Power module and packaging method thereof

Abstract

The application provides a power module and a packaging method thereof, and relates to the technical field of power modules. The power module comprises a cavity formed by a shell and a first heat dissipation plate. A chip can be arranged in the cavity. The chip can lead current out of the power module through electrode lead-out pieces. A thin insulating layer is arranged in the cavity. The insulating layer is bonded to exposed surfaces in the cavity and surfaces of the electrode lead-out pieces in a cladding manner. After pouring heat-conducting material into the cavity through an opening, a heat-conducting layer formed by the solidified heat-conducting material can better cover the chip and the electrode lead-out pieces with height differences. Thus, a new heat dissipation path can be established through the heat-conducting layer above the first heat dissipation plate. In addition to the first heat dissipation plate at the bottom of the chip, the heat dissipation path can also dissipate heat from the periphery and the top through the heat-conducting layer covering the chip, so that double-sided heat dissipation of the power module is formed, and the heat dissipation performance of the power module is improved.

Description

Technical Field

[0001] This application relates to the field of power module technology, and more specifically, to a power module and its packaging method. Background Technology

[0002] Power modules, used in motor drives or phase conversion, have a wide range of applications. Besides voltage withstand capability, their current handling capacity is also a key development trend. As current increases, the heat generated by the power module also increases. To prevent power modules from becoming inefficient or even damaged due to high temperatures, improving the module's heat dissipation capacity is a crucial development focus.

[0003] To address the high-temperature issue caused by increased current in power modules, the industry is developing dual-sided heat dissipation architectures for new products. Previously, heat dissipation only occurred from the microchip downwards through a bottom heatsink. Current development focuses on dual-sided heat dissipation, establishing a heat dissipation path upwards from the chip, allowing the power module to dissipate heat from both the top and bottom. However, since most power modules use metal wires to conduct current to the outside of the module, and these wires are often much higher than the chips, varying in height and having relatively low strength, they cannot withstand the pressure from the heatsink above, thus limiting the implementation of dual-sided heat dissipation. Summary of the Invention

[0004] The purpose of this application is to address the shortcomings of the prior art by providing a power module and its packaging method to solve the problem of limited double-sided heat dissipation due to the uneven height of metal wires and chips in existing power modules.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0006] One aspect of this application provides a power module, including:

[0007] First heat sink;

[0008] The outer casing is disposed around the periphery of the first heat sink to cooperate with the first heat sink to form an open cavity;

[0009] The chip is mounted on the first heat sink inside the cavity.

[0010] Electrode leads are connected to the chip inside the cavity;

[0011] An insulating layer is applied to the exposed surfaces inside the cavity and to the surfaces of the electrode leads.

[0012] A thermally conductive layer is injected into the cavity through an opening, and the thermally conductive layer is located on the side surface of the insulating layer opposite to the first heat sink.

[0013] Optionally, the insulating layer includes a first sub-insulating layer covering the exposed surfaces inside and outside the cavity and a second sub-insulating layer covering the surface of the electrode lead-out, wherein the thickness of the first sub-insulating layer and the thickness of the second sub-insulating layer are approximately equal.

[0014] Optionally, the surface of the heat-conducting layer facing away from the first heat sink is flat, and a second heat sink is attached to the flat surface.

[0015] Optionally, the thermally conductive layer is a cured metal paste;

[0016] Alternatively, the resistivity of the thermally conductive layer is less than 10. -6 Ωm;

[0017] Alternatively, the thermal conductivity of the heat-conducting layer is greater than 3 W / mK;

[0018] Alternatively, the insulating layer may be made of a mixture of ceramic and resin.

[0019] Alternatively, the resistivity of the insulating layer is greater than 10. 6 Ωm.

[0020] Optionally, the electrode leads can be metal wires or metal sheets.

[0021] Optionally, a substrate is provided between the chip and the first heat sink, and the chip is connected to the casing or substrate via electrode leads.

[0022] Another aspect of this application provides a power module packaging method, the method comprising:

[0023] Provide chips;

[0024] The chip is mounted on the first heat sink;

[0025] A housing is provided around the periphery of the first heat sink so that the housing cooperates with the first heat sink to form a cavity with an opening, and the chip is located in the cavity;

[0026] Electrode leads are provided on the surface of the chip;

[0027] Insulating material is added into the cavity through the opening;

[0028] Remove the insulating material covering the exposed surfaces inside the cavity and the surfaces of the electrode leads, and then cure to obtain an insulating layer;

[0029] Thermally conductive material located on the side of the insulating layer away from the first heat sink is poured into the cavity through the opening and then cured to obtain a thermally conductive layer.

[0030] Optionally, the insulating layer includes a first sub-insulating layer covering the exposed surfaces inside and outside the cavity and a second sub-insulating layer covering the surface of the electrode lead-out, wherein the thickness of the first sub-insulating layer and the thickness of the second sub-insulating layer are approximately equal.

[0031] Optionally, the thermally conductive layer is obtained by injecting a thermally conductive material located on the side of the insulating layer opposite to the first heat sink into the cavity through the opening and then curing it.

[0032] Thermally conductive material is injected into the cavity through the opening, and the thermally conductive material is located on the side of the insulating layer away from the first heat sink.

[0033] A second heat sink is provided on the side of the thermally conductive material that is away from the first heat sink.

[0034] The thermally conductive material is cured to obtain a thermally conductive layer, so that the thermally conductive layer is bonded to the second heat sink.

[0035] Optionally, the thermally conductive layer is obtained by injecting a thermally conductive material located on the side of the insulating layer opposite to the first heat sink into the cavity through the opening and then curing it.

[0036] A second heat dissipation plate, fixed to the outer casing, is provided at the opening;

[0037] Thermally conductive material is injected into the cavity between the first heat sink and the second heat sink through the opening. The thermally conductive material is located on the side of the insulating layer away from the first heat sink.

[0038] The thermally conductive material is cured to obtain a thermally conductive layer, so that the thermally conductive layer is bonded to the second heat sink.

[0039] The beneficial effects of this application include:

[0040] This application provides a power module and its packaging method, including a cavity formed by a shell and a first heat sink. A chip can be disposed within the cavity, and the chip can lead current out of the power module through electrode leads. A thin insulating layer is disposed within the cavity, and the insulating layer is bonded to the exposed surface of the cavity and the surface of the electrode leads in a coating manner. After thermally conductive material is poured into the cavity through an opening, the thermally conductive layer formed by the cured thermally conductive material can effectively cover the chip and electrode leads with height differences. Thus, a new heat dissipation path can be established through the thermally conductive layer above the first heat sink, so that in addition to the first heat sink at the bottom of the chip, heat dissipation can also be achieved from the periphery and top through the thermally conductive layer covering the outside of the chip, thereby forming double-sided heat dissipation of the power module and improving the heat dissipation performance of the power module. Attached Figure Description

[0041] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1One of the flowcharts of a power module packaging method provided in this application embodiment;

[0043] Figure 2 A second schematic flowchart illustrating a power module packaging method provided in this application embodiment;

[0044] Figure 3 This is one of the structural schematic diagrams of a power module provided in an embodiment of this application;

[0045] Figure 4 This is a second schematic diagram of the structure of a power module provided in an embodiment of this application;

[0046] Figure 5 This is the third schematic diagram of a power module provided in an embodiment of this application.

[0047] Icons: 110-Chip; 120-Connection layer; 130-Substrate; 140-First heat sink; 150-Casing; 160-Metal wire; 170-Insulating layer; 171-First sub-insulating layer; 172-Second sub-insulating layer; 180-Heat-conducting layer; 190-Second heat sink; 210-Metal sheet. Detailed Implementation

[0048] The embodiments described below represent the information necessary for those skilled in the art to practice the embodiments and illustrate the best mode for practicing the embodiments. After reading the following description with reference to the accompanying drawings, those skilled in the art will understand the concepts of this disclosure and will recognize the application of these concepts not specifically set forth herein. It should be understood that these concepts and applications fall within the scope of this disclosure and the appended claims.

[0049] It should be understood that while the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0050] It should be understood that when an element (such as a layer, region, or substrate) is referred to as "on another element" or "extending to another element," it may be directly on or directly extended to the other element, or there may be an intermediate element. Conversely, when an element is referred to as "directly on another element" or "directly extending to another element," there is no intermediate element. Similarly, it should be understood that when an element (such as a layer, region, or substrate) is referred to as "above another element" or "extending above another element," it may be directly on or directly extended to the other element, or there may be an intermediate element. Conversely, when an element is referred to as "directly on another element" or "extending directly to another element," there is no intermediate element. It should also be understood that when an element is referred to as "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be an intermediate element. Conversely, when an element is referred to as "directly connected" or "directly coupled" to another element, there is no intermediate element.

[0051] Related terms such as “below”, “above”, “upper”, “lower”, “horizontal”, or “vertical” are used herein to describe the relationship of one element, layer, or region to another, as illustrated in the figures. It should be understood that these terms, and those discussed above, are intended to cover different orientations of the device other than those depicted in the figures.

[0052] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, the singular forms “a,” “an,” and “described” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that, when used herein, the term “comprising” indicates the presence of the stated feature, integer, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups of the foregoing.

[0053] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that the terms used herein should be interpreted as having the same meaning as they would in the context of this specification and the relevant field, and not in an idealized or overly formal sense, unless explicitly defined herein.

[0054] One aspect of this application provides a power module, such as... Figure 3As shown, it includes a first heat sink 140 and a housing 150. The housing 150 is disposed around the periphery of the first heat sink 140. Thus, the housing 150 can cooperate with the bottom first heat sink 140 to form an open cavity. A chip 110 located on the first heat sink 140 can be disposed in the cavity. Thus, a bottom heat dissipation path can be formed below the chip 110.

[0055] Please continue to refer to Figure 3 As shown, chip 110 can lead current out of the power module via electrode leads. The highest point of the electrode leads may have a height difference with chip 110. To facilitate the formation of a heat dissipation path above the first heat sink 140, thus forming a double-sided heat dissipation structure, a thin insulating layer 170 can be first set in the cavity, so that the insulating layer 170 is bonded to the exposed surface of the cavity and the surface of the electrode leads in a coating manner. Specifically, as shown... Figure 2 As shown, the insulating layer 170 can be coated on the surfaces of the housing 150, the first heat sink 140, the chip 110, and the electrode leads exposed in the inner cavity. It should be understood that, in this application, "coated" refers to a thin insulating layer 170. Figure 2 The insulating layer 170 is bonded to the exposed surfaces and electrode leads within the cavity in the manner shown. Partially, the insulating layer 170 bonded to the electrode leads is suspended, while the non-insulating layer 170 is entirely filled with a thicker portion of the cavity. Therefore, the upper surface of the insulating layer 170 remains uneven. This design effectively insulates the exposed surfaces and electrode leads throughout the cavity while avoiding the problem of excessively thick insulating layers.

[0056] like Figure 3As shown, thermally conductive material can be injected into the cavity through the opening. Since the cavity already has an insulating layer 170 covering the exposed surface, the injected thermally conductive material can fully fill the remaining space in the cavity while also providing insulation and isolation between the insulating layer 170 and the chip 110, electrode leads, etc. After curing, the thermally conductive material forms a thermally conductive layer 180, which is located on the side of the insulating layer 170 facing away from the first heat sink 140. Due to the injection and filling of the thermally conductive material, the cured thermally conductive layer 180 can support the suspended part of the electrode leads covered with the insulating layer 170. At the same time, the injection and curing process allows the thermally conductive layer 180 to better cover the chip 110 and electrode leads with height differences. Therefore, a new heat dissipation path can be established through the thermal conductive layer 180 above the first heat sink 140, so that in addition to the first heat sink 140 at the bottom of the chip 110, the heat dissipation path can also dissipate heat from the periphery and top through the thermal conductive layer 180 covering the outside of the chip 110, thereby forming double-sided heat dissipation of the power module and improving the heat dissipation performance of the power module.

[0057] Optional, such as Figure 2 As shown, the insulating layer 170 includes a first sub-insulating layer 171 and a second sub-insulating layer 172. The first sub-insulating layer 171 covers the exposed surfaces inside and outside the cavity, and the second sub-insulating layer 172 covers the surface of the electrode lead. The second sub-insulating layer 172 can be connected to the first sub-insulating layer 171 along with the end of the electrode lead. However, the middle part of the second sub-insulating layer 172 outside both ends is suspended relative to the first sub-insulating layer 171. That is, the thickness of the first sub-insulating layer 171 is less than the height difference between the highest point of the electrode lead and the chip 110, making the insulating layer 170 thinner. Therefore, the upper surface of the insulating layer 170 is still uneven and not flat.

[0058] Of course, such as Figure 2 As shown, the thickness of the first sub-insulating layer 171 and the thickness of the second sub-insulating layer 172 can be approximately equal, thus keeping the overall thickness of the insulating layer 170 relatively thin. Therefore, the upper surface of the insulating layer 170 is still uneven and not flat.

[0059] Optionally, to further enhance the heat dissipation capability of the power module, such as... Figure 4 As shown, a second heat sink 190 can be provided on the surface of the heat-conducting layer 180 opposite to the first heat sink 140 (i.e., the top surface of the heat-conducting layer 180). Furthermore, the top surface of the heat-conducting layer 180 can be made flat, and the second heat sink 190 is disposed in close contact with the flat surface. This allows the heat-conducting layer 180 to have full contact with the second heat sink 190 at all points, which helps to improve the heat dissipation performance of the power module.

[0060] In some embodiments, the thermally conductive layer 180 may be a non-colloidal thermally conductive layer 180, thereby avoiding the dramatic increase in thermal resistance caused by the injection of colloid.

[0061] In some embodiments, the thermally conductive layer 180 can be a curable sinterable metal paste or metal powder, such as sintered copper or other sintered metals. This allows the thermally conductive layer 180 to have good heat dissipation capabilities.

[0062] In some embodiments, the resistivity of the thermally conductive layer 180 is less than 10. -6 Ωm;

[0063] In some implementations, the thermal conductivity of the thermally conductive layer 180 is greater than 3 W / mK;

[0064] In some embodiments, the insulating layer 170 is a curable material, which may be a mixture of ceramic and resin, such as a mixture of ceramic powder and resin material.

[0065] In some embodiments, the resistivity of the insulating layer 170 is greater than 10. 6 Ωm.

[0066] Optional, such as Figures 1 to 4 As shown, the electrode lead-out component is a metal wire 160. Wire bonding can be used to create wires on the electrodes of the chip 110, allowing the chip 110 to draw current outwards via the metal wire 160. Therefore, in conjunction with the aforementioned heat dissipation structure, double-sided heat dissipation can be achieved with lower manufacturing difficulty and cost.

[0067] Optional, such as Figure 5 As shown, the electrode lead-out component can also be a metal sheet 210. The metal sheet 210 can adopt a pre-formed shape to facilitate the outward lead-out of the current of the chip 110. One end of the metal sheet 210 is soldered to the electrode pad of the chip 110. It has good pressure bearing capacity. At the same time, the metal sheet 210 can also have a wide cross-sectional area, thereby further reducing parasitic resistance.

[0068] Optional, such as Figures 1 to 5 As shown, a substrate 130 is also disposed between the chip 110 and the first heat sink 140. The chip 110 can be connected to the substrate 130 via electrode leads, thereby realizing the extraction of current from the chip 110. Of course, in other embodiments, such as Figures 1 to 5 As shown (or in embodiments without substrate 130), chip 110 can also be directly connected to housing 150 via electrode leads, thereby enabling the extraction of current from chip 110. In embodiments with substrate 130, insulating layer 170 also covers the surface of substrate 130 exposed in the cavity.

[0069] Specifically, such as Figures 1 to 5 As shown, chip 110 and first heat sink 140 are respectively attached to opposite sides of substrate 130. A connecting layer 120 can be used to connect chip 110 and substrate 130, as well as the first heat sink 140 and substrate 130, thereby improving the stability of the connection. The connecting layer 120 can be a metal layer.

[0070] In some embodiments, the substrate 130 may be a ceramic substrate 130, thereby improving heat dissipation.

[0071] Optionally, the chip 110 located within the cavity can be at least one, for example... Figures 1 to 5 As shown, there are two chips 110. The two chips 110 can be disposed on the same substrate 130 or on different substrates 130. This application does not impose any restrictions on this.

[0072] Another aspect of this application provides a power module packaging method, the method comprising:

[0073] S010: Provides chip 110;

[0074] S020: Chip 110 is disposed on the first heat sink 140;

[0075] S030: A housing 150 is provided around the periphery of the first heat sink 140 so that the housing 150 cooperates with the first heat sink 140 to form a cavity with an opening, and the chip 110 is located in the cavity.

[0076] S040: Electrode leads are provided on the surface of chip 110;

[0077] Please refer to Figure 1 As shown, the chip 110 can be first placed on the first heat sink 140, and then a housing 150 can be joined to the periphery of the first heat sink 140. Thus, the housing 150 and the first heat sink 140 enclose a cavity with an opening, and the chip 110 is located inside the cavity. Then, electrode leads are provided on the surface of the chip 110 to lead the current outward through the electrode leads.

[0078] like Figure 1 As shown, in an embodiment with substrate 130, chip 110 can be bonded to substrate 130 first, and then substrate 130 with chip 110 can be bonded to first heat sink 140.

[0079] S050: Insulating material is added into the cavity through the opening;

[0080] S060: Remove the insulating material covering the exposed surfaces inside the cavity and the surface of the electrode leads, and cure to obtain the insulating layer 170;

[0081] like Figure 2 As shown, insulating material can be directly poured or sprayed into the cavity through the opening. After the insulating material is completely bonded to the exposed surface of the cavity and the surface of the electrode lead, the excess insulating material can be poured out to remove the excess insulating material. This allows the remaining insulating material in the cavity to cover the exposed surface of the cavity and the surface of the electrode lead with a relatively thin layer. Then, it can be cured to obtain the aforementioned insulating layer 170.

[0082] S070: Thermally conductive material located on the side of the insulating layer 170 away from the first heat sink 140 is injected into the cavity through the opening and cured to obtain the thermally conductive layer 180.

[0083] like Figure 3 As shown, thermally conductive material can be injected into the cavity through the opening. Since the cavity already has an insulating layer 170 covering the exposed surface, the injected thermally conductive material can fully fill the remaining space in the cavity while also providing insulation and isolation between the insulating layer 170 and the chip 110, electrode leads, etc. After curing, the thermally conductive material forms a thermally conductive layer 180, which is located on the side of the insulating layer 170 facing away from the first heat sink 140. Due to the injection and filling of the thermally conductive material, the cured thermally conductive layer 180 can support the suspended part of the electrode leads covered with the insulating layer 170. At the same time, the injection and curing process allows the thermally conductive layer 180 to better cover the chip 110 and electrode leads with height differences. Therefore, a new heat dissipation path can be established through the thermal conductive layer 180 above the first heat sink 140, so that in addition to the first heat sink 140 at the bottom of the chip 110, heat dissipation can also be achieved through the thermal conductive layer 180 covering the outside of the chip 110, thereby forming double-sided heat dissipation of the power module and improving the heat dissipation performance of the power module.

[0084] Optional, such as Figure 2 As shown, the insulating layer 170 includes a first sub-insulating layer 171 and a second sub-insulating layer 172. The first sub-insulating layer 171 covers the exposed surfaces inside and outside the cavity, and the second sub-insulating layer 172 covers the surface of the electrode lead. The second sub-insulating layer 172 can be connected to the first sub-insulating layer 171 along with the end of the electrode lead. However, the middle part of the second sub-insulating layer 172 outside both ends is suspended relative to the first sub-insulating layer 171. That is, the thickness of the first sub-insulating layer 171 is less than the height difference between the highest point of the electrode lead and the chip 110, making the insulating layer 170 thinner. Therefore, the upper surface of the insulating layer 170 is still uneven and not flat.

[0085] Of course, such as Figure 2As shown, the thickness of the first sub-insulating layer 171 and the thickness of the second sub-insulating layer 172 can be approximately equal, thus keeping the overall thickness of the insulating layer 170 relatively thin. Therefore, the upper surface of the insulating layer 170 is still uneven and not flat.

[0086] Optionally, to further enhance the heat dissipation capability of the power module, such as... Figure 4 As shown, a second heat sink 190 can be provided on the surface of the heat-conducting layer 180 opposite to the first heat sink 140 (i.e., the top surface of the heat-conducting layer 180). Furthermore, the top surface of the heat-conducting layer 180 can be made flat, and the second heat sink 190 is disposed in close contact with the flat surface. This allows the heat-conducting layer 180 to have full contact with the second heat sink 190 at all points, which helps to improve the heat dissipation performance of the power module.

[0087] Optionally, when the heat-conducting layer 180 is set in S070, it can be combined with the embodiment having the second heat sink 190. The steps can specifically include: first, injecting heat-conducting material into the cavity through the opening, with the heat-conducting material located on the side of the insulating layer 170 away from the first heat sink 140; then, setting the second heat sink 190 on the side of the heat-conducting material away from the first heat sink 140; by curing the heat-conducting material, the heat-conducting layer 180 can be obtained, and the curing of the heat-conducting material can also make the heat-conducting layer 180 bond with the second heat sink 190, which helps to improve the stability of the bond between the second heat sink 190 and the heat-conducting layer 180.

[0088] Optionally, when the heat-conducting layer 180 is set in S070, it can be combined with the embodiment having the second heat sink 190. The steps may further include: first, setting the second heat sink 190 fixed to the outer shell 150 at the opening; then, injecting heat-conducting material into the cavity below the second heat sink 190 through the opening, the heat-conducting material being located on the side of the insulating layer 170 away from the first heat sink 140; by curing the heat-conducting material, the heat-conducting layer 180 can be obtained, and the curing of the heat-conducting material can also make the heat-conducting layer 180 bond with the second heat sink 190, which helps to improve the stability of the bond between the second heat sink 190 and the heat-conducting layer 180.

[0089] In some embodiments, the thermally conductive layer 180 may be a non-colloidal thermally conductive layer 180, thereby avoiding the dramatic increase in thermal resistance caused by the injection of colloid.

[0090] In some embodiments, the thermally conductive layer 180 can be a curable sinterable metal paste or metal powder, such as sintered copper or other sintered metals. This allows the thermally conductive layer 180 to have good heat dissipation capabilities.

[0091] In some embodiments, the resistivity of the thermally conductive layer 180 is less than 10. -6 Ωm;

[0092] In some implementations, the thermal conductivity of the thermally conductive layer 180 is greater than 3 W / mK;

[0093] In some embodiments, the insulating layer 170 is a curable material, which may be a mixture of ceramic and resin, such as a mixture of ceramic powder and resin material.

[0094] In some embodiments, the resistivity of the insulating layer 170 is greater than 10. 6 Ωm.

[0095] Optional, such as Figures 1 to 4 As shown, the electrode lead-out component is a metal wire 160. Wire bonding can be used to create wires on the electrodes of the chip 110, allowing the chip 110 to draw current outwards via the metal wire 160. Therefore, in conjunction with the aforementioned heat dissipation structure, double-sided heat dissipation can be achieved with lower manufacturing difficulty and cost.

[0096] Optional, such as Figure 5 As shown, the electrode lead-out component can also be a metal sheet 210. The metal sheet 210 can adopt a pre-formed shape to facilitate the outward lead-out of the current of the chip 110. One end of the metal sheet 210 is soldered to the electrode pad of the chip 110. It has good pressure bearing capacity. At the same time, the metal sheet 210 can also have a wide cross-sectional area, thereby further reducing parasitic resistance.

[0097] Optional, such as Figures 1 to 5 As shown, a substrate 130 is also disposed between the chip 110 and the first heat sink 140. The chip 110 can be connected to the substrate 130 via electrode leads, thereby realizing the extraction of current from the chip 110. Of course, in other embodiments, such as Figures 1 to 5 As shown (or in embodiments without substrate 130), chip 110 can also be directly connected to housing 150 via electrode leads, thereby enabling the extraction of current from chip 110. In embodiments with substrate 130, insulating layer 170 also covers the surface of substrate 130 exposed in the cavity.

[0098] Specifically, such as Figures 1 to 5 As shown, chip 110 and first heat sink 140 are respectively attached to opposite sides of substrate 130. A connecting layer 120 can be used to connect chip 110 and substrate 130, as well as the first heat sink 140 and substrate 130, thereby improving the stability of the connection. The connecting layer 120 can be a metal layer.

[0099] In some embodiments, the substrate 130 may be a ceramic substrate 130, thereby improving heat dissipation.

[0100] Optionally, the chip 110 located within the cavity can be at least one, for example... Figures 1 to 5 As shown, there are two chips 110. The two chips 110 can be disposed on the same substrate 130 or on different substrates 130. This application does not impose any restrictions on this.

[0101] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A power module, characterized in that, include: First heat sink; The outer casing is disposed around the periphery of the first heat sink to cooperate with the first heat sink to form an open cavity; A chip, wherein the chip is disposed on a first heat sink plate within the cavity; An electrode lead-out component is connected to a chip within the cavity; An insulating layer is provided, which covers the exposed surface within the cavity and the surface of the electrode leads. A thermally conductive layer is injected into the cavity through the opening, and the thermally conductive layer is located on the side surface of the insulating layer opposite to the first heat sink. The thermally conductive layer is a cured metal paste; The surface of the thermal conductive layer opposite to the first heat sink is flat, and a second heat sink is attached to the flat surface. When the thermal conductive layer is cured, the second heat sink is bonded to the thermal conductive layer. The insulating layer includes a first sub-insulating layer covering the exposed surfaces inside and outside the cavity and a second sub-insulating layer covering the surface of the electrode lead-out. The thickness of the first sub-insulating layer is less than the height difference between the highest point of the electrode lead-out and the chip, and the thicknesses of the first sub-insulating layer and the second sub-insulating layer are approximately equal.

2. The power module as described in claim 1, characterized in that, The resistivity of the thermally conductive layer is less than 10. -6 Ωm; Alternatively, the thermal conductivity of the thermally conductive layer is greater than 3 W / mK; Alternatively, the insulating layer may be made of a mixture of ceramic and resin; Alternatively, the resistivity of the insulating layer is greater than 10. 6 Ωm.

3. The power module as described in claim 1, characterized in that, The electrode lead-out component is a metal wire or a metal sheet.

4. The power module as described in any one of claims 1 to 3, characterized in that, A substrate is also disposed between the chip and the first heat sink, and the chip is connected to the housing or the substrate via the electrode lead-out.

5. A power module packaging method, characterized in that, The method includes: Provide chips; The chip is mounted on the first heat sink. A housing is provided around the periphery of the first heat sink so that the housing cooperates with the first heat sink to form a cavity with an opening, and the chip is located in the cavity; Electrode leads are provided on the surface of the chip; Insulating material is added into the cavity through the opening; Remove the insulating material covering the exposed surfaces inside the cavity and the surface of the electrode leads, and then cure it to obtain an insulating layer; A thermally conductive material located on the side of the insulating layer away from the first heat sink is poured into the cavity through the opening and cured to obtain a thermally conductive layer. The thermally conductive material is a metal paste. During the curing of the thermally conductive layer, the second heat sink adheres to the thermally conductive layer. The insulating layer includes a first sub-insulating layer covering the exposed surfaces inside and outside the cavity and a second sub-insulating layer covering the surface of the electrode lead-out. The thickness of the first sub-insulating layer is less than the height difference between the highest point of the electrode lead-out and the chip, and the thicknesses of the first sub-insulating layer and the second sub-insulating layer are approximately equal.

6. The power module packaging method as described in claim 5, characterized in that, The process of injecting thermally conductive material located on the side of the insulating layer opposite to the first heat sink into the cavity through the opening and then curing it to obtain the thermally conductive layer includes: Thermally conductive material is injected into the cavity through the opening, and the thermally conductive material is located on the side of the insulating layer away from the first heat sink. A second heat sink is provided on the side of the thermally conductive material that is away from the first heat sink. The thermally conductive material is cured to obtain the thermally conductive layer, so that the thermally conductive layer is bonded to the second heat sink.

7. The power module packaging method as described in claim 5, characterized in that, The process of injecting thermally conductive material located on the side of the insulating layer opposite to the first heat sink into the cavity through the opening and then curing it to obtain the thermally conductive layer includes: A second heat dissipation plate, fixed to the outer casing, is provided at the opening; Thermally conductive material is injected into the cavity between the first heat sink and the second heat sink through the opening, and the thermally conductive material is located on the side of the insulating layer away from the first heat sink. The thermally conductive material is cured to obtain the thermally conductive layer, so that the thermally conductive layer is bonded to the second heat sink.

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