Stacked capacitor welding apparatus and production process thereof

Abstract

This application relates to a multilayer capacitor welding apparatus and its manufacturing process, comprising a conveying mechanism and a welding stand. A laser welding head is mounted on the top of the welding stand, a turntable and a driving component are rotatably mounted in the middle, and a laser channel is radially penetrated on the outer peripheral wall of the turntable's arc surface. Several piercing seats are fixedly connected to the outer peripheral wall of the turntable's arc surface, and multiple piercing needles are fixedly connected to the piercing seats. The driving component and the laser welding head are jointly connected to a welding controller. The welding controller is configured such that when the conveying mechanism intermittently conveys one of the patches on the lead frame to below the turntable, it controls the driving component to rotate the turntable and, with the help of multiple piercing needles, pierce the single-layer patch and rotate to pry up the protrusions composed of partial metal pads and aluminum foil, until the turntable rotates to the point where the laser channel on it aligns with the laser welding head. Then, it controls the laser welding head to weld the multiple protrusions on the patch. This application can improve the bonding strength between aluminum foil and metal pads, as well as between upper and lower patch components.

Description

Technical Field

[0001] This application relates to the technical field of metal welding, and in particular to a welding apparatus for multilayer capacitors and its manufacturing process. Background Technology

[0002] Multilayer solid-state capacitors are mainly composed of multiple layers of aluminum foil. During the manufacturing process, the negative terminals of each aluminum foil are fixed by adhesive bonding, while the positive terminals are fixed by welding. Because there are gaps between the positive terminals of adjacent aluminum foils, when there are many layers, to prevent the height difference during welding from causing the aluminum foil to bend and damage the insulating dielectric on the core surface, resulting in increased leakage current or even capacitor failure, conductive metal spacers are usually added to the positive terminals of the aluminum foils to reduce the height difference between the positive and negative terminals. This alleviates the bending stress caused by the height difference during welding, and then the layers are welded one by one. Typically, the thickness of the aluminum foil is 0.01–0.1 mm, and the thickness of the metal spacer is 0.05–0.2 mm.

[0003] In the related technology, Chinese patent application CN202122777270.1 discloses a welding device for processing multilayer solid capacitors, including a welding worktable. The upper end of the welding worktable is detachably provided with a pressure plate for pressing the lead frame. Several multilayer solid capacitors are evenly distributed on the lead frame and fixedly connected thereto. Several pressure blocks that match the multilayer solid capacitors extend outward from the side of the pressure plate near the multilayer solid capacitors for pressing the positive terminal of the multilayer solid capacitors. Several pressure blocks that press the pressure blocks against the multilayer solid capacitors are also fixedly provided on the upper end of the welding worktable. A welding assembly for welding multilayer solid capacitors is also provided on one side of the welding worktable.

[0004] The aforementioned technologies have the following drawbacks: during the layer-by-layer soldering of patches composed of multilayer metal pads and aluminum foil, as the number of patch layers increases, if the soldering energy is too high, it may melt through the aluminum foil; if the soldering energy is too low, it may easily lead to poor soldering effect of the later patches and increased soldering time. In severe cases, delamination may occur, resulting in a reduction in the contact area between the patches, leading to an increase in local current density and a significant increase in contact resistance, which seriously affects the ESR of the multilayer capacitor. Summary of the Invention

[0005] To address the issue of difficulty in controlling welding quality and the resulting delamination during the layer-by-layer soldering of multilayer chips, which can affect the ESR of multilayer capacitors, this application provides a multilayer capacitor soldering apparatus and its manufacturing process.

[0006] The first aspect of this application provides a multilayer capacitor welding device with the following technical solution:

[0007] A multilayer capacitor welding device includes a worktable and a pressure plate for pressing the lead frame. The worktable is provided with a conveying mechanism for intermittently moving the lead frame. A welding seat is installed on the worktable. A laser welding head is installed on the top of the welding seat, and a turntable is rotatably arranged in the middle and a driving component for driving the turntable to rotate. A laser channel is radially opened on the outer peripheral wall of the arc surface of the turntable so that the welding laser of the laser welding head can pass through.

[0008] Several puncture seats are fixedly connected to the outer peripheral wall of the turntable arc surface. Multiple puncture needles arranged in an array are fixedly connected to the side of the puncture seats away from the turntable. The drive unit and the laser welding head are connected to a welding controller.

[0009] The welding controller is configured such that when the conveying mechanism intermittently conveys one of the patches on the lead frame to the area below the turntable, the control drive drives the turntable to rotate and uses multiple piercing needles to pierce the single-layer patch and rotate to pry up the protrusions composed of partial metal pads and aluminum foil, until the turntable rotates to the point where the laser channel on it is aligned with the laser welding head, and then controls the laser welding head to weld the multiple protrusions on the patch.

[0010] Furthermore, the tip of the puncture needle is conical, so that the protrusions it pries out on the patch have a barbed structure.

[0011] Furthermore, the outer peripheral wall of the tip of the puncture needle is provided with a spiral groove.

[0012] Furthermore, the multiple puncture needles on two adjacent puncture seats are staggered.

[0013] Furthermore, a number of spinning heads are provided on the outer peripheral wall of the turntable arc surface, and the rotational contact area between the spinning head and a single patch is not less than the welding area on the patch.

[0014] A spinning head and an adjacent puncture seat form a group, with the two positioned on opposite sides of the laser channel, and the three are arranged sequentially at intervals along the rotation direction of the turntable, starting from the spinning head.

[0015] Furthermore, the spinning head is equipped with an electric heating element, and the welding controller is also configured to control the turntable to rotate to the spinning head to perform hot pressing on the welding area on the patch within 3 seconds after the laser welding head is completed.

[0016] Furthermore, an ultrasonic vibrator is embedded in the outer wall of the turntable's arc surface, and the spinning head is installed at the output end of the ultrasonic vibrator.

[0017] Furthermore, the welding base is equipped with a positioning plate for pressing the patch onto the lead frame. There are two positioning plates arranged on both sides of the turntable axis. The free end of the positioning plate is arc-shaped and does not intrude into the rotation trajectory of the puncture needle and the spin head.

[0018] The second aspect of this application provides a multilayer capacitor welding manufacturing process using the following technical solution:

[0019] A multilayer capacitor welding process, based on the aforementioned multilayer capacitor welding apparatus, includes the following steps:

[0020] S1. Fix multiple patches sequentially onto the lead frame, and fix the lead frame with the pressure plate. Then, use the conveying mechanism to intermittently convey the lead frame so that each patch on the lead frame passes under the turntable sequentially and stays for a set time.

[0021] S2. When a single patch is positioned below the turntable, the welding controller controls the drive unit to operate, which drives the turntable to rotate so that a group of multiple puncture needles on it rotate to puncture the patch and pry up multiple protrusions;

[0022] S3. The welding controller continues to control the drive unit to work, and the drive unit drives the turntable to continue rotating so that the laser channel is aligned with the laser welding head. The welding controller then controls the laser welding head to work to weld multiple protrusions on the patch.

[0023] S4. After welding is completed, the turntable continues to rotate and hot-presses the welded parts on the patch;

[0024] S5. After hot pressing is completed, the conveying mechanism intermittently conveys the lead frame so that the next patch stays below the turntable, and repeats steps S2 to S4.

[0025] Furthermore, in step S4, the welded portion on the patch is hot-pressed within 3 seconds after welding is completed, and the hot-pressing temperature is not less than 120°C; if necessary, ultrasonic vibration hot-pressing is performed during hot pressing.

[0026] In summary, the beneficial technical effects of this application are as follows:

[0027] 1. As the turntable rotates, multiple piercing needles pierce the top layer of the patch and rotate it to lift the spikes composed of a portion of metal pads and aluminum foil. This mechanically interlocks the metal pads and aluminum foil, significantly improving their shear strength and reducing the probability of delamination. At this time, the upper surface of the lower patch, corresponding to the area where the spikes are formed, is partially exposed. As the turntable continues to rotate, the laser emitted from the laser welding head passes through the laser channel and welds the spikes on the upper patch and the exposed area of ​​the lower patch. After the spikes melt, the bonding strength between the aluminum foil and metal pads in the upper patch is strengthened, forming interlayer positioning. It also strengthens the bonding strength between the upper and lower patches, avoiding poor soldering and contact. It also achieves interlayer positioning, ensuring that the ESR of the multilayer capacitor is controlled at a low level after welding the multilayer patches layer by layer, thus guaranteeing the processing quality of the multilayer capacitor.

[0028] 2. By integrating the puncture needle and the laser welding head on the same station via the laser channel on the turntable, the laser welding head and the puncture needle can work together, eliminating the need for repeated positioning of the patch on the wiring frame. This helps to reduce processing errors, improve welding efficiency, and the overall device structure is also more compact.

[0029] 3. By setting the tip of the puncture needle to a conical shape, the tearing of the aluminum foil and metal gasket material edges when the puncture needle is raised to form a burr can be effectively suppressed, avoiding micro-cracks caused by internal stress concentration after patch welding. Moreover, the spiral groove set on the tip of the puncture needle can, on the one hand, enhance the cutting effect on the patch and improve the smoothness of the burr edge, further reducing the possibility of patch material edge tearing; on the other hand, it can ensure the forming quality of the burr when the puncture needle raises the aluminum foil and metal gasket, and ensure the consistency of multiple burr forming as much as possible, so as to ensure the flatness of patch welding.

[0030] 4. By staggering the multiple puncture needles on two adjacent puncture seats, the tight bonding points formed by the punctures on the two adjacent layers of the patch can be distributed in a staggered manner on the patch plane. This can not only avoid the puncture needles damaging the original tight bonding points during subsequent soldering, but also increase the distribution of the tight bonding points formed by the punctures on the patch plane, thereby further enhancing the anti-delamination performance between the two adjacent layers of the patch.

[0031] 5. By setting a spinning head on the turntable and heating the spinning head, the three-station collaborative operation of piercing-welding-hot pressing can be integrated on the turntable, further improving welding efficiency; moreover, by using the spinning head to hot press the patch welding area within 3 seconds after welding, the metallurgical-mechanical composite bonding of the patch welding area can be achieved by taking advantage of the semi-solid characteristics of the molten pool in the welding area, which can eliminate welding porosity to a certain extent, thereby improving welding quality. Attached Figure Description

[0032] Figure 1This is a schematic diagram of the overall structure of an embodiment of this application;

[0033] Figure 2 This is a cross-sectional view of an embodiment of this application during a puncture operation;

[0034] Figure 3 This is a schematic diagram illustrating the formation of a protrusion during a puncture operation according to an embodiment of this application;

[0035] Figure 4 This is a schematic diagram of the puncture needle according to an embodiment of this application;

[0036] Figure 5 This is a cross-sectional structural diagram of an embodiment of this application during welding operations;

[0037] Figure 6 This is a cross-sectional structural diagram of an embodiment of this application during hot pressing;

[0038] Figure 7 This is a cross-sectional structural diagram of an embodiment of this application with an ultrasonic vibrator.

[0039] Explanation of reference numerals in the attached figures:

[0040] 1. Workbench;

[0041] 21. Leadframe; 22. Patch; 221. Spike;

[0042] 3. Welding base; 31. Laser welding head; 32. Driving component;

[0043] 4. Turntable; 41. Laser channel;

[0044] 51. Puncture seat; 52. Puncture needle; 521. Spiral groove;

[0045] 6. Spinning head; 61. Electric heating element; 62. Ultrasonic vibrator;

[0046] 71. Positioning plate; 72. Positioning frame; 73. Linear drive component. Detailed Implementation

[0047] The following will be combined with the appendix Figure 1-7 The technical solutions of this application have been clearly and completely described. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0048] This application discloses a multilayer capacitor welding apparatus. (Refer to...) Figure 1 , Figure 2 and Figure 3It includes a worktable 1 and a pressure plate for pressing the lead frame 21. The worktable 1 is equipped with a conveying mechanism for intermittently moving the lead frame 21. The pressure plate and the conveying mechanism are conventional technologies and will not be described in detail here. A welding seat 3 is installed on the worktable 1. A laser welding head 31 is installed on the top of the welding seat 3, and a turntable 4 is rotatably arranged in the middle. A driving component 32 for driving the turntable 4 to rotate is also provided. The driving component 32 can be a servo motor or a stepper motor. A laser channel 41 is radially opened on the outer peripheral wall of the arc surface of the turntable 4 so that the welding laser of the laser welding head 31 can pass through.

[0049] Several puncture seats 51 are fixedly connected to the outer peripheral wall of the arc surface of the turntable 4. Multiple puncture needles 52 arranged in an array are fixedly connected to the side of each puncture seat 51 opposite to the turntable 4. The drive unit 32 and the laser welding head 31 are jointly connected to a welding controller. Specifically, at least three puncture needles 52 are provided on each puncture seat 51, and the total coverage area of ​​the multiple puncture needles 52 does not exceed the area of ​​the welding area on the patch 22, but is also not less than half the area of ​​the welding area on the patch 22. Furthermore, the turntable 4 can have only one puncture seat 51, or multiple puncture seats 51 can be provided to improve processing efficiency. In this embodiment, two puncture seats 51 are provided and are arranged in an equally spaced circular array around the axis of the turntable 4, with the two puncture seats 51 positioned on either side of the laser channel 41.

[0050] The welding controller is configured such that when the conveying mechanism intermittently conveys one of the patches 22 on the lead frame 21 to the bottom of the turntable 4, the control drive 32 drives the turntable 4 to rotate and pierces the single-layer patch 22 with the help of multiple piercing needles 52 and rotates to pry up the protrusions 221 composed of partial metal pads and aluminum foil, until the turntable 4 rotates to the point where the laser channel 41 on it is aligned with the laser welding head 31, and then controls the laser welding head 31 to weld the multiple protrusions 221 on the patch 22.

[0051] The depth to which the puncture needle 52 penetrates the patch 22 is determined by the thickness of a single layer of patch 22, ideally just piercing through the single layer of patch 22, to avoid scratching the lower layer of patch 22 and affecting the service life of the puncture needle 52; furthermore, the height of the protrusion 221 of the puncture needle 52 does not exceed the distance between two adjacent puncture needles 52, and does not exceed three times the thickness of a single layer of patch 22, ensuring that the holes formed by two adjacent protrusions 221 are not connected, and also avoiding excessive damage to the welding area of ​​patch 22; moreover, the tilt angle of the protrusion 221 is preferably 15° to 45°, to avoid irregular protrusions forming on the surface of patch 22 after welding when the tilt angle of the protrusion 221 is too high, which would affect the adhesion between patches 22.

[0052] Therefore, during the layer-by-layer welding process of the multilayer capacitor, the conveying mechanism first intermittently conveys one of the patches 22 on the lead frame 21 to the bottom of the turntable 4. The drive unit 32 drives the turntable 4 to rotate and drives multiple piercing needles 52 on the piercing seat 51 to pierce the top patch 22 and rotate it to lift up the protrusion 221 composed of part of the metal pad and aluminum foil. This makes the metal pad and aluminum foil mechanically interlocked, which can significantly improve their shear strength and reduce the probability of delamination. At this time, the upper surface of the lower patch 22 is partially exposed in the area corresponding to the formation of the protrusion 221.

[0053] Then, the turntable 4 continues to rotate until its laser channel 41 aligns with the laser welding head 31. The laser emitted from the laser welding head 31 passes through the laser channel 41 on the turntable 4 and welds the protrusions 221 on the upper patch 22 and the exposed area of ​​the lower patch 22, such as... Figure 5 As shown, after the spike 221 melts, it can strengthen the bonding strength between the aluminum foil and the metal pad in the upper patch 22, avoiding poor soldering and contact, and forming interlayer positioning between the aluminum foil and the metal pad in the upper patch 22, reducing interlayer offset and significantly reducing the contact resistance between them. Furthermore, when the spike 221 melts in the exposed area of ​​the lower patch 22, it can also strengthen the bonding strength between the upper and lower patches 22, not only avoiding poor soldering and contact, but also forming interlayer positioning between the upper and lower patches 22, reducing interlayer offset, and significantly reducing the contact resistance between them. Therefore, the ESR of the multilayer capacitor after the multilayer patches 22 are soldered layer by layer can be controlled at a low level, ensuring the processing quality of the multilayer capacitor.

[0054] Moreover, by setting two sets 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 multilayer capacitor. At the same time, by integrating the puncture needles 52 and the laser welding head 31 on the same station through the laser channel 41 on the turntable 4, 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.

[0055] Furthermore, to further ensure the molding effect of the spikes 221 and reduce the probability of tearing damage to the aluminum foil and / or metal gaskets on the patch 22, refer to Figure 4 The tip of the puncture needle 52 is conical, so that the protrusion 221 that it pries up on the patch 22 has a barbed structure; and the outer peripheral wall of the tip of the puncture needle 52 is provided with a spiral groove 521, the depth of which is 0.03mm to 0.06mm. The specific setting should be adapted to the thickness of the aluminum foil and the metal gasket.

[0056] Therefore, by setting the tip of the puncture needle 52 to a conical shape, the tearing of the material edges of the aluminum foil and metal pad when the puncture needle 52 is raised to form the protrusion 221 can be effectively suppressed, avoiding the occurrence of micro-cracks caused by internal stress concentration after the patch 22 is welded. Moreover, the spiral groove 521 provided on the tip of the puncture needle 52 can, on the one hand, enhance the cutting effect on the patch 22, improve the smoothness of the protrusion 221 edge, and further reduce the possibility of tearing of the patch 22 material edge; on the other hand, it can ensure the forming quality of the protrusion 221 when the puncture needle 52 raises the aluminum foil and metal pad, and ensure the consistency of the forming of multiple protrusions 221 as much as possible, so as to ensure the flatness of the patch 22 welding.

[0057] In addition, the multiple puncture needles 52 on two adjacent puncture seats 51 are staggered, for example, with different arrangement shapes or the same arrangement shape but different positions. When the multiple puncture needles 52 on the two puncture seats 51 form two sets of multiple protrusions 221 on the patch 22, the relative positions of the two sets of multiple protrusions 221 are staggered. If the same stacked capacitor is continuously soldered layer by layer, the tight bonding points formed by the protrusions 221 on the adjacent two layers of patch 22 can be staggered and distributed on the plane of patch 22. This can not only avoid the puncture needles 52 from damaging the original tight bonding points during subsequent soldering, but also increase the distribution of the tight bonding points formed by the protrusions 221 on the plane of patch 22, thereby further strengthening the anti-delamination performance between the adjacent two layers of patch 22. If multiple patches 22 on the lead frame 21 are continuously soldered, the positions of the patches 22 on the lead frame 21 can be staggered when soldering the second layer of patches 22, so that the adjacent layer soldering on any patch 22 can maintain the staggered state of the protrusions 221, thereby achieving the above effect.

[0058] Furthermore, to improve the flatness of the surface of patch 22 after laser welding, refer to Figure 1 and Figure 2 Several spinning heads 6 are also provided on the outer peripheral wall of the arc surface of the turntable 4. The rotational contact area between the spinning head 6 and a single patch 22 is not less than the welding area on the patch 22. A spinning head 6 and an adjacent puncture seat 51 form a group, and the two are arranged on both sides of the laser channel 41. The three are arranged sequentially and at intervals along the rotation direction of the turntable 4 starting from the spinning head 6. In this embodiment, there are two puncture seats 51, two spinning heads 6, and two correspondingly arranged at the exit / inlet end of the laser channel 41. These six are arranged in a circular array around the axis of the turntable 4, that is, the rotation angle of the turntable 4 is the same for each operation, which is 60°, which facilitates the control of the welding controller and coordination with the conveying mechanism.

[0059] Furthermore, the end of the spinning head 6 facing the rotation direction of the turntable 4 should have a slightly convex curved surface to ensure it adheres to the surface of the patch 22 during rotational pressing, thus ensuring consistent pressure application. In different embodiments, the spinning head 6 can be controlled to dynamically spin the patch 22, or it can be controlled to maintain pressure for a certain period after spinning the patch 22. If pressure maintenance is required, the end of the spinning head 6 should not only have a slightly convex curved surface but also a continuous flat surface to ensure even pressure maintenance.

[0060] Furthermore, in different embodiments, the spinning head 6 can directly cold press the welded patch 22, or it can hot press it. If it is hot pressing, an electric heating element 61 is also provided in the spinning head 6, such as... Figure 2 As shown, the welding controller is also configured to control the turntable 4 to rotate to the spinning head 6 to perform hot pressing on the welding area on the patch 22 within 3 seconds after the laser welding head 31 completes the welding.

[0061] Moreover, those skilled in the art should know that the above-mentioned different technical solutions can be freely combined in different embodiments without requiring creative effort.

[0062] Therefore, taking hot pressing as an example, after welding is completed, the turntable 4 rotates to the spinning head 6 within 3 seconds to hot press the welding area on the patch 22. At this time, the molten pool on the patch 22 still retains a certain high temperature. The semi-solid characteristics of the molten pool can be used to achieve a metallurgical-mechanical composite bond in the welding area of ​​the patch 22, which can eliminate welding porosity to a certain extent and thus improve the welding quality. Figure 6 As shown; moreover, if pressure holding is used, this advantage can be further amplified. And since the rotational contact area of ​​the spinning head 6 on the patch 22 is not less than the welding area on the patch 22, aluminum foil wrinkles caused by local overload during spinning can be avoided, ensuring the flatness of the patch 22 surface after welding.

[0063] In another feasible embodiment, to further promote the hot pressing and flattening effect of the spinning head 6 on the patch 22, an ultrasonic vibrator 62 can also be embedded in the outer wall of the arc surface of the turntable 4, such as... Figure 7 As shown, the spinning head 6 is installed at the output end of the ultrasonic vibrator 62; the high-frequency micro-vibration amplitude output by the ultrasonic vibrator 62 is 0.01 to 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 the output vibration to avoid causing the structure of the soldering area of ​​the patch 22 to loosen.

[0064] Therefore, by using the spinning head 6 to perform hot pressing, high-frequency micro-vibration is also 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 weld layer curing.

[0065] Additionally, it should be noted that, in order to prevent relative displacement of the aluminum foil and metal gasket when the drill bit drives the puncture needle 52 and the spinning head 6 to work on the patch 22, refer to... Figure 1 and Figure 2 A positioning plate 71 for pressing the patch 22 onto the lead frame 21 is provided on the welding base 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 trajectory of the puncture needle 52 and the spin head 6. Specifically, a linear drive 73, such as a cylinder or an electric push rod, is installed on the welding base 3. The two positioning plates 71 are installed on the output end of the linear drive 73 through the positioning frame 72, and the free ends of the two positioning plates 71 are pressed against the edge of the patch 22.

[0066] Thus, when the conveying mechanism transports a patch 22 on the lead frame 21 to below the turntable 4, the linear drive 73 drives the two positioning plates 71 to move down, so as 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 raises 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.

[0067] This application discloses a multilayer capacitor welding production process, based on the aforementioned multilayer capacitor welding apparatus, with reference to... Figure 1 , Figure 2 and Figure 3 It includes the following steps:

[0068] S1. Fix multiple patches 22 sequentially onto the lead frame 21, and fix the lead frame 21 with a pressure plate. Then, use a conveying mechanism to intermittently convey the lead frame 21 so that each patch 22 on the lead frame 21 passes under the turntable 4 sequentially and stays for a set time.

[0069] S2. When a single patch 22 is positioned below the turntable 4, the two positioning plates 71 first press and fix the patch 22 on both sides. Then, the welding controller controls the drive unit 32 to operate. The drive unit 32 drives the turntable 4 to rotate, causing a group of multiple piercing needles 52 on it to rotate and pierce the patch 22, prying up multiple protrusions 221. Figure 2 and Figure 3 As shown.

[0070] S3. The welding controller continues to control the drive unit 32, which drives the turntable 4 to continue rotating so that the laser channel 41 is aligned with the laser welding head 31. The welding controller then controls the laser welding head 31 to work and weld the multiple protrusions 221 on the patch 22. Figure 5 As shown.

[0071] S4. After welding is completed, the turntable 4 continues to rotate and hot-presses the welded parts on the patch 22. Hot-pressing of the welded parts on the patch 22 is performed within 3 seconds of welding completion, with a hot-pressing temperature of not less than 120℃. If necessary, ultrasonic vibration hot-pressing may be used during the hot-pressing process. Figure 6 and Figure 7 As shown.

[0072] 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. Repeat steps S2 to S4.

[0073] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0074] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A multilayer capacitor welding apparatus, comprising a worktable (1) and a pressure plate for pressing a lead frame (21), characterized in that, The workbench (1) is provided with a conveying mechanism for intermittently moving the lead frame (21). 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), and a turntable (4) is rotatably arranged in the middle. A drive unit (32) for driving the turntable (4) to rotate is provided. A laser channel (41) is provided on the outer peripheral wall of the arc surface of the turntable (4) along its radial direction, through which the welding laser of the laser welding head (31) can pass. A number of puncture seats (51) are fixed on the outer peripheral wall of the arc surface of the turntable (4). A number of puncture needles (52) arranged in an array are fixed on the side of the puncture seat (51) away from the turntable (4). The drive unit (32) and the laser welding head (31) are 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) to the bottom of the turntable (4), the control drive (32) drives the turntable (4) to rotate and pierce the single-layer patch (22) with the help of multiple piercing needles (52) and rotates to pry up the protrusions (221) composed of part of metal pads and aluminum foil, until the turntable (4) rotates to the point where the laser channel (41) on it is aligned with the laser welding head (31), and then controls the laser welding head (31) to weld the multiple protrusions (221) on the patch (22).

2. The laminated capacitor welding apparatus according to claim 1, characterized in that, The tip of the puncture needle (52) is conical, so that the barbs (221) that it pry up on the patch (22) have a barb-like structure.

3. The laminated capacitor welding apparatus according to claim 2, characterized in that, The outer peripheral wall of the tip of the puncture needle (52) is provided with a spiral groove (521).

4. The laminated capacitor welding apparatus according to claim 1, characterized in that, The multiple puncture needles (52) on two adjacent puncture seats (51) are staggered.

5. The multilayer capacitor welding apparatus according to any one of claims 1-4, characterized in that, The turntable (4) is also provided with a number of spinning heads (6) on its outer peripheral wall. The rotational contact area between the spinning head (6) and a single patch (22) is not less than the welding area on the patch (22). A spin press 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 arranged sequentially at intervals along the rotation direction of the turntable (4) starting from the spin press head (6).

6. The laminated capacitor welding apparatus according to claim 5, characterized in that, The spinning head (6) is provided with an electric heating element (61), and the welding controller is also configured to control the turntable (4) to rotate to the spinning head (6) to perform hot pressing on the welding area on the patch (22) within 3 seconds after the laser welding head (31) finishes welding.

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

8. The laminated capacitor welding apparatus according to claim 5, characterized in that, The welding seat (3) is provided with a positioning plate (71) for pressing the patch (22) onto the lead frame (21). There are two positioning plates (71) 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 trajectory of the puncture needle (52) and the spin head (6).

9. A multilayer capacitor welding production process, based on the multilayer capacitor welding apparatus as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Fix multiple patches (22) sequentially on the lead frame (21), and fix the lead frame (21) by the pressure plate. Then, use the conveying mechanism to intermittently convey the lead frame (21) so that each patch (22) on the lead frame (21) passes under the turntable (4) sequentially and stays for a set time. S2. When a single patch (22) is positioned below the turntable (4), the welding controller controls the drive (32) to operate, and the drive (32) drives the turntable (4) to rotate so that a group of multiple puncture needles (52) on it rotate to puncture the patch (22) and pry up multiple protrusions (221). S3. The welding controller continues to control the drive unit (32) to work, and the drive unit (32) drives the turntable (4) to continue to rotate so that the laser channel (41) is aligned with the laser welding head (31). The welding controller then controls the laser welding head (31) to work to weld the multiple protrusions (221) on the patch (22). S4. After welding is completed, the turntable (4) continues to rotate and hot presses the welding 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 below the turntable (4), and repeats steps S2 to S4.

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

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