Power device
Patent Information
- Application Number
- TW114104982
- Authority / Receiving Office
- TW · TW
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-02-11
- Publication Date
- 2026-08-16
- Estimated Expiration
- 2045-02-10
AI Technical Summary
Traditional power devices have limited applicability as they can only connect to adjacent systems using leadframes of individual power modules, and repositioning or redesigning leadframes is costly, complicating practicality.
The power device design exposes the top surface of metal pillars within an encapsulation material, allowing first current pins of each power module to be soldered or sintered to the top surface of another power module, enabling connections at any location and facilitating easy replacement of pins.
This design enhances the versatility and practicality of power devices by allowing connections between power modules at any position and simplifying the replacement of first current pins, improving overall applicability and reducing repositioning costs.
Smart Images
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Abstract
Description
[Technical Field]
[0001] This case relates to a power device, and more particularly to a power device with high practicality. [Previous Technology]
[0002] A power device comprises multiple power modules, each with a leadframe for transmitting signals and high current. Typically, the leadframes of power modules are sealed with adhesive, exposing some terminals on the side of the adhesive for connection to the system. However, traditional power devices can only connect to adjacent systems using the leadframe corresponding to a single power module; they cannot connect individual power modules to adjacent power modules or different power devices to each other. Therefore, traditional power devices have limited applicability. Furthermore, because the leadframes of each power module in a traditional power device must be sealed in adhesive, the cost of repositioning or redesigning the leadframes is high, resulting in poor 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, 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 corresponding metal pillar of another power module by welding or sintering. Therefore, the power module of the power device of this invention can be connected to another power module at any position using the first current pin, making the power device of this invention more applicable. In addition, the first current pin of the power device of this invention can be replaced more conveniently, thus improving the overall practicality of the power device.
[0005] To achieve the above objectives, one embodiment of this invention is a power device comprising multiple power modules. Each power module includes a substrate, a wafer, multiple metal pillars, encapsulation material, and multiple first current pins. The substrate includes a metal surface. The wafer 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 wafer, 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.
Implementation Method
[0006] Some typical embodiments embodying the features and advantages of this case will be described in detail in the following description. It should be understood that this case can have various variations in different forms, all of which do not depart from the scope of this case, and the descriptions and drawings therein are essentially for illustrative purposes and not for limiting this case.
[0007] Please refer to Figures 1 and 2, where Figure 1 is a top view of the power device of this invention, and Figure 2 is a cross-sectional view of the power module of the first embodiment of the power device shown in Figure 1. As shown, the power device 1 of this embodiment is connected to the system 10 and includes multiple power modules 2, such as the three power modules 2 shown in Figure 1, wherein the three power modules 2 are interconnected, and the connection method will be described later. As shown in Figure 2, each power module 2 includes a substrate 3, a chip 4, multiple metal pillars 5, a packaging material 6, three first current pins 71, second current pins 72, and metal wire bonding 8. The substrate 3 includes a metal surface 31. The chip 4 is disposed on the metal surface 31 of the substrate 3. As shown in Figure 2, each metal pillar 5 can constitute a signal pin or a current pin. For example, the two metal pillars 5 on the left and right sides of Figure 2 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 wafer 4. Each metal pillar 5 includes a top surface 51, a bottom surface 52 and a pillar body 53. The top surface 51 and the 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 in Figure 1, each power module 2 includes four metal pillars 5. The four metal pillars 5 respectively constitute a DC negative terminal, two DC positive terminals and an AC terminal of the power module 2. For example, in Figure 1, the metal pillar 5 located above the power module 2 constitutes the DC negative terminal of the power module 2, the two metal pillars 5 located on the left and right sides of the power module 2 respectively constitute the two DC positive terminals of the power module 2, and the metal pillar 5 located below the power module 2 constitutes the AC terminal of the power module 2.
[0008] As shown in Figure 2, the encapsulation material 6 covers the substrate 3, the wafer 4 and a plurality of metal pillars 5. In other words, the substrate 3, the wafer 4 and the plurality of metal pillars 5 are encapsulated in the encapsulation material 6, wherein the substrate 3, the wafer 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.
[0009] 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 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 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 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 corresponding to another power module 2 by welding or sintering, 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 welding techniques such as ultrasonic welding or laser welding. 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.
[0010] 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 wafer 4 facing the substrate 3 and the metal surface 31 of the substrate 3 to provide current conduction between the wafer 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 allow 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.
[0011] As can be seen from the above, the top surface 51 of the metal pillar 5 of the power device 1 in this 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 power modules of conventional power devices that can only be connected to adjacent power modules, the power module 2 of the power device 1 in this invention can be connected to another power module 2 at any position using the first current pin 71, making the applicability of the power device 1 in this invention better. In addition, the first current pin 71 of the power device 1 in this invention can be replaced more conveniently, so the overall practicality of the power device 1 is better.
[0012] Please refer to Figure 2. The 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.
[0013] Please refer to Figure 3, which is a cross-sectional structural schematic diagram of the power module of the second embodiment of the power device shown in Figure 1. Compared with the power module 2 shown in Figure 2, the power module 2a of this embodiment further 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 constituting the DC negative terminal or DC positive terminal).
[0014] Please refer to Figure 4, which is a top view of the power module of the third embodiment of the power device shown in Figure 1. Compared with the power module 2 shown in Figure 1, the power module 2b of this embodiment only includes three metal pillars 5. The three metal pillars 5 respectively constitute a DC negative terminal, a DC positive terminal, and an AC terminal of the power module 2. For example, in Figure 4, the two metal pillars 5 on the left side of the power module 2 constitute the DC negative terminal and the DC positive terminal of the power module 2, respectively, and the metal pillar 5 on the right side of the power module 2 constitutes the AC terminal of the power module 2. Correspondingly, the power module 2b of this embodiment only includes two first current pins 71 and one second current pin 72. The connection method is similar to the connection method of the first current pin 71 and the second current pin 72 in the first embodiment, so it will not be described again here.
[0015] In one embodiment, the power module may not include a first current pin, but only a single second current pin. Please refer to Figure 5, which is a top view of the power module of the fourth embodiment of the power device shown in Figure 1. Compared with the power module 2b shown in Figure 4, the power module 2c of this embodiment only includes a single second current pin 72, and 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.
[0016] Please refer to Figure 6, which is a top view of the power module of the fifth embodiment of the power device shown in Figure 1. 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.
[0017] Please refer to Figure 7, which is a top view of the power module of the sixth embodiment of the power device shown in Figure 1. Compared with the power module 2 shown in Figure 1, the power module 2e of this embodiment further includes a connection part 74, which is connected between the corresponding two first current terminals 71, that is, connected between the two metal posts 5 that constitute the two DC positive terminals of the power module 2, so as to provide power transmission between the two metal posts 5.
[0018] In summary, the top surface of the metal pillar of the power device of this 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 module of the power device of this invention can be connected to another power module at any position using the first current pin, making the power device of this invention more applicable. In addition, the first current pin of the power device of this invention can be replaced relatively easily, thus the overall practicality of the power device is better. [Simplified Explanation of the Diagram]
[0019] Figure 1 is a top view of the power device of this invention; Figure 2 is a cross-sectional view of the power module of the first embodiment of the power device shown in Figure 1; Figure 3 is a cross-sectional view of the power module of the second embodiment of the power device shown in Figure 1; Figure 4 is a top view of the power module of the third embodiment of the power device shown in Figure 1; Figure 5 is a top view of the power module of the fourth embodiment of the power device shown in Figure 1; Figure 6 is a top view of the power module of the fifth embodiment of the power device shown in Figure 1; and Figure 7 is a top view of the power module of the sixth embodiment of the power device shown in Figure 1.
Claims
1. A power device comprising: a plurality of power modules, wherein each power module comprises: a substrate having 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 metal pillar comprising a top surface and a pillar body; an encapsulation material covering the substrate, the chip, and the plurality of 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 a surface of the encapsulation material; and a plurality of first current pins, wherein each first current pin comprises a first end and a second end; wherein at least one first current pin of each power module has its first end disposed on the top surface of a corresponding metal pillar by welding or sintering, and the second end of a corresponding first current pin of a corresponding power module is disposed on the top surface of a corresponding metal pillar of another power module by welding or sintering.
2. The power device as claimed in claim 1, wherein each power module further 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 as claimed in 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 as claimed in claim 1, wherein each of the power modules further includes a bottom surface disposed opposite to the top surface, and wherein each of the power modules further includes a column solder disposed between the bottom surface of the corresponding metal column and the metal surface of the substrate, and / or between the wafer and the metal surface of the substrate.
5. The power device as claimed in claim 1, wherein each power module further includes a metal wire bonded between one side of the wafer relative to the substrate and the metal surface of the substrate.
6. The power device as claimed in 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 as claimed in 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 as claimed in claim 1, wherein the second end of each of the first current pins of each power module has a through hole.
9. The power device as claimed in claim 1, wherein each of the power modules further includes a connection portion connected between corresponding two of the first current pins.
10. The power device as claimed in claim 1, wherein each of the power modules further includes a second current pin, the second current pin including 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.