Packaging structure of a three-phase bridge power module

Abstract

The application provides a packaging structure of a three-phase bridge power module, comprising two base islands on the left and right, a plurality of chips and connecting pieces are stacked on each base island from bottom to top, and solder is filled between each layer. The packaging structure stacks and seals the upper pipe and the lower pipe together, reduces the packaging volume, and reduces the parasitic inductance. All the solders use nano-silver sintering process, which greatly improves the heat dissipation performance. All the electrical connection materials inside the package use Cu-clip, which can improve the heat dissipation performance and reduce the parasitic inductance compared with the traditional wire bonding process. DBC is used between the power chips for insulation, which improves the reliability and stability of the system. In order to improve the heat dissipation performance, the DBC is made of AlN material. The packaging structure makes the three-phase bridge power module more compact, reduces the parasitic inductance, improves the heat dissipation efficiency, and improves the reliability and stability of the system.

Description

Technical Field

[0001] This invention belongs to the field of power electronic device technology and relates to a packaging structure for a three-phase bridge power module. Background Technology

[0002] In the field of power electronics, three-phase bridge power modules are crucial components widely used in various power conversion and motor drive systems. These modules typically contain multiple power chips responsible for handling high-voltage and high-current conversion tasks. Traditional three-phase bridge power module packaging usually involves mounting six power chips in a flat arrangement on a frame or substrate. However, this packaging method has some drawbacks.

[0003] First, the connection between the chip electrodes and the package inlet terminals is typically achieved using wire bonding. This method is prone to damaging the chip electrodes during the soldering process, leading to performance degradation or malfunction. Furthermore, wire bonding increases the overall package size, requiring sufficient space to accommodate the wires and solder joints. This increased size poses a challenge for applications demanding high integration and miniaturization.

[0004] Secondly, using wire bonding increases the inductance of the entire circuit. Inductance is a physical quantity that stores magnetic energy in a circuit, and its magnitude depends on the current and magnetic flux. In a three-phase bridge power module, the inductance directly affects conversion efficiency, noise, and electromagnetic compatibility. A larger inductance leads to increased energy loss, reduced conversion efficiency, and may generate electromagnetic interference, affecting the stability and reliability of the system.

[0005] Therefore, traditional three-phase bridge power module packaging methods have some limitations in terms of miniaturization, high integration, and performance. Summary of the Invention

[0006] The purpose of this invention is to provide a packaging structure for a three-phase bridge power module, which solves the problems of large overall package size and large parasitic inductance in the prior art.

[0007] The specific technical solution of this invention is as follows:

[0008] A packaging structure for a three-phase bridge power module includes two base islands on the left and right sides, where, from bottom to top, a first power chip, a first connector, a lower DBC, a second connector, a second power chip, a third connector, an upper DBC, a fourth connector, a third power chip, and a fifth connector are stacked. The drain of the chip on the left base island is at the bottom, and the source of the chip on the right base island is at the bottom. Solder is filled between each layer. The first, third, and fifth connectors simultaneously contact the two power chips on the same layer, and the other end of each connector has an exposed pad at the bottom. The second and fourth connectors on the same side are separate chips and are connected to the base island on the same side. The gates of the six power chips are connected to corresponding chip connectors, and the other end of each chip connector has an exposed pad at the bottom.

[0009] The solder is produced using a nano-silver sintering process.

[0010] The DBC uses AlN material.

[0011] The connecting piece uses a Cu-clip.

[0012] The top of the package structure has only the exposed pad of the fifth connector.

[0013] The bottom of the package structure has exposed pads for two base islands, exposed pads for the first connecting piece, the third connecting piece, and the fifth connecting piece, and exposed pads for the chip connecting pieces for the six power chips.

[0014] This invention proposes a packaging structure for a three-phase bridge power module, which has the following advantages:

[0015] In the aforementioned packaging structure, the upper and lower transistors are stacked together, reducing the package size and parasitic inductance. This packaging method makes the three-phase bridge power module more compact, reduces its footprint, and also helps improve the system's reliability and stability.

[0016] All solders utilize a nano-silver sintering process, significantly improving heat dissipation performance. The nano-silver sintering process possesses excellent thermal and electrical conductivity, resulting in a tighter bond between the solder and the chip and substrate, thus enhancing heat dissipation efficiency.

[0017] All internal electrical connections within the package utilize Cu-clip, which improves heat dissipation and reduces parasitic inductance compared to traditional wire bonding. Cu-clip offers excellent thermal and electrical conductivity, effectively transferring heat generated by the chip to the heatsink while also helping to reduce parasitic inductance and improve circuit stability and reliability.

[0018] To ensure insulation between the upper and lower power chips, DBC insulation is used between each power chip. DBC is a ceramic material with excellent insulation properties, which can effectively protect the electrical isolation between power chips and improve the reliability and stability of the system.

[0019] To improve heat dissipation performance, AlN material is used for the DBC. AlN is a ceramic material with high thermal conductivity and excellent electrical insulation properties, which can effectively transfer the heat generated by the chip to the heat sink, while also helping to reduce parasitic inductance and improve the stability and reliability of the circuit. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the three-phase bridge of the packaging structure described in this invention.

[0021] Figure 2 This is a top view of the packaging structure of the present invention.

[0022] Figure 3 This is a bottom view of the packaging structure of the present invention.

[0023] Figure 4 This is a cross-sectional view of the packaging structure of the present invention.

[0024] Figure 5 This is a longitudinal cross-sectional view of the packaging structure of the present invention. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings:

[0026] This invention proposes a packaging structure for a three-phase bridge power module, such as... Figures 2-5 As shown, the three-phase bridge principle of the packaging structure described in this invention is described in [reference needed]. Figure 1 .

[0027] See Figure 4 The present invention discloses a packaging structure for a three-phase bridge power module, wherein on the left and right base islands, the following layers are stacked from bottom to top: a first power chip, a first connecting piece, a lower DBC, a second connecting piece, a second power chip, a third connecting piece, an upper DBC, a fourth connecting piece, a third power chip, and a fifth connecting piece. The drain of the chip on the left base island is at the bottom, and the source of the chip on the right base island is at the bottom. The second and fourth connecting pieces on the same side are connected to the base island on the same side, and solder is filled between each layer.

[0028] As shown in the figure, the left base island 1 consists of the following components from bottom to top: Die 1-1 (drain D at the bottom), first connecting piece Clip1, DBC1-1, Clip1-2, Die 1-2 (drain D at the bottom), third connecting piece Clip3, Clip1-4, Die 1-3 (drain D at the bottom), and fifth connecting piece Clip5; Clip1-2 and Clip1-4 are connected to the left base island 1 respectively.

[0029] As shown in the figure, the base island 2 on the right side consists of Die 2-1 (with the source electrode S at the bottom), the first connecting piece Clip1, DBC2-1, Clip2-2, Die 2-2 (with the source electrode S at the bottom), the third connecting piece Clip3, Clip2-4, Die 2-3 (with the source electrode S at the bottom), and the fifth connecting piece Clip5 from bottom to top; Clip2-2 and Clip2-4 are connected to the base island 2 on the right side.

[0030] See Figure 5 Taking the left base island 1 as an example (the structure of the right base island 2 corresponds to the left base island 1), the first connecting piece Clip1, the third connecting piece Clip3, and the fifth connecting piece Clip5 correspond to the exposed pads at the bottom of the package structure; the gates G of Die 1-1 (bottom is drain D), Die 1-2 (bottom is drain D), and Die 1-3 (bottom is drain D) correspond to the chip connecting pieces ClipG-1, ClipG-2, and ClipG-3, respectively, and the chip connecting pieces ClipG-1 (i.e., G-1-1), ClipG-2 (i.e., G-1-2), and ClipG-3 (i.e., G-1-3) correspond to the exposed pads at the bottom of the package structure.

[0031] See Figure 2 The top of the package structure only has the exposed pad of the fifth connector, Clip5.

[0032] See Figure 3 The bottom of the package structure is provided with two exposed pads for base islands (base island-1 and base island-2 in the figure), the first connecting piece, the third connecting piece, and the fifth connecting piece corresponding to exposed pads U, V, and W respectively, and the exposed pads G-1-1, G-1-2, G-1-3, G-2-1, G-2-2, and G-2-3 for the chip connecting pieces corresponding to the six power chips.

[0033] To improve the heat dissipation performance of the power chip die, all solders are bonded using a nano-silver sintering process. Compared with traditional soldering processes, the improved process of this invention can significantly enhance heat dissipation performance.

[0034] To improve the heat dissipation performance of the power chip die and reduce parasitic inductance in the package, all electrical connection materials inside the package use Cu-clip. Compared with traditional wire bonding processes, Cu-clip can improve heat dissipation performance and reduce parasitic inductance.

[0035] To ensure insulation between the upper and lower transistors, DBCs are used to insulate the dies of each power chip. To improve heat dissipation, AlN material is used for the DBCs.

[0036] The above description, in conjunction with the accompanying drawings, provides a detailed account of the design and implementation schemes of the present invention. However, the present invention is not limited to the above-described embodiments and schemes. For those skilled in the art, any equivalent measures taken by them based on reading the present invention specification are within the scope of protection of the present invention.

Claims

1. A packaging structure for a three-phase bridge power module, characterized in that: On the left and right base islands, the chips are stacked from bottom to top as follows: first power chip - first connector - lower DBC - second connector - second power chip - third connector - upper DBC - fourth connector - third power chip - fifth connector. The drain of the chip on the left base island is at the bottom, and the source of the chip on the right base island is at the bottom. Solder is filled between each layer. The first connector, third connector, and fifth connector simultaneously contact the two power chips on the left and right sides of the same layer, and the other end of each of the three connectors has an exposed pad at the bottom. The second connector and fourth connector on the same side are connected to the base island on the same side. The gates of the six power chips are connected to the corresponding chip connectors, and the other end of each chip connector has an exposed pad at the bottom. The top of the package structure has only the exposed pad of the fifth connector; The bottom of the package structure has exposed pads for two base islands, exposed pads for the first connecting piece, the third connecting piece, and the fifth connecting piece, and exposed pads for the chip connecting pieces for the six power chips.

2. The packaging structure of a three-phase bridge power module according to claim 1, characterized in that: The solder is produced using a nano-silver sintering process.

3. The packaging structure of a three-phase bridge power module according to claim 2, characterized in that: The DBC uses AlN material.

4. The packaging structure of a three-phase bridge power module according to claim 3, characterized in that: The connecting piece uses a Cu-clip.

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