Power module

Abstract

The utility model discloses a power module comprising a lead frame, the lead frame is provided with a plurality of base islands, a plurality of pins, a first side edge and a second side edge, the first side edge and the second side edge are opposite, and the first side edge and the second side edge extend along a first direction; the high-side transistor, the low-side transistor, the driving circuit and the bootstrap diode are respectively fixed on the plurality of base islands; wherein the high-side transistor and the low-side transistor are respectively arranged on the adjacent base islands close to the second side edge, and the high-side transistor is positioned below the low-side transistor, so that the routing length of the source electrode of the high-side transistor and the output / high-side driving suspension power supply ground end can be reduced; the risk of wire collapse during wire bonding on the packaging structure is reduced, and the packaging yield can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, and more specifically, to a power module. Background Art

[0002] Motor control refers to the precise electrical control and management of electric motors to achieve stable and efficient operation. In existing motor control systems, power modules are used as important components to drive and control motors. Their function is to control the current and voltage of the motors to ensure safe and efficient operation of the motors. In addition, power modules also need to have high reliability, stability and good heat dissipation capabilities to adapt to various working environments and workloads.

[0003] In existing high-voltage three-phase brushless DC motor drive applications, in order to pursue integration, three-phase intelligent power modules (IPMs) are often used for packaging. The three-phase intelligent power module encapsulates multiple power devices such as IGBTs (insulated gate bipolar transistors) or MOSFETs (metal oxide semiconductor field effect transistors) and inverters of multiple driver ICs that drive the power devices in a single package.

[0004] The three-phase intelligent power module has the following main problems: 1. Because of its large size, it cannot be taped and packaged, and automatic placement machines cannot be used for automated production during production, resulting in low production efficiency. 2. A three-phase half-bridge circuit is integrated in the three-phase intelligent power module. If the circuit is damaged during the research and development and production process, the module needs to be replaced as a whole, which is costly. 3. The heat dissipation thermal resistance of the fully plastic-encapsulated module is large, and because the distance between the six power chips of the three-phase half-bridge is too small, the heat generated by the six power chips at the same time cannot be discharged in time when the circuit is working, which easily causes heat accumulation, resulting in more serious heating of the module, thereby increasing the loss of the chip, reducing the chip efficiency, and even causing thermal damage to the chip in severe cases. 4. The internal chip spacing of the three-phase intelligent power module is large, and gold wire and copper wire need to be mixed. The wire bonding process is complex and costly, which also causes low production efficiency and low yield, as well as reliability problems such as high stress and easy delamination caused by the large package volume.

[0005] Therefore, it is necessary to improve the existing technology to reduce the process difficulty, improve the heat dissipation performance and make it suitable for automated production while meeting the requirements of high integration. Utility Model Content

[0006] In view of the above problems, the purpose of the present invention is to provide a power module that solves the above technical problems.

[0007] According to one aspect of the utility model, a power module is provided, comprising: a lead frame, a driving circuit, a low-side transistor and a high-side transistor, the lead frame comprising a plurality of base islands and a plurality of pins, the power module comprising a first side and a second side arranged opposite to each other, and a third side and a fourth side arranged opposite to each other, the first side and the second side extending along a first direction, the third side and the fourth side extending along a second direction, the first side and the third side being perpendicular, the plurality of base islands comprising a first base island, a second base island, a third base island and a fourth base island, the driving circuit being located at the second base island, the low-side transistor being located at the third base island, and the high-side transistor being located at the fourth base island, wherein the high-side transistor and the low-side transistor are close to the second side, the first base island and the low-side transistor are close to the third side, and the driving circuit and the high-side transistor are close to the fourth side.

[0008] Optionally, the first base island and the driving circuit are close to the first side.

[0009] Optionally, the first base island extends a high-side driving suspension power supply terminal toward the first side and the second side respectively.

[0010] Optionally, the high-side drive suspension power supply terminal on the first side is close to the third side, the third base island extends toward the second side, leading out the output / high-side drive suspension power supply ground terminal, and the high-side drive suspension power supply terminal on the second side is adjacent to the output / high-side drive suspension power supply ground terminal.

[0011] Optionally, the high-side drive floating power supply terminal on the second side and the output / high-side drive floating power supply ground terminal are used to connect a bootstrap capacitor.

[0012] Optionally, the output / high-side drive floating power supply ground terminal extends a plurality of pins to the outside of the plastic package body.

[0013] Optionally, the fourth base island extends toward the second side to lead out a DC power supply positive terminal electrically connected to the first end of the high-side transistor, and the DC power supply positive terminal is located on the second side and close to the fourth side.

[0014] Optionally, the DC power supply positive terminal extends a plurality of pins to the outside of the plastic package body.

[0015] Optionally, the high-side driving suspension power supply terminal on the first side and the high-side driving suspension power supply terminal on the second side are electrically connected to the high-side driving suspension power supply terminal of the driving circuit.

[0016] Optionally, two ends of the second base island extend toward the first side respectively to lead out a common ground terminal electrically connected to the common ground terminal of the driving circuit, and one end of the second base island close to the fourth side extends a pin toward the outside of the plastic package.

[0017] Optionally, the lead frame extends toward the first side to lead out a plurality of pins connected to functional pins of the driving circuit.

[0018] Optionally, it also includes: a conductive structure arranged on the lead frame, the conductive structure extending along the first direction, the conductive structure including a first end and a second end, the first end and the second end respectively extending to the two ends of the first side, and the second base island is placed in the space enclosed by the conductive structure and the first side.

[0019] Optionally, the first end of the conductive structure and / or the second end of the conductive structure serves as a negative terminal of a direct current power supply electrically connected to the low-side transistor.

[0020] Optionally, the first end and the second end of the conductive structure both extend pins to the outside of the plastic package of the lead frame to form a first DC power supply negative terminal and a second DC power supply negative terminal, respectively, wherein the first DC power supply negative terminal is located between the high-side floating power supply terminal on the first side and a plurality of pins connected to the functional pins of the drive circuit, and the second DC power supply negative terminal is located on the first side and close to the fourth side.

[0021] Optionally, the DC power supply positive terminal and the second DC power supply negative terminal are both close to the fourth side, and an electrolytic capacitor is connected between the DC power supply positive terminal and the second DC power supply negative terminal.

[0022] Optionally, the second end of the low-side transistor is electrically connected to the conductive structure through a bonding wire.

[0023] Optionally, the driving circuit further includes a reference ground pin, and the reference ground pin of the driving circuit is electrically connected to the conductive structure through a bonding wire.

[0024] Optionally, a bootstrap diode is further included, and the bootstrap diode is located on the first base island, or the bootstrap diode is integrated in the driving circuit.

[0025] Optionally, the high-side transistor and the low-side transistor are one of a MOS device, an RC-IGBT device, an IGBT device and a fast recovery diode.

[0026] Optionally, the high-side transistor and the low-side transistor are MOS devices, and the first end of the transistor, the second end of the transistor and the control end of the transistor are a drain, a source and a gate, respectively.

[0027] Optionally, the high-side transistor and the low-side transistor are IGBT devices, RC-IGBT devices or IGBT devices and fast recovery diodes, and the first end of the transistor, the second end of the transistor and the control end of the transistor are the collector, emitter and base respectively.

[0028] The improved power module provided in the utility model encapsulates the single-phase half-bridge circuit and the drive circuit in one package, so the use of three of the above-mentioned power modules can also realize the function of three-phase motor drive, and compared with the traditional three-phase intelligent power module, the power module of the utility model has a more compact total area, and can realize the flexible layout of the printed circuit board according to the shape of the printed circuit board to reduce the area of ​​the printed circuit board. On the other hand, the power module provided by the utility model is designed based on the standard package that can be mounted, so that the final power module can be realized by braiding packaging, installed by surface mounting process (SMT), and an automatic chip mounter is used for efficient processing when the printed circuit board (PCB) is processed, which can greatly improve production efficiency and processing reliability. In terms of thermal performance, the single-phase power module formed based on the package is not easy to produce heat accumulation effect, which is conducive to heat dissipation and effectively reduces temperature rise. In addition, the pins of the power module of the utility model can be freely arranged, making the PCB layout more flexible. When there is chip damage, only the chip corresponding to one phase needs to be replaced, and the three-phase intelligent power module does not need to be replaced as a whole, which reduces the cost of research and development and production. In addition, single-phase power modules are less prone to delamination and other problems due to their small package size and lower package stress, which can improve production yield and efficiency. Reducing the package volume can also reduce the wire bonding distance between internal chips, which can effectively reduce the occurrence of wire punching, wire collapse and other problems during the packaging process, thereby improving the package yield.

[0029] Furthermore, the power module of the utility model sets the high-side transistor below the low-side transistor in the packaging structure, thereby reducing the wire bonding length of the source electrode of the high-side transistor and the output / high-side drive floating power supply ground terminal, reducing the risk of wire collapse when bonding on the packaging structure, which is conducive to improving the packaging yield rate. In addition, through this arrangement, the DC power supply positive terminal and the DC power supply negative terminal of the packaging structure can also be set on the same side of the lead frame, which is convenient for the PCB wiring of the peripheral electrolytic capacitor.

[0030] Furthermore, the power module extends a high-side drive floating power supply terminal to both the first side and the second side, and the high-side drive floating power supply terminal on the second side extends a plurality of pins outside the plastic package, so that the high-side drive floating power supply terminal and the output / high-side drive floating power supply ground terminal can be arranged adjacent to each other on the same side of the power module, making it convenient to connect a bootstrap capacitor between the high-side drive floating power supply terminal and the output / high-side drive floating power supply ground terminal, thereby optimizing the PCB routing outside the power module.

[0031] Furthermore, the output / high-side drive suspension power supply ground end of the power module of the utility model extends a plurality of pins to the outside of the plastic package, and the DC power supply positive end of the power module extends a plurality of pins to the outside of the plastic package. The heat generated by the high-side transistor and the low-side transistor during operation is transferred to the external positive board card through the plurality of pins, which can effectively reduce the operating temperature of the high-side transistor and the low-side transistor. Through the above-mentioned arrangement, while ensuring heat dissipation, it is also possible to prevent the plastic package from being delaminated during rib cutting, and to avoid the problem of reliability failure caused by the intrusion of water vapor through the gap between the pins and the plastic package. Through the above-mentioned arrangement, a large area of ​​external radiator can be saved on the power module, which can not only reduce production costs, but also help to improve the space utilization rate of the PCB layout.

[0032] Furthermore, the power module of the utility model also includes an "inverted C-type" conductive structure arranged on the lead frame, and the driving circuit is placed in an enclosed space formed by the conductive structure and the first side of the lead frame. By using the conductive structure to separate the power transistor chip whose temperature rises faster during operation from the driving circuit, thermal isolation between the driving circuit and the power chip can be achieved, thereby reducing the temperature rise rate of the driving circuit during operation and improving the working efficiency of the power module.

[0033] Furthermore, the power module of the utility model also sets a functional pin of the reference ground terminal on the driving circuit, and electrically connects the pin to the negative terminal of the DC power supply of the power module through a bonding wire and a conductive structure, so that the driving circuit and the power transistor can share a common ground, thereby avoiding damage to the gate of the power transistor when ESD occurs on the negative terminal of the DC power supply of the power module, thereby improving the yield of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and other purposes, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0035] Figure 1 A schematic diagram of the circuit structure of a power module provided according to the utility model is shown;

[0036] Figure 2 An internal perspective view of a power module provided according to the utility model is shown;

[0037] Figure 3 The pin distribution diagram of the driving circuit of the power module provided by the utility model is shown;

[0038] Figure 4a and Figure 4b A cross-sectional schematic diagram and a pin side view of the packaging structure of the power module provided by the utility model are respectively shown;

[0039] Figure 5 A three-dimensional schematic diagram of a power module provided according to the utility model is shown. DETAILED DESCRIPTION

[0040] The present invention will be described in more detail below with reference to the accompanying drawings. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale. In addition, some well-known parts may not be shown. Many specific details of the present invention are described below, but as those skilled in the art will appreciate, the present invention may not be implemented in accordance with these specific details.

[0041] The present invention may be embodied in various forms, some examples of which will be described below.

[0042] Figure 1 FIG. 1 is a schematic diagram showing a circuit structure of a power module provided by the utility model. Figure 1 As shown, the power module 100 includes a half-bridge driving circuit, wherein the half-bridge driving circuit includes a driving circuit A1, a corresponding half-bridge circuit, and a bootstrap diode D1 connected between the power supply terminal VCC of the driving circuit A1 and the high-side driving floating power supply terminal VB. It should be noted that Figure 1 The half-bridge drive circuit shown in FIG. 1 can be any one of the U phase, V phase or W phase in the three-phase half-bridge drive circuit.

[0043] Furthermore, the half-bridge circuit includes a high-side transistor Q1 and a low-side transistor Q2. In this embodiment, the high-side transistor Q1 and the low-side transistor Q2 are one of MOS devices, RC-IGBT devices, IGBT devices and fast recovery diodes.

[0044] When the transistor is a MOS device, the first end of the transistor is the drain, the second end is the source, and the control end is the gate; when the transistor is an IGBT device, the first end of the transistor is the collector, the second end is the emitter, and the control end is the base.

[0045] Compared with the traditional layout in which the high-side transistor Q1 is placed above the low-side transistor Q2, the power module 100 of this embodiment places the high-side transistor Q1 below the low-side transistor Q2, thereby reducing the wire bonding length of the source electrode of the high-side transistor Q1 and the output / high-side drive floating power supply ground terminal VS, reducing the risk of wire collapse when bonding on the package structure, and is conducive to improving the package yield rate. In addition, through this arrangement, the DC power supply positive terminal P and the DC power supply negative terminal N of the package structure can also be set on the same side of the lead frame, which is convenient for the PCB wiring of the peripheral electrolytic capacitor.

[0046] See also Figure 1 The power module 100 includes multiple pins, and the pin names and descriptions are shown in the following table.

[0047] Table 1. Power module pin names and descriptions

[0048] Pin Name describe VB(1) High-side driver floating power supply terminal N1(2) The first DC power supply negative terminal VCC(3) Power supply HIN(4) High-side signal input LIN(5) Low-side signal input SD / VFO(6) Enable input terminal / fault alarm signal output terminal CSC(7) Short circuit current detection input COM(8) Public land N2(9) Second DC power supply negative terminal P(10) DC power supply positive terminal VB(11) High-side driver floating power supply terminal VS(12) Output / high-side driver floating power supply ground

[0049] In the power module 100, the first end of the high-side transistor Q1 is connected to the DC power supply terminal P (10), the control end of the high-side transistor Q1 is connected to the high-side drive signal output terminal HO of the drive circuit A1, and the intermediate node between the second end of the high-side transistor Q1 and the first end of the low-side transistor Q2 is connected to the high-side drive suspension power supply terminal VS of the drive circuit A1, and serves as the output / high-side drive suspension power supply ground terminal VS (12) of the power module 100. The control end of the low-side transistor Q2 is connected to the low-side drive signal output terminal LO of the drive circuit A1, and the second end of the low-side transistor Q2 is connected to the reference ground terminal VSS of the drive circuit A1 and the first DC power supply negative terminal N1 (2) and the second DC power supply negative terminal N2 (9). The anode of the bootstrap diode D1 is connected to the power supply terminal VCC of the drive circuit A1 and serves as the power supply terminal VCC (3) of the power module 100. The cathode of the bootstrap diode D1 is connected to the high-side drive suspension power supply terminal VB of the drive circuit A1 and serves as the high-side drive suspension power supply terminal VB (1) on the first side and the high-side drive suspension power supply terminal VB (11) on the second side of the power module 100. The high-side signal input terminal HIN of the drive circuit A1 serves as the high-side signal input terminal HIN (4) of the power module 100. The low-side signal input terminal LIN of the drive circuit A1 serves as the low-side signal input terminal LIN (5) of the power module 100. The signal ground terminal COM of the drive circuit of the drive circuit A1 serves as the common ground terminal COM (8) of the power module 100.

[0050] Furthermore, the driving circuit A1 of this embodiment also has a short circuit / overcurrent detection function and an enable control / fault signal output function. The enable input terminal / fault alarm signal output terminal SD / VFO of the driving circuit A1 serves as the enable input terminal / fault alarm signal output terminal SD / VFO (6) of the power module 100, and the short circuit current detection input terminal CSC of the driving circuit A1 serves as the short circuit current detection input terminal CSC (7) of the power module 100. The driving circuit A1 is provided with an overcurrent detection unit for overcurrent / short circuit detection, and the overcurrent detection unit detects the current detection input signal provided by the short circuit current detection input terminal CSC of the driving circuit, and then outputs a fault alarm signal from the enable input terminal / fault alarm signal output terminal SD / VFO based on the detection result.

[0051] The improved power module provided in the utility model encapsulates the single-phase half-bridge circuit and the drive circuit in one package, so the use of three of the above-mentioned power modules can also realize the function of three-phase motor driving, and compared with the traditional three-phase intelligent power module, the power module of the utility model has a more compact total area, and can realize decentralized and flexible layout according to the shape of the printed circuit board to reduce the area of ​​the printed circuit board.

[0052] On the other hand, the power module provided by the utility model can realize the packaging of the final power module by designing the package body based on the standard package that can be mounted, so that the final power module can be packaged by braiding, installed by surface mounting technology (SMT), and efficiently processed by automatic mounting machines during printed circuit board (PCB) processing, which can greatly improve production efficiency and processing reliability. In terms of thermal performance, the single-phase power module formed based on the package body is not easy to produce heat accumulation effect, which is conducive to heat dissipation and effectively reduces temperature rise.

[0053] In addition, the pins of the power module of the utility model can be arranged freely, making the PCB layout more flexible. When there is a chip damage, only the chip corresponding to one phase needs to be replaced, and there is no need to replace the three-phase intelligent power module as a whole, which reduces the cost of research and development and production. In addition, the single-phase power module is less likely to produce problems such as delamination due to its small package volume and smaller package stress, which can improve the yield and efficiency of production. In addition, reducing the package volume can also reduce the wire bonding distance between internal chips, which can effectively reduce the occurrence of problems such as wire punching and wire collapse during the packaging process, and improve the yield of packaging.

[0054] On the other hand, the high-side transistor is arranged below the low-side transistor in the package structure, so that the wire bonding length of the source electrode of the high-side transistor Q1 and the output / high-side drive floating power supply ground terminal VS can be reduced, reducing the risk of wire collapse when bonding on the package structure, which is conducive to improving the package yield rate. In addition, through this arrangement, the DC power supply positive terminal P and the DC power supply negative terminal N of the package structure can be arranged on the same side of the lead frame, which is convenient for the PCB wiring of the peripheral electrolytic capacitor.

[0055] On the other hand, two high-side drive floating power supply terminals VB (1 and 11) are extended in the power module 100, so that the high-side drive floating power supply terminal VB and the output / high-side drive floating power supply ground terminal VS can be arranged adjacent to each other on the same side of the lead frame, which is convenient for connecting the bootstrap capacitor between the positive and negative terminals of the high-side IGBT drive power supply and optimizing the PCB routing in the drive circuit.

[0056] Figure 2 An internal perspective view of a power module provided according to a first embodiment of the utility model is shown. Figure 3 The figure shows the pin distribution diagram of the driving circuit A1 of the power module provided by the present invention.

[0057] The interior of the driving circuit A1 is designed according to the circuit structure of the driving circuit. The driving circuit A1 includes functional pins (see Figure 1 The pins of the driving circuit shown in FIG.

[0058] like Figure 2 As shown, the power module 200 includes a lead frame 210, wherein the lead frame 210 is placed together with a plurality of chips, and after being plastic-sealed to further form a plastic-sealed body, is cut to form an independent package body. The package line 201 of the lead frame 210 is schematically indicated by a dotted frame, wherein the package line 201 is the boundary line of the plastic-sealed body to be formed after plastic-sealing.

[0059] Furthermore, the power module 220 also includes a plurality of base islands 221-224, a plurality of pins, and a driving circuit A1, a bootstrap diode BSD, a high-side transistor Q1, and a low-side transistor Q2 arranged on the corresponding base islands. The plurality of base islands 221-224 are distributed on the lead frame 210 in the shape of a four-leaf clover. It should be noted that "four-leaf clover distribution" is not a standard engineering or design term, it may be a figurative metaphor used to describe a specific layout or distribution method. In the lead frame design of an integrated circuit, "four-leaf clover distribution" may refer to distributing different parts or functional modules of the circuit in a shape similar to a four-leaf clover, each "leaf" represents a functional area, and the center may represent a core processing unit or other key components. The purpose of this layout may be to optimize performance, heat dissipation, signal integrity, or power management.

[0060] Further, the multiple base islands 221-224 include 1 small base island 221, 1 medium base island 222, and 2 large base islands 223 and 224. Among them, in the present application, the terms "large base island", "medium base island" and "small base island" have the following definitions: in the same packaging frame, the base island with a relatively large area is a large base island, the base island with a relatively small area is a small base island, and the base island with an area between the large base island and the small base island is a medium base island. Further, the setting positions of the small base island 221, the medium base island 222, and the large base islands 223 and 224 can be set according to actual needs. For example, in the present embodiment, the small base island 221 is set at the upper left position of the lead frame 210, the medium base island 222 is set at the lower left position of the lead frame, and the large base islands 223 and 224 are respectively set at the upper right and lower right positions of the lead frame 210. The bootstrap diode BSD is arranged on the small base island 221, the driving circuit A1 is arranged on the medium base island 222, the high-side transistor Q1 is arranged on the large base island 224, and the low-side transistor Q2 is arranged on the large base island 223. In an optional embodiment, the bootstrap diode BSD may also be integrated into the driving chip A1, and the present invention does not limit this.

[0061] Further, the power module 200 includes a first side 211 and a second side 212 that are arranged opposite to each other, and a third side 213 and a fourth side 214 that are arranged opposite to each other, wherein the first side 211 and the second side 212 extend along a first direction in the figure, and the third side 213 and the fourth side 214 extend along a second direction in the figure, and the first side 211 and the third side 213 are perpendicular. In addition, in the power module 200 of the present embodiment, the high-side transistor Q1 and the low-side transistor Q2 are close to the second side 212 of the lead frame 210, the bootstrap diode BSD and the low-side transistor Q2 are close to the third side 213 of the lead frame 210, the drive circuit A1 and the high-side transistor Q1 are close to the fourth side 214 of the lead frame 210, and the bootstrap diode BSD and the drive circuit A1 are close to the first side 211 of the lead frame 210.

[0062] The plurality of pins include a plurality of high-voltage pins and a plurality of low-voltage pins, wherein the plurality of low-voltage pins are arranged on the first side 211 of the lead frame 210, and the plurality of high-voltage pins are arranged on the first side 211 and the second side 212 of the lead frame 210. Further, the high-voltage pins include Figure 1 and Figure 2The DC power supply positive terminal P, DC power supply negative terminals N1 and N2, high-side drive floating power supply terminal VB and output / high-side drive floating power supply ground terminal VS are shown in the figure. The multiple low-voltage pins include multiple control signal pins, multiple analog signal pins and multiple I / O signal pins. The control signal pins include: a high-side signal input terminal HIN and a low-side signal input terminal LIN, etc. The multiple analog signal pins include a power supply terminal VCC, a short-circuit current detection input terminal CSC, etc. The multiple I / O signal pins include an enable input terminal / fault alarm signal output terminal SD / VFO, etc.

[0063] It should be noted that, in this application, the term "high voltage pin" refers to a pin in a chip or packaging structure that may be in a high voltage state, and the term "low voltage pin" refers to a pin in a chip or packaging structure that is always in a low voltage state.

[0064] In this embodiment, the high-side transistor Q1 and the low-side transistor Q2 are MOS devices or RC-IGBT devices.

[0065] Further, at least one end of the small base island 221 serves as the high-side drive floating power supply terminal VB of the power module 200, and the high-side drive floating power supply terminal VB is located on the first side 211 and the second side 212 of the lead frame 210. For example, the side of the small base island 221 close to the first side 211 extends the pins to the outside of the plastic package of the lead frame 210 to form the pin 1 of the high-side drive floating power supply terminal VB, and the side of the small base island 221 away from the first side 211 extends the pins to the outside of the plastic package of the lead frame 210 to form the pin 11 of the high-side drive floating power supply terminal VB located on the second side 212. In this way, the high-side drive floating power supply terminal VB and the output / high-side drive floating power supply ground terminal VS can be arranged adjacent to each other on the second side 212 of the lead frame 210, which is convenient for connecting the bootstrap capacitor between the positive and negative terminals of the high-side IGBT drive power supply, and optimizing the PCB routing in the drive circuit.

[0066] At least one end of the middle base island 222 serves as the common ground terminal COM of the power module 200, and the common ground terminal COM is located on the first side 211 of the lead frame 210. For example, the middle base island 222 extends a pin toward the outside of the plastic package of the lead frame 210 on one side close to the first side 211 to form the pin 8 of the common ground terminal COM, and then the pin COM of the driving circuit A1 is electrically connected to the extended structure of the middle base island 222 through a bonding wire, so that the signal ground terminal COM of the driving circuit A1 can be used as the common ground terminal COM (8) of the power module. Furthermore, the other end of the middle base island 222 also extends toward the first side of the lead frame 210, but does not extend outside the plastic package to improve the stability of the power module. Since the other end of the base island 222 also extends toward the first side of the lead frame 210 , the distance between the DC power supply negative terminal N1 (pin 2 ) and the power supply terminal VCC (pin 3 ) is wider than the distance between adjacent pins from pins 4 to 9 .

[0067] Furthermore, the power module 200 further includes a plurality of independent pins disposed on the first side 211 and extending to the outside of the plastic package of the lead frame 210 to form leads, for example Figure 2 The pins 3-7 shown in the figure are connected to the functional pins of the driving circuit A1 through bonding wires to form a power supply terminal VCC, a high-side signal input terminal HIN, a low-side signal input terminal LIN, an enable input terminal / fault alarm signal output terminal SD / VFO, and a short-circuit current detection input terminal CSC, etc. Further, the shape and length of the pins of the independent pins 3-7 leading out of the plastic package are the same as the shape and length of the pins extending out of the plastic package from the base island 222.

[0068] At least one end of the large base island 224 serves as the DC power supply positive terminal P of the power module 200, and the DC power supply positive terminal P is located on the second side 212 of the lead frame 210. For example, the large base island 224 extends a pin toward the outside of the plastic package of the lead frame 210 on one side close to the second side 212 to form a plurality of pins (10) of the DC power supply positive terminal P. By providing a plurality of pins 10 of the DC power supply positive terminal P on the second side 212 of the power module 200, the heat generated by the high-side transistor Q1 during operation can be transferred to the external whole machine board through the plurality of pins (10), thereby effectively reducing the operating temperature of the high-side transistor Q1.

[0069] At least one end of the large base island 223 serves as the output / high-side drive suspension power supply ground terminal VS of the power module 200, and the output / high-side drive suspension power supply ground terminal VS is located on the second side 212 of the lead frame 210. For example, the large base island 223 extends a pin toward the outside of the plastic package of the lead frame 210 on one side close to the second side 212, thereby forming a plurality of pins (12) of the output / high-side drive suspension power supply ground terminal VS. Similarly, by providing a plurality of pins (12) of the output / high-side drive suspension power supply ground terminal VS on the second side 212, the heat generated by the low-side transistor Q2 during operation can be transferred to the external whole machine board through the plurality of pins (12), which facilitates the heat dissipation of the power chip during operation, and can effectively reduce the operating temperature of the low-side transistor Q2.

[0070] Furthermore, the distance between the DC power supply positive terminal P (pin 10) on the second side and the high-side driving floating power supply terminal VB (pin 11) on the second side is wide enough to increase the electrical gap to achieve isolation.

[0071] Furthermore, the large base island 223 extends toward the third side of the lead frame to form a "small ear" conductive structure, and the large base island 224 extends toward the fourth side of the lead frame to form a "small ear" conductive structure, which enhances the stability of the two large base islands in the power module.

[0072] Through the above configuration, a large area of ​​external heat sink can be saved on the power module 200, which can not only reduce the production cost but also help to improve the space utilization of the PCB layout.

[0073] It should be noted that, in order to facilitate packaging, the multiple pins on the first side 211 and the second side 212 of this embodiment have the same length and width. However, in other embodiments, pins of different widths can be set on the first side 211 and the second side 212 according to specific heat dissipation and power requirements. The present invention is not limited to this.

[0074] Furthermore, the power module 200 also includes an inverted C-shaped conductive structure 230 disposed on the lead frame 210, and the "inverted C-shaped" means that the conductive structure 230 is shaped like an inverted "C". The conductive structure 230 extends along the first direction, and both ends of the conductive structure 230 extend to the first side 211, the high-side transistor Q1 and the low-side transistor Q2 are located between the second side 212 of the lead frame 210 and the conductive structure 230, the bootstrap diode BSD is located between the third side 213 of the lead frame 210 and the conductive structure 230, and the drive circuit A1 is located in the enclosed space formed by the first side 211 of the lead frame 210 and the conductive structure 230.

[0075] By using the conductive structure 230 to separate the power transistor chips Q1 and Q2 whose temperatures rise faster during operation from the drive circuit A1, thermal isolation between the drive circuit and the power chip can be achieved, thereby reducing the temperature rise rate of the drive circuit during operation and improving the working efficiency of the power module 200.

[0076] Further, at least one end of the conductive structure 230 serves as the negative DC power supply terminal N of the power module 200. For example, at least one end of the conductive structure 230 extends toward the first side 211 and extends out of the plastic package of the lead frame 210 to form a pin, and then forms a pin of the negative DC power supply terminal N. Further, both the first end and the second end of the conductive structure 230 extend the pins to the outside of the plastic package of the lead frame 210 to form a pin 2 of the first negative DC power supply terminal N1 close to the third side 213 and a pin 9 of the second negative DC power supply terminal N2 close to the fourth side 214 on the first side 211, respectively. In this embodiment, since the second negative DC power supply terminal N2 and the positive DC power supply terminal P are both close to the fourth side 214 of the lead frame 210, the wiring length and difficulty of the peripheral electrolytic capacitor PCB can be reduced, thereby improving efficiency.

[0077] In the power module 200, the first end of the high-side transistor Q1 is electrically connected to the pin 10 of the DC power supply positive terminal P through the extended structure of the large base island 224, the control end of the high-side transistor Q1 is electrically connected to the pin HO of the driving circuit A1 through the bonding wire, the second end of the high-side transistor Q1 is electrically connected to the first end of the low-side transistor Q2 and the pin 12 of the output / high-side driving floating power supply ground terminal VS through the bonding wire and the large base island 223, the control end of the low-side transistor Q2 is electrically connected to the pin LO of the driving circuit A1 through the bonding wire, the second end of the low-side transistor Q2 is electrically connected to the conductive structure 230 through the bonding wire, and then electrically connected to the pins 2 and 9 of the DC power supply negative terminals N1 and N2. The pin VB of the driving circuit A1 is electrically connected to the extended structure of the small base island 221 through the bonding wire, and then electrically connected to the pins 1 and 11 of the high-side driving floating power supply terminal VB.

[0078] Furthermore, the driving circuit A1 also includes a functional pin of a reference ground terminal VSS, and the reference ground terminal VSS is electrically connected to the conductive structure 230 through a bonding wire, and then electrically connected to the pin of the DC power supply negative terminal N. In this embodiment, by providing a functional pin of the reference ground terminal VSS on the driving circuit A1, and electrically connecting the pin to the DC power supply negative terminal N of the power module 200 through a bonding wire and the conductive structure 230, the driving circuit A1 and the power transistor can be grounded together, and then damage to the gate of the power transistor when ESD occurs on the DC power supply negative terminal N of the power module 200 can be avoided, thereby improving the yield of the product.

[0079] Figure 4a and Figure 4b The schematic cross-sectional view and the side view of the pins of the packaging structure of the power module provided by the utility model are respectively shown. Figure 5 The following is a three-dimensional schematic diagram of a power module provided by the utility model. Specifically, Figure 4a A cross-sectional view along the direction of the driving circuit A1 and the high-side transistor is shown, Figure 4b A side view of the second side is shown. Figure 4a As shown, the power module 300 includes: a lead frame 310, a driving circuit 320, a power chip 330 and a plastic package 340. The plastic package 340 covers the driving circuit 320, the power chip 330 and part of the lead frame 310, and the pins 370 and 380 of the lead frame 310 are located outside the plastic package 340 for electrical connection. Specifically, the packaging structure of the power module 300, in addition to the driving circuit 320 and the power chip 330, also includes, for example, a bootstrap diode (BSD) (not shown in the figure), etc. The above-mentioned chips or other semiconductor structures are, for example, all located on a base island 350 provided on the lead frame 310, and are all located on the first surface of the lead frame 310, and the chips, semiconductor structures and pins on the lead frame 310 are electrically connected, for example, through bonding wires 360. Further, the lead frame 310 includes a plurality of base islands 350, and the drive circuit 320, the power chip 330, and the bootstrap diode not shown are respectively located on different base islands 350, and the base islands 350 are all in the same plane. The plastic package 340 covers the above-mentioned drive circuit 320, the power chip 330, the bootstrap diode, the bonding wire 360, and the base island 350 part of the lead frame 310, and only the pins 370 and 380 extend from the plastic package 340, and the pins 370 and 380 are bent toward the second surface of the lead frame 310 opposite to the first surface. Further, the pins 370 on the lead frame 310 are, for example, formed by the base island 350 below the power chip 330 extending out of the plastic package 340, and the pins 380 on the lead frame 310 are independent pins, and are electrically connected to the functional pins on the drive circuit 320 through bonding wires. Furthermore, in order to meet the electrical safety requirements, the second surface (back side of the base island) of the lead frame 310 opposite to the first surface 111 is also covered by the package body 300. Figure 4b As shown, the lead frame of the power module extends outside the plastic package and is bent to form pins, which is beneficial to heat dissipation.

[0080] The power module provided according to the utility model can be applied to electronic devices. The electronic devices equipped with the utility model can not only improve the robustness and reliability of the product, but also improve the production yield of the product and reduce the production cost of the product. In the embodiment of the utility model, the bonding wires in the power module include but are not limited to aluminum wires, aluminum strips, gold wires and copper wires. The lead frame of the power module is partially silver-plated to reduce the contact resistance between the chip and the lead frame to ensure good contact between the chip. The power module contains power chips such as insulated gate bipolar transistors, metal-oxide semiconductor field effect transistors, fast recovery diodes and bootstrap diodes, and the driving chips include but are not limited to half-bridge driving chips, high-voltage driving chips and low-voltage driving chips. In the utility model, the welding materials used inside the power module include but are not limited to solder paste, silver paste, tin sheets and tin wires, which is conducive to reducing the contact resistance between the internal structures of the power module and improving the electrical connection reliability of the power module.

[0081] The above-mentioned intelligent power modules are all described by taking a single-sided board as an example, but it can be understood that the solution disclosed in this application can also be adopted in the case of a double-sided board.

[0082] It should be noted that, 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 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 other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0083] The embodiments of the present invention are described above, and these embodiments do not describe all the details in detail, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modifications based on the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A power module, characterized in that: include: lead frame, driver circuit, low-side transistor and high-side transistor, The lead frame includes a plurality of base islands and a plurality of pins. The power module comprises a first side and a second side that are arranged opposite to each other, and a third side and a fourth side that are arranged opposite to each other, the first side and the second side extend along a first direction, the third side and the fourth side extend along a second direction, the first side and the third side are perpendicular, The plurality of base islands include a first base island, a second base island, a third base island and a fourth base island, the driving circuit is located on the second base island, the low-side transistor is located on the third base island, and the high-side transistor is located on the fourth base island, The high-side transistor and the low-side transistor are close to the second side, the first base island and the low-side transistor are close to the third side, and the driving circuit and the high-side transistor are close to the fourth side.

2. The power module according to claim 1, characterized in that: The first base island and the driving circuit are close to the first side.

3. The power module according to claim 2, characterized in that: The first base island extends a high-side driving suspension power supply terminal toward the first side and the second side respectively.

4. The power module according to claim 3, characterized in that: The high-side driving suspension power supply terminal on the first side is close to the third side, The third base island extends toward the second side to lead out an output / high-side driver suspension power supply ground terminal, and the high-side driver suspension power supply terminal on the second side is adjacent to the output / high-side driver suspension power supply ground terminal.

5. The power module according to claim 4, characterized in that: The high-side driving floating power supply terminal on the second side and the output / high-side driving floating power supply ground terminal are used to connect a bootstrap capacitor.

6. The power module according to claim 4, characterized in that: The output / high-side driving suspension power supply ground terminal extends a plurality of pins to the outside of the plastic package body.

7. The power module according to claim 2, characterized in that: The fourth base island extends toward the second side, leading out a DC power supply positive terminal electrically connected to the first terminal of the high-side transistor, and the DC power supply positive terminal is located on the second side and close to the fourth side.

8. The power module according to claim 7, characterized in that: The DC power supply positive terminal extends a plurality of pins to the outside of the plastic package body.

9. The power module according to claim 3, characterized in that: The high-side driving suspension power supply terminal on the first side and the high-side driving suspension power supply terminal on the second side are electrically connected to the high-side driving suspension power supply terminal of the driving circuit.

10. The power module according to claim 2, characterized in that: Two ends of the second base island extend toward the first side respectively, leading out a common ground terminal electrically connected to the common ground terminal of the driving circuit, and one end of the second base island close to the fourth side extends a pin out of the plastic package body.

11. The power module according to claim 10, characterized in that: The lead frame extends toward the first side to lead out a plurality of pins connected to the functional pins of the driving circuit.

12. The power module according to claim 2, characterized in that: Also includes: A conductive structure is arranged on the lead frame, the conductive structure extends along the first direction, the conductive structure includes a first end and a second end, the first end and the second end extend to two ends of the first side respectively, and the second base island is placed in a space enclosed by the conductive structure and the first side.

13. The power module according to claim 12, characterized in that: The first end of the conductive structure and / or the second end of the conductive structure serve as a negative terminal of a direct current power supply electrically connected to the low-side transistor.

14. The power module according to claim 13, characterized in that: The first end and the second end of the conductive structure both extend pins to the outside of the plastic package of the lead frame to form a first DC power supply negative terminal and a second DC power supply negative terminal, respectively. Wherein, the first DC power supply negative terminal is located between the high-side floating power supply terminal on the first side and a plurality of pins connected to the functional pins of the driving circuit, The second DC power supply negative terminal is located at the first side and close to the fourth side.

15. The power module according to claim 14, characterized in that: The DC power supply positive terminal and the second DC power supply negative terminal are both close to the fourth side, and an electrolytic capacitor is connected between the DC power supply positive terminal and the second DC power supply negative terminal.

16. The power module according to claim 13, characterized in that: The second terminal of the low-side transistor is electrically connected to the conductive structure through a bonding wire.

17. The power module according to claim 13, characterized in that: The driving circuit also includes a reference ground pin, and the reference ground pin of the driving circuit is electrically connected to the conductive structure through a bonding wire.

18. The power module according to claim 1, characterized in that: It also includes a bootstrap diode, which is located on the first base island or integrated in the driving circuit.

19. The power module according to claim 1, characterized in that: The high-side transistor and the low-side transistor are one of a MOS device, an RC-IGBT device, an IGBT device and a fast recovery diode.

20. The power module according to claim 19, characterized in that: The high-side transistor and the low-side transistor are MOS devices, and the first end of the transistor, the second end of the transistor and the control end of the transistor are a drain, a source and a gate respectively.

21. The power module according to claim 19, characterized in that: The high-side transistor and the low-side transistor are IGBT devices, RC-IGBT devices or IGBT devices and fast recovery diodes, and the first end of the transistor, the second end of the transistor and the control end of the transistor are respectively the collector, the emitter and the base.

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