A multi-layer structure filter and a vehicle-mounted power DCDC conversion device

Abstract

The application provides a multilayer structure filter and a vehicle-mounted power DCDC conversion device, wherein the multilayer structure filter comprises N layers of PCBs which are sequentially and spaced apart from top to bottom, and N is greater than or equal to 3; N-1 levels of output inductors which are sequentially and spaced apart from top to bottom, and each output inductor is connected to the adjacent upper and lower layers of PCBs through the input end and the output end; N-1 levels of output capacitors which are sequentially and spaced apart from top to bottom, and each output capacitor is connected to the second layer to the Nth layer of PCBs; and a filter output terminal which is connected to the output end of the N-1th level of output inductor. The multilayer structure filter and the vehicle-mounted power DCDC conversion device using the same are used for the output filter of the DCDC converter of the vehicle-mounted power conversion product, and a multilayer structure filter is provided, so that the filter is miniaturized to save the installation space, and the heat dissipation, filtering and shielding functions of the large-current path of the output end of the DCDC converter are better realized.

Description

Technical Field

[0001] This invention relates to the field of DC-DC converter technology, and in particular to a multilayer filter and a vehicle power supply DC-DC conversion device using the same. Background Technology

[0002] With the development of new energy vehicle technology, the number of in-vehicle intelligent devices is gradually increasing, leading to a continuous rise in the output power demand for DC-DC converters in vehicle power supply products. Simultaneously, the demand for miniaturization of these converters is also increasing to save installation space, allowing for more room in the vehicle to accommodate these newly added intelligent devices and improve the intelligence, integration, and comfort levels of new energy vehicles. However, the increased output power of DC-DC converters in vehicle power supply products also results in a greater output current, posing a greater challenge to the design of high-current filters at the output end.

[0003] Therefore, providing a miniaturized, high-current filter suitable for the output of a DC-DC converter in automotive power products is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] In order to solve the technical problem of the lack of a miniaturized, high-current filter suitable for the output of a DC-DC converter in automotive power supply products, this invention proposes a multilayer filter and an automotive power supply DC-DC converter device using the same.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0006] This invention proposes a multilayer filter, comprising:

[0007] N layers of PCB are arranged sequentially from top to bottom at intervals, where N is greater than or equal to 3;

[0008] N-1 stages of output inductors are arranged at intervals from top to bottom. Each stage of output inductor is connected to the adjacent upper and lower PCB layers through its input and output terminals respectively.

[0009] N-1 stages of output capacitors are arranged at intervals from top to bottom, with each stage of output capacitor connected to the second to Nth layers of the PCB respectively;

[0010] The filter output terminal is connected to the output terminal of the (N-1)th stage output inductor.

[0011] Preferably, when N equals 3, the input and output terminals of the first-stage output inductor are connected to the first and second PCB layers respectively, the input and output terminals of the second-stage output inductor are connected to the second and third PCB layers respectively, the first-stage output capacitor and the second-stage output capacitor are connected to the second and third PCB layers respectively, and the filter output terminal is connected to the output terminal of the second-stage output inductor.

[0012] Preferably, the first-stage output inductor includes: a first magnetic core and at least two windings disposed in the first magnetic core and connected in parallel with each other. The top mounting surface of the first magnetic core is provided with a first input pin and an output pin. The end of the first input pin away from the first magnetic core is higher than the end of the output pin away from the first magnetic core. The first input pin and the output pin are respectively connected to the first layer PCB and the second layer PCB. The top mounting surface of the first magnetic core abuts against the bottom surface of the second layer PCB.

[0013] The first-stage output capacitor includes: at least one first housing mounted on the bottom surface of the second-layer PCB and a capacitor component disposed within the first housing;

[0014] The second-stage output inductor includes: a second magnetic core and a winding disposed within the second magnetic core. The top surface of the second magnetic core is provided with a second input pin, and the bottom surface of the second magnetic core is provided with an output copper busbar. The second input pin and the output copper busbar are respectively connected to the second layer PCB and the third layer PCB.

[0015] The second-stage output capacitor includes: a second housing mounted on the bottom surface of the third-layer PCB and a capacitor component inside the second housing;

[0016] The filter output terminal is connected to the output copper busbar.

[0017] Preferably, when N equals 4, the input and output terminals of the third-stage output inductor are connected to the second and third PCB layers respectively, the input and output terminals of the fourth-stage output inductor are connected to the third and second PCB layers respectively, the fourth-stage output capacitor is connected to the fourth PCB layer, and the filter output terminal is connected to the output terminal of the third-stage output inductor.

[0018] Preferably, the winding of the first-stage output inductor is formed by winding multiple turns of copper busbar, and the winding of the second-stage output inductor is formed by winding a single-turn copper busbar.

[0019] Preferably, one end of the output copper busbar is vertically connected to the bottom surface of the second magnetic core, and the other end of the output copper busbar passes through the third PCB and is attached to the bottom surface of the third PCB. The first input pin passes through the second PCB and is soldered to the first PCB. The output pin and the second input pin are soldered to the second PCB.

[0020] Preferably, the filter output terminal includes:

[0021] The mounting base has an output port at one end and a connecting copper busbar at the other end. The end of the connecting copper busbar away from the mounting base has a mounting screw hole, and the other end of the output copper busbar has a connecting screw hole that matches the mounting screw hole. The filter output terminal is connected to the output copper busbar by passing a fixing screw through the mounting screw hole and the connecting screw hole.

[0022] The present invention also provides an on-board power supply DC-DC converter, including a housing, and a multi-layer filter as described in any one of claims 1-7 mounted on the housing, and a power switch, a transformer and a secondary switch connected to the first layer PCB.

[0023] Furthermore, a cavity is formed between the first-stage output inductor and the second-stage output inductor in the housing to separate the shielding inductor.

[0024] Furthermore, thermally conductive material is filled between the first-stage output inductor, the second-stage output inductor, and the housing.

[0025] Compared with existing technologies, the multi-layer filter and the on-board power supply DC-DC converter device using the present invention provide a multi-layer filter design scheme for the output filter of the DC-DC converter in the power conversion product of the on-board power supply. While realizing the miniaturization of the filter and saving installation space, it can better achieve the heat dissipation, filtering and shielding performance of the high current path at the output of the DC-DC converter. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the circuit topology of an embodiment of the multilayer filter of the present invention;

[0028] Figure 2 This is a schematic diagram of the inductor device in an embodiment of the multilayer filter of the present invention;

[0029] Figure 3 This is a schematic diagram of the overall structure of an embodiment of the multilayer filter of the present invention;

[0030] Figure 4 This is a schematic diagram of an on-board power supply DC-DC converter according to an embodiment of the multilayer structure filter of the present invention.

[0031] The main markings in the attached figures are as follows:

[0032] 1. First-stage output inductor; 11. First magnetic core; 12. First input pin; 13. Output pin; 14. Magnetic core holder; 2. First-layer PCB; 3. Second-layer PCB; 31. First-stage output capacitor; 311. First housing; 4. Second-stage output inductor; 41. Filter output terminal; 411. Mounting bracket; 412. Output port; 413. Connecting copper busbar; 42. Second magnetic core; 43. Second input pin; 44. Output copper busbar; 441. Connecting screw hole; 5. Third-layer PCB; 51. Second-stage output capacitor; 511. Second housing; 6. Winding; 7. Primary-side power switch transistor; 8. Transformer; 9. Secondary-side switch transistor; 10. Chassis. Detailed Implementation

[0033] To make the technical problem to be solved, the technical solution and the beneficial effects of the present invention clearer, the following description is provided in conjunction with the appendix. Figures 1-4 The principles and structure of the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0034] Please refer to the following: Figures 1-4 This invention provides a multilayer filter, comprising: N PCB layers spaced apart from top to bottom, where N is greater than or equal to 3; N-1 stages of output inductors spaced apart from top to bottom, each stage of output inductor being connected to adjacent upper and lower PCB layers via its input and output terminals respectively; N-1 stages of output capacitors spaced apart from top to bottom, each stage of output capacitor being connected to the second to Nth PCB layers respectively; and a filter output terminal 41 connected to the output terminal of the N-1th stage output inductor.

[0035] Please see Figure 1 This is a schematic diagram of a typical DC-DC circuit topology with primary and secondary isolation, a full-bridge topology. It includes a primary-side power switch 7, a transformer 8, a secondary-side switch 9, a first-stage output inductor 1, a first-stage output capacitor 31, a second-stage output inductor 4, and a second-stage output capacitor 51. Because the DC-DC output voltage is around 14V and the output power is 2-3KW or higher, the output current of DC-DC circuits is generally quite large, around one or two hundred amps or even higher. This invention proposes the design of a filter for the high-current path on the output side of the DC-DC circuit topology, namely... Figure 1 The part shown in the dashed box consists of the first-stage output inductor 1, the first-stage output capacitor 31, the second-stage output inductor 4, and the second-stage output capacitor 51.

[0036] Please refer to the following: Figures 1-4In Embodiment 1 provided by the present invention, when N equals 3, the input and output terminals of the first-stage output inductor 1 are respectively connected to the first layer PCB2 and the second layer PCB3, the input and output terminals of the second-stage output inductor 4 are respectively connected to the second layer PCB3 and the third layer PCB5, the first-stage output capacitor 31 and the second-stage output capacitor 51 are respectively connected to the second layer PCB3 and the third layer PCB5, and the filter output terminal 41 is connected to the output terminal of the second-stage output inductor 4.

[0037] Please see Figure 2 , 3 In this embodiment, the first-stage output inductor 1 includes a first magnetic core 11 and at least two windings 6 disposed within the first magnetic core 11 and connected in parallel. The top mounting surface of the first magnetic core 11 has a first input pin 12 and an output pin 13. The end of the first input pin 12 furthest from the first magnetic core 11 is higher than the end of the output pin 13 furthest from the first magnetic core 11. The first input pin 12 and the output pin 13 are respectively connected to the first layer PCB 2 and the second layer PCB 3. The top mounting surface of the first magnetic core 11 abuts against the bottom surface of the second layer PCB 3. In other embodiments, there are three or more windings 6 within the first magnetic core 11 connected in parallel. A certain height difference is formed between the first input pin 12 and the output pin 13, allowing them to be soldered onto PCBs of different layers. Finally, together with the external first magnetic core 11 and the core holder 14 or housing of the first magnetic core 11, a complete first-stage output inductor 1 is formed.

[0038] In a preferred embodiment, the two parallel windings 6 of the first-stage output inductor 1 are both formed by winding multiple turns of flat copper busbars, while the winding 6 of the second-stage output inductor 4 is formed by winding a single-turn copper busbar. Analysis of the operating characteristics of the devices at various locations in the circuit topology shows that the first-stage output inductor 1 contains a certain switching frequency current component and requires a relatively large inductance. Therefore, a thin copper sheet is used to wind multiple turns to form the winding 6, which is then connected in parallel to increase the inductance and reduce the skin effect. The switching frequency component in the second-stage output inductor 4 is relatively small and can be essentially ignored, while the inductance requirement is relatively small. Therefore, a copper busbar is used to form a single-turn inductor winding 6.

[0039] Please see Figure 2 , 3 In this embodiment, the first-stage output capacitor 31 includes: at least one first housing 311 mounted on the bottom surface of the second-layer PCB3 and a capacitor element disposed within the first housing 311; as a preferred embodiment, the first-stage output capacitor 31 includes two first housings 311 mounted on the bottom surface of the second-layer PCB3.

[0040] Please see Figure 2 , 3In this embodiment, the second-stage output inductor 4 includes a second magnetic core 42 and a winding 6 disposed within the second magnetic core 42. The top surface of the second magnetic core 42 has a second input pin 43, and the bottom surface of the second magnetic core 42 has an output copper busbar 44. The second input pin 43 and the output copper busbar 44 are respectively connected to the second layer PCB3 and the third layer PCB5. According to the actual structural matching requirements, the second input pin 43 and the output copper busbar 44 can form a flexible height difference and matching method to connect the front and rear stages, and the second magnetic core 42 is fitted over the copper busbar winding 6 to ultimately form the second-stage output inductor 4.

[0041] In this embodiment, the second-stage output capacitor 51 includes: a second housing 511 mounted on the bottom surface of the third-layer PCB 5 and a capacitor element within the second housing 511;

[0042] Please see Figure 2 , 3 In this embodiment, the filter output terminal 41 is connected to the output copper busbar 44. In a preferred embodiment, the output copper busbar 44 is W-shaped, with one end vertically connected to the bottom surface of the second magnetic core 42, and the other end passing through the third PCB 5 and attached to the bottom surface of the third PCB 5. The first input pin 12 passes through the second PCB 3 and is soldered to the first PCB 2, while the output pin 13 and the second input pin 43 are soldered to the second PCB 3. In other embodiments, the output copper busbar 44 may also be L-shaped or other shapes.

[0043] In this embodiment, the filter output terminal 41 includes: a mounting base 411, an output port 412 located at one end of the mounting base 411, and a connecting copper busbar 413 located at the other end of the mounting base 411. The connecting copper busbar 413 has a mounting screw hole at one end away from the mounting base 411, and the other end of the output copper busbar 44 has a connecting screw hole 441 that matches the mounting screw hole. The filter output terminal 41 is threaded to the output copper busbar 44 by a fixing screw passing through the mounting screw hole and the connecting screw hole 441.

[0044] In other embodiments, the above-mentioned welding and threaded connections can be replaced by ordinary welding, resistance welding, laser welding, screw connection, riveting connection, etc., depending on the specific circumstances of the connection point.

[0045] In Embodiment 2 of the present invention (not shown in the figure), when N equals 4, the input and output terminals of the first-stage output inductor 1 are respectively connected to the first layer PCB2 and the second layer PCB3, the input and output terminals of the second-stage output inductor 4 are respectively connected to the second layer PCB3 and the third layer PCB5, the first-stage output capacitor 31 and the second-stage output capacitor 51 are respectively connected to the second layer PCB3 and the third layer PCB5, and the filter output terminal 41 is connected to the output terminal of the second-stage output inductor 4; the input and output terminals of the third-stage output inductor are respectively connected to the second layer PCB3 and the third layer PCB5, the input and output terminals of the fourth-stage output inductor are respectively connected to the third layer PCB5 and the second layer PCB3, the fourth-stage output capacitor is connected to the fourth layer PCB, and the filter output terminal 41 is connected to the output terminal of the third-stage output inductor.

[0046] In other embodiments (not shown in the figures), N may also be equal to 5 or a value higher than 5.

[0047] Please see Figure 4 The present invention also provides an on-board power supply DC-DC converter, including a housing 10, and the aforementioned multi-layer filter mounted on the housing 10, a power switch, a transformer 8 and a secondary switch 9 connected to the first layer PCB2.

[0048] In this embodiment, the housing 10 forms a cavity (not shown) between the first-stage output inductor 1 and the second-stage output inductor 4 to separate the shielding inductor.

[0049] In this embodiment, a heat-conducting element (not shown in the figure) is filled between the first-stage output inductor 1 and the second-stage output inductor 4 and the housing 10.

[0050] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multilayer filter, characterized in that, include: N layers of PCB are arranged at intervals from top to bottom, where N is greater than or equal to 3; N-1 stages of output inductors are arranged at intervals from top to bottom. Each stage of output inductor is connected to the adjacent upper and lower PCB layers through its input and output terminals respectively. N-1 stages of output capacitors are arranged at intervals from top to bottom, with each stage of output capacitor connected to the second to Nth layers of the PCB respectively; The filter output terminal is connected to the output terminal of the (N-1)th stage output inductor; When N equals 3, the input and output terminals of the first-stage output inductor are connected to the first and second PCB layers respectively, the input and output terminals of the second-stage output inductor are connected to the second and third PCB layers respectively, the first-stage output capacitor and the second-stage output capacitor are connected to the second and third PCB layers respectively, and the filter output terminal is connected to the output terminal of the second-stage output inductor. The first-stage output inductor includes: a first magnetic core and at least two windings disposed within the first magnetic core and connected in parallel with each other. The top mounting surface of the first magnetic core is provided with a first input pin and an output pin. The end of the first input pin away from the first magnetic core is higher than the end of the output pin away from the first magnetic core. The first input pin and the output pin are respectively connected to the first layer PCB and the second layer PCB. The top mounting surface of the first magnetic core abuts against the bottom surface of the second layer PCB. The first-stage output capacitor includes: at least one first housing mounted on the bottom surface of the second-layer PCB and a capacitor component disposed within the first housing; The second-stage output inductor includes: a second magnetic core and a winding disposed within the second magnetic core. The top surface of the second magnetic core is provided with a second input pin, and the bottom surface of the second magnetic core is provided with an output copper busbar. The second input pin and the output copper busbar are respectively connected to the second layer PCB and the third layer PCB. The second-stage output capacitor includes: a second housing mounted on the bottom surface of the third-layer PCB and capacitor components within the second housing; The filter output terminal is connected to the output copper busbar.

2. The multilayer filter as described in claim 1, characterized in that, When N equals 4, the input and output terminals of the third-stage output inductor are connected to the second and third PCB layers respectively, the input and output terminals of the fourth-stage output inductor are connected to the third and second PCB layers respectively, the fourth-stage output capacitor is connected to the fourth PCB layer, and the filter output terminal is connected to the output terminal of the third-stage output inductor.

3. The multilayer filter as described in claim 1, characterized in that, The winding of the first-stage output inductor is formed by winding multiple turns of copper busbar, while the winding of the second-stage output inductor is formed by winding a single-turn copper busbar.

4. The multilayer filter as described in claim 1, characterized in that, One end of the output copper busbar is vertically connected to the bottom surface of the second magnetic core, and the other end of the output copper busbar passes through the third PCB and is attached to the bottom surface of the third PCB. The first input pin passes through the second PCB and is soldered to the first PCB. The output pin and the second input pin are soldered to the second PCB.

5. The multilayer filter as described in claim 4, characterized in that, The filter output terminal includes: The mounting base has an output port at one end and a connecting copper busbar at the other end. The end of the connecting copper busbar away from the mounting base has a mounting screw hole, and the other end of the output copper busbar has a connecting screw hole that matches the mounting screw hole. The filter output terminal is connected to the output copper busbar by passing a fixing screw through the mounting screw hole and the connecting screw hole.

6. A vehicle-mounted power supply DC-DC converter, comprising a housing, characterized in that, It also includes a multi-layer filter as described in any one of claims 2-5 mounted on the housing, and a power switch, transformer, and secondary switch connected to the first-layer PCB.

7. The on-board power supply DC-DC converter as described in claim 6, characterized in that, The housing forms a cavity between the first-stage output inductor and the second-stage output inductor to separate the shielding inductor.

8. The on-board power supply DC-DC converter as described in claim 6, characterized in that, The first-stage output inductor and the second-stage output inductor are filled with thermal conductive material between themselves and the housing.

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