PCB (printed circuit board), PCB circuit board and ultrathin filter made of PCB circuit board

Abstract

The ultra-thin filter comprises a circuit board, an inductor, a capacitor and an active filter circuit, the circuit board is at least hollowed five areas, terminal hole positions are reserved on the peripheries of the areas, and the hollowed areas at least account for more than 30% of the area of the board; the number of the inductors is at least four, the inductors are arranged in the four hollowed-out areas respectively, and the terminals are welded to the positions of reserved terminal holes in the peripheries of the areas. The at least two capacitors are arranged in the remaining hollow area, and the terminals are welded at the positions of the reserved terminal holes on the periphery of the area. According to the ultra-thin filter, the inductor and the capacitor which are large in size in the filter are embedded into the circuit board, most of the other components are packaged through surface mount devices, the ultra-thin filter design is achieved, and the excellent filtering performance is achieved; the product is attractive in structure, uniform in device distribution, good in heat dissipation effect, simple in manufacturing process and good in product performance consistency.

Description

Technical Field

[0001] The invention belongs to the field of filters, and in particular relates to a PCB board, a PCB circuit board and an ultra-thin filter made therefrom. Background Art

[0002] With the continuous development of electronic circuit technology, the power density of switching power supplies is constantly improving. High efficiency, high reliability, high frequency design and low cost have become the development direction of switching power supplies. The filtering circuit of the switching power supply itself is limited. Accordingly, the demand for switching power supplies that can make the switching power supply meet higher electromagnetic compatibility performance and thinner electromagnetic compatibility filters is also increasing.

[0003] Traditional filters are easy to design and manufacture. They place inductors and capacitors on top of the circuit board and then assemble them with the base of the housing. The height has become a big disadvantage. As the power density of switching power supplies continues to increase, the disadvantages of traditional filters are becoming more and more obvious. When the performance requirements are high, because the better the performance of the filter, the greater the current, the larger the inductor and capacitor device structure inside, the overall height of the filter will also be very high, and the filter volume will be very large, which cannot be used with ultra-thin brick-type power supplies. In addition, there are devices close to the inductor, and the heat dissipation is very poor. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides an ultra-thin filter suitable for matching switching power supply products with limited height and high electromagnetic compatibility level to meet market demand.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] An ultra-thin filter comprises a circuit board, an inductor, a capacitor and components of an active filter circuit. The PCB board is provided with more than four hollowed-out areas, and terminal holes are provided around the hollowed-out areas. Pin terminals of the inductor and the capacitor are fixedly installed at the positions of the terminal holes so that the inductor and the capacitor are suspended flat in the hollowed-out area of ​​the PCB board. There are more than three inductors, each occupying one hollowed-out area of ​​the PCB board. The components of the active filter circuit are arranged in the non-hollowed-out area of ​​the PCB board.

[0007] Preferably, the total area of ​​the plurality of hollowed-out regions provided on the circuit board accounts for more than 30% of the board area.

[0008] Preferably, the shapes of the hollowed-out area of ​​the circuit board include circular, rectangular and "convex" shapes.

[0009] Preferably, the inductor comprises two shapes, one is a common mode inductor made of a toroidal magnetic core, and the other is a differential mode inductor made of a square combined magnetic core, and both inductor bodies are assembled and suspended flat in the hollowed-out area of ​​the circuit board.

[0010] Preferably, the capacitors are metal film capacitors, and there are two or more of them, and the capacitor bodies lie flat in pairs with their sides close together, and are assembled and placed in a hollowed-out area.

[0011] Preferably, the PCB board is a double-sided board, the PCB board is rectangular, and has notches at four corners with the same shape.

[0012] Preferably, when the ultra-thin filter is not installed with a housing, the overall height is equal to the highest height of the inductor.

[0013] The present invention also provides a PCB board suitable for an ultra-thin filter. The PCB board is rectangular and has more than four hollowed-out areas. The shapes of the hollowed-out areas include circular, rectangular and "convex" shapes.

[0014] Preferably, the four corners of the PCB board are provided with notches, and the notches have the same shape.

[0015] The present invention also provides a PCB circuit board, which is suitable for an ultra-thin filter, comprising a PCB board and common-mode inductors, differential-mode inductors, capacitors and components of an active filter circuit assembled thereon, wherein more than four hollowed-out areas are provided on the PCB board, and the total area of ​​the hollowed-out areas accounts for more than 30% of the board area, terminal holes are provided around the hollowed-out areas, and the pin terminals of the common-mode inductors, differential-mode inductors and capacitors are fixedly installed at the positions of the terminal holes, so that the common-mode inductors, differential-mode inductors and capacitors are suspended flat in the hollowed-out areas of the circuit board; the components of the active filter circuit are arranged in non-hollowed-out areas on the circuit board; and the overall height of the PCB circuit board is not higher than the height of the highest inductor.

[0016] The present invention further provides an ultra-thin filter, which is suitable for an ultra-thin filter, comprising a PCB board and an inductor, a capacitor and components of an active filter circuit assembled thereon, wherein the PCB board is provided with five hollowed-out areas, and terminal holes are provided around the hollowed-out areas, and the inductor and the capacitor are fixedly mounted on the PCB board through the terminal holes; there are four inductors, which are respectively placed in the four hollowed-out areas; there are two capacitors, and the capacitor bodies are laid flat in pairs with their sides close together, and are assembled and placed in one hollowed-out area; and the components of the active filter circuit are arranged in the non-hollowed-out area of ​​the PCB board.

[0017] The beneficial effects of the ultra-thin filter of the present invention are:

[0018] 1. The largest inductors and capacitors in the filter are suspended flat in the hollowed-out area of ​​the circuit board, so that the main bodies of the inductors and capacitors are embedded in and penetrate the circuit board, so that when the filter is not installed with a casing, the overall height is not higher than the height of the highest inductor; and the windings on both sides of the inductor are exposed and are not close to nearby components, so the heat dissipation effect is good.

[0019] 2. In the traditional filter, the inductor and capacitor are soldered on the board, and the floating height of the device needs to be considered, but this does not need to be considered in the present invention.

[0020] 3. The inductor and capacitor are placed flat, which greatly reduces the overall height of the product.

[0021] 4. Devices are placed on both sides of the circuit board, and active filtering circuits can be placed without affecting the overall height. The combination of active + passive filtering solutions can greatly improve the filtering performance.

[0022] 5. The power devices are dispersed in the circuit board, with a large heat dissipation area and good heat dissipation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A three-dimensional structural diagram of the ultra-thin filter of the present invention from a front perspective;

[0024] Figure 2 A three-dimensional structural diagram of the ultra-thin filter of the present invention from a back perspective;

[0025] Figure 3 It is a three-dimensional exploded diagram of the ultra-thin filter of the present invention;

[0026] Figure 4 It is a three-dimensional structural diagram of the PCB board of the ultra-thin filter of the present invention, mainly marking the hollowed-out area;

[0027] Figure 5 It is a three-dimensional structural diagram of the PCB board of the ultra-thin filter of the present invention, mainly identifying the terminal holes.

[0028] The reference numerals in the above drawings are as follows:

[0029] 1. PCB board, 11. Notch, 2. Hollow area, 21. 22. 23 Circular hollow area, 24. Rectangular hollow area, 25. "convex" hollow area, 211. 221. 231. 241. 251. Terminal hole, 3. 4. 5. Common mode inductor, 6. Differential mode inductor, 7. 8. Capacitor, 9. Components DETAILED DESCRIPTION

[0030] In order to make the technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and implementation methods. However, the specific embodiments described herein are only used to explain the present invention and are not intended to limit the invention.

[0031] like Figures 1 to 3As shown, an ultra-thin filter provided by the present invention comprises a PCB board 1, a hollowed-out area 2, a first common-mode inductor 3, a second common-mode inductor 4, a third common-mode inductor 5, a differential-mode inductor 6, a first metal film capacitor 7, a second metal film capacitor 8 and components 9 of an active filter circuit. The common-mode inductor is made of a ring-shaped magnetic core, and the differential-mode inductor is made of a square combined magnetic core. More than four hollowed-out areas are provided on the PCB board. In this embodiment, five hollowed-out areas are provided on the PCB board 1, and the total area of ​​the hollowed-out areas accounts for more than 30% of the board area. Terminal holes are provided around the hollowed-out areas, and the pin terminals of the common-mode inductors 3, 4, 5, the differential-mode inductors 6, and the capacitors 7, 8 are fixedly installed at the positions of the terminal holes, so that the common-mode inductors 3, 4, 5, the differential-mode inductors 6, and the capacitors 7, 8 are suspended flat in the hollowed-out area 2 of the PCB board 1; the components 9 of the active filter circuit are composed of components such as amplifiers, resistors, and chip capacitors, most of which adopt a chip packaging structure and are arranged in the non-hollowed-out area of ​​the PCB board 1, including the upper surface and the lower surface of the PCB board, without affecting the overall height of the filter product. Since the largest inductors and capacitors in the filter are suspended flat in the hollowed-out area of ​​the circuit board, the main bodies of the inductors and capacitors can be embedded in and penetrate the circuit board, so that the overall height of the PCB circuit board assembled with these electronic components is not higher than the height of the highest inductor, that is, the overall height of the PCB circuit board without the filter housing can be equal to the height of the highest inductor. In this way, an ultra-thin filter design is achieved while having excellent filtering performance; the product has a beautiful structure, uniform device distribution, good heat dissipation effect, simple manufacturing process, and good product performance consistency.

[0032] like Figures 4 to 5 As shown, it is a three-dimensional structure diagram of the PCB board of the ultra-thin filter of the present invention. There are 5 hollowed-out areas of the PCB board 1, corresponding to circular hollowed-out areas 21, 22, 23, corresponding to rectangular hollowed-out area 24, and corresponding to "convex" hollowed-out area 25. Terminal holes 211, 221, 231, 241, 251 are reserved around the hollowed-out areas. The size and position of the terminal holes are determined according to the terminal pins of the device and the needs of fixed installation. The preferred PCB board 1 adopts a double-sided board, the PCB board is rectangular, and there are notches 11 at the four corners, and the shape of the notches 11 is consistent.

[0033] The first common-mode inductor 3, the second common-mode inductor 4, and the third common-mode inductor 5 are respectively placed in the hollowed-out areas 21, 22, and 23, and their pins are welded in the reserved terminal holes 211, 221, and 231; the differential-mode inductor 6 is placed in the hollowed-out area 25, and its pins are welded in the reserved terminal hole 251; the first metal film capacitor 7 and the second metal film capacitor 8 are placed flat and close to each other on the sides in the hollowed-out area 24, and their pins are welded in the reserved terminal hole 241; the components 9 of the active filter circuit are arranged in the non-hollowed-out areas on both sides of the PCB board 1.

[0034] The main heat-generating components, the first common-mode inductor 3, the second common-mode inductor 4, the third common-mode inductor 5, and the differential-mode inductor 6, are placed flat in the hollowed-out areas 21, 22, 23, and 25, which not only disperses them in the PCB board without being close to nearby components, but also allows the upper and lower main heat-generating surfaces of the heat-generating components to be exposed for heat dissipation, which not only greatly reduces the overall height of the filter, but is also beneficial to the heat dissipation of the main heat-generating components such as the inductor, making it easier to meet high-current usage scenarios.

[0035] The above embodiments are only used to help understand the methods and core ideas of the present invention. For ordinary technicians in this technical field, without departing from the principles of the present invention, other equivalent application schemes that can be naturally associated with the above description and examples, as well as several improvements and modifications to the present invention, all fall within the scope of protection of the claims of the present invention.

Claims

1. An ultra-thin filter, comprising a PCB board, an inductor, a capacitor and components of an active filter circuit, characterized in that: The PCB board is provided with more than four hollowed-out areas, and terminal holes are provided around the hollowed-out areas. The pin terminals of the inductor and the capacitor are fixedly installed at the positions of the terminal holes so that the inductor and the capacitor are suspended flat in the hollowed-out areas of the PCB board. There are more than three inductors, each occupying one hollowed-out area of ​​the PCB board; The components of the active filter circuit are arranged in the non-hollowed-out area of ​​the PCB board.

2. The ultrathin filter according to claim 1, characterized in that: The total area of ​​the several hollowed-out regions formed on the PCB board accounts for more than 30% of the board area.

3. The ultrathin filter according to claim 1, characterized in that: The shapes of the hollowed-out area of ​​the PCB board include circular, rectangular and "convex" shapes.

4. The ultra-thin filter according to claim 1, characterized in that: The inductor includes two shapes, one is a common mode inductor made of a ring-shaped magnetic core, and the other is a differential mode inductor made of a square combined magnetic core. Both inductor bodies are assembled and suspended flat in the hollowed-out area of ​​the PCB board.

5. The ultra-thin filter according to claim 1, characterized in that: The capacitors are metal film capacitors, and there are more than two of them. The capacitor bodies lie flat in pairs with their sides close together and are assembled and placed in a hollowed-out area.

6. The ultrathin filter according to claim 1, characterized in that: The PCB board adopts a double-sided cloth board, the PCB board is rectangular, and there are notches at four corners, and the notches have the same shape.

7. The ultrathin filter according to claim 1, characterized in that: When the ultra-thin filter is not installed with a housing, the overall height is equal to the highest height of the inductor.

8. A PCB board suitable for an ultra-thin filter, characterized in that: The PCB board is rectangular and has more than 4 hollowed-out areas, and the total area of ​​the hollowed-out areas accounts for more than 30% of the board area. The shapes of the hollowed-out areas include circular, rectangular and "convex" shapes.

9. The PCB board according to claim 8, characterized in that: The four corners of the PCB board are all provided with notches, and the notches have the same shape.

10. A PCB circuit board, suitable for an ultra-thin filter, comprising a PCB board and common-mode inductors, differential-mode inductors, capacitors and components of an active filter circuit assembled thereon, characterized in that: The PCB board is provided with more than 4 hollowed-out areas, and the total area of ​​the hollowed-out areas accounts for more than 30% of the board area. Terminal holes are provided around the hollowed-out areas, and the pin terminals of the common-mode inductor, the differential-mode inductor and the capacitor are fixedly installed at the positions of the terminal holes, so that the common-mode inductor, the differential-mode inductor and the capacitor are suspended flat in the hollowed-out area of ​​the PCB board; The components of the active filter circuit are arranged in the non-hollowed-out area of ​​the PCB board; The overall height of the PCB circuit board is equal to the height of the tallest inductor or capacitor.

11. An ultra-thin filter, comprising a PCB board and components of an inductor, a capacitor and an active filter circuit assembled thereon, characterized in that: The PCB board is provided with five hollowed-out areas, and terminal holes are provided around the hollowed-out areas. The inductor and the capacitor are fixedly mounted on the PCB board through the terminal holes. There are four inductors, which are respectively placed in four hollowed-out areas; There are two capacitors, and the capacitor bodies are laid flat in pairs with their sides close together, and are assembled and placed in a hollowed-out area.

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