Capacitor winding core and busbar welding method, welding system and capacitor

Abstract

The embodiment of the application relates to the technical field of capacitor assembly, solves the problem of poor solderability of tin soldering on aluminum and other metal busbars, and discloses a capacitor winding core and busbar welding method, a welding system and a capacitor, wherein the capacitor winding core and busbar welding method comprises the following steps: after the busbar is arranged on the capacitor winding core, a first pulse laser is emitted to the busbar, a molten pool is formed when the laser contacts the busbar, the molten pool is cooled in a pulse interval period, so that the busbar is welded on the capacitor winding core, and non-contact precise welding is realized. Through the single high-energy-density and low-energy-total-input mode, the heat-affected zone of the welding point is extremely small, the formation of brittle intermetallic compounds can be inhibited for the welding of heterogeneous busbar materials, the mechanical performance of the welding point can be greatly improved, and the laser welding of the capacitor winding core and various material busbars is provided with the possibility. Compared with traditional tin soldering, the first pulse laser welding does not need to introduce external materials and does not need to consume materials, and has a larger material application range.

Description

Technical Field

[0001] This invention relates to the field of capacitor assembly technology, and in particular to a method, welding system and capacitor for welding capacitor core and busbar. Background Technology

[0002] In the field of capacitor manufacturing (especially film capacitors and metallized film capacitors), the electrode connection process between the capacitor core and the busbar directly affects the product's conductivity, mechanical strength, and long-term reliability. Traditional processes commonly use soldering assembly, which has the following drawbacks: High dependence on solder: A large amount of tin-based solder is required to fill the gaps, which is costly and prone to cracking due to differences in thermal expansion coefficients; Poor material compatibility: Tin soldering has good welding performance for copper / copper alloys, but poor wetting performance for metals and alloys such as aluminum and nickel, resulting in poor solderability; High-temperature soldering may also damage thin film dielectrics; In addition, tin soldering requires precise control of solder quantity and temperature, has a narrow process window, and is difficult to adapt to high-speed automated production lines; Soldering requires the introduction of tin solder consumables, resulting in high soldering costs. Summary of the Invention

[0003] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This part of the invention is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0005] Therefore, a first aspect of the present invention provides a method for welding capacitor cores to busbars.

[0006] A second aspect of the present invention provides a welding system.

[0007] A third aspect of the present invention provides a capacitor.

[0008] In view of this, a method for welding a capacitor core to a busbar is proposed according to a first aspect of the embodiments of this application, comprising: Provide capacitor winding cores and busbars; The capacitor core and the busbar are pre-processed; The pre-processed busbar is placed on the capacitor core; A first pulse laser is emitted to the busbar, and a molten pool is formed when the laser comes into contact with the busbar. The molten pool cools and solidifies during the pulse interval, so that the busbar is welded to the capacitor core. The emission power of the first laser pulse emitted to the busbar is greater than the emission power of subsequent laser pulses.

[0009] In one feasible implementation, a plurality of pads are provided between the capacitor core and the busbar, each pad comprising a plurality of solder joints. The step of emitting a first pulsed laser to the busbar, forming a molten pool upon contact with the busbar, and cooling the molten pool during the pulse interval to weld the busbar onto the capacitor core includes: The pulse width of the first laser pulse is 2ns to 500ns; The laser is activated a first time interval in advance to emit the first laser beam, forming the molten pool on the busbar; The emission direction of the first pulsed laser is changed to emit subsequent lasers, forming other molten pools on the busbar; After the molten pool solidifies, the weld joint is formed; The ratio of the emission power of the first laser to the emission power of the subsequent laser is 1.2 to 1.5.

[0010] In one feasible implementation, the method for welding the capacitor core to the busbar further includes: After emitting the first pulse laser, a second pulse laser is emitted; The second pulsed laser is staggered with the first pulsed laser, and the projection direction of the second pulsed laser is located within the molten pool. The second pulsed laser is used to assist melting and expand the area of ​​the molten pool. The emission power of the second pulsed laser is lower than that of the first pulsed laser, and the pulse width of the second pulsed laser is the same as that of the first pulsed laser.

[0011] In one feasible implementation, the method for welding the capacitor core to the busbar further includes: After emitting the second pulse laser, a cooling gas flow is emitted to the area where the molten pool is located to reduce the temperature of the busbar.

[0012] In one feasible implementation, the ratio of the emission power of the second pulsed laser to the emission power of the first pulsed laser is 0.5 to 0.7. The emission power of subsequent lasers following the first pulse laser is determined based on the laser absorptivity of the busbar, the thickness of the busbar, the pitch, and the flatness of the capacitor core.

[0013] In one feasible implementation, the emission power of subsequent laser beams following the first pulse laser is determined based on the following formula:

[0014] Where P0 is the preset power, I is the laser absorptivity of the busbar, D is the thickness of the busbar, d is the pitch, S is the flatness of the capacitor core, P is the emission power of the subsequent laser, and K is the correction coefficient.

[0015] In one feasible implementation, the step of preprocessing the capacitor core and the busbar includes: Clean the capacitor core and the busbar; A welding area is defined on the capacitor core, and a portion of the gold plating layer within the welding area on the capacitor core is removed.

[0016] According to a second aspect of the embodiments of this application, a welding system is provided for implementing the capacitor core and busbar welding method as described in any of the above technical solutions, the welding system comprising: First pulse laser emitting component; The first galvanometer is positioned so that the light emission direction of the first pulsed laser emitting component is oriented toward the first galvanometer. An air-cooled system, wherein the output direction of the air-cooled system is oriented toward the busbar.

[0017] In one feasible implementation, the welding system further includes: Second pulse laser emitting component; The second galvanometer is positioned so that the light emission direction of the second pulsed laser emitting component is oriented toward the second galvanometer.

[0018] A capacitor is provided according to a third aspect of the embodiments of this application, the capacitor comprising: The capacitor core and the busbar are welded together by the capacitor core and busbar welding method described in any of the above technical solutions. The busbar is connected to the capacitor core via multiple solder pads, and each solder pad includes multiple solder joints.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects: The capacitor core and busbar welding method provided in this application involves placing the busbar on top of the capacitor core and then emitting a first pulse laser onto the busbar. When the laser contacts the busbar, a molten pool forms. The molten pool cools and solidifies during the pulse interval, thus welding the busbar to the capacitor core, achieving non-contact precision welding. The high energy density and low total energy input of a single pulse minimize the heat-affected zone of the weld joint. For welding dissimilar busbar materials, it suppresses the formation of brittle intermetallic compounds, significantly improving the mechanical properties of the weld joint and providing the possibility for laser welding of capacitor cores to busbars of various materials. Compared to traditional soldering, first-pulse laser welding requires no external materials or consumables, offering a wider range of applicable materials. It solves the problem of soldering aluminum, which is difficult to weld. This method is applicable to welding busbars of different materials (aluminum, copper, zinc, nickel, etc.) to the gold-plated layer of the core, ensuring the reliability of the connection between the busbar and the capacitor core.

[0020] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0021] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic flowchart illustrating the steps of a capacitor winding core and busbar welding method according to an embodiment of this application; Figure 2 A schematic structural diagram of a welding system according to an embodiment of this application; Figure 3 A schematic structural diagram of a capacitor according to an embodiment of this application; Figure 4 This is a schematic structural diagram of the solder joints of a capacitor according to one embodiment of the present application.

[0022] in, Figure 2 and Figure 3 The correspondence between the reference numerals and component names in the attached drawings is as follows: 110 First pulse laser emitting component, 120 First galvanometer, 130 Air cooling system; 111 Master oscillator, 112 Amplifier, 113 Focusing lens; 210 capacitor winding core, 220 busbar; 310 pad, 311 solder joint. Detailed Implementation

[0023] The following description provides numerous specific details to offer a more thorough understanding of the technical solutions provided by this invention. However, it will be apparent to those skilled in the art that the technical solutions provided by this invention can be implemented without one or more of these details.

[0024] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0025] Exemplary embodiments according to the present invention will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of the invention is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art.

[0026] like Figure 1 As shown, a method for welding a capacitor core to a busbar is provided according to a first aspect of an embodiment of this application, comprising: Step 101: Provide capacitor winding cores and busbars; Step 102: Pre-process the capacitor core and busbar; Step 103: Place the pre-treated busbar onto the capacitor core; Step 104: A first pulse laser is emitted to the busbar. When the laser comes into contact with the busbar, a molten pool is formed. The molten pool cools and solidifies during the pulse interval so that the busbar is welded to the capacitor core. Among them, the emission power of the first laser in the first pulse laser emitted to the busbar is greater than the emission power of the subsequent lasers emitted.

[0027] The capacitor core and busbar welding method provided in this application involves placing the busbar on top of the capacitor core and then emitting a first pulse laser onto the busbar. When the laser contacts the busbar, a molten pool forms. The molten pool cools and solidifies during the pulse interval, thus welding the busbar to the capacitor core, achieving non-contact precision welding. The high energy density and low total energy input of a single pulse minimize the heat-affected zone of the weld joint. For welding dissimilar busbar materials, it suppresses the formation of brittle intermetallic compounds, significantly improving the mechanical properties of the weld joint and providing the possibility for laser welding of capacitor cores to busbars of various materials. Compared to traditional soldering, first-pulse laser welding requires no external materials or consumables, offering a wider range of applicable materials. It solves the problem of soldering aluminum, which is difficult to weld. This method is applicable to welding busbars of different materials (aluminum, copper, zinc, nickel, etc.) to the gold-plated layer of the core, ensuring the reliability of the connection between the busbar and the capacitor core.

[0028] The capacitor core and busbar welding method provided in this application embodiment uses a first pulse laser welding to melt the busbar and / or capacitor core, and then the molten pool solidifies to form a weld point. This welding method can increase the reliability of the connection between the busbar and the capacitor core, increase the contact area between the two, and ensure the reliability of the conduction between the capacitor core and the busbar.

[0029] The capacitor core and busbar welding method provided in this application takes into account the consistency of the welding between the capacitor core and the busbar. For the first laser emitted by the first pulse laser, that is, the first laser, the first laser has a greater emission power than the subsequent lasers. When the first laser comes into contact with the relatively low temperature busbar, it can form a molten pool that is very similar to that formed by the subsequent lasers. This can ensure the consistency between all welding points of the busbar and the capacitor core, thereby ensuring the quality of the capacitor.

[0030] In one feasible implementation, a plurality of pads are provided between the capacitor core and the busbar, each pad including a plurality of solder joints. A first pulse laser is emitted to the busbar, and a molten pool is formed when the laser contacts the busbar. The molten pool cools during the pulse interval to weld the busbar onto the capacitor core. The steps include: the pulse width of the first pulse laser is 2ns to 500ns; the laser is started a first time in advance to emit the first laser and form a molten pool on the busbar; the emission direction of the first pulse laser is changed to emit subsequent lasers to form other molten pools on the busbar; after the molten pools solidify, solder joints are formed; wherein the ratio of the emission power of the first laser to the emission power of the subsequent lasers is 1.2 to 1.5.

[0031] This technical solution further provides specific steps for welding using a first pulse laser. The pulse width of the first pulse laser is 2ns to 500ns. This setting allows the molten pool to cool and solidify during the pulse interval, ensuring the reliability of the welding between the busbar and the capacitor core. The ratio of the emission power of the first laser to the emission power of subsequent lasers is 1.2 to 1.5, which ensures the consistency between all weld points on the busbar and the capacitor core, thereby guaranteeing the quality of the capacitor.

[0032] In some examples, the first duration can be 0.1s.

[0033] In one feasible implementation, the method for welding the capacitor core to the busbar further includes: emitting a second pulse laser after emitting a first pulse laser; wherein the second pulse laser and the first pulse laser are staggered, and the projection direction of the second pulse laser is located within the molten pool, using the second pulse laser to assist melting and expand the area of ​​the molten pool; wherein the emission power of the second pulse laser is lower than that of the first pulse laser, and the pulse width of the second pulse laser is the same as that of the first pulse laser.

[0034] In this technical solution, in addition to emitting a first pulse laser to the busbar, a second pulse laser can be emitted during the pulse interval after the first pulse laser. The emission power of the second pulse laser is lower than that of the first pulse laser, and the second pulse laser and the first pulse laser are output in a non-confocal manner, allowing the second pulse laser to also be projected onto the area where the molten pool is located. The second pulse laser can further promote the formation of the molten pool, increasing the area of ​​the molten pool without excessively increasing the depth, thereby improving the welding strength and contact area between the busbar and the capacitor core. Furthermore, by using the same pulse width for the second pulse laser as the first pulse laser, the same working cycle can be used to weld the busbar and the capacitor core.

[0035] In one feasible implementation, the method for welding the capacitor core to the busbar further includes: after emitting the second pulse laser, emitting a cooling gas flow to the area where the molten pool is located to reduce the temperature of the busbar.

[0036] In this technical solution, the product temperature is reduced during the pulse interval of the second pulse laser to avoid the influence of welding temperature on other components.

[0037] In one feasible implementation, the ratio of the emission power of the second pulse laser to the emission power of the first pulse laser is 0.5 to 0.7.

[0038] In this technical solution, the relationship between the second pulse laser and the first pulse laser is further provided. The ratio of the emission power of the second pulse laser to the emission power of the first pulse laser is 0.5 to 0.7. Based on this, it is ensured that the role of the second pulse laser is to assist in melting, and will not increase the depth of the molten pool too much. Instead, it combines with the first pulse laser to expand the area of ​​the molten pool, thereby increasing the contact area between the capacitor core and the busbar.

[0039] In one feasible implementation, the emission power of subsequent lasers following the first pulse laser is determined based on the laser absorptivity of the busbar, the thickness of the busbar, the distance between two adjacent solder joints, and the flatness of the capacitor core.

[0040] This technical solution further provides a method for determining the subsequent laser of the first pulse laser. The subsequent laser is determined using parameters such as the laser absorptivity of the busbar, the thickness of the busbar, the distance between two adjacent welding points, and the flatness of the capacitor core. Specifically, the emission power of the subsequent laser is inversely proportional to the laser absorptivity of the busbar and the flatness of the capacitor core, and directly proportional to the thickness of the busbar and the distance between two adjacent welding points. After determining the emission power of the subsequent laser, the emission power of the first laser and the emission power of the second pulse laser can be determined based on the emission power of the subsequent laser, thereby achieving reliable control of the capacitor core and busbar welding method. At the same time, the emission power of the pulse laser welding can be related to the laser absorptivity of the busbar, the thickness of the busbar, the distance between two adjacent welding points, and the flatness of the capacitor core, making the capacitor core and busbar welding method adaptable to the welding of busbars and capacitor cores of different materials, thicknesses, and specifications, thus increasing the adaptability of the capacitor core and busbar welding method.

[0041] In some examples, the power of the first pulse laser is greater than 200 kHz to ensure the overall heat input of the solder joint.

[0042] Understandably, solder joints can be spiral or involute, and the distance between two adjacent solder lines is the pitch. Figure 4 As shown, the distance d is the pitch, which directly affects the welding density. Theoretically, the smaller the pitch, the greater the welding density. However, an excessively small pitch will increase the energy input, and the weld joints will become brittle and the number of defects will increase. To meet the welding quality requirements, the pitch is generally selected in the range of 0.1-1mm, depending on the busbar material and plate thickness.

[0043] In one feasible implementation, the emission power of subsequent laser beams following the first laser pulse is determined based on the following formula:

[0044] Where P0 is the preset power, I is the laser absorptivity of the busbar, D is the thickness of the busbar, d is the pitch, S is the flatness of the capacitor core, P is the emission power of the subsequent laser, and K is the correction coefficient.

[0045] This technical solution further provides a method for determining the emission power of subsequent lasers. This setting facilitates the determination of the emission power of subsequent lasers through computer programs. Consequently, the emission power of the first laser and the second pulse laser can be determined based on the emission power of subsequent lasers, achieving reliable control of the capacitor core and busbar welding method. At the same time, the emission power of pulsed laser welding can be related to the laser absorptivity of the busbar, the thickness of the busbar, the pitch, and the flatness of the capacitor core. This makes the capacitor core and busbar welding method adaptable to the welding of busbars and capacitor cores of different materials, thicknesses, and specifications, increasing the adaptability of the capacitor core and busbar welding method.

[0046] In one feasible implementation, the pretreatment steps for the capacitor core and busbar include: cleaning the capacitor core and busbar; identifying the welding area on the capacitor core; and removing part of the gold plating layer in the welding area on the capacitor core to smooth the welding area.

[0047] This technical solution further provides a pre-treatment step for the capacitor core and busbar, which can clean the capacitor core and busbar to reduce the impact of dirt on laser welding. At the same time, it can also treat the gold spraying layer in the welding area of ​​the capacitor core, removing part of the thickness of the gold spraying layer to make the welding area of ​​the capacitor core flatter, thereby enabling a larger contact area between the busbar and the capacitor core and ensuring the welding effect.

[0048] like Figure 2 and Figure 3 As shown, according to a second aspect of the embodiments of this application, a welding system is proposed for implementing the welding method of capacitor core 210 and busbar 220 as described in any of the above technical solutions. The welding system includes: a first pulsed laser emitting component 110; a first galvanometer 120, the light emission direction of the first pulsed laser emitting component 110 is oriented toward the first galvanometer 120; and an air cooling system 130, the output direction of the air cooling system 130 is oriented toward the busbar 220.

[0049] The welding system provided in this application embodiment is used to implement the welding method of capacitor core 210 and busbar 220 as described in any of the above technical solutions. Therefore, the welding system has all the beneficial effects of the above-described welding method of capacitor core 210 and busbar 220.

[0050] The welding system provided in this application includes a first pulsed laser emitting component 110, a first galvanometer 120, and an air-cooling system 130. Based on this, during the use of the welding system, the first pulsed laser emitting component 110 can emit a first pulsed laser. When the laser comes into contact with the busbar 220, a molten pool is formed. Then, the air-cooling system 130 can emit a cooling airflow to promote the solidification of the molten pool. Afterward, the first galvanometer 120 is used to adjust the light emission direction of the first pulsed laser emitting component 110 to form the next molten pool until the busbar 220 and the capacitor core 210 are welded together, ensuring efficient welding of the busbar 220 and the capacitor core 210.

[0051] In one feasible implementation, the welding system further includes: a second pulsed laser emitting assembly; and a second galvanometer, wherein the light emission direction of the second pulsed laser emitting assembly is oriented toward the second galvanometer.

[0052] In this technical solution, the structural composition of the welding system is further provided. The welding system may also include a second pulse laser emitting component and a second galvanometer. The second pulse laser emitting component is used to emit a second pulse laser to assist in the dissolution process, and the second galvanometer is used to adjust the light emission direction of the second pulse laser emitting component.

[0053] In some examples, the first pulsed laser emitting component 110 and the second pulsed laser emitting component can have the same structure. The main difference between them is the emission power and the position of the projected laser. Similarly, the first galvanometer 120 and the second galvanometer can also have the same structure. Taking the first pulsed laser emitting component 110 as an example, the first pulsed laser emitting component 110 can include a master oscillator 111, an amplifier 112, and a focusing lens 113. During the operation of the first pulsed laser emitting component 110, the master oscillator 111 generates seed laser pulses with nanosecond-level adjustable pulse width (2-500 ns) and frequency (1-4000 kHz). These pulses are then boosted to kilowatt-level peak power (up to 15 kW) by a multi-stage amplifier 112 and then incident perpendicularly on the workpiece surface through the focusing lens 113. Each pulse delivers high energy density (>10) in a very short time. 6 W / cm 2 The oxide layer on the material surface is broken through to form an instantaneous molten pool, which is then rapidly cooled and solidified during the pulse interval. The position of the weld point 311 is switched at high speed by the first galvanometer 120 (scanning speed > 500 mm / s) to achieve non-contact precision welding.

[0054] In some examples, the first galvanometer 120 and the second galvanometer are parallel to the welding surface, which makes it easy to ensure beam positioning accuracy and scanning stability.

[0055] like Figure 3 As shown, a capacitor is provided according to a third aspect of the embodiments of this application. The capacitor includes: a capacitor core 210 and a busbar 220. The capacitor core 210 and the busbar 220 are welded together by the capacitor core 210 and the busbar 220 welding method as described in any of the above technical solutions. The busbar 220 is connected to a plurality of capacitor cores 210 by a plurality of solder pads 310, and each solder pad 310 includes a plurality of solder points 311.

[0056] The capacitor provided in this application embodiment is welded using the capacitor core 210 and busbar 220 welding method of any of the above technical solutions. Therefore, the capacitor has all the beneficial effects of the capacitor core 210 and busbar 220 welding method of the above technical solutions, which will not be elaborated here.

[0057] The capacitor provided in this application embodiment has a busbar 220 connected to the capacitor core 210 via multiple solder pads 310, which ensures the reliability of the connection between the busbar 220 and the capacitor core 210. Each solder pad 310 includes multiple solder points 311, which can ensure the service life of the capacitor.

[0058] In this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0059] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0060] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0061] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for welding capacitor cores to busbars, characterized in that, include: Provide capacitor winding cores and busbars; The capacitor core and the busbar are pre-processed; The pre-processed busbar is placed on the capacitor core; A first pulse laser is emitted to the busbar. When the first pulse laser contacts the busbar, a molten pool is formed. The molten pool cools and solidifies during the pulse interval, so that the busbar is welded to the capacitor core. After emitting the first pulse laser, a second pulse laser is emitted; The emission power of the first laser pulse emitted into the busbar is greater than the emission power of the subsequent laser pulses. The capacitor core and the busbar have multiple solder pads, each solder pad including multiple solder joints. The step of emitting a first pulse laser to the busbar, forming a molten pool when the laser contacts the busbar, and the molten pool cooling and solidifying during the pulse interval to weld the busbar to the capacitor core includes: The pulse width of the first pulse laser is 2ns to 500ns; The laser is activated a first time interval in advance to emit the first laser beam, forming the molten pool on the busbar; The emission direction of the first pulsed laser is changed to emit subsequent lasers, forming other molten pools on the busbar; After the molten pool solidifies, the weld joint is formed; The ratio of the emission power of the first laser to the emission power of the subsequent lasers is 1.2 to 1.

5. The second pulsed laser is staggered with the first pulsed laser, and the projection direction of the second pulsed laser is located within the molten pool. The second pulsed laser is used to assist melting and expand the area of ​​the molten pool. The emission power of the second pulsed laser is lower than that of the first pulsed laser, and the pulse width of the second pulsed laser is the same as that of the first pulsed laser.

2. The method for welding capacitor core and busbar according to claim 1, characterized in that, Also includes: After emitting the second pulse laser, a cooling gas flow is emitted to the area where the molten pool is located to reduce the temperature of the busbar.

3. The method for welding capacitor core and busbar according to claim 1, characterized in that, The ratio of the emission power of the second pulsed laser to the emission power of the first pulsed laser is 0.5 to 0.7; The emission power of the subsequent laser of the first pulse laser is determined based on the laser absorptivity of the busbar, the thickness of the busbar, the distance between two adjacent solder joints, and the flatness of the capacitor core.

4. The method for welding capacitor core and busbar according to any one of claims 1 to 3, characterized in that, The preprocessing steps for the capacitor core and the busbar include: Clean the capacitor core and the busbar; A welding area is defined on the capacitor core, and a portion of the gold plating layer within the welding area on the capacitor core is removed.

5. A welding system, characterized in that, For implementing the method of welding capacitor core and busbar as described in any one of claims 1 to 4, the welding system comprises: First pulse laser emitting component; The first galvanometer is positioned so that the light emission direction of the first pulsed laser emitting component is oriented toward the first galvanometer. An air-cooled system, wherein the output direction of the air-cooled system is oriented toward the busbar.

6. The welding system according to claim 5, characterized in that, Also includes: Second pulse laser emitting component; The second galvanometer mirror is positioned so that the light emission direction of the second pulsed laser emitting component is oriented toward the second galvanometer mirror. A clamping element is used to apply pressure to the busbar so that the busbar is flat against the capacitor core.

7. A capacitor, characterized in that, The capacitor includes: A capacitor core and a busbar, wherein the capacitor core and the busbar are welded together by the capacitor core and busbar welding method as described in any one of claims 1 to 4; The busbar is connected to the capacitor core via multiple solder pads, and each solder pad includes multiple solder joints.

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