The mask, wherein the thinnest portion is located on an extension line of the second defining portion.

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