Plastic package type power module with high power density

Abstract

The utility model discloses a plastic package type power module with high power density. The plastic package type power module comprises a plastic package shell, a ceramic copper-clad plate, a semiconductor chip attached to the ceramic copper-clad plate, a power terminal and a signal terminal, wherein one end of the power terminal is connected to the ceramic copper-clad plate, and the other end of the power terminal extends out of the plastic package shell of the power module; the semiconductor chip is connected to the power terminal through the clip terminal and the copper layer of the ceramic copper-clad plate, and the power terminal, the signal terminal and the clip terminal are connected with the ceramic copper-clad plate through an ultrasonic welding process; the cli p terminal is of an integrated structure and comprises a flat-plate-shaped main body and connecting pins which extend towards the two sides and extend downwards to the ceramic copper-clad plate or the semiconductor chip. According to the utility model, the aluminum wire or copper wire bonding is replaced by the clip terminal welding, so that the large-current application can be met; the design of the clip terminals can ensure that the height and the length are consistent, and can meet the requirement of large-current application, thereby ensuring the consistency of stray inductance and reducing the inductance at the same time.

Description

Technical Field

[0001] The utility model relates to the technical field of power modules, and specifically to a plastic-encapsulated power module with high power density. Background Art

[0002] At present, power modules are widely used in power electronic circuits, and are usually packaged in semiconductor packaging. Power semiconductor packaging technology includes issues such as material selection, structural design, process design, and packaging technology. Many power chips are packaged into modules through verification calculations and a more beautiful and symmetrical layout. Power modules usually include a heat dissipation copper plate, a ceramic copper clad plate arranged on the heat dissipation copper plate, a semiconductor chip mounted on the ceramic copper clad plate, signal terminals and power terminals connected to the ceramic copper clad plate, and a shell.

[0003] A high power density power module refers to a power electronic component that provides the highest possible power output within a limited volume or space. In the prior art, the connection between the signal terminal and the ceramic copper clad laminate is usually made through a bonding process. In high current application scenarios, it is prone to failures such as bonding detachment, and has gradually failed to meet the application requirements of high power density power modules. In addition, the arc height of the bonding wire varies, the loop is too long, and the stray inductance is high, which is not conducive to construction in the application system, and the performance cannot be further improved. At the same time, high power density means higher heat generation, requiring an efficient heat dissipation solution. The existing modules are sealed with glue, which has poor heat dissipation capabilities and cannot meet high temperature and high power application scenarios. Utility Model Content

[0004] In view of the above technical problems, the utility model proposes a high-power density plastic-encapsulated power module, which uses clip terminal welding instead of aluminum wire or copper wire bonding, so that the power module can meet high-current application scenarios and has excellent electrical and thermal conductivity.

[0005] A high power density plastic-encapsulated power module, comprising a plastic-encapsulated shell, a ceramic copper-clad board, a semiconductor chip mounted on the ceramic copper-clad board, a power terminal and a signal terminal connected to the ceramic copper-clad board at one end and extending out of the power module plastic-encapsulated shell at the other end; preferably, the semiconductor chips are symmetrically arranged on both sides of the ceramic copper-clad board, and the semiconductor chips on each side are staggered; preferably, the plastic-encapsulated shell is formed by integrally coating with epoxy resin through an injection molding process.

[0006] The semiconductor chip is connected to the power terminal through the copper layer of the ceramic copper clad board via the clip terminal, and the power terminal, the signal terminal, and the clip terminal are all connected to the ceramic copper clad board through an ultrasonic welding process. The clip terminal is an integrated structure, including a flat plate-shaped body and connecting pins extending to both sides and extending downward to the ceramic copper clad board or the semiconductor chip.

[0007] Preferably, the ceramic copper clad laminate is welded to the bottom plate through a solder tab.

[0008] Preferably, the bottom plate is a water-cooled heat dissipation bottom plate; a water-cooled cavity is provided on the side of the bottom plate facing away from the ceramic copper clad laminate; the water-cooled cavity is composed of a fence and a number of internal drainage columns, and the drainage columns are staggered on the bottom plate.

[0009] Preferably, the power terminal and the signal terminal form a terminal frame through a connecting piece, which is convenient for butt welding with the ceramic copper clad laminate.

[0010] The utility model adopts clip terminal welding to replace aluminum wire or copper wire bonding, which can meet high-current applications and has excellent electrical and thermal conductivity. The clip terminal design can ensure the same height and length, thus ensuring the consistency of stray inductance and reducing inductance at the same time; in addition, the main body size of the clip terminal can be adaptively designed according to the magnitude of the passing current, with high matching degree and suitable for power modules with high power density. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic perspective view of the overall structure of a plastic-encapsulated power module with high power density;

[0012] Figure 2 It is a schematic perspective view of the internal structure of a plastic-encapsulated power module with high power density;

[0013] Figure 3 It is a schematic plan view of the internal structure of a plastic-encapsulated power module with high power density;

[0014] Figure 4 It is a schematic view of the clip terminal structure;

[0015] Figure 5 It is a schematic view of the semiconductor chip arrangement;

[0016] Figure 6 It is a schematic view of the drainage column arrangement;

[0017] Figure 7 It is a schematic view of the terminal frame. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The present utility model will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present utility model are given for purposes of illustration and description, and are not exhaustive or limit the present utility model to the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present utility model, and enable those of ordinary skill in the art to understand the present utility model and thus design various embodiments with various modifications suitable for specific purposes.

[0019] Embodiment 1

[0020] A plastic-encapsulated power module with high power density, as Figures 1-3 shown, includes a plastic encapsulation housing 9, a ceramic copper clad laminate 1, semiconductor chips 2 mounted on the ceramic copper clad laminate 1, power terminals 3 and signal terminals 4 with one end connected to the ceramic copper clad laminate 1 and the other end extending out of the plastic encapsulation housing of the power module.

[0021] The semiconductor chips 2 are connected to the power terminals 3 through clip terminals 5 via the copper layer of the ceramic copper clad laminate 1, and the power terminals 3, the signal terminals 4, and the clip terminals 5 are all connected to the ceramic copper clad laminate 1 by ultrasonic welding process.

[0022] In this embodiment, clip terminal welding is used instead of aluminum wire or copper wire bonding, which can meet high-current applications and has excellent electrical conductivity and thermal conductivity. Referring to Figure 4 shown, the clip terminal 5 is an integral structure, including a flat-shaped main body and connecting legs extending to both sides and probing down to the ceramic copper clad laminate 1 or the semiconductor chips 2.

[0023] The clip terminal design can ensure consistent height and length, thus ensuring consistent stray inductance and reducing inductance at the same time. In addition, the main body size of the clip terminal can be adaptively designed according to the magnitude of the current passing through, with high matching degree, and is suitable for power modules with high power density.

[0024] For facilitating circuit layout, the semiconductor chips 2 are symmetrically arranged on both sides of the ceramic copper clad laminate 1; for facilitating circuit connection, the semiconductor chips 2 on each side are arranged staggeredly, as Figure 5 shown. The welding of the chips to the ceramic copper clad laminate is preferably by silver sintering. The silver has a high melting point, which can greatly improve the reliability.

[0025] The ceramic copper clad laminate 1 is welded to the bottom plate 7 through solder pads 6. To improve its heat dissipation effect, the bottom plate 7 is a water-cooled heat dissipation bottom plate. More specifically, a water-cooled cavity 8 is provided on the side of the bottom plate 7 facing away from the ceramic copper clad laminate 1. The water-cooled cavity 8 is composed of a fence 801 and several internal drainage columns 802, referring to Figure 1. In actual use, a cover plate is provided on the water-cooled cavity 8, and a water inlet and a water outlet are also provided on the cover plate. The cover plate can be an integral structure with other sheet metals, so it is not shown in the drawings of this embodiment.

[0026] To improve the water-cooling effect, the drainage columns 802 are staggered on the bottom plate 7, as Figure 6 shown, so as to extend the residence time of the water flowing into the water-cooled cavity 8 therein and improve the heat dissipation effect.

[0027] The power terminal 3 and the signal terminal 4 form a terminal frame through a connecting piece, as Figure 7 shown, which is convenient for butt welding with the ceramic copper clad laminate 1, as Figure 7 shown. After the terminals are welded, the redundant connecting pieces can be cut off. At the same time, the terminal frame adopts the ultrasonic welding process, which also improves the practicability of the signal terminals of the power semiconductor module, has high welding efficiency, and has obvious advantages such as better welding quality, environmental protection and energy saving than the reflow bonding welding process.

[0028] The plastic encapsulation housing 9 is integrally formed by plastic encapsulation of epoxy resin through an injection molding process. Epoxy resin plastic encapsulation has many advantages such as improved insulation withstand voltage, reduced volume, and improved heat dissipation capacity, meeting the application requirements of high-power density power modules.

[0029] Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art and related fields based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

Claims

1. A plastic-encapsulated power module with high power density, comprising a plastic-encapsulated housing (9), a ceramic copper-clad laminate (1), semiconductor chips (2) mounted on the ceramic copper-clad laminate (1), power terminals (3) and signal terminals (4) with one end connected to the ceramic copper-clad laminate (1) and the other end extending out of the plastic-encapsulated housing of the power module, characterized in that the semiconductor chips (2) are connected to the power terminals (3) through clip terminals (5) via the copper layer of the ceramic copper-clad laminate (1), and the power terminals (3), the signal terminals (4), and the clip terminals (5) are all connected to the ceramic copper-clad laminate (1) by ultrasonic welding process; the clip terminals (5) are of an integral structure, including a flat-shaped main body and connecting feet extending out to both sides and probing down to the ceramic copper-clad laminate (1) or the semiconductor chips (2).

2. The plastic-encapsulated power module with high power density according to claim 1, wherein The semiconductor chips (2) are symmetrically arranged on both sides of the ceramic copper-clad laminate (1), and the semiconductor chips (2) on each side are arranged staggeredly.

3. The plastic-encapsulated power module with high power density according to claim 1 or 2, characterized in that The ceramic copper-clad laminate (1) is welded to the bottom plate (7) through solder pads (6).

4. The plastic-encapsulated power module with high power density according to claim 3, characterized in that, The bottom plate (7) is a water-cooled heat dissipation bottom plate.

5. The plastic-encapsulated power module with high power density according to claim 4, characterized in that, A water-cooled cavity (8) is provided on one side of the bottom plate (7) facing away from the ceramic copper-clad laminate (1).

6. The plastic-encapsulated power module with high power density according to claim 5, characterized in that The water-cooled cavity (8) is composed of a fence (801) and a number of internal drainage columns (802).

7. The plastic-encapsulated power module with high power density according to claim 6, wherein The drainage columns (802) are staggeredly distributed on the bottom plate (7).

8. The plastic-encapsulated power module with high power density according to claim 1, characterized in that, The power terminals (3) and the signal terminals (4) form a terminal frame through a connecting piece, which is convenient for butt welding with the ceramic copper-clad laminate (1).

9. The plastic-encapsulated power module with high power density according to claim 1, wherein, The plastic-encapsulated housing (9) is integrally formed by plastic encapsulation of epoxy resin through an injection molding process.

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