Novel surface-mounted thin-film capacitor
By employing L-shaped copper foil leads and a comb-shaped conductive structure in film capacitors, the problem of unstable connections in traditional film capacitors is solved, achieving higher conductivity and stability, and facilitating their use on circuit boards.
Patent Information
- Application Number
- CN202620048600.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-15
- Publication Date
- 2026-02-17
- Estimated Expiration
- 2036-01-15
AI Technical Summary
The connection between the metal leads of traditional film capacitors and the stacked capacitor core is prone to overheating and metal migration, resulting in poor conductivity and shortened service life.
It adopts L-shaped copper foil leads and comb-shaped conductive structure. By staggered and alternately stacked metal film layers to form gaps, and comb-shaped conductive structure is set in the gaps. The comb teeth form a large-area stable electrical connection with the metal layer. Combined with conductive paste coating and plating, conductivity and stability are enhanced.
It significantly reduces contact resistance, improves conductivity and stability, is suitable for high-current applications, and is easy to mount on circuit boards.
Smart Images
Figure CN223927215U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a thin film capacitor, and more particularly to a novel surface-mount thin film capacitor. Background Technology
[0002] The capacitor body of a traditional film capacitor is made of a metal film coated with a metal layer, which is wound into a dense metal film roll. The leads of the film capacitor are generally strip metal leads. Two strip metal leads are inserted into the two ends of the metal film roll and soldered as necessary to achieve electrical connection between the capacitor body and the strip metal leads.
[0003] With improvements in capacitor manufacturing processes, laminated capacitor cores have emerged. These are typically composed of multiple metal film layers coated with metal (one side of which is coated with a metal layer), stacked together. Two strip-shaped metal leads are directly soldered to the two end faces of the laminated capacitor body, usually using tin soldering. However, since each metal film layer is only exposed a few micrometers on the end faces, the electrical connection between the strip-shaped metal leads and the laminated capacitor core depends on the solder at the solder joints. This can easily lead to localized overheating, metal migration, and poor conductivity between the metal leads and the metal film layers, thus significantly shortening the lifespan of the film capacitor. Utility Model Content
[0004] The problem to be solved by this utility model is to provide a new type of surface-mount film capacitor. This new type of surface-mount film capacitor has better conductivity and higher stability in its metal leads and can be mounted on a circuit board.
[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:
[0006] A novel surface-mount thin-film capacitor includes a stacked capacitor core and left and right leads disposed on the left and right end faces of the stacked capacitor core. The stacked capacitor core is characterized by being composed of multiple alternating layers of first and second metal films; on the left end face, the first metal film is exposed outside the second metal film, forming a first gap between adjacent first metal film layers, and the left end face is provided with a vertically extending first comb-shaped conductive structure, with each tooth of the first comb-shaped conductive structure extending into the corresponding first gap; on the right end face... At the end face, the second metal film layer is exposed outside the first metal film layer, and a second gap is formed between two adjacent second metal film layers. The right end face is provided with a second comb-shaped conductive structure extending vertically, and each tooth of the second comb-shaped conductive structure extends into the corresponding second gap. The left and right pins are both L-shaped copper foil pins, which include vertical copper foils and horizontal copper foils. The two vertical copper foils are respectively welded to the back of the first and second comb-shaped conductive structures. The lower end of the vertical copper foil is exposed below the lower end face of the film capacitor body.
[0007] Typically, the aforementioned film capacitor has an outer casing, with the horizontal copper foil sheets of the left and right leads exposed below the bottom of the casing.
[0008] The copper foil thickness of the L-shaped copper foil pins mentioned above is generally 17.5μm-105μm.
[0009] Because L-shaped copper foil leads have excellent thermal conductivity and a larger contact area than traditional metal leads, the overall contact resistance is significantly reduced and the conductivity is enhanced. The first and second metal film layers of the stacked capacitor core are alternately stacked in a staggered manner to form first and second gaps. Based on this, first and second comb-shaped conductive structures are set. The teeth of the first and second comb-shaped conductive structures extend into the first and second gaps respectively, forming a large-area stable electrical connection with the corresponding metal layers. Furthermore, the backs of the first and second comb-shaped conductive structures are used for soldering the L-shaped copper foil leads, resulting in higher stability due to the large-area soldering. Moreover, because L-shaped copper foil leads are used, the horizontal copper foil of the left lead and the right lead are on the same plane, facilitating mounting on the circuit board.
[0010] In a preferred embodiment of this utility model, both the first comb-shaped conductive structure and the second comb-shaped conductive structure are formed by coating and curing a conductive paste, and the comb teeth are formed by the conductive paste penetrating into the first gap and the second gap. The conductive paste is generally a conductive paste containing silver particles.
[0011] As a preferred embodiment of this invention, the surface of the L-shaped copper foil pin is plated with a coating. This coating enhances the corrosion resistance of the L-shaped copper foil pin and extends its service life in harsh environments. The dimensions (length and width) of the L-shaped copper foil pin can be flexibly customized according to actual needs, increasing the current path and meeting the requirements of high-current applications.
[0012] As a further preferred embodiment of this invention, the plating layer is an anti-oxidation layer. This anti-oxidation layer forms a dense protective film on the surface of the L-shaped copper foil leads, reducing the contact between moisture and the copper foil, and effectively preventing corrosion of the L-shaped copper foil leads in humid environments.
[0013] As a further preferred embodiment of this utility model, the material of the antioxidant layer is tin, silver, nickel or gold.
[0014] As a preferred embodiment of the present invention, both the first metal film layer and the second metal film layer include a plastic film layer and a metal coating applied to one side of the plastic film layer.
[0015] As a further preferred embodiment of this utility model, the metal coating is made of aluminum, silver or nickel.
[0016] As a preferred embodiment of this utility model, the welding is ultrasonic welding or laser welding.
[0017] Compared with the prior art, this utility model has the following advantages:
[0018] This new type of surface-mount film capacitor significantly increases the contact area between the leads and the metal coating of the stacked capacitor core by optimizing the design of the stacked capacitor core, setting a first comb-shaped conductive structure and a second comb-shaped conductive structure, and using L-shaped copper foil leads. This reduces the overall contact resistance, improves stability, and allows it to be mounted on a circuit board. Attached Figure Description
[0019] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model;
[0020] Figure 2 This is a left view of an embodiment of the present invention (outer shell omitted). Detailed Implementation
[0021] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0022] like Figure 1-2 As shown, the novel surface-mount thin-film capacitor in this embodiment includes a stacked capacitor core 1 and left leads 2 and right leads 3 disposed on the left end face 11 and right end face 12 of the stacked capacitor core 1. The stacked capacitor core 1 is formed by alternatingly stacking multiple first metal film layers 13 and second metal film layers 14. At the left end face 11, the first metal film layer 13 is exposed outside the second metal film layer 14, and a first gap 15 is formed between two adjacent first metal film layers 13. The left end face 11 is provided with a first comb-shaped conductive structure 16 extending vertically, and each comb tooth 161 of the first comb-shaped conductive structure 16 extends into the corresponding first gap 15. At the right end face 12, ... The second metal film layer 14 is exposed outside the first metal film layer 13. A second gap 17 is formed between two adjacent second metal film layers 14. The right end face 12 is provided with a second comb-shaped conductive structure 18 extending vertically. Each comb tooth 161 of the second comb-shaped conductive structure 18 extends into the corresponding second gap 17. The left pin 2 and the right pin 3 are both L-shaped copper foil pins 21. The L-shaped copper foil pins 21 include vertical copper foil 211 and horizontal copper foil 212. The two vertical copper foils 211 are respectively welded to the comb backs 162 of the first comb-shaped conductive structure 16 and the second comb-shaped conductive structure 18. The lower end of the vertical copper foil 211 is exposed below the lower end face of the film capacitor body.
[0023] Typically, the aforementioned thin-film capacitor has an outer casing 4 on its outer side, and the horizontal copper foil 212 of the left lead 2 and the right lead 3 are exposed below the bottom of the casing 4.
[0024] The thickness of the copper foil of the L-shaped copper foil pin 21 is generally 17.5μm-105μm.
[0025] Because the L-shaped copper foil pins 21 have excellent thermal conductivity and a larger contact area than traditional metal pins, the overall contact resistance is significantly reduced and the conductivity is enhanced. The first metal film layer 13 and the second metal film layer 14 of the stacked capacitor core 1 are alternately stacked in a staggered manner to form a first gap 15 and a second gap 17. Based on this, a first comb-shaped conductive structure 16 and a second comb-shaped conductive structure 18 are provided. The comb teeth 161 of the first comb-shaped conductive structure 16 and the second comb-shaped conductive structure 18 extend into the first gap 15 and the second gap 17 respectively, forming a large-area stable electrical connection with the corresponding metal layers. Furthermore, the back of the comb 162 of the first comb-shaped conductive structure 16 and the second comb-shaped conductive structure 18 is used for soldering the L-shaped copper foil pins 21. The large-area soldering results in higher stability. Moreover, because the L-shaped copper foil pins 21 are used, the horizontal copper foil 212 of the left pin 2 and the horizontal copper foil 212 of the right pin 3 are on the same plane, facilitating mounting on the circuit board.
[0026] Both the first comb-shaped conductive structure 16 and the second comb-shaped conductive structure 18 are formed by coating and curing conductive paste. The comb teeth 161 are formed by the conductive paste penetrating into the first gap 15 and the second gap 17. The conductive paste generally uses a conductive paste containing silver particles.
[0027] The surface of the L-shaped copper foil pin 21 is plated with a plating layer 22. This plating layer 22 enhances the corrosion resistance of the L-shaped copper foil pin 21 and extends its service life in harsh environments. The dimensions (length and width) of the L-shaped copper foil pin 21 can be flexibly customized according to actual needs, increasing the current path and meeting the requirements of high-current applications.
[0028] The plating layer 22 is an anti-oxidation layer. The aforementioned anti-oxidation layer can form a dense protective film on the surface of the L-shaped copper foil pin 21, reducing the contact between moisture and copper foil, and effectively preventing the corrosion of the L-shaped copper foil pin 21 in a humid environment.
[0029] The anti-oxidation layer is made of silver.
[0030] Both the first metal film layer 13 and the second metal film layer 14 include a plastic film layer 131 and a metal coating 132 applied to one side of the plastic film layer 131.
[0031] All materials used in the 132 metal coating are silver.
[0032] The welding was ultrasonic welding.
[0033] Furthermore, it should be noted that the names of the various parts of the specific embodiments described in this specification may differ. All equivalent or simple variations made to the structure, features, and principles described in this utility model patent concept are included within the protection scope of this utility model patent. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the structure of this utility model or exceed the scope defined in these claims, they should all fall within the protection scope of this utility model.
Claims
1. A novel surface-mount thin-film capacitor, comprising a stacked capacitor core and left and right leads disposed on the left and right end faces of the stacked capacitor core, characterized in that: The stacked capacitor core is composed of multiple alternating layers of first and second metal films. At the left end face, the first metal film is exposed outside the second metal film, forming a first gap between adjacent first metal film layers. The left end face also features a vertically extending first comb-shaped conductive structure, with each tooth of the first comb-shaped conductive structure extending into the corresponding first gap. At the right end face, the second metal film is exposed outside the first metal film, forming a second gap between adjacent second metal film layers. The right end face also features a vertically extending second comb-shaped conductive structure, with each tooth of the second comb-shaped conductive structure extending into the corresponding second gap. Both the left and right leads are L-shaped copper foil leads, comprising vertical and horizontal copper foil pieces. The two vertical copper foil pieces are respectively soldered to the backs of the first and second comb-shaped conductive structures. The lower ends of the vertical copper foil pieces are exposed below the lower end face of the thin-film capacitor body.
2. The novel surface-mount film capacitor according to claim 1, characterized in that: Both the first and second comb-shaped conductive structures are formed by coating and curing conductive paste, and the comb teeth are formed by the conductive paste penetrating into the first and second gaps.
3. The novel surface-mount film capacitor according to claim 1, characterized in that: The surface of the L-shaped copper foil pins is plated with a coating.
4. The novel surface-mount film capacitor according to claim 3, characterized in that: The coating is an antioxidant layer.
5. The novel surface-mount film capacitor according to claim 4, characterized in that: The material of the antioxidant layer is tin, silver, nickel or gold.
6. The novel surface-mount film capacitor according to claim 1, characterized in that: Both the first metal film layer and the second metal film layer include a plastic film layer and a metal coating applied to one side of the plastic film layer.
7. The novel surface-mount film capacitor according to claim 6, characterized in that: The metal coatings are all made of aluminum, silver, or nickel.
8. The novel surface-mount film capacitor according to claim 1, characterized in that: The welding is ultrasonic welding or laser welding.