Laminated capacitor welding device and production process thereof

Abstract

The laminated capacitor welding device comprises a conveying mechanism and a welding base, a laser welding head is installed at the top of the welding base, a rotating disc and a driving part are rotationally arranged in the middle of the welding base, and a laser channel is formed in the peripheral wall of the cambered surface of the rotating disc in the radial direction in a penetrating mode; a plurality of puncture seats are fixedly connected to the peripheral wall of the cambered surface of the rotating disc, a plurality of puncture needles are fixedly connected to the puncture seats, and the driving part and the laser welding head are jointly connected with a welding controller. The welding controller is configured to control the driving piece to drive the rotating disc to rotate when the conveying mechanism intermittently conveys one patch on the lead frame to the position below the rotating disc, the multiple puncture needles pierce the single-layer patch, and the protruding needles composed of part of metal gaskets and part of aluminum foil are rotationally pried up. And when the turntable rotates until the laser channel on the turntable is aligned with the laser welding head, the laser welding head is controlled to weld a plurality of stabs on the patch. The bonding strength between the aluminum foil and the metal gasket and the bonding strength between the upper-layer patch and the lower-layer patch can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of metal welding, and in particular to a laminated capacitor welding device and its production process. Background Art

[0002] The laminated solid-state capacitor is mainly composed of multiple layers of aluminum foils stacked together. During the preparation process, the negative electrodes of the aluminum foils are fixed by bonding, while the positive electrodes need to be fixed by welding. Since there are gaps between the positive ends of adjacent aluminum foils, when the number of stacked layers is large, in order to avoid the bending of the aluminum foil due to the height difference during welding, which may damage the insulating medium on the surface of the core, resulting in an increase in the leakage current of the capacitor or even failure, a conductive metal gasket is usually added to the positive end of the aluminum foil to reduce the height difference between the positive and negative electrodes, relieve the bending stress caused by the height difference between the positive and negative electrodes during the welding process, and then weld layer by layer. Usually, the thickness of the aluminum foil is 0.01 - 0.1 mm, and the thickness of the metal gasket is 0.05 - 0.2 mm.

[0003] In the related art, the Chinese patent application with the application number CN202122777270.1 proposed a welding device for processing laminated solid-state capacitors, including a welding workbench. A pressing plate for pressing the lead frame is detachably arranged at the upper end of the welding workbench. A number of laminated solid-state capacitors fixedly connected thereto are evenly distributed on the lead frame. A number of pressing blocks matching the laminated solid-state capacitors extend outward from one side of the pressing plate close to the laminated solid-state capacitors for pressing the positive ends of the laminated solid-state capacitors. A number of pressing blocks are fixedly arranged at the upper end of the welding workbench for pressing the pressing blocks towards the laminated solid-state capacitors. A welding component for welding the laminated solid-state capacitors is also arranged on one side of the welding workbench.

[0004] The above-mentioned related art has the following defects: During the process of layer-by-layer welding of the patch composed of multiple layers of metal gaskets and aluminum foils, as the number of patch layers increases, if the welding energy is too large, it may melt through the aluminum foil; if the welding energy is too small, it is likely to have problems such as poor welding effect of the patches welded later and an increase in the required welding time. And seriously, delamination may occur, resulting in a reduction in the contact area between the patches, an increase in the local current density, and a significant rise in the contact resistance, seriously affecting the ESR of the laminated capacitor. Summary of the Invention

[0005] In order to improve the problem that it is difficult to control the welding quality during layer-by-layer welding of multiple patches, which is prone to delamination and affects the ESR of the laminated capacitor, the present application provides a laminated capacitor welding device and its production process.

[0006] A laminated capacitor welding device provided in the first aspect of the present application adopts the following technical solution: A stacked capacitor welding device, comprising a workbench and a pressing plate for pressing a lead frame, the workbench is provided with a conveying mechanism for intermittently moving the lead frame, a welding seat is installed on the workbench, a laser welding head is installed on the top of the welding seat, a turntable is rotatably arranged in the middle, and a driving member for driving the turntable to rotate, and a laser channel for the welding laser of the laser welding head to pass through is opened on the outer peripheral wall of the arc surface of the turntable in the radial direction; A plurality of puncture seats are fixedly connected to the arc-surface outer peripheral wall of the turntable, and a plurality of puncture needles arranged in an array are fixedly connected to the side of the puncture seat away from the turntable. The driving member and the laser welding head are commonly connected to a welding controller; The welding controller is configured to, when the conveying mechanism intermittently conveys one of the patches on the lead frame to the bottom of the turntable, control the driving member to drive the turntable to rotate and pierce the single-layer patch with the help of multiple puncture needles and rotate to pry up the spurs composed of part of the metal gasket and the aluminum foil, until the turntable rotates to align the laser channel thereon with the laser welding head, and then control the laser welding head to weld the multiple spur parts on the patch.

[0007] Furthermore, the tip of the puncture needle is conical, so that the thorn pried up on the patch is in a barb-like structure.

[0008] Furthermore, a spiral groove is arranged on the outer peripheral wall of the tip of the puncture needle.

[0009] Furthermore, the plurality of puncture needles on two adjacent puncture seats are staggered.

[0010] Furthermore, a plurality of spinning heads are provided on the arc-surface outer peripheral wall of the turntable, and the rotational contact area between the spinning head and a single patch is not less than the area of ​​the welding area on the patch; A spinning head and an adjacent puncture seat form a group and the two are arranged on both sides of the laser channel, and the three are arranged in sequence and at intervals along the rotating direction of the turntable starting from the spinning head.

[0011] Furthermore, an electric heating element is provided in the spinning head, and the welding controller is further configured to control the turntable to rotate to the spinning head within 3 seconds after the laser welding head completes welding to perform hot pressing on the welding area on the patch.

[0012] Furthermore, an ultrasonic vibrator is embedded in the arc-surface outer wall of the turntable, and the spinning head is installed at the output end of the ultrasonic vibrator.

[0013] Furthermore, a positioning plate for pressing the patch onto the lead frame is provided on the welding seat for lifting and lowering. Two positioning plates are provided and arranged on both sides of the axis of the turntable. The free ends of the positioning plates are arc-shaped and do not invade the rotation trajectory of the puncture needle and the spinning head.

[0014] The laminated capacitor welding production process provided in the second aspect of the present application adopts the following technical solutions: A laminated capacitor welding production process, based on the above-mentioned laminated capacitor welding device, includes the following steps: S1. Fix a plurality of patches on the lead frame in sequence, fix the lead frame through the pressing plate, and then intermittently convey the lead frame by the conveying mechanism so that each patch on the lead frame passes under the turntable in sequence and stays for a set time; S2. When a single patch stays under the turntable, the welding controller controls the driving member to work, and the driving member drives the turntable to rotate so that a group of multiple piercing needles thereon rotate to pierce through the patch and pry up multiple barbs; S3. The welding controller continues to control the driving member to work, the driving member drives the turntable to continue to rotate so that the laser channel is aligned with the laser welding head, and the welding controller then controls the laser welding head to work to weld multiple barb parts on the patch; S4. After welding is completed, the turntable continues to rotate and hot-presses the welded part on the patch; S5. After hot-pressing is completed, the conveying mechanism intermittently conveys the lead frame so that the next patch stays under the turntable, and steps S2 to S4 are repeated.

[0015] Furthermore, within 3 s after welding is completed in step S4, hot-press the welded part on the patch, and the hot-pressing temperature is not less than 120 °C; when necessary, ultrasonic vibration hot-pressing is performed during hot-pressing.

[0016] In summary, the beneficial technical effects of the present application are as follows: 1. When the turntable rotates, it drives multiple piercing needles to pierce through the uppermost patch and rotate to pry up the barbs composed of part of the metal gasket and aluminum foil, causing mechanical interlocking between the metal gasket and the aluminum foil, which can significantly improve the shear strength of the two and reduce the delamination probability. At this time, the upper surface of the lower patch corresponding to the area where the barbs are formed is partially exposed; when the turntable continues to rotate, the laser emitted by the laser welding head passes through the laser channel and welds the barbs on the upper patch and the exposed area of the lower patch. After the barbs melt, the bonding strength between the aluminum foil and the metal gasket in the upper patch can be enhanced to form interlayer positioning, and the bonding strength between the upper patch and the lower patch can also be enhanced, which can avoid false soldering and poor contact, and can also achieve interlayer positioning, ensuring that the ESR of the laminated capacitor after welding multiple patches layer by layer is controlled at a low level and guaranteeing the processing quality of the laminated capacitor; 2. Integrate the piercing needle and the laser welding head on the same station through the laser channel on the turntable, enabling the laser welding head and the piercing needle to cooperate, eliminating the need for repeated positioning of the patches on the wire frame, helping to reduce processing errors, improve welding efficiency, and making the overall device structure more compact; 3. By setting the tip of the puncture needle to a conical shape, it is possible to effectively suppress the tearing of the material edges of the aluminum foil and the metal gasket when the puncture needle forms a barb during tilting, and avoid the occurrence of microcracks caused by internal stress concentration after patch welding. Moreover, the spiral groove provided on the tip of the puncture needle, on the one hand, can enhance the cutting effect on the patch, improve the smoothness of the barb edge, and further reduce the possibility of tearing of the patch material edge; on the other hand, it can ensure the forming quality of the barb when the puncture needle tilts the aluminum foil and the metal gasket, and ensure the forming consistency of multiple barbs as much as possible to ensure the flatness of patch welding. 4. By staggering the multiple puncture needles on adjacent two puncture seats, the tight binding points formed by barbs on adjacent two layers of patches can be distributed in a staggered manner on the patch plane, which can not only avoid the puncture needle from damaging the original tight binding points during subsequent welding, but also improve the distribution breadth of the tight binding points formed by barbs on the patch plane, thereby further enhancing the interlayer peeling resistance performance between adjacent two layers of patches. 5. By arranging a spinning head on the turntable and heating the spinning head, it is possible to integrate three working stations of puncture - welding - hot pressing for collaborative operation on the turntable, further improving the welding efficiency. Moreover, by hot - pressing the patch welding area within 3 s after welding with the spinning head, it is possible to achieve metallurgical - mechanical composite bonding of the patch welding area by virtue of the semi - solid state characteristics of the molten pool in the welding area, which can eliminate welding pores to a certain extent and thus improve the welding quality. Brief Description of the Drawings

[0017] Figure 1 is the overall structural schematic diagram of the embodiment of the present application; Figure 2 is the sectional structural schematic diagram of the embodiment of the present application during the puncture operation; Figure 3 is the schematic diagram of forming barbs during the puncture operation of the embodiment of the present application; Figure 4 is the structural schematic diagram of the puncture needle of the embodiment of the present application; Figure 5 is the sectional structural schematic diagram of the embodiment of the present application during the welding operation; Figure 6 is the sectional structural schematic diagram of the embodiment of the present application during the hot - pressing operation; Figure 7 is the sectional structural schematic diagram of the embodiment of the present application when an ultrasonic vibrator is provided.

[0018] Description of the Reference Numerals: 1, workbench; 21, lead frame; 22, patch; 221, barb; 3, welding seat; 31, laser welding head; 32, driving part; 4, turntable; 41, laser channel; 51. Piercing base; 52. Piercing needle; 521. Spiral groove 6. Spinning head; 61. Electric heating element; 62. Ultrasonic vibrator 71. Positioning plate; 72. Positioning frame; 73. Linear driving member Specific implementation mode

[0019] Next, it will be combined with the attached Figure 1-7 The technical solutions of this application will be described clearly and completely. Obviously, the described embodiments are part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application.

[0020] The embodiment of this application discloses a stacked capacitor welding device. Refer to Figure 1 , Figure 2 and Figure 3 , which includes a workbench 1 and a pressing plate for pressing the lead frame 21. A conveying mechanism for intermittently laterally moving the lead frame 21 is arranged on the workbench 1; among them, both the pressing plate and the conveying mechanism are conventional technical means and will not be elaborated here. A welding seat 3 is installed on the workbench 1. A laser welding head 31 is installed on the top of the welding seat 3, a turntable 4 is rotatably arranged in the middle, and a driving member 32 for driving the turntable 4 to rotate is provided. The driving member 32 can be a servo motor or a stepping motor. A laser channel 41 through which the welding laser of the laser welding head 31 can pass is radially penetrated along the outer peripheral wall of the arc surface of the turntable 4.

[0021] A plurality of piercing seats 51 are fixedly connected to the outer peripheral wall of the arc surface of the turntable 4. A plurality of piercing needles 52 arranged in an array are fixedly connected to the side of the piercing seat 51 facing away from the turntable 4. The driving member 32 and the laser welding head 31 are jointly connected to a welding controller; specifically, at least three piercing needles 52 are arranged on one piercing seat 51, and the total coverage area of the plurality of piercing needles 52 does not exceed the area of the welding area on the patch 22, but is not less than half of the area of the welding area on the patch 22. And, only one piercing seat 51 can be arranged on the turntable 4, or multiple piercing seats 51 can be arranged to improve the processing efficiency. In this embodiment, two piercing seats 51 are arranged and are circumferentially arrayed at equal intervals with respect to the axis of the turntable 4, and the two piercing seats 51 are arranged on both sides of the laser channel 41.

[0022] The welding controller is configured such that when the conveying mechanism intermittently conveys one of the patches 22 on the lead frame 21 below the turntable 4, it controls the driving member 32 to drive the turntable 4 to rotate and uses multiple piercing needles 52 to pierce through the single-layer patch 22 and rotate to pry up the spurs 221 composed of part of the metal gasket and aluminum foil until the laser channel 41 on the turntable 4 is aligned with the laser welding head 31, and then controls the laser welding head 31 to weld multiple parts of the spurs 221 on the patch 22.

[0023] The depth at which the piercing needle 52 penetrates into the patch 22 is determined according to the thickness of the single layer of the patch 22, and it is appropriate to just pierce through the single-layer patch 22 to avoid scratching the lower-layer patch 22 and affecting the service life of the piercing needle 52; moreover, the height of the spurs 221 pried up by the piercing needle 52 does not exceed the distance between two adjacent piercing needles 52 and does not exceed three times the thickness of the single layer of the patch 22. While ensuring that the holes formed by two adjacent spurs 221 are not connected, it also avoids excessive damage area to the welding area of the patch 22; furthermore, the inclination angle of the spurs 221 is preferably 15° to 45°, so as to avoid forming irregular protrusions on the surface of the patch 22 after welding when the inclination angle of the spurs 221 is too high, which affects the fitting degree between the patches 22.

[0024] Thus, during the process of layer-by-layer welding of the stacked capacitors, first, the conveying mechanism intermittently conveys one of the patches 22 on the lead frame 21 below the turntable 4. The driving member 32 drives the turntable 4 to rotate and drives multiple piercing needles 52 on the piercing seat 51 to pierce through the uppermost patch 22 and rotate to pry up the spurs 221 composed of part of the metal gasket and aluminum foil, causing mechanical interlocking between the metal gasket and the aluminum foil, which can significantly improve the shear strength of the two and reduce the delamination probability; and at this time, the upper surface of the lower-layer patch 22 corresponding to the area where the spurs 221 are formed is partially exposed.

[0025] Then the turntable 4 continues to rotate until the laser channel 41 on it is aligned with the laser welding head 31. The laser emitted by the laser welding head 31 passes through the laser channel 41 on the turntable 4 and welds the spurs 221 on the upper-layer patch 22 and the exposed area of the lower-layer patch 22. As Figure 5 shown, after the spurs 221 are melted, the bonding strength between the aluminum foil and the metal gasket in the upper-layer patch 22 can be enhanced, avoiding false soldering and poor contact, and forming an interlayer positioning between the aluminum foil and the metal gasket in the upper-layer patch 22, reducing the interlayer offset, and significantly reducing the contact resistance between the two. And when the spurs 221 are melted in the exposed area of the lower-layer patch 22, it can also enhance the bonding strength between the upper-layer patch 22 and the lower-layer patch 22, not only avoiding false soldering and poor contact, but also forming an interlayer positioning between the upper and lower layers of the patches 22, reducing the interlayer offset, and also significantly reducing the contact resistance between the two. Thus, the ESR of the stacked capacitors after layer-by-layer welding of multiple patches 22 can be controlled at a lower level, ensuring the processing quality of the stacked capacitors.

[0026] Moreover, by arranging two groups of puncture needles 52 on the turntable 4, continuous welding processing of multiple patches 22 on the lead frame 21 can be ensured, which can significantly improve the welding efficiency of the stacked capacitor; at the same time, the puncture needles 52 and the laser welding head 31 are integrated on the same workstation with the help of the laser channel 41 on the turntable 4, so that the laser welding head 31 and the puncture needles 52 can work together without repeated positioning, which helps to reduce processing errors, improve welding efficiency, and the overall device structure is also more compact.

[0027] Furthermore, in order to further ensure the forming effect of the spur 221 and reduce the probability of the aluminum foil and / or metal gasket on the patch 22 being torn and damaged, refer to Figure 4 The tip of the puncture needle 52 is conical, so that the protrusion 221 pried up on the patch 22 is in a barb-like structure; and the outer peripheral wall of the tip of the puncture needle 52 is provided with a spiral groove 521, and the groove depth of the spiral groove 521 is 0.03mm~0.06mm. The specific setting should be mainly based on matching the thickness of the aluminum foil and the metal gasket.

[0028] Therefore, by setting the tip of the puncture needle 52 to be conical, the tearing of the edges of the aluminum foil and the metal gasket when the puncture needle 52 is lifted up to form the spur 221 can be effectively suppressed, thereby avoiding the occurrence of microcracks caused by internal stress concentration after the patch 22 is welded; moreover, the spiral groove 521 set on the tip of the puncture needle 52, on the one hand, can enhance the cutting effect on the patch 22, improve the smoothness of the edge of the spur 221, and further reduce the possibility of tearing of the edge of the patch 22 material; on the other hand, it can ensure the molding quality of the spur 221 when the puncture needle 52 lifts the aluminum foil and the metal gasket, and ensure the molding consistency of multiple spurs 221 as much as possible to ensure the flatness of the welding of the patch 22.

[0029] In addition, the multiple puncture needles 52 on two adjacent puncture seats 51 are staggered, for example, the arrangement shapes are different or the arrangement shapes are the same but the positions are different, so that when the multiple puncture needles 52 on the two puncture seats 51 respectively form two groups of multiple spurs 221 on the patch 22, the relative positions of the two groups of multiple spurs 221 are staggered with each other. If the same stacked capacitor is continuously welded layer by layer, the tight bonding points formed by the spurs 221 on the two adjacent layers of patches 22 can be staggered and distributed on the plane of the patch 22, which can avoid the puncture needles 52 from damaging the original tight bonding points during subsequent welding, and increase the distribution breadth of the tight bonding points formed by the spurs 221 on the plane of the patch 22, thereby further enhancing the anti-interlayer peeling performance between the two adjacent layers of patches 22. If multiple patches 22 on the lead frame 21 are welded continuously, the patches 22 on the lead frame 21 can be staggered when welding the second layer of patches 22, so that the adjacent layer welding on any patch 22 can maintain the staggered state of the protrusions 221, thereby achieving the above-mentioned effect.

[0030] Further, to improve the flatness of the surface of the patch 22 after laser welding, referring to Figure 1 and Figure 2 , a number of spinning heads 6 are further provided on the outer peripheral wall of the arc surface of the turntable 4. The rotational contact area of the spinning head 6 with a single patch 22 is not less than the area of the welding region on the patch 22. One spinning head 6 and an adjacent puncture seat 51 form a group and are arranged on both sides of the laser channel 41. And the three are sequentially arranged at intervals along the rotation direction of the turntable 4 starting from the spinning head 6. In this embodiment, two puncture seats 51 are provided, two spinning heads 6 are also provided, and two corresponding laser channel 41 outlet ends / import ends are also provided. These six are circumferentially arrayed around the axis of the turntable 4, that is, the rotation angle of the turntable 4 for each operation is the same, both being 60°, which is convenient for the welding controller to control and cooperate with the conveying mechanism.

[0031] Moreover, for the spinning head 6, the head end on the side along the rotation direction of the turntable 4 should have a slightly convex curved surface so that it fits the surface of the patch 22 during the rotation and pressurization process to ensure the consistency of pressurization. Moreover, in different embodiments, the spinning head 6 can be controlled to dynamically spin-press the patch 22, or the spinning head 6 can be controlled to maintain pressure for a certain period of time after spinning-pressing the patch 22. If pressure is to be maintained, the head end of the spinning head 6 should not only have a slightly convex curved surface but also a continuous flat surface to ensure the flatness of pressure maintenance.

[0032] Further, in different embodiments, the spinning head 6 can directly perform cold pressing on the welded patch 22, or hot pressing. If it is hot pressing, an electric heating element 61 is further provided in the spinning head 6, as Figure 2 shown, and the welding controller is further configured to control the turntable 4 to rotate to the spinning head 6 to perform hot pressing on the welding region on the patch 22 within 3 s after the laser welding head 31 finishes welding.

[0033] Moreover, those skilled in the art should know that the above different technical solutions can be freely combined in different embodiments without creative labor.

[0034] Thus, taking hot pressing as an example, when welding is completed, the turntable 4 rotates to the spinning head 6 to perform hot pressing on the welding region on the patch 22 within 3 s. At this time, the molten pool on the patch 22 still retains a certain high temperature, and the metallurgical-mechanical composite bonding of the welding region of the patch 22 can be realized by means of the semi-solid state characteristics of the molten pool, which can eliminate welding pores to a certain extent and thus improve the welding quality, as Figure 6 shown; moreover, if pressure is maintained, this advantage can be further expanded. And since the rotational contact area of the spinning head 6 on the patch 22 is not less than the area of the welding region on the patch 22, the aluminum foil wrinkles caused by local overload during the spinning process can be avoided, and the flatness of the surface of the welded patch 22 can be ensured.

[0035] In another feasible embodiment, to further promote the hot pressing and flattening effects of the spinning head 6 on the patch 22, an ultrasonic vibrator 62 can also be embedded and installed on the outer wall of the arc surface of the turntable 4. As Figure 7 shown, the spinning head 6 is installed at the output end of the ultrasonic vibrator 62; the amplitude of the high-frequency micro-vibration output by the ultrasonic vibrator 62 is 0.01 - 0.03 mm, and before the spinning head 6 moves away from the patch 22, the ultrasonic vibrator 62 should be controlled to reduce the amplitude or stop outputting vibration to avoid causing the structure of the welding area of the patch 22 to become loose.

[0036] Thus, while the spinning head 6 performs hot pressing, high-frequency micro-vibration is introduced, which can further reduce the porosity of the welding area on the patch 22, improve the welding quality, and also further improve the flatness of the welding area on the patch 22 and the uniformity of the curing and forming of the welding layer.

[0037] In addition, it should be particularly noted that in order to prevent the drill plate from driving the puncture needle 52 and the spinning head 6 to cause relative displacement of the aluminum foil and the metal gasket when operating on the patch 22, referring to Figure 1 and Figure 2 , a positioning plate 71 for pressing the patch 22 onto the lead frame 21 is arranged to move up and down on the welding seat 3. There are two positioning plates 71, which are arranged on both sides of the axis of the turntable 4. The free ends of the positioning plates 71 are arc-shaped and do not intrude into the rotation trajectories of the puncture needle 52 and the spinning head 6; specifically, a linear driving member 73, such as a cylinder or an electric push rod, is installed on the welding seat 3. The two positioning plates 71 are installed at the output end of the linear driving member 73 through a positioning frame 72, and the free ends of the two positioning plates 71 are pressed against the edge parts of the patch 22.

[0038] Thus, when the conveying mechanism conveys a patch 22 on the lead frame 21 to the lower part of the turntable 4, the linear driving member 73 drives the two positioning plates 71 to move downwards to press the two opposite side edges of the patch 22 along the rotation direction of the turntable 4. Then, when the puncture needle 52 rotates and pricks up the protrusion 221 and the spinning head 6 rotates and applies pressure, the patch 22 can remain stable on the lead frame 21, ensuring the smooth progress of the puncture operation and the hot pressing operation.

[0039] The embodiment of the present application discloses a laminated capacitor welding production process, based on the above-mentioned laminated capacitor welding device, referring to Figure 1 , Figure 2 and Figure 3 , which includes the following steps: S1. Fix a plurality of patches 22 on the lead frame 21 in sequence, fix the lead frame 21 through a pressing plate, and then intermittently convey the lead frame 21 by a conveying mechanism so that each patch 22 on the lead frame 21 passes under the turntable 4 in sequence and stays for a set time.

[0040] S2. When a single patch 22 stays below the turntable 4, first, two positioning plates 71 press and fix both sides of the patch 22, and then the welding controller controls the driving member 32 to work. The driving member 32 drives the turntable 4 to rotate so that a group of multiple piercing needles 52 thereon rotate to pierce through the patch 22 and pry up multiple protrusions 221, as Figure 2 and Figure 3 shown.

[0041] S3. The welding controller continues to control the driving member 32 to work. The driving member 32 drives the turntable 4 to continue rotating so that the laser channel 41 is aligned with the laser welding head 31. Then the welding controller controls the laser welding head 31 to work to weld the parts of multiple protrusions 221 on the patch 22, as Figure 5 shown.

[0042] S4. After welding is completed, the turntable 4 continues to rotate and hot-presses the welded part on the patch 22, and the welded part on the patch 22 is hot-pressed within 3 s after welding is completed. The hot-pressing temperature is not less than 120 °C; when necessary, ultrasonic vibration hot-pressing is performed during hot-pressing, as Figure 6 and Figure 7 shown.

[0043] S5. After hot-pressing is completed, the two positioning plates 71 move away from the patch 22, and the conveying mechanism intermittently conveys the lead frame 21 so that the next patch 22 stays below the turntable 4, and steps S2 to S4 are repeated.

[0044] Unless otherwise defined, the technical terms or scientific terms used in this application shall have the ordinary meanings understood by those of ordinary skill in the field to which this application belongs. The "first", "second", "third" and similar terms used in the specification and claims of this application do not denote any order, quantity or importance, but are only used to distinguish different components. The similar terms such as "a" or "one" do not denote a quantity limitation, but mean that there is at least one. The similar terms such as "comprising" or "including" mean that the elements or objects appearing before "comprising" or "including" cover the elements or objects listed after "comprising" or "including" and their equivalents, and do not exclude other elements or objects. The terms such as "upper", "lower", "left", "right" are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationships may also change accordingly.

[0045] The above are all preferred embodiments of this application, and the protection scope of this application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape and principle of this application shall be covered within the protection scope of this application.

Claims

1. A stacked capacitor welding device, comprising a workbench (1) and a pressing plate for pressing a lead frame (21), characterized in that, A conveying mechanism for intermittently traversing a lead frame (21) is provided on the workbench (1). A welding seat (3) is installed on the workbench (1). A laser welding head (31) is installed on the top of the welding seat (3), a turntable (4) is rotatably arranged in the middle, and a driving member (32) for driving the turntable (4) to rotate. A laser channel (41) through which the welding laser of the laser welding head (31) can pass is radially penetrated through the outer peripheral wall of the arc surface of the turntable (4). A plurality of puncture seats (51) are fixedly connected to the outer peripheral wall of the arc surface of the turntable (4). A plurality of puncture needles (52) arranged in an array are fixedly connected to the side of the puncture seat (51) facing away from the turntable (4). The driving member (32) and the laser welding head (31) are jointly connected to a welding controller. The welding controller is configured such that when the conveying mechanism intermittently conveys one of the patches (22) on the lead frame (21) below the turntable (4), it controls the driving member (32) to drive the turntable (4) to rotate and uses the plurality of puncture needles (52) to pierce through the single-layer patch (22) and rotate to pry up the spikes (221) composed of part of the metal gasket and aluminum foil until the laser channel (41) on the turntable (4) is aligned with the laser welding head (31), and then controls the laser welding head (31) to weld the parts of the plurality of spikes (221) on the patch (22).

2. The stacked capacitor welding device according to claim 1, characterized in that, The tip of the puncture needle (52) is conical so that the spikes (221) pried up on the patch (22) have a barbed structure.

3. The stacked capacitor welding device according to claim 2, characterized in that, A spiral groove (521) is provided on the outer peripheral wall of the tip of the puncture needle (52).

4. The stacked capacitor welding device according to claim 1, characterized in that, The plurality of puncture needles (52) on adjacent two puncture seats (51) are arranged in a staggered manner.

5. The stacked capacitor welding device according to any one of claims 1-4, characterized in that, A plurality of spinning heads (6) are further provided on the outer peripheral wall of the arc surface of the turntable (4). The rotational contact area of the spinning head (6) with a single patch (22) is not less than the welding area of the patch (22). One spinning head (6) and an adjacent puncture seat (51) form a group and are arranged on both sides of the laser channel (41), and the three are sequentially spaced along the rotation direction of the turntable (4) starting from the spinning head (6).

6. The stacked capacitor welding device according to claim 5, wherein, An electric heating element (61) is provided in the spinning head (6). The welding controller is further configured to control the turntable (4) to rotate to the spinning head (6) to thermally press the welding area on the patch (22) within 3 s after the laser welding head (31) finishes welding.

7. The stacked capacitor welding device according to claim 6, characterized in that, An ultrasonic vibrator (62) is embedded and installed on the outer wall of the arc surface of the turntable (4). The spinning head (6) is installed at the output end of the ultrasonic vibrator (62).

8. The stacked capacitor welding device according to claim 5, characterized in that, A positioning plate (71) for pressing the patch (22) on the lead frame (21) is arranged on the welding seat (3) in a lifting manner. There are two positioning plates (71) and they are arranged on both sides of the axis of the turntable (4). The free end of the positioning plate (71) is arc-shaped and does not intrude into the rotation trajectories of the puncture needles (52) and the spinning heads (6).

9. A laminated capacitor welding production process, based on the laminated capacitor welding device according to any one of claims 1-8, characterized in that, Including the following steps: S1. Fix multiple patches (22) on the lead frame (21) sequentially one by one, fix the lead frame (21) through the pressing plate, and then intermittently convey the lead frame (21) by the conveying mechanism so that each patch (22) on the lead frame (21) passes under the turntable (4) in turn and stays for a set time; S2. When a single patch (22) stays under the turntable (4), the welding controller controls the driving member (32) to work, and the driving member (32) drives the turntable (4) to rotate so that a group of multiple piercing needles (52) on it rotate to pierce the patch (22) and pry up multiple spikes (221); S3. The welding controller continues to control the driving member (32) to work, the driving member (32) drives the turntable (4) to continue to rotate so that the laser channel (41) is aligned with the laser welding head (31), and the welding controller then controls the laser welding head (31) to work to weld multiple spike (221) parts on the patch (22); S4. After welding is completed, the turntable (4) continues to rotate and hot-presses the welded part on the patch (22); S5. After hot-pressing is completed, the conveying mechanism intermittently conveys the lead frame (21) so that the next patch (22) stays under the turntable (4), and steps S2 to S4 are repeated.

10. The laminated capacitor welding production process according to claim 9, characterized in that, In step S4, the welded part on the patch (22) is hot-pressed within 3 s after welding is completed, and the hot-pressing temperature is not less than 120 °C; when necessary, ultrasonic vibration hot-pressing is performed during hot-pressing.

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