Welding apparatus

Abstract

A welding apparatus according to an embodiment of the present invention comprises: a main jig supporting at least a portion of an object to be welded; a laser generating device irradiating a laser to the object to be welded, to weld the object to be welded; and a protective jig extending in one direction and disposed on an opposite side with respect to the laser generating device with respect to the object to be welded. The protective jig includes a first area corresponding to an area to which the laser is irradiated onto the object to be welded and a second area other than the first area, and the area of a first cross section cut in a direction orthogonal to the one direction in the first area of the protective jig may be smaller than the area of a second cross section cut in the second area.

Description

welding device

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0202296 filed December 31, 2024 and Korean Patent Application No. 10-2025-0209523 filed December 24, 2025, and all contents disclosed in the documents of said Korean patent applications are incorporated herein as part of this specification.

[0003] The present invention relates to a welding device, and more specifically, to a welding device comprising a protective jig capable of preventing thermal deformation caused by a laser while protecting the lower surface of a workpiece.

[0004] In modern society, as the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras, as well as energy storage systems (ESS), has become commonplace, the development of technologies in related fields is becoming active. Furthermore, rechargeable secondary batteries are being utilized as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) as a solution to address air pollution caused by conventional gasoline vehicles using fossil fuels; consequently, the need for the development of secondary batteries is increasing.

[0005] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are receiving the most attention due to their advantages of free charging and discharging, low self-discharge rate, and high energy density.

[0006] In the case of secondary batteries used in small devices, 2 to 3 battery cells are arranged, whereas in the case of secondary batteries used in medium to large devices such as automobiles, battery modules in which multiple battery cells are electrically connected are used. In such battery modules, capacity and output are improved by connecting multiple battery cells in series or parallel to form a stack of battery cells. In addition, one or more battery modules can be mounted together with various control and protection systems, such as a Battery Disconnect Unit (BDU), a Battery Management System (BMS), and a cooling system, to form a battery pack.

[0007] To electrically connect multiple battery cells, electrical connections are required between the electrode leads of the cells, between busbars, or with the battery module. Generally, welding, such as laser welding, can be used to electrically connect these. In this case, the workpiece must be fully penetrated to ensure sufficient weld strength. However, when applying through-welding, a problem may arise where the laser comes into contact with additional structures or the workpiece on the underside of the workpiece.

[0008] The problem that the present invention aims to solve is to provide a welding device including a protective jig that can prevent thermal deformation caused by a laser while protecting the lower surface of the workpiece.

[0009] However, the problems that the embodiments of the present invention aim to solve are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention.

[0010] A welding device according to one embodiment of the present invention comprises a main jig that supports at least a portion of a workpiece, a laser generating device that irradiates a laser onto the workpiece to perform welding, and a protective jig that extends in one direction and is positioned on the opposite side of the laser generating device with respect to the workpiece, wherein the protective jig comprises a first region corresponding to the area where the laser is irradiated on the workpiece and a second region excluding the first region, and the area of ​​a first cross-section obtained by cutting the protective jig in a direction orthogonal to the one direction in the first region may be smaller than the area of ​​a second cross-section obtained by cutting the second region.

[0011] The first cross section may include an empty space formed by being spaced apart from each of the two sides of the protective jig by a predetermined distance.

[0012] The above protective jig may include a groove portion that is recessed from the surface facing the workpiece in the first region to form the empty space.

[0013] The above groove can be extended along the above one direction.

[0014] The above-mentioned groove may include an opening that is opened on one end or both ends of the protective jig based on the above-mentioned direction.

[0015] It may further include a protective member that is replaceably inserted into the groove of the above protective jig.

[0016] The above protective jig and the above protective member may be formed of different materials.

[0017] The above protective jig is formed of a ceramic material, and the above protective member may be formed of a metal material.

[0018] The above protective jig may include a hollow portion that forms the empty space inside the first region.

[0019] The above hollow part may not be in communication with the outside of the above protective jig.

[0020] The cross-section of the above empty space may be rectangular.

[0021] When the direction in which the laser is irradiated is called the vertical direction and the direction perpendicular thereto is called the horizontal direction, the ratio of the vertical length of the empty space to the vertical length of the protective jig may be 0.43 to 0.8.

[0022] When the direction in which the laser is irradiated is called the vertical direction and the direction perpendicular thereto is called the horizontal direction, the ratio of the horizontal length of the empty space to the horizontal length of the protective jig may be 0.3 to 0.6.

[0023] The above protective jig may include a main body portion extending in one direction and including the first region, and a fastening portion fixedly coupled to the main jig.

[0024] The above protective jig can be replacedly coupled to the above main jig.

[0025] The main jig may include a guide groove formed by being recessed to accommodate a part of the main body of the protective jig.

[0026] Both sides of the above protective jig can be supported by the guide grooves of the above main jig.

[0027] The above protective jig can be fixed to the main jig through the fastening part after the main body part is inserted into the guide groove of the main jig.

[0028] The above protective jig may include at least one of a metal material and a ceramic material.

[0029] A welding device according to embodiments of the present invention is provided with a protective jig so that when a laser generated by a laser generating device penetrates a workpiece, the laser can be prevented from being irradiated onto a part other than the workpiece.

[0030] The protective jig can minimize localized thermal deformation in the protective jig by forming an empty space inside the first area, which is spaced apart by a predetermined distance from each of the two sides of the protective jig, where a laser penetrating the workpiece is irradiated.

[0031] In addition, the protective jig is slidably coupled to the main jig, making it easy to insert and remove the protective jig, and since both sides of the protective jig are supported by guide grooves, deformation of the protective jig can be further minimized.

[0032] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims.

[0033] FIG. 1 is a perspective view of a secondary battery according to one embodiment of the present invention.

[0034] FIG. 2 is a front view of a welding device according to one embodiment of the present invention.

[0035] FIG. 3 is a top view showing the main jig and protective jig illustrated in FIG. 2 from the top.

[0036] FIG. 4 is a top view illustrating an example of a protective jig shown in FIG. 2.

[0037] Figure 5 is a perspective view of the protective jig shown in Figure 4.

[0038] Figure 6 is a cross-sectional view showing a cross-section cut along the cutting line A-A' of Figure 5.

[0039] Figure 7 is a graph to explain the amount of deformation of the protective jig according to the shape of the empty space shown in Figure 6.

[0040] FIG. 8 is a top view showing the main jig and the protective jig from above to explain another example of the protective jig shown in FIG. 4.

[0041] FIG. 9 is a top view illustrating another example of the protective jig shown in FIG. 8.

[0042] FIG. 10 is a perspective view of the protective jig shown in FIG. 9.

[0043] FIG. 11 is a perspective view illustrating another example of the protective jig shown in FIG. 4.

[0044] FIG. 12 is a cross-sectional view showing a cross-section cut along the cutting line B-B' of FIG. 11.

[0045] FIG. 13 is a perspective view illustrating another example of the protective jig shown in FIG. 4.

[0046] Figure 14 is a cross-sectional view showing a cross-section cut along the cutting line C-C' of Figure 13.

[0047] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0048] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0049] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0050] Furthermore, when a part such as a layer, membrane, region, or plate is said to be "on" or "on" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Also, saying that a part is "on" or "on" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "on" or "on" facing the opposite direction of gravity.

[0051] In addition, terms indicating directions such as front, back, left, right, up, and down have been used; however, these terms are merely for the convenience of explanation and may vary depending on the location of the object or the observer.

[0052] Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0053] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0054] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0055] FIG. 1 is a perspective view of a secondary battery according to one embodiment of the present invention.

[0056] Referring to FIG. 1, a secondary battery (10) according to one embodiment of the present invention may be formed by stacking a plurality of battery cells (11). The battery cell (11) may be a pouch-type battery in which an electrode assembly having electrode leads (20) protruding in one or both directions is housed in a pouch case. However, this is merely an example, and the battery cell according to another embodiment of the present invention may be a prismatic battery. For convenience of explanation, the following description will be based on a battery cell (11) that is a pouch-type battery.

[0057] The battery cell (11) may have a rectangular sheet shape. The battery cell (11) may be formed by housing an electrode assembly in a pouch case of a laminate sheet comprising a resin layer and a metal layer, and then bonding the outer periphery of the pouch case. As an example, the battery cell (11) may be manufactured by bonding the periphery of the pouch case while housing an electrode assembly (not shown) in the pouch case. As another example, the battery cell (11) may be formed by housing the electrode assembly while one side of the pouch case is folded and sealing the remaining sides.

[0058] As illustrated in FIG. 1, the battery cell (11) may have a structure in which two electrode leads (20) protrude from each end of the cell body facing each other. However, the portion of the protruding electrode leads (20) is not limited to what is described above. As another embodiment, a structure in which all electrode leads (20) of the battery cell (11) protrude in one direction is also possible. In this case, one of the electrode leads (20) is a positive lead and the other is a negative lead.

[0059] A plurality of electrode leads (20) protruding from a plurality of battery cells (11) can be welded together for electrical connection. For example, the plurality of electrode leads (20) can be welded together by a welding process such as ultrasonic welding or laser welding. However, the objects to which the electrode leads (20) are welded are not limited to those described above. For example, the electrode leads (20) can be connected to at least one of a busbar, a battery module, or a battery pack.

[0060] Additionally, although not illustrated, the electrode assembly may include a plurality of electrodes stacked with a separator in between, and a plurality of electrode tabs connected to the plurality of electrodes and welded together. The plurality of electrode tabs may be connected to the plurality of electrodes and welded together. The plurality of electrode tabs may be welded together by a welding process such as ultrasonic welding or laser welding. An electrode lead (20) may be connected to the electrode tabs. The electrode lead (20) may be welded together to the plurality of electrode tabs by a welding process such as laser welding. The electrode lead (20) may be welded over the welded portion where the plurality of electrode tabs are welded together.

[0061] When a plurality of electrode tabs and a plurality of electrode leads (20) are welded, the welding may be performed by laser welding using a welding device (100) according to an embodiment of the present invention described below, and a detailed description of the welding device (100) will be provided later.

[0062] FIG. 2 is a front view of a jig assembly according to an embodiment of the present invention. FIG. 3 is a top view showing the main jig and protective jig shown in FIG. 2 from above. FIG. 4 is a top view showing an example of the protective jig shown in FIG. 2. FIG. 5 is a perspective view of the protective jig shown in FIG. 4. FIG. 6 is a cross-sectional view showing a cross section cut along the cutting line A-A' of FIG. 5. FIG. 7 is a graph for explaining the amount of deformation of the protective jig according to the shape of the empty space shown in FIG. 6.

[0063] Referring to FIGS. 2 to 7, a welding device (100) according to one embodiment of the present invention may include a main jig (110) that supports at least a part of a workpiece (20), a laser generating device (130) that irradiates a laser onto the workpiece (20) to perform welding, and a protective jig (140) that extends in one direction and is positioned on the opposite side of the laser generating device (130) with respect to the workpiece (20).

[0064] First, the workpiece (20) may be a plurality of electrode leads (20) extending from a plurality of battery cells (11). However, the workpiece (20) is not limited to what is described above, and any member that can be joined together through welding may correspond to the workpiece (20) according to the embodiment of the present invention.

[0065] The main jig (110) may be positioned in the lower direction (-z-axis direction) of the workpiece (20) to support the workpiece (20). The main jig (110) may be formed with an empty space in the lower part of the area where the laser is irradiated on the workpiece (20) to prevent the laser irradiated from the laser generator (130) from penetrating and directly contacting the workpiece (20). For example, as shown in FIG. 2, the main jig (110) may be formed in a U-shape to support both sides (y-axis direction and -y-axis direction) of the workpiece (20).

[0066] If the workpiece (20) moves or becomes misaligned during the welding process, the accuracy of the welding may decrease. To prevent this, the welding device (100) may include an upper jig (120) positioned in the upper direction (z-axis direction) of the workpiece (20). The workpiece (20) may be positioned between the main jig (110) and the upper jig (120). At least one of the main jig (110) and the upper jig (120) is vertically movable, and accordingly, the workpiece (20) can be fixed by being pressed by the main jig (110) and the upper jig (120).

[0067] The upper jig (120) can be positioned at a location corresponding to where the main jig (110) supports the workpiece (20). For example, as shown in FIG. 2, the upper jig (120) can be positioned to press both sides (y-axis direction and -y-axis direction) of the workpiece (20). A laser beam irradiated from the laser generator (130) can travel through the upper jig (120) and reach the workpiece (20). Thus, welding of the workpiece (20) can be performed smoothly while the main jig (110) and the upper jig (120) hold the workpiece (20).

[0068] The laser generating device (130) may be positioned in the upper direction (z-axis direction) of the main jig (110), specifically the workpiece (20). The laser generating device (130) may include a light source that generates a laser and an optical system capable of changing the path of the laser generated from the light source, and the detailed configuration of the laser generating device (130) may be varied or changed to suit the environment in which the present invention is implemented.

[0069] The laser generating device (130) can irradiate a laser while the workpiece (20) is supported by the main jig (110). The laser of the laser generating device (130) can be irradiated onto the workpiece (20), and the workpiece (20) can be locally melted by the heat generated by the laser and welded together.

[0070] The protective jig (140) is a component for preventing the laser from being irradiated to parts other than the workpiece (20) when the laser generated by the laser generator (130) penetrates the workpiece (20). To this end, the protective jig (140) may be formed from a material that has high rigidity and can minimize thermal deformation. For example, the protective jig (140) may include at least one of a metal material and a ceramic material.

[0071] As illustrated in the example in FIG. 3, the protective jig (140) may include a first region (141a) corresponding to the area where a laser is irradiated on the workpiece (20), and a second region (141b) excluding the first region (141a). For example, the first region (141a) may be the area immediately below the area where a laser is irradiated on the workpiece (20). A laser that penetrates the workpiece (20) may be irradiated into the first region (141a).

[0072] The area of ​​the first cross-section of the protective jig (140), which is cut along a plane (yz plane) perpendicular to the direction (x direction) in which the protective jig (140) extends, may be smaller than the area of ​​the second cross-section, which is cut along the second region (141b).

[0073] The first cross section may include empty spaces (144, 145) formed at a predetermined distance from each of the two sides of the protective jig (140). On the other hand, the second cross section may be a rectangular shape in which no empty space is formed. Therefore, since the first cross section includes empty spaces (144, 145), its area may be smaller than that of the second cross section. At this time, the cross-sectional shape of the empty spaces (144, 145) may be rectangular, and preferably may be a rectangle or a square.

[0074] FIG. 7(a) is a graph showing the amount of deformation in the z-axis direction of the protective jig (140) according to the ratio of the length in the z-axis direction of the empty space (144, 145) to the length in the z-axis direction of the protective jig (140). FIG. 7(b) is a graph showing the amount of deformation in the z-axis direction of the protective jig (140) according to the ratio of the length in the y-axis direction of the empty space (144, 145) to the length in the y-axis direction of the protective jig (140). At this time, the z-axis direction is the direction in which the laser is irradiated and can be referred to as the vertical direction, and the y-axis direction is the direction perpendicular to the z-axis direction and can be referred to as the horizontal direction.

[0075] FIG. 7(a) shows a case where the ratio of the length of the empty space (144, 145) in the y-axis direction to the length of the protective jig (140) in the y-axis direction is fixed at a certain value (e.g., 0.6). As shown in FIG. 7(a), the amount of deformation in the z-axis direction of the protective jig (140) decreases as the ratio of the length in the z-axis direction increases, and then increases again after a certain period. At this time, the dotted line (baseline) shown on the graph represents the amount of deformation that occurs when no empty space is formed in the protective jig (140). Therefore, it can be seen that the deformation of the protective jig (140) decreases at a ratio of the length in the z-axis direction that satisfies the range within the baseline.

[0076] Accordingly, the ratio of the z-axis length of the empty space (144, 145) to the z-axis length of the protective jig (140) may be 0.43 to 0.8, preferably 0.44 to 0.75, and more preferably 0.44 to 0.64.

[0077] FIG. 7(b) shows a case where the ratio of the length in the z-axis direction of the empty space (144, 145) to the length in the z-axis direction of the protective jig (140) is fixed at a certain value (e.g., 0.5). As shown in FIG. 7(b), the amount of deformation in the z-axis direction of the protective jig (140) decreases as the ratio of the length in the y-axis direction increases, and then increases again after a certain period. At this time, the dotted line (baseline) shown on the graph represents the amount of deformation that occurs when no empty space is formed in the protective jig (140). Therefore, it can be seen that the deformation of the protective jig (140) decreases at a ratio of the length in the y-axis direction that satisfies the range within the baseline.

[0078] Accordingly, the ratio of the length in the y-axis direction of the empty space (144, 145) to the length in the y-axis direction of the protective jig (140) may be 0.3 to 0.6, preferably 0.32 to 0.5, and more preferably 0.35 to 0.45.

[0079] Referring again to FIGS. 4 and FIGS. 5, the protective jig (140) may include a main body part (141) extending in one direction (x-axis direction) and a fastening part (142) fixedly coupled to the main jig (110).

[0080] The main body (141) is a part that extends in the x-axis direction. The main body (141) includes a first region (141a) through which a laser penetrates and irradiates the workpiece (20). A fastening part (142) may be formed at one end of the main body (141). The fastening part (142) is a part for securely connecting the protective jig (140) and the main jig (110). The fastening part (142) may be in a shape that extends in a direction orthogonal to the direction in which the main body (141) extends (x-axis direction) (y-axis direction).

[0081] The fastening portion (142) may include at least one through hole (143). As shown in FIG. 4, two through holes (143) may be formed at each of the two ends of the fastening portion (142). However, the number and location of the through holes (143) are not limited by the above description. For example, the through holes (143) may be provided in multiple numbers and arranged along the direction in which the fastening portion (142) extends (y-axis direction).

[0082] The protective jig (140) can be fixed to the main jig (110) through the fastening portion (142). For example, the protective jig (140) can be combined with the main jig (110) by inserting a fixing part, such as a bolt, through the through hole (143) of the fastening portion (142). However, the method of combining the protective jig (140) and the main jig (110) is not limited to the method described above, and can be modified or changed in various ways to suit the environment in which the present invention is implemented.

[0083] Referring again to FIGS. 2 and FIGS. 3, the protective jig (140) can be interchangeably coupled to the main jig (110). For example, the protective jig (140) can be slidably coupled to the main jig (110), and accordingly, the protective jig (140) can be interchangeably coupled to the main jig (110). The protective jig (140) can be fixed to the main jig (110) through the fastening part (142) after the main body part (141) of the protective jig (140) is inserted into the guide groove (111) of the main jig (110).

[0084] More specifically, the main jig (110) may include a guide groove (111) formed by being recessed to accommodate a part of the main body portion (141) of the protective jig (140). The guide groove (111) may be formed by being recessed in the y-axis direction and the -y-axis direction, respectively, from the inner surface of both sides of the U-shaped main jig (110). Additionally, the guide groove (111) may extend along the extension direction (x-axis direction) of the main jig (110). Thus, the main body portion (141) of the protective jig (140) can be inserted into the guide groove (111) of the main jig (110) and slide. Accordingly, the insertion and separation of the protective jig (140) from the main jig (110) may be easy.

[0085] As the main body (141) of the protective jig (140) is inserted into the guide groove (111) of the main jig (110), both side portions of the protective jig (140) can be supported by the guide groove (111) of the main jig (110). Through this structure, since both side portions of the protective jig (140) can be supported by the main jig (110), deformation that may occur in the first region (141a) of the protective jig (140) can be further suppressed. That is, the deformation of the protective jig (140) can be minimized by suppressing deformation in the first region (141a), which has low bending rigidity and is subject to thermal influence.

[0086] As illustrated in the examples in FIGS. 4 to 6, the protective jig (140) may include a groove (144) that is recessed from the surface facing the workpiece (20) in the first region (141a) to form a void. The groove (144) may extend along one direction (x-axis direction) in which the protective jig (140) extends.

[0087] In an embodiment of the present invention, since the groove (144) of the protective jig (140) is formed on the first region (141a) at a predetermined distance from each of the two sides, the two sides of the protective jig (140) where no empty space is formed may have high rigidity and low thermal deformation. Accordingly, the two sides of the protective jig (140) can suppress thermal deformation that may occur in the first region. Therefore, it is possible to suppress deformation of the protective jig (140) caused by a laser penetrating the workpiece (20).

[0088] Specifically, thermal deformation may occur centered on a local area where a laser penetrating the workpiece (20) is irradiated. For example, thermal deformation may occur in the first area (141a) of the protective jig (140). On the other hand, the two sides of the protective jig (140) are not affected by the laser, and since no empty space (groove; 144) is formed in the two sides of the protective jig (140), the rigidity against bending is high. Therefore, the two sides of the protective jig (140) are affected by heat, and deformation in the first area (141a), which has low rigidity against bending, can be suppressed, thereby minimizing the deformation of the protective jig (140). That is, by forming a groove (144) inside the first area (141a) of the protective jig (140), it is possible to minimize locally occurring thermal deformation.

[0089] FIG. 8 is a top view showing the main jig and the protective jig from above to illustrate another example of the protective jig shown in FIG. 4. FIG. 9 is a top view showing another example of the protective jig shown in FIG. 8. FIG. 10 is a perspective view of the protective jig shown in FIG. 9.

[0090] Referring to FIGS. 8 to 10, the groove (144) may include an opening (144o) that is opened on one end or both ends of the protective jig (140) with respect to one direction (x-axis direction).

[0091] For example, as illustrated in the examples in FIGS. 9 and 10, the groove (144) may be opened at one end (upper end in the x-axis direction) of the protective jig (140) as it extends along one direction (x-axis direction). Here, the groove (144) is open in the upper direction (z-axis direction) because it is recessed from the surface facing the workpiece (20) to form a void. Thus, the meaning of the groove (144) being open at one end is that the groove (144) is opened in an additional direction (e.g., x-axis direction) in addition to the surface in the upper direction (z-axis direction) that is already open. Meanwhile, in the example illustrated in FIGS. 9 and 10, the opening (144o) of the groove (144) is shown as being formed only at one end (upper end in the x-axis direction) of the protective jig (140), but the location where the opening (144o) of the groove (144) is formed is not limited by the illustrated shape. For example, the opening (144o) of the groove (144) may be formed at both ends (upper end in the x-axis direction and upper end in the -x-axis direction) of the protective jig (140).

[0092] As the groove (144) is opened at one end (upper end in the x-axis direction) or both ends (upper end in the x-axis direction and upper end in the -x-axis direction) of the protective jig (140), processing to form the groove (144) on the protective jig (140) may be easier. Accordingly, the ease of manufacturing the protective jig (140) may be further improved. At the same time, since the total amount of material required to form the protective jig (140) may be reduced, the manufacturing cost of the protective jig (140) may be reduced.

[0093] FIG. 11 is a top view illustrating another example of the protective jig shown in FIG. 4. FIG. 12 is a cross-sectional view showing a cross section cut along the cutting line B-B' of FIG. 11.

[0094] Referring to FIGS. 11 and 12, the welding device (100) may include a protective member (150) that is replaceably inserted into a groove (144) of a protective jig (140).

[0095] At this time, the protective jig (140) and the protective member (150) may be formed from different materials. For example, the protective jig (140) may be formed from a ceramic material, and the protective member (150) may be formed from a metal material. Since the ceramic material is resistant to thermal deformation, it can further suppress thermal deformation of the protective jig (140). However, if a laser is repeatedly irradiated, damage may occur to the protective jig (140) made of the ceramic material. Therefore, the protective member (150) can be inserted into the groove (144) of the protective jig (140) to prevent damage to the protective jig (140).

[0096] FIG. 13 is a perspective view illustrating another example of the protective jig shown in FIG. 4. FIG. 14 is a cross-sectional view showing a cross section cut along the cutting line C-C' of FIG. 13.

[0097] Referring to FIGS. 13 and 14, the protective jig (140) may include a hollow portion (145) that forms an empty space inside the first region (141a). In this case, the hollow portion (145) may not be in communication with the outside of the protective jig (140).

[0098] In an embodiment of the present invention, since the hollow portion (145) of the protective jig (140) is formed inside the first region (141a) at a predetermined distance from each of the two sides, the two sides of the protective jig (140) where no empty space is formed may have high rigidity and low thermal deformation. Accordingly, the two sides of the protective jig (140) can suppress thermal deformation that may occur in the first region. Therefore, it is possible to suppress deformation of the protective jig (140) caused by a laser penetrating the workpiece (20).

[0099] Specifically, thermal deformation may occur centered on a local area where a laser penetrating the workpiece (20) is irradiated. For example, thermal deformation may occur in the first area (141a) of the protective jig (140). On the other hand, the two sides of the protective jig (140) are not affected by the laser, and since no empty space (hollow area; 145) is formed in the two sides of the protective jig (140), the rigidity against bending is high. Therefore, the two sides of the protective jig (140) are affected by heat, and deformation in the first area (141a), which has low rigidity against bending, can be suppressed, thereby minimizing the deformation of the protective jig (140). That is, by forming a hollow area (145) inside the first area (141a) of the protective jig (140), it is possible to minimize locally occurring thermal deformation.

[0100] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention.

[0101] [Explanation of the symbol]

[0102] 10: Secondary battery

[0103] 11: Battery cell

[0104] 20: Workpiece (electrode lead)

[0105] 100: Welding device

[0106] 110: Main Jig

[0107] 111: Guide Home

[0108] 120: Upper jig

[0109] 130: Laser generator

[0110] 140: Protective jig

[0111] 141: Main body

[0112] 142: Connecting part

[0113] 143: Through hole

[0114] 144: Homeboo

[0115] 145: Hollowboo

[0116] 150: Absence of protection

Claims

1. A main jig supporting at least a portion of the workpiece; A laser generating device that welds the above-mentioned workpiece by irradiating it with a laser; and It includes a protective jig that extends in one direction and is positioned on the opposite side of the laser generating device with respect to the workpiece, The above protective jig includes a first area corresponding to the area where the laser is irradiated on the workpiece, and a second area excluding the first area. A welding device in which the area of ​​the first cross-section of the protective jig, which is cut by a plane perpendicular to the first direction, is smaller than the area of ​​the second cross-section, which is cut by a second region.

2. In Paragraph 1, A welding device comprising a first cross section including a void space formed by being spaced apart from each of the two sides of the protective jig by a predetermined distance.

3. In Paragraph 2, A welding device comprising a protective jig that includes a groove formed by being recessed from the surface facing the workpiece in the first region to form the empty space.

4. In Paragraph 3, The above-mentioned groove is a welding device extending along the above-mentioned one direction.

5. In Paragraph 4, A welding device comprising a groove portion including an opening that is opened on one end or both ends of the protective jig with respect to the one direction.

6. In Paragraph 3, A welding device further comprising a protective member replaceably inserted into the groove of the protective jig.

7. In Paragraph 6, A welding device in which the above protective jig and the above protective member are formed of different materials.

8. In Paragraph 7, The above protective jig is formed of a ceramic material, and The above protective member is a welding device formed of a metal material.

9. In Paragraph 2, The above protective jig is a welding device comprising a hollow portion that forms the empty space within the first region.

10. In Paragraph 9, A welding device in which the above hollow portion is not in communication with the outside of the above protective jig.

11. In Paragraph 2, A welding device in which the cross-section of the above empty space is rectangular.

12. In Paragraph 11, A welding device in which, when the direction in which the laser is irradiated is called the vertical direction and the direction perpendicular thereto is called the horizontal direction, the ratio of the vertical length of the empty space to the vertical length of the protective jig is 0.43 to 0.

8.

13. In Paragraph 11, A welding device in which, when the direction in which the laser is irradiated is called the vertical direction and the direction perpendicular thereto is called the horizontal direction, the ratio of the horizontal length of the empty space to the horizontal length of the protective jig is 0.3 to 0.

6.

14. In Paragraph 1, The above protective jig comprises: a main body portion extending in the above one direction and including the above first region; and A welding device comprising a fastening part fixedly coupled to the main jig.

15. In Paragraph 14, A welding device in which the above protective jig is interchangeably coupled to the above main jig.

16. In Paragraph 14, A welding device comprising a main jig having a guide groove formed by being recessed to accommodate a part of the main body of the protective jig.

17. In Paragraph 16, A welding device in which both sides of the protective jig are supported by the guide grooves of the main jig.

18. In Paragraph 17, The above protective jig is a welding device in which the main body is inserted into the guide groove of the main jig and then fixed to the main jig through the fastening part.

19. In Paragraph 1, The above protective jig is a welding device comprising at least one of a metal material and a ceramic material.

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