TWI868566B - Sandwich structure power supply module - Google Patents

Abstract

A sandwich structure power supply module includes stacked inductor pact, PCBs and power device chips. The inductor pack includes a magnetic core and windings. The magnetic core is covered by two pairs of metal layers for connecting to power pins of the power device chips via the PCBs. Compared to the prior art module structure, the disclosed power supply module saves PCB (Printed Circuit Board) footprint, and improves load current/power density. Meanwhile, the disclosed power supply module minimizes the output current trace impedance on PCB and mainly delivers output current through inductor legs to achieve high-efficiency.

Description

Sandwich structure power module

The disclosed embodiments relate to electronic components, and more specifically, the present invention relates to a power module structure.

Generally, a power converter is used to convert input power into output power with appropriate voltage and current for the load. A multiphase power converter includes multiple power stages connected in parallel and working in staggered phases, so it has the advantages of small output voltage ripple, fast transient response, and low rated ripple current requirement for input capacitors. Due to the above advantages, multiphase power converters are widely used in applications with large output current and low voltage, such as servers, microprocessors, etc.

The rapid development of modern GPUs (graphics processing units) and CPUs (central processing units) has put forward higher and higher requirements on the current capability of multi-phase power converters. At the same time, the size of these processors is getting smaller and smaller, which means that the size of multi-phase power converters needs to be reduced accordingly. The increasing current and decreasing size have made the heat dissipation of multi-phase power converters more challenging. In other words, a power converter with high current density, high efficiency and excellent heat dissipation capability is needed.

The purpose of the present invention is to provide a power module with a sandwich structure, which is used to stack and integrate the inductor, power switch and driver in the power circuit system into a smaller module.

According to one embodiment of the present invention, an inductor group for a power module includes: a magnetic core having a symmetrical structure in a top view, and having two channels penetrating the magnetic core from top to bottom and distributed on both sides of the central axis of the top view surface of the magnetic core, and two coils passing through the two channels of the magnetic core respectively, wherein each coil has a first end and a second end, and at least one of the first end and the second end is bent and extended on a plane perpendicular to the length of the coil.

A power module according to an embodiment of the present invention includes the aforementioned inductor group, and also includes: a PCB top board located on the inductor group; and two power device chips located on the PCB top board, wherein the two power device chips each have at least one pin electrically connected to a corresponding coil through the PCB top board.

In one embodiment, the power module further includes a PCB bottom plate, located below the inductor group; and a connector, connecting the PCB top plate and the PCB bottom plate, wherein the connector has a plurality of metal pillars, which are respectively welded to corresponding pads of the PCB top plate and the PCB bottom plate.

The power module with sandwich structure of the present invention has the following advantages: (1) compared with the power module with flat structure in the prior art, it can reduce the area on the PCB board, thereby improving the load current/power density; (2) by transmitting the output current through the legs (coils) of the inductor, it can reduce the routing of the output current loop on the PCB board and avoid the high impedance of the PCB board routing, thereby improving the circuit efficiency; and (3) the structure of the power module of the present invention with the power device chip on the top and the inductor group on the bottom can greatly benefit from the top cooling system commonly used in GPU, CPU and ASIC systems.

In the following description, some specific details, such as the specific circuit structures in the embodiments and the specific parameters of these circuit elements, are used to provide a better understanding of the embodiments of the present invention. Those skilled in the art can understand that the embodiments of the present invention can be implemented even in the absence of some details or in the combination of other methods, elements, materials, etc. In addition, the meaning of "coupled" referred to herein is directly connected or indirectly connected through other circuit elements.

The embodiments described below will use specific implementation devices and application backgrounds as examples to illustrate the devices and working methods of various embodiments of the present invention, so that those skilled in the art can better understand the present invention. However, those skilled in the art should understand that these descriptions are only exemplary and are not intended to limit the scope of the present invention.

FIG1 shows a schematic diagram of the circuit structure of an existing multi-phase power converter 10. As shown in FIG1 , the multi-phase power converter 10 includes a controller 101, N power devices 103 and N inductors L1, where N is an integer and N>1. As shown in FIG1 , each power stage 102, also referred to as each phase 102, includes a power device 103 and an inductor L1. Each power device 103 includes power switches M1, M2 and a driver DR1 for driving the power switches M1, M2. The controller 101 provides N-phase control signals 105-1~105-N to control the N power devices 103 respectively to control the N phases 102 to work out of phase, that is, the N inductors L1 draw energy from the input end in turn and provide energy to the load 104 in turn. It should be understood that in FIG1 , the outputs of each phase of the multi-phase power converter 10 are connected together to provide energy to the load, which is only one application. In other applications, the multi-phase power converter 10 can also work in the manner of multiple single-phase power converters, that is, each phase can be connected to an independent load separately and provide different output voltages to meet the requirements of different loads.

The power stage 102 with the BUCK topology shown in FIG1 is only an example. A person skilled in the art should understand that power stages with other topologies are also applicable to the multi-phase power converter of the embodiment of the present invention.

In the following embodiments of the present invention, the inductor L1 may be implemented by a coupled inductor or by N single inductors.

When N=2, the multi-phase power converter 10 is used as a dual-phase power converter, or two independent power converters.

FIG2 shows a schematic diagram of a power module 20 with a sandwich structure that integrates a dual-phase power converter according to an embodiment of the present invention. In FIG1 , when N=2, the power stage 102 can be implemented by the power module 20. The power module 20 with a sandwich structure includes: a printed circuit board (PCB) bottom plate 201, located at the bottom of the power module 20; an inductor group 206, located on the PCB bottom plate 201, including two inductors, wherein each inductor has a first end and a second end; a PCB top plate 202, located on the inductor group 206; a connector 204, having a plurality of metal pillars 205, each metal pillar 205 being soldered to corresponding pads on the PCB top plate 202 and the PCB bottom plate 201; and Two power device chips 203 are located on the top of the PCB top board 202, wherein each power device chip 203 has one or more pins connected to the second end of the inductor in the inductor group 206 through the PCB top board 202; wherein each inductor has a coil 207, and the two ends of the coil 207 are bent to a plane perpendicular to the length direction of the coil 207 and extend on the PCB top board 202 and the PCB bottom board 201.

In FIG2 , the power module 20 further includes other components 208 that are separately arranged on the PCB top board 202. The components 208 include, for example, various resistors, capacitors, etc. in the power converter 10, such as an input capacitor for providing a pulse current at the input end of the power converter 10, and filter capacitors and resistors for supplying power to the power switch driver and the internal logic circuit.

In one embodiment, the metal pillar 205 includes a copper pillar for soldering the PCB bottom plate 201 to the PCB top plate 202. A person skilled in the art should understand that any metal pillar that can be used to electrically connect two PCB boards can be used in the present invention.

The power module 20 is usually placed on the mainboard of the processor to provide power to the components on the mainboard. The PCB base plate 201 is welded on the mainboard, and some pins of the power module 20 are welded to the mainboard through the PCB base plate 201. In some embodiments, the PCB base plate 201 can also be omitted. The power module 20 can be directly welded to the mainboard through the connector 204 and the inductor group 206.

In the present invention, the power device chip is stacked on the inductor group, as shown in FIG2, thereby saving the area of the power converter 10 on the PCB board. Each power device chip 203 integrates the power device 103 shown in FIG1, that is, including the power switches M1 and M2 shown in FIG1 and the driver DR1 used to drive the power switches M1 and M2, as well as the circuit connected to the auxiliary coil not shown in FIG1. The pins of the power device chip 203 are soldered to the pads of the PCB top board 202, and then the pads of the PCB top board 202 are electrically connected to the pads of the PCB bottom board 201 through the inductor group 206 and the connector 204. In this way, the power device chip 203 can be electrically connected through the PCB bottom board 201. The power module 20 also includes a metal sheet 209 for conducting large current signals such as reference ground. The metal sheet 209 wraps a portion of the magnetic core of the inductor group 206 and is welded to the PCB top plate 202 and the PCB bottom plate 201 at the same time. The position of the metal sheet 209 depends on the position of the ground pin of the power device chip 203. In the embodiment of Figure 2, the metal sheet 209 is mainly wrapped around the side of the inductor group 206, and its two ends are bent to form welding areas close to the corresponding pads on the PCB board on the upper and lower surfaces of the inductor group 206, so that on the horizontal plane, that is, the plane of the PCB board, a large area of the metal sheet 209 is used to replace the PCB wiring to carry large current, reduce circuit loss, and improve circuit efficiency.

FIG3 shows a three-dimensional exploded view of an inductor assembly 30 according to an embodiment of the present invention. The inductor assembly 30 can be used as the inductor assembly 206 in the power module of FIG2. As shown in FIG3, the inductor assembly 30 includes: a magnetic core, including a first magnetic core portion 301 and a second magnetic core portion 302, wherein the first magnetic core portion 301 and the second magnetic core portion 302 are combined together to form two channels 303-1 and 303-2 at the joint surface of the first magnetic core portion 301 and the second magnetic core portion 302; and coils 304-1 and 304-2, passing through the channels 303-1 and 303-2 respectively.

In the embodiment of FIG. 3 , when the inductor assembly 30 is applied to the power module 20 shown in FIG. 2 , the channels 303 - 1 and 303 - 2 are parallel to the PCB bottom plate 201 and the PCB top plate 202 , that is, the channels 303 - 1 and 303 - 2 have a radial direction along the axis “A” shown in FIG. 2 .

In the embodiment of FIG. 3 , the coil 304-1 has a first end 304-3 bent 90 degrees and extending on the surface of the magnetic core, and covering a part of the surface. The extended part is also equivalent to extending on the surface of the PCB top board 202 and soldered to the PCB top board 202. The coil 304-1 has a second end 304-5 bent 90 degrees and extending on the surface of the magnetic core, and covering a part of the surface. The extended part is also equivalent to extending on the surface of the PCB bottom board 201 and soldered to the PCB bottom board 201. In other words, the first end 304-3 and the second end 304-5 of the coil 304-1 extend along a plane perpendicular to the magnetic core channels 303-1 and 303-2, and the sides of the extended surface also extend on the surfaces of the PCB top board 202 and the PCB bottom board 201. Similarly, the coil 304-2 has a first end 304-4 bent 90 degrees and extending on the surface of the magnetic core, and covering a part of the surface, and the extended part is also equivalent to extending on the surface of the PCB top board 202 and soldered to the PCB top board 202, and has a second end 304-6 bent 90 degrees and extending on the surface of the magnetic core, and covering a part of the surface, and the extended part is also equivalent to extending on the surface of the PCB bottom board 201 and soldered to the PCB bottom board 201. In other words, the first end 304-4 and the second end 304-6 of the coil 304-2 extend along a plane perpendicular to the magnetic core channels 303-1 and 303-2, and the side edges of the extended surface also extend on the surfaces of the PCB top board 202 and the PCB bottom board 201.

In the embodiment of FIG. 3 , the shapes of the first core portion 301 and the second core portion 302 of the magnetic core are not symmetrical, wherein the first core portion 301 has a planar shape, and the second core portion 302 has two grooves, and channels 303-1 and 303-2 are respectively formed by the two grooves of the second core portion 302 and a surface 301-1 of the first core portion 301, as shown in FIG. 3 .

In the embodiment of FIG. 3 , the metal sheets 305-1 and 305-2 have an L shape. The two ends of the metal sheets 305-1 and 305-2 are respectively welded to the PCB top plate 202 and the PCB bottom plate 201. The ends of the metal sheets 305-1 and 305-2 welded to the PCB top plate 202 are bent 90 degrees and extended on the surface of the magnetic core, which is equivalent to extending on the surface of the PCB top plate 202, and are electrically connected to the ground pin of the power device chip 203 through the pad of the PCB top plate 202, thereby reducing the wiring of the PCB top plate 202 and its wiring impedance.

FIG4 shows a three-dimensional exploded view of an inductor assembly 40 according to an embodiment of the present invention. The inductor assembly 40 can be used as the inductor assembly 206 in the power module of FIG2. As shown in FIG4, the inductor assembly 40 includes: a magnetic core, including a first magnetic core portion 401 and a second magnetic core portion 402, wherein the first magnetic core portion 401 and the second magnetic core portion 402 are combined together to form two channels 403-1 and 403-2 at the joint surface of the two; and coils 404-1 and 404-2, passing through the channels 403-1 and 403-2 respectively.

In the embodiment of FIG. 4 , when the inductor assembly 40 is applied to the power module 20 shown in FIG. 2 , the channels 403-1 and 403-2 are perpendicular to the PCB bottom plate 201 and the PCB top plate 202 , that is, the channels 403-1 and 403-2 have a radial direction along the axis “B” shown in FIG. 2 .

In the embodiment of FIG. 4 , the coil 404-1 has a first end 404-3 bent 90 degrees and extending on the surface of the magnetic core, and covering a part of the surface, and the extended part is also equivalent to extending on the surface of the PCB top board 202, and is soldered to the PCB top board 202, and has a second end 404-5 bent 90 degrees and extending on the surface of the magnetic core, and covering a part of the surface, and the extended part is also equivalent to extending on the surface of the PCB bottom board 201, and is soldered to the PCB bottom board 201. In other words, the first end 404-3 and the second end 404-5 of the coil 404-1 extend along a plane perpendicular to the magnetic core channels 403-1 and 403-2, and the extended surface also extends on the surface of the PCB top board 202 and the PCB bottom board 201. Similarly, the coil 404-2 has a first end 404-4 bent 90 degrees and extending on the surface of the magnetic core, and covering a part of the surface, and the extended part is also equivalent to extending on the surface of the PCB top board 202 and soldered to the PCB top board 202, and has a second end 404-6 bent 90 degrees and extending on the surface of the magnetic core, and covering a part of the surface, and the extended part is also equivalent to extending on the surface of the PCB bottom board 201 and soldered to the PCB bottom board 201. In other words, the first end 404-4 and the second end 404-6 of the coil 404-2 extend along a plane perpendicular to the magnetic core channels 403-1 and 403-2, and the extension surface also extends on the surface of the PCB top board 202 and the PCB bottom board 201.

In some embodiments, the second end 404-5 of the coil 404-1 and the second end 404-6 of the coil 404-2 may not be bent. Whether the second end of the coil is bent, the direction of the bend and the shape of the extended surface, etc., depends on the position of the corresponding pad on the PCB bottom plate 201, or if there is no PCB bottom plate 202, it depends on the position of the corresponding pad on the main board where the power module 20 is located.

In the embodiment of FIG. 4 , the shapes of the first core portion 401 and the second core portion 402 of the magnetic core are not symmetrical, wherein the first core portion 401 has a planar shape, the second core portion 402 has two grooves, and channels 403-1 and 403-2 are respectively formed by the two grooves of the second core portion 402 and a surface 401-1 of the first core portion 401.

In the embodiment of FIG. 4 , the metal sheets 405-1 and 405-2 have a C-shape. The two ends of the metal sheets 405-1 and 405-2 are respectively welded to the PCB top plate 202 and the PCB bottom plate 201. One end of the metal sheets 405-1 and 405-2 welded to the PCB bottom plate 201 is bent 90 degrees and extended on the surface of the magnetic core, which is equivalent to extending on the surface of the PCB bottom plate 201. The extended surface is welded to the corresponding pad of the PCB bottom plate 201, thereby reducing the routing of the PCB bottom plate 201 and its routing impedance. Similarly, the metal sheets 405-1 and 405-2 are welded to one end of the PCB top plate 202 and bent 90 degrees to extend on the surface of the magnetic core, which is equivalent to extending on the surface of the PCB top plate 202, and are electrically connected to the ground pin of the power device chip 203 through the solder pad of the PCB top plate 202, thereby reducing the routing of the PCB top plate 202 and its routing impedance.

FIG5 shows a three-dimensional exploded view of an inductor assembly 50 according to an embodiment of the present invention. The inductor assembly 50 can be used as the inductor assembly 206 in the power module of FIG2. As shown in FIG5, the inductor assembly 50 includes: a magnetic core, including a first magnetic core portion 501 and a second magnetic core portion 502, wherein the first magnetic core portion 501 and the second magnetic core portion 502 are combined together to form two channels 503-1 and 503-2 at the joint surface of the first magnetic core portion 501 and the second magnetic core portion 502; and coils 504-1 and 504-2, passing through the channels 503-1 and 503-2 respectively.

In the embodiment of FIG. 5 , when the inductor assembly 50 is applied to the power module 20 shown in FIG. 2 , the channels 503 - 1 and 503 - 2 are perpendicular to the PCB bottom plate 201 and the PCB top plate 202 , that is, the channels 503 - 1 and 503 - 2 have a radial direction along the axis “B” shown in FIG. 2 .

In the embodiment of FIG. 5 , the metal sheet 505 has a C-shape. The two ends of the metal sheet 505 are respectively welded to the PCB top plate 202 and the PCB bottom plate 201. One end of the metal sheet 505 welded to the PCB bottom plate 201 is bent 90 degrees and extended on the surface of the magnetic core, which is equivalent to extending on the surface of the PCB bottom plate 201. The extended surface is welded to the corresponding pad of the PCB bottom plate 201, thereby reducing the routing of the PCB bottom plate 201 and its routing impedance. Similarly, one end of the metal sheet 505 soldered to the PCB top board 202 is bent 90 degrees and extended on the surface of the magnetic core, which is equivalent to extending on the surface of the PCB top board 202, and is electrically connected to the ground pin of the power device chip 203 through the solder pad of the PCB top board 202, thereby reducing the wiring of the PCB top board 202 and its wiring impedance. In the embodiment of FIG. 5, the part of the metal sheet 505 that wraps the side surface of the magnetic core is extended as much as possible to increase the area to reduce its own impedance.

Compared with the inductor assembly 40 shown in FIG4 , the inductor assembly 50 in FIG5 has a single metal sheet 505 for electrically connecting the ground pin of the power device chip 203 to the PCB bottom plate 201. Compared with FIG4 , FIG5 lacks a metal sheet, so the metal sheet 505 and the coils 504-1 and 504-2 have a larger extensible area on the upper and lower surfaces of the magnetic core, thereby making the distribution of the ground pin of the power device chip 203 more flexible.

In FIG. 5 , the first magnetic core portion 501 and the second magnetic core portion 502 of the magnetic core are similar to the magnetic core structure in FIG. 4 , and for the sake of brevity, they are not further described here.

FIG6 shows a schematic diagram of the structure of a magnetic core 60 according to an embodiment of the present invention. In FIG6, the magnetic core 60 includes a first magnetic core portion 601 and a second magnetic core portion 602 of symmetrical shapes, wherein each magnetic core portion has two grooves. When the magnetic core 60 is used in the inductor assembly of the embodiments of FIG3-FIG5, the grooves of the two magnetic core portions overlap to form two channels for the coil to pass through.

FIG. 7 shows a schematic diagram of the structure of a magnetic core 70 according to an embodiment of the present invention. In FIG. 7 , the magnetic core 70 includes a first magnetic core portion 701, a second magnetic core portion 702, and a third magnetic core portion 703-1 to 703-3. The first magnetic core portion 701, the second magnetic core portion 702, and the third magnetic core portions 703-1 and 703-2 construct a first channel 704-1. The first magnetic core portion 701, the second magnetic core portion 702, and the third magnetic core portions 703-2 and 703-3 construct a second channel 704-2. As can be seen from FIG. 7 , when there are more third magnetic core portions, more magnetic core channels can be constructed. The first magnetic core portion 701, the second magnetic core portion 702, and the third magnetic core portions 703-1 to 703-3 can be made of different materials, thereby providing a more flexible and adjustable inductance-current curve.

In some embodiments of the present invention, the core parts of the magnetic core can be made of the same material but have different shapes, or made of different materials, such as ferrite, iron powder or other suitable materials, in order to achieve the desired inductance-current characteristic curve, for example, a large inductance value at a small current and a small inductance value at a large current. A large inductance value at a small current can make the system more efficient, while a small inductance value at a large current can make the system transient better.

For the purpose of briefly explaining the principle of the present invention, the embodiments of FIG. 3 to FIG. 5 only show a magnetic core having two channels through which two coils can be passed. A person skilled in the art should know that, according to the needs of the application, the magnetic core can have any number of channels through which any number of coils can be passed, and single or multiple channels are in line with the subject matter of the present invention.

In some embodiments, there may be air gaps between different core parts of the magnetic core to form coupled inductors. In some embodiments, there are no air gaps between the core parts, thereby forming multiple single inductors.

In the present invention, in order to make the surface of the inductor module flat, the coil and metal sheet covering the surface of the magnetic core are embedded in the surface of the magnetic core, as shown in Figures 3 to 5.

FIG8 shows a three-dimensional exploded view of an inductor 80 according to an embodiment of the present invention. The inductor 80 can be used as the inductor 206 in the power module of FIG2. As shown in FIG8, the inductor 80 includes: a magnetic core including a first magnetic core portion 801, a second magnetic core portion 802 and a third magnetic core portion 803, wherein channels 801-1 and 801-2 are formed between the opposite surfaces of the first magnetic core portion 801 and the second magnetic core portion 802, and between the opposite surfaces of the first magnetic core portion 801 and the third magnetic core portion 803, respectively; and coils 804-1 and 804-2 pass through the channels 801-1 and 801-2, respectively.

In the embodiment of FIG. 8 , when the inductor 80 is applied to the power module 20 shown in FIG. 2 , the channels 801-1 and 801-2 are perpendicular to the PCB bottom plate 201 and the PCB top plate 202 , that is, the channels 801-1 and 801-2 have a radial direction along the axis “B” shown in FIG. 2 .

In the embodiment of FIG. 8 , the coil 804-1 has a first end 804-3 and a second end 804-5. The first end 804-3 is bent 90 degrees, extends on the upper surface of the magnetic core and covers a portion of the upper surface of the magnetic core, and the second end 804-5 is flush with the lower surface of the magnetic core. In other words, the first end 804-3 extends on a surface perpendicular to the channels 801-1 and 801-2, and the extended surface is welded to the PCB top plate 202. The second end 804-5 is not extended and is directly welded to the PCB bottom plate 201. Similarly, the coil 804-2 has a first end 804-4 and a second end 804-6. The first end 804-4 is bent 90 degrees, extends toward the upper surface of the magnetic core and covers a portion of the upper surface of the magnetic core, and the second end 804-6 is flush with the lower surface of the magnetic core. That is, the first end 804-4 extends on a surface perpendicular to the channels 801-1 and 801-2, and the extended surface is soldered to the PCB top plate 202. The second end 804-6 is not extended and is directly soldered to the PCB bottom plate 201.

In some embodiments, the second end 804-5 of the coil 804-1 and the second end 804-6 of the coil 804-2 can also be bent 90 degrees and extended on the lower surface of the magnetic core, like the first end 804-3 of the coil 804-1 and the first end 804-4 of the coil 804-2. Whether the second end of the coil is bent and extended, and the direction and size of the extension depend on the position of the corresponding pad on the PCB bottom board of the power module. If there is no PCB bottom board, it depends on the position of the corresponding pad on the main board where the power module is located.

In the embodiment of FIG8 , the magnetic core includes a first magnetic core portion 801, a second magnetic core portion 802, and a third magnetic core portion 803. Viewed from top to bottom, the first magnetic core portion 801 is in an "H" shape, and the two grooves are located on two opposite sides of the first magnetic core portion 801. The second magnetic core portion 802 and the third magnetic core portion 803 are in a long strip shape, and are respectively embedded in the two grooves, but are not completely fitted, leaving part of the groove space to form channels 801-1 and 801-2. In other embodiments, the first magnetic core portion 801 may also have other symmetrical structures in which the grooves are distributed on two opposite sides.

In order to make the inductance-current characteristic curve more flexible and adjustable, the first magnetic core part 801, the second magnetic core part 802 and the third magnetic core part 803 can be made of different materials. For example, the first magnetic core part 801 can be ferrite, and the second magnetic core part 802 and the third magnetic core part 803 can be iron powder. It should be understood that a person skilled in the art can select different magnetic core materials according to the inductance-current characteristic curve required by the application.

In the embodiment of FIG8 , the metal sheets 805-1, 805-2 and 806 are in a “C” shape when viewed from the side. The metal sheets 805-1, 805-2 and 806 are used to weld the PCB top plate 202 and the PCB bottom plate 201. As shown in FIG8 , both ends of the metal sheets 805-1, 805-2 and 806 are bent 90 degrees and extended along the PCB top plate 202 and the PCB bottom plate 201. The extended surface is welded to the corresponding pads of the PCB top plate 202 and the PCB bottom plate 201, thereby saving the internal wiring of the PCB board and minimizing the high impedance caused by the internal wiring of the PCB board. In one embodiment, the metal sheets 805-1 and 805-2 are used to electrically connect the ground pins of the power device chip 203 to the PCB bottom plate 201 or the main board through the PCB top plate 202. The metal sheet 806 is used to electrically connect the power pins of the power device chip 203 (the pins corresponding to the ports for receiving the input voltage Vin shown in FIG. 1) to the PCB bottom plate 201 or the main board through the PCB top plate 202.

FIG9 shows a three-dimensional exploded view of an inductor 90 according to an embodiment of the present invention. The inductor 90 can be used as the inductor 206 in the power module of FIG2. As shown in FIG9, the inductor 90 includes: a magnetic core 901 having a symmetrical structure in a top view, two channels 901-1 and 901-2 passing through the magnetic core 901 from top to bottom and symmetrically distributed on both sides of the center axis "D" in the top view; and coils 902-1 and 902-2 passing through the channels 901-1 and 901-2, respectively.

In the embodiment of FIG. 9 , when the inductor 90 is applied to the power module 20 shown in FIG. 2 , the channels 901-1 and 901-2 are perpendicular to the PCB bottom plate 201 and the PCB top plate 202 , that is, the channels 901-1 and 901-2 have a radial direction along the axis “B” shown in FIG. 2 .

In the embodiment of FIG. 9 , the coil 902-1 has a first end 902-3 and a second end 902-5. The first end 902-3 is bent 90 degrees, extending toward the upper surface of the magnetic core and covering a portion of the upper surface of the magnetic core, and the second end 902-5 is flush with the lower surface of the magnetic core. In other words, the first end 902-3 is extended on a surface perpendicular to the channels 901-1 and 901-2, and the extended surface is welded to the PCB top plate 202. The second end 902-5 is not extended, but is directly welded to the PCB bottom plate 201. Similarly, the coil 902-2 has a first end 902-4 and a second end 902-6. The first end 902-4 is bent 90 degrees, extending toward the upper surface of the magnetic core and covering a portion of the upper surface of the magnetic core, and the second end 902-6 is flush with the lower surface of the magnetic core. That is, the first end 902-4 extends on a surface perpendicular to the channels 901-1 and 901-2, and the extended surface is soldered to the PCB top plate 202. The second end 902-6 is not extended and is directly soldered to the PCB bottom plate 201.

In some embodiments, the second end 902-5 of the coil 902-1 and the second end 902-6 of the coil 902-2 can also be bent 90 degrees and extended on the lower surface of the magnetic core, like the first end 902-3 of the coil 902-1 and the first end 902-4 of the coil 902-2. Whether the second end of the coil is bent and extended, and the direction and size of the extension depend on the position of the corresponding pad on the PCB bottom board of the power module. If there is no PCB bottom board, it depends on the position of the corresponding pad on the main board where the power module is located.

In the embodiment of FIG. 9 , the metal sheets 903-1, 903-2 and 904 are in a “C” shape when viewed from the side. The metal sheets 903-1, 903-2 and 904 are used to weld the PCB top plate 202 and the PCB bottom plate 201. As shown in FIG. 9 , both ends of the metal sheets 903-1, 903-2 and 904 are bent 90 degrees and extended along the PCB top plate 202 and the PCB bottom plate 201. The extended surface is welded to the corresponding pads of the PCB top plate 202 and the PCB bottom plate 201, thereby saving the internal wiring of the PCB board and minimizing the high impedance caused by the internal wiring of the PCB board. In one embodiment, metal sheets 903-1 and 903-2 are used to electrically connect the ground pins of the power device chip 203 to the PCB bottom plate 201 or the main board through the PCB top plate 202. Metal sheet 904 is used to electrically connect the power pins of the power device chip 203 (the pins for receiving the input voltage Vin shown in FIG. 1 ) to the PCB bottom plate 201 or the main board through the PCB top plate 202.

FIG10 shows a three-dimensional exploded view of an inductor 100 according to an embodiment of the present invention. The inductor 100 can be used as the inductor 206 in the power module of FIG2. As shown in FIG10, the inductor 100 includes: a magnetic core 1001 having a symmetrical structure in a top view, two channels 1001-1 and 1001-2 passing through the magnetic core 1001 from top to bottom and symmetrically distributed on both sides of the center axis "D" in the top view, wherein two air gaps 1001-3 and 1001-4 are distributed on the outer arms 1001-5 and 1001-6 of the magnetic core along the channels 1001-1 and 1001-2, respectively; and coils 1002-1 and 1002-2 passing through the channels 1001-1 and 1001-2, respectively.

The inductor 100 in FIG10 is similar to the inductor 90 in FIG9 , and will not be described in detail here. The difference between the two is that the magnetic core 1001 in FIG10 has an air gap, so the magnetic resistance is greater than that of the magnetic core 901 in FIG9 .

In various embodiments of the present invention, the magnetic core or various components of the magnetic core finally form a cubic structure. Those skilled in the art should know that any magnetic core with a symmetrical top view can be used in the present invention, such as a cylinder, a hexagonal prism, etc.

In some embodiments, the metal layer covering the outer surface of the inductor in FIGS. 8-10 may have other shapes, such as L-shaped, that is, the first end of the metal layer is bent and extended and soldered to the PCB top board, such as the metal layers 305-1 and 305-2 shown in FIG3, and the second end is not bent. In some embodiments, the L-shaped metal layer may also be bent and extended at the second end and soldered to the PCB bottom board or main board, that is, the metal layers 305-1 and 305-2 shown in FIG3 are inverted, and the first end is not bent.

In the present invention, in order to make the outer surface of the inductor flat, the portion of the coil exposed on the outer surface of the inductor and the metal layer covering the outer surface of the inductor are embedded into the outer surface of the inductor, as shown in FIGS. 3-5 and 8-10.

In summary, many changes and variations of the present invention are obviously feasible. Therefore, it should be understood that within the scope defined by the patent application, the present invention may not be implemented according to the above specific description. It should also be understood that the above disclosure only relates to some preferred embodiments of the present invention, and changes may be made to the present invention without departing from the spirit and scope defined by the patent application of the present invention. When only one preferred embodiment is disclosed, it is not difficult for ordinary technicians in this field to think of its variations and put them into practice without departing from the spirit and scope defined by the patent application of the present invention.

10: Multiphase power converter 101: Controller 102: Power stage 103: Power device 104: Load M1, M2: Power switch DR1: Driver L1, 80, 90, 100: Inductor 20: Power module 201: PCB bottom plate 202: PCB top plate 203: Power device chip 204: Connector 205: Metal pillar 206: Inductor assembly 207, 304-1, 304-2, 404-1, 404-2, 504-1, 504-2, 804-1, 804-2, 902-1, 902-2, 1002-1, 1002-2: Coil 208: Components 209,305-1,305-2,405-1,405-2,505,805-1,805-2,806,902-1,903-2,904,1003-1,1003-2:Metal sheet 30,40,50:Inductor assembly 301,302,401,402,501,502,601,602,701,702,703-1,703-2,703-3,801,802,803:Core part 303-1,303-2,403-1,403-2,503-1,503-2,704-1,704-2,801-1,801-2,901-1,901-2,1001-1,1001-2: Channel 304-3,304-4,304-5,304-6,404-3,404-4,404-5,404-6,504-3,504-4,504-5,504-6,804-3,804-4,804-5,804-6,902-3,902-4,902-5,902-6,1002-3,1002-4,1002-5,1002-6: Endpoint 301-1,401-1,501-1: Surface 60,70,901,1001: Magnetic core 1001-5,1001-6: Magnetic core outer arm 1001-3,1001-4: Air gap 105-1~105-N: Control signal

In order to better understand the present invention, the present disclosure will be described in detail according to the following drawings. The same components have the same drawing numbers. The following drawings are for illustration only and may only show part of the device and may not be drawn to actual scale. [Figure 1] shows a circuit diagram of an existing multi-phase power converter 10; [Figure 2] shows a schematic diagram of a power module 20 with a sandwich structure that integrates a two-phase power converter according to an embodiment of the present invention; [Figure 3] shows a three-dimensional exploded view of an inductor group 30 according to an embodiment of the present invention; [Figure 4] shows a three-dimensional exploded view of an inductor group 40 according to an embodiment of the present invention; [Figure 5] shows a three-dimensional exploded view of an inductor group 50 according to an embodiment of the present invention; [Figure 6] shows a structural schematic diagram of a magnetic core 60 according to an embodiment of the present invention; [Figure 7] shows a structural schematic diagram of a magnetic core 70 according to an embodiment of the present invention; [Figure 8] shows a three-dimensional exploded view of an inductor group 80 according to an embodiment of the present invention; [Figure 9] shows a three-dimensional exploded view of an inductor assembly 90 according to an embodiment of the present invention; [Figure 10] shows a three-dimensional exploded view of an inductor assembly 100 according to an embodiment of the present invention.

80: Inductor

801,802,803: Magnetic core part

801-1,801-2: Channel

804-1,804-2: Coil

804-3,804-4,804-5,804-6: Endpoints

805-1,805-2,806:Metal sheet

Claims (31)

An inductor group for a power module includes: a magnetic core having a symmetrical structure in top view, and having two channels penetrating the magnetic core from top to bottom from the upper surface of the magnetic core to the lower surface of the magnetic core, and distributed on both sides of a central axis of a top view surface of the magnetic core, and the upper surface and the lower surface of the magnetic core are parallel to a PCB (printed circuit board) top board; and a first coil and a second coil, wherein each coil has a first end, a second end and a connecting portion, wherein the connecting portion of each coil passes through the two channels of the magnetic core respectively, and at least one of the first end and the second end is bent and extends on a plane perpendicular to a length of the coil. The inductor assembly as described in claim 1, wherein the first end of the first coil and the first end of the second coil are bent and extend in opposite directions on the upper surface of the magnetic core. The inductor assembly as described in claim 1, wherein the second end of the first coil and the second end of the second coil are bent and extend in opposite directions on the lower surface of the magnetic core. The inductor assembly as described in claim 1, wherein the first coil and the second coil are both C-shaped, the C-shaped opening of the first coil faces a first side of the magnetic core, the C-shaped opening of the second coil faces a second side of the magnetic core, and the first side and the second side are parallel to each other. The inductor assembly as described in claim 1, wherein the magnetic core includes at least two magnetic core parts, and two channels are formed inside the magnetic core to respectively accommodate the connecting portion of the first coil and the connecting portion of the second coil. The inductor assembly as described in claim 1, wherein the magnetic core includes a first magnetic core portion, a second magnetic core portion and a third magnetic core portion, the first magnetic core portion has two grooves distributed on opposite sides, the second magnetic core portion and the third magnetic core portion are respectively embedded in the two grooves, and a portion of the groove space is reserved to form the two channels, wherein the two coils pass through the two channels respectively. The inductor assembly as described in claim 1, wherein the magnetic core comprises: a first magnetic core portion, which is "H"-shaped in top view and has two grooves respectively distributed on two opposite sides; a second magnetic core portion; and a third magnetic core portion; wherein the second magnetic core portion is located on one of the groove sides of the first magnetic core portion and forms a channel together with the one groove, and the third magnetic core portion is located on another groove side of the first magnetic core portion and forms another channel together with the other groove, wherein the first coil and the second coil pass through the two channels respectively. The inductor assembly as described in claim 1, wherein the magnetic core comprises: a first magnetic core portion, which is "H"-shaped when viewed from the top, and has two grooves respectively distributed on two opposite sides; a second magnetic core portion; and a third magnetic core portion; wherein the second magnetic core portion and the third magnetic core portion are respectively embedded in the two grooves, and a portion of the groove space is reserved to form the two channels, wherein the two coils respectively pass through the two channels. An inductor group as described in any one of claim 6-8, wherein the second magnetic core part and the third magnetic core part are made of the same material, and the first magnetic core part is made of a different material from the second magnetic core part and the third magnetic core part. An inductor assembly as described in claim 1, wherein the magnetic core is an integral single module. An inductor assembly as described in claim 10, wherein the magnetic core includes two air gaps, which are respectively distributed along the two channels and pass through an outer arm of the magnetic core next to the channels. The inductor assembly as described in claim 1 further includes a plurality of metal sheets wrapping a portion of the surface of the magnetic core of the inductor assembly, wherein at least one of the metal sheets is electrically connected to a power pin of a power device chip, and the rest of the metal sheets are electrically connected to a ground pin of the power device chip. The inductor assembly as described in claim 12, wherein the metal sheets are "C" shaped when viewed from the side, with a first end bent and extending on the upper surface of the magnetic core, and a second end bent and extending on the lower surface of the magnetic core. The inductor assembly as described in claim 12, wherein the metal sheets are "L" shaped when viewed from the side, with one end bent and extending on the upper surface of the magnetic core. A power module, comprising an inductor group as described in any one of claim items 1-8, 10-12, and further comprising: a PCB top board located on the inductor group; and two power device chips located on the PCB top board, wherein the two power device chips each have at least one pin electrically connected to the corresponding coil through the PCB top board. The power module as described in claim 15 further comprises: a PCB bottom plate, located under the inductor group; and a connector, connecting the PCB top plate and the PCB bottom plate, wherein the connector has a plurality of metal pillars, which are respectively welded to a corresponding pad of the PCB top plate and the PCB bottom plate. A power module includes: a PCB (printed circuit board) bottom plate; an inductor group located on the PCB bottom plate, including: a magnetic core having a symmetrical structure in top view, and having two channels penetrating the magnetic core from top to bottom from the upper surface of the magnetic core to the lower surface of the magnetic core, and distributed on both sides of a central axis of a top view surface of the magnetic core, and the upper surface and the lower surface of the magnetic core are parallel to the PCB bottom plate; and a first coil and a second coil, wherein each coil has a first end, a second end and a connecting portion, wherein the connecting portion of each coil passes through the two channels of the magnetic core respectively, and at least one of the first end and the second end is bent. After folding, it extends on a plane perpendicular to a length of the coil; a PCB top plate, located on the inductor group; a connector, used to connect the PCB top plate and the PCB bottom plate, wherein the connector has a plurality of metal pillars, which are respectively soldered to corresponding pads of the PCB top plate and the PCB bottom plate; and a first power device chip and a second power device chip, located on the PCB top plate, wherein the first power device chip has a first pin electrically connected to the first coil through the PCB top plate, and the second power device chip has a second pin electrically connected to the second coil through the PCB top plate. The power module as described in claim 17 also includes a plurality of separation devices located on the PCB top plate. A power module as described in claim 17, wherein the first end of the first coil and the first end of the second coil are bent and extend in opposite directions on the upper surface of the magnetic core. A power module as described in claim 17, wherein the second end of the first coil and the second end of the second coil are bent and extend in opposite directions on the lower surface of the magnetic core. A power module as described in claim 17, wherein the first coil and the second coil are both C-shaped, the C-shaped opening of the first coil faces a first side of the magnetic core, the C-shaped opening of the second coil faces a second side of the magnetic core, and the first side and the second side are parallel to each other. A power module as described in claim 17, wherein the magnetic core includes at least two magnetic core parts, and two channels are formed inside the magnetic core to respectively accommodate the connecting portion of the first coil and the connecting portion of the second coil. A power module as described in claim 17, wherein the magnetic core includes a first magnetic core portion, a second magnetic core portion and a third magnetic core portion, the first magnetic core portion has two grooves distributed on opposite sides, the second magnetic core portion and the third magnetic core portion are respectively embedded in the two grooves, and a portion of the groove space is reserved to form the two channels, wherein the two coils pass through the two channels respectively. The power module as claimed in claim 17, wherein the magnetic core comprises: a first magnetic core portion, which is "H"-shaped in top view and has two grooves respectively distributed on two opposite sides; a second magnetic core portion; and a third magnetic core portion; wherein the second magnetic core portion is located on one of the grooves of the first magnetic core portion and forms a channel together with the one groove, and the third magnetic core portion is located on another groove side of the first magnetic core portion and forms another channel together with the other groove, wherein the first coil and the second coil pass through the two channels respectively. A power module as described in claim 17, wherein the magnetic core comprises: a first magnetic core portion, which is "H"-shaped when viewed from the top, and has two grooves respectively distributed on two opposite sides; a second magnetic core portion; and a third magnetic core portion; wherein the second magnetic core portion and the third magnetic core portion are respectively embedded in the two grooves, and a portion of the groove space is reserved to form the two channels, wherein the two coils respectively pass through the two channels. A power module as described in any one of claim items 23-25, wherein the second magnetic core portion and the third magnetic core portion are made of the same material, and the first magnetic core portion is made of a different material from the second magnetic core portion and the third magnetic core portion. A power module as described in claim 17, wherein the magnetic core is an integral single module. A power module as described in claim 27, wherein the magnetic core includes two air gaps, which are respectively distributed along the two channels and pass through an outer arm of the magnetic core next to the channels. The power module as described in claim 17 further includes a plurality of metal sheets wrapping a portion of the surface of the magnetic core of the inductor assembly, wherein at least one of the metal sheets is electrically connected to a power pin of a power device chip, and the remaining metal sheets are electrically connected to a ground pin of the power device chip. A power module as described in claim 29, wherein the metal sheets are "C"-shaped when viewed from the side, with a first end bent and extending on the upper surface of the magnetic core, and a second end bent and extending on the lower surface of the magnetic core. A power module as described in claim 29, wherein the metal sheets are "L"-shaped when viewed from the side, with one end bent and extending on the upper surface of the magnetic core.

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