Power module structure with integrated current sensor

Abstract

The application discloses a power module structure integrated with a current sensor, and the structure comprises a radiator, a plastic shell, a copper-clad ceramic substrate, a wafer, a cover plate and an AC busbar, the copper-clad ceramic substrate is arranged on the surface of the radiator, the wafer is arranged on the copper-clad ceramic substrate to form a control circuit, the plastic shell is arranged on the radiator and covers the copper-clad ceramic substrate, the AC busbar is connected with the copper-clad ceramic substrate and extends out of the plastic shell, and the cover plate is arranged on the top surface of the plastic shell, the structure further comprises a current sensing chip, a current sensing plate and a metal shielding cover, the current sensing chip is welded to the current sensing plate, the current sensing plate is arranged on the plastic shell and faces the AC busbar extending out of the plastic shell, the metal shielding cover wraps the AC busbar and the current sensing plate, and the current sensing chip detects a current signal of the AC busbar. The structure improves the integration of the power module and the current sensor, avoids the collected current signal from being interfered or interfering other signals, improves current sampling precision and sampling reliability, ensures the power density of the power module and reduces the cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power semiconductor, in particular to a power module structure integrated with current sensor. BACKGROUND

[0002] Power module is a wafer packaged into a whole according to certain functions, which has the advantages of small size and high power density, and is widely used in the field of new energy vehicles. With the development of high power and long endurance of new energy vehicles, the application environment of power module is increasingly harsh, and the integration of power module has attracted widespread attention.

[0003] As shown in Figure 1 , the current sensor output signal is usually connected to the control board, and the current signal flowing through the AC busbar is detected. When the current sensor detects the current of the AC busbar, according to formula (1),

[0004] (1)

[0005] Where B is the magnetic field passing through the current sensor, K is the coefficient, I is the current of the AC busbar, W1 is the width of the AC busbar, and h is the distance between the AC busbar and the current sensor.

[0006] It can be seen that the magnetic field B passing through the current sensor is largely dependent on the width W1 of the AC busbar and the distance h between the AC busbar and the current sensor. In the actual manufacturing process, when the current sensor is installed on the AC busbar, if the distance h between the two components deviates, the measurement error of the current will become larger. In addition, when this structure is applied in a place with strong vibration such as a new energy vehicle, the distance h is easily changed due to the vibration, so the measurement error of the current value will also become larger.

[0007] As shown in Figure 2 and Figure 3As shown, in the conventional new energy vehicle inverter, a current sensor 6 is usually used to detect the current value of the AC busbar 4 in the three-phase AC controller, the conventional power module is composed of a radiator 1, a plastic shell 2, a copper clad ceramic substrate 7 and a wafer 8, the copper clad ceramic substrate 7 is arranged on the surface of the radiator 1, the wafer 8 is arranged on the copper clad ceramic substrate 7 to form a control circuit, the plastic shell 2 is arranged on the radiator 1 and covers the copper clad ceramic substrate 7, the AC busbar 4 is connected to the copper clad ceramic substrate 7, and the control panel 3 of the controller is located on the top surface of the plastic shell 2, since the power module and the current sensor 6 are two independent parts, the detection signal of the current sensor 6 needs to be transmitted to the control panel 3, and generally, a signal line is used to transmit the detection signal to the control panel 3, wherein the current sensor 6 needs to be fixedly installed, and the AC busbar 4 needs to pass through the current sensor 6, therefore, the controller needs to reserve a part of space to install and fix the current sensor 6, and since the current signal is transmitted in the form of a signal line, the current signal is easily disturbed by the external environment or disturbs other signals, and is affected by the vibration of the vehicle driving, the relative displacement between the current sensor 6 and the AC busbar 4 occurs, and the reliability of the new energy vehicle inverter is reduced. At present, the new energy vehicle driving controller requires higher and higher power density and lower and lower cost, and the previous independent arrangement mode of the power module and the current sensor cannot meet the application of the vehicle driving power module. SUMMARY

[0008] The technical problem to be solved by the present application is to provide a power module structure integrated with a current sensor, which overcomes the defects of the conventional power module, improves the integration of the power module and the current sensor, avoids the interference of the collected current signal or the interference of other signals, improves the sampling accuracy and reliability of the current, ensures the power density of the power module and reduces the cost.

[0009] To solve the above technical problems, the power module structure integrated with a current sensor of the present application comprises a radiator, a plastic shell, a copper clad ceramic substrate, a wafer, a cover plate and an AC busbar, the copper clad ceramic substrate is arranged on the surface of the radiator, the wafer is arranged on the copper clad ceramic substrate to form a control circuit, the plastic shell is arranged on the radiator and covers the copper clad ceramic substrate, the AC busbar is connected to the copper clad ceramic substrate and extends out of the plastic shell, the cover plate is arranged on the top surface of the plastic shell, the structure further comprises a current sensing chip, a current sensing plate and a metal shielding cover, the current sensing chip is welded to the current sensing plate, the current sensing plate is arranged on the plastic shell and faces the AC busbar extending out of the plastic shell, the metal shielding cover wraps the AC busbar and the current sensing plate, and the current sensing chip detects the current signal of the AC busbar.

[0010] Further, the structure further comprises a driving control board, a driving signal pin needle and a current signal connector pin needle, the driving control board is arranged on the top surface of the cover plate, the driving signal pin needle is arranged on the driving control board and extends to connect the control circuit composed of the wafer and the copper clad ceramic substrate, the current signal connector pin needle connects the current sensing plate and the driving control board, and the driving signal pin needle and the current signal connector pin needle have the same height.

[0011] Further, the current signal connector pin needle and the driving control board are connected through welding or crimping.

[0012] Further, the metal shielding cover is a C-shaped cover shell, and the height of the open end is lower than that of the driving control board and higher than that of the current sensing chip.

[0013] Further, the metal shielding cover is a C-shaped cover shell formed by twice bending of a metal flat plate, the opening width of the C-shaped cover shell is greater than the width of the AC busbar, and the open end is used to arrange the current signal connector pin needle extending to the driving control board.

[0014] Further, the plastic shell is provided with a buckle at the extension part of the AC busbar, the current sensing plate is arranged on the plastic shell through the buckle or adhesion, and is located between the AC busbar and the driving control board.

[0015] Further, the plastic shell is formed by resin injection molding, the AC busbar is integrally formed with the plastic shell through injection molding, the metal shielding cover is integrally formed with the plastic shell through injection molding or is fixed on the plastic shell by using adhesive.

[0016] Further, the magnetic permeability of the metal shielding cover is greater than or equal to 1000.

[0017] Further, the cross-sectional area of the AC busbar in the metal shielding cover is greater than or equal to 5mm², the AC busbar is ultrasonic welded on the copper clad ceramic substrate, the distance between the position where the AC busbar is welded on the copper clad ceramic substrate and the position of the current sensing chip is less than or equal to 20mm, and the current flowing through the AC busbar is 300-1000A.

[0018] Another power module structure integrated with current sensor, comprising a heat sink, a plastic shell, a copper clad ceramic substrate, a wafer, a cover plate and an AC busbar, the copper clad ceramic substrate is arranged on the surface of the heat sink, the wafer is arranged on the copper clad ceramic substrate to form a control circuit, the plastic shell is arranged on the heat sink and covers the copper clad ceramic substrate, the AC busbar is connected to the copper clad ceramic substrate and extends out of the plastic shell, and the cover plate is arranged on the top surface of the plastic shell, characterized in that: further comprising a current sensing chip, a drive control board and a metal shield, the drive control board is arranged on the top surface of the cover plate, the current sensing chip is welded to the drive control board and faces the AC busbar extending out of the plastic shell, and the metal shield wraps the AC busbar and the current sensing chip and has an open end extending out of the drive control board, and the current sensing chip detects the current signal of the AC busbar.

[0019] The power module structure integrated with current sensor of the present application adopts the above technical scheme, that is, the structure comprises a heat sink, a plastic shell, a copper clad ceramic substrate, a wafer, a cover plate and an AC busbar, the copper clad ceramic substrate is arranged on the surface of the heat sink, the wafer is arranged on the copper clad ceramic substrate to form a control circuit, the plastic shell is arranged on the heat sink and covers the copper clad ceramic substrate, the AC busbar is connected to the copper clad ceramic substrate and extends out of the plastic shell, and the cover plate is arranged on the top surface of the plastic shell, the structure further comprises a current sensing chip, a current sensing board and a metal shield, the current sensing chip is welded to the current sensing board, the current sensing board is arranged on the plastic shell and faces the AC busbar extending out of the plastic shell, the metal shield wraps the AC busbar and the current sensing board, and the current sensing chip detects the current signal of the AC busbar. The structure overcomes the defects of traditional power modules, improves the integration of power modules and current sensors, avoids interference of collected current signals or interference with other signals, improves the sampling accuracy and reliability of the current, ensures the power density of the power module and reduces the cost. BRIEF DESCRIPTION OF DRAWINGS

[0020] The present application will be further described in detail below in combination with the drawings and embodiments:

[0021] Figure 1 Principle diagram for current sensor detecting AC busbar current;

[0022] Figure 2 Traditional power module structure diagram;

[0023] Figure 3 A-A direction diagram in Figure 2 .

[0024] Figure 4 Power module structure integrated with current sensor of the present application diagram;

[0025] Figure 5 Top view of Figure 4 .

[0026] Figure 6 for Figure 5 Middle BB direction view;

[0027] Figure 7 for Figure 4 Enlarged schematic diagram of a portion of the unidirectional AC busbar;

[0028] Figure 8 A schematic diagram of a power module with an integrated current sensor and a drive control board.

[0029] Figure 9 This is a schematic diagram of the power module structure of another integrated current sensor according to the present invention;

[0030] Figure 10 for Figure 9 Top view;

[0031] Figure 11 for Figure 10 C-axis view;

[0032] Figure 12 This is a schematic diagram illustrating the principle of the current sensing chip detecting AC busbar current in the power module structure. Detailed Implementation

[0033] Implementation, for example Figures 2 to 7 As shown, the power module structure of the integrated current sensor of the present invention includes a heat sink 1, a plastic shell 2, a copper-clad ceramic substrate 7, a wafer 8, a cover plate 22, and an AC busbar 4. The copper-clad ceramic substrate 7 is disposed on the surface of the heat sink 1, and the wafer 8 is disposed on the copper-clad ceramic substrate 7 to form a control circuit. The plastic shell 2 is disposed on the heat sink 1 and covers the copper-clad ceramic substrate 7. The AC busbar 4 is connected to the copper-clad ceramic substrate 7 and extends out of the plastic shell 2. The cover plate 22 is disposed on the top surface of the plastic shell 2. The structure also includes a current sensing chip 5, a current sensing plate 10, and a metal shield 9. The current sensing chip 5 is soldered to the current sensing plate 10. The current sensing plate 10 is disposed on the plastic shell 2 and faces the AC busbar 4 extending out of the plastic shell 2. The metal shield 9 covers the AC busbar 4 and the current sensing plate 10. The current sensing chip 5 detects the current signal of the AC busbar 4.

[0034] like Figures 4 to 8As shown, preferably, the structure further comprises a driving control board 3, driving signal pin 12 and current signal connector pin 11, the driving control board 3 is arranged on the top surface of the cover plate 22, the driving signal pin 12 is arranged on the driving control board 3 and extends to connect the control circuit composed of the wafer 8 on the copper clad ceramic substrate 7, the current signal connector pin 11 connects the current sensing plate 10 and the driving control board 3, the height of the driving signal pin 12 and the current signal connector pin 11 is consistent.

[0035] Preferably, the current signal connector pin 11 and the driving control board 3 are connected by welding or crimping.

[0036] Preferably, the metal shielding cover 9 is a C-shaped cover, and the height of the open end is lower than the driving control board 3 and higher than the current sensing chip 5.

[0037] Preferably, the metal shielding cover 9 is a C-shaped cover formed by twice bending of a metal flat plate, the opening width is greater than the width of the AC busbar 4, and the open end is used to arrange the current signal connector pin 11 extending to the driving control board 3.

[0038] Preferably, the plastic shell 2 is provided with a buckle 21 at the extension part of the AC busbar 4, the current sensing plate 10 is arranged on the plastic shell 2 by the buckle 21 or adhesion, and is located between the AC busbar 4 and the driving control board 3.

[0039] Preferably, the plastic shell 2 is formed by resin injection molding, the AC busbar 4 is integrally formed with the plastic shell 2 by injection molding, the metal shielding cover 9 is integrally formed with the plastic shell 2 by injection molding or is fixed on the plastic shell 2 by adhesive.

[0040] Preferably, the magnetic permeability of the metal shielding cover 9 is greater than or equal to 1000.

[0041] Preferably, the cross-sectional area of the AC busbar 4 in the metal shielding cover 9 is greater than or equal to 5mm², the AC busbar 4 is ultrasonically welded on the copper clad ceramic substrate 7, the distance between the position of the AC busbar 4 welded on the copper clad ceramic substrate 7 and the position of the current sensing chip 5 is less than or equal to 20mm, and the current flowing through the AC busbar 4 is 300-1000A.

[0042] As shown in the drawings, Figures 2 to 3 and Figures 9 to 11As shown, another integrated current sensor power module structure, which includes a heat sink 1, a plastic shell 2, a copper clad ceramic substrate 7, a wafer 8, a cover plate 22 and an AC busbar 4, the copper clad ceramic substrate 7 is provided on the surface of the heat sink 1, the wafer 8 is provided on the copper clad ceramic substrate 7 to constitute a control circuit, the plastic shell 2 is provided on the heat sink 1 and covers the copper clad ceramic substrate 7, the AC busbar 4 is connected to the copper clad ceramic substrate 7 and extends out of the plastic shell 2, and the cover plate 22 is provided on the top surface of the plastic shell 2. The structure further comprises a current sensing chip 5, a drive control board 3 and a metal shield 9. The drive control board 3 is provided on the top surface of the cover plate 22, the current sensing chip 5 is welded to the drive control board 3 and directly faces the AC busbar 4 extending out of the plastic shell 2, and the metal shield 9 wraps the AC busbar 4 and the current sensing chip 5 and has an open end extending out of the drive control board 3. The current sensing chip 5 detects the current signal of the AC busbar 4.

[0043] The principle of detecting the current of the AC busbar in the power module structure is as shown in Figure 12 As shown, another integrated current sensor power module structure, which includes a heat sink 1, a plastic shell 2, a copper clad ceramic substrate 7, a wafer 8, a cover plate 22 and an AC busbar 4, the copper clad ceramic substrate 7 is provided on the surface of the heat sink 1, the wafer 8 is provided on the copper clad ceramic substrate 7 to constitute a control circuit, the plastic shell 2 is provided on the heat sink 1 and covers the copper clad ceramic substrate 7, the AC busbar 4 is connected to the copper clad ceramic substrate 7 and extends out of the plastic shell 2, and the cover plate 22 is provided on the top surface of the plastic shell 2. The structure further comprises a current sensing chip 5, a drive control board 3 and a metal shield 9. The drive control board 3 is provided on the top surface of the cover plate 22, the current sensing chip 5 is welded to the drive control board 3 and directly faces the AC busbar 4 extending out of the plastic shell 2, and the metal shield 9 wraps the AC busbar 4 and the current sensing chip 5 and has an open end extending out of the drive control board 3. The current sensing chip 5 detects the current signal of the AC busbar 4.

[0044] (2)

[0045] As shown, another integrated current sensor power module structure, which includes a heat sink 1, a plastic shell 2, a copper clad ceramic substrate 7, a wafer 8, a cover plate 22 and an AC busbar 4, the copper clad ceramic substrate 7 is provided on the surface of the heat sink 1, the wafer 8 is provided on the copper clad ceramic substrate 7 to constitute a control circuit, the plastic shell 2 is provided on the heat sink 1 and covers the copper clad ceramic substrate 7, the AC busbar 4 is connected to the copper clad ceramic substrate 7 and extends out of the plastic shell 2, and the cover plate 22 is provided on the top surface of the plastic shell 2. The structure further comprises a current sensing chip 5, a drive control board 3 and a metal shield 9. The drive control board 3 is provided on the top surface of the cover plate 22, the current sensing chip 5 is welded to the drive control board 3 and directly faces the AC busbar 4 extending out of the plastic shell 2, and the metal shield 9 wraps the AC busbar 4 and the current sensing chip 5 and has an open end extending out of the drive control board 3. The current sensing chip 5 detects the current signal of the AC busbar 4. As shown, another integrated current sensor power module structure, which includes a heat sink 1, a plastic shell 2, a copper clad ceramic substrate 7, a wafer 8, a cover plate 22 and an AC busbar 4, the copper clad ceramic substrate 7 is provided on the surface of the heat sink 1, the wafer 8 is provided on the copper clad ceramic substrate 7 to constitute a control circuit, the plastic shell 2 is provided on the heat sink 1 and covers the copper clad ceramic substrate 7, the AC busbar 4 is connected to the copper clad ceramic substrate 7 and extends out of the plastic shell 2, and the cover plate 22 is provided on the top surface of the plastic shell 2. The structure further comprises a current sensing chip 5, a drive control board 3 and a metal shield 9. The drive control board 3 is provided on the top surface of the cover plate 22, the current sensing chip 5 is welded to the drive control board 3 and directly faces the AC busbar 4 extending out of the plastic shell 2, and the metal shield 9 wraps the AC busbar 4 and the current sensing chip 5 and has an open end extending out of the drive control board 3. The current sensing chip 5 detects the current signal of the AC busbar 4.

Claims

1. A power module structure integrating a current sensor, comprising a heat sink, a plastic housing, a copper-clad ceramic substrate, a wafer, a cover plate, and an AC busbar, wherein the copper-clad ceramic substrate is disposed on the surface of the heat sink, the wafer is disposed on the copper-clad ceramic substrate to form a control circuit, the plastic housing is disposed on the heat sink and covers the copper-clad ceramic substrate, the AC busbar is connected to the copper-clad ceramic substrate and extends out of the plastic housing, and the cover plate is disposed on the top surface of the plastic housing, characterized in that: The system also includes a current sensing chip, a current sensing board, and a metal shield. The current sensing chip is soldered to the current sensing board, which is located on the plastic shell and faces the AC busbar extending from the shell. The metal shield encloses the AC busbar and the current sensing board. The current sensing chip detects the current signal of the AC busbar. The structure also includes a drive control board, drive signal pins, and current signal connector pins. The drive control board is located on the top surface of the cover plate. The drive signal pins are located on the drive control board and extend to the control circuit formed by the wafer on the copper-clad ceramic substrate. The current signal connector pins connect the current sensing board and the drive control board, and the drive signal pins and current signal connector pins are at the same height. The plastic shell is made of resin injection molding. The AC busbar is injection molded into the plastic shell. The metal shield is injection molded into the plastic shell, or it is fixed to the plastic shell with adhesive.

2. The power module structure of the integrated current sensor according to claim 1, characterized in that: The current signal connector pins are connected to the drive control board by soldering or crimping.

3. The power module structure of the integrated current sensor according to claim 1 or 2, characterized in that: The metal shield is a C-shaped cover, and the height of the opening end is lower than that of the drive control board but higher than that of the current sensing chip.

4. The power module structure of the integrated current sensor according to claim 3, characterized in that: The metal shield is formed by bending a metal plate twice to create a C-shaped shell. Its opening width is greater than the width of the AC busbar, and the opening end is used to set the current signal connector pins to extend and connect to the drive control board.

5. The power module structure of the integrated current sensor according to claim 3, characterized in that: The plastic housing has a buckle at the AC busbar extension. The current sensing board is attached to the plastic housing by the buckle or by adhesive, and is located between the AC busbar and the drive control board.

6. The power module structure of the integrated current sensor according to claim 1, characterized in that: The magnetic permeability of the metal shield is greater than or equal to 1000.

7. The power module structure of the integrated current sensor according to claim 1, characterized in that: The cross-sectional area of ​​the AC busbar inside the metal shield is greater than or equal to 5 mm². The AC busbar is ultrasonically welded to the copper-clad ceramic substrate. The distance between the position of the AC busbar welded to the copper-clad ceramic substrate and the position of the current sensing chip is less than or equal to 20 mm. The current flowing through the AC busbar is 300 to 1000 A.

8. A power module structure integrating a current sensor, comprising a heat sink, a plastic housing, a copper-clad ceramic substrate, a wafer, a cover plate, and an AC busbar, wherein the copper-clad ceramic substrate is disposed on the surface of the heat sink, the wafer is disposed on the copper-clad ceramic substrate to form a control circuit, the plastic housing is disposed on the heat sink and covers the copper-clad ceramic substrate, the AC busbar is connected to the copper-clad ceramic substrate and extends out of the plastic housing, and the cover plate is disposed on the top surface of the plastic housing, characterized in that: It also includes a current sensing chip, a drive control board, and a metal shield. The drive control board is located on the top surface of the cover plate. The current sensing chip is soldered to the drive control board and faces the AC busbar extending out of the plastic shell. The metal shield covers the AC busbar and the current sensing chip, and its open end extends out of the drive control board. The current sensing chip detects the current signal of the AC busbar. The plastic shell is made of resin injection molding. The AC busbar is injection molded into the plastic shell. The metal shield is injection molded into the plastic shell, or it is fixed to the plastic shell with adhesive.

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