Power module, power module and packaging method thereof

Abstract

This application discloses a power module, comprising: a first insulating substrate; a first wiring layer located on the first insulating substrate; a plurality of power devices located on corresponding parts of the first wiring layer, each power device including a first terminal, a second terminal, and a third terminal; and a second busbar including a main busbar and a plurality of branch busbars, each branch busbar being electrically connected to the second terminal of a corresponding power device. This invention achieves similar conductive path lengths from each power device to the main busbar by connecting the multiple branch busbars to the sources of the corresponding power devices, thus realizing uniform current distribution.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more specifically, to a power module and its packaging method. Background Technology

[0002] Power modules are a new type of high-power power electronic device with advantages such as high current density, low saturation voltage and high voltage resistance. They are currently widely used in various fields such as production and daily life.

[0003] Power modules, as power semiconductor devices used in power electronic systems to achieve power conversion and control, typically require multiple power devices to be connected in parallel to meet increasing power demands. Existing power modules with multiple power devices connected in parallel often suffer from current sharing problems. This means that some power devices are affected by the current shunting from other power devices, resulting in uneven current distribution among the devices. This can lead to some devices experiencing excessive current and overheating failure. Furthermore, existing parallel multi-power device connections also exhibit switching oscillation problems. Due to the varying lengths of the gate and source circuit paths of each power device and the long coupling of power circuit inductance, the switching times of the gates of each device are inconsistent. Crosstalk between multiple power devices causes instability in the gate voltage, source-drain current, and voltage among the parallel power devices, resulting in significant oscillations. This negatively impacts the overall performance of the power module. Summary of the Invention

[0004] In view of the above problems, the purpose of this invention is to provide a power module to improve the current distribution of each power device in the power module, reduce uneven current distribution and switching oscillation problems, and improve the electrical performance of the power module.

[0005] The present invention provides a power module, comprising: a first insulating substrate; a first wiring layer located on the first insulating substrate; a plurality of power devices located on corresponding first wiring layers, each power device including a first end, a second end and a third end; and a second bus section including a main bus section and a plurality of branch bus sections connected to the main bus section, the plurality of branch bus sections being electrically connected to the second end of the corresponding power devices.

[0006] Optionally, the first end of the power device is electrically connected to the first power terminal of the power module, the second end of the power device is electrically connected to the second power terminal of the power module, the third end of the power device is electrically connected to the control terminal of the power module, and the main bus is electrically connected to the second power terminal.

[0007] Optionally, multiple branch busbars are electrically connected to the second terminal of the respective power device via a second metal interconnect layer, a bonding wire, or a bonding strip.

[0008] Optionally, the first end of the power device is electrically connected to the first power terminal of the power module via a brazing layer, a sintering layer, or a eutectic bond or conductive adhesive.

[0009] Optionally, the first wiring layer includes a first portion of the first wiring layer, a second portion of the first wiring layer, and a third portion of the first wiring layer that are isolated from each other.

[0010] Optionally, the power module further includes a first busbar, which is electrically connected to the first power terminal via a first metal interconnect layer and a first portion of the first wiring layer.

[0011] Optionally, the second power terminal and the main busbar are integral metal clips.

[0012] Optionally, the second power terminal and the main busbar are separate metal clips.

[0013] Optionally, at least a portion of the main bus section is a bond line or bond band.

[0014] Optionally, the main busbar and the branch busbar are integrated metal clips.

[0015] Optionally, the main busbar and the branch busbar are separate metal clips.

[0016] Optionally, the branch bus sections corresponding to some adjacent power devices are integrated into one structure.

[0017] Optionally, the branch bus sections corresponding to some adjacent power devices are discrete structures, and are interconnected through the second ends of some adjacent power devices by one of the following: bonding wire, bonding tape, or discrete metal clip.

[0018] Optionally, the currents of the main bus and the multiple branch bus intersect at a converging end. The main bus includes a first end and a second end, and the converging end is located at the first end of the main bus. The distance from the first end of the main bus to the second power terminal is greater than the distance from the first end of the main bus to the second power terminal.

[0019] Optionally, the power module also includes a sampling terminal, the second end of which is electrically connected to the converging terminal.

[0020] Optionally, the convergence end and the second end of the sampling terminal are interconnected by a bonding wire or bonding tape.

[0021] Optionally, the second end of the convergence terminal and the second end of the sampling terminal are interconnected with the second part of the partial first wiring layer through a third metal interconnect layer.

[0022] Optionally, the second end of the sampling terminal is electrically connected to the second power terminal, and the second end of the sampling terminal is an integral part of the main bus.

[0023] Optionally, the power module also includes a sampling terminal, the second end of which is electrically connected to the second end of the power device via a bonding wire, bonding strip, or metal clip.

[0024] Optionally, the power module further includes a sampling terminal, the second end of which is electrically connected to the branch bus via a bonding wire, bonding tape, or metal clip.

[0025] Optionally, during the turn-on process of each power device, the control current flows through the control terminal, the third terminal of each power device, the second terminal of each power device, the branch bus, the main bus, converges to the convergence terminal, and then flows through the second part of the first wiring layer, the bonding wire or the bonding strip to the sampling terminal.

[0026] Optionally, during the turn-on process of each power device, the control current flows through the control terminal, the third terminal of each power device, the second terminal of each power device, the branch busbar, the main busbar, converges to the convergence terminal, and then flows to the sampling terminal.

[0027] Optionally, during the turn-on process of each power device, the control current flows through the control terminal, the third terminal of each power device, the second terminal of each power device, the branch bus, and then through one of the following: bonding wire, bonding strip, or metal clip, to the sampling terminal.

[0028] Optionally, when each power device is forward-biased, the current flows sequentially through: the first power terminal, the first busbar, through the first part of the first wiring layer, through the first end of each power device, the second end of each power device, the branch busbar, then converges into the main busbar, the second busbar, and finally outputs through the second power terminal.

[0029] Optionally, the main bus is located above the power devices, and a portion of the main bus's projection onto the first insulating substrate lies between partially adjacent power devices.

[0030] Optionally, the second bus section further includes a second insulating substrate and a second wiring layer, the second wiring layer being located on the second insulating substrate, the second insulating substrate being located on the first wiring layer, the second insulating substrate and the second wiring layer being located between partially adjacent power devices, and the second wiring layer being electrically connected to multiple branch bus sections and the main bus section.

[0031] Optionally, the second busbar of the power module further includes a fourth wiring layer independent of the first wiring layer. The fourth wiring layer is located between some adjacent power devices. The first surface of the fourth wiring layer is electrically connected to the plurality of branch busbars and the main busbar. The second surface of the fourth wiring layer is located on the first insulating substrate.

[0032] Optionally, the branch bus section is a bond line or a bond band.

[0033] Optionally, the power devices are arranged in two columns.

[0034] Optionally, there are four power devices, and the branch bus section includes four connection terminals, which are respectively connected to the first terminals of the four power devices.

[0035] Optionally, the first insulating substrate further includes a heat dissipation base plate, which is exposed on the lower surface of the molding compound.

[0036] Optionally, the power device is a metal-oxide-semiconductor field-effect transistor or a silicon carbide metal-oxide-semiconductor field-effect transistor.

[0037] Optionally, the first power terminal is a drain power terminal, the second power terminal is a source power terminal, the power module control terminal is a gate control terminal, the first end of the power device is the drain, the second end of the power device is the source, and the third end of the power device is the gate.

[0038] Optionally, the power module further includes a molding compound that at least covers a first insulating substrate, a first wiring layer, and a power device. The molding compound includes opposing first and second sides, as well as opposing third and fourth sides, with the first and third sides of the molding compound being perpendicular. A first power terminal extends from the first side of the molding compound, a second power terminal extends from the second side of the molding compound, and the first ends of the control terminal and the sampling terminal of the power module extend from the second side of the molding compound.

[0039] Optionally, some adjacent power devices may be located in the same row.

[0040] According to another aspect of the present invention, a power module is provided, wherein the power module employs the aforementioned power module.

[0041] According to another aspect of the present invention, a method for packaging a power module is provided, wherein the power module employs the aforementioned power module.

[0042] According to the power module, power assembly, and power assembly packaging method provided by the present invention, the second bus component includes a main bus and multiple branch bus. The multiple branch bus are electrically connected to the second terminal (such as the source of a metal-oxide-semiconductor field-effect transistor or a silicon carbide metal-oxide-semiconductor field-effect transistor) of the corresponding power device. When the forward is turned on, the current flows sequentially through: the first power terminal, the first bus, through the first part of the first wiring layer through the first terminal of each power device, the second terminal of each power device, the branch bus, and then converges to the main bus, the second bus, and finally output through the second power terminal, so as to achieve that the conductive path length from each power device to the main bus is similar and to achieve uniform current distribution.

[0043] Furthermore, during the turn-on process of each power device, the control current flows through the control terminal, the third terminal of each power device (such as the gate of a metal-oxide-semiconductor field-effect transistor or a silicon carbide metal-oxide-semiconductor field-effect transistor), the second terminal of each power device (such as the source of a metal-oxide-semiconductor field-effect transistor or a silicon carbide metal-oxide-semiconductor field-effect transistor), the branch bus, the main bus, converges to the converging terminal, and then flows through the second part of the first wiring layer or the bonding wire to the sampling terminal, thereby reducing switching oscillation. Alternatively, during the turn-on process of each power device, the control current flows through the control terminal, the third terminal of each power device (such as the gate of a metal-oxide-semiconductor field-effect transistor or a silicon carbide metal-oxide-semiconductor field-effect transistor), the second terminal of each power device (such as the source of a metal-oxide-semiconductor field-effect transistor or a silicon carbide metal-oxide-semiconductor field-effect transistor), the branch bus, the main bus, converges to the converging terminal, and then flows to the sampling terminal, thereby reducing switching oscillation.

[0044] The power module provided by the present invention can also use a second insulating substrate and a second wiring layer to further reduce the size of the power module, and can be flexibly adjusted according to requirements. The second insulating copper-clad substrate is the aforementioned second insulating substrate and second wiring layer. Attached Figure Description

[0045] The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0046] Figure 1 An exploded view of the power module according to the first embodiment of the present invention is shown;

[0047] Figure 2 A perspective view of a power module according to a first embodiment of the present invention is shown;

[0048] Figure 3 A schematic diagram of a power module according to a first embodiment of the present invention is shown;

[0049] Figure 4 A schematic diagram showing the current path when the power module of the first embodiment of the present invention is forward turned on;

[0050] Figure 5 A schematic diagram showing the control current path of the power module according to the first embodiment of the present invention is provided.

[0051] Figure 6 A schematic diagram of the equivalent circuit of the power module according to the first embodiment of the present invention is shown;

[0052] Figure 7 A schematic diagram of a power module according to a second embodiment of the present invention is shown;

[0053] Figure 8A schematic diagram of a power module according to a third embodiment of the present invention is shown;

[0054] Figure 9 A perspective view of a power module according to a third embodiment of the present invention is shown;

[0055] Figure 10 A schematic diagram of a power module according to a fourth embodiment of the present invention is shown;

[0056] Figure 11 An exploded view of the power module according to the fourth embodiment of the present invention is shown;

[0057] Figure 12 A schematic diagram of a power module according to a fifth embodiment of the present invention is shown;

[0058] Figure 13 A schematic diagram of a power module according to a sixth embodiment of the present invention is shown;

[0059] Figure 14 A schematic diagram of a power module according to a seventh embodiment of the present invention is shown;

[0060] Figure 15 A schematic diagram of a power module according to an eighth embodiment of the present invention is shown;

[0061] Figure 16 A schematic diagram of a power module according to a ninth embodiment of the present invention is shown;

[0062] Figure 17 A schematic diagram of a power module according to the tenth embodiment of the present invention is shown;

[0063] Figure 18 A perspective view of a power module according to the eleventh embodiment of the present invention is shown;

[0064] Figure 19 A schematic diagram of a power module according to the twelfth embodiment of the present invention is shown;

[0065] Figure 20 A perspective view of a power module according to the twelfth embodiment of the present invention is shown;

[0066] Figure 21 The control current path of the power module in the twelfth embodiment of the present invention;

[0067] Figure 22 A three-dimensional schematic diagram of a power module according to a fifth embodiment of the present invention is shown. Detailed Implementation

[0068] The invention will now be described in more detail with reference to the accompanying drawings. For clarity, the various parts in the drawings are not drawn to scale. Furthermore, some well-known parts may not be shown. Many specific details of the invention are described below, but as those skilled in the art will understand, the invention can be implemented without following these specific details.

[0069] This invention can be presented in various forms, some of which will be described below.

[0070] Figures 1 to 22 A schematic diagram of the power module of the present invention is shown. The power module 100 includes a first insulating substrate 101, a first wiring layer 102, a plurality of power devices 103, a first bus 120, a second bus 130, a sampling terminal 134, a control terminal 136, and a molding compound 106. The first wiring layer 102 is located on the first insulating substrate 101. There are multiple power devices 103 located on the first wiring layer 102. Specifically, the power devices 103 are, for example, metal-oxide-semiconductor field-effect transistors (MOSFETs), silicon carbide MOSFETs, or insulated-gate bipolar transistors (IGBTs). Each power device includes a first terminal, a second terminal, and a third terminal. The embodiments of this application are described using IGBTs or silicon carbide MOSFETs as examples, where the first terminal of the power device is the drain, the second terminal is the source, and the third terminal is the gate. However, the power devices of this application are not limited to these embodiments. The gate of the power device is connected to the control terminal 136 of the power module via a bonding wire and the third part of the first wiring layer 102; the second bus 130 includes a main bus 131 and a plurality of branch bus 132, the plurality of branch bus 132 being connected to the source of the corresponding power device 103 via a second metal interconnect layer 112, a bonding wire or a bonding strip, and the main bus 131 being electrically connected to the second power terminal 133.

[0071] Figures 1 to 22 The power devices 103 shown are, for example, four, which can be arranged in a 2x2 array, but this application is not limited to four power devices, and the arrangement of the power devices is not limited to a matrix arrangement. Each power device 103 includes a drain, a source, and a gate. The drain of the power device is electrically connected to the first power terminal 121 of the power module through a solder layer, sintering layer, eutectic bonding, or conductive adhesive 111 on its lower surface.

[0072] The power module also includes a first bus 120, such as Figure 1 , Figure 11 The exploded view of the power module shown shows that the first bus 120 is electrically connected to the first power terminal 121 via the first metal interconnect layer 113 and the first part of the first wiring layer 102.

[0073] Figure 1 , Figure 3 , Figure 4 , Figure 5 , Figure 7 , Figure 8 , Figure 10-17 , Figure 19 , Figure 21 The power module 100 of the present invention further includes a molding compound 106, which at least covers a first insulating substrate 101, a first wiring layer 102, and a power device 103. The molding compound 106 includes opposing first and second sides, as well as opposing third and fourth sides. The first and third sides of the molding compound 106 are perpendicular. A first power terminal 121 extends from the first side of the molding compound 106, and a second power terminal 133 extends from the second side of the molding compound 106. A sampling terminal 134 and a control terminal 136 also extend from the second side of the molding compound 106. Specifically, the sampling terminal 134 is located, for example, between the control terminal 136 and the second power terminal 133 to ensure the distance between the second power terminal 133 and the control terminal 136.

[0074] like Figures 1 to 5 The first embodiment shown Figure 7 The second embodiment shown Figures 8 to 22 In the third to twelfth embodiments shown, the currents of the main bus 131 and the multiple branch bus 132 intersect at the converging terminal 135. The main bus includes a first end and a second end, and the converging terminal 135 is located at the first end of the main bus 131. The distance from the first end of the main bus 131 to the second power terminal 133 is greater than the distance from the first end of the main bus 131 to the second power terminal 133. The power module also includes a sampling terminal 134, the second end of which is electrically connected to the converging terminal 135.

[0075] like Figures 1 to 5 , Figure 7 As shown, the second end of the convergence terminal 135 and the sampling terminal 134 are interconnected through the third metal interconnect layer 114 and the second part of the first wiring layer 102.

[0076] like Figure 12 and Figure 22 As shown, the second end of the sampling terminal 134 and the converging terminal 135 are integrated into one structure. During the turn-on process of each power device, the control current flows through the control terminal, the third end of each power device, the second end of each power device, the branch bus, the main bus, converges to the converging terminal, and then flows to the sampling terminal.

[0077] The second end of sampling terminal 134 is electrically connected to the second end of the power device via a bonding wire;

[0078] To better illustrate the internal structure of this power module, Figure 2 , Figure 9 , Figure 18 , Figure 20 , Figure 22 The plastic sealant has been omitted. For example... Figures 1 to 5 , Figure 7 As shown, the first wiring layer 102 includes, for example, a first portion, a second portion, and a third portion of the first wiring layer that are not connected to each other. For example, the first portion of the first wiring layer may be a U-shaped region, the second portion an L-shaped region, and the third portion a strip-shaped region. However, the shapes of the first, second, and third portions of the first wiring layer in this application are not limited to those described above. The first insulating substrate 101 also includes a heat dissipation base plate, which is exposed on the lower surface of the molding compound 106. In this embodiment, the power devices include, for example, four, arranged in a 2*2 array on the first part of the first wiring layer, i.e., the U-shaped area. In this embodiment, the second bus 130 includes, for example, an H-shaped structure. However, the structure of the second bus in this application is not limited to the shape disclosed in this embodiment. The second bus 130 in this embodiment has four protruding branch bus 132, which are respectively connected to the sources of the four power devices 103. Each branch bus 132 is electrically connected to the second power terminal 133 through the main bus 131. In this embodiment, the second end of the sampling terminal 134 is connected to one end of the second part (L-shaped area) of the first wiring layer 102 through a bonding wire, and the other end of the second part (L-shaped area) of the first wiring layer 102 is electrically connected to the converging end 135. The gates of the two power devices 103 on the left are connected to the left end of the third part (i.e., the strip area) of the first wiring layer 102 via bonding wires. The gates of the two power devices 103 on the right are connected to the right end of the third part (i.e., the strip area) of the first wiring layer 102 via bonding wires. The third part (i.e., the strip area) of the first wiring layer 102 is then electrically connected to the control terminal 136 via bonding wires.

[0079] like Figures 1 to 22 The first power terminal 121 of the power module shown is an integral metal clip with the first busbar 120, as shown. Figures 1 to 5 , Figures 8 to 15 , Figures 17 to 22 The second power terminal 131 of the power module shown is an integral metal clip with the second busbar 130.

[0080] Figure 4 A schematic diagram showing the current path of the power module during forward turn-on according to the first embodiment of the present invention is provided; to clearly illustrate the current path, red arrows are used to indicate the current path of the power module during forward turn-on. Figure 4As shown, when each power device 103 is forward-biased, the current flows sequentially through: the first power terminal 121, the first busbar 120, through the first part of the first wiring layer 102, through the drain of each power device, the source of each power device, the branch busbar 132, then converges to the main busbar 131, the second busbar 130, and finally outputs through the second power terminal 133. The current path when the power module in the second to twelfth embodiments is forward-biased is the same. Figure 4 Similar to what is shown. From Figure 4 As can be clearly seen, based on the current sharing design of this power module, each power device only needs to bear one-quarter of the total current, and there is no uneven situation where individual power devices bear a large load. The power module of this application carries a similar current, and the conductive path length from each power device to the main bus region is also similar, which can effectively achieve uniform current distribution and improve system stability.

[0081] Figure 5 This diagram illustrates the control current of the power module according to the first embodiment of the present invention during the turn-on process of each power device. Figure 6 In this diagram, multiple power devices are equivalent to a single silicon carbide metal-oxide-semiconductor field-effect transistor (MOSFET), where D corresponds to the first power terminal 121, S corresponds to the second power terminal 133, the gate terminal G corresponds to the control terminal 136, and KS corresponds to the sampling terminal 134. Similarly, to clearly show the control current loop, red arrows are used to indicate the control current path. Figure 5 As shown, during the turn-on process of each power device 103, the control current flows through the control terminal 136, the gate of each power device 103, the source of each power device 103, the branch bus 132, the main bus 131, converges to the convergence terminal 135, and then passes through the second part of the first wiring layer 102. Figures 1 to 5 , Figure 7 The signal flows through the first wiring layer 102 or the bonding wire to the sampling terminal 134.

[0082] Since the converging terminal 135 is located near the main bus 131, it ensures the symmetry and proximity of the control current loops of each power device. Furthermore, the converging terminal 135 is located at the first end of the main bus 131, which can reduce the influence of the main bus 131 on its control current. In addition, the first wiring layer 102 and the second bus 130 are on different planes. The design of the current flowing to the sampling terminal 134 through the second part of the first wiring layer 102 or the bonding line can further reduce the interference of power fluctuations on sampling.

[0083] Figure 7A schematic diagram of a power module according to a second embodiment of the present invention is shown. This second embodiment is similar to the first embodiment, except that in this second embodiment, the second busbar 130 and the second power terminal 133 are separate metal clips. Two additional areas are added to the first wiring layer 102 of the first insulating substrate 101, so that the second busbar 130 is electrically connected to the second power terminal 133 via a second portion of the first wiring layer 102. In this second embodiment, the second power terminal 133 is not directly connected to the second busbar 130 and the power device 103. Since the second power terminal 133 is partially located outside the molding compound 106, this design effectively avoids the problem of force being directly transmitted to the second busbar 130 and the power device 103 in the event of impacts or tension on the second power terminal 133, thus effectively improving product stability.

[0084] Figure 8 and Figure 9 A top view and a perspective view of a power module according to a third embodiment of the present invention are shown respectively. This third embodiment is similar to the first embodiment, except that in this third embodiment, the second busbar 130 employs multiple discrete metal clips. The main busbar also includes a second insulating substrate and a second wiring layer, which are designated as 141 in the figures. The second wiring layer is located on the second insulating substrate, which is located on the first wiring layer 102. The second insulating substrate and the second wiring layer are located between partially adjacent power devices 103. The second wiring layer is electrically connected to the multiple branch busbars 132 and the main busbar 131. The multiple branch busbars 132 of the second busbar 130 have two ends. One end of each branch busbar 132 is electrically connected to the source of the corresponding power device 103, and the other end is connected to the second wiring layer. The first surface of the second wiring layer is electrically connected to the multiple branch busbars 132 and the main busbar 131. Furthermore, to ensure that the current path lengths are similar, the distances between each branch bus 132 and the middle region of the second insulating substrate and the second wiring layer 141 are the same or similar. The main bus 131 of the second bus 130 is electrically connected to the middle region of the second wiring layer 141, and a second power terminal 133 is led out from the second side of the molding compound 106.

[0085] Of course, if the lateral dimension of the first insulating substrate is large enough and the electrical spacing between the two columns of power devices 103 is sufficient, a fourth wiring layer isolated from the first wiring layer can be provided in the middle of the first insulating substrate 101. The second insulating substrate and the second wiring layer 141 can be replaced by a similar rectangular wiring area. An independent fourth wiring layer can be separated from the first wiring layer 102. The second bus section 130 also includes a fourth wiring layer. The fourth wiring layer is located between some adjacent power devices 103. The first surface of the fourth wiring layer is electrically connected to the plurality of branch bus sections 132 and the main bus section 131. The second surface of the fourth wiring layer is located on the first insulating substrate 101.

[0086] The sampling terminal 134 is electrically connected to the middle of the fourth wiring layer via a bonding wire. The connection method of the control terminal 136 is the same as that in the first embodiment, and will not be described again.

[0087] By employing a second insulating substrate and a second wiring layer 141 or a fourth wiring layer, there is no direct physical connection between the power device 103 and the main busbar of the second busbar 130, thus achieving uniform current distribution. The use of a discrete metal clip also reduces the difficulty of metal clip processing, thereby lowering production costs. Furthermore, the use of a second insulating substrate and a second wiring layer 141 ensures sufficient heat dissipation area for the drain of the power device 103, increasing the product's heat dissipation capacity and thereby improving the product's current output specifications.

[0088] Figure 10 and Figure 11 The top view and exploded view of the power module of the fourth embodiment of the present invention are shown respectively. The fourth embodiment is similar to the third embodiment, except that the metal clips of the two separate branch junctions 132 located in the same row in the third embodiment are replaced by a horizontal strip metal clip covering the two power devices 103 in the same row. This design can reduce the amount of materials, reduce assembly steps, and improve production efficiency.

[0089] Figure 12 , Figure 22 A schematic diagram and a perspective view of the power module according to the fifth embodiment of the present invention are shown respectively. The fifth embodiment is similar to the fourth embodiment, except that its sampling terminal 134 and the converging terminal 135 are integrated into one structure. Such an integrated structure has better stability than the bonding wire, avoiding the bonding wire from shifting or collapsing during the production process, which would cause the position of the converging terminal to change.

[0090] Figure 13A schematic diagram of a power module according to a sixth embodiment of the present invention is shown. This sixth embodiment is similar to the fourth embodiment, except that the rectangular second insulating substrate and the second wiring layer 141 are changed from being arranged vertically to being arranged horizontally. Independent wiring layer areas are added on the left and right sides of the second insulating substrate and the second wiring layer 141 for the power device 103 to be connected to the control terminal 136. This can effectively reduce the length of the bonding wire, reduce the difficulty of setting the bonding wire, and reduce product defects caused by bonding wire problems.

[0091] Figure 14 A schematic diagram of a power module according to a seventh embodiment of the present invention is shown. This seventh embodiment is similar to the third embodiment, except that the rectangular second insulating substrate and the second wiring layer are changed from being arranged vertically to being arranged horizontally. Similarly, independent wiring layer areas are added to the left and right sides of the second insulating substrate and the second wiring layer. The gate of the power device 103 is connected to the control terminal 136 after passing through the first part of the first wiring layer.

[0092] Figure 15 A schematic diagram of a power module according to an eighth embodiment of the present invention is shown. This eighth embodiment is similar to the sixth embodiment, except that in this eighth embodiment, the branch bus 132 in the second bus 130 of the sixth embodiment is replaced by a bonding wire instead of a metal clip.

[0093] Figure 16 A schematic diagram of a power module according to a ninth embodiment of the present invention is shown. This ninth embodiment is similar to the eighth embodiment, except that the main bus 131 in the second bus 130 of the eighth embodiment is replaced by a bonding wire instead of a metal clip in the ninth embodiment.

[0094] Figure 17 This diagram illustrates a power module according to a tenth embodiment of the present invention. This tenth embodiment is similar to the third embodiment, except that the second end of the sampling terminal 134 is electrically connected to the source of the power device 103 via a bonding wire.

[0095] Figure 18 A perspective view of a power module according to an eleventh embodiment of the present invention is shown. This eleventh embodiment is similar to the third embodiment, except that the second end of the sampling terminal 134 is electrically connected to the branch bus 132 via a bonding wire.

[0096] Figure 19 , Figure 20 , Figure 21 A schematic diagram, a perspective view, and a control current path diagram of the power module according to the twelfth embodiment of the present invention are shown respectively, as follows: Figure 19As shown, this twelfth embodiment is similar to the third embodiment, except that the second end of the sampling terminal 134 is electrically connected to the branch bus section via a bonding wire. Figure 21 As shown, during the turn-on process of each power device 103, the control current flows through the control terminal 136, the gate of each power device, the source of each power device, the branch bus 132, and then through the bonding wire or metal clamp to the sampling terminal 134.

[0097] According to the power module, power assembly, and power assembly packaging method provided by the present invention, the second bus component includes a main bus and multiple branch bus connected to the main bus. The multiple branch bus are electrically connected to the second terminal (such as the source of a metal-oxide-semiconductor field-effect transistor or a silicon carbide metal-oxide-semiconductor field-effect transistor) of the corresponding power device. When the forward is turned on, the current flows sequentially through: the first power terminal, the first bus, through the first part of the first wiring layer through the first terminal of each power device, the second terminal of each power device, the branch bus, and then converges to the main bus, the second bus, and finally output through the second power terminal, so as to achieve that the conductive path length from each power device to the main bus is similar and to achieve uniform current distribution.

[0098] Furthermore, during the turn-on process of each power device, the control current flows through the control terminal, the third terminal of each power device (such as the gate of a metal oxide semiconductor field-effect transistor or a silicon carbide metal oxide semiconductor field-effect transistor), the second terminal of each power device (such as the source of a metal oxide semiconductor field-effect transistor or a silicon carbide metal oxide semiconductor field-effect transistor), the branch bus, the main bus, converges to the convergence terminal, and then flows through the second part of the first wiring layer or the bonding line to the sampling terminal, thereby reducing switching oscillation.

[0099] Alternatively, during the turn-on process of each power device, the control current flows through the control terminal, the third terminal of each power device (such as the gate of a metal-oxide-semiconductor field-effect transistor or a silicon carbide metal-oxide-semiconductor field-effect transistor), the second terminal of each power device (such as the source of a metal-oxide-semiconductor field-effect transistor or a silicon carbide metal-oxide-semiconductor field-effect transistor), the branch bus, and then through one of the bonding wires, bonding strips, or metal clips to the sampling terminal.

[0100] Furthermore, the second busbar has superior current carrying capacity and thermal conductivity, which can effectively reduce the thermal resistance of the power module and improve heat dissipation. The power module has a stacked connection design in the vertical space. The connection structure formed by the vertical space and the first wiring layer simplifies the design of the first wiring layer, simplifies the manufacturing process, and reduces production costs. The power module has a reasonable layout, compact structure, and is easy to produce, install and maintain.

[0101] Furthermore, the use of a second insulating substrate and a second wiring layer can further reduce the size of the power module, and can be flexibly adapted to requirements. The second insulating copper-clad substrate can be the aforementioned second insulating substrate and second wiring layer.

[0102] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0103] As described above, these embodiments do not exhaustively describe all details, nor do they limit the invention to the specific embodiments described. Clearly, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to effectively utilize the invention and its modifications. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A power module, characterized in that, include: First insulating substrate; A first wiring layer is located on the first insulating substrate; Multiple power devices are located on corresponding first wiring layers, and each power device includes a first terminal, a second terminal, and a third terminal; The second busbar includes a main busbar and multiple branch busbars, each of which is electrically connected to the second terminal of a corresponding power device. The first end of the plurality of power devices is electrically connected to the first power terminal of the power module, the second end of the plurality of power devices is electrically connected to the second power terminal of the power module, the third end of the plurality of power devices is electrically connected to the control terminal of the power module, and the main bus is electrically connected to the second power terminal; The currents of the main bus and the multiple branch bus intersect at the converging end. The main bus includes a first end and a second end. The converging end is located at the first end of the main bus. The distance from the first end of the main bus to the second power terminal is greater than the distance from the second end of the main bus to the second power terminal. The power module also includes a first bus. The conductive path length from each power device to the main bus is similar, achieving uniform current distribution.

2. The power module according to claim 1, characterized in that, The multiple branch busbars are electrically connected to the second terminal of the corresponding power device via a second metal interconnect layer, a bonding wire, or a bonding strip.

3. The power module according to claim 1, characterized in that, The first end of the power device is electrically connected to the first power terminal of the power module via a brazing layer, a sintering layer, a eutectic bond, or conductive adhesive.

4. The power module according to claim 1, characterized in that, The first wiring layer includes a first portion of the first wiring layer, a second portion of the first wiring layer, and a third portion of the first wiring layer that are isolated from each other.

5. The power module according to claim 4, characterized in that, The first busbar is electrically connected to the first power terminal via the first metal interconnect layer and the first portion of the first wiring layer, and the plurality of power devices are located on the corresponding first portions of the first wiring layer.

6. The power module according to claim 1, characterized in that, The second power terminal and the main busbar are integral metal clips.

7. The power module according to claim 1, characterized in that, The second power terminal and the main busbar are separate metal clips.

8. The power module according to claim 1, characterized in that, At least a portion of the main bus section is a bonding wire or a bonding band.

9. The power module according to claim 1, characterized in that, The main busbar and the branch busbar are an integral metal clip.

10. The power module according to claim 1, characterized in that, The main busbar and the branch busbar are separate metal clips.

11. The power module according to claim 1, characterized in that, The branch busbars corresponding to some adjacent power devices are integrated into a single structure.

12. The power module according to claim 1, characterized in that, All the branch busbars corresponding to the power devices are integral metal clips.

13. The power module according to claim 1, characterized in that, The branch busbars corresponding to some adjacent power devices are discrete structures, and are interconnected through the second ends of some adjacent power devices by one of the following: bonding wire, bonding tape, or discrete metal clip.

14. The power module according to claim 1, characterized in that, The power module also includes a sampling terminal, the second end of which is electrically connected to the converging terminal.

15. The power module according to claim 14, characterized in that, The convergence end and the second end of the sampling terminal are interconnected by a bonding wire or bonding tape.

16. The power module according to claim 15, characterized in that, The convergence terminal and the second end of the sampling terminal are interconnected with the second part of the first wiring layer through a third metal interconnect layer, or the convergence terminal and the second end of the sampling terminal are directly interconnected with the second part of the first wiring layer.

17. The power module according to claim 14, characterized in that, The second end of the sampling terminal and the converging end are integrally formed.

18. The power module according to claim 1, wherein the power module further comprises a sampling terminal, the second end of the sampling terminal being electrically connected to the second end of the power device via a bonding wire, a metal clip, or a bonding tape.

19. The power module according to claim 1, wherein the power module further comprises a sampling terminal, the second end of the sampling terminal being electrically connected to the branch bus via a bonding wire, a bonding strip, or a metal clip.

20. The power module according to any one of claims 14 to 16, characterized in that, During the turn-on process of each of the power devices, the control current flows through the control terminal, the third terminal of each of the power devices, the second terminal of each of the power devices, the branch bus, the main bus, converges to the convergence terminal, and then flows through the second part of the first wiring layer, the bonding wire or the bonding strip to the sampling terminal.

21. The power module according to claim 17, characterized in that, During the turn-on process of each power device, the control current flows through the control terminal, the third terminal of each power device, the second terminal of each power device, the branch bus, the main bus, converges to the convergence terminal, and then flows to the sampling terminal.

22. The power module according to any one of claims 17 to 19, characterized in that, During the turn-on process of each of the power devices, the control current flows through the control terminal, the third terminal of each of the power devices, the second terminal of each of the power devices, the branch bus, and then through one of the bonding wires, bonding strips, or metal clips to the sampling terminal.

23. The power module according to claim 5, characterized in that, When each of the power devices is forward-biased, the current flows sequentially through: the first power terminal, the first busbar, through the first part of the first wiring layer, through the first end of each power device, the second end of each power device, the branch busbar, then converges to the main busbar, the second busbar, and finally outputs through the second power terminal.

24. The power module according to claim 1, characterized in that, The main bus is located above the power devices, and a portion of the projection of the main bus onto the first insulating substrate lies between the partially adjacent power devices.

25. The power module according to claim 1, characterized in that, The second busbar also includes a second insulating substrate and a second wiring layer, the second wiring layer being located on the second insulating substrate, the second insulating substrate being located on the first wiring layer, the second insulating substrate and the second wiring layer being located between partially adjacent power devices, and the second wiring layer being electrically connected to the plurality of branch busbars and the main busbar.

26. The power module according to claim 1, characterized in that, The second busbar also includes a fourth wiring layer that is independent of the first wiring layer. The fourth wiring layer is located between some of the adjacent power devices. The first side of the fourth wiring layer is electrically connected to the plurality of branch busbars and the main busbar. The second side of the fourth wiring layer is located on the first insulating substrate.

27. The power module according to claim 1, characterized in that, The branch junction is one of a bonding wire, a bonding tape, or a metal clip.

28. The power module according to claim 1, characterized in that, The power devices are arranged in two columns.

29. The power module according to claim 1, characterized in that, The power device is four in number, and the branch bus includes four connection terminals, which are respectively connected to the second terminals of the four power devices.

30. The power module according to claim 1, characterized in that, The first insulating substrate also includes a heat dissipation base plate, which is exposed on the lower surface of the molding compound.

31. The power module according to claim 1, characterized in that, The power devices are metal-oxide-semiconductor field-effect transistors (MOSFETs) and silicon carbide metal-oxide-semiconductor field-effect transistors (SMTs).

32. The power module according to claim 31, characterized in that, The first power terminal is a drain power terminal, the second power terminal is a source power terminal, the power module control terminal is a gate control terminal, the first end of the power device is the drain, the second end of the power device is the source, and the third end of the power device is the gate.

33. The power module according to claim 1, characterized in that, The power module further includes a molding compound that at least covers the first insulating substrate, the first wiring layer, and the power device. The molding compound includes opposing first and second sides, as well as opposing third and fourth sides. The first and third sides of the molding compound are perpendicular to each other. The first power terminal extends from the first side of the molding compound, the second power terminal extends from the second side of the molding compound, and the first ends of the control terminal and the sampling terminal of the power module extend from the second side of the molding compound.

34. The power module according to any one of claims 11, 13, 24, 25 or 26, characterized in that... Some of the adjacent power devices are located in the same row.

35. A power module, characterized in that, The power module is the power module described in any one of claims 1 to 34.

36. A method for packaging a power module, characterized in that, The power module is the power module as claimed in any one of claims 1 to 34.

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