Feed-through capacitor with short-circuit self-protection function

Abstract

The invention relates to a feed-through capacitor with a short-circuit self-protection function, and belongs to the technical field of communication electronics. The feed-through capacitor is of an integral sheet type structure and comprises a shell, a capacitor substrate, a feed-through terminal / lead, a fusing protection device and an encapsulation / sealing material. Another feed-through capacitor is of a multi-chip dispersion structure, comprises a surface-mounted fusing protection device and an embedded fusing protection device, and comprises a shell, a circuit board, a capacitor substrate, a feed-through terminal / lead, a fusing protection device and an encapsulation / sealing material. When the feed-through capacitor breaks down, the feed-through capacitor can play a role in short circuit or over-current fusing, the feed-through capacitor is separated from a ground wire in a whole machine to disconnect a loop, meanwhile, the circuit is kept on, a fault point is separated, and shutdown of the whole machine is reduced.

Description

Technical Field

[0001] This invention belongs to the field of communication electronics technology, and specifically relates to a feedthrough capacitor with short-circuit self-protection function. Background Technology

[0002] Feedthrough capacitors are widely used in anti-interference circuits, filtering circuits, and bypass circuits in communication equipment and electronic devices. Connected between a line and ground, feedthrough capacitors feature high stability, low loss, and low self-inductance; they serve functions such as filtering, bypassing, and decoupling. Common types of capacitors used in capacitor substrates include ceramic dielectric capacitors and film capacitors.

[0003] Currently, due to the requirements of low loss and low self-inductance, feedthrough capacitors and external circuits are connected at multiple points or in a 360° ring to achieve excellent shielding and filtering effects. However, because they are directly connected between the line and ground, damage will cause a short circuit between the line and ground. Feedthrough capacitors themselves have no protection devices, and failure will cause short circuits and shutdowns of the entire equipment. Summary of the Invention (a) Technical problems to be solved The technical problem to be solved by the present invention is how to provide a feedthrough capacitor with short-circuit self-protection function, so as to solve the problem that the feedthrough capacitor itself does not have a protection device and the failure will cause the whole equipment to short-circuit and shut down.

[0004] (II) Technical Solution To solve the above-mentioned technical problems, the present invention proposes a feedthrough capacitor with short-circuit self-protection function. The feedthrough capacitor is an integral chip structure, including: a shell, a capacitor substrate, feedthrough terminals / leads, a fuse protection device, and potting / sealing material. The outer casing is cylindrical with openings at both ends and an internal cavity structure, used to connect the ground electrode of the capacitor; The capacitor substrate can be a single MLCC, tubular ceramic or roll-up film capacitor, connected between the positive terminal and ground. Through-core terminals / leads are used to achieve electrode connections in the circuit. They are located in the center of the housing, pass through the housing, and provide ports for connecting to external circuits at the leads outside the housing. The fuse protection device is located between the capacitor substrate and the bottom surface inside the casing. It is achieved by co-firing a metal fuse on the ceramic capacitor substrate. When a short circuit fault occurs in the feedthrough capacitor, it melts quickly to protect the capacitor substrate. Encapsulation / sealing material is filled inside the housing and above the capacitor substrate to fix and protect the capacitor substrate and fuse protection device inside the housing, forming a reliable fuse gap for the fuse protection device body.

[0005] The present invention also provides a feedthrough capacitor with short-circuit self-protection function. The feedthrough capacitor has a multi-piece distributed structure, including two types: surface-mount fuse protection device and embedded fuse protection device. It includes: shell, circuit board, capacitor substrate, feedthrough terminal / lead, fuse protection device and potting / sealing material. The outer casing is cylindrical with openings at both ends and an internal cavity structure, used to connect the ground electrode of the capacitor; The circuit board, used in a multi-chip distributed structure, is located on the bottom surface inside the housing and is used to solder capacitor substrates and fuse protection devices; it is made of fiberglass cloth or ceramic substrate, with ceramic substrate used when embedding fuse protection devices; The capacitor substrate, located on the circuit board, uses MLCC, tubular ceramic or roll-up film capacitors, and is connected between the positive terminal and ground. Through-core terminals / leads, located at the center of the housing, are used to make electrode connections in the circuit, pass through the housing, and provide ports for connecting to external circuits at the leads outside the housing; The fuse protection device is located between the capacitor substrate and the circuit board ground. When a short circuit fault occurs in the feedthrough capacitor, it melts quickly to protect the capacitor substrate. It is implemented by installing the fuse on the circuit board or by embedding the fuse in the ceramic substrate circuit board. Encapsulation / sealing material is filled inside the housing and above the capacitor substrate to fix and protect the capacitor substrate and fuse protection device inside the housing structure; it forms a reliable fuse gap for the fuse protection device body.

[0006] (III) Beneficial Effects This invention proposes a feedthrough capacitor with short-circuit self-protection function. The feedthrough capacitor proposed in this invention has overcurrent fuse protection function. The protection device is connected between the capacitor and the lead wire through welding, crimping and other methods. When the feedthrough capacitor fails, it can play the role of short circuit or overcurrent fuse, disconnecting the feedthrough capacitor from the ground wire in the whole machine and breaking the circuit. At the same time, the circuit remains conductive, so that the fault point is removed and the downtime of the whole machine is reduced. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of the feedthrough capacitor circuit with protection function of the present invention; Figure 2 This is a schematic diagram of the overall sheet structure assembly of the present invention; Figure 3 A schematic diagram of the assembly of a multi-piece distributed structure (with the fuse protection device built-in); Figure 4 A schematic diagram of the assembly of a multi-chip distributed structure (surface mount fuse protection device); Figure 5The diagram shows the internal layout of the multi-piece distributed structure. (a) is a diagram of the built-in fuse protection device; (b) is a schematic diagram of the dumbbell-shaped front view of the fuse protection device; and (c) is a diagram of the surface-mounted fuse protection device. Figure 6 (a) is a layout diagram of the overall sheet structure; (b) is a schematic diagram of the assembly of the overall sheet structure; and (c) is a schematic diagram of the fuse protection device. Detailed Implementation

[0008] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0009] This invention discloses a feedthrough capacitor with short-circuit self-protection function. Based on the capacitor connection, there are two structural forms: a multi-chip dispersed structure and an integral chip structure. The multi-chip dispersed structure is formed by combining multiple MLCCs, while the integral chip structure uses a single tubular capacitor substrate. It includes several parts: (1) a metal outer shell with open ends in a cylindrical shape, providing protection and support for the internal components; (2) a circuit board, in a disc shape, where components are welded in the multi-chip dispersed structure, serving as the substrate for the fuse protection device. This board can be a fiberglass substrate or a ceramic substrate, and is connected to the capacitor substrate, outer shell, and feedthrough terminals / leads; (3) a capacitor substrate, serving as a filter capacitor. In the integral chip structure, a tubular capacitor substrate is used, while in the multi-chip dispersed structure, multiple ceramic MLCCs are combined; (4) feedthrough terminals / leads, a solid long cylindrical structure. , penetrating the outer shell, with tubular capacitors or circuit boards connected inside the outer shell, and the lead wires of the through-core capacitor outside the outer shell; (5) Fuse protection device, which disconnects when the through-core capacitor experiences a short circuit fault. In the multi-piece dispersed structure, it is achieved by welding the formed fuse, or by embedding a metal fuse body in the ceramic substrate; in the overall sheet structure, it is formed by sintering the fuse wire in low-temperature co-fired ceramic LTCC; (6) Encapsulation / sealing material, which is encapsulated inside the outer shell to fix protection and insulation, and forms a reliable fuse gap for the fuse protection device body after curing.

[0010] The purpose of this invention is to provide a feedthrough capacitor with short-circuit self-protection function. It adopts a multi-stage fuse protection device and an overall fuse protection device to disconnect the capacitor substrate when it is damaged and short-circuited or overcurrent, thereby preventing the whole equipment from short-circuiting and shutting down, and ensuring that the operation of the whole equipment is not affected.

[0011] This invention provides a feedthrough capacitor with short-circuit self-protection function. The feedthrough capacitor has an integral chip structure, including: a shell, a capacitor substrate, feedthrough terminals / leads, a fuse protection device, and potting / sealing material; as shown below. Figure 2 Apply single-chip tubular capacitors; The outer casing is cylindrical with openings at both ends and an internal cavity structure, used to connect the ground electrode of the capacitor; The capacitor substrate uses a single MLCC, tubular ceramic, or roll-up thin film capacitor, connected between the positive terminal and ground. Through-core terminals / leads are used to achieve electrode connections in the circuit. They are located in the center of the housing, pass through the housing, and provide ports for connecting to external circuits at the leads outside the housing.

[0012] The fusible link device rapidly melts and protects the capacitor substrate in the event of a short circuit in the feedthrough capacitor. In the integral chip structure, it is located between the capacitor substrate and the bottom surface of the inner casing, and is implemented using a co-fired metal fusible element on a ceramic substrate. The fusible link device is manufactured using a multilayer ceramic co-fired metal fusible wire in LTCC (Low-Temperature Ceramic Capacitor). An Ag-Pt alloy is screen-printed onto the LTCC green film substrate, with a co-firing temperature of 850℃ and a melting temperature of approximately 900℃.

[0013] Encapsulation / sealing material is filled inside the housing and above the capacitor substrate to fix and protect the capacitor substrate and fuse protection device inside the housing, forming a reliable fuse gap for the fuse protection device body.

[0014] in, The overall chip structure features a monolithic tubular capacitor substrate, using ceramic or organic thin-film dielectric, such as... Figure 6 As shown, the capacitor is coaxially embedded in the housing. The capacitor substrate is tubular, and one of the two annular planes has a positive electrode sintered (or sprayed) on its inner surface, which is connected to the through-core terminal / lead. The other annular plane has an electrode sintered and connected to the first stage of the fuse protection device. In the integral chip structure, the other stage of the fuse protection device is connected to the bottom surface of the housing.

[0015] Through-hole terminals / leads pass through the central axis of the capacitor substrate and extend out of the housing to form output terminals.

[0016] The capacitor has an integral chip structure, with the fuse protection device connected to the capacitor substrate and the casing.

[0017] Encapsulation / sealing material, using epoxy or silicone, is encapsulated inside the housing to keep the through-core terminals / leads coaxial and insulated from the housing.

[0018] The present invention also provides a feedthrough capacitor with short-circuit self-protection function. The feedthrough capacitor has a multi-piece distributed structure, including two types: surface-mount fuse protection device and embedded fuse protection device. It includes: shell, circuit board, capacitor substrate, feedthrough terminal / lead, fuse protection device and potting / sealing material. The outer casing is cylindrical with openings at both ends and an internal cavity structure, used to connect the ground electrode of the capacitor; The circuit board, used in a multi-chip distributed structure, is located on the bottom surface inside the housing and is used to solder capacitor substrates and fuse protection devices. It is made of fiberglass cloth or a ceramic substrate. A ceramic substrate is used when embedding fuse protection devices. The capacitor substrate, located on the circuit board, uses MLCC, tubular ceramic, and roll-up film capacitors, and is connected between the positive terminal and ground. Through-core terminals / leads, located at the center of the housing, are used to make electrode connections in the circuit, pass through the housing, and provide ports for connecting to external circuits at the leads outside the housing.

[0019] A fuse protection device, located between the capacitor substrate and the circuit board ground, can quickly melt and protect the capacitor substrate when a short circuit fault occurs in the feedthrough capacitor. In a multi-chip distributed structure, a typical fuse is installed on the circuit board, or the fuse can be built into the ceramic substrate circuit board.

[0020] Encapsulation / sealing material is filled inside the casing and above the capacitor substrate to fix and protect the capacitor substrate and fuse protection device within the casing. It forms a reliable fusible gap for the fuse protection device body.

[0021] Among them, in the form of multi-piece dispersed structure, such as Figure 3 The capacitor substrate uses multiple MLCC ceramic capacitors, which are distributed in rings on the circuit board, such as... Figure 3-5 As shown.

[0022] The circuit board is circular, with its coaxial center embedded inside the casing, such as... Figure 3 , 4 As shown, the circuit board uses two layers. The inner ring of the top layer is the positive electrode, and the outer ring is the ground electrode, where components are soldered. The bottom layer is the ground electrode and is crimped or soldered to the inner wall of the bottom surface of the outer casing. The ground electrode on the front side of the circuit board is connected to the back electrode. In a multi-layered dispersed structure, Figure 5 As shown, multiple multilayer ceramic capacitors (MLCCs) are dispersed and soldered on the circuit board. The combination of multiple MLCCs forms a ring capacitor structure. One end of the two electrodes of the MLCC is connected to the positive electrode of the circuit board, and the other end is connected to the fuse protection device. The fuse protection device is soldered to the circuit board or embedded in the circuit board and connected to the outer ring ground electrode of the circuit board.

[0023] The through-hole terminal / lead passes through the central axis of the capacitor substrate and extends out of the housing to form the output terminal.

[0024] In a multi-chip distributed structure, the fuse protection device is either individually soldered onto the circuit board or co-fired inside the circuit board, connecting the capacitor substrate and the outer ring ground electrode of the circuit board. The potting / sealing material is made of epoxy or silicone and is encapsulated inside the housing to keep the through-core terminals / leads coaxial and insulated from the housing.

[0025] Example 1: This invention proposes a feedthrough capacitor with its own protection device, the purpose of which is to provide overcurrent fuse protection for the feedthrough capacitor, and to disconnect the fault point in the event of a fault. The implementation scheme includes: (1) The feedthrough capacitor circuit of the present invention consists of a capacitor substrate and a fuse protection device. The capacitor substrate has a feedthrough structure; for example... Figure 1 As shown in the circuit diagram, the fuse protection device is connected to the ground potential location in the circuit and has a low voltage. In the structure, it is connected to the casing to achieve the ground potential.

[0026] (2) The capacitor substrate is assembled using a multi-layer distributed structure, such as... Figure 4 , 5 The following describes a 10A feedthrough capacitor with an outer diameter of 20mm, implemented as follows: (21) The capacitor substrate adopts the surface mount form of multiple ceramic capacitors MLCC on the circuit board. Each MLCC can be 0805 packaged, with a voltage of 100VDC and a capacitance of 1nF~100nF. Multiple ceramic capacitor substrates MLCC are soldered on the circuit board to form a near 360° ring connection, providing multiple ring grounding points.

[0027] (twenty two) Figure 5 The system uses four MLCCs. In practice, at least two MLCC substrates are soldered together. If one MLCC substrate fails and melts, the other MLCC substrates can continue to work.

[0028] (23) The number of ceramic capacitor substrates can be increased to dozens, and they are uniformly welded and arranged on the substrate. Through the coaxiality of the structure and the uniform arrangement, good insertion loss characteristics are maintained.

[0029] (24) The first type of fuse protection device can be made by surface-mount soldering a 0603 surface-mount packaged fuse on the circuit board.

[0030] Method two: The fuse protection device can be made by co-firing the fuse element into the circuit board, such as... Figure 5 The internal layout of the multi-layer distributed capacitor substrate is shown in the diagram. The feedthrough capacitor has an operating current of 10mA or less, and the fuse protection limit is 1A, suitable for use in a 24V DC system. The fuse protection device is made of tin-bismuth alloy (Sn-Bi) to provide overcurrent protection. The tin-bismuth alloy (Sn-Bi) has a sintering temperature below 150℃. The fuse protection device is sintered after the MLCC capacitor is soldered. The sintering temperature is 125℃.

[0031] (25) The fuse protection device is embedded in the circuit board, which is made of ceramic material. First, a melt groove is pre-reserved on the ceramic circuit board, with a width of 200-500μm, a depth of 50μm, and a length of 1-2mm, and the bottom surface is flat; a dumbbell-shaped area with a reduced cross-sectional area is set in the middle, and the ratio of the reduced area to the cross-section of the main body is 0.2-0.5. The melt groove is laser-grooved; Figure 5 (b) A schematic diagram of the dumbbell-shaped front view of the fuse protection device.

[0032] (26) Metallize the bottom of the slot on the circuit board, and after metallization, screen print a 5-30μm thick metal paste, tin-bismuth Sn-Bi alloy; use reflow soldering to melt the metal paste into the corresponding shape and fuse it with the slot on the circuit board; after soldering, use laser to trim.

[0033] (3) Assembled using an integral piece-type structure, such as Figure 6 The diagram shows a 10A feedthrough capacitor with an outer diameter of 20mm. The specific implementation is as follows: (31) The overall structure consists of a housing, through-core terminals / leads, a fuse protection device connected to the housing and capacitor substrate, and potting / sealing materials.

[0034] (32) The fusible protection device is a through-hole circular ring structure, which is manufactured by a circular LTCC multilayer ceramic co-fired metal fusible wire. Multiple Ag-Pt alloys, each 2-3 mm long, are screen-printed on the LTCC green film substrate. They are bent in a serpentine pattern and laser-trimmed. The line width is 50 μm, the resistance is 20-30 mΩ, the fusing point is 2A, and the open circuit resistance after fusing is >1 MΩ. The co-firing temperature is 850℃, and the fusing temperature during use is about 900℃.

[0035] (33) LTCC uses a multi-via structure, such as Figure 6 (b) To achieve connection with the capacitor substrate and the casing, the via diameter is 0.2-0.5mm. After the overcurrent is cut off, a hemispherical metal ball is formed on the surface of the molten metal. The spherical crown-shaped melt is stored in the via, forming a break point.

[0036] Example 2: A feedthrough capacitor with short-circuit self-protection function, characterized in that it comprises: (1) Outer shell (2) Circuit board (3) Capacitor substrate, C (4) Through-core terminal / lead wire (5) Fuse protection device, R (6) Potting / sealing materials (1) The housing provides a through-hole structure and provides housing protection for the internal components.

[0037] (2) Circuit board, used in multi-chip distributed structures, to connect the electrodes of capacitors to the lead electrodes. The circuit board design should be based on the specific circuit requirements, and co-fired ceramics should be used.

[0038] (3) The capacitor substrate can be a single integral chip or a combination of multiple chips.

[0039] (4) Through-hole terminal / lead, solid long cylindrical structure, penetrating the outer shell, with tubular capacitors or circuit boards connected inside the outer shell, and the lead wires of the through-hole capacitors on the outside of the outer shell. (5) The fuse protection device can adopt an integral plate structure or a decentralized protection structure, and can be implemented by co-firing a metal fuse on a co-fired ceramic substrate; it can also be implemented by installing a typical fuse on a circuit board.

[0040] (6) Encapsulation material: used to fix and protect the capacitor substrate and fuse protection device inside the casing.

[0041] Furthermore, the fuse protection device can adopt a built-in fuse element co-fired molding, with a fuse protection limit of 1A. When used in a DC system, a tin-bismuth alloy is applied to provide overcurrent protection.

[0042] The fusible protection device undergoes low-temperature ceramic LTCC co-firing. A melt tank is pre-reserved on the ceramic substrate, with a dumbbell-shaped area with a reduced cross-sectional area in the middle. The melt tank is laser-grooved. The bottom of the tank is metallized, and after metallization, a thick metal slurry of tin-bismuth Sn-Bi alloy is screen-printed. Reflow soldering is used to melt the metal slurry into the corresponding shape and fuse it with the two end stages.

[0043] It adopts an integral chip structure assembly, consisting of one stage of the capacitor substrate connected to leads, and another stage connected to a fuse protection device. The fuse protection device is connected to the outer casing in another stage. It is manufactured by screen printing Ag-Pt alloy onto an LTCC green film substrate; the co-firing temperature is 850℃, and the melting temperature is approximately 900℃.

[0044] The feedthrough capacitor proposed in this invention has an overcurrent fuse protection function. The protective device is connected between the capacitor and the lead wire through welding, crimping and other methods. When the feedthrough capacitor fails, it can play the role of short circuit or overcurrent fuse, disconnecting the feedthrough capacitor from the ground wire in the whole machine and breaking the circuit. At the same time, the circuit remains conductive, so that the fault point is removed and the downtime of the whole machine is reduced.

[0045] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A feedthrough capacitor with short-circuit self-protection function, characterized in that, The feedthrough capacitor has an integral chip structure, including: a shell, a capacitor substrate, feedthrough terminals / leads, a fuse protection device, and potting / sealing material; The outer casing is cylindrical with openings at both ends and an internal cavity structure, used to connect the ground electrode of the capacitor; The capacitor substrate can be a single MLCC, tubular ceramic or roll-up film capacitor, connected between the positive terminal and ground. Through-core terminals / leads are used to achieve electrode connections in the circuit. They are located in the center of the housing, pass through the housing, and provide ports for connecting to external circuits at the leads outside the housing. The fuse protection device is located between the capacitor substrate and the bottom surface inside the casing. It is achieved by co-firing a metal fuse on the ceramic capacitor substrate. When a short circuit fault occurs in the feedthrough capacitor, it melts quickly to protect the capacitor substrate. Encapsulation / sealing material is filled inside the housing and above the capacitor substrate to fix and protect the capacitor substrate and fuse protection device inside the housing, forming a reliable fuse gap for the fuse protection device body.

2. The feedthrough capacitor with short-circuit self-protection function as described in claim 1, characterized in that, The capacitor substrate is a single tubular structure with ceramic or organic thin film dielectric, coaxially embedded in the outer shell. The capacitor substrate is tubular, with a positive electrode sintered on the inner surface of one of the two annular planes, which is connected to the through-core terminal / lead; the other annular plane has an electrode sintered on it, which is connected to the first stage of the fuse protection device; the other stage of the fuse protection device is connected to the bottom surface of the outer shell.

3. The feedthrough capacitor with short-circuit self-protection function as described in claim 1, characterized in that, Encapsulation / sealing material, using epoxy or silicone, is encapsulated inside the housing to keep the through-core terminals / leads coaxial and insulated from the housing.

4. The feedthrough capacitor with short-circuit self-protection function as described in claim 1, characterized in that, The fusible protection device is manufactured by using LTCC multilayer ceramic co-fired metal fusible wire. Ag-Pt alloy is screen-printed on the LTCC green film substrate. The co-firing temperature is 850℃ and the fusing temperature is 900℃.

5. The feedthrough capacitor with short-circuit self-protection function as described in claim 4, characterized in that, The fusible link protection device is a through-ring structure, manufactured using a circular LTCC multilayer ceramic co-fired metal fusible wire. Multiple Ag-Pt alloys, each 2-3 mm long, are screen-printed onto the LTCC green film substrate, exhibiting a serpentine trajectory. Laser trimming is used, resulting in a linewidth of 50 μm, a resistance of 20-30 mΩ, a fusing point of 2A, and an open-circuit resistance >1 MΩ after fusing. The co-firing temperature is 850℃, and the fusing temperature during use is 900℃. The LTCC connects to the capacitor substrate and casing via a multi-via structure with a via diameter of 0.2-0.5 mm. After overcurrent fusing, a hemispherical metal sphere forms on the molten metal surface, and the spherical cap-shaped melt is stored in the via, forming the break point.

6. A feedthrough capacitor with short-circuit self-protection function, characterized in that, The feedthrough capacitor has a multi-layer dispersed structure, including two types: surface-mount fuse protection device and embedded fuse protection device. It includes: shell, circuit board, capacitor substrate, feedthrough terminals / leads, fuse protection device and potting / sealing material; The outer casing is cylindrical with openings at both ends and an internal cavity structure, used to connect the ground electrode of the capacitor; The circuit board, used in a multi-chip distributed structure, is located on the bottom surface inside the housing and is used to solder capacitor substrates and fuse protection devices; it is made of fiberglass cloth or ceramic substrate, with ceramic substrate used when embedding fuse protection devices; The capacitor substrate, located on the circuit board, uses MLCC, tubular ceramic or roll-up film capacitors, and is connected between the positive terminal and ground. Through-core terminals / leads, located at the center of the housing, are used to make electrode connections in the circuit, pass through the housing, and provide ports for connecting to external circuits at the leads outside the housing; The fuse protection device is located between the capacitor substrate and the circuit board ground. When a short circuit fault occurs in the feedthrough capacitor, it melts quickly to protect the capacitor substrate. It is implemented by installing the fuse on the circuit board or by embedding the fuse in the ceramic substrate circuit board. Encapsulation / sealing material is filled inside the housing and above the capacitor substrate to fix and protect the capacitor substrate and fuse protection device inside the housing structure; it forms a reliable fuse gap for the fuse protection device body.

7. The feedthrough capacitor with short-circuit self-protection function as described in claim 6, characterized in that, The circuit board is circular, with its coaxial center embedded inside the outer casing. The circuit board uses two layers: the inner ring of the top layer serves as the positive electrode, and the outer ring serves as the ground electrode, where components are soldered; the bottom layer serves as the ground electrode and is crimped or soldered to the inner wall of the bottom surface of the outer casing. The ground electrode on the front side of the circuit board is connected to the electrode on the back side.

8. The feedthrough capacitor with short-circuit self-protection function as described in claim 7, characterized in that, Multiple MLCCs are dispersed and soldered on the circuit board. The combination of multiple MLCCs forms a ring capacitor structure. One end of the two electrodes of the MLCC is connected to the positive electrode of the circuit board, and the other end is connected to the fuse protection device. The fuse protection device is soldered to the circuit board or embedded in the circuit board and connected to the outer ring ground electrode of the circuit board.

9. The feedthrough capacitor with short-circuit self-protection function as described in claim 6, characterized in that, The manufacturing method of surface-mounted fuse protection device is as follows: The capacitor substrate uses two or more MLCCs in a surface mount form on the circuit board. Multiple MLCCs are soldered on the circuit board to form a near 360° ring connection, providing multiple ring grounding points. The fusible protection device is made by surface-mount soldering a 0603 surface-mount packaged fuse onto a circuit board, or by co-firing a fuse element built into the circuit board. The fusible protection device is made of tin-bismuth alloy Sn-Bi and provides overcurrent protection.

10. The feedthrough capacitor with short-circuit self-protection function as described in claim 6, characterized in that, The manufacturing method of the embedded fuse protection device is as follows: The fuse protection device is embedded in the circuit board, which is made of ceramic material. First, a melt groove is reserved on the ceramic circuit board, with a width of 200-500μm, a depth of 50μm, and a length of 1-2mm, and the bottom surface is flat. A dumbbell-shaped area with a reduced cross-sectional area is set in the middle, and the ratio of the reduced area to the cross-section of the main body is 0.2-0.

5. The melt groove is laser-grooved. Metallize the bottom of the slot on the circuit board, and then screen print a 5-30μm thick metal paste, tin-bismuth Sn-Bi alloy. Reflow soldering is used to melt the metal slurry into the corresponding shape and fuse it with the slots in the circuit board; after soldering, laser finishing is used.

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