Power module and device

Abstract

The utility model provides a power module and device, which comprises a shell, a terminal assembly and a substrate, the substrate is provided with a plurality of semiconductor chip sets, and the top of each semiconductor chip set is provided with a copper bar, so that the tops of the semiconductor chips in the sets are interconnected to increase the cross sectional area of a current path; the copper bar is connected with a preset position on the substrate; the terminal assemblies are arranged at the two ends of the substrate, the substrate is arranged in the shell, and the terminal assemblies penetrate through the shell; and the substrate is directly connected with the radiator through the shell. The integrated structure is compact, the parasitic resistance is effectively reduced, the through-current capability is improved, the loss is further reduced, and the heat dissipation capability is effectively improved.

Description

Technical Field

[0001] This utility model relates to the technical field of semiconductor power device packaging, and in particular to a power module and device. Background Technology

[0002] Electric motorcycles and low-speed vehicles use low-voltage Si MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) as power switching devices because their motor drive inverters have relatively low power and low battery voltage.

[0003] Currently, the mainstream packaging forms for these devices are TO-263 (surface-mount power semiconductor package) or TOLL (Transistor Outline Leadless) discrete packages. In electric drive systems, multiple discrete devices are typically connected in parallel to increase their current rating. To ensure good heat dissipation, these devices are usually mounted on an aluminum substrate using surface-mount technology, and then the aluminum substrate is mounted on a heat sink. However, for discrete packages, the number of discrete devices connected in parallel is large, and the spacing between them is large. This leads to a complex assembly process and differences in parasitic circuit parameters, causing an imbalance between dynamic and static currents among the discrete devices. Because the individual discrete devices are relatively large, and there are gaps between them when mounted on the aluminum substrate, the overall circuit size is large, resulting in a relatively low power density. The discrete devices can only dissipate heat through the aluminum substrate, which has an insulating layer material with very low thermal conductivity, easily increasing thermal resistance and resulting in relatively poor heat dissipation.

[0004] In addition, some manufacturers have launched low-voltage MOSFET top-heat-dissipated power modules. In these modules, multiple MOSFET chips are connected in parallel and soldered onto a DBC (copper-clad ceramic substrate). The top of the chips is connected to the DBC via aluminum bonding wires, achieving a more compact design. The bottom of the DBC is connected to a heatsink. However, the aluminum bonding wire connection on the top of the MOSFET chips introduces significant parasitic resistance due to the limited number of aluminum wires. Under high current loads, this can lead to substantial losses and excessively high chip junction temperatures. Existing modules use through-hole power terminals directly soldered to the PCB, which can result in significant line losses. It is difficult to dissipate heat through the PCB surface or through the module pins to the DBC and then through the heatsink, leading to excessively high PCB surface temperatures. Utility Model Content

[0005] In view of the shortcomings of the prior art described above, the technical problem to be solved by this utility model is to provide a power module that reduces parasitic resistance, improves current carrying capacity, and at the same time reduces the thermal resistance of semiconductor chip components, thereby effectively increasing the operating current of the power module.

[0006] This utility model provides a power module, including a housing, terminal assembly, and substrate. The substrate is provided with a plurality of semiconductor chip groups, and the top of each semiconductor chip group is provided with at least two copper strips to interconnect the tops of each semiconductor chip in the group, thereby increasing the cross-sectional area of ​​the current path. Each copper strip is connected to a predetermined position on the substrate. The terminal assembly is arranged at both ends of the substrate, the substrate is disposed in the housing, and the terminal assembly passes through the housing.

[0007] Preferably, the copper strip includes a plurality of first connecting units and second connecting units, wherein the first connecting units are disposed on the top of the semiconductor chip through surface contact, and adjacent first connecting units are connected through the second connecting units.

[0008] Preferably, the second connecting unit is connected to the first connecting unit in a direction perpendicular to the substrate.

[0009] Preferably, the root of the second connecting unit is V-shaped.

[0010] Preferably, the top of the housing has a first through hole, and the outer layer of the substrate is engaged in the first through hole and connected to the heat sink.

[0011] Preferably, the terminal assembly is provided with a limiting part for snapping onto the PCB board.

[0012] Preferably, the terminal assembly includes a power terminal connected to the busbar, and the power terminal has a second through hole.

[0013] On the other hand, this utility model also provides a device including the power module as described above.

[0014] Preferably, the power module includes a housing and a substrate, the substrate being disposed inside the housing and directly connected to the heat sink through the housing.

[0015] As described above, the power module and device disclosed in this utility model have the following beneficial effects:

[0016] This invention interconnects the top of semiconductor chips by placing copper strips on the top of the semiconductor chips, making the overall module structure compact, effectively reducing parasitic resistance, increasing current carrying capacity, thereby reducing losses and effectively improving heat dissipation.

[0017] This invention uses copper strips as a heat conduction path, which can effectively reduce the thermal resistance of semiconductor chips and thus increase the operating current of power modules.

[0018] This invention uses copper strips to interconnect semiconductor chips at the top in a direction perpendicular to the substrate, which can effectively reduce the size of the power module and thus improve the power density. Attached Figure Description

[0019] Figure 1 This is a front view of a power module provided in an embodiment of the present invention.

[0020] Figure 2 Left view of a power module provided in an embodiment of this utility model.

[0021] Figure 3 This is a top view of a power module provided in an embodiment of the present invention.

[0022] Figure 4 A bottom view of the internal structure of a power module provided in an embodiment of this utility model.

[0023] Figure 5 A front view of the internal structure of a power module provided in an embodiment of this utility model.

[0024] Figure 6 for Figure 5 Local magnification Figure I .

[0025] Figure 7 A front view of the internal structure of a power module provided in an embodiment of this utility model.

[0026] Figure 8 for Figure 7 Top view.

[0027] Figure 9 A three-dimensional schematic diagram of the internal structure of a power module provided in an embodiment of this utility model.

[0028] Figure 10 This is a circuit diagram of a power module provided in one embodiment of the present invention.

[0029] Figure 11 A simulation diagram of a power module provided in an embodiment of this utility model.

[0030] Figure 12 This is a schematic diagram of the operating conditions of a power module provided in an embodiment of the present invention.

[0031] Explanation of reference numerals in the attached figures:

[0032] 100, Housing; 110, First through hole; 200, Terminal assembly; 210, Limiting part; 220, Power terminal; 221, Second through hole; 230, Pin; 300, Substrate; 400, Semiconductor chipset; 410, Semiconductor chip; 500, Copper strip; 510, First connection unit; 520, Second connection unit; 600, Heat sink; 700, PCB board; 800, AC output copper pillar; 900, DC busbar. Detailed Implementation

[0033] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0034] It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this utility model, should still fall within the scope of the technical content disclosed in this utility model. Furthermore, the terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of implementation of this utility model.

[0035] like Figures 1 to 6As shown, this utility model provides an embodiment of a power module, including a housing 100, a terminal assembly 200, and a substrate 300. A semiconductor chip assembly 400 is soldered onto the conductive layer of the substrate 300. The semiconductor chip assembly 400 is composed of a plurality of semiconductor chips 410 connected in parallel, with the high-side semiconductor chip connected to the positive terminal and the low-side semiconductor chip connected to the negative terminal, forming a half-bridge circuit. The power module can realize energy conversion between the power supply and the load by controlling the conduction and cutoff between the semiconductor chips. The semiconductor chip is preferably a Si MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). To achieve a compact structure, the semiconductor chips in the semiconductor chip assembly can be arranged in an array. At least two copper strips 500 (dark yellow area) are soldered to the top of the semiconductor chip assembly 400. In this embodiment, the number of copper strips 500 is preferably two, which are respectively connected to the high-side semiconductor chip and the low-side semiconductor chip. The copper strip 500 interconnects the tops of the semiconductor chips 410 within the semiconductor chipset, enabling electrical pathways between semiconductor chips and between semiconductor chips and the substrate. This increases the cross-sectional area of ​​the current path, effectively reduces parasitic resistance, and improves the heat dissipation capacity of the semiconductor chips.

[0036] like Figure 4 and Figure 8As shown, the conductive layer (light yellow area) of the substrate 300 includes multiple conductive regions for connecting the terminal assembly 200, specifically including a P region (for connecting to the positive terminal of the DC power supply), an N region (for connecting to the negative terminal of the DC power supply), a D1 region (for connecting to the drain of the high-side semiconductor chip), a G1 region (for connecting to the gate of the high-side semiconductor chip), an S1 region (for connecting to the source of the high-side semiconductor chip), an AC region (for connecting to the AC output terminal), an S2 region (for connecting to the source of the low-side semiconductor chip), a G2 region (for connecting to the gate of the low-side semiconductor chip), and a D2 region (for connecting to the drain of the low-side semiconductor chip). The P region and the D1 region are located in the same area, as are the AC, S1, and D2 regions, and the remaining regions are independent and do not contact each other. A copper strip 500 on the top of the high-side semiconductor chip connects to the AC region, and one end of the copper strip 500 on the top of the low-side semiconductor chip connects to the N region, while the other end connects to the S2 region. The high-side semiconductor chip located in region P is connected to region G1 (blue area) via aluminum bonding wires, and the low-side semiconductor chip located in region AC is connected to region G2 (blue area) via aluminum or copper bonding wires to ensure circuit flow. The substrate 300 is covered by a housing 100, with the outer portion of the substrate 300 exposed. The housing 100 effectively reduces mechanical damage to components on the substrate 300 and prevents dust from entering. It should be noted that the connection of the copper strip 500 to the semiconductor chip 410 and the substrate 300 effectively reduces the length of electrical lines, lowers parasitic inductance, and provides good current distribution performance. Simultaneously, wafer-level binning allows for screening of the electrical characteristics of semiconductor chips to ensure consistency among parallel-connected semiconductor chips and improve assembly efficiency.

[0037] When using, such as Figure 12 As shown, the housing 100 is attached to the heat sink, and the partially exposed substrate 300 is directly connected to the heat sink 600 via a thermal interface material (TIM). This allows the heat generated by the semiconductor chipset 400 to be transferred to the substrate 300 via the copper strip 500. The substrate 300 then transfers the heat to the heat sink, effectively dissipating heat from the semiconductor chipset 400 and avoiding thermal resistance from the intermediate insulating layer. Specifically, as... Figure 11 As shown, the power of a single semiconductor chip is preferably 18W, and the effective current is preferably 354A. A 60s transient thermal simulation of this power module shows that the copper strip 500 can significantly reduce the maximum junction temperature of the semiconductor chip to below 175℃, thus enabling the power module to have strong current-carrying capacity. It should be noted that the substrate 300 is preferably a DBC substrate (Direct Bond Copper), which has good thermal conductivity.

[0038] Furthermore, such as Figure 4 , Figure 8 and Figure 10 As shown, the terminal assembly 200 includes power terminals 220 and pins 230. Power terminals 220 include a P terminal (positive), an N terminal (negative), and an AC terminal (AC output). Pins 230 include a D1 pin (drain of the high-side semiconductor chip), a G1 pin (gate of the high-side semiconductor chip), an S1 pin (source of the high-side semiconductor chip), a D2 pin (drain of the low-side semiconductor chip), an S2 pin (source of the low-side semiconductor chip), and a G2 pin (gate of the low-side semiconductor chip). The D2 pin is integrated with the AC terminal, which is connected to the load. Pins G1 and G2 are soldered to predetermined positions on the PCB board. Figure 4 , Figure 8 and Figure 10 As shown, each terminal and pin is located in its corresponding conductive area, which will not be elaborated further here. It should be noted that in the high-side conduction path, the current flows through the P terminal, through the high-side semiconductor chip to the AC terminal, and then returns to the negative terminal through the load. In the low-side conduction path, the current flows directly from the AC terminal through the low-side semiconductor chip back to the negative terminal. The AC output is generated by controlling the high-side and low-side semiconductor chips via the PCB board.

[0039] Furthermore, limiting portions 210 are provided on the P terminals, N terminals, and pin 230. During assembly, the P terminals and N terminals need to be inserted into predetermined positions on the PCB board to secure them, and then soldered. The structure and connection method of the AC terminals can be determined based on specific operating conditions or customer usage habits. Figure 4 , Figure 8 and Figure 12 As shown, second through holes 221 are provided on the P terminal, N terminal, and AC terminal. These second through holes 221, along with bolts, connect the P and N terminals to the DC busbar 900, and the AC terminal to the AC busbar. This provides a path for high-power current through the busbar, enhancing its current carrying capacity and heat dissipation, thus preventing PCB overheating. The AC terminal can also be connected to the AC output copper pillar 800 to conduct large currents, effectively avoiding overheating caused by high current transmission through the PCB.

[0040] In one embodiment, such as Figure 5 and Figure 6As shown, the copper strip 500 includes several first connecting units 510 and second connecting units 520. The first connecting units 510 and 520 are made of copper. The first connecting unit 510 includes, but is not limited to, a sheet-like structure, designed to allow surface contact between the first unit 510 and the top of the semiconductor chip. The thickness can be determined according to specific operating conditions. The first connecting unit 510 is attached to the top of the semiconductor chip 410 through surface contact, and the connection method between the first unit 510 and the semiconductor chip 410 includes, but is not limited to, bonding with conductive adhesive, and can also be connected by welding or pressing. Preferably, in this embodiment, adjacent first connecting units 510 are connected by multiple second connecting units 520, and the second connecting units 520 are arrayed along the length of the gap between adjacent semiconductor chips; alternatively, the first connecting units 510 and second connecting units 520 are integrally formed. It should be noted that the first connecting unit 510 can increase the cross-sectional area of ​​the current path, effectively reducing parasitic resistance and losses. The first connecting unit 510 and the second connecting unit 520 have both conductive and thermal conductive functions, effectively reducing thermal resistance.

[0041] Furthermore, such as Figure 6 As shown, the second connection unit 520 is connected to the first connection unit 510 along a direction perpendicular to the substrate, and the root of the second connection unit 520 includes, but is not limited to, a V-shaped configuration. It should be noted that, in this embodiment, the root of the second connection unit 520 is preferably a V-shaped structure, with the opening of the V-shaped structure facing the substrate 300 in an inverted state. The two connection portions (not shown in the figure) at the root of the V-shaped structure are respectively fixedly connected to the first connection unit 510 on the top of the adjacent semiconductor chips on both sides. Through the connection of the V-shaped structure, the first connection unit 510 and the second connection unit 520 are arranged in a layered layout along a direction perpendicular to the substrate, effectively reducing the footprint of the first connection unit 510 and the second connection unit 520 on the substrate 300, making the overall structure of the power module more compact, and simultaneously improving the power density of the power module.

[0042] In one embodiment, such as Figure 3 and Figure 12 As shown, a first through-hole 110 is provided on the top of the housing 100. The shape of the first through-hole 110 includes, but is not limited to, a rectangle. The outer layer (i.e., the thermally conductive layer) of the substrate 300 is engaged within the first through-hole 100, so that the outer layer of the substrate 300 can be connected to the heat sink 600 through a thermal interface material (TIM). In use, the heat generated by the semiconductor chip during operation is conducted to the heat sink 600 through the outer layer of the substrate to achieve heat dissipation.

[0043] Furthermore, in a second aspect, this disclosure also provides an apparatus having the power module provided in this disclosure. This apparatus includes, but is not limited to, a motor drive inverter. The power module includes a housing 100 and a substrate 300, with the substrate 300 disposed within the housing 100. The substrate 300 is directly connected to a heat sink 600 via the housing 100. Other components and their connections are detailed above and will not be repeated here.

[0044] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A power module comprising a housing, a terminal assembly and a substrate, characterized in that, The substrate is provided with a semiconductor chip set, the top of the semiconductor chip set is provided with at least two copper strips, the top of each semiconductor chip in the set is interconnected; each copper strip is connected with a predetermined position on the substrate; the terminal assembly is arranged at both ends of the substrate, the substrate is arranged in the shell, and the terminal assembly penetrates the shell.

2. The power module of claim 1, wherein, The copper strip comprises a plurality of first connection units and second connection units, the first connection unit is arranged on the top of the semiconductor chip through surface contact, and the corresponding first connection units are connected through the second connection units.

3. The power module of claim 2, wherein, The second connection unit connects the first connection unit along the direction perpendicular to the substrate.

4. The power module of claim 3, wherein, The root of the second connection unit is arranged in a V shape.

5. The power module of claim 1, wherein, The top of the shell is provided with a first through hole, and the outer layer of the substrate is clamped in the first through hole for connecting with a heat sink.

6. The power module of claim 1, wherein, The terminal assembly is provided with a limiting part for clamping a PCB.

7. The power module of claim 6, wherein, The terminal assembly comprises a power terminal connected with a direct current busbar and a power terminal connected with an alternating current busbar or an alternating current output copper column; the power terminal is provided with a second through hole.

8. An apparatus, comprising: The power module comprises the power module as claimed in any one of claims 1 to 7.

9. The apparatus of claim 8, wherein, The power module comprises a shell and a substrate, the substrate is arranged in the shell, and the substrate is directly connected with a heat sink through the shell.

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