Capacitor and preparation method thereof

Abstract

The invention discloses a capacitor and a preparation method of the capacitor. The capacitor comprises a substrate and at least one conductive structure, the at least one conductive structure is stacked on the substrate in the thickness direction of the substrate, each conductive structure comprises a single-chip core and a conductive foil, the single-chip core comprises a negative electrode area, a middle area and a positive electrode piece which are sequentially connected in the first direction, the middle area is coated with an insulating layer, and the conductive foil is arranged in the middle area. The conductive foil comprises a foil body and a negative pole piece which are connected along a first direction; the foil body is laminated and attached to the negative electrode area, one part of the negative electrode piece is laminated and attached to the insulating layer of the middle area, the other part of the negative electrode piece and the positive electrode piece are distributed in a spaced mode in the second direction, and the positive electrode piece and the negative electrode piece are electrically connected with the substrate. According to the capacitor disclosed by the invention, the conductive foil is connected with the single core, so that the thickness of the capacitor is reduced, the equivalent series resistance of the chip-type laminated solid aluminum electrolytic capacitor is reduced, and the problem that current and heat are not uniformly distributed in the capacitor is also solved.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitors, and in particular to a capacitor and a method for preparing the capacitor. Background Art

[0002] Chip solid aluminum electrolytic capacitors are mainly used in notebooks, tablets and other fields. With the continuous development of technology, the basic characteristics of products in this field are becoming more and more demanding.

[0003] For example, traditional chip-type laminated solid aluminum electrolytic capacitors are thicker and have smaller capacity due to the use of metal leads and bending and coating treatment, as well as at least two layers of different types of conductive coatings on the outside of the single-chip core. In addition, it is difficult to keep the thickness of the at least two layers of different types of conductive coatings on the single-chip core consistent, and gaps are easily generated in the overlapping areas, which will cause uneven distribution of current and heat inside the capacitor, and the equivalent series resistance is large, which cannot meet current needs. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a capacitor, wherein the conductive structure of the capacitor is achieved by connecting a conductive foil to a monolithic core, and the outer surface of the monolithic core does not need to be provided with a conductive coating, and the connection with the monolithic core is achieved through the conductive foil, which can reduce the thickness of the chip-type laminated solid aluminum electrolytic capacitor, reduce the equivalent series resistance of the chip-type laminated solid aluminum electrolytic capacitor, and also solve the problem of uneven distribution of current and heat inside the capacitor.

[0005] A capacitor according to an embodiment of the present invention comprises: a substrate and at least one conductive structure; at least one of the conductive structures is stacked on the substrate along the thickness direction of the substrate, each of the conductive structures comprises a single-piece core and a conductive foil, the single-piece core comprises a negative electrode region, a middle region and a positive electrode plate connected in sequence along a first direction, the middle region is coated with an insulating layer, and the conductive foil comprises a foil body and a negative electrode plate connected along the first direction; wherein the foil body is stacked and bonded to the negative electrode region, a portion of the negative electrode plate is stacked and bonded to the insulating layer of the middle region and the other portion is spaced apart and distributed from the positive electrode plate along the second direction, and the positive electrode plate and the negative electrode plate are electrically connected to the substrate respectively.

[0006] According to the capacitor of the embodiment of the present invention, the embodiment of the present invention does not need to apply a conductive layer on the outside of the monolithic core, and a conductive foil is used alone to connect to the monolithic core. The conductive foil is located on one side of the monolithic core and is connected to the monolithic core, which is equivalent to reducing the coating thickness on the other side of the original monolithic core, and the positive pole piece and the negative pole piece do not need to be bent by separately arranged metal leads, and the metal leads will occupy the thickness inside the capacitor, resulting in a thicker thickness; the embodiment of the present invention, especially when multiple conductive structures are stacked, can reduce the thickness of the chip-type laminated solid aluminum electrolytic capacitor, reduce the equivalent series resistance of the chip-type laminated solid aluminum electrolytic capacitor, and also reduce the problem of uneven distribution of current and heat inside the capacitor caused by gaps between multi-layer coatings or uneven thickness of the coatings, and the multi-layer coating contains insulating materials, which will increase the resistance when two adjacent conductive structures are connected, that is, the structure in the embodiment of the present invention can reduce the equivalent series resistance.

[0007] According to the capacitor of the embodiment of the present invention, there are a plurality of the conductive structures, and when the plurality of the conductive structures are stacked and connected, each of the conductive foils is located between two adjacent single-piece cores.

[0008] According to the capacitor of the embodiment of the present invention, the negative electrode region of the single-piece core and the substrate, as well as the foil body and the negative electrode region of the single-piece core are bonded by polymer dispersion, and the positive electrode sheet and the substrate, as well as adjacent positive electrode sheets are bonded by welding.

[0009] According to the capacitor of the embodiment of the present invention, a positive electrode pad, a negative electrode pad and a negative electrode bonding area are provided on the substrate; the positive electrode pad and the negative electrode pad are distributed on the substrate at intervals along the second direction, the negative electrode bonding area and the negative electrode pad are distributed on the substrate along the first direction, and the negative electrode bonding area and the negative electrode pad are electrically connected through a transition area, the positive electrode plate is electrically connected to the positive electrode pad, and the negative electrode plate is at least partially electrically connected to the negative electrode pad, the middle area of ​​the single-piece core is arranged in the transition area, and the negative electrode area of ​​the single-piece core is connected to the negative electrode bonding area of ​​the substrate.

[0010] According to the capacitor of the embodiment of the present invention, a positive pin and a negative pin are provided on the back side of the substrate, and the positive pin and the negative pin are spaced apart along the first direction; the positive pin is electrically connected to a current limiting conductive plate, the current limiting conductive plate is provided with a first via hole, and the current limiting conductive plate is electrically connected to the positive electrode pad by passing a wire through the first via hole, the negative pin is provided with a second via hole, and the negative pin is electrically connected to the negative electrode bonding area by passing a wire through the second via hole, the positive pin is used to connect one end of an external circuit, and the negative pin is connected to the other end of the external circuit, and the current limiting conductive plate is suitable for disconnecting the capacitor from the external circuit when the first via hole and the positive electrode pad are fused.

[0011] According to the capacitor of an embodiment of the present invention, the current limiting conductive plate includes a first section, a second section and a third section that are bent and connected, one end of the first section is connected to the positive pin and the other end extends in a direction away from the positive pin to connect to the second section, the second section is located on one side of the positive pin in the first direction, the third section is connected to the second section and extends in a direction close to the positive pin and is staggered with the positive pin, and the first via is located at one end of the third section away from the second section.

[0012] An embodiment of the present invention also discloses a method for preparing a capacitor, which is used to prepare the above-mentioned capacitor, and includes the following steps: preparing the single-piece core, and dividing the single-piece core into a negative electrode region, a middle region and a positive electrode plate; preparing the conductive foil, and pre-plating a carbon layer on the outer surface of a conductive metal body to form the conductive foil; installing the conductive structure, installing the single-piece core on the substrate, and stacking the conductive foil and connecting it to the single-piece core, and the negative electrode plate of the conductive foil is connected to the substrate.

[0013] According to the preparation method of the capacitor of the embodiment of the present invention, a conductive foil is formed by setting a carbon layer on a conductive metal body, so that there is no need to coat multiple conductive layers on the outer surface of the monolithic core. When the monolithic core is coated, coatings are set on both sides. When a conductive structure is set, compared with the original monolithic core coating, it is equivalent to reducing the coating thickness on one side of the monolithic core as a whole. Similarly, since there is no need to set a metal lead on one side of the monolithic core in the thickness direction, the thickness of the capacitor can be reduced; and when multiple conductive structures are set, two monolithic cores can share one conductive foil, which reduces the thickness of the entire capacitor. At the same time, the problem of excessive resistance caused by gaps between multiple coatings is also reduced. Compared with the multiple coatings on the outer surface of the monolithic core, the design of the conductive foil reduces the uneven thickness of the coating, so that the current and heat are distributed more evenly inside the capacitor.

[0014] According to the method for preparing a capacitor of an embodiment of the present invention, the preparation of the monolithic core comprises: cutting, selecting an anode foil and cutting the anode foil into a plurality of monomers of a desired size; assembling, arranging the plurality of monomers on a process iron bar; coating with glue, coating the arranged plurality of monomers with insulating glue lines to isolate the negative electrode region and the positive electrode sheet; forming, repairing the oxide layers of the plurality of monomers; and coating, forming a conductive polymer layer on the surface of the negative electrode region to form the monolithic core.

[0015] According to the preparation method of the capacitor of the embodiment of the present invention, the installation of the conductive structure includes: dividing the main substrate into multiple installation areas, the multiple installation areas are arranged horizontally into multiple rows and vertically into multiple columns, and the conductive structure is installed in each installation area; the conductive structure of each installation area is plastic-sealed; the positive pole pieces and the negative pole pieces of the multiple capacitors are located on the same side of the first direction of the main substrate; the main substrate is divided into multiple sub-substrates and corresponding multiple capacitors along the second direction; the two end surfaces of the corresponding multiple capacitors on each sub-substrate are electroplated along the first direction; the multiple capacitors corresponding to each sub-substrate are cut into single capacitors along the first direction; the qualification of the products is tested and unqualified products are excluded.

[0016] According to the method for preparing a capacitor in an embodiment of the present invention, the qualification test of the product includes: performing aging treatment on a single capacitor; reflow soldering test, applying reflow soldering high temperature to the capacitor; and test sorting, performing parameter testing on the capacitor to exclude capacitors with unqualified parameters.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 is a schematic structural diagram of a conductive foil of a capacitor according to an embodiment of the present invention;

[0020] Figure 2 is a structural schematic diagram of a monolithic core of a capacitor according to an embodiment of the present invention;

[0021] Figure 3 is a cross-sectional schematic diagram of a monolithic core of a capacitor according to an embodiment of the present invention;

[0022] Figure 4 is a front schematic diagram of a substrate of a capacitor according to an embodiment of the present invention;

[0023] Figure 5 is a schematic diagram of the back side of a substrate of a capacitor according to an embodiment of the present invention;

[0024] Figure 6 It is a schematic diagram of the structure in which a single-chip core and a conductive foil are installed on a substrate according to an embodiment of the present invention;

[0025] Figure 7 It is a schematic diagram of the structure of a single-chip core and a conductive foil after being installed on a substrate and plastic-sealed according to an embodiment of the present invention;

[0026] Figure 8 It is a schematic diagram of the main process of the method for preparing a capacitor according to an embodiment of the present invention;

[0027] Fig. 9 It is a schematic diagram of the process of preparing a single-chip core according to an embodiment of the present invention;

[0028] Fig.10 is a schematic diagram of a process of installing a conductive structure according to an embodiment of the present invention;

[0029] Fig.11 This is a schematic diagram of a process for testing product eligibility according to an embodiment of the present invention;

[0030] Fig.12 1 is a schematic diagram of the overall process of a method for preparing a capacitor according to an embodiment of the present invention;

[0031] Fig.13 It is a schematic diagram of an array structure in which a single core and a conductive foil are installed in multiple installation areas on a substrate of a capacitor according to an embodiment of the present invention;

[0032] Fig.14 It is a structural schematic diagram of a capacitor according to an embodiment of the present invention, in which a substrate is divided into a plurality of sub-substrates along a second direction.

[0033] Reference numerals:

[0034] Capacitor 100,

[0035] Conductive foil 1, foil body 11, negative electrode piece 12, single-piece core 2, positive electrode piece 21, middle area 22, negative area 23, metal core 231, oxide layer 232, conductive polymer layer 233, substrate 3, first via 30, positive electrode pin 31, current limiting conductive plate 32, first section 321, second section 322, third section 323, positive electrode pad 33, board body 34, second via 35, negative electrode pin 36, negative electrode fitting area 37, transition area 38, negative electrode pad 39, epoxy resin shell 4, positive electrode electroplating end face 41, negative electrode electroplating end face 42, installation area 301. DETAILED DESCRIPTION

[0036] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] Reference below Figure 1-Figure 14 A capacitor 100 and a method for preparing the capacitor 100 according to an embodiment of the present invention are described. The conductive structure of the capacitor 100 is achieved by connecting a conductive foil 1 to a single-piece core 2. The outer surface of the single-piece core 2 does not need to be provided with a conductive coating. The positive pole piece 21 and the negative pole piece 12 do not occupy space on the thickness of the capacitor 100. The connection with the single-piece core 2 is achieved by the conductive foil 1, so that the thickness of the chip-type laminated solid aluminum electrolytic capacitor 100 can be reduced. In particular, when multiple conductive structures are stacked, two single-piece cores 2 share a conductive foil 1, which effectively reduces the thickness of the capacitor 100 and reduces the equivalent series resistance of the chip-type laminated solid aluminum electrolytic capacitor. At the same time, the problem of uneven distribution of current and heat inside the capacitor 100 is also solved.

[0040] like Figure 1-14 As shown, the capacitor 100 in the embodiment of the present invention includes: a substrate 3 and at least one conductive structure.

[0041] Among them, at least one conductive structure is superimposed on the substrate 3 along the thickness direction of the substrate 3, and each conductive structure includes a single core 2 and a conductive foil 1. The single core 2 includes a negative electrode region 23, an intermediate region 22 and a positive electrode plate 21 connected in sequence along a first direction, and the intermediate region 22 is covered with an insulating layer. The conductive foil 1 includes a foil body 11 and a negative electrode plate 12 connected along the first direction; wherein the foil body 11 is superimposed and bonded to the negative electrode region 23, a part of the negative electrode plate 12 is superimposed and bonded to the insulating layer of the intermediate region 22, and the other part is spaced apart and distributed from the positive electrode plate 21 along the second direction, and the positive electrode plate 21 and the negative electrode plate 12 are respectively electrically connected to the substrate 3.

[0042] In practice, the single-piece core 2 includes a metal core 231 in the middle and an outer oxide layer 232, and the oxide layer 232 outside the negative electrode region 23 is usually also coated with a conductive polymer layer 233, and the other part coated with the oxide layer 232 can be used as the positive electrode plate 21. The insulating layer of the middle region 22 separates the negative electrode region 23 and the positive electrode plate 21 to prevent the capacitor 100 from being damaged by the conductive polymer layer 233 due to the tensile stress and bending stress generated at the connection between the positive electrode plate 21 and the negative electrode region 23 during welding, thereby causing technical problems such as a decrease in the qualified rate and an increase in the current.

[0043] That is, the conductive polymer layer 233 forms one plate of the capacitor 100, and the oxide layer 232 serves as an intermediate dielectric. Meanwhile, the metal core 231 serves as another plate of the capacitor 100. When a voltage is applied between the two plates of the capacitor 100, the capacitor 100 will store charge to realize the function of the capacitor 100.

[0044] However, in the prior art, in order to enhance the conductivity and stability of the monolithic core 2, a silver layer and a carbon layer are impregnated, coated or printed on the outer surface of the monolithic core 2, and in order to achieve the connection of multiple monolithic cores 2, a silver layer and a carbon layer are impregnated, coated or printed on both sides of the monolithic core 2 in the thickness direction; while in the embodiment of the present invention, the negative electrode region 23 of the monolithic core 2 has only a conductive polymer layer 233 on the outside, and there is no need to impregnate, coat or print a carbon layer and a silver layer. The conductive foil 1 is directly used to connect the monolithic core 2, which can reduce the thickness of the monolithic core 2 and the thickness of the capacitor 100. Assuming that the thickness of the carbon layer and the silver layer on one side of the monolithic core 2 in the prior art is the same as the thickness of the conductive foil 1, then in the present invention, when the monolithic core 2 and the conductive foil 1 are connected, the reduced thickness is equivalent to reducing the thickness of the carbon layer and the silver layer on the other side of the monolithic core 2.

[0045] Moreover, assuming that the external design is one that contains both an impregnated, coated or printed carbon layer and an impregnated, coated or printed silver layer, there may be a gap between the carbon layer and the silver layer, which may lead to a problem of excessive resistance, and a large amount of insulating material is provided in the carbon layer and the silver layer material, which also increases the resistance; the conductive foil 1 with a pre-coated carbon layer in the embodiment of the present invention can also improve the conductive performance of the capacitor 100, such as the conductivity is reduced from 7.68×10^-3 to 4.87×10^-5Ω·cm (see patent CN110444316A) to 2.8×10^-6Ω·cm, achieving a significant improvement in conductive performance; this improvement effectively reduces the equivalent series resistance of the product and improves the overall electrical performance. Moreover, the thickness of the carbon layer and the silver layer in the prior art is difficult to maintain a uniform coating, which may cause uneven distribution of current and heat in the capacitor 100. The conductive foil 1 with a pre-coated carbon layer in the embodiment of the present invention can make the current and heat distribution more uniform.

[0046] Moreover, the positive electrode plate 21 of the single-piece core 2 of the embodiment of the present invention is directly distributed along the first direction with the negative electrode area 23 of the single-piece core 2. Similarly, after the conductive foil 1 is connected to the negative electrode area 23 of the single-piece core 2, the conductive foil 1 is equivalent to the negative electrode, and the negative electrode plate 12 of the conductive foil 1 is also distributed along the first direction with the foil body 11. That is, the positive electrode plate 21 and the negative electrode plate 12 will not occupy the space between the single-piece core 2 and the inside of the conductive foil 1, and there is no separate metal lead, which is equivalent to reducing the thickness of the entire capacitor 100 without affecting the effective capacity of the capacitor 100. Compared with the prior art in which the positive electrode plate 21 and the negative electrode plate 12 mostly use metal leads located on both sides of the thickness direction of the single-piece core 2, the effective space is increased.

[0047] Moreover, the embodiment of the present invention also abandons the beveled edges and frame-type metal leads in the traditional design, and adopts a beveled edge and frameless design, which directly improves the space utilization by 10%. This design innovation not only simplifies the manufacturing process, but also makes the deployment of the capacitor 100 in a limited space more flexible and efficient.

[0048] Therefore, the embodiment of the present invention can reduce the thickness of the chip-type laminated solid aluminum electrolytic capacitor 100 by connecting the conductive foil 1 with the single-chip core 2, reduce the equivalent series resistance of the chip-type laminated solid aluminum electrolytic capacitor, and solve the problem of uneven distribution of current and heat inside the capacitor 100, while improving the conductive performance of the capacitor 100.

[0049] In some embodiments, there are multiple conductive structures, and when the multiple conductive structures are stacked and connected, each conductive foil 1 is located between two adjacent single-piece cores 2 .

[0050] That is to say, combined Figure 6 and Figure 7As shown, two adjacent monolithic cores 2 can share a conductive foil 1, while in the prior art, both sides of the monolithic core 2 are provided with a carbon layer and a silver layer. If one side has a carbon layer and a silver layer, when the adjacent monolithic cores 2 are stacked, there are two carbon layers and two silver layers between the adjacent monolithic cores 2. The conductive foil 1 between the two monolithic cores 2 of the embodiment of the present invention can be shared, thereby reducing the thickness of the multi-layer monolithic cores 2 when connected.

[0051] For example, in a capacitor 100 product with a specification thickness of 1.9 mm, when the thickness of a single monolithic core 2 in the prior art is 0.2 mm, the total irrelevant thickness is 0.9 mm, that is, a monolithic core 2 can be made into 5 layers, and after adaptively sacrificing the shell thickness, it can even be stacked into about 6 layers; when the embodiment of the present invention needs to make a capacitor 100 product with a specification thickness of 1.9 mm, no metal lead and lead bracket are set, and the total irrelevant thickness is about 0.4 mm, and the thickness of each conductive structure is 0.17 mm, that is, the thickness of a monolithic core 2 and a conductive foil 1 is 0.17 mm. Then, according to calculation, the monolithic core 2 of the embodiment of the present invention can be 7.6 layers. The embodiment of the present invention can also set the substrate 3 to 0.1 mm, and the thickness of the monolithic core 2 can be about 8 layers. That is, for the capacitor 100 product with the same thickness, the monolithic core 2 of the embodiment of the present invention has more layers, thereby making the capacity larger.

[0052] In some embodiments, the negative electrode region 23 of the single-piece core 2 and the substrate 3, as well as the foil body 11 and the negative electrode region 23 of the single-piece core 2 are bonded using a polymer dispersion, and the positive electrode sheet 21 and the substrate 3, as well as adjacent positive electrode sheets 21 are bonded using welding.

[0053] First, the negative electrode area 23 of the single-chip core 2 and the substrate 3 are bonded with a polymer dispersion, and the positive electrode plate 21 and the substrate 3 are welded to ensure the correct polarity. The positive and negative electrodes of the capacitor 100 have clear polarity requirements, which can ensure that the polarity of the capacitor is correctly connected to avoid problems such as circuit damage or capacitor explosion caused by reverse connection.

[0054] In addition, by bonding the negative electrode region 23 to the substrate 3, the capacitor can be better fixed to prevent it from falling off due to vibration or other factors during operation, thereby improving the stability of the circuit. The correct connection method can avoid safety problems caused by incorrect connection methods, such as short circuits or damage to the capacitor 100, thereby protecting the circuit board and other electronic components.

[0055] Furthermore, the polymer dispersion may adopt a water-soluble mixture of polythiophene, which not only has excellent photoelectric properties, but also can significantly improve its solubility in water by introducing water-soluble groups, such as sulfonic acid groups, thereby facilitating processing and application; in addition, polythiophene also has good conductivity, so that multiple monolithic cores 2 can be electrically connected.

[0056] In some embodiments, a positive electrode pad 33, a negative electrode pad 39 and a negative electrode bonding area 37 are provided on the substrate 3; the positive electrode pad 33 and the negative electrode pad 39 are spaced apart and distributed on the substrate 3 along the second direction, the negative electrode bonding area 37 and the negative electrode pad 39 are distributed on the substrate 3 along the first direction, and the negative electrode bonding area 37 and the negative electrode pad 39 are electrically connected through a transition area 38, the positive electrode sheet 21 is electrically connected to the positive electrode pad 33, and the negative electrode sheet 12 is at least partially electrically connected to the negative electrode pad 39, the middle area 22 of the single-piece core 2 is provided in the transition area 38, and the negative electrode area 23 of the single-piece core 2 is connected to the negative electrode bonding area 37 of the substrate 3.

[0057] Reference Figure 4 As shown, Figure 4 It is the front side of the substrate 3. First, the first direction is the length direction of the substrate 3, that is, Figure 4 The left and right directions of Figure 4 In the width direction, the positive electrode pad 33 and the negative electrode pad 39 on the substrate 3 are distributed along the width direction, so that after the conductive foil 1 and the single-piece core 2 are connected, the positive electrode sheet 21 of the single-piece core 2 is welded to the positive electrode pad 33 by laser welding, resistance welding or laser welding and resistance welding together, and the negative electrode sheet 12 of the conductive foil 1 is at least partially bonded to the negative electrode pad 39 with a water-soluble mixture of polythiophene, so that the positive electrode sheet 21 and the negative electrode sheet 12 are separated; and the negative electrode region 23 of the single-piece core 2 is bonded to the negative electrode bonding region 37 of the substrate 3. In addition, the middle region 22 of the single-piece core 2 is arranged in the transition region 38, and the transition region 38 is a transition copper cladding layer, which forms a conductive connection between the negative electrode bonding region 37 of the substrate 3 and the negative electrode pad 39, and cooperates with the middle region 22 of the single-piece core 2.

[0058] In some embodiments, a positive electrode pin 31 and a negative electrode pin 36 are provided on the back side of the substrate 3, and the positive electrode pin 31 and the negative electrode pin 36 are spaced apart along a first direction; the positive electrode pin 31 is electrically connected to a current limiting conductive plate 32, and the current limiting conductive plate 32 is provided with a first via hole 30, and the current limiting conductive plate 32 is electrically connected to a positive electrode pad 33 by passing a wire through the first via hole 30, and the negative electrode pin 36 is provided with a second via hole 35, and the negative electrode pin 36 is electrically connected to a negative electrode bonding area 37 by passing a wire through the second via hole 35, the positive electrode pin 31 is used to connect one end of an external circuit, and the negative electrode pin 36 is connected to the other end of the external circuit, and the current limiting conductive plate 32 is suitable for disconnecting the capacitor 100 from the external circuit when a fuse is blown between the first via hole 30 and the positive electrode pad 33.

[0059] In practice, refer to Figure 5 As shown, Figure 5 It is the back side of the substrate 3, the positive pin 31 on the back side of the substrate 3 is connected to the positive electrode of the external circuit, and the negative pin 36 is connected to the negative electrode of the external circuit, so that the capacitor 100 is connected to the external circuit, the positive pin 31 is generally a positive copper-clad pin, the negative pin 36 is generally a negative copper-clad pin, and the positive copper-clad pin is also connected to a current-limiting conductive plate 32, and a first via 30 is provided at one end of the current-limiting conductive plate 32. By passing a wire through the first via 30, the wire electrically connects the current-limiting conductive plate 32 with the positive pad 33.

[0060] That is, at this time, the current limiting conductive plate 32 is connected to the positive electrode pad 33, which is equivalent to the positive electrode pin 31 being connected to the positive electrode pad 33. Similarly, the second via 35 at the negative electrode pad 39 is connected to the negative electrode bonding area 37 located on the front side of the substrate 3 through a wire, so that the negative electrode pin 36 is electrically connected to the negative electrode bonding area 37, the positive electrode of the external circuit is connected to the positive electrode pin 31, and the negative electrode of the external circuit is connected to the negative electrode pin 36, so that the external circuit is connected between the positive electrode pin 31 and the negative electrode pin 36, which is equivalent to the state where the external circuit and the capacitor 100 are turned on at this time.

[0061] At this time, the current-limiting conductive plate 32 is a copper-clad circuit. When the capacitor 100 encounters an abnormally large voltage or large current impact and there is a risk of short circuit, the copper-clad circuit in this area will quickly melt, that is, the current-limiting conductive plate 32 will melt, thereby disconnecting the positive pin 31 from the positive pad 33 inside the capacitor 100, that is, isolating the capacitor 100 from the external circuit and turning it into an open circuit state, thereby avoiding fire caused by short circuit or damage to other electronic components. Among them, the board body 34 and the current-limiting conductive plate 32, positive pin 31, negative pin 36, positive pad 33 and negative pad 39 on the board body 34 form the entire substrate 3, which is also the circuit board.

[0062] Through the current limiting design, the capacitor 100 can automatically switch to the open circuit failure mode under extreme conditions, greatly reducing the degree of danger and protecting the safety of the circuit board and other electronic equipment. That is, the current limiting circuit is integrated on the substrate 3, and the safe and stable operation of the capacitor 100 can be ensured without the need for an external additional protection solution. This built-in safety measure not only simplifies the system design, but also greatly improves the reliability of the product and the convenience of user use.

[0063] In some embodiments, the current limiting conductive plate 32 includes a first section 321, a second section 322 and a third section 323 that are bent and connected. One end of the first section 321 is connected to the positive pin 31 and the other end extends in a direction away from the positive pin 31 to connect to the second section 322. The second section 322 is located on one side of the positive pin 31 in the first direction. The third section 323 is connected to the second section 322 and extends in a direction close to the positive pin 31 and is staggered with the positive pin 31. The first via 30 is located at one end of the third section 323 away from the second section 322.

[0064] In practice, by setting the current limiting conductive plate 32 as a first section 321, a second section 322 and a third section 323 that are bent and connected, it is convenient to connect the current limiting conductive plate 32 to the positive pin 31, and the other end of the current limiting conductive plate 32 can be connected to the positive electrode pad 33 at a closer distance through a wire passing through the first via 30; at the same time, the positive pin 31 is located at one end of the current limiting conductive plate 32, and the first via 30 is located at the other end of the current limiting conductive plate 32, so that the current limiting conductive plate 32 has a certain distance to be melted under the action of large current and high voltage.

[0065] Furthermore, the width of the second section 322 can be set to be smaller than the widths of the first section 321 and the third section 323, so that the second section 322 can be melted by large current and voltage. Since the second section 322 is the middle section connecting the positive pin 31 and the positive pad 33 connected by the wire through the first via 30, melting the second section 322 can not only achieve the rapid disconnection of the capacitor 100 from the external circuit, but also does not affect the structural setting at the positive pin 31 or the first via 30, and can achieve a faster disconnection of the capacitor 100 from the external circuit to protect the circuit.

[0066] The embodiment of the present invention further discloses a method for preparing the capacitor 100, which is used to prepare the above capacitor 100, comprising the following steps:

[0067] S1; prepare a single-piece core 2, and divide the single-piece core 2 into a negative electrode region 23, a middle region 22 and a positive electrode sheet 21.

[0068] In practice, before manufacturing the capacitor 100, the size of the single-piece core 2, the positive electrode plate 21 and the negative electrode area 23 are prepared, and the size of the negative electrode area 23, the middle area 22 and the positive electrode plate 21 of the single-piece core 2 are prepared according to the size of the negative electrode bonding area 37, the positive electrode pad 33 and other sizes of the substrate 3 to form a reasonable size match.

[0069] S2: preparing a conductive foil 1, and pre-plating a carbon layer on the outer surface of a conductive metal body to form a conductive foil 1.

[0070] For example, aluminum foil can be plated with carbon, or aluminum foil can be plated with titanium and carbon. For example, the conductive foil 1 can be made of aluminum foil, which has a rough upper surface and lower surface. Carbon is sputtered on the upper and lower surfaces of the corroded aluminum foil by magnetron sputtering under vacuum conditions. Figure 1 The conductive foil 1 is pre-coated with a carbon layer.

[0071] S3 ; installing the conductive structure, installing the single-piece core 2 on the substrate 3 , and superimposing the conductive foil 1 on the single-piece core 2 , and connecting the negative electrode plate 12 of the conductive foil 1 to the substrate 3 .

[0072] Specifically, the single-piece core 2 is installed on the substrate 3, and the positive electrode plate 21 is also installed on the substrate 3, and then the foil body 11 of the conductive foil 1 is connected to the negative electrode area 23 of the single-piece core 2, and the negative electrode plate 12 of the conductive foil 1 is connected to the substrate 3; of course, if there are multiple single-piece cores 2, the negative electrode area 23 of another single-piece core 2 is continued to be connected to the foil body 11 of the conductive foil 1, and the positive electrode plate 21 of the single-piece core 2 is stacked and connected above the positive electrode plate 21 of the bottom single-piece core 2, thereby forming a parallel connection of multiple positive electrode plates 21.

[0073] Therefore, the conductive foil 1 of the embodiment of the present invention is connected to the monolithic core 2, and there is no need to apply another coating on the monolithic core 2, thereby reducing the thickness of each monolithic core 2. In particular, when there are multiple monolithic cores 2, two adjacent monolithic cores 2 share a conductive foil 1, and there is no need to apply a conductive layer on both sides of each monolithic core 2, thereby reducing the thickness of the entire capacitor 100; when there are multiple monolithic cores 2, the number of layers of the monolithic core 2 in the capacitor 100 of the same thickness can be achieved, thereby increasing the effect of increasing the capacitance. Similarly, when there is only one layer of the monolithic core 2 and the conductive foil 1, the thickness of the monolithic core 2 can also be made thinner, and no coating is provided on both sides of the monolithic core 2 in the thickness direction. The conductive foil 1 can be connected to one side of the monolithic core 2, and the other side does not need to be coated to reduce the thickness. In addition, the positive electrode sheet 21 is located on one side of the length direction of the negative electrode region 23, not on one side in the thickness direction, which can also reduce the overall thickness of the capacitor 100.

[0074] In some embodiments, preparing the monolithic core 2 includes:

[0075] S11: Cutting: selecting the anode foil and cutting the anode foil into a plurality of monomers of required sizes.

[0076] The anode foil can be made of aluminum to save costs. The anode foil is cut into the required width of 1.2-20 mm, preferably 3.0-4.0 mm, preferably 3.5 mm-3.8 mm. Figure 2 The width of the rectangular cross section is cut into multiple monomers of required sizes, and the length can be determined according to the required size of the actual capacitor 100. Multiple single-piece cores 2 can be processed simultaneously, thereby facilitating the preparation of capacitors 100 with multiple capacities.

[0077] S12: arranging the plurality of monomers on the process iron bar.

[0078] Arranging multiple monomers makes it easier to select the monomers and to perform subsequent one-time processing, thereby improving processing efficiency.

[0079] S13: Glue coating: coating the arranged multiple monomers with insulating glue lines to isolate the negative electrode area 23 and the positive electrode plate 21.

[0080] When multiple monomers are arranged on the process iron bar along the length direction of the process iron bar, when applying glue, multiple monomers can be coated with insulating glue lines at the same position along the first direction at the same time, so that the insulating glue lines form an insulating layer in the middle area 22 of the above-mentioned single-piece core 2, thereby improving the glue application efficiency.

[0081] S14: chemical formation, repairing the oxide layer 232 of the plurality of monomers.

[0082] Specifically, the negative electrode regions 23 of multiple monomers arranged on the process iron bar are placed in an oxalic acid solution or a solution such as ammonium adipate, and electricity is applied to form aluminum oxide. The aluminum oxide is the oxide layer 232 of the negative electrode region 23 of the single-piece core 2. The purpose of the formation is to repair the oxide layer 232 of the negative electrode region 23. The formation process is mainly used to ensure the integrity of the oxide layer 232 on the surface of the metal core 231, thereby ensuring the integrity of the dielectric of the capacitor 100, so as to isolate the charge and enhance the charge storage capacity.

[0083] S15; coating to form a conductive polymer layer 233 on the surface of the negative electrode region 23 to form a single-piece core 2.

[0084] That is, a conductive polymer layer 233 is formed on the outer surface of the oxide layer 232 of the negative electrode region 23, and its main function is to form a cathode layer. This cathode layer has high conductivity and can significantly reduce the equivalent series resistance (ESR) of the capacitor, thereby improving the performance of the capacitor in high-frequency circuits, more effectively filtering out ripple current and noise, and providing a stable capacitance value, so that the capacitor maintains stable performance over a wide temperature range; in addition, the conductive polymer layer 233 can also protect the single-chip core 2 to increase the stability of the performance of the single-chip core 2, and improve the moisture-proof, waterproof, anti-fouling, wear-resistant and chemical corrosion-resistant properties of the single-chip core 2.

[0085] Moreover, the metal core 231 in the middle of the negative electrode region 23 serves as one electrode plate of the capacitor 100, the conductive polymer layer 233 forms another electrode plate of the capacitor 100, and the oxide layer 232 is a dielectric layer between the two electrodes of the capacitor 100. That is, through the above process, a single-piece core 2 of a required size can be prepared, and the negative electrode region 23 and the positive electrode plate 21 of the single-piece core 2 can be formed, so that the capacitor 100 has the ability to store charge.

[0086] In some embodiments, installing the conductive structure includes: S31 ; dividing the main substrate 3 into a plurality of mounting areas 301 , wherein the plurality of mounting areas 301 are arranged in a plurality of rows horizontally and in a plurality of columns vertically, and each mounting area 301 is installed with a conductive structure.

[0087] Reference Fig.13 As shown, the main substrate 3 is divided into multiple installation areas 301, which can facilitate and efficiently set up multiple capacitors 100 to form a process-based operation; for example, each installation area 301 is first provided with a corresponding positive electrode pad 33, a negative electrode pad 39, a negative electrode bonding area 37, etc., and a single-chip core 2 is installed in each installation area 301, and then a conductive foil 1 is bonded on the top of each single-chip core 2 by a polymerizing liquid, the thickness of the polymerizing liquid can be ignored, and a single-chip core 2 is connected to each conductive foil 1, and so on, a plurality of multi-capacity capacitors 100 can be formed; thus, the main substrate 3 is divided into multiple installation areas 301, and the production efficiency of the capacitor 100 is improved.

[0088] S32: Plastic-encapsulate the conductive structure of each mounting area 301.

[0089] The thickness of the substrate 3 is 0.1mm to 0.5mm. After the single-chip core 2 and the conductive foil 1 are installed in each installation area 301 of the substrate 3, a layer of epoxy resin is molded and covered as a whole. The thickness of the epoxy resin can be adjusted according to the actual situation, and the thinnest can be 0.3mm. For example, for a 1.9mm thick product, if only 2 layers are stacked, assuming that the thickness of the substrate 3 is 0.4mm, then the thickness of the resin is 1.9-0.4-2*0.17=1.16mm (the thickness of the conductive structure is 0.17mm). If 8 layers are stacked, assuming that the thickness of the substrate 3 is 0.1mm, the thickness calculation formula of the resin part is 1.9-0.1-8*0.17=0.44mm. For another example, for a 0.6mm thick capacitor 100, when a layer of conductive structure is set, the thickness of the epoxy resin can be 0.6-0.1-0.17=0.33mm, that is, the thickness of the epoxy resin is the thinnest 0.3mm. After each mounting area 301 is mounted with a single-chip core 2 and a conductive foil 1 and then plastic-sealed, the protection of the internal single-chip core 2 can be improved, and the inside of the capacitor 100 can be isolated from the outside. In addition, the integrity of the capacitor 100 can be improved.

[0090] S33 ; the positive electrode sheets 21 and the negative electrode sheets 12 of the plurality of capacitors 100 are located on the same side of the first direction of the overall substrate 3 .

[0091] Continue to refer to Fig.13 As shown, the positive electrode sheet 21 of the single-piece core 2 and the negative electrode sheet 12 of the conductive foil 1 of each capacitor 100 are both located on the left side of each mounting area 301, that is, when the total substrate 3 is a rectangle, the first direction at this time is Fig.13 On one side in the length direction, that is, all capacitors 100 are arranged in the same manner, which can facilitate subsequent segmentation and orderly operation.

[0092] S34 ; dividing the main substrate 3 into a plurality of sub-substrates 3 and a corresponding plurality of capacitors 100 along the second direction.

[0093] For the rectangular main substrate 3, the second direction is the width direction of the main substrate 3. At this time, the main substrate 3 is divided into a plurality of sub-substrates 3 along the second direction, that is, the main substrate 3 is first divided into a plurality of columns, and each column of the sub-substrates 3 corresponds to a plurality of mounting areas 301 and a plurality of capacitors 100. The structure after division is as follows: Fig.14 As shown, the structure of each secondary substrate 3 is the same, which provides convenience for subsequent operations.

[0094] S35: electroplating the two end surfaces of the corresponding capacitors 100 on each sub-substrate 3 along the first direction.

[0095] That is, each secondary substrate 3 has both sides along the length direction plated with a conductive layer, that is, when the final product of the capacitor 100 is put into use, it can be welded with other circuit boards, and the end face along the length direction is also provided with a plated layer, which can be soldered to other circuit boards to increase the welding strength, that is, the plated conductive layer can achieve the welding strength when the final capacitor 100 is used. For example, the left side of the secondary substrate 3 along the first direction can be called the positive electrode plated end face 41, and the right side can be called the negative electrode plated end face 42, which can be referred to Figure 5 As shown, the positive electrode electroplating end face 41 is close to the positive electrode pin 31, and the negative electrode electroplating end face 42 is close to the negative electrode pin 36. The positive electrode pin 31 and the negative electrode pin 36 are both connected to the external circuit, that is, when the actual capacitor 100 is put into use, the positive electrode pin 31 and the negative electrode pin 36 are connected through the external circuit. At the same time, the electroplated conductive layer can increase the welding effect of the capacitor 100 with other structures such as circuit boards.

[0096] That is, the positive pole pieces 21 of the plurality of single-piece cores 2 and the negative pole pieces 12 of the conductive foil 1 are located on the same side of the main substrate 3, and the main substrate 3 is divided into a plurality of sub-substrates 3 along the second direction, so that the conductive layer can be conveniently plated on both sides of each capacitor 100 along the length direction, that is, along the Fig.14 The left and right sides of the coating can improve the coating efficiency.

[0097] S36 ; cutting the plurality of capacitors 100 corresponding to each sub-substrate 3 into individual capacitors 100 along the first direction.

[0098] Reference Fig.14 As shown, at this time, the plurality of capacitors 100 are divided along the first direction, and the division is repeated multiple times, so that the plurality of capacitors 100 corresponding to each secondary substrate 3 can form independent capacitors 100 .

[0099] S37: Check the quality of the products and exclude unqualified products. The manufactured capacitors 100 are tested to improve the qualified rate of the capacitors 100 and make the products put into use as qualified as possible.

[0100] In some embodiments, testing the eligibility of a product includes:

[0101] S371; Perform aging treatment on the single capacitor 100; The aging treatment of the capacitor 100 refers to long-term operation and load testing of the single-chip core 2 under certain environmental temperature and electrical stress conditions to simulate the aging of the single-chip core 2 in actual use; The purpose of this treatment method is to evaluate the reliability and performance stability of the single-chip core 2 under long-term use and load conditions, so as to determine its life and reliability indicators; that is, to prompt the potential defects hidden inside the single-chip core 2 to be exposed as early as possible, so as to achieve the purpose of eliminating early failed products.

[0102] S372; reflow soldering test, applying reflow soldering high temperature to the capacitor 100; reflow soldering test refers to a series of tests performed on the capacitor 100 after reflow soldering, mainly involving the quality, reliability, stability and other aspects of the capacitor 100.

[0103] Reflow testing usually includes solder joint quality testing, dimension testing and electrical performance testing.

[0104] 1. Detect the quality of all solder joints on the substrate 3. Through the solder joint quality test, the quality, strength, reliability and other indicators of the solder joints can be evaluated, and necessary adjustments can be made to the solder joint quality to ensure the stability and reliability of the solder joints and avoid problems such as loose solder joints and falling off. 2. Another purpose of the reflow test is to detect whether the bonding between the substrate 3 and the epoxy resin is cracked. 3. Another important purpose of the reflow test is to test the electrical properties of the capacitor 100. The electrical performance test mainly includes tests on capacitance, loss tangent, leakage current, equivalent series resistance, etc. Through the electrical performance test, the stability and reliability of the capacitor 100 can be evaluated, and necessary adjustments can be made to the electrical performance of the capacitor 100 to ensure that the capacitor 100 can work normally, while avoiding problems such as failure of the capacitor 100 due to electrical performance problems of the capacitor 100.

[0105] S373: Testing and sorting, testing the capacitors 100 for parameters, and eliminating the capacitors 100 with unqualified parameters. Through the above-mentioned tests and sorting, some unqualified products are eliminated, and then testing is performed again to further improve the qualified rate of the products.

[0106] The embodiment of the present invention also selected three groups of comparative examples, and compared the three groups of comparative examples with the solutions of the embodiment of the present invention to draw conclusions.

[0107] Embodiment 1 of the present invention: After preparing a single core 2 and a pre-carbon-coated conductive foil 1 by the above-mentioned preparation method of the capacitor 100, a combination of a pre-carbon-coated conductive foil 1 and a single core 2 is selected, and then stacked on a substrate 3, so that the sum of the thickness of each conductive foil 1 and each single core 2 is 0.17 mm.

[0108] Example 2: After preparing a monolithic core 2 and a pre-carbon-coated conductive foil 1 using the above-mentioned method for preparing the capacitor 100, select a combination of 5 pre-carbon-coated conductive foils 1 and 5 monolithic cores 2, and set conductive foils 1 between adjacent monolithic cores 2, connect the bottom monolithic core 2 to the substrate 3, and the remaining steps are the same.

[0109] Example 3: After preparing the monolithic core 2 and the pre-carbon-coated conductive foil 1 by the above-mentioned preparation method of the capacitor 100, select a combination of 8 pre-carbon-coated conductive foils 1 and 8 monolithic cores 2, and set the conductive foil 1 between adjacent monolithic cores 2, connect the bottom monolithic core 2 to the substrate 3, and the remaining steps are the same.

[0110] Comparative Example 1: When preparing a monolithic core 2, a carbon layer and a silver layer are coated on the outside of the conductive polymer layer 233 of the monolithic core 2. The thickness of each monolithic core 2 after coating with the carbon layer and the silver layer is 0.2 mm. One monolithic core 2 is overlapped on the surface of a lead bracket, and the lead bracket with the monolithic core 2 is wrapped and packaged with an insulating resin. The lead bracket is bent and fitted to the end and the bottom to form a lead terminal.

[0111] Comparative Example 2: When preparing the monolithic core 2, a carbon layer and a silver layer are further coated on the outside of the conductive polymer layer 233 of the monolithic core 2, three monolithic cores 2 are overlapped on one surface of the lead bracket, and two monolithic cores 2 are overlapped on the other surface of the lead bracket, that is, a combination of five monolithic cores 2, and the remaining steps are the same as those in Comparative Example 1.

[0112] Comparative Example 3: When preparing the monolithic core 2, a carbon layer and a silver layer are further coated on the outside of the conductive polymer layer 233 of the monolithic core 2, and four monolithic cores 2 are overlapped on one surface of the lead bracket, and four monolithic cores 2 are overlapped on the other surface of the lead bracket, that is, a combination of eight monolithic cores 2, and the remaining steps are the same as those in Comparative Example 1.

[0113] The basic performance results of the products obtained in the three embodiments and the products of the same specifications prepared by the traditional manufacturing process, i.e., coating the carbon layer and the silver layer, are shown in Table 1.

[0114] Table 1

[0115]

[0116] As can be seen from Table 1, the embodiment of the present invention can optimize the thickness of the single-chip core 2 to increase the available space of the product, thereby optimizing the thickness of the product. Compared with the product obtained by the traditional preparation process with the same specifications, the packaging thickness is smaller and the equivalent series resistance is also smaller.

[0117] In addition, the overall process of the method for preparing a capacitor according to an embodiment of the present invention is as follows: Fig.12 As shown, after the plastic encapsulation, that is, setting the resin layer for plastic encapsulation, the strip cutting includes cutting the main substrate 3 along the second direction as mentioned above to form a secondary substrate 3, and then dicing the multiple capacitors 100 corresponding to each secondary substrate 3 along the first direction, and then aging, reflow soldering detection, test sorting, product packaging, inspection and warehousing are carried out to prevent unqualified products from flowing to customers.

[0118] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0119] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A capacitor, characterized in that: include: substrate; At least one conductive structure, at least one conductive structure is stacked on the substrate along the thickness direction of the substrate, each conductive structure comprises a single core and a conductive foil, the single core comprises a negative electrode region, a middle region and a positive electrode sheet connected in sequence along a first direction, the middle region is coated with an insulating layer, and the conductive foil comprises a foil body and a negative electrode sheet connected along the first direction; Among them, the foil body is overlapped and adhered to the negative electrode area, a part of the negative electrode plate is overlapped and adhered to the insulating layer of the middle area and the other part is spaced apart and distributed along the second direction from the positive electrode plate, and the positive electrode plate and the negative electrode plate are electrically connected to the substrate respectively.

2. The capacitor according to claim 1, characterized in that There are a plurality of the conductive structures, and when the plurality of the conductive structures are stacked and connected, each of the conductive foils is located between two adjacent single-piece cores.

3. The capacitor according to claim 2, characterized in that The negative electrode region of the single-piece core and the substrate, as well as the foil body and the negative electrode region of the single-piece core are bonded by polymer dispersion, and the positive electrode sheet and the substrate, as well as adjacent positive electrode sheets, are welded.

4. The capacitor according to claim 1, characterized in that The substrate is provided with a positive electrode pad, a negative electrode pad and a negative electrode bonding area; The positive electrode pad and the negative electrode pad are distributed on the substrate at intervals along the second direction, the negative electrode bonding area and the negative electrode pad are distributed on the substrate along the first direction, and the negative electrode bonding area and the negative electrode pad are electrically connected through a transition area, the positive electrode sheet is electrically connected to the positive electrode pad, and the negative electrode sheet is at least partially electrically connected to the negative electrode pad, the middle area of ​​the single-piece core is arranged in the transition area, and the negative electrode area of ​​the single-piece core is connected to the negative electrode bonding area of ​​the substrate.

5. The capacitor according to claim 4, characterized in that A positive electrode pin and a negative electrode pin are provided on the back side of the substrate, and the positive electrode pin and the negative electrode pin are spaced apart and distributed along the first direction; The positive pin is electrically connected to a current limiting conductive plate, the current limiting conductive plate is provided with a first via hole, the current limiting conductive plate is electrically connected to the positive pad by passing a wire through the first via hole, the negative pin is provided with a second via hole, the negative pin is electrically connected to the negative bonding area by passing a wire through the second via hole, the positive pin is used to connect one end of an external circuit, the negative pin is connected to the other end of the external circuit, and the current limiting conductive plate is suitable for disconnecting the capacitor from the external circuit when the first via hole and the positive pad are melted.

6. The capacitor according to claim 5, characterized in that The current limiting conductive plate includes a first section, a second section and a third section that are bent and connected, one end of the first section is connected to the positive pin and the other end extends in a direction away from the positive pin to connect to the second section, the second section is located on one side of the positive pin in the first direction, the third section is connected to the second section and extends in a direction close to the positive pin and is staggered with the positive pin, and the first via is located at one end of the third section away from the second section.

7. A method for preparing a capacitor, used for preparing the capacitor according to any one of claims 1 to 6, characterized in that: The following steps are involved: Prepare the single-piece core, and divide the single-piece core into a negative electrode region, a middle region and a positive electrode sheet; The conductive foil is prepared by pre-plating a carbon layer on the outer surface of a conductive metal body to form the conductive foil; The conductive structure is installed, the single-piece core is installed on the substrate, and the conductive foil is stacked and connected to the single-piece core, and the negative electrode of the conductive foil is connected to the substrate.

8. The method for preparing a capacitor according to claim 7, characterized in that: The preparation of the monolithic core comprises: Cutting: selecting the anode foil and cutting the anode foil into a plurality of monomers of required sizes; Arranging, arranging a plurality of the monomers on a process iron bar; Gluing: coating the arranged plurality of monomers with insulating glue lines to isolate the negative electrode region and the positive electrode sheet; Chemically forming and repairing the oxide layers of the plurality of monomers; A conductive polymer layer is formed on the surface of the negative electrode region to form the monolithic core.

9. The method for preparing a capacitor according to claim 7, characterized in that: The installation conductive structure comprises: Dividing the main substrate into a plurality of mounting areas, the plurality of mounting areas are arranged in a plurality of rows horizontally and in a plurality of columns vertically, and each mounting area is provided with the conductive structure; Plastic-sealing the conductive structure of each mounting area; The positive electrode sheets and the negative electrode sheets of the plurality of capacitors are located on the same side of the first direction of the overall substrate; Dividing the main substrate into a plurality of sub-substrates and a corresponding plurality of the capacitors along the second direction; Electroplating the two end surfaces of the corresponding plurality of capacitors on each secondary substrate along the first direction; Cutting the plurality of capacitors corresponding to each of the sub-substrates into individual capacitors along the first direction; Test the eligibility of products and eliminate unqualified products.

10. The method for preparing a capacitor according to claim 9, characterized in that: The eligibility of the tested products includes: Performing an aging process on a single capacitor; Reflow soldering test, applying reflow soldering high temperature to the capacitor; Testing and sorting: performing parameter tests on the capacitors to exclude the capacitors with unqualified parameters.

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