power device

Abstract

The present invention relates to a power device, comprising a plurality of power modules, a substrate comprising a metal surface, a chip disposed on the metal surface, a plurality of metal pillars disposed on the metal surface along a normal direction of the substrate, and each of the metal pillars comprising a top surface and a pillar body, and a packaging material covering the substrate, the chip and the plurality of metal pillars, wherein the pillar body of each of the metal pillars is completely covered by the packaging material, and the top surface of each of the metal pillars is exposed to a surface of the packaging material, each of the first current pins comprises a first end and a second end, the first end of at least one of the first current pins of each of the power modules is disposed on the top surface of the corresponding metal pillar by soldering or sintering, and the second end of the corresponding first current pin of the corresponding power module is disposed on the top surface of the corresponding metal pillar of another power module by soldering or sintering.

Description

Technical Field

[0001] This invention relates to a power device, and more particularly to a power device with high practicality. Background Technology

[0002] A power device comprises multiple power modules, each with a lead frame for transmitting signals and high current. Typically, the lead frames of power modules are sealed with adhesive, leaving some terminals exposed on the sides for connection to the system. However, traditional power devices can only connect to adjacent systems using the lead frame corresponding to a single power module; they cannot connect individual power modules to adjacent modules or between different power devices, thus limiting their applicability. Furthermore, because the lead frames of each power module in a traditional power device must be sealed in adhesive, the cost of repositioning or redesigning the lead frames is high, further complicating the overall practicality of the power device.

[0003] Therefore, developing a power device that overcomes the above-mentioned shortcomings is an urgent need at present. Summary of the Invention

[0004] The purpose of this invention is to provide a power device in which the top surface of a metal pillar is exposed to the surface of an encapsulation material. At least one first current pin of each power module is welded or sintered to the top surface of the corresponding metal pillar, and the second end of a corresponding first current pin of the same power module is welded or sintered to the top surface of the metal pillar of another power module. Therefore, the power modules of this invention can be connected to another power module at any position using their first current pins, thus improving the applicability of the power device. Furthermore, the first current pins of this invention are easily replaceable, resulting in improved overall practicality of the power device.

[0005] To achieve the above objectives, one embodiment of the present invention is a power device comprising multiple power modules. Each power module includes a substrate, a chip, multiple metal pillars, encapsulation material, and multiple first current pins. The substrate includes a metal surface. The chip is disposed on the metal surface. The multiple metal pillars are disposed on the metal surface along the normal direction of the substrate, and each metal pillar includes a top surface and a pillar body. The encapsulation material covers the substrate, the chip, and the multiple metal pillars, wherein the pillar body of each metal pillar is completely covered by the encapsulation material, and the top surface of each metal pillar is exposed on the surface of the encapsulation material. Each first current pin includes a first end and a second end. The first end of at least one first current pin of each power module is disposed on the top surface of the corresponding metal pillar by welding or sintering, and the second end of the corresponding first current pin of the corresponding power module is disposed on the top surface of the corresponding metal pillar of another power module by welding or sintering. Attached Figure Description

[0006] Figure 1 This is a top view of the power device of the present invention.

[0007] Figure 2 for Figure 1 A cross-sectional structural schematic diagram of the power module of the first embodiment of the power device shown.

[0008] Figure 3 for Figure 1 A cross-sectional view of the power module of the second embodiment of the power device shown.

[0009] Figure 4 for Figure 1 A top view of the power module of the third embodiment of the power device shown.

[0010] Figure 5 for Figure 1 The diagram shows a top view of the power module of the fourth embodiment of the power device.

[0011] Figure 6 for Figure 1 The diagram shows a top view of the power module of the fifth embodiment of the power device.

[0012] Figure 7 for Figure 1 A top view of the power module of the sixth embodiment of the power device shown.

[0013] Explanation of reference numerals in the attached figures 1: Power device, 10: System 2, 2a, 2b, 2c, 2d, 2e: Power modules 3: Substrate, 31: Metal surface, 4: Chips, 5: Metal pillars 51: Top surface 52: Bottom surface, 53: Pillar, 6: Packaging materials 71: First current pin 711: First end 712: Second end 713: Perforation, 72: Second current pin 721: First end 722: Second end 74: Connecting parts, 8: Metal wire bonding 91: Column solder, 92: Lead solder, H1, H2, H3: Thickness. Detailed Implementation

[0014] Some typical embodiments embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can be varied in different ways without departing from the scope of the invention, and the descriptions and drawings herein are for illustrative purposes only and not for limiting the invention.

[0015] Please see Figure 1 and Figure 2 ,in Figure 1 This is a top view of the power device of the present invention. Figure 2 for Figure 1 The diagram shows a cross-sectional view of the power module in the first embodiment of the power device. As shown, the power device 1 in this embodiment is connected to the system 10 and includes multiple power modules 2, for example... Figure 1 The three power modules 2 shown are interconnected, and the connection method will be explained later. Figure 2 As shown, each power module 2 includes a substrate 3, a chip 4, multiple metal pillars 5, packaging material 6, three first current pins 71, second current pins 72, and metal bonding wires 8. The substrate 3 includes a metal surface 31. The chip 4 is disposed on the metal surface 31 of the substrate 3. Figure 2 As shown, each metal post 5 can constitute a signal pin or a current pin, for example... Figure 2The two metal pillars 5 on the left and right sides of the chip 4 constitute current pins, and the metal pillar 5 in the middle constitutes a signal pin. Each metal pillar 5 is disposed on the metal surface 31 of the substrate 3 along the normal direction of the substrate 3 and is staggered with the chip 4. Each metal pillar 5 includes a top surface 51, a bottom surface 52, and a pillar body 53. The top surface 51 and bottom surface 52 of the metal pillar 5 are disposed opposite each other, and the pillar body 53 of the metal pillar 5 is disposed between the top surface 51 and the bottom surface 52. The bottom surface 52 of the metal pillar 5 is adjacent to the metal surface 31 of the substrate 3 relative to the top surface 51, and the top surface 51 of the metal pillar 5 is farther away from the metal surface 31 of the substrate 3 relative to the bottom surface 52. In this embodiment, as shown... Figure 1 As shown, each power module 2 includes four metal posts 5, which respectively constitute one DC negative terminal, two DC positive terminals, and one AC terminal of the power module 2. For example... Figure 1 The metal post 5 located above the power module 2 constitutes the DC negative terminal of the power module 2, the two metal posts 5 located on the left and right sides of the power module 2 constitute the two DC positive terminals of the power module 2, and the metal post 5 located below the power module 2 constitutes the AC terminal of the power module 2.

[0016] like Figure 2 As shown, the encapsulation material 6 covers the substrate 3, the chip 4 and a plurality of metal pillars 5. In other words, the substrate 3, the chip 4 and the plurality of metal pillars 5 are encapsulated in the encapsulation material 6, wherein the substrate 3, the chip 4 and the pillar body 53 of each metal pillar 5 are completely covered by the encapsulation material 6, and the top surface 51 of each metal pillar 5 is exposed on a surface of the encapsulation material 6 away from the substrate 3.

[0017] Each first current pin 71 is a high-current pin and includes a first end 711 and a second end 712. The first end 711 of at least one first current pin 71 of each power module 2 is soldered or sintered onto the top surface 51 of the corresponding metal pillar 5. In this embodiment, the first end 711 of the first current pin 71 is directly attached to the top surface 51 of the corresponding metal pillar 5 (i.e., the top surface 51 of the metal pillar 5 constituting the DC negative or DC positive terminal) by soldering or sintering. The second end 712 of the corresponding first current pin 71 of the corresponding power module 2 is soldered or sintered onto the top surface 51 of the metal pillar 5 corresponding to another power module 2 to provide current conduction between the two power modules 2. In this embodiment, the first end 711 of the first current pin 71 is directly attached to the top surface 51 of the corresponding metal pillar 5 using solderless soldering techniques such as ultrasonic soldering or laser soldering. In this embodiment, the width of the second end 712 of the first current pin 71 is equal to the width of the first end 711.

[0018] The second current pin 72 includes a first end 721 and a second end 722, wherein the first end 721 of at least one second current pin 72 of each power module 2 is disposed on the top surface 51 of the corresponding metal pillar 5 by welding or sintering. In this embodiment, the first end 711 of the second current pin 72 is directly attached to the top surface 51 of the corresponding metal pillar 5 (i.e., the top surface 51 of the metal pillar 5 constituting the AC terminal) by welding or sintering, and the second end 722 of the corresponding second current pin 72 of the corresponding power module 2 is disposed on the system connection terminal of the system 10 by welding or sintering to provide current conduction between the two power modules 2. In this embodiment, the first end 721 of the second current pin 72 is directly attached to the system connection terminal of the system 10 by solderless welding technology such as ultrasonic welding or laser welding. In this embodiment, the width of the second end 722 of the second current pin 72 is equal to the width of the first end 721. Metal bonding wires 8 are connected between the side of the chip 4 facing the substrate 3 and the metal surface 31 of the substrate 3 to provide current conduction between the chip 4 and the substrate 3. In this embodiment, the connection positions of the first current pin 71 and the second current pin 72 are designed to enable the three power modules 2 to achieve a series or parallel connection relationship. Of course, the three power modules 2 can also achieve a series or parallel connection relationship with other power modules by utilizing the connection positions of the first current pin 71 and the second current pin 72.

[0019] As can be seen from the above, the top surface 51 of the metal pillar 5 of the power device 1 of the present invention is exposed to the surface of the encapsulation material 6, and the first end 711 of at least one first current pin 71 of each power module 2 is disposed on the top surface 51 of the corresponding metal pillar 5 by welding or sintering, and the second end 712 of the corresponding first current pin 71 of the corresponding power module 2 is disposed on the top surface 51 of the metal pillar 5 of another power module 2 by welding or sintering. Therefore, compared with the conventional power device where the power module can only be connected to the adjacent power module, the power module 2 of the power device 1 of the present invention can be connected to another power module 2 at any position using the first current pin 71, making the power device 1 of the present invention more applicable. In addition, the first current pin 71 of the power device 1 of the present invention can be replaced more conveniently, thus the overall practicality of the power device 1 is better.

[0020] Please continue to participate. Figure 2The power module 2 further includes pillar solder 91, which is disposed and attached between the bottom surface 52 of the corresponding metal pillar 5 and the metal surface 31 of the substrate 3, and / or between the chip 4 and the metal surface 31 of the substrate 3. In this embodiment, the thickness H1 of each first current pin 71 of the power module 2 is less than the thickness H2 of the corresponding metal pillar 5 along the normal direction of the substrate 3, that is, the thickness H1 of each first current pin 71 of the power module 2 is less than the thickness H2 of the corresponding metal pillar 5 along the normal direction of the substrate 3, so that the first current pin 71 is easy to solder to the corresponding metal pillar 5. Similarly, the thickness H3 of each second current pin 72 of the power module 2 is less than the thickness H2 of the corresponding metal pillar 5 along the normal direction of the substrate 3, that is, the thickness H3 of each second current pin 72 of the power module 2 is less than the thickness H2 of the corresponding metal pillar 5 along the normal direction of the substrate 3, so that the second current pin 72 is easy to solder to the corresponding metal pillar 5.

[0021] Please see Figure 3 , it is Figure 1 A cross-sectional view of the power module of the second embodiment of the power device shown. Compared to Figure 2 The power module 2 shown in this embodiment, the power module 2a, also includes a lead solder 92, which is disposed and attached between the first end 711 of the corresponding first current lead 71 and the top surface 51 of the corresponding metal pillar 5 (i.e. the top surface 51 of the metal pillar 5 that constitutes the DC negative terminal or DC positive terminal).

[0022] Please see Figure 4 , it is Figure 1 The diagram shows a top view of the power module of the third embodiment of the power device. Compared to... Figure 1 The power module 2 shown in this embodiment contains only three metal posts 5. These three metal posts 5 respectively constitute a DC negative terminal, a DC positive terminal, and an AC terminal of the power module 2. For example... Figure 4 In the power module 2, the two metal posts 5 on the left side constitute the DC negative terminal and DC positive terminal of the power module 2, respectively, and the metal post 5 on the right side constitutes the AC terminal of the power module 2. Correspondingly, the power module 2b in this embodiment only includes two first current pins 71 and one second current pin 72, and its connection method is similar to that of the first current pins 71 and second current pins 72 in the first embodiment, so it will not be described again here.

[0023] In one embodiment, the power module may not include a first current pin, but only a single second current pin; see [link to relevant documentation]. Figure 5 , it is Figure 1 The diagram shows a top view of the power module of the fourth embodiment of the power device. Compared to... Figure 4The power module 2b shown in this embodiment, and the power module 2c in this embodiment, only contain a single second current pin 72. Its connection method is similar to that of the second current pin 72 in the first embodiment, so it will not be described again here.

[0024] Please see Figure 6 , it is Figure 1 The diagram shows a top view of the power module of the fifth embodiment of the power device. In this embodiment, the width of the second end 712 of a portion of the first current pin 71 (i.e., the upper first current pin 71) is greater than the width of the first end 711, and the width of the second end 722 of the second current pin 72 is greater than the width of the first end 721. For example, the shape of the second end 712 of the first current pin 71 and / or the second end 722 of the second current pin 72 can be rectangular or circular. In this embodiment, the second end 712 of a portion of the first current pin 71 (i.e., the lower first current pin 71) may have a through hole 713 for a screw (not shown) to pass through, so that the first current pin 71 is fixed to another metal post by the screw. Of course, the second end 722 of the second current pin 72 may also have a through hole, which will not be described further here.

[0025] Please see Figure 7 , it is Figure 1 A top view of the power module of the sixth embodiment of the power device shown. Compared to Figure 1 The power module 2 shown in this embodiment further includes a connection part 74, which is connected between the two corresponding first current pins 71, that is, between the two metal pillars 5 that constitute the two DC positive terminals of the power module 2, so as to provide power transmission between the two metal pillars 5.

[0026] In summary, the top surface of the metal pillar of the power device of the present invention is exposed to the surface of the encapsulation material, and the first end of at least one first current pin of each power module is disposed on the top surface of the corresponding metal pillar by welding or sintering, and the second end of the corresponding first current pin of the corresponding power module is disposed on the top surface of the metal pillar of another power module by welding or sintering. Therefore, the power modules of the power device of the present invention can be connected to another power module at any position using the first current pin, making the power device of the present invention more versatile. In addition, the first current pin of the power device of the present invention can be easily replaced, thus improving the overall practicality of the power device.

Claims

1. A power device, wherein, Include: Multiple power modules, each of which includes: A substrate, comprising a metal surface; A chip is disposed on the metal surface; Multiple metal pillars are disposed on the metal surface along a normal direction of the substrate, and each metal pillar includes a top surface and a pillar body; An encapsulation material covers the substrate, the chip, and the plurality of metal pillars, wherein the body of each metal pillar is completely covered by the encapsulation material, and the top surface of each metal pillar is exposed on a surface of the encapsulation material. as well as A plurality of first current pins, wherein each first current pin includes a first terminal and a second terminal; At least one of the first current pins of each power module is disposed on the top surface of the corresponding metal pillar by welding or sintering, and the second end of the corresponding first current pin of the corresponding power module is disposed on the top surface of the metal pillar corresponding to another power module by welding or sintering.

2. The power device of claim 1, wherein, Each power module also includes a solder pad attached between the first end of the corresponding first current pin and the top surface of the corresponding metal post.

3. The power device of claim 1, wherein, The first end of each first current pin of each power module is directly attached to the top surface of the corresponding metal post.

4. The power device of claim 1, wherein, Each of the power modules' metal pillars also includes a bottom surface disposed opposite to the top surface, wherein each power module also includes a pillar solder disposed between the bottom surface of the corresponding metal pillar and the metal surface of the substrate, and / or between the chip and the metal surface of the substrate.

5. The power device of claim 1, wherein, Each power module also includes a metal wire bonded between the side of the chip facing the substrate and the metal surface of the substrate.

6. The power device of claim 1, wherein, The thickness of each first current pin of each power module is less than the thickness of the corresponding metal pillar along the normal direction of the substrate.

7. The power device according to claim 1, wherein, The width of the second end of each of the first current pins of each power module is greater than or equal to the width of the first end of the corresponding first current pin.

8. The power device according to claim 1, wherein, Each of the first current pins of each power module has a through hole at its second end.

9. The power device according to claim 1, wherein, Each power module also includes a connector that connects between the corresponding two first current pins.

10. The power device according to claim 1, wherein, Each power module also includes a second current pin, which includes a first end and a second end, wherein the first end of the second current pin is disposed on the top surface of the corresponding metal pillar by welding or sintering, and the second end of the second current pin is disposed on a system connection terminal of a system by welding or sintering.

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