Power module

Abstract

Disclosed in the present invention is a power module. In some embodiments, the power module comprises a first circuit board, a second circuit board, a power chip and an encapsulation body, wherein the first circuit board, the second circuit board, and the power chip are disposed inside the encapsulation body; the power chip is disposed between the first circuit board and the second circuit board; and the second circuit board is provided with a metal heat sink exposed from the encapsulation body and an insulating heat-conducting member for establishing a heat conduction path between the power chip and the metal heat sink. The present invention can achieve fast heat dissipation of the power chip while achieving the miniaturization of the power module.

Description

Power Module Technical Field

[0001] This invention relates to the field of power modules. Background Technology

[0002] Power modules with power chips such as IGBTs (Insulated Gate Bipolar Transistors) and / or MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) are widely used in various electronic / electrical devices. These power modules typically generate a large amount of heat during operation, requiring high heat dissipation performance. Furthermore, as electronic / electrical products trend towards lighter and smaller designs, miniaturized power modules with high heat dissipation capabilities have become a key industry goal. Summary of the Invention

[0003] A first aspect of the present invention discloses a power module, including a first circuit board, a second circuit board, a power chip, and a package; wherein the first circuit board, the second circuit board, and the power chip are disposed in the package, the power chip is disposed between the first circuit board and the second circuit board, and the second circuit board is provided with a metal heat sink exposed from the package and an insulating heat-conducting element for establishing a heat conduction path between the power chip and the metal heat sink.

[0004] In the above technical solution, the heat generated by the power chip can be quickly conducted to the metal heat sink through the insulating thermal conductive component, so that the power module has better heat dissipation performance; electronic components can be set on the first circuit board and / or the second circuit board, and these electronic components can be set together with the circuit board and the power chip in the package, which is conducive to the miniaturization of the package module.

[0005] Furthermore, the first circuit board includes a first insulating substrate, a first circuit layer, and a second circuit layer, the first circuit layer and the second circuit layer being respectively disposed on opposite sides of the first insulating substrate, and the first circuit layer being connected to the power chip.

[0006] Furthermore, the second circuit board includes a second insulating substrate, a third circuit layer, the metal heat sink, and the insulating thermal conductive component. The third circuit layer and the metal heat sink are respectively disposed on opposite sides of the second insulating substrate. The third circuit layer is connected to the power chip. The insulating thermal conductive component penetrates the second insulating substrate and connects the third circuit layer and the metal heat sink.

[0007] Furthermore, the power chip has a first side and a second side disposed opposite to each other, and chip electrodes are respectively provided on the first side and the second side. The chip electrode on the first side is connected to the first circuit layer, and the chip electrode on the second side is connected to the third circuit layer.

[0008] Furthermore, the power module also includes electronic components disposed on the first circuit board and / or the second circuit board.

[0009] Furthermore, the insulating and heat-conducting component is ceramic.

[0010] Furthermore, the power module is provided with multiple pins, and the multiple pins and the metal heat sink are respectively located on opposite sides of the power module to achieve effective separation of the power module's electrical and thermal properties.

[0011] Furthermore, the power module is also provided with a heat sink connected to the metal heat sink to further enhance the heat dissipation performance of the power module.

[0012] A second aspect of the present invention discloses a power module, including a circuit board, a power chip, and a package; wherein the circuit board and the power chip are disposed in the package, and a metal heat sink connected to the power chip is provided on one side of the package, the metal heat sink including a sputtered metal layer and a thickened metal layer disposed on the sputtered metal layer.

[0013] In the above technical solution, the power chip is connected to the sputtered metal layer of the metal heat sink. Compared with directly soldering the metal heat sink onto the power chip, the sputtered metal layer helps to reduce the connection stress between the metal heat sink and the power chip, prevent damage to the power chip, and improve product yield.

[0014] Furthermore, the power module is provided with multiple pins, and the multiple pins and the metal heat sink are respectively located on opposite sides of the power module to achieve effective separation of the power module's electrical and thermal properties.

[0015] Furthermore, the power module also includes electronic components disposed on the circuit board.

[0016] Furthermore, the power module also includes a heat sink connected to the metal heat sink. To more clearly illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0017] Figure 1 is a structural schematic diagram of embodiment 1 of the power module of the present invention;

[0018] Figure 2 is a structural schematic diagram of embodiment 2 of the power module of the present invention;

[0019] Figure 3 is a structural schematic diagram of the power module of embodiment 3 of the present invention;

[0020] Figure 4 is a structural schematic diagram of embodiment 4 of the power module of the present invention.

[0021] It should be noted that, in order to clearly illustrate the structure to be expressed, different parts in the accompanying drawings may not be depicted to the same scale. Therefore, unless explicitly stated otherwise, the contents of the accompanying drawings do not constitute a limitation on the size and scale of the various parts of the power integrated module. Detailed Implementation

[0022] Numerous specific details are set forth in the following description to provide a thorough understanding of the invention; however, the invention may also be practiced in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0023] Example 1

[0024] Referring to Figure 1, the power module of Embodiment 1 includes a first circuit board 11, a second circuit board 21, a power chip 30, a package 101, and a heat sink 40. The first circuit board 11, the second circuit board 21, and the power chip 30 are disposed within the package 101, with the power chip 30 positioned between and connected to the first circuit board 11 and the second circuit board 21. The package 101 can be a resin or plastic package, and can be obtained by injection molding. The first circuit board 11 and the second circuit board 21 may be partially exposed from the package 101.

[0025] Specifically, the first circuit board 11 is a circuit board with conductive lines on both sides, including a first insulating substrate 111, a first circuit layer 112 and a second circuit layer 113. The first circuit layer 112 and the second circuit layer 113 are respectively disposed on opposite sides of the first insulating substrate 111, and the first circuit layer 112 and the second circuit layer 113 are electrically connected through an interlayer interconnection portion 114 (e.g., a conductive via) penetrating the first insulating substrate 111.

[0026] The second circuit board 21 includes a second insulating substrate 211, a third circuit layer 212, a metal heat sink 213, and an insulating heat-conducting component 214. The third circuit layer 212 and the metal heat sink 213 are respectively disposed on opposite sides of the second insulating substrate 211. Exemplarily, both the first insulating substrate 111 and the second insulating substrate 211 can be FR-4 substrates, but the present invention is not limited thereto.

[0027] The insulating thermally conductive element 214 is configured to penetrate the second insulating substrate 211 and connect the third circuit layer 212 and the metal heat sink 213, thereby establishing a heat conduction path between the power chip 30, the third circuit layer 212, and the metal heat sink 213. The insulating thermally conductive element 214 and the power chip 30 at least partially overlap in the thickness direction of the second circuit board 21 to increase the heat transfer interface between the power chip 30 and the insulating thermally conductive element 214. Preferably, the insulating thermally conductive element 214 is ceramic, such as aluminum nitride ceramic.

[0028] The metal heat sink 213 is configured to be exposed from one side of the package 101, and the heat sink 40 is connected to the metal heat sink 213. The metal heat sink 213 may be copper foil. The heat sink 40 may be a finned heat sink, a staggered heat sink, a water-cooled heat sink, or a heat sink with an evaporation-condensation chamber, etc., and the present invention does not limit it.

[0029] In Embodiment 1, the power chip 30 has a first side and a second side disposed opposite to each other. The first side and the second side are provided with chip electrodes that are respectively connected to the first circuit layer 112 and the third circuit layer 212. Specifically, the first side of the power chip 30 is provided with a gate G and a source S connected to the first circuit layer 112, and the second side of the power chip 30 is provided with a drain D connected to the third circuit layer 212.

[0030] The power chip 30 can be an IGBT or a MOSFET chip, and there can be one or more of them. For example, the power chip 30 includes a first power chip 30a and a second power chip 30b. The drains D of both the first power chip 30a and the second power chip 30b are connected to the third circuit layer 212, and the gates G and sources S are both connected to the first circuit layer 112. A conductive element 104, such as a copper block, is provided between the first circuit layer 112 and the third circuit layer 212. The conductive element 104 is used to form an electrical connection between the drain D of the first power chip 30a and the source S of the second power chip 30b.

[0031] As shown in Figure 1, the power module has multiple pins 102 that are electrically connected to the power chip 30 and enable internal and external electrical connections within the module. The multiple pins 102 and the metal heat sink 213 are located on opposite sides of the power module. Exemplarily, the multiple pins 102 include a source pin 102a, a gate pin 102b, and a drain pin (not shown in the figure). The pins 102 are electrically connected to the first circuit board 11 or the second circuit board 21 through vias 103 within the package 101, and subsequently to the power chip 30. For example, source pin 102a is electrically connected to the first circuit board 11 / second circuit layer 113 through a corresponding via 103a, and is electrically connected to the source S of the first power chip 30a through the first circuit board 11. Gate pin 102b is electrically connected to the first circuit board 11 / second circuit layer 113 through a corresponding via 103b, and is electrically connected to the gate G of the second power chip 30b through the first circuit board 11. Similarly, drain pin is electrically connected to the second circuit board 21 / third circuit layer 212 through a corresponding via (not shown in the figure) disposed in the package 101, and is electrically connected to the drain D of the second power chip 30b through the second circuit board 21 / third circuit layer 212. The via corresponding to the drain pin can be configured to pass through the inside of the first circuit board 11 or to pass through the side of the first circuit board 11.

[0032] In this invention, the via 103 and the pin 102 can be obtained by the following method: First, holes for making the via 103 are machined from the surface of the package 101 facing away from the metal heat sink 213 by means of, for example, laser drilling, to achieve high-precision via fabrication; then, a metal underlayer is formed on the hole wall and the surface of the package 101 facing away from the metal heat sink 213 by sputtering; then, surface layout lines (RDL) are performed on the metal underlayer on the surface of the package 30 to form a pattern corresponding to the pin 102; finally, surface electroplating is performed on the patterned metal underlayer so that the via 103 is completely filled with a metal material (e.g., copper and / or silver) and a pin 102 of a predetermined thickness is obtained.

[0033] Furthermore, the power module also includes electronic components disposed on the first circuit board 11, such as a decoupling capacitor 105 and a chip driver 106 connected to the second circuit layer 113. Other electronic components, such as resistors, inductors, and bypass capacitors, may also be disposed on the first circuit board 11 and / or the second circuit board 21.

[0034] Example 2

[0035] As shown in Figure 2, the power module of Embodiment 2 includes a first circuit board 11, a power chip, and a package 101. The first circuit board 11 is a circuit board with conductive lines on both sides, including a first insulating substrate 111, a first wiring layer 112, and a second wiring layer 113. The first wiring layer 112 and the second wiring layer 113 are respectively disposed on opposite sides of the first insulating substrate 111, and are electrically connected to each other through interlayer interconnects 114 (e.g., conductive vias) penetrating the first insulating substrate 111. The package 101 can be a resin or plastic package.

[0036] The power chip can be an IGBT or MOSFET chip, and there can be one or more of them. For example, the power chip includes a first power chip 201 and a second power chip 202; wherein one surface of the first power chip 201 and the second power chip 202 has a drain D, a source S, and a gate G, and the opposite surface has a heat-conducting pad TP exposed from the package 10. The drain D, source S, and gate G are connected to the first circuit layer 112 of the first circuit board 11, and the surface of the package 101 exposing the heat-conducting pad TP is provided with a metal heat sink 105. Further, the metal heat sink 105 may be connected to a heat sink.

[0037] In Example 2, the heat sink 105 can be obtained by the following method: First, a sputtered metal layer 1051 connected to the heat conduction pad TP is formed on the surface of the package 30 facing away from the circuit board 10 by sputtering. Then, a thickened metal layer 1052 is formed on the sputtered metal layer 1051 to obtain a metal heat sink 105 of a predetermined thickness.

[0038] The first power chip 201 and the second power chip 202 are connected to the sputtered metal layer 1051 of the metal heat sink 105. Compared with directly welding the metal heat sink to the heat conduction pad TP of the first power chip 201 and the second power chip 202, the sputtered metal layer 1051 helps to reduce the connection stress between the metal heat sink 105 and the first power chip 201 and the second power chip 202, prevent damage to the first power chip 201 and the second power chip 202, and improve the product yield.

[0039] Furthermore, the power module also includes multiple pins 102 electrically connected to the first power chip 201 or the second power chip 202. The multiple pins 102 and the metal heat sink 105 are located on opposite sides of the power module. The pins 102 are connected to the first circuit board 11 / second circuit layer 113 through through holes 103 provided in the package 101, and are thus electrically connected to the first power chip 201 or the second power chip 202.

[0040] Further details regarding Example 2 can be found in Example 1 and will not be repeated here.

[0041] Example 3

[0042] The main difference between Embodiment 3 and Embodiment 1 lies in the connection structure between pin 102 and the first circuit board 11. The following only describes the differences between the two. As shown in Figure 3, in Embodiment 3, pin 102 is electrically connected to the first circuit board 11 / first circuit layer 113 via a conductive portion 203 disposed on the side of the package 101 (i.e., the surface where the package 101 connects to the side wall of the first circuit board 11). Specifically, the side of the package 101 has a groove (not shown), the conductive portion 203 is disposed within this groove, and is exposed to the outside of the package 101.

[0043] Example 4

[0044] The main difference between Embodiment 4 and Embodiment 2 lies in the connection structure between pin 102 and the first circuit board 11. As shown in Figure 4, in Embodiment 4, pin 102 is electrically connected to the first circuit board 11 / first circuit layer 113 through a conductive portion 203 disposed on the side of the package 101. The package 101 has a groove (not shown) on its side, the conductive portion 203 is disposed within this groove, and is exposed outside the package 101.

[0045] In embodiments 3 and 4, the conductive portion 203 can also be part of the pin 102, that is, the pin 102 includes the conductive portion 203. Additionally, the pin 102 exposed on the surface of the package 101 can be recessed into or protrude from the surface of the package 101, or it can be configured to be flush with the surface of the package 101. Preferably, the pin 102 is configured not to extend beyond the surface of the package 101 (including the side surface of the package 101) to further promote the miniaturization of the power module.

[0046] In this invention, the pins and the metal heat sink are located on opposite sides of the power module. When the power module is working, the heat generated by the power chip is mainly conducted from the side where the metal heat sink is located, so as to achieve effective separation of electrothermal energy and heat, which helps to reduce the impact of heat on the electronic components in the package and the mounting board of the power module.

[0047] It should be noted that, for the sake of simplicity, some identical descriptions in the different embodiments described above have been omitted. Unless there are contradictions or exclusions, the different embodiments disclosed above can be referenced, consulted, or combined with each other, and the technical features / components of different embodiments can also be combined and / or substituted with each other.

[0048] While the present invention has been described above through embodiments, it should be understood that the above embodiments are only used to exemplify possible implementations of the present invention and should not be construed as limiting the scope of protection of the present invention. Any equivalent substitutions or variations made by those skilled in the art in accordance with the present invention should also be covered by the scope of protection defined by the claims of the present invention.

Claims

1. A power module, characterized by: The power module includes a first circuit board, a second circuit board, a power chip, and a package; wherein the first circuit board, the second circuit board, and the power chip are disposed within the package, the power chip is disposed between the first circuit board and the second circuit board, and the second circuit board has a metal heat sink exposed from the package and an insulating heat-conducting component for establishing a heat conduction path between the power chip and the metal heat sink.

2. The power module of claim 1, characterized in that: The first circuit board includes a first insulating substrate, a first circuit layer and a second circuit layer, the first circuit layer and the second circuit layer are respectively disposed on opposite sides of the first insulating substrate, and the first circuit layer is connected to the power chip.

3. The power module of claim 2, characterized in that: The second circuit board includes a second insulating substrate, a third circuit layer, the metal heat sink, and the insulating thermal conductive component. The third circuit layer and the metal heat sink are respectively disposed on opposite sides of the second insulating substrate. The third circuit layer is connected to the power chip, and the insulating thermal conductive component penetrates the second insulating substrate and connects the third circuit layer and the metal heat sink.

4. The power module of claim 3, characterized in that: The power chip has a first side and a second side arranged opposite to each other. The first side and the second side are respectively provided with chip electrodes. The chip electrode on the first side is connected to the first circuit layer, and the chip electrode on the second side is connected to the third circuit layer.

5. The power module according to claim 1, characterized in that: The power module also includes electronic components disposed on the first circuit board and / or the second circuit board.

6. The power module according to claim 1, characterized in that: The insulating and heat-conducting component is made of ceramic.

7. The power module according to claim 1, characterized in that: The power module has multiple pins, and the multiple pins and the metal heat sink are located on opposite sides of the power module.

8. The power module according to claim 1, characterized in that: The power module is also equipped with a heat sink connected to the metal heat sink.

9. A power module, characterized in that: The power module includes a circuit board, a power chip, and a package; wherein the circuit board and the power chip are disposed in the package, and a metal heat sink connected to the power chip is provided on one side of the package, the metal heat sink including a sputtered metal layer and a thickened metal layer disposed on the sputtered metal layer.

10. The power module according to claim 9, characterized in that: The power module has multiple pins, and the multiple pins and the metal heat sink are located on opposite sides of the power module.

11. The power module according to claim 9, characterized in that: The power module also includes electronic components mounted on the circuit board.

12. The power module according to claim 9, characterized in that: The power module is also equipped with a heat sink connected to the metal heat sink.

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