Power module, preparation method thereof and power supply circuit

Abstract

The invention discloses a power module, a preparation method thereof and a power supply circuit, and belongs to the technical field of semiconductor packaging. The power module includes: a first metal-clad substrate; a second metal layer-coated substrate, wherein the second metal layer-coated substrate and the first metal layer-coated substrate are oppositely arranged; the plurality of power chips are positioned between the first substrate coated with the metal layer and the second substrate coated with the metal layer; a first pressureless sintering layer, wherein the first pressureless sintering layer is arranged between the power chip and the first metal-coated substrate or the second metal-coated substrate; and the supporting layer is arranged on one side, far away from the first pressureless sintering layer, of the power chip. According to the technical scheme, the pressureless sintering process is adopted, so that large-batch production of the power module with high heat dissipation performance and high conductivity can be realized.

Description

Technical Field

[0001] The present application belongs to the field of semiconductor packaging technology, and in particular, relates to a power module and a preparation method thereof and a power supply circuit. Background Art

[0002] At present, the packaging structure of power chips includes single-sided cooling technology and double-sided cooling technology. The single-sided cooling technology of power modules means that a DBC substrate is only provided on one side of the power chip in the power module to cool the heat generated by the power chip during operation. The double-sided cooling technology of power modules means that a DBC substrate is provided on both sides of the power chip in the power module.

[0003] Compared with the double-sided cooling technology of the power module, the single-sided cooling technology of the power module can only dissipate heat from the power chip through a DBC substrate, and the heat dissipation effect is poor. In the single-sided cooling technology of the power module, the power chip conducts electrical and thermal conduction with the DBC substrate through the bonding wire, which not only introduces large parasitic capacitance and inductance, affecting the transmission of the power chip signal, but also easily breaks, thereby causing damage to the power module, thereby reducing the reliability of the power module.

[0004] However, in the power module using the double-sided cooling technology, although DBC substrates are provided on both sides of the power chip, thereby improving the stability of the power module structure, the double-sided cooling technology uses silver pressing sintering, and the thickness of the silver paste (adhesive layer) after sintering is uneven. Therefore, during the silver pressing sintering process, when pressure is applied to the silver paste, the DBC substrates on both sides of the power chip are easily warped, which leads to poor connection of the power module, thereby causing electrical failures, poor heat dissipation, and mechanical stress in the power module. Summary of the invention

[0005] The present application provides a power module and a preparation method thereof and a power circuit, aiming to realize mass production of power modules with high heat dissipation performance and high conductivity by adopting a pressureless sintering process.

[0006] In a first aspect, the present application provides a power module, including:

[0007] a first metal-clad substrate;

[0008] a second metal-clad substrate, the second metal-clad substrate being arranged opposite to the first metal-clad substrate;

[0009] A plurality of power chips, wherein the plurality of power chips are located between the first metal-clad substrate and the second metal-clad substrate;

[0010] a first pressureless sintering layer, wherein the first pressureless sintering layer is disposed between the power chip and the first metal-clad substrate or the second metal-clad substrate;

[0011] A support layer is provided on a side of the power chip away from the first pressureless sintering layer.

[0012] In some embodiments, a second pressureless sintering layer is provided between the power chip and the support layer.

[0013] In some embodiments, a third pressureless sintering layer is disposed between the support layer and the first metal-clad substrate or the second metal-clad substrate.

[0014] In some embodiments, the material of the first pressureless sintering layer, the second pressureless sintering layer and the third pressureless sintering layer includes at least one of silver and copper; and / or,

[0015] The thickness of the first pressureless sintered layer, the second pressureless sintered layer and the third pressureless sintered layer is in the range of [80 μm, 120 μm].

[0016] In some embodiments, the material of the support layer is a conductive material.

[0017] In some embodiments, the plurality of power chips include at least a first power chip and a second power chip;

[0018] One of the first power chips and one of the second power chips form a half bridge, and the two power chips in the same half bridge have commutation paths in opposite directions between the first metal-clad substrate and the second metal-clad substrate.

[0019] In some embodiments, the plurality of power chips include at least a first power chip and a second power chip;

[0020] Two of the first power chips and two of the second power chips are connected in parallel to form a full bridge. The first power chip and the second power chip in the same full bridge have opposite directions of commutation paths between the first metal-clad substrate and the second metal-clad substrate.

[0021] In some embodiments, the plurality of power chips include a first power chip and a second power chip;

[0022] A plurality of the first power chips and a plurality of the second power chips are connected in parallel to form a multi-chip parallel half-bridge or a multi-chip parallel full-bridge, and the first power chip and the second power chip in the same multi-chip parallel half-bridge or the multi-chip parallel full-bridge have opposite directions of the commutation paths between the first metal-clad substrate and the second metal-clad substrate.

[0023] An embodiment of the present application provides a power module using double-sided cooling technology, that is, a first metal-clad substrate and a second metal-clad substrate are respectively arranged on both sides of a power chip. This arrangement can not only improve the stability of the power module structure, but also achieve the effect of double-sided heat dissipation of the power chip in the power module through the first metal-clad substrate and the second metal-clad substrate on both sides.

[0024] In addition, in the present application, the double-sided cooling technology adopts a pressureless sintering process (for example, pressureless silver sintering, pressureless copper sintering), which can realize the electrical conduction and thermal conduction of the power chip in the power module, and significantly reduce the contact resistance between the power chip in the power module and the first metal layer substrate and the second metal layer substrate, thereby improving the electrical conductivity and thermal conductivity between the power chip in the power module and the first metal layer substrate and the second metal layer substrate.

[0025] In the embodiment of the present application, the silver paste or copper paste in the pressureless sintering process can be adhered to the surface of the first metal-clad substrate, the second metal-clad substrate or the power chip by printing or dispensing, thereby achieving pressureless sintering of multiple power modules with substrates of different heights at the same time.

[0026] Furthermore, the support layer can provide a safe insulation distance between the first metal-clad substrate and the second metal-clad substrate, and can compensate for the warping of the first metal-clad substrate and / or the second metal-clad substrate caused by the different thicknesses of the pressureless sintering layers (the first pressureless sintering layer, the second pressureless sintering layer, and the third pressureless sintering layer) after sintering, thereby achieving good electrical conductivity and thermal conductivity between the power chip in the power module and the first metal-clad substrate and the second metal-clad substrate.

[0027] In addition, the present application adopts a pressureless sintering process to prepare a power module capable of double-sided heat dissipation, and the preparation process is simple and can be mass-produced.

[0028] On the other hand, the present application also provides a method for preparing a power module, comprising:

[0029] Using a screen printing process, uniformly printing silver paste or copper paste on the first surface of the first metal-clad substrate;

[0030] Attaching the first surface of the power chip to the first surface of the first metal-clad substrate to perform a first pressureless sintering;

[0031] Using a screen printing process, uniformly printing silver paste or copper paste on the second surface of the power chip;

[0032] Attaching the first surface of the support layer to the second surface of the power chip to perform a second pressureless sintering;

[0033] Using a screen printing process, uniformly printing silver paste or copper paste on the second surface of the support layer to obtain a sample;

[0034] The side of the sample printed with silver paste or copper paste is bonded to the side of another sample printed with silver paste or copper paste, and a third pressureless sintering is performed to obtain the power module.

[0035] On the other hand, the present application further provides a power supply circuit, comprising a circuit board and a power module as described in the above embodiment, wherein the power module is electrically connected to the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0037] Figure 1A A structural schematic diagram of a power module provided for related technology.

[0038] Figure 1B A schematic diagram of the structure of another power module provided for related technology.

[0039] Figure 2A A schematic diagram of the structure of a power module provided in an embodiment of the present application.

[0040] Figure 2B for Figure 2A A schematic diagram of the internal current direction of a power module provided in an embodiment.

[0041] Figure 3 A schematic diagram of the structure of a full-bridge power module provided in an embodiment of the present application.

[0042] Figure 4 A schematic diagram of the structure of a multi-chip parallel power module provided in an embodiment of the present application.

[0043] Figure 5 A schematic flow chart of a method for preparing a half-bridge power module provided in an embodiment of the present application.

[0044] Figure 6 A schematic diagram of a process of preparing a half-bridge power module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments provided by the present application, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present application.

[0046] Unless the context requires otherwise, throughout the specification and claims, the term "comprising" is to be construed in an open, inclusive sense, ie, meaning "including, but not limited to."

[0047] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, unless otherwise specified, "plurality" means two or more.

[0048] When describing some embodiments, the term "connection" and its derivative expressions may be used. The term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For example, when describing some embodiments, the term "connection" may be used to indicate that two or more components are in direct physical or electrical contact with each other.

[0049] Additionally, the use of “based on” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values ​​may, in practice, be based on additional conditions or values ​​beyond those stated.

[0050] It will be understood that when a layer or an element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present between the layer or element and the other layer or substrate.

[0051] Exemplary embodiments are described herein with reference to cross-sectional views that are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are conceivable. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but include deviations in shape due to, for example, manufacturing. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device, and are not intended to limit the scope of the exemplary embodiments.

[0052] Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0053] As the performance requirements of power modules for applications such as electric vehicles, renewable energy, and industrial motor drives increase, the market demand for power modules (e.g., SiC modules) is increasing. However, traditional electrical interconnection technologies (e.g., soldering technology) can no longer meet the performance requirements of power modules in high-frequency and high-temperature environments.

[0054] At present, silver sintering technology provides an interconnection solution with high electrical conductivity, high thermal conductivity and high reliability. Since high-power density power modules generate a lot of heat during operation, silver sintering technology is applied to the electrical connection of power modules. At this time, the double-sided cooling of silver sintering technology can dissipate the large amount of heat generated by the power module during operation, thereby improving the thermal conduction efficiency of the power module and reducing the thermal resistance of the power module, so as to improve the overall performance and reliability of the power module.

[0055] Figure 1A A schematic diagram of the structure of a power module provided by related technology 1, such as Figure 1A As shown, the power module includes: a heat dissipation layer 1e, a DBC substrate 1a, and a power chip 1c. The DBC substrate 1a is bonded to the heat dissipation layer 1e through a first bonding layer 1d. The power chip 1c is arranged on a side of the DBC substrate 1a away from the heat dissipation layer 1e. Furthermore, the power chip 1c is bonded to the DBC substrate 1a through a second bonding layer 1b.

[0056] like Figure 1A As shown, the power module further includes bonding wires 1m and a packaging layer 1f. The bonding wires 1m may be made of aluminum or copper, and are used to achieve electrical and thermal conduction between the power chip 1c and the DBC substrate 1a.

[0057] Furthermore, the first bonding layer 1d and the second bonding layer 1b can be made into bonding layers by using silver sintering technology, and silver paste or solder paste can be made into bonding layers through a high-temperature sintering process.

[0058] Among them, in related technology 1, under a certain temperature and pressure, the power chip 1c and the DBC substrate 1a, as well as the DBC substrate 1a and the heat dissipation layer 1e are sintered through silver sintering technology. During the sintering process, the organic binder in the silver paste will decompose and volatilize, and solid diffusion or liquid sintering will occur between the silver powder particles in the silver paste to form a dense silver layer, which can achieve metallurgical bonding between the power chip 1c and the DBC substrate 1a, as well as the DBC substrate 1a and the heat dissipation layer 1e, thereby achieving good electrical conductivity and thermal conductivity between the power chip 1c and the DBC substrate 1a and the heat dissipation layer 1e.

[0059] However, in the related art 1, the heat generated by the power chip 1c can only be cooled on one side through the DBC substrate 1a and the heat dissipation layer 1e, and the heat dissipation effect is poor compared to the double-sided heat dissipation effect.

[0060] In addition, in the related technology 1, the power module realizes electrical conduction and thermal conduction between the power chip 1c and the DBC substrate 1a by setting bonding wires 1m. This setting method introduces large parasitic inductance and capacitance, which will affect the transmission effect of the power module signal.

[0061] Moreover, during the reliability test of the power module, the bonding wire 1m is more likely to break than the power chip and the DBC substrate, which may lead to damage to the power module, thereby reducing the reliability of the power module.

[0062] Figure 1B A schematic diagram of a power module provided by related technology 2, such as Figure 1B As shown, the power module includes: a first DBC substrate 1A and a second DBC substrate 1B that are arranged opposite to each other, and a power chip 1C located between the first DBC substrate 1A and the second DBC substrate 1B.

[0063] The first DBC substrate 1A includes a first copper layer, a silicon nitride layer, and a second copper layer stacked in sequence, and / or the second DBC substrate 1B includes a first copper layer, a silicon nitride layer, and a second copper layer stacked in sequence.

[0064] The power module further includes an interposer 1D, a first press-sintered layer 1F, a second press-sintered layer 1G, and a third press-sintered layer 1E. The interposer is located between the first DBC substrate and the second DBC substrate, and is disposed on a side of the power chip away from the first DBC substrate.

[0065] Furthermore, a first press-sintered layer 1F is provided between the interposer 1D and the power chip 1C. The first press-sintered layer 1F is provided between the interposer 1D and the power chip 1C, which can not only be used to provide an electrical connection between the power chip 1C and the interposer 1D, thereby ensuring that the current can flow smoothly from the power chip 1C to the external circuit, but also can be used to conduct a large amount of heat generated by the power chip 1C during operation to the interposer 1D, and then dissipate it to the surrounding environment, thereby maintaining the power chip 1C operating at a safe operating temperature.

[0066] like Figure 1B As shown, a second press-sintered layer 1G is provided between the power chip 1C and the first DBC substrate 1A, and a third press-sintered layer 1E is provided between the interposer 1D and the second DBC substrate 1B. The second press-sintered layer 1G and the third press-sintered layer 1E are provided mainly to achieve electrical conduction and thermal conduction between the power chip 1C and the interposer 1D, the first DBC substrate 1A, and the second DBC substrate 1B.

[0067] Among them, the material of the first press-sintered layer 1F can be at least one of silver paste, copper paste and silver film, and / or the material of the second press-sintered layer 1G can be at least one of silver paste, copper paste and silver film, and / or the material of the third press-sintered layer 1E can be at least one of silver paste, copper paste and silver film.

[0068] Among them, related technology 2 adopts a double-sided sintering process. In the process of double-sided sintering, the use of silver paste is a common method, especially in the electronic packaging of power modules. Silver paste has become a commonly used material in double-sided sintering due to its excellent electrical conductivity and thermal conductivity, as well as relatively low cost.

[0069] For example, in related technology 2, although DBC substrates are provided on both sides of the power chip 1C, the stability of the power module structure and the heat dissipation effect of the power module can be improved. However, the double-sided sintering process adopts pressed silver sintering, and the thickness of the silver paste (adhesive layer) after sintering is uneven. Therefore, during the pressed silver sintering process, when pressure is applied to the silver paste, it is easy to cause the first DBC substrate 1A and / or the second DBC substrate 1B on both sides of the power chip 1C to warp, or cause damage to the power chip, and then cause poor connection of the power module, thereby causing electrical failures, poor heat dissipation, and mechanical stress in the power module.

[0070] In the related art 2, the use of pressure sintering silver requires special equipment (e.g., a pressurizing device), the processing technology is complicated, and substrates of different heights in the same DBC substrate cannot be sintered. Since special equipment is used, the flatness of the substrate is required to be high, and mass production is not possible.

[0071] In addition, the existing double-sided cooling packaging structure can also use soldering technology in addition to the pressure sintering silver technology. However, in soldering technology, the thermal conductivity of tin is low, which will affect the heat dissipation performance of the power module, and the mechanical strength of the solder joints after curing is insufficient, which will lead to easy failure under mechanical stress. In addition, during the reliability test of the power module, the solder joints will gradually degrade, which will lead to a decrease in the reliability of the power module.

[0072] To solve at least one of the above problems, the present application provides a power module, a preparation method thereof, and a power circuit.

[0073] Figure 2A A schematic diagram of a power module provided in an embodiment of the present application is shown in FIG. Figure 2A As shown, the present application provides a power module, which includes a first metal-clad substrate 1, a second metal-clad substrate 2, and a plurality of power chips 3 arranged between the first metal-clad substrate 1 and the second metal-clad substrate 2. The second metal-clad substrate 2 is arranged opposite to the first metal-clad substrate 2.

[0074] Furthermore, the power module further includes a first pressureless sintering layer 3 and a support layer 7. In the embodiment of the present application, the material of the support layer 7 is a conductive material. For example, the material of the support layer 7 includes one or more of various metals such as copper and platinum or alloys thereof.

[0075] In the embodiment of the present application, when the material of the support layer 7 is copper, the support layer 7 and the second pressureless sintering layer 5 and the third pressureless sintering layer 6 not only have lower contact resistance and thermal conductivity, but also have strong current transmission capability. Therefore, at this time, the support layer 7 can effectively dissipate heat for the power chip 3, thereby reducing the operating temperature of the power chip 3 and exerting the excellent performance of the power chip.

[0076] In the embodiment of the present application, the structure of the second pressureless sintered layer 5-support layer 7-third pressureless sintered layer 6 has high stability and durability, thereby ensuring that the power chip can work at high load for a long time, and helping to improve the reliability and excellent performance of the overall power module system.

[0077] In addition, compared with the related art 1, the support layer 7 in the power module of the embodiment of the present application is used to replace the bonding wire 1m in the related art 1, which can reduce parasitic inductance and capacitance. Parasitic inductance and capacitance will not only cause the frequency response of the power chip 3 to change, but also cause signal delay and distortion of the power chip 3, thereby affecting the stability of the power module under high-frequency operation.

[0078] Furthermore, the high heat dissipation capability of the support layer 7 in the present application can fully exert the electrical performance and thermal management capability of the power module.

[0079] like Figure 2A As shown, the first pressureless sintering layer 4 is disposed between the power chip 3 and the first metal-clad substrate 1 or the second metal-clad substrate 2 , and the support layer 7 is disposed on a side of the power chip 3 away from the first pressureless sintering layer 4 .

[0080] The embodiment of the present application provides a power module adopting double-sided cooling technology, that is, a first metal-clad substrate 1 and a second metal-clad substrate 2 are respectively arranged on both sides of the power chip. This arrangement can not only improve the stability of the power module structure, but also achieve the effect of double-sided heat dissipation of the power chip 3 in the power module through the first metal-clad substrate 1 and the second metal-clad substrate 2 on both sides.

[0081] In addition, in the present application, the double-sided cooling technology adopts a pressureless sintering process (pressureless silver sintering, pressureless copper sintering), which can realize the electrical conduction and thermal conduction of the power chip 3 in the power module, and significantly reduce the contact resistance between the power chip 3 in the power module and the first metal-clad substrate 1 and the second metal-clad substrate 2, thereby improving the electrical conductivity and thermal conductivity between the power chip 3 in the power module and the first metal-clad substrate 1 and the second metal-clad substrate 2.

[0082] In the embodiment of the present application, the silver paste or copper paste in the pressureless sintering process can be adhered to the surface of the first metal-clad substrate 1, the second metal-clad substrate 2 or the power chip 3 by printing or dispensing, thereby realizing the pressureless sintering of multiple power modules with substrates of different heights at the same time.

[0083] Furthermore, the support layer 7 can provide a safe insulation distance between the first metal-clad substrate 1 and the second metal-clad substrate 2, and can compensate for the warping of the first metal-clad substrate 1 and / or the second metal-clad substrate 2 caused by the different thicknesses of the pressureless sintering layers (the first pressureless sintering layer 4, the second pressureless sintering layer 5, and the third pressureless sintering layer 6) after sintering, thereby achieving good electrical conductivity and thermal conductivity between the power chip 3 and the first metal-clad substrate 1 and the second metal-clad substrate 2 in the power module.

[0084] In addition, the present application adopts a pressureless sintering process to prepare a power module capable of double-sided heat dissipation, and the preparation process is simple and can be mass-produced.

[0085] In some embodiments, Figure 2A As shown, the power module further includes a second pressureless sintering layer 5 , and the second pressureless sintering layer 5 is arranged between the power chip 3 and the support layer 7 .

[0086] In the embodiment of the present application, a pressureless sintering process is used to form a dense sintered body between the power chip 3 and the support layer 7, that is, the second pressureless sintered layer 5, which can not only achieve a reliable connection between the power chip 3 and the support layer 7, but also effectively transfer the heat generated by the power chip 3 to the support layer 7, and then dissipate it through the first metal-clad substrate 1 and / or the second metal-clad substrate 2.

[0087] In addition, compared with the pressure sintering process used in the related art, the pressureless sintering technology used in this application does not require external pressure, which can simplify the packaging process of power chips and reduce production costs. At the same time, the pressureless sintering technology can also realize the simultaneous pressureless sintering of multiple power modules with substrates of different heights.

[0088] In some embodiments, Figure 2A As shown, the power module further includes a third pressureless sintered layer 6 , and the third pressureless sintered layer 6 is disposed between the support layer 7 and the first metal-clad substrate 1 or the second metal-clad substrate 2 .

[0089] In the embodiment of the present application, a pressureless sintering process is utilized to form a dense sintered body between the support layer 7 and the first metal-clad substrate 1 or the second metal-clad substrate 2, that is, the third pressureless sintered layer 6, which can not only realize a reliable connection between the support layer 7 and the first metal-clad substrate 1 or the second metal-clad substrate 2, but also effectively transfer the heat generated by the power chip 3 to the first metal-clad substrate 1 and / or the second metal-clad substrate 2 through the support layer 7, and dissipate it.

[0090] In some embodiments, Figure 2A As shown, the material of the first pressureless sintered layer 4 , the second pressureless sintered layer 5 and the third pressureless sintered layer 6 includes at least one of silver and copper.

[0091] In some embodiments, Figure 2A As shown, the thickness of the first pressureless sintered layer 4 , the second pressureless sintered layer 5 and the third pressureless sintered layer 6 is in the range of [80 μm, 120 μm].

[0092] For example, in one example, the thickness of the first pressureless sintered layer 4 can be 80μm, 85μm, 90μm, 95μm, 100μm, 105μm, 110μm, 115μm, 120μm; the thickness of the second pressureless sintered layer 5 can be 80μm, 85μm, 90μm, 95μm, 100μm, 105μm, 110μm, 115μm, 120μm; the thickness of the third pressureless sintered layer 6 can be 80μm, 85μm, 90μm, 95μm, 100μm, 105μm, 110μm, 115μm, 120μm.

[0093] In the embodiment of the present application, the thickness range of the first pressureless sintered layer 4, the second pressureless sintered layer 5 and the third pressureless sintered layer 6 is between 80μm and 120μm, which can not only significantly improve the thermal conductivity of the power module, but also enhance the connection reliability between the power chip 3 in the power module and the first metal-clad substrate 1 and / or the second metal-clad substrate 2.

[0094] Figure 2B for Figure 2A The schematic diagram of the internal current direction of the power module provided in the embodiment is as follows: Figure 2B As shown, in some embodiments, the multiple power chips include at least a first power chip 3a and a second power chip 3b, and a first power chip 3a and a second power chip 3b form a half bridge, and the two power chips located in the same half bridge have opposite directions of the commutation paths between the first metal-clad substrate 1 and the second metal-clad substrate 2.

[0095] Figure 3 A schematic diagram of the structure of a full-bridge power module provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, in some embodiments, the plurality of power chips include at least a first power chip 3a and a second power chip 3b;

[0096] Two first power chips 3a and two second power chips 3b are connected in parallel to form a full bridge. The first power chips 3a and the second power chips 3b in the same full bridge have opposite directions of commutation paths between the first metal-clad substrate 1 and the second metal-clad substrate 2.

[0097] Figure 4 A schematic diagram of a multi-chip parallel power module provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, in some embodiments, the multiple power chips include a first power chip and a second power chip, and the multiple first power chips 3a and the multiple second power chips 3b are connected in parallel to form a multi-chip parallel half-bridge or a multi-chip parallel full-bridge, and the first power chip 3a and the second power chip 3b in the same multi-chip parallel half-bridge or multi-chip parallel full-bridge have opposite directions of the commutation paths between the first metal-clad substrate 1 and the second metal-clad substrate 2.

[0098] Figure 5 A schematic diagram of a process for preparing a half-bridge power module provided in an embodiment of the present application is provided. Figure 6 A process diagram of a method for preparing a half-bridge power module provided in an embodiment of the present application is shown in FIG. Figure 5 and Figure 6 As shown, the method comprises the following steps:

[0099] Step S1: using a screen printing process to uniformly print silver paste or copper paste on a first surface of a first metal-clad substrate.

[0100] Step S2: attaching the first surface of the power chip to the first surface of the first metal-clad substrate, and performing a first pressureless sintering.

[0101] Step S3: using a screen printing process to uniformly print silver paste or copper paste on the second surface of the power chip.

[0102] Step S4: attaching the first surface of the support layer to the second surface of the power chip, and performing a second pressureless sintering.

[0103] Step S5: Using a screen printing process, uniformly print silver paste or copper paste on the second surface of the support layer to obtain a sample.

[0104] Step S6: Bond one side of the sample printed with silver paste or copper paste to another side of the sample printed with silver paste or copper paste, and perform a third pressureless sintering to obtain a power module.

[0105] The power module provided in the present application can be applied to a power circuit. For example, in one example, the power circuit includes a power module and a circuit board, and the power module is electrically connected to the circuit board for power conversion, voltage regulation, power amplification, current control and protection, and thermal management and heat dissipation.

[0106] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that a person skilled in the art can think of within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A power module, characterized in that: include: a first metal-clad substrate; a second metal-clad substrate, the second metal-clad substrate being arranged opposite to the first metal-clad substrate; A plurality of power chips, wherein the plurality of power chips are located between the first metal-clad substrate and the second metal-clad substrate; a first pressureless sintering layer, wherein the first pressureless sintering layer is disposed between the power chip and the first metal-clad substrate or the second metal-clad substrate; A support layer is provided on a side of the power chip away from the first pressureless sintering layer.

2. The power module according to claim 1, characterized in that: Also includes: A second pressureless sintering layer is disposed between the power chip and the supporting layer.

3. The power module according to claim 2, characterized in that: Also includes: A third pressureless sintering layer is disposed between the support layer and the first metal-clad substrate or the second metal-clad substrate.

4. The power module according to claim 3, characterized in that: The material of the first pressureless sintering layer, the second pressureless sintering layer and the third pressureless sintering layer includes at least one of silver and copper; and / or, The thickness of the first pressureless sintered layer, the second pressureless sintered layer and the third pressureless sintered layer is in the range of [80 μm, 120 μm].

5. The power module according to claim 1, characterized in that: The material of the support layer is a conductive material.

6. The power module according to claim 1, characterized in that: The plurality of power chips include at least a first power chip and a second power chip; One of the first power chips and one of the second power chips form a half bridge, and the two power chips in the same half bridge have commutation paths in opposite directions between the first metal-clad substrate and the second metal-clad substrate.

7. The power module according to claim 1, characterized in that: The plurality of power chips include at least a first power chip and a second power chip; Two of the first power chips and two of the second power chips are connected in parallel to form a full bridge. The first power chip and the second power chip in the same full bridge have opposite directions of commutation paths between the first metal-clad substrate and the second metal-clad substrate.

8. The power module according to claim 1, characterized in that: The plurality of power chips include a first power chip and a second power chip; A plurality of the first power chips and a plurality of the second power chips are connected in parallel to form a multi-chip parallel half-bridge or a multi-chip parallel full-bridge, and the first power chip and the second power chip in the same multi-chip parallel half-bridge or the multi-chip parallel full-bridge have opposite directions of the commutation paths between the first metal-clad substrate and the second metal-clad substrate.

9. A method for preparing a power module, characterized in that: include: Using a screen printing process, uniformly printing silver paste or copper paste on the first surface of the first metal-clad substrate; Attaching the first surface of the power chip to the first surface of the first metal-clad substrate to perform a first pressureless sintering; Using a screen printing process, uniformly printing silver paste or copper paste on the second surface of the power chip; Attaching the first surface of the support layer to the second surface of the power chip to perform a second pressureless sintering; Using a screen printing process, uniformly printing silver paste or copper paste on the second surface of the support layer to obtain a sample; The side of the sample printed with silver paste or copper paste is bonded to the side of another sample printed with silver paste or copper paste, and a third pressureless sintering is performed to obtain the power module.

10. A power supply circuit, characterized in that: It comprises a circuit board and a power module as claimed in any one of claims 1 to 9, wherein the power module is electrically connected to the circuit board.

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