Intelligent power module

Abstract

The utility model provides an intelligent power module. A first substrate, a second substrate, an optocoupler isolation drive circuit module and a power circuit module are arranged in the intelligent power module. The optocoupler isolation driving circuit module is arranged on the first substrate, the power circuit module is arranged on the second substrate, and the first substrate is electrically connected with the power circuit module; wherein; and the optocoupler isolation driving circuit module is used for receiving an external control signal and sending an internal control signal corresponding to the external control signal to the power circuit module. The isolation driving circuit is integrated in the intelligent power module, so that the isolation requirement of electrical safety can be met, the system integration degree is improved, the overall parasitic inductance is reduced, meanwhile, the isolation driving circuit is arranged on the first substrate, the arrangement of leads in the intelligent power module can be reduced, common-mode interference is reduced, and the service life of the intelligent power module is prolonged. The reliability of the intelligent power module is improved, and on the basis, setting of higher voltage and frequency can be achieved.

Description

Technical Field

[0001] This utility model relates to the field of electronic devices, and in particular to an intelligent power module. Background Technology

[0002] An IPM (Intelligent Power Module) is a multi-chip structure module that encapsulates power device chips and protection driver chips or circuits within the same insulator. With the development of power semiconductor technology, the power that IPMs can handle is gradually increasing. The voltage and switching frequency that traditional silicon-based chips can withstand are no longer sufficient to meet the growing demands. However, with the development of silicon carbide (SiC), a third-generation semiconductor material capable of withstanding higher voltages and frequencies, SiC discrete devices and integrated power modules are already being used in home appliances, new energy vehicles, and other fields.

[0003] However, for IPMs that integrate drive and protection functions into the same module, reliability issues such as common-mode interference and lack of electrical isolation limit the IPM's ability to achieve higher voltage and higher frequency specifications. Utility Model Content

[0004] The main purpose of this invention is to propose an intelligent power module, which aims to solve the problem that the reliability of existing IPMs prevents the application of higher voltage and higher frequency specifications.

[0005] To achieve the above objectives, this utility model provides an intelligent power module, which includes a first substrate, a second substrate, an optocoupler isolation driving circuit module, and a power circuit module; the optocoupler isolation driving circuit module is disposed on the first substrate, and the power circuit module is disposed on the second substrate, with the first substrate and the power circuit module being electrically connected; wherein;

[0006] The optocoupler-isolated drive circuit module is used to receive external control signals, and after optocoupler isolation of the external control signals, send the internal control signals corresponding to the external control signals to the power circuit module.

[0007] Optionally, the first substrate is a printed circuit board, and the second substrate is a ceramic copper-clad laminate.

[0008] Optionally, the optocoupler isolation drive circuit module includes an isolation unit and a signal output unit, and the power circuit module includes multiple power devices, with the signal output unit connected to each power device in a one-to-one correspondence; wherein:

[0009] One set of output terminals of the isolation unit is connected to one of the signal output units.

[0010] Optionally, the isolation unit includes a processing chip and an optical coupler subunit; the optical coupler subunit includes multiple optical coupler components, and the output terminal of the optical coupler components serves as the output terminal of the isolation unit;

[0011] The output terminals of the processing chip are connected one-to-one with the control terminals of the optocoupler assembly; wherein:

[0012] The processing chip is used to receive external control signals and control the conduction state of the corresponding optocoupler subunit according to the external control signals, so that the optocoupler subunit outputs the corresponding internal control signal.

[0013] Optionally, the optocoupler assembly includes a molding compound, a reflective layer, a transparent material, a light-emitting diode, and a photosensitive driver chip; wherein:

[0014] The encapsulation and the first substrate form a receiving space. The light-emitting diode and the photosensitive driving chip are disposed on the first substrate within the receiving space. The transparent material fills the receiving space to form a transmissive layer. The reflective layer is disposed between the encapsulation and the transmissive layer. The positive terminal of the light-emitting diode is connected to the output terminal of the processing chip, and the negative terminal of the light-emitting diode is grounded. The output terminal of the photosensitive driving chip serves as the output terminal of the optocoupler assembly.

[0015] Optionally, the two electrodes of the light-emitting diode are disposed on the same side; the positive electrode of the light-emitting diode is connected to the output terminal of the processing chip through the internal circuit of the first substrate, and the negative electrode of the light-emitting diode is grounded through the internal circuit of the first substrate.

[0016] Optionally, the two electrodes of the light-emitting diode are disposed on opposite sides; the first electrode of the light-emitting diode is connected to the outside through the internal circuit of the first substrate; the second electrode of the light-emitting diode is connected to the corresponding pad on the first substrate through a bonding wire, and the pad is connected to the outside through the internal circuit of the first substrate.

[0017] Optionally, a set of output terminals of the isolation unit includes a signal output terminal; the signal output unit includes a first resistor; wherein:

[0018] The first resistor is connected between the signal output terminal of the isolation unit and the gate of the power device.

[0019] Optionally, the signal output unit further includes a second resistor and a first diode; wherein:

[0020] The negative terminal of the first diode is connected to the signal output terminal of the isolation unit, the positive terminal of the first diode is connected to the first terminal of the second resistor, and the second terminal of the second resistor is connected to the gate of the power device.

[0021] Optionally, the isolation unit includes an upper transistor output terminal, which includes an upper transistor high-voltage terminal and an upper transistor ground terminal; the signal output unit includes a negative voltage drive subunit, which includes a first capacitor, a second capacitor, a first Zener diode, and a third resistor; wherein:

[0022] The positive terminal of the Zener diode is connected to the ground terminal of the isolation unit, the negative terminal of the Zener diode is connected to the source terminal of the power device, the negative terminal of the Zener diode is also connected to the first terminal of the third resistor, the second terminal of the third resistor is connected to the high-voltage terminal of the isolation unit, the first capacitor is connected in parallel with the third resistor, and the second capacitor is connected in parallel with the Zener diode.

[0023] Optionally, the isolation unit includes an upper transistor output terminal, which includes an upper transistor high-voltage terminal and an upper transistor ground terminal; the optocoupler isolation drive circuit module further includes a bootstrap unit, which includes a fourth resistor, a second diode, and a third capacitor; wherein:

[0024] The first end of the fourth resistor is connected to the driving power supply, the second end of the fourth resistor is connected to the positive terminal of the second diode, the negative terminal of the second diode is connected to the high voltage terminal of the upper tube of the isolation unit, the first end of the third capacitor is connected to the high voltage terminal of the upper tube of the isolation unit, and the second end of the third capacitor is connected to the ground terminal of the upper tube of the isolation unit.

[0025] Optionally, the intelligent power module further includes a lead frame; wherein:

[0026] The lead frame is electrically connected to the first substrate, the second substrate, and the power circuit module, respectively, and is used to lead out the electrodes on the first substrate, the second substrate, and the power circuit module to the corresponding pins.

[0027] This invention proposes an intelligent power module, which includes a first substrate, a second substrate, an optocoupler isolation drive circuit module, and a power circuit module. The optocoupler isolation drive circuit module is disposed on the first substrate, and the power circuit module is disposed on the second substrate, with the first substrate and the power circuit module electrically connected. The optocoupler isolation drive circuit module receives external control signals, optically isolates the drive side receiving the external control signals from the power side where the power circuit module is located, and then sends an internal control signal corresponding to the external control signals to the power circuit module. By integrating the isolation drive circuit into the intelligent power module, the electrical safety isolation requirements are met, the system integration is improved, and the overall parasitic inductance is reduced. Furthermore, placing the isolation drive circuit on the first substrate reduces the number of leads within the intelligent power module, lowers common-mode interference, and improves the reliability of the intelligent power module. Based on this, higher voltage and frequency settings can be achieved. Attached Figure Description

[0028] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the present invention.

[0029] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0031] Figure 1 This is a module structure diagram of the first embodiment of the intelligent power module of this utility model;

[0032] Figure 2 This is a side sectional view of the intelligent power module of this utility model;

[0033] Figure 3 This is a circuit structure diagram of an embodiment of the intelligent power module of this utility model;

[0034] Figure 4 This is a circuit diagram of another embodiment of the intelligent power module of this utility model;

[0035] Figure 5This is a structural diagram of an embodiment of the optocoupler component in the intelligent power module of this utility model;

[0036] Figure 6 This is a structural diagram of another embodiment of the optocoupler component in the intelligent power module of this utility model;

[0037] Figure 7 This is a schematic diagram of the intelligent power module of this utility model;

[0038] Figure 8 This is a schematic diagram of the layout structure of the intelligent power module of this utility model.

[0039] Explanation of icon numbers:

[0040]

[0041] Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0043] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0044] It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention. To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0045] This utility model provides an intelligent power module, referring to... Figure 1 , Figure 1This is a structural diagram of the first embodiment of the intelligent power module of this utility model. The intelligent power module includes a first substrate 100, a second substrate 200, an optocoupler isolation driving circuit module 300, and a power circuit module 400. The optocoupler isolation driving circuit module 300 is disposed on the first substrate 100, and the power circuit module 400 is disposed on the second substrate 200. The first substrate 100 and the power circuit module 400 are electrically connected.

[0046] The optocoupler isolation drive circuit module 300 is used to receive external control signals, and after optocoupler isolation of the external control signals, send the internal control signals corresponding to the external control signals to the power circuit module 400.

[0047] The optocoupler isolation drive circuit module 300 is used to achieve electrical isolation within the intelligent power module via optocouplers.

[0048] The optocoupler isolation drive circuit module 300 includes optocoupler isolation drive devices, and the specific device type can be set according to actual needs.

[0049] The power circuit module 400 is used to perform the power drive function of the intelligent power module.

[0050] The power circuit module 400 includes power switching devices, and the specific type and structure of the power switching devices can be set according to actual needs.

[0051] The external control signal is a control signal sent by an external controller connected to the intelligent power module. It can be understood that the external control signal is sent from the external controller to the intelligent power module. The optocoupler isolation drive circuit module 300 in the intelligent power module receives the external control signal and performs optocoupler isolation on the external control signal. At the same time, it outputs an internal control signal corresponding to the external control signal to the power circuit module 400. The power circuit module 400 executes the switching action corresponding to the external control signal based on the control of the internal control signal, and then outputs power based on the executed switching action.

[0052] For silicon carbide smart power modules operating in high-voltage, high-frequency environments, the capacitance to ground generates common-mode current flowing through the signal path. Simultaneously, impedance asymmetry creates differential-mode voltage interference, both of which can cause malfunctions in the power circuit module 400. By incorporating an optocoupler-isolated drive circuit module 300, electrical isolation between the drive side receiving external control signals and the power side where the power circuit module is located improves anti-interference capabilities and reduces common-mode interference. Furthermore, integrating the optocoupler-isolated drive circuit module 300 within the smart power module, rather than placing it in an external circuit, increases the overall system integration, reduces parasitic effects in high-frequency operating environments, and enhances the overall system safety against accidental electric shock. Therefore, it is possible to achieve silicon carbide smart power modules with higher voltage and frequency specifications.

[0053] Existing smart power modules typically use lead frames to electrically connect components. However, this method uses a large number of bonding wires, resulting in significant parasitic capacitance within the smart power module, which cannot meet the requirements of high-voltage and high-frequency applications. Therefore, in this embodiment, the optocoupler isolation drive circuit module 300 is disposed on the first substrate 100, and the power circuit module 400 is disposed on the second substrate 200. This allows the components in the optocoupler isolation drive circuit module 300 to be electrically connected through the first substrate 100, and the components in the power circuit module 400 to be electrically connected through the second substrate 200. This avoids the use of lead frames within the smart power module, greatly reducing the use of bonding wires and lowering the parasitic capacitance within the smart power module.

[0054] This embodiment integrates the isolation drive circuit into the intelligent power module, thereby meeting the isolation requirements for electrical safety, improving system integration, and reducing overall parasitic inductance. At the same time, by placing the isolation drive circuit on the first substrate 100, the number of leads inside the intelligent power module can be reduced, common-mode interference can be reduced, and the reliability of the intelligent power module can be improved. On this basis, higher voltage and frequency settings can be achieved.

[0055] Further, see Figure 2 The first substrate 100 is a printed circuit board.

[0056] In this embodiment, the first substrate 100 is a PCB (Printed Circuit Board).

[0057] It is understandable that the circuit structure of the optocoupler isolation drive circuit module 300 is relatively complex, and the heat dissipation requirement is relatively low. Therefore, in this embodiment, the first substrate 100 is a PCB, which can reduce the application cost while meeting the requirements of the isolation drive circuit.

[0058] Other components 800 within the optocoupler isolation drive circuit module 300 can be connected to the PCB via solder paste 700 through reflow soldering. The chip can be connected to the PCB via conductive silver paste 710, and then the electrical connection is completed through the copper foil circuit inside the PCB.

[0059] In other embodiments, the type of the first substrate 100 can be specifically set, such as a ceramic PCB.

[0060] Furthermore, the second substrate 200 is a ceramic copper-clad laminate.

[0061] The power circuit module 400 is composed of power switching devices, so it generates a lot of heat in applications. Therefore, the power circuit module 400 has a high requirement for heat dissipation. At the same time, the structure of the power circuit module 400 is relatively simple. Therefore, in this embodiment, the second substrate 200 is made of DBC (Direct Bond Copper) to meet the heat dissipation requirements of the power circuit module 400.

[0062] In specific configurations, the heat dissipation side of the ceramic copper-clad laminate is placed at the bottom edge of the intelligent power module to improve its heat dissipation capacity.

[0063] The power circuit module 400 can be connected to the ceramic copper-clad laminate via reflow soldering using solder paste 700.

[0064] Further, see Figure 3 The optocoupler isolation drive circuit module 300 includes an isolation unit 301 and a signal output unit, and the power circuit module 400 includes a plurality of power devices Q1, with the signal output unit connected one-to-one with each power device Q1; wherein:

[0065] One set of output terminals of the isolation unit 301 is connected to one of the signal output units.

[0066] The isolation unit 301 is used to electrically isolate the drive side that receives external control signals from the power side where the power device Q1 is located, and to send the internal control signal corresponding to the external control signal to the signal output unit.

[0067] The signal output unit is used to send internal control signals to the gate of power device Q1.

[0068] The specific type of power device Q1 can be set based on actual needs. For example, the material of the power device can be silicon-based or silicon carbide-based, and the type of power device can be MOSFET, IGBT, etc.

[0069] The input terminal of isolation unit 301 is connected to an external controller. Isolation unit 301 includes multiple output terminals for different power devices Q1. Each output terminal is connected to the gate of power device Q1 through a signal output unit. That is, the number of signal output units is the same as the number of power devices Q1, and they are connected one-to-one. The number of power devices Q1 can be set according to the circuit requirements of the actual application. For example, for a half-bridge circuit, two power devices Q1 can be set, and correspondingly, isolation unit 301 can include two output terminals and two corresponding signal output units. For a two-phase bridge, four power devices Q1 can be set, and correspondingly, isolation unit 301 can include four output terminals and four corresponding signal output units. For a three-phase bridge, six power devices Q1 can be set, and correspondingly, isolation unit 301 can include six output terminals and six corresponding signal output units.

[0070] The specific type of power device Q1 can be set based on actual needs. In this embodiment and subsequent embodiments, a silicon carbide MOSFET is used as an example for illustration.

[0071] The isolation unit 301 can specifically employ an isolation driver chip. The appropriate isolation driver chip can be selected based on the specific configuration of the power circuit module 400. For example, when the power circuit module 400 is a half-bridge power module, a dual-channel isolation driver chip can be used; when the power circuit module 400 is a full-bridge power module, a four-channel isolation driver chip or two dual-channel isolation driver chips can be used; when the power circuit module 400 is a three-phase bridge power module, a six-channel driver chip, three dual-channel driver chips, or six single-channel driver chips can be used. The isolation driver chip can specifically include multiple processing chips U1.

[0072] The isolation unit 301 receives an external control signal sent by an external controller, such as a high / low level signal, and determines the power device Q1 to which the external control signal is targeted. The isolation unit 301 electrically isolates the drive side receiving the external control signal from the power side where the power device Q1 is located, and determines the power device Q1 to which the external control signal is targeted. It then outputs an internal control signal with the same high / low level as the external control signal to the corresponding signal output unit. The signal output unit sends the internal control signal to the gate of the corresponding power device Q1 so that the power device Q1 sets its switching state based on the gate level.

[0073] Further, see Figure 4 The isolation unit includes a processing chip U1 and an optical coupler subunit; the optical coupler subunit includes multiple optical coupler components, and the output terminal of the optical coupler components serves as the output terminal of the isolation unit;

[0074] The output terminals of the processing chip U1 are connected one-to-one with the control terminals of the optocoupler assembly; wherein:

[0075] The processing chip U1 is used to receive external control signals and control the conduction state of the corresponding optocoupler subunit according to the external control signals, so that the optocoupler subunit outputs the corresponding internal control signal.

[0076] The optocoupler components are connected one-to-one with the gate of the power device Q1.

[0077] The processing chip U1 receives the external control signal sent by the external controller and determines the power device Q1 to which the external control signal is targeted, and then determines the optocoupler component corresponding to the power device Q1; the processing chip U1 sends a switching signal to the corresponding optocoupler component, so that the corresponding optocoupler component sends the internal control signal to the gate of the corresponding power device Q1; thus achieving electrical isolation.

[0078] Further, see Figure 5 The optocoupler assembly includes a molding compound 331, a reflective layer 332, a transparent material, a light-emitting diode (LED), and a photosensitive driver chip U2; wherein:

[0079] The encapsulation 331 and the first substrate 100 form a receiving space. The light-emitting diode (LED) and the photosensitive driver chip U2 are disposed on the first substrate 100 within the receiving space. The transparent material fills the receiving space to form a transmissive layer 333, and the reflective layer 332 is disposed between the encapsulation 331 and the transmissive layer 333. The positive terminal of the LED is connected to the output terminal of the processing chip, and the negative terminal of the LED is grounded. The output terminal of the photosensitive driver chip serves as the output terminal of the optocoupler assembly.

[0080] The negative terminal of the LED is grounded, and the positive terminal of the LED is connected to one of the output terminals of the processing chip U1; the positive terminals of different LEDs are connected to the output terminals of the processing chip U1 in a one-to-one correspondence.

[0081] The processing chip U1 receives the external control signal sent by the external controller and determines the power device Q1 to which the external control signal is targeted, and then determines the light-emitting diode (LED) corresponding to the power device Q1; it sends a high-level signal to the positive terminal of the corresponding LED, so that the LED is forward-biased and emits light; the light emitted by the LED is reflected by the reflective layer 332 to the photosensitive driver chip U2, and the photosensitive driver chip U2 outputs a high-level signal to the gate of the corresponding power device Q1 after sensing the light.

[0082] In terms of specific configuration, the light-emitting diode (LED) is electrically connected to the first substrate 100 via solder balls 334. When it receives a switching signal from the input processing chip U1, it emits infrared light. The infrared light passes through the transmission layer 333 and the reflection layer 332 to directly irradiate the photosensitive driver chip U2 or is reflected by the reflection layer 332. That is, the LED converts the electrical signal into an optical signal, and the light is converted back into an electrical signal through the photoelectric effect of the semiconductor, thereby turning on the subsequent drive output circuit.

[0083] The reflective layer 332 is made of resin material, and reflective particles for reflecting infrared light can be filled into the reflective layer 332 to improve the overall reflectivity.

[0084] The entire isolation structure is encapsulated by injection molding using an opaque molding compound 331, which can be made of epoxy resin. While providing electrical and moisture isolation, the molding compound 331, as an opaque material, also isolates the optical couplers of different channels from each other to prevent signal interference between channels.

[0085] The packaging form of the processing chip U1, the light-emitting diode (LED), and the first substrate can be set according to actual needs; for example, depending on the different chips being packaged, flip-chip packaging or on-board chip packaging can be selected.

[0086] Furthermore, the two electrodes of the light-emitting diode (LED) are disposed on the same surface; the positive electrode of the LED is connected to the output terminal of the processing chip U1 through the internal circuit of the first substrate 100, and the negative electrode of the LED is grounded through the internal circuit of the first substrate 100.

[0087] See Figure 5 For flip-chip packaging, the LED chip leads are led out to the chip surface and then connected to the first substrate via solder balls 334. The LEDs are then connected to the processing chip U1 and ground via the internal circuitry of the first substrate 100. It is understood that in this embodiment, the LED leads can be directly connected to the first substrate 100, thus eliminating the need for bonding wires and further reducing the impact of parasitic inductance.

[0088] Similarly, the pins of the photosensitive driver chip can be arranged on the same side, so all pins can be electrically connected to the outside through the internal circuit of the first substrate 100 without the need for bonding wires.

[0089] Furthermore, the two electrodes of the light-emitting diode (LED) are disposed on opposite sides; the first electrode of the LED is connected to the outside through the internal circuit of the first substrate 100; the second electrode of the LED is connected to the corresponding pad on the first substrate 100 through a bonding wire, and the pad is connected to the outside through the internal circuit of the first substrate 100.

[0090] When the first pole is positive, the second pole is negative; when the first pole is negative, the second pole is positive.

[0091] See Figure 6 Regarding the chip packaging method on the board, it is for chips with electrodes on both the back and the front. The back is connected to the first substrate 100 via pads and solder paste, while the surface electrodes are connected to the pads reserved on the first substrate 100 via wire bonding. Generally speaking, using bonding wires 600 will increase parasitic inductance at high frequencies; therefore, flip-chip packaging can be preferred to reduce parasitic inductance. However, for certain specific signal chips, whose pins are located on both sides, electrical connection can be achieved by using bonding wires 600 in this embodiment.

[0092] Similarly, when the pins of the photosensitive driver chip U2 are set on both sides, it can be connected to the external circuit through the bonding wire 600.

[0093] Further, see Figure 4 The isolation unit 301 includes a set of output terminals, one of which is a signal output terminal; the signal output unit includes a first resistor R1; wherein:

[0094] The first resistor R1 is connected between the signal output terminal of the isolation unit 301 and the gate of the power device Q1.

[0095] When the isolation unit 301 outputs a high-level internal control signal, the internal control signal reaches the gate of the power device Q1 through the first resistor R1, and the gate of the power device Q1 presents a high level.

[0096] When the isolation unit 301 outputs a low-level internal control signal, the internal control signal reaches the gate of the power device Q1 through the first resistor R1, and the gate of the power device Q1 presents a low level.

[0097] Furthermore, the signal output unit also includes a second resistor R2 and a first diode D1; wherein:

[0098] The negative terminal of the first diode D1 is connected to the signal output terminal of the isolation unit 301, the positive terminal of the first diode D1 is connected to the first terminal of the second resistor R2, and the second terminal of the second resistor R2 is connected to the gate of the power device Q1.

[0099] It is understandable that in practical applications, due to circuit interference and other issues, the power device Q1 will oscillate when switching. Therefore, in order to avoid the oscillation from affecting the system operation, this embodiment sets up an oscillation suppression and current limiting circuit composed of the second resistor R2 and the first diode D1, thereby suppressing the oscillation of the power device Q1 when switching.

[0100] Further, the isolation unit 301 includes an upper transistor output terminal, which includes an upper transistor high-voltage terminal and an upper transistor ground terminal; the signal output unit includes a negative voltage driving subunit, which includes a first capacitor C1, a second capacitor C2, a first Zener diode DZ1, and a third resistor R3; wherein:

[0101] The positive terminal of the Zener diode DZ1 is connected to the ground terminal of the isolation unit 301, the negative terminal of the Zener diode DZ1 is connected to the source terminal of the power device Q1, the negative terminal of the Zener diode DZ1 is also connected to the first terminal of the third resistor R3, the second terminal of the third resistor R3 is connected to the high voltage terminal of the isolation unit 301, the first capacitor C1 is connected in parallel with the third resistor R3, and the second capacitor C2 is connected in parallel with the Zener diode DZ1.

[0102] In practical applications, due to circuit interference and other issues, the power device Q1 will oscillate when switching. Therefore, in order to avoid the oscillation from affecting the system operation, this embodiment is provided with a negative voltage drive subunit consisting of a first capacitor C1, a second capacitor C2, a first Zener diode DZ1 and a third resistor R3.

[0103] Specifically, after the high-voltage terminal of the isolation unit 301 outputs voltage, the second capacitor C2 is charged through the third resistor R3. After the voltage of the second capacitor C2 reaches the reverse breakdown voltage of the first Zener diode DZ1, the voltage across the first Zener diode DZ1 stabilizes. At this time, a stable negative voltage is provided to the source of the power device Q1.

[0104] By using a negative voltage drive subunit to improve the reliability of power device Q1 turn-off, the switching speed can be increased, switching losses reduced, parasitic oscillations suppressed, and system stability and reliability improved.

[0105] Further, the isolation unit 301 includes an upper transistor output terminal, which includes an upper transistor high-voltage terminal and an upper transistor ground terminal; the optocoupler isolation drive circuit module 300 also includes a bootstrap unit, which includes a fourth resistor R4, a second diode D2, and a third capacitor C3; wherein:

[0106] The first end of the fourth resistor R4 is connected to the driving power supply, the second end of the fourth resistor R4 is connected to the positive terminal of the second diode D2, the negative terminal of the second diode D2 is connected to the high voltage terminal of the upper tube of the isolation unit 301, the first end of the third capacitor C3 is connected to the high voltage terminal of the upper tube of the isolation unit 301, and the second end of the third capacitor C3 is connected to the ground terminal of the upper tube of the isolation unit 301.

[0107] It is understandable that, for the upper transistor of the power switching circuit, after it is turned on, the power supply voltage reaches the source of the power device Q1. At this time, if the gate voltage receives the voltage of the internal control signal and is consistent with the power supply voltage, the gate voltage of the power device Q1 will be consistent with the source voltage, and the power device Q1 will be turned off immediately after being turned on, and cannot maintain the conducting state. Therefore, in order to maintain the conduction of the power device Q1, this embodiment sets up a bootstrap unit composed of the fourth resistor R4, the second diode D2 and the third capacitor C3. The bootstrap unit increases the gate voltage so that after the power device Q1 is turned on, the gate voltage can be guaranteed to be greater than the source voltage, thereby maintaining the conduction of the power device Q1.

[0108] Further, see Figure 2 The intelligent power module further includes a lead frame 500; wherein:

[0109] The lead frame 500 is electrically connected to the first substrate 100, the second substrate 200, and the power circuit module 400, respectively, and is used to lead out the electrodes on the first substrate 100, the second substrate 200, and the power circuit module 400 to the corresponding pins.

[0110] In this embodiment, the internal and external components of the smart power module are connected through the lead frame 500.

[0111] It is understandable that the lead frame 500 here is used for the connection between the internal devices and external pins of the smart power module, rather than for the electrical connection between internal devices. Therefore, the use of the lead frame 500 here will not increase the parasitic capacitance in the smart power module.

[0112] Specifically, the lead frame 500 can be connected to the first substrate 100 and the second substrate 200 respectively through a reflow soldering process using solder paste 700.

[0113] Furthermore, the first substrate 100 is connected to the power circuit module 400 via bonding wire 600.

[0114] For ease of implementation, in this embodiment, the first substrate 100 and the points that need to be connected in the power circuit module 400 are connected by bonding wires 600, thereby realizing the connection between the optocoupler isolation drive circuit module 300 and the power circuit module 400.

[0115] The overall manufacturing process of the intelligent power module is described below:

[0116] (1) Dicing: The required chips, such as power devices Q1, diodes, Zener diodes DZ1, LEDs, photosensitive driver output chips, etc., are cut from the wafer for use in subsequent chip assembly processes.

[0117] (2) Core assembly; First, apply solder paste 700 to the positions where soldering is required using screen printing technology on the PCB substrate and DBC substrate; Place the chip, LED, other components 800 (such as resistors and capacitors), and lead frame 500 to the corresponding positions on the DBC substrate and PCB substrate respectively; Then, assemble and bond the DBC substrate, PCB substrate, and lead frame 500 together at the reserved solder paste positions using a fixture.

[0118] (3) Reflow soldering: The assembled structure is reflow soldered so that the solder paste 700 completes the connection of the lead frame 500, DBC substrate, LED, PCB substrate, chip and other components 800.

[0119] (4) Core mounting: Apply adhesive to the corresponding position on the PCB substrate, place the isolation driver chip in the corresponding position on the PCB substrate, and then cure it.

[0120] (5) Apply adhesive to the locations of the LED and the photosensitive driver chip U2. Transparent insulating materials, such as epoxy resin, can be used.

[0121] (6) Low-temperature curing: Curing the applied transparent epoxy resin.

[0122] (7) Coating: Apply a highly reflective epoxy resin to the surface of the cured transparent resin.

[0123] (8) Curing: Curing the highly reflective epoxy resin to form a reflective layer 332.

[0124] (9) Wire bonding; For power device Q1, aluminum wire is used to connect the electrodes on its surface to the lead frame 500 to lead out to the corresponding pins; For the parts of other components 800 that need to be bonded, gold wire is used to bond to the PCB board.

[0125] (10) Molding; The assembled body that has been bonded above is placed in a molding mold and injection molded with epoxy resin molding compound to form a molding body 331, and then subjected to a post-curing process to ensure that the cross-linking reaction is complete.

[0126] (11) Electroplating and cutting: The outer pin portion of the lead frame 500 is tin-plated to improve solderability, and then the lead frame 500 is cut apart from the part required by the smart power module by stamping process to form a dual in-line package.

[0127] (12) Testing and marking: After passing the electrical performance test, the product information is marked by laser marking to obtain the final intelligent power module.

[0128] See Figure 7 The overall principle of the intelligent power module is explained below:

[0129] The signal input of the external controller is a high-level / low-level signal issued by the control chip, i.e., an external control signal. The optocoupler isolation drive circuit module 300 is an isolation drive chip within the intelligent power module package. The optocoupler isolation drive circuit module 300 receives and processes the externally input external control signal, as well as the voltage feedback (such as bootstrapping) from other components 800. Other components 800, together with the isolated drive chip, form a complete drive circuit on the PCB substrate, and convert the switching signal into an optical signal, which is sent to the photosensitive drive chip U2. The photosensitive drive chip U2 receives the optical signal and converts it into its own switching signal. After passing the voltage signal of the drive power supply and the internal control signal through circuit structures such as undervoltage protection, it is transmitted to the power device chip (equipped with a power device Q1) through a negative voltage drive circuit composed of other components, thereby controlling the switching state of the power device chip. The power device chip, through the change of the switching state, ultimately outputs power to the outside, i.e., realizes the high-voltage current drive function.

[0130] See Figure 4 The driving principle of the intelligent power module will be explained below:

[0131] The power supply VDD supplies power to the isolation driver chip, and the third capacitor C3 and the fourth capacitor C4 provide filtering for the power supply to the isolation driver chip. The third capacitor C3 and the fourth capacitor C4 can be integrated into the intelligent power module; or one of them can be placed in an external computer circuit, but this will reduce the filtering effect.

[0132] The input signals INPUT[0:3] represent external control signals sent from an external controller.

[0133] When the input signal INPUT[0:3] combination indicates that the power device Q1 is turned on, the isolation driver chip determines the output terminal corresponding to the power device Q1 that needs to be turned on, and outputs the internal control signal to the gate of the power device Q1 through the output terminal to realize the driving of the power device Q1; at the same time, the circuit driving function is optimized by bootstrapping, negative voltage driving, etc.

[0134] The specific packaging structure of the intelligent power module is described below:

[0135] See Figure 8 The packaging structure can be roughly divided into three parts:

[0136] 1. The input section, consisting of an isolated driver chip and a bootstrap circuit connected to an external controller; the driver circuit section, consisting of various surface-mount capacitors and resistors;

[0137] 2. The driving circuit section composed of various surface-mount capacitors and resistors;

[0138] 3. The output section consists of power device chips and their output circuits.

[0139] The input section forms the electrical isolation structure of the intelligent power module. The isolation driver chip is soldered onto the PCB board, and external control signals are input through the lead frame 500 above it. The power supply and bootstrap of the driver side in the isolation driver chip are also input from above. To ensure the isolation effect, a safe creepage distance is maintained between the power supply input and signal input pins.

[0140] The driving circuit is bonded to the gate and source of the power device Q1. The gate serves as the driver, while the source provides a voltage reference for the negative voltage drive.

[0141] The final output section outputs the power signal through a half-bridge circuit composed of MOSFETs. The thickness and quantity of the bonding wire 600 need to be considered based on the actual application.

[0142] In this utility model, the terms "first", "second", "third", "fourth" and "fifth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0143] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0144] Although embodiments of the present invention have been shown and described above, the scope of protection of the present invention is not limited thereto. It is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, and substitutions to the above embodiments within the scope of the present invention, and such changes, modifications, and substitutions should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the scope of the claims.

Claims

1. A smart power module, characterized in that, The intelligent power module includes a first substrate, a second substrate, an optocoupler isolation driving circuit module, and a power circuit module; the optocoupler isolation driving circuit module is disposed on the first substrate, the power circuit module is disposed on the second substrate, and the first substrate and the power circuit module are electrically connected. in; The optocoupler-isolated drive circuit module is used to receive external control signals, and after optocoupler isolation between the drive side receiving the external control signals and the power side where the power circuit module is located, send the internal control signals corresponding to the external control signals to the power circuit module.

2. The intelligent power module as described in claim 1, characterized in that, The first substrate is a printed circuit board, and the second substrate is a ceramic copper-clad laminate.

3. The intelligent power module as described in claim 1, characterized in that, The optocoupler isolation driving circuit module includes an isolation unit and a signal output unit, and the power circuit module includes multiple power devices, with the signal output unit connected to each power device in a one-to-one correspondence; wherein: One set of output terminals of the isolation unit is connected to one of the signal output units.

4. The intelligent power module as described in claim 3, characterized in that, The isolation unit includes a processing chip and an optical coupler subunit; the optical coupler subunit includes multiple optical coupler components, and the output terminal of the optical coupler components serves as the output terminal of the isolation unit. The output terminals of the processing chip are connected one-to-one with the control terminals of the optocoupler assembly; wherein: The processing chip is used to receive external control signals and control the conduction state of the corresponding optocoupler subunit according to the external control signals, so that the optocoupler subunit outputs the corresponding internal control signal.

5. The intelligent power module as described in claim 4, characterized in that, The optocoupler assembly includes a molding compound, a reflective layer, a transparent material, a light-emitting diode, and a photosensitive driver chip; wherein: The encapsulation and the first substrate form a receiving space. The light-emitting diode and the photosensitive driving chip are disposed on the first substrate within the receiving space. The transparent material fills the receiving space to form a transmissive layer. The reflective layer is disposed between the encapsulation and the transmissive layer. The positive terminal of the light-emitting diode is connected to the output terminal of the processing chip, and the negative terminal of the light-emitting diode is grounded. The output terminal of the photosensitive driving chip serves as the output terminal of the optocoupler assembly.

6. The intelligent power module as described in claim 5, characterized in that, The two electrodes of the light-emitting diode are disposed on the same side; the positive electrode of the light-emitting diode is connected to the output terminal of the processing chip through the internal circuit of the first substrate, and the negative electrode of the light-emitting diode is grounded through the internal circuit of the first substrate.

7. The intelligent power module as described in claim 5, characterized in that, The two electrodes of the light-emitting diode are disposed on opposite sides; the first electrode of the light-emitting diode is connected to the outside through the internal circuit of the first substrate; the second electrode of the light-emitting diode is connected to the corresponding pad on the first substrate through a bonding wire, and the pad is connected to the outside through the internal circuit of the first substrate.

8. The intelligent power module as described in claim 3, characterized in that, The isolation unit includes an upper transistor output terminal, which includes a high-voltage terminal and a ground terminal; the signal output unit includes a negative voltage drive subunit, which includes a first capacitor, a second capacitor, a first Zener diode, and a third resistor; wherein: The positive terminal of the Zener diode is connected to the ground terminal of the isolation unit, the negative terminal of the Zener diode is connected to the source terminal of the power device, the negative terminal of the Zener diode is also connected to the first terminal of the third resistor, the second terminal of the third resistor is connected to the high-voltage terminal of the isolation unit, the first capacitor is connected in parallel with the third resistor, and the second capacitor is connected in parallel with the Zener diode.

9. The intelligent power module as described in claim 3, characterized in that, The isolation unit includes an upper transistor output terminal, which includes a high-voltage terminal and a ground terminal; the optocoupler isolation drive circuit module further includes a bootstrap unit, which includes a fourth resistor, a second diode, and a third capacitor; wherein: The first end of the fourth resistor is connected to the driving power supply, the second end of the fourth resistor is connected to the positive terminal of the second diode, the negative terminal of the second diode is connected to the high voltage terminal of the upper tube of the isolation unit, the first end of the third capacitor is connected to the high voltage terminal of the upper tube of the isolation unit, and the second end of the third capacitor is connected to the ground terminal of the upper tube of the isolation unit.

10. The intelligent power module as described in claim 1, characterized in that, The intelligent power module further includes a lead frame; wherein: The lead frame is electrically connected to the first substrate, the second substrate, and the power circuit module, respectively, and is used to lead out the electrodes on the first substrate, the second substrate, and the power circuit module to the corresponding pins.

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