Directional heat dissipation power chip packaging module

Abstract

The utility model discloses a power chip packaging module with directional heat dissipation. The packaging module of the embodiment comprises a ceramic substrate, a circuit board and a power chip packaged between the circuit board and the ceramic substrate. Wherein the circuit board comprises an insulating substrate provided with a vacuum cavity, a conducting strip, an inner side conducting circuit and an outer side conducting circuit, the inner side conducting circuit is arranged on the inner side surface of the insulating substrate, the outer side conducting circuit is arranged on the outer side surface of the insulating substrate, and the conducting strip is embedded in the insulating substrate and exposed from the inner side surface of the insulating substrate; the vacuum cavity is located between the conducting strip and the outer side surface of the insulating substrate in the thickness direction of the circuit board. According to the utility model, the vacuum cavity is arranged in the insulating substrate of the circuit board, so that heat of the power chip is prevented from being conducted to the outer side surface of the insulating substrate, and the influence of the heat on electronic elements / assemblies attached to the circuit board is reduced.

Description

Technical Field

[0001] This utility model relates to the field of power chip packaging; more specifically, it relates to a power chip packaging module with directional heat dissipation. Background Technology

[0002] Power modules, including power chips such as IGBTs and / or MOSFETs, are widely used in various power electronic devices. Because these power chips generate a significant amount of heat during operation, the packaging module must possess excellent heat dissipation performance to enable rapid heat dissipation. Furthermore, other electronic components such as capacitors and driver components are attached to the power module. To minimize the impact of the heat generated by the power chip on these other electronic components, it is desirable to prevent the heat generated by the power chip from being conducted to other electronic components on the power module as much as possible. Utility Model Content

[0003] The main objective of this invention is to provide a power chip packaging module that enables directional heat dissipation of the power chip, thereby reducing the impact of the heat generated by the power chip on other electronic components / assemblies.

[0004] To achieve the aforementioned main objectives, this utility model discloses a power chip packaging module, including a ceramic substrate, a circuit board, and a power chip packaged between the circuit board and the ceramic substrate; wherein, the circuit board includes an insulating substrate with a vacuum cavity, a conductive sheet, an inner conductive line, and an outer conductive line, the inner conductive line being disposed on the inner surface of the insulating substrate, the outer conductive line being disposed on the outer surface of the insulating substrate, the conductive sheet being embedded in the insulating substrate and exposed from the inner surface of the insulating substrate, and the vacuum cavity being located between the conductive sheet and the outer surface of the insulating substrate in the thickness direction of the circuit board.

[0005] Furthermore, the insulating substrate has multiple support portions disposed within the vacuum cavity.

[0006] Furthermore, the inner surface of the ceramic substrate is provided with a conductive portion, and the outer surface is provided with a metal heat dissipation layer; the first side of the power chip is electrically connected to the inner conductive line and the conductive sheet, and the second side of the power chip relative to the first side is electrically connected to the conductive portion.

[0007] According to a specific embodiment of the present invention, the power chip has a source and a gate on a first side, and a drain on a second side. The source and the gate are electrically connected to the conductive sheet and the inner conductive line, respectively, and the drain is electrically connected to the conductive part.

[0008] Preferably, a heat-conducting block is provided between the ceramic substrate and the conductive sheet, and the opposite sides of the heat-conducting block are thermally connected to the conductive sheet and the ceramic substrate, respectively.

[0009] According to a specific embodiment of the present invention, the heat-conducting block is a ceramic heat-conducting block, and the opposite sides of the ceramic heat-conducting block are thermally connected to the conductive sheet and the conductive part, respectively.

[0010] According to a specific embodiment of the present invention, the conductive part includes a first conductive layer and a second conductive layer stacked together, and the second conductive layer and the first conductive layer are welded together.

[0011] Preferably, the thickness of the second conductive layer is greater than the thickness of the first conductive layer.

[0012] According to a specific embodiment of the present invention, the circuit board further includes conductive pins, which are disposed at the edge of the circuit board.

[0013] According to a specific embodiment of this utility model, the power chip is an IGBT chip.

[0014] The technical solution of this utility model has the following beneficial effects:

[0015] In this invention, the power chip is packaged between the circuit board and the ceramic substrate. A vacuum cavity is provided inside the insulating substrate of the circuit board to prevent the heat of the power chip from being conducted to the outer surface of the insulating substrate. This allows the heat generated by the power chip to be dissipated in a directional manner through the ceramic substrate, thereby reducing the impact of heat on electronic components / assemblies attached to the outer surface of the insulating substrate / circuit board.

[0016] Furthermore, the heat generated by the power chip can not only be conducted from its second side to the ceramic substrate, but also, due to the presence of a heat-conducting block between the conductive sheet and the ceramic substrate, the heat generated by the power chip can be conducted from its first side to the ceramic substrate through the conductive sheet and the heat-conducting block, thus achieving rapid heat dissipation of the power chip.

[0017] To more clearly illustrate the purpose, technical solution, and advantages of this utility model, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the power module in Example 1;

[0019] Figure 2 This is an exploded view of the power module in Example 1;

[0020] Figure 3This is a schematic diagram of the overall structure of the power module in Example 2. Detailed Implementation

[0021] Many specific details are set forth in the following description to provide a full understanding of the present invention; however, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0022] Example 1

[0023] Combination Figure 1 and Figure 2 As shown, the power chip packaging module of Embodiment 1 includes a ceramic substrate 200, a circuit board 300, and a power chip 100 packaged between the circuit board 300 and the ceramic substrate 200; wherein, the space between the ceramic substrate 200 and the circuit board 300 is filled with an encapsulation material 110, such as resin, for encapsulating the power chip 100.

[0024] The inner surface of the ceramic substrate 200 is provided with one or more conductive portions 230, and the outer surface is provided with a metal heat dissipation layer 220. The conductive portions 230 and the metal heat dissipation layer 220 are electrically insulated from each other by a ceramic core board 210. The conductive portions 230 are used to transmit large currents through the power chip 100 and include a first conductive layer 231 and a second conductive layer 232 stacked together. The first conductive layer 231 and the second conductive layer 232 are welded together to reduce the internal stress of the conductive portions 230 and the ceramic substrate 200. The first conductive layer 231, the second conductive layer 232, and the metal heat dissipation layer 230 can all be copper foil layers, but are not limited thereto. For example, the surfaces of the second conductive layer 232 and the metal heat dissipation layer 230 may also be provided with protective layers such as nickel and / or gold layers.

[0025] The conductive portion 230 has a patterned structure, which can be obtained by the following method: First, a first conductive layer 231 with a patterned structure is obtained through an etching step; then, a second conductive layer 232, which is processed into a corresponding conductive pattern, is soldered onto the first conductive layer 231. In this way, the soldering material between the first conductive layer 231 and the second conductive layer 232 can buffer the thermal stress generated by the first conductive layer 231 and the second conductive layer 232 during thermal cycling, thereby reducing the stress at the interface between the first conductive layer 231 / conductive portion 230 and the ceramic core plate 210, and avoiding or reducing defects such as cracks and warping in the ceramic substrate 200.

[0026] Preferably, the thickness of the second conductive layer 232 is greater than the thickness of the first conductive layer 231. Since the first conductive layer 231 is fabricated by etching, using a thinner first conductive layer 231 reduces the etching depth and improves the pattern accuracy of the first conductive layer 231. The thicker second conductive layer 232 can be fabricated by methods such as laser cutting or mechanical punching to ensure its pattern accuracy. Therefore, the pattern accuracy of the conductive portion 230 can be well controlled.

[0027] The circuit board 300 includes an insulating substrate 310, a conductive sheet 320, inner conductive lines 342, and outer conductive lines 341. The insulating substrate 310 has a laminated structure comprising a multilayer insulating core board 311 (e.g., an FR-4 core board) and an insulating adhesive sheet 312. The conductive sheet 320 is embedded in the insulating substrate 310 and exposed from its inner surface. The inner conductive lines 342 are disposed on the inner surface of the insulating substrate 310, and the outer conductive lines 341 are disposed on the outer surface of the insulating substrate 310. Further, the circuit board 300 also includes inner layer conductive lines 343 disposed within the insulating substrate 310. The specific number of layers of the inner layer conductive lines 343 can be designed as needed, and this invention does not limit this. Different conductive line layers of the circuit board 300 can be electrically connected through interlayer interconnecting holes (not shown in the figure), such as conductive vias.

[0028] The thickness of the conductive sheet 320 is greater than the thickness of the inner conductive line 342, used to transmit a larger current through the power chip 100. A first side of the power chip 100 is electrically connected to the inner conductive line 342 and the conductive sheet 320, and a second side of the power chip 100 relative to the first side is electrically connected to the conductive portion 230 of the ceramic substrate 200. The surfaces of the conductive sheet 320 and the inner conductive line 342 used for connecting the power chip 100 are preferably substantially flush to facilitate soldering connections of the power chip 100. The conductive sheet 320 may have pins protruding outside the circuit board 300.

[0029] For example, the power chip 100 is an IGBT chip. The first side of the power chip 100 has a source and a gate, and the second side has a drain. The source and gate are electrically connected to the conductive sheet 320 and the inner conductive line 342 (e.g., the pad 3421 of the conductive line 342), respectively. The drain is electrically connected to the conductive portion 230 of the ceramic substrate 200. The number of power chips 100 can be multiple, and the specific design can be customized as needed; this invention does not limit this.

[0030] Furthermore, a vacuum cavity 330 is provided within the insulating substrate 310, and the vacuum cavity 330 is disposed between the conductive sheet 320 and the outer surface of the insulating substrate 310. A vacuum / negative pressure state is formed inside the vacuum cavity 330, which can effectively block heat conduction to the outer surface of the insulating substrate 310 / circuit board 300, allowing the heat generated by the power chip 100 to be mainly dissipated through the ceramic substrate 200, thereby reducing the impact of heat on electronic components / assemblies attached to the outer surface of the insulating substrate 310 / circuit board 300. The number of vacuum cavities 330 can be one or more, and this invention does not limit this.

[0031] Specifically, the vacuum cavity 330 can be a negative pressure sealing groove provided in the insulating core board 311, which can be obtained by the following exemplary method: First, a groove is machined in the insulating core board 311a used to form the vacuum cavity 330; then, the multilayer insulating core board 311 including the insulating core board 311a and the insulating adhesive sheet 312 (e.g., a prepreg) are stacked and pressed together to obtain the insulating substrate 310 and seal the groove. At the same time, the groove is evacuated during the pressing process to form a vacuum cavity 330 in a negative pressure state.

[0032] Furthermore, a through hole can be machined on the insulating adhesive sheet 312a located on the opening side of the groove, corresponding to the groove. The size of the through hole is preferably larger than the size of the groove, so as to reduce the flow of resin in the insulating adhesive sheet 312a into the groove during the pressing process.

[0033] As a variation of the above exemplary method, grooves can be machined on the mutually facing surfaces of two adjacent insulating core boards 311, and after the boards are laminated, the grooves on the two adjacent insulating core boards 311 are combined to form a vacuum cavity 330.

[0034] Preferably, the insulating substrate 310 has a plurality of support portions 331 disposed within the vacuum cavity 330. The plurality of support portions 331 may be arranged in a two-dimensional array or radially. The support portions 331 may be part of the insulating core board 311 (e.g., insulating core board 311a) used to form the vacuum cavity 330. The support portions 331 can provide support, improve the flatness of the circuit board 300 surface, and avoid or reduce the occurrence of depressions in the surface area of ​​the circuit board 300 corresponding to the vacuum cavity 330. Furthermore, interlayer interconnecting holes, such as conductive vias, can be formed in the support portions 331 to facilitate electrical connections between the conductive line layers on both sides of the vacuum cavity 330.

[0035] Furthermore, a heat-conducting block 120 is provided between the ceramic substrate 200 and the conductive sheet 320. The heat-conducting block 120 is disposed on the side of the power chip 100. The opposite sides of the heat-conducting block 120 (the upper and lower sides in the figure) are thermally connected to the conductive sheet 320 and the ceramic substrate 200, respectively. The heat generated by the power chip 100 can be conducted not only from its second side to the ceramic substrate 200, but also from its first side through the conductive sheet 320 and the heat-conducting block 120 to the ceramic substrate, so as to achieve rapid heat dissipation.

[0036] In Embodiment 1, the heat-conducting block 120 is a ceramic heat-conducting block, and its opposite sides are thermally connected to the conductive sheet 320 and the conductive part 230, respectively. The surface of the ceramic heat-conducting block that connects to the conductive sheet 320 and the conductive part 230 may be provided with a metal layer, such as a copper foil layer, to facilitate welding connections with the conductive sheet 320 and the conductive part 230.

[0037] Furthermore, the circuit board 300 also includes conductive pins 344, which can be located at the edge of the circuit board 300 and electrically connected to conductive lines on the circuit board 300. In use, electronic components / assemblies (e.g., the drive assembly of the power chip 100) can be attached to the outer surface of the circuit board 300 and electrically connected to the conductive pins 344. Since the vacuum cavity 330 provides thermal insulation, the impact of heat on the electronic components / assemblies attached to the outer surface of the insulating substrate 310 / circuit board 300 can be reduced.

[0038] Example 2

[0039] The difference between Example 2 and Example 1 is that the heat-conducting block 120 in Example 2 is a metal heat-conducting block.

[0040] like Figure 3 As shown, in Embodiment 2, the inner surface of the ceramic substrate 200 / ceramic core board 210 has a metal heat-conducting portion 240 separated from the conductive portion 230. One side of the metal heat-conducting block / heat-conducting block 120 is thermally connected (e.g., welded) to the conductive sheet 320, and the other side of the metal heat-conducting block / heat-conducting block 120 is thermally connected (e.g., welded) to the metal heat-conducting portion 240. The metal heat-conducting portion 240 preferably has the same thickness as the conductive portion 230 and can be manufactured using the same method as the conductive portion 230.

[0041] Although the present invention has been described above through embodiments, it should be understood that the above embodiments are only used to exemplarily describe the possible implementations of the present invention, and should not be construed as limiting the scope of protection of the present invention. All equivalent changes made by those skilled in the art in accordance with the present invention should also be covered by the scope of protection of the claims of the present invention.

Claims

1. A power chip packaging module with directional heat dissipation, comprising a ceramic substrate, a circuit board, and a power chip packaged between the circuit board and the ceramic substrate; characterized in that: The circuit board includes an insulating substrate with a vacuum cavity, a conductive sheet, an inner conductive line, and an outer conductive line. The inner conductive line is disposed on the inner surface of the insulating substrate, and the outer conductive line is disposed on the outer surface of the insulating substrate. The conductive sheet is embedded in the insulating substrate and exposed from the inner surface of the insulating substrate. The vacuum cavity is located between the conductive sheet and the outer surface of the insulating substrate in the thickness direction of the circuit board.

2. The power chip packaging module with directional heat dissipation according to claim 1, characterized in that: The insulating substrate has multiple support portions disposed within the vacuum cavity.

3. The power chip packaging module with directional heat dissipation according to claim 1, characterized in that: The inner surface of the ceramic substrate is provided with a conductive part, and the outer surface is provided with a metal heat dissipation layer; the first side of the power chip is electrically connected to the inner conductive line and the conductive sheet, and the second side of the power chip relative to the first side is electrically connected to the conductive part.

4. The power chip packaging module with directional heat dissipation according to claim 3, characterized in that: The power chip has a source and a gate on its first side, and a drain on its second side. The source and the gate are electrically connected to the conductive sheet and the inner conductive line, respectively, and the drain is electrically connected to the conductive part.

5. The power chip packaging module with directional heat dissipation according to claim 3, characterized in that: A heat-conducting block is provided between the ceramic substrate and the conductive sheet, and the opposite sides of the heat-conducting block are thermally connected to the conductive sheet and the ceramic substrate, respectively.

6. The power chip packaging module with directional heat dissipation according to claim 5, characterized in that: The heat-conducting block is a ceramic heat-conducting block, and the opposite sides of the ceramic heat-conducting block are thermally connected to the conductive sheet and the conductive part, respectively.

7. The power chip packaging module with directional heat dissipation according to claim 3, characterized in that: The conductive part includes a first conductive layer and a second conductive layer stacked together, and the second conductive layer is welded to the first conductive layer.

8. The power chip packaging module with directional heat dissipation according to claim 7, characterized in that: The thickness of the second conductive layer is greater than the thickness of the first conductive layer.

9. The power chip packaging module with directional heat dissipation according to claim 1, characterized in that: The circuit board also includes conductive pins, which are located at the edge of the circuit board.

10. The power chip packaging module with directional heat dissipation according to claim 1, wherein, The power chip is an IGBT chip.

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