A power module

Abstract

This application provides a power module comprising: a first insulating substrate and a second insulating substrate, stacked along a first direction; a plurality of first power chips, each disposed on one side of the first insulating substrate and the second insulating substrate opposite to each other; a first power terminal and a first driving terminal; the pass terminals of the first power chips on the first insulating substrate and the first power chips on the second insulating substrate are electrically connected to the first power terminal via first conductive posts; the control terminals of the first power chips on the first insulating substrate and the first power chips on the second insulating substrate are electrically connected to the first driving terminal via second conductive posts, thereby enabling the first power chips on the first insulating substrate and the first power chips on the second insulating substrate to be connected in parallel. This application can improve the problem of thermal failure in power modules with multiple parallel power chips.

Description

Technical Field

[0001] This application relates to electronic technology, and in particular to a power module. Background Technology

[0002] To meet the rigid requirements of modern power electronic systems for high power density, high dynamic response, and high reliability, power modules are developing towards increasingly higher current carrying capacity, which also corresponds to the current transition in application fields such as new energy.

[0003] To overcome the current carrying capacity limit of a single power chip, power modules typically employ a multi-chip parallel packaging approach. This not only multiplies the current capacity but also effectively reduces on-resistance, thereby lowering the power module's conduction losses. However, existing multi-chip parallel packaged power modules suffer from issues such as susceptibility to thermal failure. Summary of the Invention

[0004] In view of the above problems, the main technical problem to be solved by this application is how to improve the thermal failure of power modules in multi-parallel power chips.

[0005] To solve the above-mentioned technical problems, the technical solution adopted in this application is conceived as follows: a power module is provided, the power module comprising: a first insulating substrate and a second insulating substrate, stacked along a first direction; a plurality of first power chips, each of which is disposed on one side of the first insulating substrate and the second insulating substrate opposite to each other; a first power terminal and a first driving terminal, wherein the pass terminals of the first power chips on the first insulating substrate and the pass terminals of the first power chips on the second insulating substrate are electrically connected to the first power terminal through a first conductive post, and the control terminals of the first power chips on the first insulating substrate and the control terminals of the first power chips on the second insulating substrate are electrically connected to the first driving terminal through a second conductive post, so that the first power chips on the first insulating substrate and the first power chips on the second insulating substrate are arranged in parallel.

[0006] In some embodiments, the access terminal includes a first access terminal and a second access terminal; the first conductive post includes a first sub-conductive post and a second sub-conductive post; the first power terminal includes a first polarity power terminal and a second polarity power terminal; the first access terminal of the first power chip on the first insulating substrate and the first access terminal of the first power chip on the second insulating substrate are electrically connected to the first polarity power terminal through the first sub-conductive post; the second access terminal of the first power chip on the first insulating substrate is electrically connected to the upper metal layer of the first insulating substrate, the second access terminal of the first power chip on the second insulating substrate is electrically connected to the upper metal layer of the second insulating substrate, and the upper metal layer of the first insulating substrate and the upper metal layer of the second insulating substrate are electrically connected to the second polarity power terminal through the second sub-conductive post.

[0007] In some embodiments, the second sub-conductive post is disposed between the first insulating substrate and the second insulating substrate along the first direction, and is located outside the first power chip along the second direction; the first sub-conductive post is located between the first power chip disposed on the first insulating substrate along the first direction and the first power chip on the second insulating substrate; wherein, the second direction is perpendicular to the first direction.

[0008] In some embodiments, the first polar power terminal, the second polar power terminal, and the first drive terminal extend in a plane perpendicular to the first direction, with the first polar power terminal and the second polar power terminal extending in opposite directions and the first polar power terminal and the first drive terminal extending in the same direction.

[0009] In some embodiments, the power module further includes: a plurality of second power chips, wherein the second power chips are disposed on one side of the first insulating substrate and the second insulating substrate respectively; a second power terminal and a second driving terminal, wherein the pass terminals of the second power chips on the first insulating substrate and the pass terminals of the second power chips on the second insulating substrate are electrically connected to the second power terminal through a third conductive post, and the control terminals of the second power chips on the first insulating substrate and the control terminals of the second power chips on the second insulating substrate are electrically connected to the second driving terminal through a fourth conductive post, so that the second power chips on the first insulating substrate and the second power chips on the second insulating substrate are arranged in parallel; wherein the first power chip and the second power chip are spaced apart along a third direction, and the third direction is perpendicular to the first direction.

[0010] In some embodiments, a plurality of first power chips are provided on both the first insulating substrate and the second insulating substrate, arranged along a second direction; the second direction is perpendicular to the first direction and the third direction, respectively.

[0011] In some embodiments, the first power terminal includes a first polarity power terminal and a second polarity power terminal, which are electrically connected to a first channel terminal and a second channel terminal of the first power chip, respectively; the second power terminal includes a third polarity power terminal and a fourth polarity power terminal, which are electrically connected to a first channel terminal and a second channel terminal of the second power chip, respectively; wherein, the first driving terminal and the second driving terminal are disposed on the same side; the first polarity power terminal and the third polarity power terminal are disposed on the same side; the fourth polarity power terminal is disposed on the same side as the second polarity power terminal, and may be disposed on the same side or opposite side to the third polarity power terminal.

[0012] In some embodiments, the fourth polarity power terminal and the second polarity power terminal are the same terminal or are electrically connected.

[0013] In some embodiments, the second polarity power terminal and the third polarity power terminal are the same terminal or electrically connected to form an AC terminal.

[0014] In some embodiments, the power module further includes: a housing, at least disposed on the side of the first insulating substrate opposite to the second insulating substrate and / or the side of the second insulating substrate opposite to the first insulating substrate; wherein the material of the housing includes metal and / or phase change material.

[0015] In some embodiments, the outer casing uses the metal as a frame and is filled with the phase change material.

[0016] In some embodiments, the thickness of the outer casing is greater than or equal to 13 mm.

[0017] In some embodiments, the housing is provided with a mounting through hole, and the power module further includes a fifth conductive post and an insulating ring. The fifth conductive post is partially disposed within the mounting through hole, and the insulating ring is at least disposed between the inner wall of the mounting through hole and the conductive post.

[0018] In some embodiments, the power module further includes a heat dissipation component, which is at least disposed on the side of the first insulating substrate opposite to the second insulating substrate and / or on the side of the second insulating substrate opposite to the first insulating substrate.

[0019] In some embodiments, the heat dissipation component includes a cold plate, an air-cooled radiator, or a water-cooled radiator.

[0020] The advantages of the embodiments of this application, which differ from the prior art, are as follows: The power module of this application includes: a first insulating substrate, a second insulating substrate, a plurality of first power chips, a first power terminal, and a first driving terminal; wherein, the first insulating substrate and the second insulating substrate are stacked along a first direction; a first power chip is provided on one side of the first insulating substrate and the second insulating substrate that are opposite to each other; the pass-through terminals of the first power chips on the first insulating substrate and the pass-through terminals of the first power chips on the second insulating substrate are electrically connected to the first power terminal through a first conductive post, and the control terminals of the first power chips on the first insulating substrate and the control terminals of the first power chips on the second insulating substrate are electrically connected to the first driving terminal through a second conductive post, so that the first power chips on the first insulating substrate and the first power chips on the second insulating substrate are arranged in parallel. On the one hand, the first power chip on the first insulating substrate and the first power chip on the second insulating substrate are arranged in parallel, which can improve the current carrying capacity of the power chip and reduce the conduction loss of the power module. On the other hand, the first power chip on the first insulating substrate and the first power chip on the second insulating substrate are arranged along the stacking direction of the first insulating substrate and the second insulating substrate, and are arranged on the side opposite to the first insulating substrate and the second insulating substrate. This can realize the face-to-face stacking of the first power chip, thereby making full use of the space of the power module in the stacking direction, realizing the full utilization of three-dimensional space, and facilitating heat dissipation on both sides of the first power chip in the stacking direction, which can improve the heat dissipation effect of the power module itself and improve the problem of thermal failure. Furthermore, the control terminal and the path terminal of the first power chip are connected to the corresponding terminal through the corresponding conductive post, which can improve the problem of low reliability caused by easy breakage of solder joints when using bonding wire connection. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a schematic diagram of the structure of the power module of the first embodiment of this application; Figure 2 yes Figure 1 A side view of the power module in the embodiment; Figure 3 yes Figure 1 A cross-sectional structural diagram of the power module in the embodiment; Figure 4 This is a structural schematic diagram of the fourth embodiment of the power module of this application; Figure 5This is a structural schematic diagram of the fifth embodiment of the power module of this application; Figure 6 This is a schematic diagram of the structure of the power module of the sixth embodiment of this application; Figure 7 This is a structural schematic diagram of the seventh embodiment of the power module of this application; Figure 8 It is a graph showing the temperature rise and fall of the power chip in a traditional power module structure; Figure 9 This is a schematic diagram of the temperature rise and fall curves of the power chip in the power module of this application; Figure 10 This is a schematic cross-sectional view of the temperature distribution of the power module 10 seconds after power is applied. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are only for explaining this application and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, not all structures. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0023] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0027] To meet the rigid requirements of modern power electronic systems for high power density, high dynamic response, and high reliability, power modules are developing towards increasingly higher current carrying capacity, which also corresponds to the current transition in application fields such as new energy.

[0028] To overcome the current carrying capacity limit of a single power chip, power modules typically employ a multi-chip parallel packaging approach. This not only doubles the current carrying capacity but also effectively reduces on-resistance, thereby lowering the power module's conduction losses.

[0029] In related technologies, power chips are typically placed horizontally on the same insulating substrate, and the power chips are electrically connected to each other via bonding wires. This structure causes several problems when the number of power chips connected in parallel becomes too large: the number of power chips that can be placed within a fixed package size is limited, resulting in limited current carrying capacity; when the power chips are placed too closely and densely, the thermal coupling between the power chips becomes severe, causing the junction temperature of the power chips to rise and easily leading to thermal failure; the solder joints of the bonding wires are weak points in reliability, and as the number of power chips connected in parallel increases, the number of bonding wires required also increases, making solder joint breakage more likely and resulting in lower reliability.

[0030] To address this, this application proposes a power module. Firstly, a first power chip on a first insulating substrate and a first power chip on a second insulating substrate are connected in parallel, which improves the current-carrying capacity of the power chips and reduces the conduction loss of the power module. Secondly, the first power chips on the first and second insulating substrates are arranged along the stacking direction of the first and second insulating substrates, and are positioned on opposite sides of the first and second insulating substrates. This allows for face-to-face stacking of the first power chips, fully utilizing the space in the stacking direction of the power module and achieving full utilization of three-dimensional space. It also facilitates heat dissipation from both sides of the first power chip in the stacking direction, improving the heat dissipation effect of the power module itself and mitigating thermal failure. Thirdly, the control terminal and the access terminal of the first power chip are connected to corresponding terminals via corresponding conductive posts, which improves the reliability issue caused by the easy breakage of solder joints when using bonding wire connections.

[0031] In some embodiments, such as Figures 1 to 7 As shown, the power module 100 includes: a first insulating substrate 10, a second insulating substrate 11, a plurality of (two or more) first power chips 20, a first power terminal 30, and a first drive terminal 40; wherein, the first insulating substrate 10 and the second insulating substrate 11 are stacked along a first direction z; the first insulating substrate 10 and the second insulating substrate 11 are each provided with a first power chip 20 on one side opposite to each other; the pass terminal 21 of the first power chip 20 on the first insulating substrate 10 and the pass terminal 21 of the first power chip 20 on the second insulating substrate 11 are electrically connected to the first power terminal 30 through a first conductive post 50, and the control terminal 22 of the first power chip 20 on the first insulating substrate 10 and the control terminal 22 of the first power chip 20 on the second insulating substrate 11 are electrically connected to the first drive terminal 40 through a second conductive post 63, so that the first power chip 20 on the first insulating substrate 10 and the first power chip 20 on the second insulating substrate 11 are arranged in parallel.

[0032] The pass-through terminals 21 of the first power chips 20 on the first insulating substrate 10 and the second insulating substrate 11 are both electrically connected to the first power terminal 30, and the control terminals 22 of the first power chips 20 on the first insulating substrate 10 and the second insulating substrate 11 are both electrically connected to the first drive terminal 40, so that the first power chips 20 on the first insulating substrate 10 and the second insulating substrate 11 are arranged in parallel to improve the current carrying capacity of the power module 100.

[0033] On the one hand, the first power chip 20 on the first insulating substrate 10 and the first power chip 20 on the second insulating substrate 11 are arranged in parallel, which can improve the current carrying capacity of the power module 100 and reduce the conduction loss of the power module 100. On the other hand, the first power chip 20 on the first insulating substrate 10 and the first power chip 20 on the second insulating substrate 11 are arranged along the stacking direction of the first insulating substrate 10 and the second insulating substrate 11, that is, the first direction z, and are arranged on the side opposite to the first insulating substrate 10 and the second insulating substrate 11, which can realize the face-to-face stacking arrangement of the first power chip 20. This can make full use of the space of the power module 100 in the stacking direction, realize the full utilization of the three-dimensional space, and facilitate the heat dissipation of the two sides (large surface) of the first power chip 20 in the stacking direction, thereby improving the heat dissipation effect of the power module 100 itself and improving the problem of thermal failure. Furthermore, the control terminal 22 and the access terminal 21 of the first power chip 20 are connected to the corresponding terminals through corresponding conductive posts, which can improve the problem of low reliability caused by easy breakage of solder joints when using bonding wire connections.

[0034] Furthermore, in this embodiment, the power module 100 is symmetrically arranged along the first direction z, which makes the stress symmetrically distributed and can effectively improve the reliability of the power module.

[0035] The first power chip 20 is the core component of the power module 100. In some embodiments, the first power chip 20 may include an IGBT chip, a MOSFET (Si / SiC / GaN) chip, a fast recovery diode (FRD), etc., and is mainly used to perform core power conversion such as switching, rectification, and inversion of electrical energy. The power module 100 may include multiple first power chips 20 to realize circuit structures such as half-bridge, full-bridge, and three-phase bridge.

[0036] The power module 100 can be composed of multiple MOSFET chips connected in parallel, multiple IGBT chips connected in parallel, or IGBT chips and MOSFET chips connected in parallel, etc., and is suitable for various device types.

[0037] In some embodiments, the aforementioned direct-bonded copper (DBC) substrate, serving as the core carrier of the power module 100, may include a three-layer composite structure: an upper metal layer (not shown), an insulating layer (not shown), and another upper metal layer (not shown). The upper metal layer is used to etch circuit traces, creating a conductive pattern layer to enable interconnection between the first power chips 20 or connection between the first power chips 20 and terminals. The insulating layer provides high-voltage electrical insulation and conducts heat. The upper metal layer enhances the mechanical strength of the substrate and optimizes the heat dissipation path.

[0038] In some embodiments, such as Figures 1 to 7 As shown, the first power chip 20 can also be connected to the corresponding insulating substrate through the solder layer 61 to achieve a fixed / electrical / thermal connection between the first power chip 20 and the corresponding insulating substrate.

[0039] It should be noted that the solder layer connected to the power chip of this application is collectively referred to as solder layer 61.

[0040] In some embodiments, such as Figures 1 to 7 As shown, the access terminal 21 includes a first access terminal 211 and a second access terminal 212; the first conductive post 50 includes a first sub-conductive post 51 and a second sub-conductive post 52; the first power terminal 30 includes a first polarized power terminal 31 and a second polarized power terminal 32; the first access terminal 211 of the first power chip 20 on the first insulating substrate 10 and the first access terminal 211 of the first power chip 20 on the second insulating substrate 11 are electrically connected to the first polarized power terminal 31 through the first sub-conductive post 51; the second access terminal 212 of the first power chip 20 on the first insulating substrate 10 is electrically connected to the upper metal layer (not shown) of the first insulating substrate 10; the second access terminal 212 of the first power chip 20 on the second insulating substrate 11 is electrically connected to the upper metal layer (not shown) of the second insulating substrate 11; the upper metal layer of the first insulating substrate 10 and the upper metal layer of the second insulating substrate 11 are electrically connected to the second polarized power terminal 32 through the second sub-conductive post 52.

[0041] The first power chip 20 can also be connected to the upper metal layer of the corresponding insulating substrate through the solder layer 61 to improve structural stability and electrical performance; the second channel terminal 212 is electrically connected to the second sub-conductive post 52 through the solder layer 61 and the upper metal layer.

[0042] The first channel end 211 is also electrically connected to the first sub-conductive post 51 through the solder layer 61.

[0043] For example, the first power chip 20 is a MOSFET chip. Taking two MOSFET chips as an example, the sources (S-terminals), i.e., the first path terminals 211, of the two first power chips 20 are connected to the same metal power terminal (e.g., DC-), i.e., the first polarity power terminal 31, via solder. The gates (G-terminals), i.e., the control terminals 22, of the two first power chips 20 are connected to the same metal drive terminal, i.e., the first drive terminal 40, via solder. The drains (D-terminals), i.e., the second path terminals 212, of the two first power chips 20 are respectively connected to symmetrical insulating substrates via solder. These two insulating substrates are electrically connected by metal connecting posts, i.e., the second sub-conductive posts 52, which are in turn connected to the second polarity power terminal 32 (e.g., DC+). It is worth noting that multiple first drive terminals 40 are arranged on the same side, and multiple first polarity power terminals 31 are arranged on the same side. However, the first polarity power terminals 31 and the second polarity power terminals 32 may or may not be on the same side.

[0044] The power module 100 can be multiple MOSFET chips connected in parallel, multiple IGBT chips connected in parallel, or IGBT and MOSFET chips connected in parallel, etc., and is suitable for various device types.

[0045] In some embodiments, such as Figures 1 to 7 As shown, the second sub-conductive post 52 is disposed between the first insulating substrate 10 and the second insulating substrate 11 along the first direction z, and is located outside the first power chip 20 along the second direction x; the first sub-conductive post 51 is located between the first power chip 20 disposed on the first insulating substrate 10 and the first power chip 20 disposed on the second insulating substrate 11 along the first direction z; wherein, the second direction x is perpendicular to the first direction z. This structure reduces interference between the conductive posts and makes full use of space in all directions.

[0046] In some embodiments, such as Figure 2 and Figure 3 As shown, the first polarity power terminal 31, the second polarity power terminal 32, and the first drive terminal 40 extend in the vertical plane of the first direction z. The extension directions of the first polarity power terminal 31 and the second polarity power terminal 32 are opposite to each other, while the extension directions of the first polarity power terminal 31 and the first drive terminal 40 are the same (i.e., on the same side). This structure can reduce interference between the terminals.

[0047] In some embodiments, the first polarity power terminal 31 and the second polarity power terminal 32 may be disposed on the same side, and / or the first polarity power terminal 31 and the first drive terminal 40 may be disposed on opposite sides. The first polarity power terminal 31 and the second polarity power terminal 32 may also be disposed adjacent to each other on opposite sides.

[0048] In some embodiments, such as Figure 1 and Figure 3 As shown, the power module 100 further includes: multiple (two or more) second power chips 80, second power terminals 90, and second drive terminals 41. Second power chips 80 are provided on opposite sides of the first insulating substrate 10 and the second insulating substrate 11. The access terminals 81 of the second power chips 80 on the first insulating substrate 10 and the second power chips 80 on the second insulating substrate 11 are electrically connected to the second power terminals 90 via third conductive posts 64. The control terminals 82 of the second power chips 80 on the first insulating substrate 10 and the second power chips 80 on the second insulating substrate 11 are electrically connected to the second drive terminals 41 via fourth conductive posts 62, so that the second power chips 80 on the first insulating substrate 10 and the second power chips 80 on the second insulating substrate 11 are arranged in parallel. The second power chips 80 and the first power chips 20 are spaced apart along a third direction y, which is perpendicular to the first direction z.

[0049] This structure allows for the placement of more power chips between the first insulating substrate 10 and the second insulating substrate 11, thereby increasing integration.

[0050] In some embodiments, the second power chip 80 may be connected in parallel with the first power chip 20 to further improve the current carrying capacity; or the second power chip 80 may be connected in series with the first power chip 20 to form a bridge arm circuit structure. Alternatively, multiple second power chips 80 may be mixed with multiple first power chips 20.

[0051] In some embodiments, such as Figure 2 and Figure 3 As shown, multiple first power chips 20 are arranged along a second direction x on both the first insulating substrate 10 and the second insulating substrate 11; the second direction x is perpendicular to the first direction z and the third direction y, respectively. This structure allows for the placement of more power chips between the first insulating substrate 10 and the second insulating substrate 11, fully utilizing three-dimensional space and further improving integration.

[0052] In some embodiments, such as Figure 3 As shown, multiple first power chips 20 arranged in the second direction x can be connected in parallel to improve current carrying capacity.

[0053] In some embodiments, the plurality of first power chips 20 arranged in the second direction x can also be connected in series or in a mixed configuration.

[0054] The power module 100 of this application eliminates the bonding wire process, and the power chips are symmetrically arranged in the first direction z, the second direction x and the third direction y, resulting in symmetrical stress distribution, which is more conducive to improving the reliability of the power module 100.

[0055] In some embodiments, the second power chip 80 may be a power chip of the same type or a different type.

[0056] In some embodiments, such as Figures 1 to 3 As shown, the first power terminal 30 includes a first polarity power terminal 31 and a second polarity power terminal 32, which are electrically connected to the first channel terminal 211 and the second channel terminal 212 of the first power chip 20, respectively; the second power terminal 90 includes a third polarity power terminal 91 and a fourth polarity power terminal 92, the third polarity power terminal 91 being electrically connected to the first channel terminal 811 of the second power chip 80, and the fourth polarity power terminal 92 being electrically connected to the second channel terminal 812 of the second power chip 80; wherein, the first drive terminal 40 and the second drive terminal 41 are disposed on the same side; the first polarity power terminal 31 and the third polarity power terminal 91 are disposed on the same side; the fourth polarity power terminal 92 and the second polarity power terminal 32 are disposed on the same side or opposite side to the third polarity power terminal 91.

[0057] The connection method between the second power chip 80 and each terminal can be referred to the first power chip 20.

[0058] The polarity of the first polarity power terminal 31 is the same as that of the third polarity power terminal 91, and the polarity of the second polarity power terminal 32 is the same as that of the fourth polarity power terminal 92.

[0059] In some embodiments, such as Figures 1 to 3 As shown, the fourth polarity power terminal 92 and the second polarity power terminal 32 are the same terminal or electrically connected. This structure allows the second power chip 80 to be connected in parallel with the first power chip 20.

[0060] In some embodiments, the second polarity power terminal 32 and the third polarity power terminal 91 are the same terminal or electrically connected to form an AC terminal. This structure allows the second power chip 80 and the first power chip 20 to be connected in series to form an inverter bridge structure.

[0061] The above embodiments realize the stacking of two power chips along the first direction z. In some embodiments, more power chips can be stacked, with adjacent power chips arranged face to face or back to back.

[0062] In some embodiments, such as Figures 5 to 7As shown, the power module 100 further includes a heat dissipation component 33, which is at least disposed on the side of the first insulating substrate 10 opposite to the second insulating substrate 11 and / or on the side of the second insulating substrate 11 opposite to the first insulating substrate 10. The heat dissipation component 33 can improve the heat dissipation effect of the power module 100 and further improve the problem of thermal failure.

[0063] In some embodiments, such as Figure 5 As shown, the heat dissipation assembly 33 includes a cold plate 302, an interface layer 303 and a heat dissipation substrate 301 stacked sequentially along the first direction z, with the heat dissipation substrate 301 disposed close to the corresponding insulating substrate.

[0064] This application does not limit the material of the cold plate, and it can be a metal cold plate, for example. The interface layer 303 is a key functional layer at the junction of the heat dissipation substrate 301 and the cold plate 302, which directly determines the heat conduction efficiency, electrical insulation, mechanical reliability and long-term life. The interface layer 303 may include, but is not limited to, an interconnect layer, a thermally conductive / insulating layer or a metal-ceramic transition layer.

[0065] In some embodiments, such as Figure 6 As shown, the heat dissipation component 33 includes a water-cooled radiator (not shown) to achieve water-cooled heat dissipation of the power module 100.

[0066] In some embodiments, the water-cooled radiator includes a first cold plate (not shown) and a second cold plate (not shown), with a first flow channel (not shown) formed between the first and second cold plates. The first flow channel (not shown) is used to fill a refrigerant. The water-cooled radiator has a first flow channel inside for placing the refrigerant, through which the heat from the power chip and the insulating substrate is dissipated.

[0067] This embodiment improves the sealing performance of the first flow channel by placing it inside the water-cooled radiator, thus reducing the problem of water leakage from the water-cooled radiator.

[0068] In some embodiments, such as Figure 6 As shown, the heat dissipation substrate 301 has a heat dissipation column 311 on the side opposite to the corresponding insulating substrate, and the water-cooled heat sink has a second flow channel 35. The side of the water-cooled heat sink near the heat dissipation substrate 301 has a through hole (not shown) communicating with the second flow channel 35. The second flow channel 35 is used to fill the refrigerant, and the heat dissipation column 311 extends from the through hole into the second flow channel 35. The power module 100 also includes a sealing ring (not shown), which is disposed between the inner wall of the through hole and the heat dissipation column 311.

[0069] For example, a copper substrate with pins can directly contact the fluid in a water-cooled radiator through a sealing ring, achieving direct liquid cooling and improving heat dissipation. The sealing ring also improves the water-cooled radiator's seal, mitigating leakage issues.

[0070] In some embodiments, such as Figure 7 As shown, the heat dissipation component 33 includes an air-cooled heat sink (not shown in the figure), which is connected to the corresponding insulating substrate through the interface layer 303.

[0071] The power module 100 of this application can integrate a double-sided heat dissipation system to achieve multi-path heat transfer, which is more conducive to the heat dissipation of the power chip and reduces the risk of local overheating.

[0072] In some embodiments, a thermoelectric cooling component can be provided on the side of the heat dissipation component 33 or the heat dissipation substrate 301 away from the corresponding insulating substrate to cool the heat dissipation component 33 or the heat dissipation substrate 301, thereby further reducing the junction temperature of the power chip.

[0073] With the transformation of the global energy structure and the advancement of the "dual carbon" goal, the proportion of new energy sources is gradually increasing, and the requirements for stability and security of new power systems are also rising. When the power grid is unstable, it is prone to severe operating conditions such as frequency abrupt changes, sudden load increases, and sudden load decreases. At this time, the energy storage system needs to compensate for the power gap instantaneously to maintain the stability of the grid frequency and voltage, which will cause instantaneous (second-level) high-power overload and overcurrent (two to three times or more) phenomena to the power module 100. The high energy flowing instantaneously causes the temperature of the power chip to rise rapidly. Once it exceeds the safe range, thermal failure will occur immediately, resulting in the failure and damage of the energy storage converter PCS system. Therefore, temperature control of the power module 100 is very important under short-term overcurrent conditions.

[0074] Therefore, this application increases the short-time overcurrent capability of the power module 100 by increasing its heat capacity. By slowing down the rise rate of the power chip junction temperature, a critical time window for system operation is gained. Heat capacity is defined as the amount of heat absorbed per unit temperature rise (ΔT = Q / C). From a physical perspective, the larger the heat capacity, the greater the energy absorbed to reach a unit temperature rise, and the greater the short-time overcurrent capability of the power module 100. According to the heat capacity formula C=mc, where m is mass and c is specific heat capacity, and m=ρV, where V is volume and ρ is density.

[0075] This application can increase the thermal capacity of the power module 100 by increasing at least one of the thickness, length and width of the housing 70 of the power module 100, thereby providing its short-time overcurrent capability.

[0076] In some embodiments, such as Figure 4 As shown, the power module 100 further includes: a housing 70, which is disposed at least on the side of the first insulating substrate 10 opposite to the second insulating substrate 11 and / or on the side of the second insulating substrate 11 opposite to the first insulating substrate 10; wherein the material of the housing 70 includes metal and / or phase change material.

[0077] This embodiment utilizes a material with high heat capacity to realize the housing 70, which can increase the heat capacity of the power module 100 and slow down the rise rate of the junction temperature of the power chip 20, thereby increasing the short-time overcurrent capability of the power module 100. Heat capacity is determined by mass and specific heat capacity. Therefore, under the same volume, a material with high density and high specific heat capacity can be selected to realize the housing 70, which can reduce system cost, volume and weight.

[0078] In some embodiments, the housing 70 may be a metal housing. The housing 70 serves to provide mechanical protection, electrical isolation, moisture and dust protection, and to secure terminals.

[0079] In some embodiments, the housing 70 may be made of copper; or other metals may be used instead of copper to reduce costs.

[0080] In some embodiments, the high latent heat properties of phase change materials can be further utilized by using a metal frame filled with phase change material, thereby further increasing the heat capacity of the power module 100. Alternatively, other materials can be used to realize the frame.

[0081] In some embodiments, such as Figure 4 As shown, the thickness of the housing 70 is greater than or equal to 13 mm. Within the limits allowed by the mechanical structure, further increasing the thickness, length, and width of the housing 70 can further increase the heat capacity of the power module 100 and further improve the short-time overcurrent capability of the power module 100.

[0082] In some embodiments, the thickness of the outer casing 70 is greater than or equal to 15 mm.

[0083] First, thermal simulation was performed on the traditional power module to simulate actual operating conditions. A certain power (80W) was applied to the power chip for 10 seconds, and then the application was stopped. Figure 8 As shown, Figure 8 This is a temperature rise and fall curve of the power chip in a traditional power module structure. It can be seen that the temperature of the power chip reached 118℃ at the 10th second.

[0084] In the same power module applicable to this application, the housing 70 is made of copper and has a thickness of 15mm. Power is applied in the same manner, such as... Figure 9 and Figure 10 As shown, Figure 9 This is a schematic diagram of the temperature rise and fall curves of the power chip in the power module of this application. Figure 10This is a schematic diagram of the temperature distribution of the power module after 10 seconds of power application. It shows that the temperature of the power chip is only 106℃ at 10 seconds, demonstrating the effectiveness of this technology in suppressing junction temperature. It is worth noting that the same ambient temperature and heat dissipation conditions, i.e., the structure of the water channel and the water flow rate, were maintained in both simulations. Similarly, assuming the junction temperature of the power chip is limited to below 175℃, compared to traditional power modules, this power module can handle higher power within 10 seconds, which is equivalent to having a higher short-time overcurrent capability.

[0085] Furthermore, within the limits allowed by the mechanical structure, increasing the thickness and area of ​​the outer shell 70 can further increase the heat capacity and suppress the junction temperature. Moreover, phase change materials possess high latent heat characteristics, exhibiting a very high specific heat capacity during the phase change process. Taking paraffin as an example, its specific heat capacity in its normal solid state is approximately 2000 J / (g·K), but within the temperature range where the solid-liquid phase transition occurs, its specific heat capacity can reach 20000 J / (g·K), an increase of an order of magnitude. Therefore, this characteristic can be utilized to use a metal cap / shell as a frame, embedding phase change materials to further increase the heat capacity of the power module and further improve its short-term overcurrent capability.

[0086] In some embodiments, the housing 70 is provided with a mounting through hole (not shown in the figure), and the power module 100 further includes a fifth conductive post and an insulating ring. The fifth conductive post is partially disposed in the mounting through hole, and the insulating ring is at least disposed between the inner wall of the mounting through hole and the fifth conductive post.

[0087] One end of the fifth conductive post is used for electrical connection with the conductive layer on the insulating substrate and / or the power chip, and the other end of the fifth conductive post extends through the housing 70 to the outside of the housing 70. In order to improve the heat dissipation effect, the housing 70 is usually a metal housing. In this embodiment, an insulating ring is used to achieve electrical insulation between the fifth conductive post and the housing 70.

[0088] The insulating ring 72 may be, but is not limited to, a ceramic insulating ring.

[0089] In some embodiments, such as Figures 1 to 4 As shown, the power module 100 further includes an encapsulation layer 60, which is disposed at least on the side opposite to the power chip and the corresponding insulating substrate.

[0090] The encapsulation layer 60 fills within the outer casing 70 to provide stress buffering and protect the aforementioned power chips. The encapsulation layer 60 can be silicone gel for soft encapsulation or molding compound for hard encapsulation.

[0091] In some embodiments, such as Figure 1 and Figure 2As shown, the power module 100 further includes a heat dissipation substrate 301, which is at least disposed on the side of the first insulating substrate 10 opposite to the second insulating substrate 11 and / or on the side of the second insulating substrate 11 opposite to the first insulating substrate 10. The heat dissipation substrate 301 may include, but is not limited to, a copper substrate, an aluminum silicon carbide substrate, etc. The heat dissipation substrate 301 is used to provide mechanical support and structural rigidity, and to improve heat dissipation.

[0092] The power module of this application includes: a first insulating substrate, a second insulating substrate, a plurality of first power chips, a first power terminal, and a first driving terminal; wherein, the first insulating substrate and the second insulating substrate are stacked along a first direction; a first power chip is provided on one side of the first insulating substrate and the second insulating substrate that are opposite to each other; the pass-through terminals of the first power chips on the first insulating substrate and the pass-through terminals of the first power chips on the second insulating substrate are electrically connected to the first power terminal through a first conductive post, and the control terminals of the first power chips on the first insulating substrate and the control terminals of the first power chips on the second insulating substrate are electrically connected to the first driving terminal through a second conductive post, so that the first power chips on the first insulating substrate and the first power chips on the second insulating substrate are arranged in parallel. On the one hand, the first power chip on the first insulating substrate and the first power chip on the second insulating substrate are arranged in parallel, which can improve the current carrying capacity of the power chip and reduce the conduction loss of the power module. On the other hand, the first power chip on the first insulating substrate and the first power chip on the second insulating substrate are arranged along the stacking direction of the first insulating substrate and the second insulating substrate, and are arranged on the side opposite to the first insulating substrate and the second insulating substrate. This can realize the face-to-face stacking of the first power chip, thereby making full use of the space of the power module in the stacking direction, realizing the full utilization of three-dimensional space, and facilitating heat dissipation on both sides of the first power chip in the stacking direction, which can improve the heat dissipation effect of the power module itself and improve the problem of thermal failure. Furthermore, the control terminal and the path terminal of the first power chip are connected to the corresponding terminal through the corresponding conductive post, which can improve the problem of low reliability caused by easy breakage of solder joints when using bonding wire connection.

[0093] This application is based on a novel power module structure design, which breaks through the current design limitations and effectively increases the current carrying capacity of the power module. At the same time, the double-sided heat dissipation structure effectively alleviates the thermal risks of traditional power modules, and the stress symmetrical distribution design effectively improves the reliability of the power module.

[0094] This application can make full use of the space in the vertical direction (first direction z) without increasing the size of the power module in the horizontal direction (xy plane), thereby achieving a greater current carrying capacity of the power module, breaking through the current carrying capacity limitations of the original two-dimensional layout, and realizing full utilization of three-dimensional space.

[0095] This application can integrate a double-sided heat dissipation structure on both the top and bottom of the power module to achieve multiple heat dissipation channels and reduce the risk of local overheating of the chip inside the power module.

[0096] This application eliminates the bonding wire process, and the power chip layout is symmetrical in the three directions of the first direction z, the second direction x, and the third direction y, with symmetrical stress distribution, which is more conducive to improving the reliability of the power module 100.

[0097] This application enables short-term overcurrent capability of power modules without over-sizing, reducing system cost, size, and weight. Furthermore, in some embodiments, it does not require radical changes to the internal structure of traditional power modules, nor does it damage the original bonding method or insulation structure. This solution has low manufacturing difficulty, is easy to implement, and has mass production potential.

[0098] This application's power module increases thermal capacity, ensuring that the junction temperature of the power chip remains within a safe range even under harsh conditions of short-term overcurrent, thereby reducing thermal failure of the power module. At the same time, the reduced junction temperature helps improve the reliability of the power module.

[0099] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A power module, characterized in that, The power module includes: The first insulating substrate and the second insulating substrate are stacked along the first direction; Multiple first power chips are provided on one side of the first insulating substrate and the second insulating substrate that are disposed opposite to each other; The first power terminal and the first drive terminal are connected in parallel. The pass terminal of the first power chip on the first insulating substrate and the pass terminal of the first power chip on the second insulating substrate are electrically connected to the first power terminal through the first conductive post. The control terminal of the first power chip on the first insulating substrate and the control terminal of the first power chip on the second insulating substrate are electrically connected to the first drive terminal through the second conductive post, so that the first power chip on the first insulating substrate and the first power chip on the second insulating substrate are arranged in parallel.

2. The power module according to claim 1, characterized in that, The passage terminal includes a first passage terminal and a second passage terminal, the first conductive post includes a first sub-conductive post and a second sub-conductive post, and the first power terminal includes a first polarity power terminal and a second polarity power terminal. The first access terminal of the first power chip on the first insulating substrate and the first access terminal of the first power chip on the second insulating substrate are electrically connected to the first polar power terminal through the first sub-conductive post. The second path terminal of the first power chip on the first insulating substrate is electrically connected to the upper metal layer of the first insulating substrate, and the second path terminal of the first power chip on the second insulating substrate is electrically connected to the upper metal layer of the second insulating substrate. The upper metal layers of the first insulating substrate and the upper metal layers of the second insulating substrate are electrically connected to the second polarity power terminal through the second sub-conductive post.

3. The power module according to claim 2, characterized in that, The second sub-conductive post is disposed between the first insulating substrate and the second insulating substrate along the first direction, and is located outside the first power chip along the second direction; The first sub-conductive post is located between the first power chip disposed on the first insulating substrate and the first power chip disposed on the second insulating substrate along the first direction; The second direction is perpendicular to the first direction.

4. The power module according to claim 3, characterized in that, The first polarity power terminal, the second polarity power terminal, and the first drive terminal extend in a vertical plane in the first direction. The extension directions of the first polarity power terminal and the second polarity power terminal are opposite to each other, while the extension directions of the first polarity power terminal and the first drive terminal are the same.

5. The power module according to claim 1, characterized in that, The power module also includes: Multiple second power chips are provided on one side of the first insulating substrate and the second insulating substrate that are disposed opposite to each other; The second power terminal and the second drive terminal are connected to the second power terminal via a third conductive post. The control terminal of the second power chip on the first insulating substrate and the control terminal of the second power chip on the second insulating substrate are connected to the second drive terminal via a fourth conductive post, so that the second power chip on the first insulating substrate and the second power chip on the second insulating substrate are arranged in parallel. The first power chip and the second power chip are spaced apart along a third direction, which is perpendicular to the first direction.

6. The power module according to claim 5, characterized in that, Multiple first power chips are provided on both the first insulating substrate and the second insulating substrate, arranged along a second direction; the second direction is perpendicular to the first direction and the third direction, respectively.

7. The power module according to claim 5, characterized in that, The first power terminal includes a first polarity power terminal and a second polarity power terminal, which are electrically connected to the first channel terminal and the second channel terminal of the first power chip, respectively. The second power terminal includes a third polarity power terminal and a fourth polarity power terminal, which are electrically connected to the first channel terminal and the second channel terminal of the second power chip, respectively. The first driving terminal is disposed on the same side as the second driving terminal; the first polarity power terminal is disposed on the same side as the third polarity power terminal; the fourth polarity power terminal is disposed on the same side as the second polarity power terminal, and is disposed on the same side or opposite side to the third polarity power terminal.

8. The power module according to claim 7, characterized in that, The fourth polarity power terminal is the same terminal as the second polarity power terminal or is electrically connected.

9. The power module according to claim 7, characterized in that, The second polarity power terminal and the third polarity power terminal are the same terminal or electrically connected to form an AC terminal.

10. The power module according to any one of claims 1 to 9, characterized in that, The power module also includes: The outer casing is at least disposed on the side of the first insulating substrate opposite to the second insulating substrate and / or on the side of the second insulating substrate opposite to the first insulating substrate; The material of the outer shell includes metal and / or phase change material.

11. The power module according to claim 10, characterized in that, The outer shell uses the metal as a frame and is filled with the phase change material.

12. The power module according to claim 10, characterized in that, The thickness of the outer shell is greater than or equal to 13 mm.

13. The power module according to claim 10, characterized in that, The outer casing is provided with a mounting through hole, and the power module further includes a fifth conductive post and an insulating ring. The fifth conductive post is partially disposed within the mounting through hole, and the insulating ring is disposed at least between the inner wall of the mounting through hole and the fifth conductive post.

14. The power module according to any one of claims 1 to 9, characterized in that, The power module also includes: A heat dissipation component is disposed at least on the side of the first insulating substrate opposite to the second insulating substrate and / or on the side of the second insulating substrate opposite to the first insulating substrate.

15. The power module according to claim 14, characterized in that, The heat dissipation components include a cold plate, an air-cooled radiator, or a water-cooled radiator.

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