阅读说明：本技术 一种基于功能复用磁件的氮化镓集成功率模块 (Gallium nitride integrated power module based on function multiplexing magnetic part ) 是由 王来利 于龙洋 王晨雅 慕伟 杨成子 崔洪昌 于 2021-08-30 设计创作，主要内容包括：本发明公开了一种基于功能复用磁件的氮化镓集成功率模块,包括PCB板及多功能三维集成磁芯器件,其中,PCB板上集成有氮化镓器件、驱动电路及解耦电容,多功能三维集成磁芯器件包括散热板,散热板上设置有四个通孔,其中,各通孔内均设置有磁芯,其中,各磁芯上均设置有绕组,绕组与PCB板相连接,散热板位于PCB板的下方,该模块的冷却能力优异。(The invention discloses a gallium nitride integrated power module based on a function multiplexing magnetic part, which comprises a PCB (printed Circuit Board) and a multifunctional three-dimensional integrated magnetic core device, wherein the PCB is integrated with the gallium nitride device, a driving circuit and a decoupling capacitor, the multifunctional three-dimensional integrated magnetic core device comprises a heat dissipation plate, the heat dissipation plate is provided with four through holes, magnetic cores are arranged in the through holes, windings are arranged on the magnetic cores, the windings are connected with the PCB, the heat dissipation plate is positioned below the PCB, and the module is excellent in cooling capacity.)

1. The utility model provides a gallium nitride integrated power module based on function multiplexing magnetism spare, a serial communication port, including PCB board (1) and multi-functional three-dimensional integrated magnetic core device, wherein, the integration has the gallium nitride device on PCB board (1), drive circuit and decoupling zero electric capacity, multi-functional three-dimensional integrated magnetic core device includes heating panel (2), be provided with four through-holes on heating panel (2), wherein, all be provided with magnetic core (4) in each through-hole, wherein, all be provided with winding (3) on each magnetic core (4), winding (3) are connected with PCB board (1), heating panel (2) are located the below of PCB board (1).

2. The gan integrated power module based on functional multiplexing magnetics of claim 1, characterized in that the winding (3) is a copper foil.

3. The gan integrated power module based on functional multiplexing magnetic part according to claim 1, characterized in that the PCB board (1) is provided with slots for connecting the windings (3).

4. The gan integrated power module based on functional multiplexing magnetic part according to claim 1, wherein the bottom of the PCB board (1) is in contact with the upper surface of the heat sink plate (2).

5. The gan integrated power module based on functional multiplexing magnetic part of claim 1, wherein the heat sink plate (2) is made of an alloy material.

6. The integrated power module of gallium nitride based on functional multiplexing magnetic part of claim 5, wherein the alloy material is model number NPX.

Technical Field

The invention relates to a gallium nitride integrated power module, in particular to a gallium nitride integrated power module based on a functional multiplexing magnetic piece.

Background

POL converters based on gallium nitride devices face a number of challenges. One of the biggest challenges is the reliability of gan devices in industrial applications. Gallium nitride devices have lower switching losses and smaller packages than silicon devices, but the performance of gallium nitride devices is more fragile. Due to the increased switching speed, gallium nitride devices are very sensitive to parasitic inductance caused by the PCB layout. The turn-on voltage of gallium nitride devices manufactured by the company EPC is 5V, and the breakdown voltage is only 6V. Thus, the 1V margin indicates that the parasitic inductance of the gate loop must be reduced very low, which allows overvoltage less than 1V or even less. Due to LGA or BGA packaging, the parasitic inductance in EPC gallium nitride devices is very small, even less than 1 nH. Therefore, parasitic inductance caused by the external PCB layout is a major impact on the gallium nitride device. Reducing parasitic inductance in PCB copper lines is a necessary approach to improve reliable operation of gallium nitride devices. Many methods have been proposed to reduce parasitic inductance. Active integration is a very effective solution to improve the reliability of gallium nitride devices. The concept is that the driving circuit, the gan bare die and the decoupling capacitor can be integrated into the PCB board 1. The power module based on gallium nitride adopts an active integration technology to integrate a half-bridge circuit, so that parasitic induction in a power loop and a grid loop can be minimized, and further, the power density is improved. Meanwhile, the GaN-based power module may be extended to N half-bridge circuits according to the output current level of the POL converter.

The 3D integrated magnetic core technology can effectively utilize the whole space based on the gallium nitride power module, reduce the space waste caused by the plane magnetic component and increase the power density. Low temperature co-fired ceramic (LTCC) technology is used to fabricate the three-dimensional integrated inductor of the high frequency POL converter. The LTCC inductor is a substrate connected to the bottom of the buck converter. LTCC inductance is non-linear and decreases rapidly with increasing output current. The multiphase LTCC inductance is used in the multiphase converter bottom and its inductance value is very low (<15nH), which is suitable for very high frequency converters. In summary, LTCC inductors have low inductance values and nonlinear characteristics. The multi-conductivity LTCC inductor is designed by utilizing the characteristics of the LTCC inductor, the inductance value is large under light load, the inductance value is small under heavy load, and the transient performance under heavy load and the efficiency under light load are improved. The two-phase reverse coupling inductor adopting the LTCC technology is designed and applied to a two-phase reverse coupling inverter with excellent performance, however, the cooling capacity of the device in the prior art is poor.

Disclosure of Invention

The object of the present invention is to overcome the drawbacks of the prior art described above and to provide a gallium nitride integrated power module based on a functional multiplexing magnet, which is excellent in cooling capacity.

In order to achieve the above purpose, the gallium nitride integrated power module based on the functional multiplexing magnetic component comprises a PCB and a multifunctional three-dimensional integrated magnetic core device, wherein the PCB is integrated with the gallium nitride device, a driving circuit and a decoupling capacitor, the multifunctional three-dimensional integrated magnetic core device comprises a heat dissipation plate, the heat dissipation plate is provided with four through holes, magnetic cores are arranged in the through holes, windings are arranged on the magnetic cores, the windings are connected with the PCB, and the heat dissipation plate is located below the PCB.

The winding is copper foil.

And the PCB board is provided with a slot for connecting the winding.

The bottom of the PCB is in contact with the upper surface of the heat dissipation plate.

The heat dissipation plate is made of alloy material.

The model of the alloy material is NPX.

The invention has the following beneficial effects:

when the gallium nitride integrated power module based on the functional multiplexing magnetic part is specifically operated, a gallium nitride device, a driving circuit and a decoupling capacitor are integrated on a PCB, the multifunctional three-dimensional integrated magnetic core device comprises a heat dissipation plate, four through holes are formed in the heat dissipation plate, a magnetic core and a winding are installed in the through holes, the cooling capacity of the whole module is improved through the heat dissipation plate, and the gallium nitride integrated power module based on the functional multiplexing magnetic part is simple in structure, convenient to operate and extremely high in practicability.

Drawings

FIG. 1 is a schematic diagram of the main parasitic inductances in a half-bridge circuit; (ii) a

FIG. 2 is a topology diagram of a four-phase buck converter;

FIG. 3 is an active integration diagram in an integrated power mode;

FIG. 4a is a top level view of the power return path of each half-bridge circuit;

FIG. 4b is a bottom view of the power return path of each half-bridge circuit;

fig. 5 is a path diagram of each half-bridge circuit;

FIG. 6 is a schematic diagram of a multifunctional three-dimensional integrated core 4 device;

FIG. 7 is a schematic structural view of the present invention;

FIG. 8 is a schematic diagram of a multifunctional three-dimensional integrated core device based on an alloy material and a ferrite material;

FIG. 9a is a schematic diagram of a gallium nitride based power module;

FIG. 9b is a schematic of a magnetic composition based on a ferrite material;

FIG. 9c is a schematic representation of the magnetic composition based on the alloy material;

FIG. 9d is a schematic view of the entire prototype;

FIG. 10 is a graph of the measured efficiency of a four-phase POL converter using ferrite and alloy materials for the magnetic element;

FIG. 11a is a graph of the thermal performance of a ferrite material based magnetic composition at full load;

FIG. 11b is a graph of thermal performance at full load based on the magnetic composition of the alloy material.

Wherein, 1 is a PCB, 2 is a heat dissipation plate, 3 is a winding, and 4 is a magnetic core.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments, and are not intended to limit the scope of the present disclosure. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

There is shown in the drawings a schematic block diagram of a disclosed embodiment in accordance with the invention. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, according to actual needs.

Compared with a silicon device, the switching speed is higher, and the gallium nitride device is sensitive to parasitic inductance, so that the PCB layout of the gallium nitride device is very compact, the parasitic inductor in PCB copper traces is reduced as much as possible, and the stable operation of the gallium nitride device is influenced.

The parasitic inductance of the PCB copper trace is divided into a power loop parasitic inductance and a gate loop parasitic inductance, and the distribution of the parasitic inductance is shown in fig. 1 by taking a half bridge as an example.

When the gallium nitride device is turned on or off, the drain voltage on the gallium nitride device oscillates due to the power loop inductance, and the oscillation is more severe the larger the power loop inductance. The gate loop inductance may cause a higher gate-source voltage peak, which may seriously affect the lifetime of the gan device. The maximum gate source voltage of a gallium nitride device from EPC company is only 6V, but the gate source voltage in normal operation is 5V. There are only 1V edges and minimizing gate loop inductance is critical for gallium nitride devices. The compact layout can effectively reduce the power loop and gate loop inductance of the PCB copper lines. Therefore, the power module based on the gallium arsenide is designed through active integration, and the power module consists of a half-bridge drive, a gallium nitride device and a decoupling capacitor.

The power module can minimize parasitic inductance of the power loop and the gate loop, and a schematic diagram of a four-phase interleaved-pole converter is shown in fig. 2, taking a four-phase converter as an example.

The invention provides an integrated power module based on gallium arsenide, which comprises an active power module and a passive power module, wherein the active integration of the power module is shown in figure 3.

The gallium nitride device, the driving circuit and the decoupling capacitor may be integrated into the PCB board 1. Thus, in integrated gallium nitride-based power modules, parasitic inductance, including power loop and gate loop inductance, may be minimized. The power loop inductance depends on the loop area, and the larger the loop area, the larger the power loop parasitic inductance. The PCB layout of the power supply loop has horizontal and vertical structures. Since the current is mainly concentrated on the adjacent upper and lower surfaces, the effective area for the high frequency current to flow is much larger than that of the lateral structure, thus verifying the vertical structure to minimize the parasitic inductance of the power loop. The power circuit in the power module consists of a top switch, a bottom switch and a decoupling capacitor in a half-bridge circuit. The power supply loop adopts a vertical layout as shown in fig. 4. The current for each half bridge starts with the positive bus decoupling capacitor on the top layer, then flows through the upper and lower switches on the left, and then through the holes into the bottom layer. Finally, the current flows to the negative bus decoupling capacitor on the right, and the "software" annotated part of each half-bridge circuit is slotted so that the winding 3 can be fixed on the power module.

The gate loop parasitic inductance depends on the loop area and the distance between the driver and the gallium nitride power device. Therefore, the distance can be reduced to minimize the parasitic inductance of the gate ring. At the same time, the area where the gate and original path from the driver circuit to the gallium nitride device is formed must be minimized to reduce the parasitic inductance of the gate ring. Fig. 5 is a half-bridge driver circuit that may be used for a gaas based power module, and the gate ring has been marked with white dashed lines.

The present invention provides a new three-dimensional magnetic core structure, as shown in fig. 6, in which the four-phase inductor in a four-phase pole converter is integrated into an integrated magnetic core device by a counter-coupling technique. In addition, the integrated magnetic core device uses an alloy material with high thermal conductivity to dissipate heat for the power module, and thus the multifunctional integrated magnetic device can be used as a four-phase inductor and a heat sink. The multifunctional three-dimensional integrated magnetic core device is referred to as a cooling system inductor.

As can be seen from fig. 6, the windings 3 of the four-phase inductor are wound around respective magnetic cores 4 of the magnetic components.

Based on the above distribution, the schematic diagram of the power module based on three-dimensional integrated gallium nitride of the present invention is shown in fig. 7, wherein the multifunctional three-dimensional integrated magnetic core device is connected to the bottom layer of the power module, the winding 3 is implemented by copper foil, and the winding 3 is welded through the corresponding slot on the power module.

Specifically, the gallium nitride integrated power module based on the functional multiplexing magnetic part comprises a gallium nitride device, a driving circuit, a decoupling capacitor and a multifunctional three-dimensional integrated magnetic core device, wherein the gallium nitride device, the driving circuit and the decoupling capacitor are integrated on a PCB (printed circuit board) 1, the multifunctional three-dimensional integrated magnetic core device comprises a heat dissipation plate 2, four through holes are formed in the heat dissipation plate 2, magnetic cores 4 are arranged in the through holes, windings 3 are arranged on the magnetic cores 4, the windings 3 are copper foils, and slots for connecting the windings 3 are formed in the PCB 1. The bottom of the PCB 1 contacts with the upper surface of the heat dissipation plate 2, and the heat dissipation plate 2 is made of alloy material.

Example one

A multifunctional three-dimensional integrated core device is fabricated using alloy and ferrite materials as shown in fig. 8. The switching frequency of the four-phase POL converter is 1MHz, and therefore the ferrite material is DTT-F4 from Shandongtai electronics, Inc., and the alloy material is NPX from POCO. The ferrite material has a thermal conductivity of 3Wm^-1K^-1The thermal conductivity coefficient of the alloy material is 20Wm^-1K^-1. In addition, due to high saturation density and low permeability, the alloy magnetic composition does not require opening an additional air gap, while the ferrite requires opening an air gap to avoid magnetic saturation. For low-voltage and high-current POL converters, the edge effect caused by opening the air gap is very serious, and the loss is large. Therefore, the loss of the alloy material is lower than that of the ferrite material. Fig. 9a to 9d show experimental prototypes based on 90W, 12V to 1.8V gallium nitride, and table 1 shows specific parameters. Fig. 9a is a gan-based power module consisting of four half-bridge circuits, a driving circuit, and a decoupling capacitor. The power density of the gallium nitride based power module is 540W/inch³. It should be noted that the power density can be calculated without using any control circuit, driving power supply circuit, or auxiliary power supply circuit. Fig. 9b shows the use of a ferrite core 4 device fixed to the bottom of the power module, it is clear that the magnetic component requires an open air gap to avoid magnetic saturation; fig. 9c shows that the magnetic component using the alloy material is fixed to the bottom of the power module, and the core 4 device does not need to open an air gap compared to the ferrite material. Fig. 9d shows that the whole experimental prototype consists of a power module and a motherboard, wherein the motherboard comprises an output capacitor and an input bus capacitor.

TABLE 1

Fig. 10 shows the measured efficiency of a four-phase POL converter when the magnetic element uses ferrite and alloy materials, the measured peak efficiency using ferrite material is 87.2% when the output current reaches 32A, and the measured peak efficiency using alloy material is 89.6% when the output current reaches 32A, the measured efficiency using alloy material being higher than the measured efficiency using ferrite material regardless of light, medium or heavy load. Fig. 11 shows the thermal performance at FLIRT630S with the highest temperature concentrated on the first phase half bridge, fig. 11a shows the thermal performance of the ferrite material, the power module has a maximum temperature of 104 ℃ and a phase one synchronous rectifier hot spot of 93.2 ℃. Fig. 11b shows the thermal performance of the alloy material used, which reaches a maximum temperature of 90.1 ℃ observed for the power module, a hot spot of 81.5 ℃ for the primary synchronous rectifier, and 13.9 ℃ lower than the ferrite material.