CN112435853A

CN112435853A - Surface-packaged capacitor and manufacturing method thereof

Info

Publication number: CN112435853A
Application number: CN202011391423.2A
Authority: CN
Inventors: 宁连才; 黄建耀; 杨凯
Original assignee: State Run Factory 4326 of China Zhenhua Group Xinyun Electronic Comp and Dev Co Ltd
Current assignee: State Run Factory 4326 of China Zhenhua Group Xinyun Electronic Comp and Dev Co Ltd
Priority date: 2020-12-03
Filing date: 2020-12-03
Publication date: 2021-03-02

Abstract

The application provides a surface-mount capacitor and a method for manufacturing the same, the surface-mount capacitor includes: an anode element and a cathode element isolated from each other; an anode lead-out wire; the device comprises a substrate, a first substrate and a second substrate, wherein an anode connecting groove and a cathode connecting groove are formed in the substrate; electric conductors are arranged in the anode connecting groove and the cathode connecting groove; the anode bottom terminal is connected with a notch at one side of the anode connecting groove; one end of the conductor arranged in the anode connecting groove is connected with the anode leading-out wire, and the other end of the conductor arranged in the anode connecting groove is connected with the upper surface of the anode bottom surface terminal; the cathode bottom terminal is connected with a side notch of the cathode connecting groove; one end of the conductor arranged in the cathode connecting groove is connected with the cathode element, and the other end of the conductor arranged in the cathode connecting groove is connected with the upper surface of the cathode bottom surface terminal. Through the structure, the ESR value of the surface packaging capacitor is reduced, and the reliability of the surface packaging capacitor is improved.

Description

Surface-packaged capacitor and manufacturing method thereof

Technical Field

The application relates to the technical field of capacitors, in particular to a surface-packaged capacitor and a manufacturing method of the surface-packaged capacitor.

Background

In the prior surface-packaged capacitor, the terminal lead-out mainly depends on a cathode lead-out terminal and an anode lead-out terminal to lead the inside out to a bottom terminal. The mode has small connection area and single lead-out path, so that the surface packaging capacitor is unstable in connection and high in use risk, and the ESR (Equivalent Series Resistance) value of the surface packaging capacitor is large.

Disclosure of Invention

An object of the present invention is to provide a surface mount capacitor and a method for manufacturing the same, so as to solve the problem of unstable connection, high risk of use and large ESR of the surface mount capacitor.

The invention is realized by the following steps:

in a first aspect, an embodiment of the present application provides a surface-mount capacitor, including an anode element and a cathode element isolated from each other; an anode lead line connected to the anode element; the outer parts of the anode lead-out wire, the anode element and the cathode element are filled with packaging materials; the substrate is arranged at the bottoms of the anode element and the cathode element, and an anode connecting groove and a cathode connecting groove are formed in the substrate; electric conductors are arranged in the anode connecting groove and the cathode connecting groove; the anode bottom terminal is arranged at the bottom of the substrate and is connected with a side notch of the anode connecting groove; one end of the conductor arranged in the anode connecting groove is connected with the anode leading-out wire, and the other end of the conductor arranged in the anode connecting groove is connected with the upper surface of the anode bottom surface terminal; the cathode bottom terminal is arranged at the bottom of the substrate and is connected with a side notch of the cathode connecting groove; one end of the conductor arranged in the cathode connecting groove is connected with the cathode element, and the other end of the conductor arranged in the cathode connecting groove is connected with the upper surface of the cathode bottom surface terminal; an anode lead-out terminal connected to the anode lead-out wire and the anode bottom surface terminal; and a cathode lead terminal connected to the cathode element and the cathode bottom surface terminal.

In this application embodiment, through seting up anode connection groove and cathode connection groove on the base plate, make the anode element can switch on with positive pole bottom surface terminal through the electric conductor in the anode connection groove, the cathode element can switch on with negative pole bottom surface terminal through the electric conductor in the cathode connection groove, make to form two parallelly connected equivalent resistance of way between anode element and the positive pole bottom surface terminal, form two parallelly connected equivalent resistance of way between cathode element and the negative pole bottom surface terminal, and then reduced surface package capacitor's ESR value, surface package capacitor's reliability has been improved.

With reference to the technical solution provided by the first aspect, in some possible implementations, the anode lead-out wire is connected to the first surface of the anode element.

In the embodiment of the application, the anode lead-out wire is connected with the surface of the anode element, so that the anode lead-out wire does not occupy the effective volume of the anode element, thereby effectively improving the capacity ratio of the surface-mount capacitor and improving the utilization rate of the anode element.

With reference to the technical solution provided by the first aspect, in some possible implementations, the anode lead wire and the first surface of the anode element are formed by welding or sintering.

In the embodiment of the application, the anode lead wire and the surface of the anode element are connected in a welding or sintering mode, so that the stable connection between the anode lead wire and the anode element can be ensured, and the stability of the surface-packaged capacitor is further improved.

With reference to the technical solution provided by the first aspect, in some possible implementations, the anode lead-out wire is disposed below a center line of the first surface of the anode element.

In this application embodiment, through the central line below with the setting of anode outgoing line at the first surface of anode element for the anode outgoing line is more close to positive pole bottom surface terminal, through this mode, has reduced the preparation degree of difficulty of surface mount capacitor, has reduced the length of conducting path, and then has reduced surface mount capacitor's ESR value, has promoted surface mount capacitor's wholeness ability.

With reference to the technical solution provided by the first aspect, in some possible implementation manners, the anode lead-out wire is of a threaded structure.

In this application embodiment, the positive pole lead-out wire adopts screw thread structure for among the texture of packaging material can fill to screw thread structure's positive pole lead-out wire, increased the combination area between positive pole lead-out wire and the packaging material, and then strengthened the cohesion between positive pole lead-out wire and the packaging material, prevented the production in gap and outside moisture entering, improved the reliability of product.

With reference to the technical solution provided by the first aspect, in some possible implementation manners, the anode lead-out wire adopts a sawtooth structure.

In this application embodiment, the positive pole lead-out wire adopts the sawtooth structure for among the packaging material can fill the clearance to the positive pole lead-out wire of sawtooth structure, increased the combination area between positive pole lead-out wire and the packaging material, and then strengthened the cohesion between positive pole lead-out wire and the packaging material, prevented the production in gap and outside moisture entering, improved the reliability of product.

With reference to the technical solution provided by the first aspect, in some possible implementation manners, a diameter of a side of the anode lead-out wire close to the anode lead-out end is larger than a diameter of a side of the anode lead-out wire close to the anode element.

In this application embodiment, the diameter that the anode lead-out wire is close to anode lead-out end one side is greater than the diameter that is close to anode element one side on the anode lead-out wire, one, make the area that the end was drawn out to anode lead-out wire and anode great, improve the reliability that the two is connected, the ESR value of surface mount capacitor has been reduced, two, because anode lead-out wire both ends diameter is different, the bonding area between anode lead-out wire and the packaging material has also been increased, and then the cohesion between anode lead-out wire and the packaging material has been strengthened, the production and the outside moisture entering in gap have been prevented, the reliability of product is improved.

With reference to the technical solution provided by the first aspect, in some possible implementations, the cathode element is disposed on an outer layer of the anode element, a dielectric layer is disposed between the cathode element and the anode element, and the cathode element includes a cathode layer, a carbon layer, and a silver layer that are sequentially disposed; an insulator is arranged between the conductor in the anode connecting groove and the cathode element.

In the embodiment of the application, the insulator is arranged between the conductor and the cathode element in the anode connecting groove, so that short circuit between the conductor and the cathode element in the anode connecting groove can be effectively protected.

In combination with the technical solution provided by the first aspect, in some possible implementations, the cathode layer of the cathode element includes one or more of manganese dioxide, polypyrrole, polythiophene, polyaniline, and polyphenyl propylamine, and their respective derivatives.

In combination with the technical solution provided by the first aspect, in some possible implementation manners, the electrical conductor is a conductive silver paste.

With reference to the technical solution provided by the first aspect, in some possible implementation manners, the number of the anode connecting grooves formed in the substrate is at least two; the number of the cathode connecting grooves formed in the substrate is at least two.

In the embodiment of the application, the at least two anode connecting grooves are formed in the substrate, and the at least two cathode connecting grooves are formed in the substrate, so that the multipath parallel equivalent resistance is formed between the anode element and the anode bottom surface terminal, and the multipath parallel equivalent resistance is formed between the cathode element and the cathode bottom surface terminal, so that the ESR value of the surface-packaged capacitor is further reduced, and the reliability of the surface-packaged capacitor is improved.

With reference to the technical solution provided by the first aspect, in some possible implementation manners, an area of a sum of the anode connecting grooves and the cathode connecting grooves is 10% to 80% of an area of a sum of the anode bottom surface terminal and the cathode bottom surface terminal.

In the embodiment of the application, the added area of the anode connecting groove and the cathode connecting groove is 10-80% of the added area of the anode bottom surface terminal and the cathode bottom surface terminal, and the reliability of the surface-packaged capacitor is ensured through reasonable arrangement.

With reference to the technical solution provided by the first aspect, in some possible implementation manners, the anode connecting groove is formed in one side of the substrate close to the anode leading-out end, and one side of the anode connecting groove close to the anode leading-out end is opened, so that the anode leading-out end is connected with the conductor in the anode connecting groove; the cathode connecting groove is formed in one side, close to the cathode leading-out end, of the substrate, and is opened in one side, close to the cathode leading-out end, of the cathode connecting groove, so that the cathode leading-out end is connected with the conductor in the cathode connecting groove.

In the embodiment of the application, the anode connecting groove is arranged at one side of the substrate close to the anode leading-out end, and one side of the anode connecting groove close to the anode leading-out end is opened; the cathode connecting groove is arranged on one side, close to the cathode leading-out end, of the substrate, and the cathode connecting groove is opened on one side, close to the cathode leading-out end, of the substrate.

With reference to the technical solution provided by the first aspect, in some possible implementations, the notch on the other side of the anode connecting groove extends to be connected with the anode outgoing line; the other side notch of the cathode connecting groove extends to be connected with the cathode element.

In this application embodiment, the opposite side notch of anode connection groove directly extends to and is connected with the anode lead-out wire, and the opposite side notch of cathode connection groove extends to and is connected with the cathode element, through this mode, has guaranteed that the electric conductor in the anode connection groove can effectual intercommunication anode lead-out wire and positive pole bottom surface terminal, is difficult for producing the deformation, has also guaranteed that the electric conductor in the cathode connection groove can effectual intercommunication cathode element and negative pole bottom surface terminal, is difficult for producing the deformation.

With reference to the technical solution provided by the first aspect, in some possible implementations, the anode element is a tantalum block; the cathode element is arranged on the outer layer of the tantalum block, a dielectric layer is arranged between the cathode element and the tantalum block, and the cathode element comprises a cathode layer, a carbon layer and a silver layer which are sequentially arranged.

With reference to the technical solution provided by the first aspect, in some possible implementations, the anode element is an aluminum block; the cathode element is arranged on the outer layer of the aluminum block, a dielectric layer is arranged between the cathode element and the aluminum block, and the cathode element comprises a cathode layer, a carbon layer and a silver layer which are sequentially arranged.

In a second aspect, an embodiment of the present application provides a method for manufacturing a surface mount capacitor, where the method includes: providing a substrate; forming an anode connecting groove and a cathode connecting groove on the substrate through laser engraving; filling an electric conductor into the anode connecting groove and the cathode connecting groove; bonding the prepared anode block on the substrate, so that the electric conductor in the anode connecting groove is connected with the anode lead-out wire and the anode bottom surface terminal, and the electric conductor in the cathode connecting groove is connected with the cathode element and the cathode bottom surface terminal; and carrying out packaging test on the anode block.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a surface mount capacitor in the prior art.

Fig. 2 is a schematic structural diagram of a first surface mount capacitor according to an embodiment of the present disclosure.

Fig. 3 is a schematic structural diagram of a second surface mount capacitor according to an embodiment of the present disclosure.

Fig. 4 is a schematic structural diagram of a third surface mount capacitor provided in the embodiment of the present application.

Fig. 5 is a schematic structural diagram of a fourth surface mount capacitor provided in the embodiment of the present application.

Fig. 6 is a schematic structural diagram of a fifth surface mount capacitor according to an embodiment of the present disclosure.

Fig. 7 is a schematic structural diagram of a sixth surface mount capacitor according to an embodiment of the present disclosure.

Fig. 8 is a schematic diagram of connection between an anode lead wire and an anode element according to an embodiment of the present disclosure.

Fig. 9 is a schematic structural diagram of a first anode lead-out wire according to an embodiment of the present disclosure.

Fig. 10 is a schematic structural diagram of a second anode lead-out wire according to an embodiment of the present application.

Fig. 11 is a schematic structural diagram of a third anode lead-out wire provided in an embodiment of the present application.

Fig. 12 is a schematic structural diagram of a fourth anode lead-out wire according to an embodiment of the present application.

Fig. 13 is a circuit diagram for supplying power to an FPGA CPU according to an embodiment of the present disclosure.

Fig. 14 is a flowchart illustrating a method for manufacturing a surface mount capacitor according to an embodiment of the present disclosure.

Fig. 15 is a flowchart illustrating a process of manufacturing a surface mount capacitor according to an embodiment of the present disclosure.

Icon: 100-surface package capacitor; 1-an anode element; 2-a cathode element; 20-a dielectric layer; 21-a cathode layer; a 22-carbon layer; 23-a silver layer; 24-cathode silver paste; 3-anode leading-out end; 4-cathode leading-out terminal; 5-anode lead-out wire; 6-anode bottom terminal; 7-cathode bottom terminal; 8-a substrate; 9-packaging material; 10-anode connecting groove; 11-cathode connecting grooves; 12-insulator.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

In the prior surface-packaged capacitor, the terminal lead-out mainly depends on a cathode lead-out terminal and an anode lead-out terminal to lead the inside out to a bottom terminal. As shown in fig. 1, the prior art discloses a surface-mount capacitor, which is composed of an anode block, cathode silver paste, an anode terminal, a cathode terminal, an anode connecting wire, an anode bottom terminal, a cathode bottom terminal, and a substrate. The surface-packaged capacitor leads the anode out to the anode bottom terminal through the anode connecting wire and the anode leading-out end; the cathode is led out to the cathode bottom surface terminal through the cathode lead-out terminal. As can be seen from the figure, the connection area of the surface-mount capacitor is small, so that the surface-mount capacitor is unstable in connection and high in use risk, and the ESR value of the surface-mount capacitor is large.

In view of the above problems, the present inventors have studied and researched to provide the following embodiments to solve the above problems.

Referring to fig. 2, an embodiment of the present invention provides a surface mount capacitor 100, including: anode element 1, cathode element 2 (cathode element 2 is arranged on the outer layer of anode element 1), anode lead-out terminal 3, cathode lead-out terminal 4, anode lead-out terminal 5, anode bottom terminal 6, cathode bottom terminal 7 and substrate 8.

A dielectric layer 20 is disposed between the anode element 1 and the cathode element 2, and the cathode element 2 includes a cathode layer 21, a carbon layer 22, and a silver layer 23, which are sequentially disposed, that is, the dielectric layer 20, the cathode layer 21, the carbon layer 22, and the silver layer 23 are sequentially disposed outside the anode element 1. The silver layer 23 is connected to a cathode silver paste 24. The cathode layer 21 of the cathode element 2 comprises one or more of manganese dioxide, polypyrrole, polythiophene, polyaniline, polyphenylpropylamine and their respective derivatives. That is, the cathode layer 21 may comprise only one component, such as the cathode layer 21 comprising only manganese dioxide, only polythiophene; cathode layer 21 may also comprise two components, e.g. cathode layer 21 comprises polyaniline and polyaniline derivatives; cathode layer 21 may also include three components including, for example, manganese dioxide, polyaniline, and polyphenylpropylamine. Correspondingly, the cathode layer 21 may also comprise four, five or six components. The present application is not limited thereto.

The density of the cathode layer 21 was in the range of 5.0 g/cm^-3～14.0g·cm^-3. When the density of the cathode layer 21 was controlled to 5.0 g/cm^-3～14.0g·cm^-3In between, the ESR value reduction effect is particularly remarkable.

Wherein the anode lead-out wire 5 is connected to the anode element 1. The exterior of the anode lead-out wire 5, the anode element 1 and the cathode element 2 is filled with an encapsulating material 9. The sealing material 9 may be, but not limited to, a plastic sealing resin or a phenol resin. Specifically, the plastic package resin may also be an epoxy plastic package resin.

The substrate 8 is disposed at the bottom of the anode element 1 and the cathode element 2. In the embodiment of the present application, the substrate 8 is provided with an anode connecting groove 10 and a cathode connecting groove 11; an electric conductor is arranged in the anode connecting groove 10 and the cathode connecting groove 11. The conductive body may be, but is not limited to, a conductive silver paste, a conductive ink, and the like. The conductor may also be a conductive paste having adhesiveness, such as Au (elemental gold), Pd (elemental palladium), Ni (elemental nickel), or the like.

An anode bottom terminal 6 disposed at the bottom of the substrate 8 and connected to one side of the anode connecting groove 10; one end of the conductor provided in the anode connecting groove 10 is connected to the anode lead wire 5, and the other end of the conductor provided in the anode connecting groove 10 is connected to the upper surface of the anode bottom surface terminal 6. As shown in fig. 2, the conductor in the anode connecting groove 10 is deposited between the anode lead wire 5 and the upper surface of the anode bottom surface terminal 6. That is, in an actual manufacturing process, when the anode element 1 is fixed to the substrate 8 provided with the anode connecting grooves 10, a conductive body is injected into the anode connecting grooves 10, so that the conductive body in the anode connecting grooves 10 is accumulated to be connected to the anode lead-out wires 5.

A cathode bottom terminal 7 disposed at the bottom of the substrate 8 and connected to one side notch of the cathode connecting groove 11; one end of the conductor provided in the cathode connecting groove 11 is connected to the cathode element 2 (in the drawing, connected to the cathode element 2 through the cathode silver paste 24), and the other end of the conductor provided in the cathode connecting groove 11 is connected to the upper surface of the cathode bottom surface terminal 7. As shown in fig. 2, the conductor in the cathode connecting groove 11 is deposited between the cathode silver paste 24 and the upper surface of the cathode bottom surface terminal 7. That is, in an actual manufacturing process, when the cathode element 2 is fixed to the substrate 8 provided with the cathode connecting grooves 11, a conductor is injected into the cathode connecting grooves 11, so that the conductor in the cathode connecting grooves 11 is accumulated to be connected to the cathode silver paste 24.

The anode lead terminal 3 is connected to an anode lead wire 5 and an anode bottom surface terminal 6. That is, the external connection is formed through the anode tap 3.

Cathode lead 4 is connected to cathode element 2 and cathode bottom terminal 7. That is, the external connection is formed through the cathode lead 4. Specifically, the cathode lead 4 is connected to the cathode element 2 through a cathode silver paste 24.

In the embodiment of the present application, the anode lead 3 and the cathode lead 4 are plated layers, and in particular, the plated layers may be formed by electroplating or chemical plating. When the plating layer is formed by electroless plating, the plating layer is composed of an inner plating layer formed by electroless plating of Ni/P (elemental nickel/elemental phosphorus) and an outer plating layer formed by electroless plating of Au (elemental gold) or Sn (elemental tin).

In order to reduce the manufacturing cost of the surface-mount capacitor 100, the plating layer may be formed by dipping or paste plating.

In summary, in the embodiment of the present application, by providing the anode connecting groove 10 and the cathode connecting groove 11 on the substrate 8, the anode element 1 can be conducted to the anode bottom terminal 6 through the electrical conductor in the anode connecting groove 10, the cathode element 2 can be conducted to the cathode bottom terminal 7 through the electrical conductor in the cathode connecting groove 11, so that two parallel equivalent resistances are formed between the anode element 1 and the anode bottom terminal 6 (one is an internal circuit formed by the electrical conductor in the anode connecting groove 10 connecting the anode element 1 and the anode bottom terminal 6, the other is an external circuit formed by the anode terminal 3), two parallel equivalent resistances are formed between the cathode element 2 and the cathode bottom terminal 7 (one is an internal circuit formed by the electrical conductor in the cathode connecting groove 11 connecting the cathode element 2 and the cathode bottom terminal 7, and the other is an external circuit formed by the cathode terminal 4), thereby reducing the ESR of the surface mount capacitor 100 and improving the reliability of the surface mount capacitor 100.

Referring to fig. 3, in order to ensure that the electrical conductor in the anode connecting groove 10 can effectively communicate with the anode lead-out wire 5 and the anode bottom terminal 6, and the electrical conductor in the cathode connecting groove 11 can effectively communicate with the cathode element 2 and the cathode bottom terminal 7, the electrical conductor is not easily deformed, and optionally, the notch on the other side of the anode connecting groove 10 extends to be connected with the anode lead-out wire 5. The other side notch of the cathode connecting groove 11 extends to be connected with the cathode element 2 (the other side notch of the cathode connecting groove 11 extends to the cathode silver paste 24 to be connected with the cathode element 2).

It should be noted that, the other side notch of the anode connecting groove 10 extends to be connected with the anode lead-out wire 5, and it is understood that a communicating groove is formed between the anode lead-out wire 5 and the anode bottom terminal 6, and the groove passes through the substrate 8 to be connected with the upper surface of the anode bottom terminal 6. In this way, when the conductor is provided in the groove, the conductor can be connected to the upper surfaces of the anode lead-out wire 5 and the anode bottom surface terminal 6, respectively. Similarly, the other side notch of the cathode connecting groove 11 extends to be connected with the cathode element 2, and can be connected to form a communicating groove between the cathode silver paste 24 and the cathode bottom terminal 7, and the communicating groove penetrates through the substrate 8 to be connected with the upper surface of the cathode bottom terminal 7.

Alternatively, the number of the anode connecting grooves 10 formed on the base plate 8 may also be at least two, and correspondingly, the number of the cathode connecting grooves 11 formed on the base plate 8 may also be at least two. For example, referring to fig. 4, another structure of the surface mount capacitor 100 is provided in the embodiments of the present application. The number of the anode connecting grooves 10 formed in the substrate 8 is two, and the number of the cathode connecting grooves 11 formed in the substrate 8 is also two. The electric conductor in the two anode connecting grooves 10 is stacked between the anode lead wire 5 and the upper surface of the anode bottom surface terminal 6. That is, in an actual manufacturing process, when the anode element 1 is fixed to the substrate 8 provided with the two anode connecting grooves 10, the electric conductors are injected into the two anode connecting grooves 10, so that the electric conductors in the anode connecting grooves 10 are stacked to be connected to the anode outgoing line 5; in which the electrical conductors placed above the two anode connecting grooves 10 are stacked together. The electrical conductor in the two cathode connecting grooves 11 is deposited between the cathode silver paste 24 and the upper surface of the cathode bottom terminal 7. That is, in the actual manufacturing process, when the cathode element 2 is fixed on the substrate 8 provided with two cathode connecting grooves 11, the conductive bodies are injected into the two cathode connecting grooves 11, so that the conductive bodies in the cathode connecting grooves 11 are accumulated to be connected with the cathode silver paste 24; in which the electrical conductors placed above the two cathode connecting slots 11 are stacked together.

In this way, three equivalent resistances connected in parallel are formed between the anode element 1 and the anode bottom terminal 6 (two of them are two internal circuits formed by connecting the anode element 1 and the anode bottom terminal 6 through the conductors in the two anode connecting grooves 10, and the third is an external circuit formed by the anode leading-out terminal 3). In this way, three equivalent resistances connected in parallel are formed between the cathode element and the cathode bottom terminal 7 (two of them are two internal circuits formed by the conductors inside the two cathode connecting grooves 11 connecting the cathode element 2 and the cathode bottom terminal 7, and the third is an external circuit formed by the cathode terminal 4).

Of course, in other embodiments, three anode connecting grooves 10 and four cathode connecting grooves 11 may be formed in the base plate 8, or one anode connecting groove 10 and two cathode connecting grooves 11 may be formed in the base plate 8. The number of the anode connecting grooves 10 and the cathode connecting grooves 11 may be equal or unequal, and the application is not limited.

Alternatively, when the number of the anode connecting grooves 10 is at least two, the other side notches of the at least two anode connecting grooves 10 may be extended to be connected with the anode lead-out wires 5. Accordingly, when the number of the cathode connecting grooves 11 is at least two, the other side notches of the cathode connecting grooves 11 may be extended to be connected with the cathode element 2. As shown in fig. 5, the electrical conductors in the two anode connecting slots 10 are separated, and the electrical conductors in the two cathode connecting slots 11 are also separated.

In summary, in the embodiment of the present application, by providing at least two anode connection grooves 10 on the substrate 8 and at least two cathode connection grooves 11 on the substrate 8, a multi-path parallel equivalent resistance is formed between the anode element 1 and the anode bottom terminal 6, and a multi-path parallel equivalent resistance is formed between the cathode element and the cathode bottom terminal 7, so as to further reduce the ESR value of the surface mount capacitor 100, and improve the reliability of the surface mount capacitor 100.

Alternatively, in order to ensure the reliability and rationality of the surface-mount capacitor 100, the area of the sum of the anode connecting grooves 10 and the cathode connecting grooves 11 is 10% to 80% of the area of the sum of the anode bottom surface terminal 6 and the cathode bottom surface terminal 7. For example, the area of the sum of the anode connecting grooves 10 and the cathode connecting grooves 11 is 20%, 70%, etc. of the area of the sum of the anode bottom terminal 6 and the cathode bottom terminal 7. The size of the anode connecting groove 10 and the cathode connecting groove 11 meeting the above conditions can be designed by the skilled person according to the requirement, and the present application is not limited.

As shown in fig. 6, as a configuration of the connection groove, in the embodiment of the present application, the anode connection groove 10 is opened on a side of the substrate 8 close to the anode lead-out terminal 3, and a side of the anode connection groove 10 close to the anode lead-out terminal 3 is opened, so that the anode lead-out terminal 3 is connected to the conductor in the anode connection groove 10; the cathode connecting groove 11 is opened at a side of the substrate 8 close to the cathode lead-out terminal 4, and a side of the cathode connecting groove 11 close to the cathode lead-out terminal 4 is opened so that the cathode lead-out terminal 4 is connected with the electric conductor in the cathode connecting groove 11. By the method, the manufacturing difficulty of the surface-mount capacitor 100 can be reduced, and the overall performance of the surface-mount capacitor 100 is improved. Accordingly, when the number of the anode connecting grooves 10 is two and the number of the cathode connecting grooves 11 is two, it can be referred to as shown in fig. 7. In the actual manufacturing process, when the anode element 1 is fixed on the substrate 8 provided with two anode connecting grooves 10 (one of the anode connecting grooves 10 is opened on the side of the substrate 8 close to the anode leading-out end 3, and the side of the anode connecting groove 10 close to the anode leading-out end 3 is opened), a conductive body is injected into the two anode connecting grooves 10, so that the conductive body in the anode connecting groove 10 is accumulated to be connected with the anode leading-out wire 5; in which the electrical conductors placed above the two anode connecting grooves 10 are stacked together. In the actual manufacturing process, when the cathode element 2 is fixed on the substrate 8 provided with two cathode connecting grooves 11 (one of the cathode connecting grooves 11 is opened on the side of the substrate 8 close to the cathode lead-out end 4, and the side of the cathode connecting groove 11 close to the cathode lead-out end 4 is opened), a conductor is injected into the two cathode connecting grooves 11, so that the conductor in the cathode connecting grooves 11 is accumulated to be connected with the cathode silver paste 24; in which the electrical conductors placed above the two cathode connecting slots 11 are stacked together.

The inventors of the present application have found in their research that a plug-in design is currently used between the anode lead 5 and the anode element 1, which results in the anode lead 5 occupying the effective volume of the anode element 1, thereby reducing the capacity ratio of the surface-mount capacitor 100. Therefore, referring to fig. 8, in the embodiment of the present application, the anode lead 5 is connected to the first surface of the anode element 1. Wherein the first surface is to be understood as a certain side of the anode element 1. By connecting the anode lead-out wire 5 with the first surface of the anode element 1, the anode lead-out wire 5 does not occupy the effective volume of the anode element 1, thereby effectively improving the capacity ratio of the surface mount capacitor 100 and improving the utilization rate of the anode element 1.

As an implementation of the connection, the anode lead-out wire 5 is formed by welding with the first surface of the anode element 1. As another implementation of the connection, the anode lead-out wire 5 is formed by sintering with the first surface of the anode element 1. By adopting the two methods to connect the anode lead-out wire 5 with the surface of the anode element 1, the stable connection between the anode lead-out wire 5 and the anode element 1 can be ensured, and the stability of the surface-packaged capacitor 100 is further improved.

Since the anode lead wire 5 is connected to the first surface of the anode element 1, the position of the anode lead wire 5 can be freely adjusted, that is, the position of soldering or sintering can be freely set in the manufacturing process of the surface-mount capacitor 100. For example, in the present embodiment, the anode lead-out wire 5 is disposed below the center line of the first surface of the anode element 1. By the method, the manufacturing difficulty of the surface packaging capacitor 100 is reduced, the length of the conducting path is reduced, the ESR value of the surface packaging capacitor 100 is reduced, and the overall performance of the surface packaging capacitor 100 is improved.

In order to further improve the internal stability and reliability of the surface-mount capacitor 100, in the embodiment of the present application, the anode lead-out wire 5 has a hetero-structure, rather than a smooth linear structure.

As an embodiment of the first hetero-structure, referring to fig. 9, the anode lead-out wire 5 has a screw structure. It should be explained that the thread refers to a continuous convex portion of a specific section made in a spiral shape on the surface of a cylindrical or conical parent body. The thread is divided into external thread and internal thread according to the position of the parent body, and is divided into triangular thread, rectangular thread, trapezoidal thread, sawtooth thread and other special-shaped threads according to the section shape (tooth shape). In the embodiment of the present application, the parent material is the anode lead wire 5, and the present application is not limited to the specific thread structure. In the embodiment of the application, the anode outgoing line 5 with the threaded structure is adopted, so that the packaging material 9 can be filled into the texture of the anode outgoing line 5 with the threaded structure, the combination area between the anode outgoing line 5 and the packaging material 9 is increased, the combination force between the anode outgoing line 5 and the packaging material 9 is further enhanced, the generation of gaps and the entering of external moisture are prevented, and the reliability of a product is improved.

As an embodiment of the second hetero-structure, referring to fig. 10, the anode lead-out line 5 adopts a zigzag structure. It should be explained that a sawtooth structure is a constructional feature having a sawtooth profile. The surface of the saw blade is in a staggered and continuous integral structure, and equal intervals are formed between every two saw teeth. Through the anode lead wire 5 that adopts the sawtooth structure for among the packaging material 9 can fill the clearance to the anode lead wire 5 of sawtooth structure, increased the bonding area between anode lead wire 5 and the packaging material 9, and then strengthened the cohesion between anode lead wire 5 and the packaging material 9, prevented the production in gap and outside moisture entering, improved the reliability of product.

As an embodiment of the third alternative structure, referring to fig. 11, the diameter of the anode lead-out wire 5 on the side near the anode lead-out terminal 3 is larger than the diameter of the anode lead-out wire 5 on the side near the anode element 1. That is, the diameter of the two ends of the anode outgoing line 5 is different in size, a side is formed at the junction of the two ends with different diameters, in this way, one side is formed at the junction of the two ends with different diameters, so that the area of the anode outgoing line 5 and the anode outgoing line 3 is large, the reliability of connection between the anode outgoing line and the anode outgoing line is improved, and further the ESR value of the surface-packaged capacitor is reduced, and secondly, because the diameters of the two ends of the anode outgoing line 5 are different, and further the bonding area between the anode outgoing line 5 and the packaging material 9 is increased through the side formed at the junction of the two ends with different diameters, and further the bonding force between the anode outgoing line 5 and the packaging material 9 is enhanced, the generation.

As an embodiment of the fourth alternative structure, referring to fig. 12, the diameter of the anode lead-out wire 5 on the side close to the anode lead-out terminal 3 is smaller than the diameter of the anode lead-out wire 5 on the side close to the anode element 1. It will be understood that the anode lead-out wire 5 in fig. 12 is connected in the opposite manner to the anode lead-out wire 5 shown in fig. 11, i.e., the larger diameter end of the anode lead-out wire 5 in fig. 12 is connected to the anode element 1 and the smaller diameter end is connected to the anode lead-out terminal 3. Through the mode, firstly, the anode element 1 and the anode lead-out wire 5 are connected more stably, secondly, the bonding area between the anode lead-out wire 5 and the packaging material 9 is increased, further, the bonding force between the anode lead-out wire 5 and the packaging material 9 is enhanced, the generation of gaps and the entering of external moisture are prevented, and the reliability of products is improved.

The anode lead-out wire 5 having the above-described anisotropic structure is not limited in the present application.

With continued reference to fig. 2, optionally, in order to effectively ensure the short circuit between the conductive body inside the anode connecting groove 10 and the cathode element 2, an insulator 12 is further disposed between the conductive body of the anode connecting groove 10 and the cathode element 2. The insulator may be ceramic, rubber, etc., and the present application is not limited thereto.

A specific application of the surface-mount capacitor 100 described above is described below.

As an application, the anode element 1 is a tantalum block. That is, the surface-mount capacitor 100 described above may be a tantalum capacitor. This will be explained below with reference to comparative example 1.

Comparative example 1:

the goal was to make a 16V 2.2uF conductive polymer tantalum capacitor by pressing and sintering a tantalum powder with a charge of 30000CV/g to form a porous anode with dimensions of 1.2mm length by 0.55mm width by 0.55mm height. The same polyimide material was sprayed onto tantalum wire and cured at 150 degrees for 30 minutes and the anode was oxidized to 50V in phosphoric acid electrolyte.

Using 4 wt% of 3, 4-ethyldioxythiophene monomer, 16 wt% of oxidant, 16 wt% of butanol and 2-propanol as raw materials, preparing an impregnation solution, repeatedly immersing an anode therein, and curing at 85 ℃ for 60 minutes. The anodes were washed in 25 degrees deionized water and dried after each curing cycle, and the anodes were treated as described above.

Carbon and silver are coated on the outside of the anode block, and the coating material and the conductive polymer on the metal wire are removed by a laser cleaning method.

The substrate is provided with no holes, the anode block is directly adhered to the substrate, the substrate is packaged by epoxy resin, and is led out through splints and terminals to form a product with the size of 0.9mm 1.7mm 0.8mm, and finally, the aging sorting test is carried out.

The tantalum capacitor provided in embodiment 1 of the present application: the substrate was laser-engraved with 2 connecting grooves (cathode connecting groove and anode connecting groove, respectively), and a conductive body was filled in both connecting grooves, and then the anode block was bonded to the substrate, and the other procedures were the same as in comparative example 1.

Effect verification example 1: referring to fig. 13, fig. 13 is a circuit diagram for supplying power to a Central Processing Unit (CPU) of a Field Programmable Gate Array (FPGA) according to an embodiment of the present application. The specific circuit parameters are as follows: vin is 12V, Vout is 1V, peak current 40A, slope is 30A/us, switching frequency of the switching power supply is 500kHz (2 phase), inductance is 0.15uH, 150 capacitors of comparative example 1 and 150 capacitors of example 1 of the present application are mounted in a circuit (the capacitors are mounted at positions marked with CAP in the figure), peak-to-peak values of the power supply terminal voltage of the CPU are measured, and the data are shown in table 1.

And (3) data comparison:

the comparative product was tested for ESR (as shown in table 1 below) for a target product, 16V 2.2uF conductive polymer tantalum capacitor:

TABLE 1

As can be seen from the comparison of the data in table 1, the tantalum capacitor provided in example 1 of the present application can significantly reduce the ESR value and reduce the peak-to-peak voltage.

As another application, the anode element 1 described above is an aluminum block. That is, the surface-mount capacitor 100 described above may be an aluminum capacitor. This will be explained below with reference to comparative example 2.

Comparative example 2:

an oxide is formed on an aluminum foil rated to withstand a voltage of 11V, which can produce an aluminum foil having a specific volume of 190uF/cm 2. The aluminum foil was cut into strips of 3.5mm width and welded to the processing strips. A masking layer was applied to form a region of 4.7mmx3.5mm in size for formation.

The aluminum foil was immersed in a pure water solution of 5% by weight of ammonium adipate, and the alumina dielectric layer at the edge of the aluminum foil was repaired by applying a direct current voltage of 11V.

The aluminum foil is dipped in an oxidant aqueous solution prepared by 25 wt% of ammonium persulfate and 1 wt% of sodium toluenesulfonate in sequence under vacuum, and then dipped in 1.5mol/L of a propanol solution of 3, 4-ethyldioxythiophene. The anode was held at 40.5 degrees for 30 minutes to complete the polymerization. The reaction was repeated 3 times from the immersion in the aqueous oxidant solution to the polymerization reaction. The aluminum foil was then cleaned of polymerization byproducts and coated with carbon and silver.

The 8 layers of units are stacked together to form an anode block, the positive end of the anode block is welded by resistance welding, and the negative end of the anode block is adhered together by conductive silver adhesive and is heated and cured.

The substrate has no holes, the anode block is directly adhered to the substrate, the substrate is packaged by epoxy resin, and is led out through splints and terminals to form a product with the size of 7.3mm 4.3mm 1.9mm, and finally, an aging sorting test is carried out.

Embodiment 2 of the present application:

the substrate was engraved with laser 1 hole/terminal and conductive paste was filled in the hole, and then the anode block was bonded to the substrate, and the other flow was the same as in comparative example 2.

Effect verification example 2: with continued reference to fig. 13, the same circuit design and parameter effect verification example 1 is used, but in this verification, only 3 capacitors of comparative example 2 and 3 capacitors of example 2 of the present application are installed in the circuit (the capacitors are installed at the positions marked with CAP in the figure), and the peak-to-peak value of the CPU supply voltage is measured, and the data is listed in table 2.

And (3) data comparison:

the comparative product was tested for ESR (as shown in table 2 below) for a conductive polymer aluminum capacitor of the target product 6.3V 220 uF:

TABLE 2

As can be seen from the comparison of the data in table 2, the aluminum capacitor provided in example 2 of the present application can significantly reduce the ESR value and reduce the peak-to-peak voltage.

Comparative example 3

The substrate uses laser to carve 2 connecting grooves (cathode connecting groove and anode connecting groove respectively), and fills the electric conductor into two connecting grooves, then bonds the anode block to the substrate.

The target product, 16V 2.2uF conductive polymer tantalum capacitor, was tested for moisture resistance of the comparative product according to JEDEC J-STD-020B.

The tantalum capacitor provided in embodiment 3, embodiment 4, and embodiment 5 of the present application is: the anode lead wires were used in fig. 9, 10 and 11, respectively, and the other flow was the same as in comparative example 3.

And (3) data comparison:

TABLE 3

	Anode lead wire pattern	Humidity sensitivity resistant grade
			Comparative example 3	FIG. 8	MSL3
Example 3 of the present application	FIG. 9	MSL2a
			Example 4 of the present application	FIG. 10 shows a schematic view of a	MSL2a
Application example 5	FIG. 11	MSL2a

As can be seen from the comparison of the data in table 3, the tantalum capacitor provided in the embodiment of the present application can significantly improve the moisture resistance of the product.

Referring to fig. 14, based on the same inventive concept, an embodiment of the present application further provides a method for manufacturing a surface mount capacitor, including: step S101-step S105.

Step S101: a substrate is provided.

Step S102: and an anode connecting groove and a cathode connecting groove are formed in the substrate through laser engraving.

Step S103: and filling an electric conductor into the anode connecting groove and the cathode connecting groove.

Step S104: and adhering the prepared anode block to the substrate so that the electric conductor in the anode connecting groove is connected with the anode lead-out wire and the anode bottom surface terminal, and the electric conductor in the cathode connecting groove is connected with the cathode element and the cathode bottom surface terminal.

It should be noted that the process of preparing the anode block includes: the surface of the anode element is connected with an anode lead-out wire; sequentially generating a dielectric layer and a conductive polymer layer (cathode layer) on the surface of the anode element; then continuously coating a carbon layer and a silver layer on the surface; and finally, cleaning the anode lead-out wire and coating an insulator.

For ease of understanding, the preparation process is described below with reference to fig. 15: 1. and (5) manufacturing an anode element. 2. And (4) bonding the anode element with the anode lead wire. 3. And generating the dielectric layer. 4. And generating a cathode layer. 5. The surface is coated with a carbon layer. 6. The surface is coated with a silver layer. 7. An insulator is provided. 8. The anode element is bonded to a substrate processed with anode connecting grooves and cathode connecting grooves. 9. And (4) packaging (injecting a conductor, cathode silver paste, packaging materials and the like). 10. And leading out the terminal.

Specifically, the description of the structure in the method step can refer to the above description of the structure of the surface-mount capacitor, and the description is not repeated here to avoid redundancy.

Step S105: and carrying out packaging test on the anode block.

The encapsulation may be performed by, but not limited to, a plastic encapsulation resin or a phenol resin. And then the split sheet and the terminal are used for leading out, namely leading out through an anode leading-out end and a cathode leading-out end.

The complete surface-packaged capacitor can be formed through the steps, and an aging sorting test method can be adopted for screening subsequently, and the method is not limited in the application.

In the description of the present application, it should be noted that the terms "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the application usually place when using, and are only used for convenience in describing the present application and simplifying the description, but do not indicate or imply that the devices or elements that are referred to must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

It should also be noted that, unless expressly stated or limited otherwise, the terms "disposed" and "connected" are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

The above description is only an example of the present application and is not intended to limit the scope of the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A surface mount capacitor, comprising:

an anode element and a cathode element isolated from each other;

an anode lead line connected to the anode element; the outer parts of the anode lead-out wire, the anode element and the cathode element are filled with packaging materials;

the substrate is arranged at the bottoms of the anode element and the cathode element, and an anode connecting groove and a cathode connecting groove are formed in the substrate; electric conductors are arranged in the anode connecting groove and the cathode connecting groove;

the anode bottom terminal is arranged at the bottom of the substrate and is connected with a side notch of the anode connecting groove; one end of the conductor arranged in the anode connecting groove is connected with the anode leading-out wire, and the other end of the conductor arranged in the anode connecting groove is connected with the upper surface of the anode bottom surface terminal;

the cathode bottom terminal is arranged at the bottom of the substrate and is connected with a side notch of the cathode connecting groove; one end of the conductor arranged in the cathode connecting groove is connected with the cathode element, and the other end of the conductor arranged in the cathode connecting groove is connected with the upper surface of the cathode bottom surface terminal;

an anode lead-out terminal connected to the anode lead-out wire and the anode bottom surface terminal;

and a cathode lead terminal connected to the cathode element and the cathode bottom surface terminal.

2. A surface-mount capacitor according to claim 1 wherein the anode lead is connected to the first surface of the anode element.

3. The surface-mount capacitor according to claim 2, wherein the anode lead-out wire and the first surface of the anode element are formed by welding or sintering.

4. A surface-mount capacitor according to claim 2 wherein the anode lead-out wire is disposed below a centerline of the first surface of the anode element.

5. The surface-mount capacitor as claimed in claim 1, wherein the anode lead-out wire has a screw structure.

6. The surface-mount capacitor of claim 1 wherein the anode lead lines are in a saw-tooth configuration.

7. A surface-mount capacitor as claimed in claim 1, wherein the diameter of the anode lead-out wire on the side near the anode lead-out terminal is larger than the diameter of the anode lead-out wire on the side near the anode element.

8. The surface-mount capacitor of claim 1 wherein the cathode element is disposed on an outer layer of the anode element with a dielectric layer disposed therebetween, the cathode element comprising a cathode layer, a carbon layer, and a silver layer disposed in that order; an insulator is arranged between the conductor in the anode connecting groove and the cathode element.

9. The surface mount capacitor of claim 8 wherein the cathode layer of the cathode element comprises one or more of manganese dioxide, polypyrrole, polythiophene, polyaniline, polyphenylpropylamine, and their respective derivatives.

10. The surface mount capacitor of claim 1, wherein the electrical conductor is a conductive silver paste.

11. The surface-mount capacitor of claim 1 wherein the substrate has at least two anode connecting slots formed therein; the number of the cathode connecting grooves formed in the substrate is at least two.

12. A surface-mount capacitor as claimed in claim 1 wherein the combined area of said anode connection slots and said cathode connection slots is 10% to 80% of the combined area of said anode bottom terminal and said cathode bottom terminal.

13. A surface-mount capacitor as claimed in claim 1, wherein the anode connecting groove is opened at a side of the substrate adjacent to the anode lead, and a side of the anode connecting groove adjacent to the anode lead is opened to connect the anode lead with the electric conductor in the anode connecting groove;

the cathode connecting groove is formed in one side, close to the cathode leading-out end, of the substrate, and is opened in one side, close to the cathode leading-out end, of the cathode connecting groove, so that the cathode leading-out end is connected with the conductor in the cathode connecting groove.

14. A surface-mount capacitor as claimed in claim 1 wherein the other side notch of the anode connection slot extends to connect with the anode lead-out wire; the other side notch of the cathode connecting groove extends to be connected with the cathode element.

15. The surface mount capacitor of claim 1 wherein the anode element is a tantalum block; the cathode element is arranged on the outer layer of the tantalum block, a dielectric layer is arranged between the cathode element and the tantalum block, and the cathode element comprises a cathode layer, a carbon layer and a silver layer which are sequentially arranged.

16. The surface mount capacitor of claim 1 wherein the anode element is an aluminum block; the cathode element is arranged on the outer layer of the aluminum block, a dielectric layer is arranged between the cathode element and the aluminum block, and the cathode element comprises a cathode layer, a carbon layer and a silver layer which are sequentially arranged.

17. A method for manufacturing a surface-mount capacitor includes:

providing a substrate;

forming an anode connecting groove and a cathode connecting groove on the substrate through laser engraving;

filling an electric conductor into the anode connecting groove and the cathode connecting groove;

bonding the prepared anode block on the substrate, so that the electric conductor in the anode connecting groove is connected with the anode lead-out wire and the anode bottom surface terminal, and the electric conductor in the cathode connecting groove is connected with the cathode element and the cathode bottom surface terminal;

and carrying out packaging test on the anode block.