A thin film capacitor

Abstract

This invention discloses a thin-film capacitor, including a housing, a capacitor core, and an electrode assembly. The electrode assembly includes an external electrode and an internal electrode, with the internal electrode integrating solder pins. When the internal electrode is made of low-cost non-pure copper materials such as aluminum, aluminum alloy, or steel, the solder pins are partially coated to ensure the solderability of the electrode and the core, and to ensure reliable connection. When the external electrode is entirely made of low-cost non-pure copper materials such as aluminum, aluminum alloy, or steel, the exposed terminals are also coated to ensure the conductivity of the non-copper electrodes and the terminals, and to reduce contact resistance.

Description

Technical Field

[0001] This invention relates to the field of capacitor technology, and in particular to a thin-film capacitor. Background Technology

[0002] Film capacitors are among the most widely used electronic components in electronic devices. They are widely used in DC blocking, coupling, bypassing, filtering, tuning circuits, energy conversion and control circuits, and their applications in new energy fields such as photovoltaics, solar energy and electric vehicles are becoming increasingly widespread.

[0003] Current film capacitors primarily use copper as the electrode material. Copper's excellent electrical and thermal conductivity, stability, and moderate mechanical properties ensure good capacitor performance. However, the soaring price of copper in recent years has increased the cost of film capacitors. Reducing the amount of copper used and balancing electrode quality and cost is one of the important ways for the industry to reduce costs.

[0004] Existing cost-reduction designs attempt to replace the internal electrodes with aluminum instead of copper, but without surface treatment, aluminum is difficult to weld to the core; if the internal aluminum electrodes are surface treated as a whole, it will increase the additional cost, making it impossible to effectively balance cost and performance. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in the aforementioned technologies. Therefore, the object of this invention is to provide a thin-film capacitor that improves solderability while simplifying the structure and reducing costs, while ensuring the reliability of the electrode and core connection, ultimately reducing costs while maintaining the performance of the thin-film capacitor.

[0006] To achieve the above objectives, embodiments of the present invention provide a thin-film capacitor comprising: The shell has a receiving cavity; The capacitor core is disposed within the receiving cavity; An electrode assembly includes an external electrode and an internal electrode. The internal electrode is made of a non-pure copper conductive material and is disposed within the receiving cavity. The internal electrode includes a main body and a welding pin integrated on the main body. The surface of the welding pin is coated with a solderable coating layer through a local coating process. The welding pin is brazed to the capacitor core through the solderable coating layer. The main body and the internal electrode are overlapped and fixed to realize the power conduction between the capacitor core and the internal electrode. The external electrode is fixedly connected to the internal electrode or integrally formed to lead out the power of the capacitor core.

[0007] According to an embodiment of the present invention, a thin-film capacitor eliminates the need for separate transfer electrodes. Instead, a soldering pin structure is integrated directly onto the internal electrodes, which are made of non-pure copper. A solderable coating is formed by locally coating the soldering pin area, directly achieving brazing between the internal electrodes and the capacitor core. This eliminates the need for transfer electrode components and their assembly processes, simplifying the production process. Simultaneously, it avoids lap contact resistance between the transfer electrodes and the internal electrodes, improving connection reliability and power conduction efficiency. The internal electrodes can be made of low-cost non-pure copper conductive materials such as aluminum, aluminum alloys, or steel. Local coating on the soldering pins further reduces copper usage and surface treatment costs, resulting in lower overall material costs. This reduces the proportion of copper used in the electrodes, lowering electrode costs while ensuring reliable connection between the electrodes and the core, ultimately reducing costs while maintaining the performance of the thin-film capacitor.

[0008] Optionally, the external electrode is made of a non-pure copper conductive material, and the exposed terminal surface of the external electrode is coated with a conductive protective layer to reduce contact resistance.

[0009] Embodiments of the present invention also provide another thin-film capacitor, which includes: The shell has a receiving cavity; The capacitor core is disposed within the receiving cavity; An electrode assembly includes an external electrode and an internal electrode; the internal electrode is disposed within the receiving cavity; the internal electrode includes a main body and a welding pin integrated on the main body, the welding pin being brazed to the capacitor core, and the main body being overlapped and fixed to the internal electrode to achieve power conduction between the capacitor core and the internal electrode; the external electrode is fixedly connected to or integrally formed with the internal electrode to lead out the power of the capacitor core, the external electrode is made of a non-pure copper conductive material, and the exposed terminal surface of the external electrode is formed with a conductive protective layer through a local coating process to reduce contact resistance.

[0010] According to a second embodiment of the present invention, this film capacitor achieves multiple benefits while ensuring performance by combining a non-pure copper external electrode design with a localized coating process for exposed terminals. Firstly, it significantly reduces overall material costs. For example, low-cost non-pure copper conductive materials such as aluminum, aluminum alloys, and stainless steel can be used to replace traditional pure copper external electrodes, reducing electrode material costs and effectively offsetting the impact of copper price fluctuations on the supply chain. Simultaneously, the conductive protective layer is formed only in the exposed terminal area, reducing the coating area compared to traditional overall electroplating processes, thus significantly reducing the consumption of precious metal plating and surface treatment costs. Secondly, in terms of electrical performance and reliability, the conductive protective layer of the exposed terminals prevents oxidation and corrosion of the non-pure copper substrate, reducing contact resistance with external connecting components. Furthermore, the weight of the non-pure copper external electrode is reduced compared to pure copper solutions, allowing for flexible matching of substrate and plating combinations for different scenarios. It is particularly suitable for fields with high requirements for lightweighting and environmental adaptability, such as new energy vehicles and photovoltaic energy storage. Ultimately, it achieves overall cost reduction while maintaining product performance, giving it a significant competitive advantage in the market.

[0011] Optionally, the non-pure copper conductive material is one of pure aluminum, aluminum alloy, or steel.

[0012] Optionally, the local coating process is at least one of cold spraying copper powder, cold spraying tin powder, local copper plating, local nickel plating, local tin plating, or nickel sheet bonding.

[0013] Optionally, the number of partially coated surfaces of the welding needle is at least one surface.

[0014] Optionally, the welding needle and the main body are integrally stamped and formed.

[0015] Optionally, the external electrode and the internal electrode are fixedly connected by laser welding, ultrasonic welding, molecular diffusion welding, brazing or mechanical riveting, or the external electrode and the internal electrode are integrally stamped.

[0016] Optionally, the thickness of the solderable coating is 0.001 mm to 0.6 mm.

[0017] Optionally, the thickness of the conductive protective layer is 0.001mm-0.6mm. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a thin-film capacitor according to Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the internal structure of a thin-film capacitor according to Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the electrode assembly according to Embodiment 1 of the present invention; Figure 4This is a schematic diagram of the electrode assembly according to Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of the electrode assembly according to Embodiment 3 of the present invention; Figure 6 This is a schematic diagram of the electrode assembly according to Embodiment 4 of the present invention.

[0019] Label Explanation: Shell 1, Receiving cavity 110; Capacitor core 2; Electrode assembly 3, external electrode 310, positive external electrode 310a, negative external electrode 310b, internal electrode 320, positive internal electrode 320a, negative internal electrode 320b, main body 321, welding pin 322, solderable coating layer 323, and perforated hole 324; Filler 4. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0021] The following is in conjunction with the appendix Figures 1-4 A thin-film capacitor according to an embodiment of the present invention is described in detail.

[0022] Example 1 like Figures 1-3 As shown, the thin-film capacitor according to an embodiment of the present invention includes a housing 1, a capacitor core 2, an electrode assembly 3, and a filler 4.

[0023] Specifically, the housing 1 has a receiving cavity 110; capacitor cores 2 are disposed within the receiving cavity 110, and the number of capacitor cores 2 is one or more, with multiple capacitor cores 2 arranged in a single row or multiple rows array within the receiving cavity 110 (e.g., Figure 2 As shown); the electrode assembly 3 includes an external electrode 310 and an internal electrode 320; the internal electrode 320 is made of a non-pure copper conductive material and is disposed in the receiving cavity 110. The internal electrode 320 includes a main body 321 and a welding pin 322 integrated on the main body. A solderable coating layer 323 is formed on the surface of the welding pin 322 through a local coating process. The welding pin 322 is brazed to the capacitor core 2 through the solderable coating layer 323; the external electrode 310 is made of a conductive material (e.g., copper, copper alloy, etc.); the external electrode 310 is fixedly connected to the internal electrode 320 to lead out the power of the capacitor core 2.

[0024] In other words, this application does not require an additional independent transfer electrode. The welding needle 322 is integrally stamped on the internal electrode 320, which is made of non-pure copper conductive material. The area of ​​the welding needle 322 is locally coated to form a solderable coating layer 323, which can directly realize the brazing connection between the internal electrode 210 and the capacitor core 2. This eliminates the need for transfer electrode parts and their assembly process, simplifies the production process, and avoids the lap contact resistance between the transfer electrode and the internal electrode 320, thus improving the connection reliability.

[0025] Specifically, the welding needle 322 extends from a predetermined edge of the main body 321 of the internal electrode 320 in a direction orthogonal to the thickness direction of the main body 321. The welding needle 322 and the main body 321 are integrally stamped structures, requiring no additional connection process, resulting in higher structural strength. The solderability coating layer 323 has a thickness of 0.05mm, ensuring good solderability while avoiding excessively thick coating layers that would increase costs.

[0026] In specific examples, the local coating process includes at least one of the following: cold spray copper powder, cold spray tin powder, local copper plating, local nickel plating, local tin plating, and nickel foil bonding. The cold spray copper powder process uses a high-pressure airflow to accelerate micron-sized copper powder particles to supersonic speeds, directly spraying them onto the surface of the solder pin 322 to form a dense coating layer. The process temperature is below 150℃, which does not affect the mechanical properties of the internal electrode substrate material. The bonding strength between the coating layer and the substrate is ≥50MPa, suitable for surface treatment of easily deformable substrate materials such as aluminum and aluminum alloys. The brazing wetting angle of the coated solder pin 322 is ≤30°, exhibiting excellent solderability. The cold spray tin powder process deposits a tin or tin alloy coating on the surface of the solder pin 322 using a cold spray process. The surface roughness Ra of the coating layer is ≤1.6μm, and the coating layer has good oxidation resistance, suitable for applications with high storage cycle requirements. The partial copper plating process involves masking the non-soldering pin area of ​​the internal electrode 320 and then plating copper on the soldering pin 322 area. The coating uniformity error is ≤±5μm, exhibiting strong adhesion to the substrate and excellent conductivity, making it suitable for high-current applications requiring high current conduction efficiency. The partial nickel plating process involves locally electroplating a nickel layer on the soldering pin 322 surface. The coating has a hardness ≥HV500, excellent wear resistance, and good corrosion resistance, making it suitable for capacitor products used in harsh environments such as humid and corrosive conditions. The partial tin plating process involves locally electroplating a pure tin or tin-lead alloy layer on the soldering pin 322 surface. This coating offers optimal solderability, achieving good wetting without additional flux during brazing, and exhibits high plating smoothness, making it suitable for automated high-speed brazing production lines and reducing welding defect rates.

[0027] The above-mentioned local coating process can be used alone or in combination depending on the product application scenario (such as first locally electroplating nickel and then electroplating tin to form a nickel-tin composite coating) to further improve the overall performance of the coating layer.

[0028] Furthermore, the number of locally coated surfaces of the welding pin 322 is at least one surface.

[0029] In specific examples, the non-pure copper conductive material is one of pure aluminum, aluminum alloy, or steel. Pure aluminum has a density only one-third that of copper, resulting in reduced weight for the same volume and a material cost only about 30% of copper. It boasts excellent conductivity and good stamping performance, making it suitable as the base material for the internal electrode 320 under normal operating conditions. This significantly reduces material costs and overall product weight while maintaining conductivity. Aluminum alloys are made by adding alloying elements such as magnesium and silicon to pure aluminum, increasing its strength and resistance to deformation. It retains the low density and low cost advantages of pure aluminum, making it suitable for high-current, high-mechanical-stress applications and preventing deformation and failure of the internal electrode 320 during assembly or use. Steel has the highest structural strength, excellent impact and vibration resistance, and a material cost only about 20% of copper, resulting in the most significant cost reduction. It is suitable for applications with high cost control requirements and moderate current. When used in conjunction with cold-spray copper powder coating, it achieves a good balance between weldability and structural strength. All three types of materials do not require overall surface treatment; only local coating of the welding pin 322 is needed to meet the brazing requirements.

[0030] In addition, the main body 321 of the internal electrode 320 has a perforated hole 324 corresponding to the position of the welding pin 322. The perforated hole 324 provides clearance for the welding pin 322, reducing the obstruction of the capacitor core 2 by the internal electrode 320, and also increases the heat dissipation area of ​​the internal electrode 320. Combined with the heat conduction path of the filler 4, it can effectively reduce the operating temperature of the capacitor core 2. The perforated hole 321 is rectangular in shape and its size is slightly larger than the width of the welding pin 322.

[0031] In this embodiment, the welding needle 322 is straight, which facilitates stamping and welding positioning.

[0032] In terms of connection methods, the external electrode 310 and the internal electrode 320 can be fixedly connected by laser welding, ultrasonic welding, molecular diffusion welding, brazing, or mechanical riveting: laser welding or ultrasonic welding is suitable for automated mass production, with high welding efficiency and strong connection reliability; mechanical riveting is suitable for on-site repair or small-batch customization, and facilitates later disassembly and maintenance. The welding pin 322 is connected to the capacitor core 2 by brazing. The solderable coating layer 323 allows the molten tin to more fully wet the gold-plated layer of the core and the welding pin 322, enhancing the reliability of the electrical connection.

[0033] In addition, the electrode assembly 3 includes independent positive electrode units and negative electrode units. The positive electrode units and negative electrode units are symmetrically arranged. That is, the positive electrode unit includes a positive external electrode 310a and a positive internal electrode 320a, and the negative electrode unit includes a negative external electrode 310b and a negative internal electrode 320b. The positive internal electrode 320a and the negative internal electrode 320b are made of aluminum or aluminum alloy and are symmetrically distributed on both sides of the capacitor core 2. The welding pins of the positive internal electrode 320a and the negative internal electrode 320b are respectively brazed to the positive and negative end electrodes of the capacitor core 2 to realize bidirectional conduction of electricity. The positive external electrode 310a and the negative external electrode 310b are made of copper or copper alloy and are fixedly connected to the positive internal electrode 320a and the negative internal electrode 320b respectively, serving as the connection ports between the capacitor and the external circuit.

[0034] In a specific example, after the electrode assembly 3 and the capacitor core 2 are assembled into a single capacitor, they are placed in the receiving cavity 110. Then, the filler 4 is filled into the receiving cavity 110 and cured within it. The filler 4 can be a potting material that combines insulation and thermal conductivity, such as epoxy resin, polyurethane, or silicone resin. Before curing, the filler 4, in liquid form, fully penetrates into the gaps between the capacitor cores 2, the structural gaps of the electrode assembly 3, and the gaps between the capacitor cores 2 and the inner wall of the housing 1. After curing, it forms a dense, integrated protective structure. On the one hand, the filler 4 firmly bonds the capacitor core 2, electrode assembly 3 and shell 1 into a whole, which greatly improves the capacitor's vibration and shock resistance performance and avoids connection failure due to structural loosening under transportation or high-frequency vibration conditions (such as new energy vehicles and rail transit scenarios). On the other hand, the thermal conductivity of the filler 4 can quickly conduct the heat generated by the capacitor core 2 during operation to the shell 1. Combined with the hollow hole design of the internal electrode 320, an efficient heat dissipation path is formed from core to filler to shell, which reduces the operating temperature of the capacitor and effectively extends its service life.

[0035] According to this embodiment, the following effects are achieved: there is no need to set up an additional independent adapter electrode; the welding pin 322 is directly integrated on the internal electrode 320 and locally coated, eliminating the need for adapter electrode parts and their assembly process, thus simplifying the production process; the overlap contact resistance between the adapter electrode and the internal electrode 320 is avoided, improving connection reliability and increasing power conduction efficiency; the internal electrode 320 can be made of aluminum material as a whole, with coating only applied to the welding pin 322, greatly reducing the amount of copper used and significantly reducing the overall material cost.

[0036] Example 2 The structure and principle of this embodiment are largely the same as those of Embodiment 1, and the similarities will not be described in detail here. The differences are as follows: Combination Figure 4As shown, the external electrode 310 and the internal electrode 320 are integrally formed structures, and the whole is made of non-pure copper conductive materials, such as aluminum alloy materials, through precision stamping process to form one piece, without the need for additional welding or connection processes, which further simplifies the production process, avoids contact resistance at the connection part of the external electrode 310 and the internal electrode 320, and greatly improves the power conduction efficiency.

[0037] In this embodiment, the solder pins 322 of the internal electrode 320 are still coated with a solderable coating layer through a local coating process. For example, a local cold spray tin powder process is used to form a solderable coating layer 323 with a coating thickness of 0.03 mm to ensure the reliability of the brazing with the capacitor core 2.

[0038] The thin-film capacitor of this embodiment simplifies the production process compared to Embodiment 1 by eliminating the connection process between the external and internal electrodes, thereby improving production efficiency and reducing product defect rate. The electrodes have no connection interface, resulting in higher structural strength and better vibration and impact resistance.

[0039] Example 3 The structure and principle of this embodiment are largely the same as those of Embodiment 1, and the similarities will not be described in detail here. The differences are as follows: Combination Figure 5 As shown, the internal electrode 320 is made of copper, and the welding pin 322 is directly connected to the capacitor core 2 by brazing, resulting in excellent connection reliability. The external electrode 310 is also made of non-pure copper conductive materials such as aluminum alloy, and is fixedly connected to the internal electrode 320 by ultrasonic welding. The exposed terminal surface of the external electrode 310 is coated with a conductive protective layer 311 with a thickness of 0.04 mm by a local coating process (such as local electroplating tin), which can prevent oxidation and corrosion of the aluminum alloy substrate, thereby reducing capacitance and contact resistance.

[0040] In this embodiment, the internal electrode 320 is made of highly conductive copper to ensure high current conduction performance, while the external electrode 310 is made of aluminum alloy to reduce costs and lighten weight. The overall material cost is lower than that of the all-copper electrode solution, and the weight is also reduced, thus taking into account both performance and cost advantages.

[0041] The thin-film capacitor in this embodiment, through the combination of inner copper and outer aluminum electrode materials and a partial coating process for exposed terminals, achieves cost optimization while maintaining excellent conductivity. It is particularly suitable for applications with high requirements for current conduction efficiency, such as photovoltaic grid-connected inverters and industrial power supplies. Example 4 The structure and principle of this embodiment are largely the same as those of Embodiment 2. The similarities will not be described in detail here. The differences are as follows: Combination Figure 6As shown, the electrode assembly 3 is integrally stamped from 304 stainless steel. The surface of the welding pin 322 of the internal electrode 320 is coated with a solderable coating layer 323 with a thickness of 0.04 mm through a local coating process (such as cold spray copper powder process), which has excellent solderability. The exposed terminal surface of the external electrode 310 is coated with a conductive protective layer 311 with a thickness of 0.06 mm through a local coating process (such as electroplating silver process), which has excellent oxidation resistance. This can reduce capacitance and contact resistance.

[0042] The thin-film capacitor in this embodiment uses stainless steel electrode material throughout, which reduces material costs compared to pure copper solutions. It also has excellent structural strength, corrosion resistance, and wide temperature adaptability, making it particularly suitable for large-scale applications such as energy storage power stations and rail transportation where cost sensitivity and environmental adaptability are high requirements.

[0043] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," 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 element 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.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0045] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0047] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring 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. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0048] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A thin-film capacitor, characterized in that, include: The shell has a receiving cavity; The capacitor core is disposed within the receiving cavity; An electrode assembly includes an external electrode and an internal electrode. The internal electrode is made of a non-pure copper conductive material and is disposed within the receiving cavity. The internal electrode includes a main body and a welding pin integrated on the main body. The surface of the welding pin is coated with a solderable coating layer through a local coating process. The welding pin is brazed to the capacitor core through the solderable coating layer. The main body and the internal electrode are overlapped and fixed to realize the power conduction between the capacitor core and the internal electrode. The external electrode is fixedly connected to the internal electrode or integrally formed to lead out the power of the capacitor core.

2. A thin-film capacitor, characterized in that, include: The shell has a receiving cavity; The capacitor core is disposed within the receiving cavity; An electrode assembly includes an external electrode and an internal electrode; the internal electrode is disposed within the receiving cavity; the internal electrode includes a main body and a welding pin integrated on the main body, the welding pin being brazed to the capacitor core, and the main body being overlapped and fixed to the internal electrode to achieve power conduction between the capacitor core and the internal electrode; the external electrode is fixedly connected to or integrally formed with the internal electrode to lead out the power of the capacitor core, the external electrode is made of a non-pure copper conductive material, and the exposed terminal surface of the external electrode is formed with a conductive protective layer through a local coating process to reduce contact resistance.

3. The thin-film capacitor as described in claim 1, characterized in that, The external electrode is made of a non-pure copper conductive material, and the exposed terminal surface of the external electrode is coated with a conductive protective layer to reduce contact resistance.

4. The film capacitor according to any one of claims 1-3, characterized in that, The non-pure copper conductive material is one of pure aluminum, aluminum alloy, or steel.

5. The film capacitor as described in any one of claims 1-3, characterized in that, The local coating process is at least one of the following: cold spraying copper powder, cold spraying tin powder, local copper plating, local nickel plating, local tin plating, and nickel sheet bonding.

6. The thin-film capacitor as claimed in claim 1, characterized in that, The number of locally coated surfaces of the welding needle is at least one surface.

7. The thin-film capacitor as claimed in claim 1, characterized in that, The welding needle and the main body are integrally stamped and formed.

8. The thin-film capacitor as claimed in claim 1 or 2, characterized in that, The external electrode and the internal electrode are fixedly connected by laser welding, ultrasonic welding, molecular diffusion welding, brazing or mechanical riveting, or the external electrode and the internal electrode are integrally stamped.

9. The thin-film capacitor as claimed in claim 1, characterized in that, The thickness of the solderable coating is 0.001mm-0.6mm.

10. The thin-film capacitor as claimed in claim 2 or 3, characterized in that, The thickness of the conductive protective layer is 0.001mm-0.6mm.

Images