Electrode tab welding quality inspection device and method

Abstract

The present invention provides an electrode tab welding quality inspection device (1) comprising: an image acquisition unit (10) for acquiring an image (G) in which one or more welding parts (W) of an electrode (5) and an electrode tab (6) are captured; a pixel number calculation unit (24) for calculating a first number of one or more effective pixels having a brightness value or a color value satisfying a predetermined condition in the image (G); and a welding quality determination unit (26) for determining welding quality of the one or more welding parts (W) on the basis of the first number. Each of the welding parts (W) can include one or more welding points (P) at which the electrode (5) and the electrode tab (6) are actually welded. The brightness value or the color value of one or more pixels corresponding to one or more welding points (P) can satisfy the predetermined condition.

Description

Device and method for inspecting welding quality of electrode tabs

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0131777 filed September 27, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0002] The present invention relates to an apparatus and method for inspecting the welding quality of electrode tabs, and more specifically, to an apparatus and method for inspecting the welding quality of electrode tabs that can perform a simple, rapid, and accurate non-destructive, automatic, and 100% inspection, thereby reducing electrode manufacturing costs.

[0003] The demand for secondary batteries is rapidly increasing due to the growing demand for mobile devices and electric vehicles. In particular, lithium-ion batteries, which possess high energy density and voltage, have been commercialized and are widely used.

[0004] Generally, a secondary battery is completed by manufacturing an electrode by applying an electrode mixture, comprising an electrode active material, a conductive agent, a binder, etc., onto an electrode current collector and drying it, stacking the manufactured electrode together with a separator, and then embedding and sealing it in a battery case along with an electrolyte.

[0005] The electrode is manufactured by welding an electrode tab to an uncoated portion of an electrode sheet where the electrode active material is not coated, or by forming an electrode tab using a notching device, and then cutting the electrode sheet to a predetermined length.

[0006] Conventionally, to inspect the welding quality of electrode tabs, workers or others measured tensile strength by pulling the tabs with a gripper. However, since this conventional inspection method is a destructive method, 100% inspection is impossible, and the requirement for manual labor increased electrode manufacturing costs. Therefore, there is a need for a method that can non-destructively and automatically inspect the welding quality of electrode tabs for 100%. A prior art document related to this is Korean Published Patent No. 10-2023-0059596.

[0007] The present invention was devised to solve the aforementioned problems and aims to provide an apparatus and method for inspecting the welding quality of electrode tabs, which can perform a simple, rapid, and accurate non-destructive, automatic, and 100% inspection of the welding quality of electrode tabs.

[0008] The present invention was devised to solve the aforementioned problems and aims to provide a welding quality inspection device and method for electrode tabs that reduce electrode manufacturing costs.

[0009] The present invention was devised to solve the aforementioned problems and aims to provide a welding quality inspection device and method for an electrode tab capable of ensuring welding quality of a specific welding area.

[0010] The present invention was devised to solve the aforementioned problems and aims to provide an electrode tab welding quality inspection device and method that flexibly determine the overall welding quality of the electrode and the electrode tab.

[0011] The technical problems of the present invention are not limited to the purposes mentioned above, and other unmentioned purposes and advantages of the present invention may be understood from the following description and will be more clearly understood by the embodiments of the present invention. Furthermore, it will be readily apparent that the purposes and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0012] To solve the above-mentioned problem, the present invention provides a welding quality inspection device (1) for an electrode tab comprising an image acquisition unit (10), a pixel count calculation unit (24), and a welding quality judgment unit (26).

[0013] The above image acquisition unit (10) can acquire an image (G) of one or more welded parts (W) of the electrode (5) and the electrode tab (6).

[0014] The pixel count calculation unit (24) can obtain a first number of one or more effective pixels in the image (G) in which the brightness value or color value satisfies a predetermined condition.

[0015] The welding quality judgment unit (26) above can determine the welding quality of one or more welding parts (W) based on the first number.

[0016] Each of the above-mentioned welded portions (W) may include one or more weld points (P) where the electrode (5) and the electrode tab (6) are actually welded.

[0017] In the above image (G), the brightness value or color value of one or more pixels corresponding to one or more weld points (P) may satisfy the above predetermined condition.

[0018] In one embodiment, each of the welded portions (W) may include a plurality of unit welded portions (U).

[0019] The above plurality of unit welded parts (U) can be positioned spaced apart from each other.

[0020] Each of the above plurality of unit welded parts (U) may include a portion of the above one or more weld points (P).

[0021] In one embodiment, the welding may be ultrasonic welding.

[0022] The above one or more welding points (P) may be points where the electrode (5) and the electrode tab (6) are pressure-fused by the welding horn (84).

[0023] In one embodiment, the electrode (5) to which the electrode tab (6) is welded may be a single sheet-type electrode.

[0024] In one embodiment, the welding quality inspection device (1) of the electrode tab may further include a light irradiation unit (30).

[0025] The light irradiation unit (30) can irradiate light onto one or more welded parts (W).

[0026] The light irradiation unit (30) above may include coaxial illumination (32).

[0027] The above coaxial illumination (32) can irradiate light in the same direction as the image acquisition unit (10) looks at the one or more welded parts (W).

[0028] While the light irradiation unit (30) irradiates light onto one or more welded parts (W), the image acquisition unit (10) can acquire the image (G).

[0029] In one embodiment, the welding quality inspection device (1) of the electrode tab may further include an area setting unit (22).

[0030] The above region setting unit (22) can set one or more regions of interest (R).

[0031] One or more regions of interest (R) may have a smaller area than the image (G) in the image (G).

[0032] The above one or more regions of interest (R) may each include the above one or more welded parts (W).

[0033] The pixel count calculation unit (24) can obtain the first number from one or more regions of interest (R).

[0034] In one embodiment, the pixel count calculation unit (24) can obtain a second number of one or more valid pixels in each of the regions of interest (R).

[0035] The welding quality judgment unit (26) can determine the welding quality of each welding part (W) based on the second number in each of the areas of interest (R).

[0036] In one embodiment, the welding quality judgment unit (26) can determine that the overall welding quality of the electrode (5) and the electrode tab (6) is defective if the welding quality of the first welding part (W1) among the plurality of welding parts (W) is determined to be defective.

[0037] In one embodiment, the electrode tab (6) may include an overlapping portion (62) and a protrusion (64).

[0038] The above-mentioned overlapping portion (62) may come into contact with or face the electrode (5).

[0039] The above protrusion (64) can be placed on one side of the above overlap portion (62).

[0040] The above protrusion (64) may protrude to one side above the electrode (5).

[0041] The first welded portion (W1) above may be the welded portion (W) located closest to the protrusion (64) among the plurality of welded portions (W).

[0042] In one embodiment, the welding quality judgment unit (26) can determine that the overall welding quality of the electrode (5) and electrode tab (6) is defective if the welding quality of m (m is a natural number smaller than n) or more of the welding parts (W) among n (n is a natural number greater than or equal to 2) of the welding parts (W) is determined to be defective.

[0043] In addition, to solve the above-mentioned problem, the present invention provides a welding quality inspection method (S90) of an electrode tab comprising an image acquisition process (S92), a pixel count calculation process (S96), and a welding quality judgment process (S98).

[0044] In the above image acquisition process (S92), the image acquisition unit (10) can acquire the image (G) that captures one or more welded parts (W) of the electrode (5) and the electrode tab (6).

[0045] In the above pixel count calculation process (S96), the pixel count calculation unit (24) can obtain the first number of one or more valid pixels in the image (G) in which the brightness value or color value satisfies the above predetermined condition.

[0046] In the above welding quality judgment process (S98), the welding quality judgment unit (26) can determine the welding quality of one or more welding parts (W) based on the first number.

[0047] Each of the above-mentioned welded portions (W) may include one or more weld points (P) where the electrode (5) and the electrode tab (6) are actually welded.

[0048] In the above image (G), the brightness value or color value of one or more pixels corresponding to one or more weld points (P) may satisfy the above predetermined condition.

[0049] In one embodiment, each of the welded portions (W) may include a plurality of unit welded portions (U).

[0050] The above plurality of unit welded parts (U) can be positioned spaced apart from each other.

[0051] Each of the above plurality of unit welded parts (U) may include a portion of the above one or more weld points (P).

[0052] In one embodiment, the welding may be ultrasonic welding.

[0053] The above one or more welding points (P) may be points where the electrode (5) and the electrode tab (6) are pressure-fused by the welding horn (84).

[0054] In one embodiment, the electrode (5) to which the electrode tab (6) is welded may be a single sheet-type electrode.

[0055] In one embodiment, in the image acquisition process (S92), the image acquisition unit (10) can acquire the image (G) while the coaxial illumination (32) of the light irradiation unit (30) irradiates light onto one or more welded parts (W) in the same direction as the image acquisition unit (10) looks at the one or more welded parts (W).

[0056] In one embodiment, the welding quality inspection method (S90) of the electrode tab may further include a region setting process (S94).

[0057] In the above area setting process (S94), the area setting unit (22) can set one or more areas of interest (R).

[0058] Each of the above regions of interest (R) may have a smaller area than the image (G) in the above image (G).

[0059] The above one or more regions of interest (R) may each include the above one or more welded parts (W).

[0060] In the above pixel count calculation process (S96), the pixel count calculation unit (24) can obtain the first number from one or more regions of interest (R).

[0061] In one embodiment, in the pixel count calculation process (S96), the pixel count calculation unit (24) can obtain a second number of one or more valid pixels in each of the regions of interest (R).

[0062] In the above welding quality judgment process (S98), the welding quality judgment unit (26) can determine the welding quality of each welding part (W) based on the second number in each of the areas of interest (R).

[0063] In one embodiment, in the welding quality judgment process (S98), the welding quality judgment unit (26) can determine that the overall welding quality of the electrode (5) and the electrode tab (6) is defective if the welding quality of the first welding part (W1) among the plurality of welding parts (W) is determined to be defective.

[0064] In one embodiment, the electrode tab (6) may include an overlapping portion (62) and a protrusion (64).

[0065] The above-mentioned overlapping portion (62) may come into contact with or face the electrode (5).

[0066] The above protrusion (64) can be positioned on one side of the above overlap portion (62).

[0067] The above protrusion (64) may protrude to one side above the electrode (5).

[0068] The first welded portion (W1) above may be the welded portion (W) located closest to the protrusion (64) among the plurality of welded portions (W).

[0069] In one embodiment, in the welding quality judgment process (S98), the welding quality judgment unit (26) can determine that the overall welding quality of the electrode (5) and electrode tab (6) is defective if the welding quality of m (m is a natural number smaller than n) or more welding parts (W) among n (n is a natural number greater than or equal to 2) welding parts (W) is determined to be defective.

[0070] According to embodiments of the present invention, a welding quality inspection device (1) for an electrode tab may include: an image acquisition unit (10) for acquiring an image (G) of one or more welding parts (W) of an electrode (5) and an electrode tab (6); a pixel count calculation unit (24) for obtaining a first number of one or more effective pixels in which a brightness value or color value satisfies a predetermined condition in the image (G); and a welding quality judgment unit (26) for determining the welding quality of one or more welding parts (W) based on the first number. Each of the welding parts (W) may include one or more welding points (P) where the electrode (5) and the electrode tab (6) are actually welded. The brightness value or color value of one or more pixels corresponding to one or more welding points (P) in the image (G) may satisfy the predetermined condition.

[0071] Accordingly, since the welding quality is determined by the number of pixels corresponding to one or more actual weld points (P), the welding quality of the electrode tab (6) can be inspected non-destructively and automatically in a simple, rapid, and accurate manner.

[0072] In addition, since it can replace conventional welding quality inspections (self inspection, sampling inspection, destructive inspection), the manufacturing cost of the electrode (5) can be reduced. Here, the self inspection and / or sampling inspection may be a destructive inspection in which a worker or others pull the electrode tab (6) or the electrode (5) to measure the tensile strength of one or more welded parts (W).

[0073] According to embodiments of the present invention, each of the welded portions (W) may include a plurality of unit welded portions (U) that are spaced apart from each other and each include a portion of one or more welded points (P).

[0074] Accordingly, even if each welded part (W) includes multiple unit welded parts (U), the welding quality can be determined by the number of pixels corresponding to multiple weld points (P) without considering the characteristics of the multiple unit welded parts (U). Accordingly, the welding quality of the electrode tab (6) can be inspected simply, quickly, and accurately.

[0075] According to embodiments of the present invention, the welding may be ultrasonic welding. The one or more welding points (P) may be points where the electrode (5) and the electrode tab (6) are pressure-fused by a welding horn (84).

[0076] Accordingly, the welding quality of the electrode tab (6) can be inspected more accurately. Specifically, since the electrode (5) and the electrode tab (6) are pressure-fused by the welding horn (84) of the ultrasonic welder (80) at one or more welding points (P), the surface of the electrode (5) or the electrode tab (6) may be sloped or the density may change at one or more welding points (P). Accordingly, the brightness value or color value of the pixel corresponding to one or more welding points (P) may be clearly different from the brightness value or color value of other pixels. Therefore, the number of pixels corresponding to one or more welding points (P) can be accurately determined, so the welding quality can be inspected accurately.

[0077] According to embodiments of the present invention, the electrode (5) to which the electrode tab (6) is welded may be a single sheet-type electrode.

[0078] Accordingly, the welding quality of the electrode tab (6) can be inspected more accurately. Specifically, for example, a single sheet-type electrode (5) has a small thickness, so it can easily deform together with the electrode tab (6) during welding, causing it to tilt or change density. Therefore, the brightness value or color value of one or more pixels corresponding to one or more welding points (P) can be clearly different from the brightness value or color value of other pixels. Accordingly, the number of one or more pixels corresponding to one or more welding points (P) can be accurately determined, so the welding quality can be inspected accurately.

[0079] According to embodiments of the present invention, the welding quality inspection device (1) of the electrode tab may further include a light irradiation unit (30) that irradiates light onto one or more welding parts (W). While the light irradiation unit (30) is irradiating light onto one or more welding parts (W), the image acquisition unit (10) may acquire the image (G).

[0080] Accordingly, the difference in brightness or color value between one or more pixels corresponding to one or more welding points (P) and other pixels may increase. Accordingly, the welding quality of the electrode tab (6) can be accurately inspected.

[0081] According to embodiments of the present invention, the light irradiation unit (30) may include a coaxial light (32) that irradiates light in the same direction as the image acquisition unit (10) looks at the one or more welded parts (W).

[0082] Accordingly, since the accurate surface brightness of each weld area (W) from which shadows have been removed can be obtained, the number of pixels corresponding to one or more weld points (P) can be accurately determined. Therefore, the welding quality can be accurately inspected.

[0083] According to embodiments of the present invention, the welding quality inspection device (1) of the electrode tab may further include a region setting unit (22) for setting one or more regions of interest (R) that are smaller in area than the image (G) and each include one or more welding parts (W). The pixel count calculation unit (24) can obtain the first count from the one or more regions of interest (R).

[0084] Accordingly, the search range of valid pixels is reduced, thereby reducing the false positive rate of valid pixels. As a result, the welding quality of the electrode tab (6) can be accurately inspected.

[0085] According to embodiments of the present invention, the pixel count calculation unit (24) can obtain a second number of one or more valid pixels in each of the regions of interest (R). The welding quality judgment unit (26) can determine the welding quality of each welding part (W) based on the second number in each of the regions of interest (R).

[0086] Accordingly, the welding quality of each welding area (W) of the electrode (5) and electrode tab (6) can be inspected non-destructively and automatically in a simple, rapid, and accurate manner.

[0087] According to embodiments of the present invention, the welding quality judgment unit (26) can determine that the overall welding quality of the electrode (5) and the electrode tab (6) is defective if the welding quality of the first welding part (W1) among the plurality of welding parts (W) is determined to be defective.

[0088] Accordingly, the welding quality of the first welded part (W1) can be ensured.

[0089] According to embodiments of the present invention, the electrode tab (6) may include an overlapping portion (62) that contacts or faces the electrode (5) and a protrusion (64) disposed on one side of the overlapping portion (62) and protruding toward the one side more than the electrode (5). The first welded portion (W1) may be the welded portion (W) located closest to the protrusion (64) among the plurality of welded portions (W).

[0090] Accordingly, the welding quality of the first welding portion (W1) closest to the protrusion (64) can be ensured. Accordingly, even if an external force is applied to the protrusion (64) of the electrode tab (6), the state in which the electrode tab (6) is welded to the electrode (5) can be stably maintained.

[0091] According to embodiments of the present invention, the welding quality judgment unit (26) can determine that the overall welding quality of the electrode (5) and electrode tab (6) is defective if the welding quality of m (m is a natural number smaller than n) or more of the welding parts (W) among n (n is a natural number greater than or equal to 2) of the welding parts (W) is determined to be defective.

[0092] Accordingly, the overall welding quality of the electrode (5) and the electrode tab (6) can be flexibly determined.

[0093] According to embodiments of the present invention, the m may be an integer part of the n divided by 2.

[0094] Accordingly, the overall welding quality of the electrode (5) and the electrode tab (6) can be flexibly determined.

[0095] According to embodiments of the present invention, a welding quality inspection method (S90) for an electrode tab may include: an image acquisition process (S92) in which the image acquisition unit (10) acquires an image (G) in which one or more welding parts (W) of the electrode (5) and the electrode tab (6) are photographed; a pixel count calculation process (S96) in which the pixel count calculation unit (24) obtains a first number of one or more valid pixels in the image (G) in which a brightness value or a color value satisfies a predetermined condition; and a welding quality judgment process (S98) in which the welding quality judgment unit (26) determines the welding quality of one or more welding parts (W) based on the first number. Each of the welding parts (W) may include one or more welding points (P) where the electrode (5) and the electrode tab (6) are actually welded. In the above image (G), the brightness value or color value of one or more pixels corresponding to one or more weld points (P) may satisfy the above predetermined condition.

[0096] Accordingly, since the welding quality is determined by the number of pixels corresponding to one or more actual weld points (P), the welding quality of the electrode tab (6) can be inspected non-destructively and automatically in a simple, rapid, and accurate manner.

[0097] In addition, since it can replace conventional welding quality inspection (self inspection, sampling inspection, destructive inspection), the manufacturing cost of the electrode (5) can be reduced.

[0098] According to embodiments of the present invention, each of the above-mentioned welded portions (W) may include a plurality of unit welded portions (U) that are spaced apart from each other and each include a portion of one or more of the above-mentioned weld points (P).

[0099] Accordingly, the welding quality of the electrode tab (6) can be inspected simply, quickly, and accurately.

[0100] According to embodiments of the present invention, the welding may be ultrasonic welding. The one or more welding points (P) may be points where the electrode (5) and the electrode tab (6) are pressure-fused by a welding horn (84).

[0101] Accordingly, the welding quality of the electrode tab (6) can be inspected more accurately.

[0102] According to embodiments of the present invention, the electrode (5) to which the electrode tab (6) is welded may be a single sheet-type electrode.

[0103] Accordingly, the welding quality of the electrode tab (6) can be inspected more accurately.

[0104] According to embodiments of the present invention, in the image acquisition process (S92), the image acquisition unit (10) can acquire the image (G) while the light irradiation unit (30) irradiates light onto one or more welded parts (W).

[0105] Accordingly, the difference in brightness or color value between one or more pixels corresponding to one or more welding points (P) and other pixels may increase. Accordingly, the welding quality of the electrode tab (6) can be accurately inspected.

[0106] According to embodiments of the present invention, in the image acquisition process (S92), the coaxial illumination (32) of the light irradiation unit (30) can irradiate light in the same direction as the image acquisition unit (10) looks at the one or more welded parts (W).

[0107] Accordingly, since the accurate surface brightness of each weld area (W) from which shadows have been removed can be obtained, the number of pixels corresponding to one or more weld points (P) can be accurately determined. Therefore, the welding quality can be accurately inspected.

[0108] According to embodiments of the present invention, the welding quality inspection method (S90) of the electrode tab may further include a region setting process (S94) in which a region setting unit (22) sets one or more regions of interest (R) that are smaller in area than the image (G) and each include one or more welding parts (W). In the pixel count calculation process (S96), the pixel count calculation unit (24) may obtain the first number from the one or more regions of interest (R).

[0109] Accordingly, the search range of valid pixels is reduced, thereby reducing the false positive rate of valid pixels. As a result, the welding quality of the electrode tab (6) can be accurately inspected.

[0110] According to embodiments of the present invention, in the pixel count calculation process (S96), the pixel count calculation unit (24) can obtain a second number of one or more valid pixels in each of the regions of interest (R). In the welding quality judgment process (S98), the welding quality judgment unit (26) can determine the welding quality of each of the welding parts (W) based on the second number in each of the regions of interest (R).

[0111] Accordingly, the welding quality of each welding area (W) of the electrode (5) and electrode tab (6) can be inspected non-destructively and automatically in a simple, rapid, and accurate manner.

[0112] According to embodiments of the present invention, in the welding quality judgment process (S98), the welding quality judgment unit (26) can determine that the overall welding quality of the electrode (5) and the electrode tab (6) is defective if the welding quality of the first welding part (W1) among the plurality of welding parts (W) is determined to be defective.

[0113] Accordingly, the welding quality of the first welded part (W1) can be ensured.

[0114] According to embodiments of the present invention, the electrode tab (6) may include an overlapping portion (62) that contacts or faces the electrode (5) and a protrusion (64) disposed on one side of the overlapping portion (62) and protruding toward the one side more than the electrode (5). The first welded portion (W1) may be the welded portion (W) located closest to the protrusion (64) among the plurality of welded portions (W).

[0115] Accordingly, the welding quality of the first welding portion (W1) closest to the protrusion (64) can be ensured. Accordingly, even if an external force is applied to the protrusion (64) of the electrode tab (6), the state in which the electrode tab (6) is welded to the electrode (5) can be stably maintained.

[0116] According to embodiments of the present invention, in the welding quality judgment process (S98), the welding quality judgment unit (26) can determine that the overall welding quality of the electrode (5) and electrode tab (6) is defective if the welding quality of m (m is a natural number smaller than n) or more welding parts (W) among n (n is a natural number greater than or equal to 2) welding parts (W) is determined to be defective.

[0117] Accordingly, the overall welding quality of the electrode (5) and the electrode tab (6) can be flexibly determined.

[0118] According to embodiments of the present invention, the m may be an integer part of the n divided by 2.

[0119] Accordingly, the overall welding quality of the electrode (5) and the electrode tab (6) can be flexibly determined.

[0120] In addition to the effects described above, the specific effects of the present invention are described together with the specific details for implementing the invention below.

[0121] FIG. 1 is a schematic diagram showing a welding quality inspection device for an electrode tab according to one embodiment of the present invention.

[0122] Figure 2 is a block diagram of the data processing unit of Figure 1.

[0123] Figure 3 is a diagram showing an image acquired by the image acquisition unit of Figure 1.

[0124] Figure 4 is an enlarged view of the dotted rectangular portion of the image in Figure 3.

[0125] FIGS. 5 to 8 are enlarged drawings of four regions of interest for the four welded parts of FIG. 4.

[0126] FIG. 9 is a schematic diagram showing an ultrasonic welding machine according to one embodiment of the present invention.

[0127] FIG. 10 is a flowchart of a welding quality inspection method for an electrode tab according to one embodiment of the present invention.

[0128] 1: Welding quality inspection device for electrode tabs

[0129] 5: Electrode 6: Electrode tab

[0130] 62: Overlapping section 64: Protrusion

[0131] 7: Electrode active material layer

[0132] W: Welded area W1: First welded area

[0133] U: Unit weld area P: Weld point

[0134] 10: Image acquisition unit

[0135] G: Image R: Area of ​​interest

[0136] 20: Data processing unit 22: Area setting unit

[0137] 24: Pixel count calculation unit 26: Welding quality judgment unit

[0138] 30: Light irradiation section 32: Coaxial illumination

[0139] 34: Half Mirror

[0140] 80: Ultrasonic welder

[0141] 82: Anvil 84: Welding horn

[0142] T: Pressure point

[0143] The aforementioned objectives, features, and advantages are described in detail below with reference to the attached drawings, thereby enabling those skilled in the art to easily implement the technical concept of the present invention. In describing the present invention, detailed descriptions of known technologies related to the present invention are omitted if it is determined that such descriptions would unnecessarily obscure the essence of the invention. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0144] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0145] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0146] In the following, the statement that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0147] In addition, where it is stated that one component is "connected," "combined," or "connected" to another component, it should be understood that while the components may be directly connected or connected to each other, another component may be "interposed" between each component, or each component may be "connected," "combined," or "connected" through another component.

[0148] Singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "composed of" or "comprising" should not be interpreted as necessarily including all of the various components or steps described in the specification, and should be interpreted as meaning that some of the components or steps may be omitted or additional components or steps may be included.

[0149] FIG. 1 is a schematic diagram showing a welding quality inspection device for an electrode tab according to an embodiment of the present invention. FIG. 2 is a block diagram of the data processing unit of FIG. 1. FIG. 3 is a diagram showing an image acquired by the image acquisition unit of FIG. 1. FIG. 4 is an enlarged view of the dotted rectangular portion of the image in FIG. 3. FIG. 5 to 8 are enlarged views of four regions of interest for four welding parts of FIG. 4. FIG. 9 is a schematic diagram showing an ultrasonic welder according to an embodiment of the present invention. FIG. 10 is a flowchart of a welding quality inspection method for an electrode tab according to an embodiment of the present invention.

[0150] [Welding quality inspection device for electrode tabs]

[0151] Referring to FIG. 1, a welding quality inspection device (1) for an electrode tab according to one embodiment may include an image acquisition unit (10) and a data processing unit (20). The welding quality inspection device (1) for an electrode tab may further include a light irradiation unit (30).

[0152] The image acquisition unit (10) may be a camera. The image acquisition unit (10) may acquire an image (G) of one or more welded parts (W) of the electrode (5) and the electrode tab (6) (Figs. 3 and 4). For example, the image acquisition unit (10) may acquire a two-dimensional image.

[0153] Here, the electrode (5) may be a sheet-type electrode. The sheet-type electrode may be wound into a jelly roll shape. An electrode tab (6) may be welded to an area (uncoated portion) of the electrode (5) where the electrode active material layer (7) is not coated.

[0154] The electrode tab (6) may include an overlapping portion (62) and a protrusion (64) (Fig. 4). The overlapping portion (62) may be in contact with or facing the electrode (5). One or more welded portions (W) may be formed in the overlapping portion (62). The protrusion (64) may be positioned on one side of the overlapping portion (62) and may protrude toward said side beyond the electrode (5).

[0155] Additionally, here, one or more welded parts (W) may be formed separately from one another. Each welded part (W) may include one or more weld points (P). One or more weld points (P) may be points where the electrode (5) and the electrode tab (6) are actually welded. The area of ​​each weld point (P) may be smaller than the area of ​​each welded part (W) and each unit welded part (U) described later.

[0156] For example, each welded portion (W) may include a plurality (e.g., 18) unit welded portions (U) (Figs. 5 to 8). The plurality of unit welded portions (U) may be spaced apart from each other. Each of the plurality of unit welded portions (U) may include a portion of one or more weld points (P). That is, each unit welded portion (U) may include one or more weld points (P) (Figs. 4 to 8). The plurality of unit welded portions (U) may be formed by a plurality of pressure points (T) protruding from the tip of the weld horn (84) during ultrasonic welding (Fig. 9).

[0157] Referring further to FIG. 2, the data processing unit (20) may include a pixel count calculation unit (24) and a welding quality judgment unit (26). The data processing unit (20) may further include an area setting unit (22).

[0158] The region setting unit (22) can recognize one or more welded parts (W) in the image (G). The region setting unit (22) can set one or more regions of interest (R) in the image (G). Each region of interest (R) may have a smaller area than the image (G). Each of the one or more regions of interest (R) may include one or more welded parts (W) (Fig. 4). The one or more regions of interest (R) may be set to be separated from each other.

[0159] The pixel count calculation unit (24) can obtain a first number of one or more valid pixels in an image (G) in which the brightness value or color value satisfies a predetermined condition. The pixel count calculation unit (24) can obtain the first number in the whole or a part (e.g., a region of interest) of the image (G). Here, the color value may be an RGB value. The brightness value or color value of one or more pixels corresponding to one or more weld points (P) in the image (G) may satisfy the predetermined condition.

[0160] In one embodiment, a predetermined condition may be that the brightness value or color value of a pixel falls within a predetermined range or matches a predetermined value. The predetermined range may be set based on the brightness value or color value of a plurality of pixels corresponding to one or more weld points (P) or to an adjacent area of ​​one or more weld points (P). The predetermined value may be the brightness value or color value of one or more pixels corresponding to one or more weld points (P).

[0161] In another embodiment, a predetermined condition may be based on the difference in brightness or color values ​​between one or more pixels corresponding to one or more welding points (P) and a plurality of surrounding pixels. For example, the predetermined condition may be a case where the difference in brightness or color values ​​between a pixel and its surrounding pixels is greater than a predetermined value.

[0162] The pixel count calculation unit (24) can obtain the first number from one or more regions of interest (R). Accordingly, the search range of valid pixels is reduced, thereby reducing the false positive rate of valid pixels. As a result, the welding quality of the electrode tab (6) can be accurately inspected.

[0163] The pixel count calculation unit (24) can obtain a second number of one or more valid pixels in each region of interest (R).

[0164] The welding quality judgment unit (26) can determine the welding quality of one or more welding parts (W) based on the first number.

[0165] For example, the welding quality judgment unit (26) can determine the welding quality of one or more welded parts (W) by comparing the first number with a reference value. Here, the reference value may be set in advance. Specifically, for example, the welding quality judgment unit (26) can determine the welding quality of one or more welded parts (W) as defective if the second number is less than the reference value (e.g., 170), and determine the welding quality of one or more welded parts (W) as normal if the second number is greater than or equal to the reference value.

[0166] In this way, the welding quality inspection device (1) of the electrode tab includes an image acquisition unit (10) and a data processing unit (20), and the data processing unit (20) may include a pixel count calculation unit (24) and a welding quality judgment unit (26). Accordingly, since the welding quality is determined by the number of pixels corresponding to one or more actual weld points (P), the welding quality of the electrode tab (6) can be inspected non-destructively and automatically in a simple, rapid, and accurate manner.

[0167] In addition, since it can replace conventional welding quality inspections (self inspection, sampling inspection, destructive inspection), the manufacturing cost of the electrode (5) can be reduced. Here, the self inspection and / or sampling inspection may be a destructive inspection in which a worker or others pull the electrode tab (6) or the electrode (5) to measure the tensile strength of one or more welded parts (W).

[0168] At this time, as described above, each welded part (W) may include a plurality of unit welded parts (U).

[0169] Accordingly, even if each welded part (W) includes multiple unit welded parts (U), the welding quality can be determined by the number of pixels corresponding to multiple weld points (P) without considering the characteristics of the multiple unit welded parts (U). Accordingly, the welding quality of the electrode tab (6) can be inspected simply, quickly, and accurately.

[0170] In contrast, judging welding quality based on the (average) size of multiple unit welding areas (U) increases the amount of calculation. Furthermore, since it is difficult to accurately calculate the size of each unit welding area (U) and some inner areas of each unit welding area (U) may not actually be welded, judging welding quality based on the (average) size of multiple unit welding areas (U) may result in lower accuracy in determining welding quality.

[0171] Also, at this time, the welding may be ultrasonic welding and one or more welding points (P) may be points where the electrode (5) and the electrode tab (6) are pressure-fused by the welding horn (84) (Fig. 9).

[0172] Accordingly, the welding quality of the electrode tab (6) can be inspected more accurately. Specifically, since the electrode (5) and the electrode tab (6) are pressure-fused by the welding horn (84) of the ultrasonic welder (80) at one or more welding points (P), the surface of the electrode (5) or the electrode tab (6) may be sloped or the density may change at one or more welding points (P). Accordingly, the brightness value or color value of the pixel corresponding to one or more welding points (P) may be clearly different from the brightness value or color value of other pixels. For example, the brightness value or color value of the pixel corresponding to the welding point (P) may be significantly smaller than that of other pixels. Therefore, the number of pixels corresponding to one or more welding points (P) can be accurately determined, so the welding quality can be inspected accurately.

[0173] However, it is not limited to this configuration. That is, the welding may be laser welding, and one or more welding points (P) may be points where a weld bead of the laser welding is formed.

[0174] Also, at this time, the electrode (5) to which the electrode tab (6) is welded may be a single sheet-type electrode.

[0175] Accordingly, the welding quality of the electrode tab (6) can be inspected more accurately. Specifically, for example, a single sheet-type electrode (5) has a small thickness, so it can easily deform together with the electrode tab (6) during welding, causing it to tilt or change density. Therefore, the brightness value or color value of one or more pixels corresponding to one or more welding points (P) can be clearly different from the brightness value or color value of other pixels. For example, the brightness value or color value of one or more pixels corresponding to one or more welding points (P) can be significantly reduced. Accordingly, the number of one or more pixels corresponding to one or more welding points (P) can be accurately determined, so the welding quality can be inspected accurately.

[0176] The welding quality judgment unit (26) can determine the welding quality of each welding part (W) based on the second number in each area of ​​interest (R).

[0177] Accordingly, the welding quality of each welding area (W) of the electrode (5) and electrode tab (6) can be inspected non-destructively and automatically in a simple, rapid, and accurate manner.

[0178] The welding quality judgment unit (26) can determine that the overall welding quality of the electrode (5) and the electrode tab (6) is defective if the welding quality of the first welding part (W1) among the plurality of welding parts (W) is determined to be defective.

[0179] For example, if the number of effective pixels (second number) of the region of interest (R) corresponding to the first welding area (W1) is smaller than the reference value and the welding quality of the first welding area (W1) is determined to be poor, the welding quality judgment unit (26) can determine the overall welding quality of the electrode (5) and the electrode tab (6) to be poor.

[0180] Accordingly, the welding quality of the first welded part (W1) can be ensured.

[0181] Here, the first welded portion (W1) may be the welded portion (W) located closest to the protrusion (64) of the electrode tab (6) among the plurality of welded portions (W) (Fig. 4).

[0182] Accordingly, the welding quality of the first welding portion (W1) closest to the protrusion (64) can be ensured. Accordingly, even if an external force is applied to the protrusion (64) of the electrode tab (6), the state in which the electrode tab (6) is welded to the electrode (5) can be stably maintained.

[0183] The welding quality judgment unit (26) can determine that the overall welding quality of the electrode (5) and the electrode tab (6) is defective if the welding quality of m (m is a natural number smaller than n) or more welding parts (W) among n (n is a natural number greater than or equal to 2) welding parts (W) is determined to be defective. For example, the welding quality judgment unit (26) can determine that the overall welding quality of the electrode (5) and the electrode tab (6) is defective if the number of effective pixels (second number) of each of m or more regions of interest (R) corresponding to each of m or more first welding parts (W1) is smaller than the reference value.

[0184] Accordingly, the overall welding quality of the electrode (5) and the electrode tab (6) can be flexibly determined.

[0185] Here, m may be an integer part of n divided by 2. For example, n=4 and m=2. Accordingly, the overall welding quality of the electrode (5) and the electrode tab (6) can be flexibly determined.

[0186] The light irradiation unit (30) can irradiate light onto one or more welded parts (W). While the light irradiation unit (30) is irradiating light onto one or more welded parts (W), the image acquisition unit (10) can acquire an image (G).

[0187] Accordingly, the difference in brightness or color value between one or more pixels corresponding to one or more welding points (P) and other pixels may increase. Accordingly, the welding quality of the electrode tab (6) can be accurately inspected.

[0188] For example, if light is shone on each welded area (W) that is generally flat but has only one or more weld points (P) that are inclined (concave or convex), one or more weld points (P) can be clearly darkened. Accordingly, the number of pixels corresponding to one or more weld points (P) can be accurately determined, so the welding quality of the electrode tab (6) can be accurately inspected.

[0189] The light irradiation unit (30) may include a coaxial light (32). The coaxial light (32) may irradiate light in the same direction as the image acquisition unit (10) is facing one or more welded parts (W).

[0190] Accordingly, since the accurate surface brightness of each weld area (W) from which shadows have been removed can be obtained, the number of pixels corresponding to one or more weld points (P) can be accurately determined. Therefore, the welding quality can be accurately inspected.

[0191] For example, the coaxial light (32) can irradiate light in a direction substantially perpendicular to one or more welded parts (W).

[0192] The coaxial light (32) may include a half mirror (34). For example, light from the light source may be reflected through the half mirror (34) toward one or more welded parts (W), and light that reaches one or more welded parts (W) may be reflected to reach the image acquisition unit (10) (Fig. 1).

[0193] Referring to FIG. 9, an ultrasonic welder (80) according to one embodiment may include an anvil (82) and a welding horn (84). An electrode (5) and an electrode tab (6) are placed between the anvil (82) and the welding horn (84), and the electrode (5) and the electrode tab (6) can be welded (fused) by ultrasonically vibrating the welding horn (84) while pressing it toward the anvil (82). A plurality of unit welded portions (U) may be formed by a plurality of pressure points (T) protruding from the tip of the welding horn (84).

[0194] [Inspection Method for Welding Quality of Electrode Tabs]

[0195] Referring to FIG. 10, a welding quality inspection method (S90) of an electrode tab according to one embodiment may include an image acquisition process (S92), a pixel count calculation process (S96), and a welding quality judgment process (S98). The welding quality inspection method (S90) of an electrode tab may further include a region setting process (S94).

[0196] In the image acquisition process (S92), the image acquisition unit (10) can acquire an image (G) of the welded portion (W) of the electrode (5) and the electrode tab (6).

[0197] Additionally, the image acquisition unit (10) can acquire an image (G) while the light irradiation unit (30) irradiates light onto one or more welded parts (W). Accordingly, the difference in brightness or color value between one or more pixels corresponding to one or more welded points (P) and other pixels can be increased. Accordingly, the welding quality of the electrode tab (6) can be accurately inspected.

[0198] Here, the coaxial illumination (32) of the light irradiation unit (30) can irradiate light in the same direction as the image acquisition unit (10) is facing one or more welded parts (W). Accordingly, since the accurate surface brightness of each welded part (W) with shadows removed can be obtained, the number of pixels corresponding to one or more welded points (P) can be accurately determined. Therefore, the welding quality can be accurately inspected.

[0199] In the region setting process (S94), the region setting unit (22) can set one or more regions of interest (R) as described above in the image (G).

[0200] In the pixel count calculation process (S96), the pixel count calculation unit (24) can obtain a first number of one or more effective pixels in the image (G) in which the brightness value or color value satisfies the aforementioned predetermined condition.

[0201] Additionally, the pixel count calculation unit (24) can obtain the first number from one or more regions of interest (R). Accordingly, the search range of valid pixels is reduced, thereby reducing the false positive rate of valid pixels. As a result, the welding quality of the electrode tab (6) can be accurately inspected.

[0202] Additionally, the pixel count calculation unit (24) can obtain a second number of one or more valid pixels in each region of interest (R).

[0203] In the welding quality judgment process (S98), the welding quality judgment unit (26) can determine the welding quality of the welding area (W) based on the number of effective pixels (first number).

[0204] In this way, the welding quality inspection method (S90) of the electrode tab may include an image acquisition process (S92), a pixel count calculation process (S96), and a welding quality judgment process (S98). Accordingly, since the welding quality is determined by the number of pixels corresponding to one or more actual weld points (P), the welding quality of the electrode tab (6) can be inspected automatically and non-destructively in a simple, rapid, and accurate manner. Furthermore, since it can replace conventional welding quality inspections (self inspection, sampling inspection, destructive inspection), the manufacturing cost of the electrode (5) can be reduced.

[0205] At this time, each welded portion (W) may include a plurality of unit welded portions (U). Accordingly, the welding quality of the electrode tab (6) can be inspected simply, quickly, and accurately.

[0206] In addition, at this time, the welding is ultrasonic welding, and one or more welding points (P) may be points where the electrode (5) and the electrode tab (6) are pressure-fused by the welding horn (84). Accordingly, the welding quality of the electrode tab (6) can be inspected more accurately.

[0207] In addition, at this time, the electrode (5) to which the electrode tab (6) is welded may be a single sheet-type electrode. Accordingly, the welding quality of the electrode tab (6) can be inspected more accurately.

[0208] In addition, the welding quality judgment unit (26) can determine the welding quality of each welding part (W) based on the number of valid pixels (second number) in each region of interest (R). Accordingly, the welding quality of each welding part (W) of the electrode (5) and electrode tab (6) can be inspected non-destructively and automatically in a simple, rapid, and accurate manner.

[0209] In addition, the welding quality judgment unit (26) can determine that the overall welding quality of the electrode (5) and the electrode tab (6) is defective if the welding quality of the first welding part (W1) among the plurality of welding parts (W) is determined to be defective. Accordingly, the welding quality of the first welding part (W1) can be secured.

[0210] Here, the first welded portion (W1) may be the welded portion (W) located closest to the aforementioned protrusion (64) among the plurality of welded portions (W). Accordingly, the welding quality of the first welded portion (W1) closest to the protrusion (64) can be ensured. Accordingly, even if an external force is applied to the protrusion (64) of the electrode tab (6), the state in which the electrode tab (6) is welded to the electrode (5) can be stably maintained.

[0211] Additionally, the welding quality judgment unit (26) can determine that the overall welding quality of the electrode (5) and the electrode tab (6) is defective if the welding quality of m (m is a natural number smaller than n) or more of the welding parts (W) among n (n is a natural number greater than or equal to 2) is determined to be defective. Accordingly, the overall welding quality of the electrode (5) and the electrode tab (6) can be flexibly determined.

[0212] Here, m may be an integer part of n divided by 2. Accordingly, the overall welding quality of the electrode (5) and the electrode tab (6) can be flexibly determined.

[0213] The embodiments described above should be understood as exemplary in all respects and not limiting, and the scope of the invention will be defined by the claims set forth below rather than by the detailed description above. Furthermore, the meaning and scope of the claims set forth below, as well as all modifications and variations derived from equivalents thereof, should be interpreted as being included within the scope of the invention.

[0214] Although the present invention has been described above with reference to the illustrated drawings, the present invention is not limited by the embodiments and drawings disclosed in this specification, and it is obvious that various modifications can be made by a person skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration according to the present invention were not explicitly described while describing the embodiments of the present invention above, it is natural to acknowledge that the effects predictable by said configuration should also be recognized.

Claims

1. An image acquisition unit (10) that acquires an image (G) of one or more welded portions (W) of an electrode (5) and an electrode tab (6); A pixel count calculation unit (24) for calculating a first number of one or more effective pixels in which a brightness value or color value satisfies a predetermined condition in the above image (G); and It includes a welding quality judgment unit (26) that determines the welding quality of one or more welding parts (W) based on the first number above, and Each of the above-mentioned welded portions (W) includes one or more weld points (P) where the electrode (5) and the electrode tab (6) are actually welded, and The brightness value or color value of one or more pixels corresponding to one or more welding points (P) above satisfies the above predetermined condition, Welding quality inspection device for electrode tabs.

2. In Claim 1, A welding quality inspection device for an electrode tab, wherein each of the above-mentioned welding portions (W) comprises a plurality of unit welding portions (U) that are spaced apart from each other and each include a portion of one or more of the above-mentioned welding points (P).

3. In claim 1 or claim 2, The above welding is ultrasonic welding, and A welding quality inspection device for an electrode tab, wherein one or more welding points (P) are points where the electrode (5) and the electrode tab (6) are pressure-fused by a welding horn (84).

4. In any one of claims 1 to 3, The electrode (5) to which the electrode tab (6) is welded is a single sheet-type electrode, and the electrode tab welding quality inspection device.

5. In any one of claims 1 to 4, It further includes a light irradiation unit (30) that irradiates light onto one or more welded parts (W) above, and The light irradiation unit (30) includes a coaxial light (32) that irradiates light in the same direction as the image acquisition unit (10) looks at the one or more welded parts (W). A welding quality inspection device for an electrode tab, wherein the image acquisition unit (10) acquires the image (G) while the light irradiation unit (30) irradiates light onto one or more welding parts (W).

6. In any one of claims 1 to 5, The above image (G) further includes a region setting unit (22) for setting one or more regions of interest (R) that are smaller in area than the image (G) and each include one or more welded parts (W). The above pixel count calculation unit (24) is a welding quality inspection device for an electrode tab that calculates the first number in one or more regions of interest (R).

7. In Claim 6, The pixel count calculation unit (24) calculates a second number of one or more valid pixels in each of the regions of interest (R), and The above welding quality judgment unit (26) is a welding quality inspection device for an electrode tab that determines the welding quality of each welding part (W) based on the second number in each of the areas of interest (R).

8. In Claim 7, The welding quality judgment unit (26) above is a welding quality inspection device for an electrode tab, which determines the overall welding quality of the electrode (5) and the electrode tab (6) as defective if the welding quality of the first welding part (W1) among the plurality of welding parts (W) is determined to be defective.

9. In Claim 8, The electrode tab (6) comprises an overlapping portion (62) that contacts or faces the electrode (5) and a protrusion (64) disposed on one side of the overlapping portion (62) and protruding toward the one side more than the electrode (5). The above first welding portion (W1) is the welding portion (W) located closest to the protrusion (64) among the plurality of welding portions (W), in the electrode tab welding quality inspection device.

10. In any one of claims 7 to 9, The welding quality judgment unit (26) above determines that if the welding quality of m (m is a natural number smaller than n) or more of the welding parts (W) among n (n is a natural number greater than or equal to 2) of the welding parts (W) is determined to be defective, the overall welding quality of the electrode (5) and the electrode tab (6) is determined to be defective.

11. A welding quality inspection method (S90) of an electrode tab using the welding quality inspection device (1) of claim 1, An image acquisition process (S92) in which the image acquisition unit (10) acquires the image (G) of the one or more welded portions (W) of the electrode (5) and the electrode tab (6); A pixel count calculation process (S96) in which the pixel count calculation unit (24) calculates the first number of one or more valid pixels in the image (G) in which the brightness value or color value satisfies the predetermined condition; and The above welding quality judgment unit (26) includes a welding quality judgment process (S98) that determines the welding quality of one or more welding parts (W) based on the above first number, and Each of the above-mentioned welded portions (W) includes one or more weld points (P) where the electrode (5) and the electrode tab (6) are actually welded, and In the above image (G), the brightness value or color value of one or more pixels corresponding to one or more weld points (P) satisfies the above predetermined condition. Inspection method for welding quality of electrode tabs.

12. In Claim 11, A welding quality inspection method for an electrode tab, wherein each of the above-mentioned welding portions (W) comprises a plurality of unit welding portions (U) that are spaced apart from each other and each include a portion of one or more of the above-mentioned welding points (P).

13. In claim 11 or claim 12, The above welding is ultrasonic welding, and A welding quality inspection method for an electrode tab, wherein one or more welding points (P) are points where the electrode (5) and the electrode tab (6) are pressure-fused by a welding horn (84).

14. In any one of claims 11 to 13, A welding quality inspection method for an electrode tab, wherein the electrode (5) to which the electrode tab (6) is welded is a single sheet-type electrode.

15. In any one of claims 11 to 14, A welding quality inspection method for an electrode tab, wherein in the above image acquisition process (S92), the image acquisition unit (10) acquires the image (G) while the coaxial illumination (32) of the light irradiation unit (30) irradiates light onto one or more welded parts (W) in the same direction as the direction in which the image acquisition unit (10) looks at one or more welded parts (W).

16. In any one of claims 11 to 15, The region setting unit (22) further includes a region setting process (S94) for setting one or more regions of interest (R) that are smaller in area than the image (G) and each include one or more welded parts (W) in the image (G). In the above pixel count calculation process (S96), the pixel count calculation unit (24) calculates the first number in one or more regions of interest (R), a welding quality inspection method for electrode tabs.

17. In Claim 16, In the pixel count calculation process (S96) above, the pixel count calculation unit (24) calculates a second number of one or more valid pixels in each of the regions of interest (R), and In the above welding quality judgment process (S98), the welding quality judgment unit (26) determines the welding quality of each welding part (W) based on the second number in each of the areas of interest (R), a welding quality inspection method for electrode tabs.

18. In Claim 17, A welding quality inspection method for electrode tabs, wherein in the welding quality judgment process (S98) above, the welding quality judgment unit (26) determines that if the welding quality of the first welding part (W1) among the plurality of welding parts (W) is determined to be poor, the overall welding quality of the electrode (5) and electrode tab (6) is determined to be poor.

19. In Claim 18, The electrode tab (6) comprises an overlapping portion (62) that contacts or faces the electrode (5) and a protrusion (64) disposed on one side of the overlapping portion (62) and protruding toward the one side more than the electrode (5). A welding quality inspection method for an electrode tab, wherein the first welding portion (W1) is the welding portion (W) located closest to the protrusion (64) among the plurality of welding portions (W).

20. In any one of claims 17 to 19, A welding quality inspection method for an electrode tab, wherein in the welding quality judgment process (S98) above, the welding quality judgment unit (26) determines that the overall welding quality of the electrode (5) and the electrode tab (6) is defective if the welding quality of m (m is a natural number smaller than n) or more welding parts (W) among n (n is a natural number greater than or equal to 2) welding parts (W) is determined to be defective.

Images