Power supply module

Abstract

The utility model provides a power supply module. The power supply module comprises a first layer, a second layer and a third layer, the first layer, the second layer and the third layer are sequentially arranged from top to bottom; the first layer comprises a power semiconductor and at least one high-voltage decoupling capacitor; the second layer comprises a PCB (Printed Circuit Board) substrate; the third layer includes a plurality of pins. The utility model provides a practical, effective and novel implementation mode for XPU power supply in an AI scene with increasingly increased power density, and realizes organic combination of dimensions such as heat, magnetism, electromagnetic interference, power, efficiency, pin arrangement convenience and the like by using the same rule and taking the top of the DCDC converter as a main heat dissipation way in various scenes.

Description

Technical Field

[0001] The utility model relates to the technical field of power modules, in particular to the technical field of heat dissipation of chip power modules. Background Art

[0002] With the vigorous development of artificial intelligence, the power of servers is getting higher and higher, causing the system's power supply voltage to rise from the traditional 12V to the popular 48V, and even to 400V in high-end scenarios (hereinafter, the DC input with a maximum input voltage exceeding 36V is collectively referred to as HVDC). The server's computing core XPU (collectively referred to as GPU, CPU, TPU, etc.) is also getting more and more powerful, but the voltage is getting lower and lower, and the voltage difference with the system input voltage is getting larger and larger. Therefore, the internal power supply of the server requires DCDC with HVDC input, which reduces the HVDC to the voltage required by the chip through multiple stages or a single stage, resulting in the demand for DCDC power modules of various specifications.

[0003] As power density requirements continue to increase, the size of DCDC power modules is getting smaller and smaller, which puts more stringent requirements on the cooling system. How to achieve a balance between power conversion efficiency, heat dissipation and electromagnetic compatibility has always been a technical challenge in this field. Utility Model Content

[0004] The utility model proposes a top heat dissipation DCDC power supply module based on a multi-layer thick copper PCB substrate. In a limited space, while having a good heat dissipation effect, it also takes into account power conversion efficiency and electromagnetic compatibility, thereby achieving a balance among power conversion efficiency, heat dissipation and electromagnetic compatibility.

[0005] The utility model provides a power supply module on one hand, comprising a first layer, a second layer and a third layer; the first layer, the second layer and the third layer are arranged in sequence from top to bottom;

[0006] The first layer includes power semiconductors and at least one high-voltage decoupling capacitor; the second layer includes a PCB substrate; the third layer includes a plurality of pins;

[0007] The power module also includes a magnetic core and a winding; the magnetic core includes at least two middle columns, at least one upper cover and at least one lower cover; the middle column, the upper cover and the lower cover form a closed magnetic circuit; wherein the upper cover is located on the first layer; the middle column is located on the second layer; the winding is formed by multiple layers of copper of the PCB substrate surrounding at least one middle column of the magnetic core; the winding includes at least three electrodes with different potentials, and the winding is at least two independent windings or at least two windings connected in series; at least two of the windings have a coupling coefficient of 50% or more;

[0008] The PCB substrate is a multi-layer thick copper PCB substrate; the PCB substrate is provided with at least two hollows to accommodate the center column of the magnetic core; the number of copper layers in the PCB substrate is greater than or equal to six layers, and the thickness of at least two layers of copper is greater than 50um;

[0009] The lower surface of the power semiconductor is connected to the upper surface of the PCB substrate, and the heat generated by the power semiconductor is greater than or equal to two-thirds of the total heat generated by the power module; the power semiconductor includes at least two power semiconductor switches, and the power semiconductor switches are connected in series to form a bridge arm, and the bridge arm includes at least two DC electrodes and one AC electrode; the operating frequency of the power semiconductor switch is greater than or equal to 500KHZ;

[0010] The high-voltage decoupling capacitor is arranged at the edge of the bridge arm on the upper surface of the PCB substrate, the high-voltage decoupling capacitor is connected in parallel with the two DC electrodes of the bridge arm, and the capacity of the high-voltage decoupling capacitor is at least 10nF;

[0011] One end of the pin is connected to the lower surface of the PCB substrate.

[0012] Furthermore, at least one of the hollow portions is disposed in the middle of the PCB substrate.

[0013] Furthermore, the heat generated by the power semiconductor is greater than or equal to three quarters of the total heat generated by the power module.

[0014] Furthermore, the operating frequency is 1 MHz;

[0015] Furthermore, the third layer also includes at least one low-voltage decoupling capacitor and / or at least one resonant capacitor, which are arranged on the lower surface of the PCB substrate, and the low-voltage decoupling capacitor and / or resonant capacitor are connected in series with at least one electrode of the winding.

[0016] Furthermore, the power module also includes an additional layer, the additional layer is located above the first layer, the additional layer includes a heat sink, and the upper surface of the power semiconductor is thermally connected to the lower surface of the heat sink.

[0017] Furthermore, the AC electrode of the bridge arm is directly connected to at least one electrode of the winding, and / or the AC electrode of the bridge arm is indirectly connected to at least one electrode of the winding via the low-voltage decoupling capacitor, so as to transfer the high-frequency energy of the AC electrode through the winding by magnetic coupling.

[0018] Furthermore, the third layer also includes a controller and a driver, and the driver is connected to the lower surface of the PCB substrate.

[0019] Furthermore, the power module also includes a fourth layer, the fourth layer is located below the third layer, the fourth layer includes a pin conversion board, and the controller is arranged on the upper surface of the pin conversion board.

[0020] Furthermore, the thickness of the upper cover is no more than 1.5 times the thickness of the power semiconductor.

[0021] Furthermore, the thickness of the upper cover is equal to the thickness of the power semiconductor.

[0022] Furthermore, the first layer also includes a heat conductive block, and the power semiconductor is provided with a heat conductive block near the power semiconductor. The heat conductive block is used to conduct the heat of the power semiconductor horizontally to the heat conductive block through the PCB substrate, and then to the upper surface of the power module.

[0023] Furthermore, the thickness of the heat conducting block is equal to the thickness of the upper cover.

[0024] Furthermore, the upper cover of the magnetic core is directly fixed to the upper surface of the PCB substrate by glue.

[0025] Furthermore, the upward thermal resistance of the power semiconductor is no more than 3 times the downward thermal resistance of the power semiconductor.

[0026] Furthermore, the upward thermal resistance of the power semiconductor is twice the downward thermal resistance of the power semiconductor.

[0027] Furthermore, it also includes a first group of output synchronous rectification units and a second group of output synchronous rectification units, wherein the first group of synchronous rectification units, the magnetic core, and the second group of synchronous rectification units are arranged in sequence from left to right and are arranged on one side of the low-voltage and high-current pins.

[0028] Furthermore, the magnetic core, the power semiconductor, and the high-voltage decoupling capacitor are arranged in sequence from left to right.

[0029] Compared with the prior art, the utility model has the following advantages:

[0030] The power module provided by the utility model proposes a practical and effective novel implementation method for XPU power supply in AI scenarios with increasing power density. In multiple scenarios, the same rule is used, with the top of the DCDC converter as the main heat dissipation path, to achieve an organic combination of heat, magnetism, electromagnetic interference, power, efficiency, and pin arrangement convenience. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, 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 utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 It is a structural schematic diagram of the cross section of the DCDC power module;

[0033] Figure 2 It is a schematic diagram of the main power topology of the power module;

[0034] Figure 3 A pin structure diagram of a power module;

[0035] Figure 4 It is another pin structure diagram of the power module;

[0036] Figure 5 It is a schematic diagram of the main power topology of the power module;

[0037] Figure 6 This is a schematic diagram of the main power topology of the power module. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0039] Figure 1 Figure 1 is a cross-sectional structural diagram of a DCDC power module. Figure 1 As shown, the structure of the power conversion core in the DCDC power module is sequentially provided with an additional layer 1, a first layer 2, a second layer 3, a third layer 4 and a fourth layer 5 from top to bottom; wherein the first layer 2, the second layer 3 and the third layer 4 constitute the power conversion core of the power module.

[0040] The additional layer 1 is provided with a heat sink 10, which is used to diffuse the heat generated by the power module from the top. Here, the specific type of the heat sink 10 is not limited.

[0041] The first layer 2, the second layer 3 and the third layer 4 constitute the power conversion core module of the power module, see Figure 1 The first layer 2 is provided with a power semiconductor 20 , a high-voltage decoupling capacitor 21 , and an upper cover 601 of a magnetic core 60 .

[0042] The power semiconductor 20 is a collection of a series of semiconductor elements. The power semiconductor 20 includes four power semiconductor switches (respectively Q1, Q2, Q3, Q4 (see Figure 2 ));

[0043] like Figure 2 As shown, Q1 and Q2 form one bridge arm, and Q3 and Q4 form another bridge arm. Due to volume limitations, the operating frequency fs of the power semiconductor switch is greater than or equal to 500KHZ, preferably greater than or equal to 1MHZ.

[0044] In addition, the power semiconductor 20 is arranged on the upper surface of the power module, and the heat generated by the power semiconductor 20 accounts for at least two-thirds of the total heat generated by the DCDC power module. The advantage of this layout is that the equivalent thermal resistance from the main heat source of the power module to the heat sink 10 is reduced, the heat dissipation capacity is greatly enhanced, and the power of the power module can be greatly improved. Figure 2 , components accounting for two-thirds of the total heat generated by Q1, Q2, Q3, Q4, SR1, SR2, SR3, and SR4 are arranged on the top surface of the PCB, preferably more than three-quarters.

[0045] Preferably, the first layer 2 further includes a high voltage decoupling capacitor 21 ( Figure 2 Cin), the capacity of the high-voltage decoupling capacitor is at least 10nF. Figure 2 As shown, the high-voltage decoupling capacitor 21 is connected in parallel to the two DC electrode ends of the bridge arm to eliminate the voltage spike during the high-frequency switching process of the power semiconductor of the bridge arm and reduce high-frequency electromagnetic interference.

[0046] Furthermore, the high-voltage decoupling capacitor 21 is arranged close to the edge of the bridge arm on the upper surface of the PCB substrate 30 (ideally close to it) to minimize high-frequency loops, reduce bridge arm voltage spikes, and reduce electromagnetic interference, so that the power semiconductor 20 can switch at a faster speed, reduce switching losses, increase switching frequency or power, and thus increase power density.

[0047] The second layer 3 includes a PCB substrate 30; the PCB substrate 30 is a multi-layer thick copper PCB substrate;

[0048] The power module also includes a magnetic core 60 and a winding; wherein the magnetic core includes a first center column 603, a second center column 604, an upper cover 601 and a lower cover 602; the first center column 601, the second center column 602, the upper cover 601 and the lower cover 602 form a closed magnetic circuit; wherein the upper cover 601 is located on the first layer 2, and the lower cover 602 is located on the third layer 4; the first center column 603 and the second center column 604 are located on the second layer 3, or the main body of the first center column 603 is located on the second layer 3, and the two ends extend to the first layer 2 and the third layer 4 respectively; the second center column 604 adopts the same layout as the first center column 603. To further reduce the upward thermal resistance, the upper cover 601 of the magnetic core 60 is directly fixed to the upper surface of the PCB substrate 30 by glue, so as to reduce the distance from the upper surface of the PCB substrate 30 to the upper surface of the upper cover 601 of the magnetic core 60 as much as possible, so that the upper surface of the power semiconductor 20 placed on the upper surface of the PCB substrate 30 is closer to the heat sink 10, thereby reducing the thermal resistance. The dimensional tolerance of the magnetic core 60 can be flexibly absorbed by the gap between the lower surface of the PCB substrate 30 and the lower cover 602 of the magnetic core 60, so it does not affect the difficulty of manufacturing.

[0049] Optionally, the thickness of the upper cover 601 of the magnetic core 60 does not exceed 1.5 times the thickness of the power semiconductor 20, and is preferably nearly equal, so that the upper surfaces of the heat sources (magnetic core 60 and power semiconductor 20) on the upper surface of the PCB substrate 30 are almost on the same plane, at the same distance from the heat sink, with small thermal resistance and uniform distribution.

[0050] Furthermore, the upward thermal resistance of the power semiconductor 20 on the upper surface of the PCB substrate 30 is not greater than 3 times, preferably not greater than 2 times, of its downward thermal resistance, thereby further reducing the thermal resistance from the power semiconductor to the heat sink.

[0051] Optionally, a heat conducting block 22 may be provided in the first layer 2, see Figure 1 A heat conducting block 22 is arranged near the power semiconductor 20, preferably close to the power semiconductor 20, and the heat of the power semiconductor 20 is firstly conducted to the heat conducting block 22 laterally through the PCB substrate 30, and then conducted to the upper surface of the power module by the heat conducting block 22, and then diffused by the heat sink 10. It is best that the thickness of the heat conducting block 22 is equal to or close to that of the upper cover 601 of the magnetic core 60, so as to reduce the thermal resistance to the extreme.

[0052] Winding( Figure 1 Not shown, Figure 2 W1, W21, W22, W31, and W32 are all windings) formed by multiple layers of copper on the PCB substrate 30 surrounding the first middle column 603 and the second middle column 604 in the magnetic core 60; and the winding includes three electrodes with different potentials. Using the multiple layers of copper in the PCB substrate 30 as windings can achieve automated production with extremely high consistency and near-ultimate space utilization.

[0053] Preferably, at least two of the windings have a coupling coefficient of at least 50% to achieve a richer conversion capability of the circuit.

[0054] Furthermore, at least two hollow portions are provided on the PCB substrate 30 to respectively accommodate the first middle column 603 and the second middle column 604 of the magnetic core 60 .

[0055] The lower surface of the power semiconductor 20 is connected to the upper surface of the PCB substrate 30; the upper surface of the power semiconductor 20 is connected to the lower surface of the heat sink 10. Preferably, the power semiconductor 20 is connected to the heat sink 10 via a thermally conductive filler; the power semiconductor 20 is connected to the PCB substrate 30 via a PCB fixing glue.

[0056] Preferably, the number of copper layers in the PCB substrate 30 is at least 6, and the thickness of at least 2 of the copper layers is greater than 50 um.

[0057] At the same time, the upper and lower surfaces of the PCB have corresponding pads for surface mounting, which are used to solder corresponding electronic components. Due to space limitations, the use of multi-layer thick copper PCB substrates can effectively ensure the passage of large currents and reduce losses.

[0058] Optionally, at least one of the two hollowings is located in the middle of the PCB substrate 30 , and the other hollowing can be set in the middle of the PCB substrate 30 or at an edge of the PCB substrate 30 .

[0059] The third layer 4 includes a low voltage decoupling capacitor ( Figure 2 Co) and two resonant capacitors ( Figure 2 In the embodiment, there is a set of Cr) 41, a driver 42, a controller 43 and multiple power pins 40.

[0060] like Figure 1 The low-voltage decoupling capacitor Co, the resonant capacitor Cr, and the driver 42 of the power semiconductor 20 are arranged on the lower surface of the PCB substrate 30. This design can place as many heat sources as possible (devices that generate more heat than the above devices) on the upper surface of the PCB, thereby achieving stronger heat dissipation capabilities and improving the power of the power module. In addition, the driver 42 is far away from the power wiring, which can effectively reduce the possibility of electromagnetic interference.

[0061] Optionally, the controller 43 is disposed on the upper surface of the power conversion board 50. Such a design is to leave more space on the thick copper multi-layer PCB substrate 30 for power conversion devices, thereby increasing power, that is, power density.

[0062] A plurality of power pins 40 are disposed below the PCB substrate 30 and are responsible for inputting or outputting energy to the application system. Figure 2The power pin includes at least two electrodes among Vin+, Vin-, Vo+, and Vo-.

[0063] A pin conversion board 50 is provided in the fourth layer 5 to convert the power pins 40 into a PCBSMD Pad with a more flexible configuration.

[0064] Furthermore, more electronic components, such as a controller 43 with less heat generation, can be arranged on the surface of the pin conversion board 50 facing the PCB substrate 30, so that the PCB substrate 30 has more resources left for power conversion, thereby improving power, that is, power density.

[0065] Figure 2 The main power topology of the DCDC power module is shown in FIG. Figure 2 The isolated circuit shown in the figure, wherein Q1 and Q2 form one bridge arm, and Q3 and Q4 form another bridge arm; the AC electrode of the bridge arm is directly connected to at least one electrode of the winding, and the AC electrode of the bridge arm is indirectly connected to at least one electrode of the winding through a low-voltage decoupling capacitor, so as to transfer the high-frequency energy of the AC electrode through the winding by magnetic coupling. Figure 2 , Q1 and Q2 in the bridge arm are indirectly connected to the winding through the resonant capacitor Cr, and the bridge arm Q3 and Q4 are directly connected to the winding; W1, W21, W22, W31, and W32 are all the windings, and each winding is arranged on the PCB substrate 30 and is coupled to each other through the magnetic core;

[0066] The isolated circuit may adopt an LLC or PWM bridge circuit, wherein the primary power semiconductor and the secondary power semiconductor do not need to be electrically connected to achieve main power conversion.

[0067] It should be noted that the five-layer structure is used as an example here, but it is not limited to this. In fact, the windings in the power conversion core of the power module are arranged on the first to third layers, and the additional layers and the fourth layer can be flexibly increased or decreased according to actual needs.

[0068] Figure 3 Figure 2 shows a schematic diagram of the pin structure of the DCDC power module. Figure 3 As shown, the pin structure includes multiple pins (pin 2 to pin 7, pin 9 to pin 18), and the power module is rectangular; the power pins for low voltage and high current output are arranged on one of the long sides, such as Figure 313 to 18 pins. The magnetic core is placed in the center of the PCB substrate 30. In addition, it includes at least two groups of output synchronous rectification units: SR1+SR2 is the first group of synchronous rectification units, and SR3+SR4 is the second group of synchronous rectification units. The first group of synchronous rectification units, the magnetic core, and the second group of synchronous rectification units are arranged in sequence from left to right, and are close to the low-voltage and high-current pin side to minimize the high-current path and loss. In addition, the two groups of synchronous rectification are divided into two sides of the magnetic core, which is conducive to realizing a short and wide path for each, and achieving high efficiency under high current.

[0069] Furthermore, on the input side of the pin structure (i.e. Figure 3 The lower side of the magnetic core is provided with power semiconductors, such as Figure 3 Q1~Q4 in the circuit are set to the side away from the low voltage and high current pins (i.e. Figure 3 The lower side of the magnetic core in the middle) is designed to allow as much open space as possible for low-voltage, high-current rectification and magnetic components, reducing losses and increasing power. Thanks to the isolated circuit, there is no need for electrical connection between the primary and secondary power semiconductors, and they can be placed freely. Also, because there is no direct energy transfer between the primary and secondary sides, all energy is transferred through magnetic coupling, so it is particularly suitable for scenarios with large input and output voltage differences. For example, the voltage ratio between the high-voltage side and the low-voltage side is greater than or equal to 8 times.

[0070] More specifically, the utility model is applied to a 48Vin8:1 converter (i.e., the voltage ratio between the high-voltage side and the low-voltage side is 8 times) with a size of 27 (L) * 18 (W) * 6.7 (H) mm. Thanks to the utility model's organic combination of top heat dissipation, power device layout, electromagnetic interference, and power pins, it can stably operate at a high power of 600W and achieve a transient power of 900W, with a maximum efficiency of 97.5%, and the comprehensive indicators far exceed the existing technology.

[0071] On the other hand, the topology circuit was further optimized. Figure 4 Another pin structure is shown. Figure 5 The corresponding circuit topology diagram is shown.

[0072] like Figure 4 As shown, the magnetic core is arranged next to the right side of the pin structure, and the right side of the magnetic core is divided into two columns. The first column is sequentially arranged with Q2, SR1, SR2 and Q4 from top to bottom, and the second column is sequentially arranged with Q1 and Q3 from top to bottom, and Q1 and Q2 are on the same horizontal line, and Q4 and Q3 are on the same horizontal line.

[0073] and, Figure 4The high-voltage decoupling capacitor is placed on the other side opposite to the magnetic core. That is, the magnetic core, power semiconductor, and high-frequency capacitor are arranged in sequence. The advantage of this is that the distance between the power semiconductor bridge arm and the magnetic element winding and the power semiconductor bridge arm and the high-frequency capacitor is shortened at the same time. The space is used to the extreme to achieve the highest efficiency and power density.

[0074] See also Figure 5 When there are two bridge arms, the first bridge arm Q1, Q2 and SR1 are placed above one side of the magnetic core, and the other bridge arm Q3, Q4 and SR2 are placed below, so that the two bridge arms are symmetrically connected to the winding lead-out ends of the magnetic element nearby, further reducing losses.

[0075] See again Figure 5 Since the system input voltage is less than 100V, especially 60V, the input and output do not need safety isolation. In order to improve the efficiency of the circuit and increase the power density, the input switch elements (Q1~Q4) of the main circuit and the output synchronous rectification elements (SR1 and SR2) are electrically connected in series to form a bridge arm composed of at least three power semiconductors.

[0076] on the other hand, Figure 6 Shows Figure 3 Another topological circuit diagram of the pin structure, Figure 6 The circuit shown is Figure 5 The circuits described differ in that: Figure 5 With independent primary winding, Figure 6 The circuit shown does not have a clear distinction between primary and secondary windings, but all have at least two windings.

[0077] Since there is a component of direct energy transfer between the input and output and it is not entirely magnetically coupled, it is more suitable for situations where the input and output pressures are relatively low, such as when the high-voltage side is not higher than 7 times the low-voltage side.

[0078] On the other hand, the utility model achieves the following specifications: in the case of a one-pin conversion board, in the scenario of 23 (L) * 17 (W) * 7.7 (H) mm, 48Vin 4:1 converter, stable power 1000W, transient power 2700W, maximum efficiency 98.2%, and comprehensive indicators are much higher than the existing technology. This is also due to the organic combination of top heat dissipation, power device layout, electromagnetic interference, and power pins in the utility model.

[0079] On the other hand, the utility model achieves the following specifications: under the condition of stable output voltage adjustment, in the scenario of 58.4 (L) * 36.8 (W) * 12.7 (H) mm, 40 ~ 60Vin, 12Vo converter, stable power 1600W, transient power 2400W, maximum efficiency 98.5%, and comprehensive indicators are much higher than the existing technology. This is also due to the organic combination of top heat dissipation, power device layout, electromagnetic interference, and power pins in the utility model.

[0080] In summary, the utility model sets the magnetic core on one side of the module PCB, freeing up the concentrated area on the other side of the PCB for placing most of the power semiconductors. This makes the high-frequency and high-current series loops of the primary MOS and secondary MOS of each circuit as small as possible, reduces electromagnetic interference and shortens the current path, and improves efficiency and power density. Figure 3 When there are two bridge arms, the first bridge arm is placed above one side of the magnetic core, and the other bridge arm is placed below the same side of the magnetic core, so that the two bridge arms are symmetrically connected to the winding lead-out ends of the magnetic element nearby, further reducing losses.

[0081] The "equal" or "same" or "equal" disclosed in the present invention must take into account the parameter distribution of the project, and the error distribution is within ±30%; the definition of "parallel" of two line segments or two straight lines is that the angle between the two line segments or two straight lines is less than or equal to 45 degrees; the definition of "perpendicular" of two line segments or two straight lines is that the angle between the two line segments or two straight lines is within the range of [60, 120] degrees; the definition of "phase mismatch" also needs to take into account the parameter distribution of the project, and the error distribution of the degree of mismatch is within ±30%. In addition, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. Without more constraints, an element defined by the phrase "comprising a..." does not exclude the existence of other identical elements in the process, method, article or apparatus comprising the element.

[0082] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0083] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power module, characterized in that: It comprises a first layer, a second layer and a third layer; the first layer, the second layer and the third layer are arranged in sequence from top to bottom; The first layer includes power semiconductors and at least one high-voltage decoupling capacitor; the second layer includes a PCB substrate; the third layer includes a plurality of pins; The power module also includes a magnetic core and a winding; the magnetic core includes at least two middle columns, at least one upper cover and at least one lower cover; the middle column, the upper cover and the lower cover form a closed magnetic circuit; wherein the upper cover is located on the first layer; the middle column is located on the second layer; the winding is formed by multiple layers of copper of the PCB substrate surrounding at least one middle column of the magnetic core; the winding includes at least three electrodes with different potentials, and the winding is at least two independent windings or at least two windings connected in series; at least two of the windings have a coupling coefficient of 50% or more; The PCB substrate is a multi-layer thick copper PCB substrate; the PCB substrate is provided with at least two hollows to accommodate the center column of the magnetic core; the number of copper layers in the PCB substrate is greater than or equal to six layers, and the thickness of at least two layers of copper is greater than 50um; The lower surface of the power semiconductor is connected to the upper surface of the PCB substrate, and the heat generated by the power semiconductor is greater than or equal to two-thirds of the total heat generated by the power module; the power semiconductor includes at least two power semiconductor switches, and the power semiconductor switches are connected in series to form a bridge arm, and the bridge arm includes at least two DC electrodes and one AC electrode; the operating frequency of the power semiconductor switch is greater than or equal to 500KHz; The high-voltage decoupling capacitor is arranged at the edge of the bridge arm on the upper surface of the PCB substrate, the high-voltage decoupling capacitor is connected in parallel with the two DC electrodes of the bridge arm, and the capacity of the high-voltage decoupling capacitor is at least 10nF; One end of the pin is connected to the lower surface of the PCB substrate.

2. The power module according to claim 1, characterized in that: At least one of the hollow portions is disposed in the middle of the PCB substrate.

3. The power module according to claim 1, wherein: The heat generated by the power semiconductor is greater than or equal to three quarters of the total heat generated by the power module.

4. The power module according to claim 1, wherein: The operating frequency is 1 MHz.

5. The power module according to claim 1, wherein: The third layer further comprises at least one low voltage decoupling capacitor and / or at least one resonant capacitor, which are arranged on the lower surface of the PCB substrate, and the low voltage decoupling capacitor and / or the resonant capacitor are connected in series with at least one electrode of the winding.

6. The power module according to claim 1, wherein: An additional layer is also included, the additional layer being located above the first layer, the additional layer including a heat sink, the upper surface of the power semiconductor being thermally connected to the lower surface of the heat sink.

7. The power module according to claim 1, wherein: The AC electrode of the bridge arm is directly connected to at least one electrode of the winding, and / or the AC electrode of the bridge arm is indirectly connected to at least one electrode of the winding via a low-voltage decoupling capacitor, so as to transfer the high-frequency energy of the AC electrode through the winding by magnetic coupling.

8. The power module according to claim 1, wherein: The third layer also includes a controller and a driver, and the driver is connected to the lower surface of the PCB substrate.

9. The power module according to claim 8, characterized in that: It also includes a fourth layer, which is located below the third layer. The fourth layer includes a pin conversion board, and the controller is arranged on the upper surface of the pin conversion board.

10. The power module according to claim 1, wherein: The thickness of the upper cover is no more than 1.5 times the thickness of the power semiconductor.

11. The power module according to claim 1, wherein: The thickness of the upper cover is equal to the thickness of the power semiconductor.

12. The power module according to claim 1, wherein: The first layer also includes a heat conductive block, and the power semiconductor is provided with a heat conductive block near the power semiconductor. The heat conductive block is used to conduct the heat of the power semiconductor horizontally through the PCB substrate to the heat conductive block first, and then to the upper surface of the power module.

13. The power module according to claim 12, wherein: The thickness of the heat conducting block is equal to the thickness of the upper cover.

14. The power module according to claim 1, wherein: The upper cover of the magnetic core is directly fixed to the upper surface of the PCB substrate by glue.

15. The power module according to claim 1, wherein: The upward thermal resistance of the power semiconductor is no more than 3 times the downward thermal resistance of the power semiconductor.

16. The power module according to claim 15, characterized in that: The upward thermal resistance of the power semiconductor is twice the downward thermal resistance of the power semiconductor.

17. The power module according to claim 1, wherein: It also includes a first group of output synchronous rectification units and a second group of output synchronous rectification units, wherein the first group of synchronous rectification units, the magnetic core, and the second group of synchronous rectification units are arranged in sequence from left to right and are arranged on one side of the low-voltage and high-current pins.

18. The power module according to claim 17, wherein: The magnetic core, the power semiconductor, and the high-voltage decoupling capacitor are arranged in sequence from left to right.

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