Power module connection structure with integrated current sensor

Abstract

The application discloses a power module connection structure integrated with a current sensor, wherein a copper-clad ceramic substrate is arranged on the surface of a cooling plate, a power module is arranged on the copper-clad ceramic substrate, busbar terminals are connected with the copper-clad ceramic substrate, the connection structure further comprises a current sensor, the busbar terminals comprise a first connecting part connected with the copper-clad ceramic substrate, a second connecting part inserted into a magnetic core of the current sensor and / or arranged with a sensing chip of the current sensor and a third connecting part connected with a motor, the width of the second connecting part is smaller than the widths of the first and third connecting parts, the thickness of the second connecting part is greater than the thicknesses of the first and third connecting parts, or the thicknesses of the second and third connecting parts are greater than the thickness of the first connecting part. The structure overcomes the defects of traditional power modules adopting independent current sensors for current sampling, effectively reduces the heat generated after the width of the busbar is reduced, reduces the volume of the current sensor, reduces the occupied space and equipment cost, and meets the application of small volume and low cost of the vehicle-mounted driving power module.

Description

Technical Field

[0001] This invention relates to the field of power semiconductor technology, and in particular to a power module connection structure for an integrated current sensor. Background Technology

[0002] A power module is a packaged control module composed of power electronic devices arranged in a specific functional combination, used to drive circuit loads. In the motor drive of new energy vehicles, such as... Figure 1 As shown, current sampling in conventional power modules mostly uses an independent current sensor 1, which is connected to the power module 2 via bolts. Figure 2 As shown, the current sensor 1 is composed of a magnetic core 11 or a sensing chip 12. By reducing the width L2 of the current sensor magnetic core 11, the overall miniaturization of the current sensor 1 can be achieved. However, this requires simultaneously reducing the width L1 of the busbar terminal 21 passing through the current sensor magnetic core 11. Once the width of the busbar terminal 21 narrows, the current density flowing through the busbar terminal 21 and the temperature of the busbar terminal 21 will both increase. This will cause excessive heat conduction to the motor and the busbar terminal 21 itself and its surrounding parts to exceed the heat resistance temperature. To solve this problem, heat dissipation must be provided separately for the busbar terminal or the terminal block connected to the busbar terminal. Conventional applications usually add thermal pads, thermal adhesives, or other thermally conductive fillers around the busbar terminal or terminal block. Moreover, this structure is complex to assemble, costly, and occupies a large space. At present, the controllers used in new energy vehicles require increasingly smaller size and lower cost. The current sampling scheme of this power module can no longer meet the application requirements of the vehicle drive power module. Summary of the Invention

[0003] The technical problem this invention aims to solve is to provide a power module connection structure with an integrated current sensor. This structure overcomes the shortcomings of traditional power modules that use independent current sensors for current sampling, effectively reducing heat generation due to the reduced busbar width. High integration shortens the busbar length and reduces the distance between the heat-generating busbar and the cooling plate. The busbar connects the busbar to the copper-clad ceramic substrate of the cooling plate, ensuring that the heat generated by the busbar is quickly dissipated through the copper-clad ceramic substrate and the cooling plate. Furthermore, it reduces the size of the current sensor, lowering space requirements and equipment costs, thus meeting the needs of small-size, low-cost applications for automotive drive power modules.

[0004] To solve the above technical problems, the power module connection structure of the integrated current sensor comprises a cooling plate, a copper-clad ceramic substrate, a power module and a busbar terminal, the copper-clad ceramic substrate is arranged on the surface of the cooling plate, the power module is arranged on the copper-clad ceramic substrate, and the busbar terminal is connected to the copper-clad ceramic substrate, the connection structure further comprises a current sensor, the busbar terminal comprises a first connecting part connected to the copper-clad ceramic substrate, a second connecting part for inserting a current sensor magnetic core and / or arranging a current sensor sensing chip, and a third connecting part connected to a motor, the width of the second connecting part is smaller than the width of the first connecting part and the third connecting part.

[0005] Further, the thickness of the second connecting part is greater than the thickness of the first connecting part and the third connecting part, or the thickness of the second connecting part and the third connecting part is greater than the thickness of the first connecting part, and the boundary line of the thickness change of the second connecting part and the first connecting part is in the middle of the two or in the first connecting part, and the boundary line of the thickness change of the second connecting part and the third connecting part is in the middle of the two or in the third connecting part, wherein the busbar terminal composed of the first connecting part, the second connecting part and the third connecting part can be integrally formed by cold forging or extrusion.

[0006] Further, the second connecting part comprises a first terminal extended from the first connecting part and a second terminal extended from the third connecting part, the first terminal and the second terminal are overlapped and connected by welding or rivets, the current sensor magnetic core is inserted into the overlapped position of the first terminal and the second terminal, and / or the current sensor sensing chip is arranged above the overlapped position of the first terminal and the second terminal.

[0007] Further, the connection structure further comprises a copper bar, the length and width of the copper bar match the length and width of the second connecting part, the copper bar is arranged on the front surface or the back surface of the second connecting part and connected by welding or rivets, the current sensor magnetic core is inserted into the connecting part of the copper bar and the second connecting part, and / or the current sensor sensing chip is arranged above the connecting part of the copper bar and the second connecting part.

[0008] Further, the two side edges of the second connecting part are bent upward or downward, forming the width of the second connecting part smaller than the width of the first connecting part and the third connecting part, the current sensor magnetic core is inserted into the bent part of the second connecting part, and / or the current sensor sensing chip is arranged above the bent part of the second connecting part.

[0009] Further, the second connecting part comprises a second terminal extended from the third connecting part, the second terminal is overlapped on the first connecting part, and the overlapped part is connected by welding or rivets, the current sensor magnetic core is inserted into the second terminal, and / or the current sensor sensing chip is arranged above the second terminal.

[0010] Further, the first connecting part is connected with the copper clad ceramic substrate by brazing.

[0011] Further, the second connecting part is located at any position in the width direction of the busbar terminal.

[0012] Further, the connecting structure further comprises a plastic shell, the second connecting part and the current sensor magnetic core and / or the induction chip are arranged in the plastic shell, and the plastic shell is filled with resin for packaging.

[0013] Since the power module connecting structure integrated with the current sensor of the present application adopts the above technical scheme, that is, the copper clad ceramic substrate is arranged on the surface of the cooling plate, the power module is arranged on the copper clad ceramic substrate, the busbar terminal is connected with the copper clad ceramic substrate, the connecting structure further comprises a current sensor, the busbar terminal comprises a first connecting part connected with the copper clad ceramic substrate, a second connecting part inserted into the current sensor magnetic core and / or arranged with the current sensor induction chip, and a third connecting part connected with the motor, the width of the second connecting part is smaller than the width of the first connecting part and the third connecting part, the thickness of the second connecting part is greater than the thickness of the first connecting part and the third connecting part, or the thickness of the second connecting part and the third connecting part is greater than the thickness of the first connecting part. The structure overcomes the defects of the conventional power module using independent current sensor for current sampling, effectively reduces the heat generated after the width of the busbar is reduced, highly integrates and shortens the length of the busbar, reduces the distance from the heating busbar to the cooling plate, and places the copper clad ceramic substrate on the cooling plate through the busbar connection. The structure ensures that the heat generated by the busbar is quickly dissipated through the copper clad ceramic substrate and the cooling plate, reduces the volume of the current sensor, reduces the occupied space and equipment cost, and meets the application of small size and low cost of the vehicle-mounted driving power module. BRIEF DESCRIPTION OF DRAWINGS

[0014] The present application will be further described in detail below in combination with the drawings and embodiments:

[0015] Figure 1 It is a schematic diagram of the conventional power module current sampling structure;

[0016] Figure 2 It is a schematic diagram of the current sensor for conventional power module current sampling;

[0017] Figure 3 It is a schematic diagram of the power module connecting structure integrated with the current sensor of the present application;

[0018] Figure 4 It is a top view of the connecting structure;

[0019] Figure 4a It is a schematic diagram of the busbar terminal integrated structure in the connecting structure;

[0020] Figure 4b is a side view of the connection structure; Figure 4a

[0021] Figures 5 to 8 is a schematic view of one of the configurations of the second connection part in the connection structure;

[0022] Figures 9 to 11 is a schematic view of the structure of the second connection part provided with a copper bar in the connection structure;

[0023] Figures 12 to 14 is a schematic view of another of the configurations of the second connection part in the connection structure;

[0024] Figures 15 to 17 is a schematic view of a third of the configurations of the second connection part in the connection structure;

[0025] Figure 18 is a schematic view of the position of the second connection part in the connection structure in the width direction of the busbar terminal. DETAILED DESCRIPTION

[0026] The power module connection structure of the integrated current sensor according to the present application is shown in Figure 3 and Figure 4 The power module connection structure of the integrated current sensor according to the present application is shown in

[0027] Preferably, the thickness of the second connection part 6 is greater than the thickness of the first connection part 5 and the third connection part 7, or the thickness of the second connection part 6 and the third connection part 7 is greater than the thickness of the first connection part 5; the boundary line of the change in thickness of the second connection part 6 and the first connection part 5 can be in the middle of the two, or in the first connection part 5, and the boundary line of the change in thickness of the second connection part 6 and the third connection part 7 can be in the middle of the two, or in the third connection part 7; as shown in Figure 4a and Figure 4b Preferably, the first connection part 5, the second connection part 6 and the third connection part 7 of the busbar terminal 21 can be integrally formed by cold forging or extrusion, as shown in

[0028] Preferably, as shown in Figures 5 to 8 ​As shown, the second connecting part 6 includes a first terminal 51 extended from the first connecting part 5 and a second terminal 71 extended from the third connecting part 7, the first terminal 51 and the second terminal 71 are overlapped and connected by welding or rivet, the current sensor magnetic core 11 is inserted into the overlapped position of the first terminal 51 and the second terminal 71, and / or the current sensor induction chip 12 is arranged above the overlapped position of the first terminal 51 and the second terminal 71.

[0029] Preferably, as shown in the figure, the second connecting part 6 is arranged on the left side of the busbar terminal 21 in the width direction, of course, it can also be arranged in the center or on the right side, and the purpose is to avoid interference, such as after the second connecting part 6 is inserted into the current sensor magnetic core, causing the collision of the adjacent current sensor magnetic core, and the misplacement of the second connecting part 6 can effectively solve the interference problem of related parts. Figures 9 to 11 As shown, the connection structure further includes a copper bar 8, the length and width of the copper bar 8 match the length and width of the second connecting part 6, the copper bar 8 is arranged on the front or back surface of the second connecting part 6 and connected by welding or rivet, the current sensor magnetic core 11 is inserted into the connecting position of the copper bar 8 and the second connecting part 6, and / or the current sensor induction chip 12 is arranged above the connecting position of the copper bar 8 and the second connecting part 6.

[0030] Preferably, as shown in the figure, the second connecting part 6 is arranged on the left side of the busbar terminal 21 in the width direction, of course, it can also be arranged in the center or on the right side, and the purpose is to avoid interference, such as after the second connecting part 6 is inserted into the current sensor magnetic core, causing the collision of the adjacent current sensor magnetic core, and the misplacement of the second connecting part 6 can effectively solve the interference problem of related parts. Figures 12 to 14 As shown, the two side edges 61 of the second connecting part 6 are bent upward or downward, forming the second connecting part 6 with a width smaller than the width of the first connecting part 5 and the third connecting part 7, the current sensor magnetic core 11 is inserted into the bent position of the second connecting part 6, and / or the current sensor induction chip 12 is arranged above the bent position of the second connecting part 6.

[0031] Preferably, as shown in the figure, the second connecting part 6 is arranged on the left side of the busbar terminal 21 in the width direction, of course, it can also be arranged in the center or on the right side, and the purpose is to avoid interference, such as after the second connecting part 6 is inserted into the current sensor magnetic core, causing the collision of the adjacent current sensor magnetic core, and the misplacement of the second connecting part 6 can effectively solve the interference problem of related parts. Figures 15 to 17 As shown, the second connecting part 6 includes a second terminal 71 extended from the third connecting part 7, the second terminal 71 is overlapped on the first connecting part 5, and the overlapped position is connected by welding or rivet, the current sensor magnetic core 11 is inserted into the second terminal 71, and / or the current sensor induction chip 12 is arranged above the second terminal 71.

[0032] Preferably, the first connecting part 5 and the copper clad ceramic substrate 4 are connected by brazing.

[0033] Preferably, as shown in the figure, the second connecting part 6 is arranged on the left side of the busbar terminal 21 in the width direction, of course, it can also be arranged in the center or on the right side, and the purpose is to avoid interference, such as after the second connecting part 6 is inserted into the current sensor magnetic core, causing the collision of the adjacent current sensor magnetic core, and the misplacement of the second connecting part 6 can effectively solve the interference problem of related parts. Figure 18 As shown, the second connecting part 6 is located at any position in the width direction of the busbar terminal 21. The figure shows that the second connecting part 6 is located on the left side of the busbar terminal 21 in the width direction, of course, it can also be arranged in the center or on the right side, and the purpose is to avoid interference, such as after the second connecting part 6 is inserted into the current sensor magnetic core, causing the collision of the adjacent current sensor magnetic core, and the misplacement of the second connecting part 6 can effectively solve the interference problem of related parts.

[0034] Preferably, the connecting structure further comprises a plastic shell 9, the second connecting part 6 and the current sensor magnetic core 11 and / or the induction chip 12 are arranged in the plastic shell 9, and the plastic shell 9 is filled with resin for packaging.

[0035] The connecting structure divides the busbar terminal output by the power module into a first connecting part, a second connecting part and a third connecting part, the first connecting part is connected to the power module through the copper clad ceramic substrate, the third connecting part is connected to the motor, the second connecting part integrates the magnetic core and / or the induction chip of the current sensor, and forms a current sampling structure of the power module; and the width of the second connecting part is smaller than that of the first connecting part and the third connecting part, and the second connecting part is overlapped, provided with a copper bar or the two side edges of the originally same width second connecting part are bent to make the thickness of the second connecting part greater than that of the first connecting part and the third connecting part, so that a small current sensor can be arranged, the area through which the current flows is not reduced, the temperature of the busbar terminal due to the reduction of the cross section is avoided, and the stability of the power module, the motor and the surrounding parts is ensured. The current sensor integrated in the second connecting part adopts the magnetic core penetrating through the second connecting part and the induction chip arranged above the second connecting part to collect the current signal of the busbar terminal, or the induction chip can be separately arranged above the second connecting part to collect the current signal of the busbar terminal, and the specific form is determined according to the needs of collecting the current signal of the busbar terminal.

[0036] Meanwhile, the magnetic core and / or the induction chip of the current sensor are packaged in the power module through the plastic shell, the width of the busbar terminal is reduced, the small current sensor is integrated, and the length of the busbar section matched with the current sensor is shortened. Through the design of the busbar lamination and bending, the effective current-carrying area of the busbar terminal is ensured, the resistance of the narrowed part of the busbar terminal does not increase sharply, the busbar terminal is connected to the copper clad ceramic substrate, the copper clad ceramic substrate is connected to the cooling plate, and the heat generated by the busbar terminal can be quickly released to the cooling plate, so that the power module and the surrounding devices can operate within a reasonable temperature range, and the application performance of the power module is improved.

[0037] The connecting structure highly integrates the current sensor in the power module, solves the problems of large size and troublesome assembly of the traditional power module current sampling device, ensures the effective current-carrying area of the busbar terminal through the design of the busbar terminal lamination and bending, and dissipates heat through the copper clad ceramic substrate and the cooling plate, so that the damage of the power module and the surrounding devices caused by the serious heating and poor heat dissipation of the narrowed busbar terminal after integrating the small current sensor is avoided, and the demand of small size and low cost of the controller used in new energy vehicles is met.

Claims

1. An integrated current sensor power module connection structure comprising a cooling plate, a copper clad ceramic substrate, a power module and a bus bar terminal, the copper clad ceramic substrate is provided on the surface of the cooling plate, the power module is provided on the copper clad ceramic substrate, and the bus bar terminal is connected to the copper clad ceramic substrate, characterized in that: The busbar terminal comprises a first connecting part connected with the copper clad ceramic substrate, a second connecting part for inserting a current sensor magnetic core and / or arranging a current sensor sensing chip, and a third connecting part connected with the motor, wherein the width of the second connecting part is smaller than the width of the first and third connecting parts. The second connecting part comprises a first terminal extended from the first connecting part and a second terminal extended from the third connecting part, the first and second terminals are overlapped and connected by welding or rivet, the overlapped position of the first and second terminals is inserted into the current sensor magnetic core, and / or the current sensor sensing chip is arranged above the overlapped position of the first and second terminals. The second connecting part is located at the left side of the busbar terminal width direction or is centered or located at the right side. The connecting structure further comprises a copper bar, the length and width of the copper bar match the length and width of the second connecting part, the copper bar is arranged on the front or back surface of the second connecting part and is connected by welding or rivet, the connecting position of the copper bar and the second connecting part is inserted into the current sensor magnetic core, and / or the current sensor sensing chip is arranged above the connecting position of the copper bar and the second connecting part.

2. The integrated current sensor power module connection structure of claim 1, wherein: The thickness of the second and third connecting parts is greater than the thickness of the first connecting part, and the boundary line of the thickness change of the second connecting part and the first connecting part is in the middle of the two or in the first connecting part, and the boundary line of the thickness change of the second connecting part and the third connecting part is in the middle of the two or in the third connecting part.

3. The power module connection structure of an integrated current sensor according to claim 1 or 2, characterized by: The two side edges of the second connecting part are bent upward or downward, forming the width of the second connecting part smaller than the width of the first and third connecting parts, the bent position of the second connecting part is inserted into the current sensor magnetic core, and / or the current sensor sensing chip is arranged above the bent position of the second connecting part.

4. The power module connection structure of an integrated current sensor according to claim 1 or 2, characterized by: The second connecting part comprises a second terminal extended from the third connecting part, the second terminal is overlapped on the first connecting part, and the overlapped position is connected by welding or rivet, the second terminal is inserted into the current sensor magnetic core, and / or the current sensor sensing chip is arranged above the second terminal.

5. The integrated current sensor power module connection structure of claim 1, wherein: The first connecting part and the copper clad ceramic substrate are connected by brazing.

6. The integrated current sensor power module connection structure of claim 1, wherein: The connecting structure further comprises a plastic shell, the second connecting part and the current sensor magnetic core and / or the sensing chip are arranged in the plastic shell, and the plastic shell is packaged by resin filling.

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