Power supply filter and preparation process of power supply filter

Abstract

The invention provides a power supply filter and a preparation process of the power supply filter, and relates to the technical field of filters, the power supply filter comprises a shell and a filtering assembly, the shell is provided with an accommodating cavity, and the filtering assembly is arranged in the accommodating cavity; the filtering assembly comprises a circuit board, a common mode inductor, a differential mode capacitor and a common mode capacitor, the common mode inductor, the differential mode capacitor and the common mode capacitor are all electrically connected to the circuit board, the circuit board is provided with a mounting hole, and the common mode inductor is located in the mounting hole; the common mode inductor and the differential mode inductor are arranged on the peripheral side of the mounting hole in a surrounding mode. By arranging the mounting hole in the circuit board and embedding the common mode inductor into the mounting hole, compared with the mode that the common mode inductor is directly mounted on the surface of one side of the circuit board, the size of the whole filtering assembly can be effectively reduced, and structural optimization and application of the power supply filter are facilitated.

Description

Technical Field

[0001] The present application belongs to the technical field of filters, and more specifically, relates to a power supply filter and a preparation process of the power supply filter. Background Art

[0002] A power filter is a device used to reduce electromagnetic interference in electronic equipment. It improves the performance and stability of electronic equipment by filtering out high-frequency noise on the power line. The power filter is usually installed at the power input end, which can effectively suppress the noise introduced by the power line while allowing the required DC or low-frequency AC to pass smoothly and maintain the stable operation of the power module.

[0003] At present, the filter assembly of the power filter is composed of a circuit board, an inductor arranged on the circuit board, and a capacitor arranged on the circuit board. The inductor is composed of a magnetic core and a coil wound thereon. The coil is usually wound on the magnetic core in multiple layers, which makes the inductor larger in size. Since the inductor is directly welded on the surface of the circuit board, the thickness of the entire filter assembly is increased, which makes it difficult to reduce the overall thickness of the power filter, limiting the structural design and application of the power filter. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a power filter and a manufacturing process of the power filter, so as to solve the defect in the prior art that the inductor is large in size and it is difficult to reduce the thickness of the power filter.

[0005] To achieve the above-mentioned objectives, in a first aspect, the present application provides a power supply filter, comprising a housing and a filter component, the housing having a housing cavity, the filter component being arranged in the housing cavity; the filter component comprising a circuit board, a common-mode inductor, a differential-mode capacitor and a common-mode capacitor, the common-mode inductor, the differential-mode capacitor and the common-mode capacitor are all electrically connected to the circuit board, the circuit board is provided with a mounting hole, the common-mode inductor is located in the mounting hole.

[0006] In some embodiments, the common-mode inductors are provided with two, and the two common-mode inductors include a first common-mode inductor and a second common-mode inductor, the first common-mode inductor includes a first magnetic core and two first coils wound on the first magnetic core; the second common-mode inductor includes a second magnetic core and two second coils wound on the second magnetic core; the two first coils correspond to the two second coils one by one, and the output end of the first coil is connected to the input end of the corresponding second coil;

[0007] The differential mode capacitors are provided with three, and the three differential mode capacitors include: a first differential mode capacitor, a second differential mode capacitor and a third differential mode capacitor; one end of the first differential mode capacitor is connected to the input end of one of the first coils, and the other end is connected to the input end of another of the first coils; one end of the second differential mode capacitor is connected to the output end of one of the first coils, and the other end is connected to the output end of another of the first coils; one end of the third differential mode capacitor is connected to the output end of one of the second coils, and the other end is connected to the output end of another of the second coils;

[0008] There are four common-mode capacitors, and the four common-mode capacitors include: a first common-mode capacitor, a second common-mode capacitor, a third common-mode capacitor and a fourth common-mode capacitor; a first end of the first common-mode capacitor is connected to an output end of one of the first coils, a second end of the first common-mode capacitor is connected to a first end of the second common-mode capacitor, a second end of the second common-mode capacitor is connected to an output end of another of the first coils, and a connection point between the first common-mode capacitor and the second common-mode capacitor is grounded; a first end of the third common-mode capacitor is connected to an output end of one of the second coils, a second end of the third common-mode capacitor is connected to a first end of the fourth common-mode capacitor, a second end of the fourth common-mode capacitor is connected to an output end of another of the second coils, and a connection point between the third common-mode capacitor and the fourth common-mode capacitor is grounded.

[0009] In some embodiments, there are two mounting holes, the two mounting holes include a first mounting hole and a second mounting hole, the first mounting hole and the second mounting hole are arranged at intervals on the circuit board, the first common-mode inductor is installed in the first mounting hole, and the second common-mode inductor is installed in the second mounting hole.

[0010] In some embodiments, the first differential mode capacitor and the second differential mode capacitor are arranged around the first mounting hole; the third differential mode capacitor, the first common mode capacitor, the second common mode capacitor, the third common mode capacitor and the fourth common mode capacitor are arranged together around the second mounting hole.

[0011] In some embodiments, it also includes a positive input terminal, a positive output terminal, a negative input terminal and a negative output terminal arranged on the shell, the positive output terminal is connected to the input end of one of the first coils, and the positive output terminal is connected to the input end of the other first coil; the negative input terminal is connected to the output end of one of the second coils, and the negative output terminal is connected to the output end of the other second coil.

[0012] In some embodiments, it also includes a ground terminal arranged on the housing; the ground terminal is connected to the connection point of the first common-mode capacitor and the second common-mode capacitor and / or the connection point of the third common-mode capacitor and the fourth common-mode capacitor.

[0013] In some embodiments, the housing includes a shell and a cover plate, the shell has an opening, the cover plate is connected to the opening of the shell and covers the opening, and the accommodating cavity is formed between the shell and the cover plate.

[0014] In some embodiments, the housing further includes at least one fixing plate, and the fixing plate is disposed on a side of the shell or the cover plate facing away from the accommodating cavity.

[0015] In some embodiments, potting glue is also included, and the potting glue is filled in the accommodating cavity to encapsulate the filter component in the accommodating cavity.

[0016] On the other hand, the present application provides a preparation process of a power supply filter, the power supply filter is the power supply filter described in the first aspect and any optional embodiment thereof, and the preparation process comprises:

[0017] A mounting hole is formed on the circuit board, and a detachable supporting component is arranged in the mounting hole;

[0018] Put the common mode inductor into the mounting hole and place it on the supporting assembly;

[0019] Soldering the common-mode inductor on the circuit board and removing the supporting assembly;

[0020] Soldering the differential mode capacitor and the common mode capacitor on the circuit board, so that the circuit board, the common mode inductor, the differential mode capacitor and the common mode capacitor constitute the filter component;

[0021] The filter assembly is installed in the accommodating cavity of the housing.

[0022] The beneficial effect of the power supply filter and the preparation process of the power supply filter provided in the present application is that by setting a mounting hole on the circuit board and embedding the common-mode inductor into the mounting hole, compared with directly installing the common-mode inductor on one side surface of the circuit board, the volume of the entire filter component can be effectively reduced, so that the size of the power supply filter can be further reduced, which is beneficial to the structural optimization and application expansion of the power supply filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 This is a schematic diagram of the structure of the power supply filter in the embodiment of the present application;

[0025] Figure 2 is a cross-sectional view of a power filter in an embodiment of the present application;

[0026] Figure 3 An exploded diagram of a power filter in an embodiment of the present application;

[0027] Figure 4 This is a schematic diagram of the structure of the filter assembly in the embodiment of the present application;

[0028] Figure 5 is a circuit diagram of a filter circuit in an embodiment of the present application;

[0029] Figure 6 This is a structural schematic diagram of positioning a common-mode inductor in a mounting hole through a supporting component during the process of preparing a power filter in an embodiment of the present application;

[0030] Figure 7 This is a partial cross-sectional view of positioning the common-mode inductor in the mounting hole through the support assembly during the process of preparing the power filter in an embodiment of the present application.

[0031] Among them, the reference numerals in the figure are:

[0032] 100-housing; 101-accommodating cavity; 110-housing; 111-positive input terminal; 112-negative input terminal; 113-positive output terminal; 114-negative output terminal; 120-cover plate; 130-fixing plate;

[0033] 200-filter component; 210-circuit board; 211-mounting hole; 211a-first mounting hole; 211b-second mounting hole; 212-positive input contact; 213-negative input contact; 214-positive output contact; 215-negative output contact; 216-ground contact; 220-common mode inductor; 230-differential mode capacitor; 240-common mode capacitor;

[0034] 300-filling glue;

[0035] 400-support assembly; 410-base; 411-cavity; 412-slideway; 420-fixed splint; 421-positioning part; 430-movable splint; 431-guide block; 440-screw rod; 441-slider;

[0036] L1-first common mode inductor; L2-second common mode inductor; C1-first differential mode capacitor; C2-second differential mode capacitor; C3-third differential mode capacitor; C4-first common mode capacitor; C5-second common mode capacitor; C6-third common mode capacitor; C7-fourth common mode capacitor. DETAILED DESCRIPTION

[0037] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0038] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0039] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0040] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0041] In a first aspect, the present application provides a power supply filter, such as Figure 1 , Figure 2 and Figure 3As shown, the power supply filter includes a shell 100 and a filter component 200, the shell 100 has a accommodating cavity 101, and the filter component 200 is arranged in the accommodating cavity 101; the filter component 200 includes a circuit board 210, a common-mode inductor 220, a differential-mode capacitor 230 and a common-mode capacitor 240, the common-mode inductor 220, the differential-mode capacitor 230 and the common-mode capacitor 240 are all electrically connected to the circuit board 210, the circuit board 210 is provided with a mounting hole 211, and the common-mode inductor 220 is located in the mounting hole 211.

[0042] The housing 100 is a hollow shell 110 structure. A receiving cavity 101 for installing the filter assembly 200 is formed inside the housing 100 to protect the filter assembly 200. The housing 100 and the receiving cavity 101 can be in a rectangular shape, or can be designed into other shapes according to the shape of the filter assembly 200 and installation requirements. The housing 100 can be made of metal materials, such as aluminum alloy, alloy steel, iron-nickel alloy, etc., to have good heat dissipation and structural strength. In addition, the outer side wall and the inner side wall of the housing 100 can be provided with an electroplated nickel layer, so that the housing 100 has good corrosion resistance and plays an electromagnetic shielding role.

[0043] In some embodiments, the housing 100 may include a housing 110 and a cover plate 120, wherein the housing 110 has an opening, the cover plate 120 is connected to the opening of the housing 110 and covers the opening, and a receiving chamber 101 is formed between the housing 110 and the cover plate 120. When assembling the power filter, the filter assembly 200 may be first buckled into the housing 110 through the opening on the housing 110, and then the cover plate 120 may be connected to the top of the housing 110, so that the cover plate 120 covers the opening of the housing 110, and the filter assembly 200 is enclosed in the receiving chamber 101 formed between the housing 110 and the cover plate 120. Among them, the housing 110 and the cover plate 120 may both be made of an iron-nickel alloy, and the cover plate 120 may be fixed to the opening of the housing 110 by welding, so that the connection between the cover plate 120 and the housing 110 has a high mechanical welding performance. Of course, the housing 110 and the cover plate 120 may also be connected and fixed by bonding or fastener connection.

[0044] In some embodiments, the housing 100 may further include at least one fixing plate 130, which is disposed on the side of the housing 110 or the cover plate 120 facing away from the accommodating cavity 101. For example, the fixing plate 130 is disposed on the outer surface of the housing 110 facing away from the cover plate 120, the fixing plate 130 is perpendicular to the lower surface of the housing 110, and the number of the fixing plates 130 is two and they are respectively located on the two long sides of the housing 110. The fixing plate 130 is used to provide connection and positioning when the housing 100 is connected to an external structure, so as to facilitate the installation and use of the power filter.

[0045] The filter assembly 200 is used to form a filter circuit, and the filter circuit is used to suppress high-frequency common-mode noise. In the filter assembly 200, the circuit board 210 can be a printed circuit board 210, and the base layer of the circuit board 210 can be selected from a high-temperature resistant glass fiber board, and the melting temperature is as high as 400°C, which can adapt to long-term work in high temperature, high humidity and mold environment. The circuit board 210 provides an installation position for the common-mode inductor 220, the differential-mode capacitor 230 and the common-mode capacitor 240, and a circuit pattern is provided on the circuit board 210. The common-mode inductor 220, the differential-mode capacitor 230 and the common-mode capacitor 240 are connected to each other by the circuit pattern to form a filter circuit. When the filter assembly 200 is installed in the accommodating cavity 101, the circuit board 210 can be connected and fixed to the inner wall of the housing 110 by bonding, welding or fastener connection, so as to maintain the stability of the circuit board 210 during use.

[0046] The common-mode inductor 220 includes a magnetic ring and two coils wound around the magnetic ring. The two coils are wound in the same direction so that the current passes through the two coils in the same direction. Since the magnetic fluxes generated by the two coils on the magnetic ring cancel each other, the common-mode inductor 220 has a very small impedance to the differential mode signal, but exhibits a higher impedance to the common mode signal, thereby suppressing the common-mode noise. Among them, the magnetic ring can be a high-permeability manganese-zinc magnetic ring with a high initial permeability and high inductance performance over the entire wide frequency band. The coil can be formed by winding a double-strand enameled copper wire. On the premise of meeting the current flow requirements, the overall height of the common-mode inductor 220 can be reduced, and the installation volume of the common-mode inductor 220 can be reduced. The number of common-mode inductors 220 can be set to one or more. For example, two common-mode inductors 220 are arranged on the circuit board 210, and the two common-mode inductors 220 are connected in series to filter and reduce the noise of the current twice.

[0047] The differential mode capacitor 230 and the common mode capacitor 240 are both used to connect between the two coils in the common mode inductor 220. The differential mode capacitor 230 is used to suppress differential mode interference, and the common mode capacitor 240 is used to suppress common mode interference, so as to isolate the differential mode interference and the common mode interference respectively, and the common mode inductor 220 has a filtering effect.

[0048] The circuit board 210 is provided with a mounting hole 211, which is a through hole that penetrates the circuit board 210. The shape of the mounting hole 211 can be circular or other shapes, and the size of the mounting hole 211 should be larger than the outer diameter of the common-mode inductor 220, so that the common-mode inductor 220 can be located inside the mounting hole 211. When there are multiple common-mode inductors 220, the circuit board 210 can be provided with mounting holes 211 with the same number as the common-mode inductors 220, so that each common-mode inductor 220 is respectively installed in a corresponding mounting hole 211. In addition, a mounting hole 211 with a larger size can be provided on the circuit board 210 to accommodate multiple common-mode inductors 220 at the same time. After the common-mode inductor 220 is placed in the mounting hole 211, the coil of the common-mode inductor 220 can be welded on the circuit board 210, so that the coil is connected to the circuit pattern on the circuit board 210 on the one hand, and the common-mode inductor 220 is supported in the mounting hole 211 by the connection between the coil and the circuit board 210 on the other hand. Furthermore, adhesive may be used to adhere the common-mode inductor 220 to the mounting hole 211 to keep the relative position of the common-mode inductor 220 and the circuit board 210 stable.

[0049] The power filter provided in the embodiment of the present application sets the common-mode inductor 220 in the mounting hole 211 of the circuit board 210 so that the axial center part of the common-mode inductor 220 is located in the hole, and the two ends protrude from the two side surfaces of the circuit board 210 respectively. Compared with installing the common-mode inductor 220 on one side surface of the circuit board 210, the thickness of the filter component 200 can be effectively reduced, which helps to reduce the size of the housing 100, and further reduce the volume of the entire power filter, so as to facilitate the structural optimization and application of the power filter.

[0050] like Figure 4 and Figure 5 As shown, in some embodiments, two common-mode inductors 220 are provided, and the two common-mode inductors 220 include a first common-mode inductor L1 and a second common-mode inductor L2. The first common-mode inductor L1 includes a first magnetic core and two first coils wound on the first magnetic core; the second common-mode inductor L2 includes a second magnetic core and two second coils wound on the second magnetic core; the two first coils correspond to the two second coils one by one, and the output end of the first coil is connected to the input end of the corresponding second coil.

[0051] There are three differential mode capacitors 230, including: a first differential mode capacitor C1, a second differential mode capacitor C2 and a third differential mode capacitor C3; one end of the first differential mode capacitor C1 is connected to the input end of one first coil, and the other end is connected to the input end of another first coil; one end of the second differential mode capacitor C2 is connected to the output end of one first coil, and the other end is connected to the output end of another first coil; one end of the third differential mode capacitor C3 is connected to the output end of one second coil, and the other end is connected to the output end of another second coil.

[0052] There are four common-mode capacitors 240, and the four common-mode capacitors 240 include: a first common-mode capacitor C4, a second common-mode capacitor C5, a third common-mode capacitor C6 and a fourth common-mode capacitor C7; a first end of the first common-mode capacitor C4 is connected to the output end of one of the first coils, a second end of the first common-mode capacitor C4 is connected to the first end of the second common-mode capacitor C5, a second end of the second common-mode capacitor C5 is connected to the output end of another of the first coils, and a connection point between the first common-mode capacitor C4 and the second common-mode capacitor C5 is grounded; a first end of the third common-mode capacitor C6 is connected to the output end of one of the second coils, a second end of the third common-mode capacitor C6 is connected to the first end of the fourth common-mode capacitor C7, a second end of the fourth common-mode capacitor C7 is connected to the output end of another of the second coils, and a connection point between the third common-mode capacitor C6 and the fourth common-mode capacitor C7 is grounded.

[0053] A bidirectional filtering circuit can be formed by the first common-mode inductor L1 and the second common-mode inductor L2 arranged in series, which can be installed at the front end of the power module to play a bidirectional filtering role on the power module, filtering out the electromagnetic interference transmitted from the power grid to the system and the electromagnetic interference sent from the system to the power grid. The first differential mode capacitor C1 and the second differential mode capacitor C2 arranged at the input and output ends of the first coil in the first common-mode inductor L1, and the third differential mode capacitor C3 arranged at the output end of the second common-mode inductor L2 can suppress differential mode interference multiple times and effectively reduce high-frequency noise. Among them, the number of the first differential mode capacitor C1, the second differential mode capacitor C2 and the third differential mode capacitor C3 can be set to two or more in parallel. The first common-mode capacitor C4 and the second common-mode capacitor C5, which are arranged in series between the two first coils, and the third common-mode capacitor C6 and the fourth common-mode capacitor C7, which are arranged in series between the two second coils, can suppress common-mode interference multiple times, and the connection point of the first common-mode capacitor C4 and the second common-mode capacitor C5 and the connection point of the third common-mode capacitor C6 and the fourth common-mode capacitor C7 are grounded, thereby improving the stability and reliability of the filter circuit while reducing noise.

[0054] The filtering circuit composed of the first common-mode inductor L1, the second common-mode inductor L2, the first differential-mode capacitor C1, the second differential-mode capacitor C2, the third differential-mode capacitor C3, the first common-mode capacitor C4, the second common-mode capacitor C5, the third common-mode capacitor C6 and the fourth common-mode capacitor C7 can achieve a common-differential mode suppression of 50dB in the frequency band of 150kHz to 5MHz, and can effectively suppress the conducted interference of the transmission line of the electronic system, so that the power supply filter provided in the embodiment of the present application has a high noise suppression capability while meeting the requirements of ultra-thin structure and high power.

[0055] like Figure 4As shown, in some embodiments, there are two mounting holes 211, the two mounting holes 211 include a first mounting hole 211a and a second mounting hole 211b, the first mounting hole 211a and the second mounting hole 211b are arranged at intervals on the circuit board 210, the first common-mode inductor L1 is installed in the first mounting hole 211a, and the second common-mode inductor L2 is installed in the second mounting hole 211b. By installing the first common-mode inductor L1 and the second common-mode inductor L2 in the first mounting hole 211a and the second mounting hole 211b arranged at intervals, respectively, the distance between the first common-mode inductor L1 and the second common-mode inductor L2 can be determined, so as to avoid the first common-mode inductor L1 and the second common-mode inductor L2 from interfering with each other due to being too close, and at the same time, the smooth transmission of the signal can be ensured.

[0056] In some embodiments, the first differential mode capacitor C1 and the second differential mode capacitor C2 are disposed around the first mounting hole 211a; the third differential mode capacitor C3, the first common mode capacitor C4, the second common mode capacitor C5, the third common mode capacitor C6 and the fourth common mode capacitor C7 are disposed around the second mounting hole 211b. According to the relative positions of the differential mode capacitors 230 and the common mode capacitors 240 in the filter circuit, the capacitors are distributed around the first common mode inductor L1 and the second common mode inductor L2, so that the capacitors can work together effectively and there are gaps between adjacent capacitors to avoid unnecessary capacitive coupling and achieve the best filtering effect.

[0057] In some embodiments, it also includes a positive input terminal 111, a negative input terminal 112, a positive output terminal 113, and a negative output terminal 114 disposed on the housing 100. The positive output terminal 113 is connected to the input end of one of the first coils, and the negative input terminal 112 is connected to the input end of the other first coil; the positive output terminal 113 is connected to the output end of one of the second coils, and the negative output terminal 114 is connected to the output end of the other second coil. Specifically, the positive input terminal 111, the negative input terminal 112, the positive output terminal 113, and the negative output terminal 114 can be made of an iron-nickel alloy and plated with a nickel layer on the outer surface, so that each terminal has good conductivity and is convenient for welding each terminal in an electronic device.

[0058] Among them, the positive input terminal 111, the negative input terminal 112, the positive output terminal 113 and the negative output terminal 114 can all be connected to the side of the shell 110 facing away from the cover plate 120, the positive input terminal 111 and the negative input terminal 112 can be arranged at one end of the extension direction of the shell 100, and the positive output terminal 113 and the negative output terminal 114 can be arranged at the other end of the extension direction of the shell 100. The shell 110 can be provided with through holes corresponding to each terminal, and each terminal extends into the accommodating cavity 101 through the through holes to connect and conduct with the circuit board 210. Among them, an insulating layer should be provided between each terminal and the shell 110 to prevent the shell 110 from conducting between the terminals and forming a short circuit.

[0059] At both ends of the extension direction of the circuit board 210, a positive input contact 212, a negative input contact 213, a positive output contact 214, and a negative output contact 215 can be respectively provided. In the first common mode capacitor C4, the input end of one of the first coils can be used as the positive input end, and the input end of the other first coil can be used as the negative input end, and are respectively connected to the positive input contact 212 and the negative input contact 213 through the circuit pattern on the circuit board 210. In the second common mode capacitor C5, the output end of the second coil connected in series with the first coil at the positive input end can be used as the positive output end, and the output end of the other second coil can be used as the negative output end, and are respectively connected to the positive output contact 214 and the negative output contact 215 through the circuit pattern on the circuit board 210.

[0060] After the positive input terminal 111, the negative input terminal 112, the positive output terminal 113 and the negative output terminal 114 are extended into the accommodating cavity 101, they are respectively connected to the corresponding positive input contact 212, the negative input contact 213, the positive output contact 214 and the negative output contact 215, and each terminal is connected to the filter circuit, so that the power filter can be connected to the electronic device using each terminal to realize the transmission of electrical signals between the power filter and other components in the electronic device.

[0061] In some embodiments, a grounding terminal is also included in the housing 100; the grounding terminal is connected to the connection point of the first common-mode capacitor C4 and the second common-mode capacitor C5 and / or the connection point of the third common-mode capacitor C6 and the fourth common-mode capacitor C7. Specifically, the grounding terminal can also be made of an iron-nickel alloy and plated with a nickel layer on the outer surface, so that each terminal has good conductivity and is convenient for welding the grounding terminal in the electronic device. The grounding terminal can also be configured at one end of the extension direction of the housing 100, for example, it is arranged between the positive output terminal 113 and the negative output terminal 114, and the grounding terminal passes through the housing 110 and extends into the accommodating cavity 101 to connect with the circuit board 210. Among them, the grounding terminal can be directly connected to the housing 110 so as to provide leakage protection for the housing 100.

[0062] A grounding contact 216 may be provided on the circuit board 210. The connection point between the first common mode capacitor C4 and the second common mode capacitor C5, and the connection point between the third common mode capacitor C6 and the fourth common mode capacitor C7 are all connected to the grounding contact 216 through the circuit pattern on the circuit board 210. The grounding terminal is connected to the grounding contact 216 on the circuit board 210, so that the first common mode capacitor C4 and the second common mode capacitor C5, and the third common mode capacitor C6 and the fourth common mode capacitor C7 are grounded by using a grounding terminal to ensure safety. In addition, two grounding contacts 216 may be provided on the circuit board 210, and two grounding terminals are provided on the housing 100 to be connected to the connection point between the first common mode capacitor C4 and the second common mode capacitor C5, and the connection point between the third common mode capacitor C6 and the fourth common mode capacitor C7, respectively.

[0063] like Figure 2 As shown, in some embodiments, potting glue 300 is further included, which is filled in the accommodating cavity 101 and is used to encapsulate the filter component 200 in the accommodating cavity 101. The potting glue 300 can be epoxy resin potting glue 300, silicone resin potting glue 300 or polyurethane potting glue 300. During assembly, after the filter component 200 is installed in the housing 110, canned glue can be injected into the housing 110 through the opening of the housing 110, so that the canned glue is filled in the accommodating cavity 101, so as to prevent the filter component 200 from detaching from the housing 100 after being impacted or vibrated, thereby improving the vibration resistance, impact resistance and reliability of the power filter, and effectively ensuring the normal operation of the power filter.

[0064] On the other hand, the embodiment of the present application also provides a preparation process for preparing the power supply filter provided in the embodiment of the first aspect above, combined with Figure 6 and Figure 7 As shown, the preparation process includes the following steps:

[0065] Step 1: Open a mounting hole 211 on the circuit board 210, and set a detachable support assembly 400 in the mounting hole 211;

[0066] Step 2: Place the common mode inductor 220 into the mounting hole 211 and place it on the support assembly 400;

[0067] Step 3, soldering the common mode inductor 220 on the circuit board 210 and removing the supporting assembly 400;

[0068] Step 4: soldering the differential mode capacitor 230 and the common mode capacitor 240 on the circuit board 210, so that the circuit board 210, the common mode inductor 220, the differential mode capacitor 230 and the common mode capacitor 240 form a filter assembly 200;

[0069] Step five: install the filter assembly 200 in the accommodating cavity 101 of the housing 100 .

[0070] Among them, the support component 400 enables a support positioning structure that can be detachably connected to the mounting hole 211 of the circuit board 210. Before installing the common-mode inductor 220, the support component 400 is first connected to the circuit board 210 so that part of the support component 400 is located below the mounting hole 211. After the common-mode inductor 220 is placed in the mounting hole 211, the common-mode inductor 220 can fall on the support component 400, so that the support component 400 can be used to locate the position of the common-mode inductor 220 in the mounting hole 211, and the common-mode inductor 220 can maintain a stable position during the welding process with the circuit board 210 and will not fall from the mounting hole 211, thereby reducing the assembly difficulty of the filter component 200 and improving the production quality of the entire power filter.

[0071] like Figure 7 As shown, in some embodiments, the support assembly 400 may include a base 410, a fixed splint 420, a movable splint 430, and a screw rod 440. The fixed splint 420 and the movable splint 430 are both disposed above the base 410 and are respectively located on opposite sides of the base 410. The fixed splint 420 and the movable splint 430 are both arc-shaped plates, and the size of the arc-shaped plates is adapted to the inner diameter of the mounting hole 211, so that the outer side surfaces of the fixed splint 420 and the movable splint 430 can abut against the inner wall of the mounting hole 211. A slide groove 412 is disposed on the base 410, and a guide block 431 is disposed at the bottom of the movable splint 430, and the guide block 431 is slidably embedded in the slide groove 412, so that the movable splint 430 can slide toward or away from the fixed splint 420. The base 410 is hollow so that the interior of the base 410 has a cavity 411, and the screw rod 440 is rotatably set in the cavity 411, and the axial direction of the screw rod 440 is the same as the extension direction of the slide groove 412. A slider 441 is threadedly connected to the screw rod 440, and the slider 441 is fixedly connected to the guide block 431, so that the movable splint 430 can be driven to slide by the rotation of the screw rod 440.

[0072] Furthermore, a positioning portion 421 may be provided on the side of the fixed clamp 420 facing away from the movable clamp 430. The positioning portion 421 can abut against the lower surface of the circuit board 210 after the fixed clamp 420 is inserted into the mounting hole 211, so as to position the top of the fixed clamp 420 and the movable clamp 430 flush with the upper surface of the circuit board 210, thereby preventing the top of the fixed clamp 420 and the movable clamp 430 from exceeding the upper surface of the circuit board 210 and affecting the welding of the coil in the common-mode inductor 220 and the circuit board 210.

[0073] When in use, the distance between the fixed clamp plate 420 and the movable clamp plate 430 is small, so that the fixed clamp plate 420 and the sliding clamp plate can be embedded in the mounting hole 211 from bottom to top, and then the movable clamp plate 430 is driven to move in the direction away from the fixed clamp plate 420 by rotating the screw rod 440, so that the fixed clamp plate 420 and the movable clamp plate 430 are respectively pressed against the inner wall of the mounting hole 211, and the support assembly 400 is connected to the circuit board 210 by friction. At this time, a positioning cavity for placing the common-mode inductor 220 is formed between the fixed clamp plate 420 and the movable clamp plate 430. After the common-mode inductor 220 is placed in the positioning cavity, the common-mode inductor 220 falls on the upper surface of the base 410 to support the common-mode inductor 220 in the mounting hole 211 of the circuit board 210 and position the common-mode inductor 220 in the center of the mounting hole 211 to avoid the coil of the common-mode inductor 220 from contacting and affecting the inner wall of the surrounding side of the mounting hole 211.

[0074] After the coil of the common-mode inductor 220 is welded to the circuit board 210, the common-mode inductor 220 can be maintained in the mounting hole 211 with the support of the coil. At this time, the screw rod 440 can be rotated in the opposite direction to move the movable clamping plate 430 toward the fixed clamping plate 420, and the contact force on the inner wall of the mounting hole 211 can be relaxed, and the support component 400 can be removed from the mounting hole 211 to complete the welding of the common-mode inductor 220 and the circuit board 210. In addition, after removing the support component 400, an adhesive can be set between the common-mode inductor 220 and the circuit board 210 to further reinforce the position of the common-mode inductor 220 and ensure that the position of the common-mode inductor 220 in the mounting hole 211 is stable.

[0075] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A power supply filter, characterized in that: It includes a shell and a filter component, the shell has a containing cavity, and the filter component is arranged in the containing cavity; the filter component includes a circuit board, a common-mode inductor, a differential-mode capacitor and a common-mode capacitor, the common-mode inductor, the differential-mode capacitor and the common-mode capacitor are all electrically connected to the circuit board, the circuit board is provided with a mounting hole, and the common-mode inductor is located in the mounting hole.

2. The power supply filter according to claim 1, characterized in that: There are two common-mode inductors, the two common-mode inductors include a first common-mode inductor and a second common-mode inductor, the first common-mode inductor includes a first magnetic core and two first coils wound on the first magnetic core; the second common-mode inductor includes a second magnetic core and two second coils wound on the second magnetic core; the two first coils correspond to the two second coils one by one, and the output end of the first coil is connected to the input end of the corresponding second coil; The differential mode capacitors are provided with three, and the three differential mode capacitors include: a first differential mode capacitor, a second differential mode capacitor and a third differential mode capacitor; one end of the first differential mode capacitor is connected to the input end of one of the first coils, and the other end is connected to the input end of another of the first coils; one end of the second differential mode capacitor is connected to the output end of one of the first coils, and the other end is connected to the output end of another of the first coils; one end of the third differential mode capacitor is connected to the output end of one of the second coils, and the other end is connected to the output end of another of the second coils; There are four common-mode capacitors, and the four common-mode capacitors include: a first common-mode capacitor, a second common-mode capacitor, a third common-mode capacitor and a fourth common-mode capacitor; a first end of the first common-mode capacitor is connected to an output end of one of the first coils, a second end of the first common-mode capacitor is connected to a first end of the second common-mode capacitor, a second end of the second common-mode capacitor is connected to an output end of another of the first coils, and a connection point between the first common-mode capacitor and the second common-mode capacitor is grounded; a first end of the third common-mode capacitor is connected to an output end of one of the second coils, a second end of the third common-mode capacitor is connected to a first end of the fourth common-mode capacitor, a second end of the fourth common-mode capacitor is connected to an output end of another of the second coils, and a connection point between the third common-mode capacitor and the fourth common-mode capacitor is grounded.

3. The power supply filter according to claim 2, characterized in that: There are two mounting holes, the two mounting holes include a first mounting hole and a second mounting hole, the first mounting hole and the second mounting hole are arranged at intervals on the circuit board, the first common-mode inductor is installed in the first mounting hole, and the second common-mode inductor is installed in the second mounting hole.

4. The power supply filter according to claim 3, characterized in that: The first differential mode capacitor and the second differential mode capacitor are arranged around the first mounting hole; the third differential mode capacitor, the first common mode capacitor, the second common mode capacitor, the third common mode capacitor and the fourth common mode capacitor are arranged together around the second mounting hole.

5. The power supply filter according to claim 2, characterized in that: It also includes a positive input terminal, a positive output terminal, a negative input terminal and a negative output terminal arranged on the shell, the positive output terminal is connected to the input end of one of the first coils, and the positive output terminal is connected to the input end of the other first coil; the negative input terminal is connected to the output end of one of the second coils, and the negative output terminal is connected to the output end of the other second coil.

6. The power supply filter according to claim 2, characterized in that: It also includes a grounding terminal arranged on the housing; the grounding terminal is connected to a connection point between the first common-mode capacitor and the second common-mode capacitor and / or a connection point between the third common-mode capacitor and the fourth common-mode capacitor.

7. The power supply filter according to any one of claims 1 to 6, characterized in that: The housing comprises a shell and a cover plate, the shell has an opening, the cover plate is connected to the opening of the shell and covers the opening, and the accommodating cavity is formed between the shell and the cover plate.

8. The power supply filter according to claim 7, characterized in that: The housing further comprises at least one fixing plate, and the fixing plate is arranged on a side of the shell or the cover plate facing away from the accommodating cavity.

9. The power supply filter according to any one of claims 1 to 6, characterized in that: It also includes potting glue, which is filled in the accommodating cavity and is used to encapsulate the filter component in the accommodating cavity.

10. A process for preparing a power supply filter according to any one of claims 1 to 8, characterized in that: include: A mounting hole is opened on the circuit board, and a detachable supporting component is arranged in the mounting hole; Put the common mode inductor into the mounting hole and place it on the supporting assembly; Soldering the common-mode inductor on the circuit board and removing the supporting assembly; Soldering the differential mode capacitor and the common mode capacitor on the circuit board, so that the circuit board, the common mode inductor, the differential mode capacitor and the common mode capacitor constitute the filter component; The filter assembly is installed in the accommodating cavity of the housing.

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