Electrode manufacturing method

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

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

Background Art

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

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0007] A mask according to one aspect of the present disclosure is a mask used 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; and connecting portions formed on both sides of the opening in a second direction perpendicular to both the first direction and the thickness direction of the mask, connecting the first portion and the second portion, wherein the first portion has a first defining portion that defines one edge of the opening in the first direction; the second portion has a second defining portion that defines the other edge of the opening in the first direction; the connecting portion has a thickness reduction portion having a shape in which its thickness gradually decreases as it approaches the second portion; the thickness reduction portion is formed at the end 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 being located on the extension of the second defining portion. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide a method for manufacturing electrodes and a mask that can suppress the protrusion of the electrode terminal portion in the direction of movement of the squeegee. [Brief explanation of the drawing]

[0009] [Figure 1] This is a plan view of a mask in one embodiment of the present disclosure. [Figure 2] This is a cross-sectional view taken along line II-II in Figure 1. [Figure 3] This is a cross-sectional view illustrating the printing process in general terms. [Figure 4] This diagram schematically shows the relationship between the thickness reduction area and the squeegee. [Figure 5] This is a cross-sectional view illustrating the printing process using a mask in a comparative example. [Modes for carrying out the invention]

[0010] Embodiments of this disclosure will be described with reference to the drawings. In the drawings referred to below, the same or equivalent components are given the same number.

[0011] Figure 1 is a plan view of a mask in one embodiment of the present disclosure. Figure 2 is a cross-sectional view taken along line II-II in Figure 1. The mask 100 is preferably used when manufacturing electrodes for secondary batteries by screen printing. This mask 100 can be used in both the manufacture of so-called liquid-based secondary batteries (such as lithium-ion batteries) that have an electrolyte, and in the manufacture of so-called all-solid-state batteries that have a solid electrolyte.

[0012] As shown in Figure 1, the mask 100 is formed in an annular, or in this embodiment, a square annular shape. That is, the mask 100 has an opening 100a in its center. The mask 100 may be made of metal. As shown in Figures 1 and 2, the mask 100 has a first part 110, a second part 120, and a connecting part 130.

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

[0014] The second part 120 is formed on the other side of the opening 100a in the first direction. The second part 120 has a constant thickness t2 (see Figure 2). The second part 120 has a second defining portion 121 that defines the other edge of the opening 100a in the first direction. As shown in Figure 2, the thickness t2 of the second part 120 is smaller than the thickness t1 of the first part 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 that is perpendicular to both the first direction and the thickness direction of the mask 100 (the vertical direction in Figure 2).

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

[0017] Next, a method for manufacturing electrodes using mask 100 will be described. This manufacturing method includes a placement step and a printing step. In this manufacturing method, for the negative electrode electrode forming material M (graphite, CNT, CMC, SBR), a solid content concentration (NV) of 50% to 60% and a viscosity of 30,000 mPa·s to 70,000 mPa·s at a shear rate of 1 s during low shear are used. For the positive electrode electrode forming material M (NCM, CNT, PVDF), a solid content concentration (NV) of 55% to 76% and a viscosity of 30,000 mPa·s to 70,000 mPa·s at a shear rate of 1 s during low shear are used.

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

[0019] In the printing process, the electrode forming material M is filled into the opening 100a by moving the squeegee 30 along the surface of the mask 100. Specifically, as indicated by the arrows in FIGS. 2 and 3, in the printing process, the electrode forming material M is pushed into the opening 100a by moving the squeegee 30 from the first portion 110 toward the second portion 120. At this time, the angle θ1 (see FIG. 4) formed between the surface of the mask 100 and the bottom surface of the squeegee 30 is set to, for example, 15 degrees. By setting the difference between the thickness t1 and the thickness t2 to be 25% or less of the thickness t1, the followability of the squeegee 30 is enhanced.

[0020] Next, referring to FIG. 5, a comparative example with respect to the above-described embodiment will be described. FIG. 5 is a cross-sectional view schematically showing a printing process using the mask in the comparative example. The connecting portion 130 of the mask 101 in the comparative example does not have a thickness reduction portion 132. That is, the thickness of the mask 101 is formed to be constant over the entire area thereof. 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 bulges due to surface tension. Therefore, when this electrode is pressed in a subsequent process, cracks may occur in the electrode.

[0021] On the other hand, in the method for manufacturing an electrode according to the present embodiment, since the mask 100 having the thickness reduction portion 132 is used, after the printing process, the thickness of the end portion of the electrode (the portion formed between the pair of thickness reduction portions 132) in the moving direction of the squeegee 30 becomes smaller than the thickness of the other portions of the electrode. Therefore, even when this electrode is pressed in a subsequent process, the occurrence of cracks in the electrode is suppressed.

[0022] Those skilled in the art will understand that the above-described exemplary embodiments and examples are specific examples of the following aspects.

[0023] [Aspect 1] A method for manufacturing an electrode, An arrangement step of arranging, on a substrate, a mask for screen printing, the mask having an opening corresponding to the shape of the electrode, The process includes a printing step of filling the opening with an electrode-forming material that forms the electrode by moving a squeegee along the surface of the mask, The mask used in the aforementioned placement step is A first portion formed on one side of the opening in the first direction, A second portion formed on the other side of the opening in the first direction, It has connecting portions formed on both sides of the opening in a second direction perpendicular to both the first direction and the thickness direction of the mask, which connect the first part and the second part, The first part has a first defining portion that defines one edge of the opening in the first direction, The second part has a second defining part that defines the other edge of the opening in the first direction, The connecting portion has a thickness reduction portion which has a shape in which its thickness gradually decreases as it approaches the second portion. The aforementioned thickness reduction portion is formed at the end 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 the extension of the second defined portion, A method for manufacturing an electrode, wherein in the printing step, the electrode forming material is pressed into the opening by moving the squeegee from the first part to the second part.

[0024] In this electrode manufacturing method, a mask with a thickness reduction section is used. Therefore, after the printing process, the thickness of the electrode's end portion in the direction of squeegee movement is smaller than the thickness of other parts of the electrode. Consequently, even if the electrode is pressed in a later process, cracking of the electrode is suppressed.

[0025] [Aspect 2] A mask used in the manufacture of electrodes, An opening corresponding to the shape of the electrode, A first portion formed on one side of the opening in the first direction, A second portion formed on the other side of the opening in the first direction, It has connecting portions formed on both sides of the opening in a second direction perpendicular to both the first direction and the thickness direction of the mask, which connect the first part and the second part, The first part has a first defining portion that defines one edge of the opening in the first direction, The second part has a second defining part that defines the other edge of the opening in the first direction, The connecting portion has a thickness reduction portion which has a shape in which its thickness gradually decreases as it approaches the second portion. The aforementioned thickness reduction portion is formed at the end on the second portion side in the first direction, and has a thinnest portion having the same thickness as the second portion. The thinnest part of the mask is located on the extension of the second defined part.

[0026] It should be noted that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of this disclosure is defined by the claims rather than the description of the embodiments above, and includes all modifications within the meaning and scope equivalent to the claims. [Explanation of symbols]

[0027] 10 Substrate, 20 Stage, 30 Squeegee, 100 Mask, 110 First part, 111 First normalized part, 120 Second part, 121 Second normalized part, 130 Connecting part, 132 Thickness reduction part, 132a Thinnest part, M Electrode forming material.

Claims

1. A method for manufacturing electrodes, A placement step of placing a mask for screen printing, which has openings corresponding to the shape of the electrodes, on a substrate, The process includes a printing step of filling the opening with an electrode-forming material that forms the electrode by moving a squeegee along the surface of the mask, The mask used in the aforementioned placement step is A first portion formed on one side of the opening in the first direction, A second portion formed on the other side of the opening in the first direction, It has connecting portions formed on both sides of the opening in a second direction perpendicular to both the first direction and the thickness direction of the mask, which connect the first part and the second part, The first part has a first defining portion that defines one edge of the opening in the first direction, The second part has a second defining part that defines the other edge of the opening in the first direction, The connecting portion has a thickness reduction portion which has a shape in which its thickness gradually decreases as it approaches the second portion. The aforementioned thickness reduction portion is formed at the end 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 the extension of the second defined portion, The thickness reduction portion is composed of a surface opposite to the surface facing the substrate, and includes an inclined surface at the thinnest portion that connects to the surface of the second portion. A method for manufacturing an electrode, wherein in the printing step, the squeegee is moved from the surface of the first part toward the surface of the second part, along the inclined surface of the thickness reduction portion, to the surface of the second part, thereby pressing the electrode forming material into the opening.

2. The angle between the surface of the second part and the inclined surface is 15 degrees or less. The method for manufacturing an electrode according to claim 1, wherein the difference between the thickness of the first part and the thickness of the second part is 25% or less of the thickness of the first part.

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