Double-sided direct cooling power module

Abstract

The invention relates to the field of power electronic devices, in particular to a double-face direct cooling power module which comprises a first chip, a second chip, a first radiator, a second radiator, a first substrate and a second substrate, the first substrate and the second substrate are oppositely arranged, and the first chip is electrically connected to the second face of the first substrate. The first surface of the first substrate is connected with the first radiator; the second chip is electrically connected to the first face of the second substrate, and the second face of the second substrate is connected with the second radiator. The heat dissipation efficiency of the two oppositely arranged substrates can be balanced, the bottleneck problem of uneven temperature distribution in the use process of the power module is solved, meanwhile, parasitic parameters of the power module are reduced, and the purposes of improving the power density, reducing the switching loss and improving the working frequency are achieved.

Description

Technical Field

[0001] The invention relates to the field of power electronic devices, and in particular to a double-sided direct cooling power module. Background Art

[0002] The heat dissipation form of traditional power modules is single-sided cooling. The heat generated during the switching and conduction of the power chip can only be transferred to the heat dissipation base plate from a single direction. This cooling form seriously limits the improvement of the power density of the power module and hinders the development of miniaturization of the power module. In order to improve the cooling effect and increase the power density of the power module, the concept of double-sided cooling came into being. In this type of package, heat can be transferred from the chip to the upper and lower directions. For example: CN117810182A discloses a double-sided heat dissipation module based on terminal interconnection, a manufacturing method and an apparatus.

[0003] With the advancement of technology, double-sided cooling power modules have been developed and applied in recent years. However, in actual use, thermal grease (indirect cooling) needs to be applied between the double-sided substrate and the heat sink, resulting in extremely limited improvement in module power density. Based on the above shortcomings of double-sided indirect cooling power modules, related technologies have proposed double-sided direct cooling power modules. However, in this solution, the chips are arranged on one side of the substrate. This arrangement will lead to a huge difference in heat flux between the upper and lower substrates, and the advantages of double-sided heat dissipation cannot be fully utilized, and the parasitic inductance is large.

[0004] Therefore, it is urgent to develop a new type of double-sided direct cooling power module. Summary of the invention

[0005] The purpose of the present invention is to provide a double-sided direct cooling power module, which can balance the heat dissipation efficiency of two relatively arranged substrates, improve the bottleneck problem of uneven temperature distribution during the use of the power module, and at the same time reduce the parasitic parameters of the power module, thereby achieving the purpose of improving power density, reducing switching losses, and increasing operating frequency.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows: The present invention provides a double-sided direct cooling power module, comprising a first chip, a second chip, a first heat sink, a second heat sink, and a first substrate and a second substrate arranged opposite to each other, wherein the first chip is electrically connected to the second surface of the first substrate, and the first surface of the first substrate is connected to the first heat sink; the second chip is electrically connected to the first surface of the second substrate, and the second surface of the second substrate is connected to the second heat sink.

[0007] Furthermore, the first chip is connected to the second surface of the first substrate through a first connection layer and / or a binding wire, and the second chip is connected to the first surface of the second substrate through a second connection layer and / or a binding wire.

[0008] Furthermore, the first connection layer and the second connection layer are independently made of solder or silver sintering layer; and the material of the binding wire is aluminum or copper.

[0009] Furthermore, the first heat sink is connected to the first surface of the first substrate through a third connecting layer, and the second heat sink is connected to the second surface of the second substrate through a fourth connecting layer; the third connecting layer and the fourth connecting layer are independently solder, silver sintering layer or copper sintering layer.

[0010] Furthermore, the first chip and the second chip are independently silicon-based IGBT chips, silicon-based FRD chips or silicon carbide-based MOSFET chips.

[0011] Furthermore, the first substrate and the second substrate are both three-layer composite structures, and the first substrate or the second substrate comprises a conductive metal layer located at the upper and lower parts and an insulating ceramic layer located in the middle of the interlayer; The material of the conductive metal layer is copper; the material of the insulating ceramic layer is alumina ceramic, aluminum nitride ceramic or silicon nitride ceramic.

[0012] Further, it includes a pad, the pad includes a fifth connection layer, a conductive layer and a sixth connection layer, the fifth connection layer is connected to the second surface of the first substrate, the sixth connection layer is connected to the first surface of the second substrate, and the conductive layer is connected between the fifth connection layer and the sixth connection layer; The material of the fifth connection layer and the sixth connection layer is solder or silver sintered layer; the material of the conductive layer is copper or molybdenum-copper alloy.

[0013] Furthermore, it also includes pins, which are connected to the first substrate and / or the second substrate.

[0014] Furthermore, the first radiator and the second radiator include a plurality of cooling medium flow channels connected in parallel.

[0015] Furthermore, a plurality of first radiators and a plurality of second radiators are connected in parallel in the cooling flow path.

[0016] The present invention has the following unexpected beneficial effects: 1. The present invention electrically connects the first chip to the second surface of the first substrate, the first surface of the first substrate is connected to the first heat sink, and the second chip is electrically connected to the first surface of the second substrate, and the second surface of the second substrate is connected to the second heat sink, that is, the first chip and the second chip are arranged on the first substrate and the second substrate respectively, so that the heat dissipation efficiency of the relatively arranged first substrate and the second substrate is balanced, the heat dissipation performance of the double-sided direct cooling power module is fully utilized, the heat dissipation efficiency is improved, and the parasitic inductance of the power module is reduced.

[0017] 2. The present invention improves the temperature difference of the power module during use by connecting a plurality of first radiators and a plurality of second radiators in parallel in the cooling flow path, improves the problem of uneven temperature distribution during use of the power module, and improves the efficiency and reliability of the overall system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic structural diagram of the double-sided direct cooling power module of the present invention is shown.

[0019] Figure 2 An exploded view of the double-sided direct cooling power module of the present invention is shown.

[0020] Figure 3 A schematic diagram showing the connection between the double-sided direct cooling power module and the cooling flow path of the present invention is shown.

[0021] Figure 4 The figure shows the cooling medium flow diagram of the double-sided direct cooling power module of the present invention.

[0022] In the figure, 1 is a first chip, 2 is a second chip, 3 is a first substrate, 4 is a second substrate, 5 is a first heat sink, 6 is a second heat sink, 7 is a first connection layer, 8 is a second connection layer, 9 is a binding line, 10 is a third connection layer, 11 is a fourth connection layer, 12 is a pad, and 13 is a pin. DETAILED DESCRIPTION

[0023] The following will describe the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention, not for limiting the scope of protection of the present invention.

[0024] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0025] In one embodiment, see Figure 1 and Figure 2As shown, the present invention provides a double-sided direct cooling power module, comprising a first chip 1, a second chip 2, a first heat sink 5, a second heat sink 6, and a first substrate 3 and a second substrate 4 arranged opposite to each other, wherein the first chip 1 is electrically connected to the second surface of the first substrate 3, and the first surface of the first substrate 3 is connected to the first heat sink 5. The second chip 2 is electrically connected to the first surface of the second substrate 4, and the second surface of the second substrate 4 is connected to the second heat sink 6.

[0026] In this arrangement, the first chip 1 and the second chip 2 are electrically connected to the first substrate 3 and the second substrate 4 respectively, so that the heat dissipation efficiency of the first substrate 3 and the second substrate 4 arranged relatively is balanced, which solves the problem of the huge difference in heat flux between the upper and lower substrates caused by the chip being arranged on only one side of the substrate in the prior art, and gives full play to the heat dissipation performance of the double-sided direct cooling power module, improving the heat dissipation efficiency. At the same time, the parasitic inductance of the power module is reduced, the reliability of the power module is improved, and the failure caused by overheating or excessive parasitic inductance is reduced.

[0027] Illustratively, in the present application, the first surface is the upper end and the second surface is the lower end.

[0028] In a preferred embodiment, see Figure 2 As shown, the first chip 1 is connected to the second surface of the first substrate 3 through a first connection layer 7 and a binding wire 9 , and the second chip 2 is connected to the first surface of the second substrate 4 through a second connection layer 8 and a binding wire 9 .

[0029] The first connection layer 7 or the binding wire 9 is responsible for transmitting the electrical signal on the first chip 1 to the first substrate 3, ensuring the integrity and accuracy of the signal. The second connection layer 8 or the binding wire 9 is responsible for transmitting the electrical signal on the second chip 2 to the second substrate 4, also ensuring the stable transmission of the signal.

[0030] In addition to electrical connection, the first connection layer 7 and the second connection layer 8 also play a role in heat conduction. They can effectively conduct the heat generated on the chip to the first substrate 3 and the second substrate 4, and then dissipate it to the external environment through the first heat sink 5 and the second heat sink 6.

[0031] The first connection layer 7 and the second connection layer 8 also provide a certain mechanical support, which helps to maintain a stable connection between the first chip 1 and the first substrate 3, and between the second chip 2 and the second substrate 4, and prevent the connection from loosening or failing due to vibration or temperature changes.

[0032] The first connection layer 7, the second connection layer 8 or the binding wire 9 can be selected and adjusted according to different application requirements, such as material selection, thickness control and connection method optimization, so as to meet the design requirements of different power modules.

[0033] Furthermore, the first connection layer 7 and the second connection layer 8 are independently made of solder or silver sintered layers. These materials have good electrical conductivity and thermal conductivity and can effectively transmit electrical signals and heat.

[0034] The bonding wire 9 is made of thin metal wire (such as aluminum wire or copper wire), and is connected to the chip and the substrate by ultrasonic welding or crimping. The bonding wire has the advantages of high flexibility and reliable connection, and is suitable for complex or precise circuit connection.

[0035] In a preferred embodiment, see Figure 2 As shown, the first heat sink 5 is connected to the first surface of the first substrate 3 through a third connection layer 10 , and the second heat sink 6 is connected to the second surface of the second substrate 4 through a fourth connection layer 11 .

[0036] The main function of the third connecting layer 10 and the fourth connecting layer 11 is heat conduction. They can effectively conduct the heat on the first substrate 3 and the second substrate 4 to the first heat sink 5 and the second heat sink 6, and then dissipate the heat to the external environment through the heat dissipation surfaces of the first heat sink 5 and the second heat sink 6.

[0037] The third connection layer 10 and the fourth connection layer 11 can also ensure close contact between the first heat sink 5 and the first substrate 3, and between the second heat sink 6 and the second substrate 4, thereby reducing thermal resistance. Close contact can maximize heat conduction efficiency, thereby more effectively conducting heat from the chip to the heat sink.

[0038] In addition to heat conduction, the third connection layer 10 and the fourth connection layer 11 also provide a certain mechanical support function, which can maintain a stable connection between the first heat sink 5 and the first substrate 3, and between the second heat sink 6 and the second substrate 4, and prevent the connection from loosening or failing due to vibration or temperature changes.

[0039] By optimizing the design and material selection of the third connection layer 10 and the fourth connection layer 11, the heat dissipation efficiency can be significantly improved, so that the power module can operate stably at a higher temperature and extend the service life. The third connection layer 10 and the fourth connection layer 11 can effectively reduce the thermal resistance, so that the heat can be transferred to the first heat sink 5 and the second heat sink 6 more quickly, thereby improving the overall heat dissipation performance. The third connection layer 10 and the fourth connection layer 11 also provide additional mechanical support, which helps to maintain a stable connection between the heat sink and the substrate, and improve the reliability and durability of the power module.

[0040] Furthermore, the third connection layer 10 and the fourth connection layer 11 are independently solder, silver sintered layer or copper sintered layer.

[0041] Solder is a widely used connection material, usually containing elements such as tin, lead, silver, and copper. It can melt at high temperatures to form a liquid alloy that fills the connection gap, and solidifies after cooling to form a strong connection. Solder connection has the advantages of simple process, low cost, high connection strength, and good electrical and thermal conductivity. However, some solders may contain elements that are harmful to the human body and may degrade in certain high temperature or corrosive environments.

[0042] Silver sintered layer is formed by mixing silver powder with organic binder and then heating to high temperature to melt and sinter the silver powder together. It has high thermal conductivity, low resistivity, good corrosion resistance and mechanical strength. Silver sintered layer connection has the advantages of good high temperature stability and high connection strength, but the cost is relatively high and requires special sintering equipment and process.

[0043] Copper sintering is similar to silver sintering, but copper powder is used instead of silver powder. Copper has high thermal conductivity, good electrical conductivity, and mechanical strength at a relatively low cost. Copper sintering connections have the advantages of low cost and high thermal conductivity, but may require sintering at high temperatures and may require additional corrosion protection in some applications.

[0044] Whether it is solder, silver sintering layer or copper sintering layer, they all have high thermal conductivity, can efficiently transfer heat and improve heat dissipation performance. The connection layer formed by these materials has good mechanical strength and durability, which can ensure a stable connection between the heat sink and the substrate.

[0045] These connecting layer materials can be processed by different process methods (such as welding, sintering, etc.) to meet different production requirements.

[0046] In a preferred embodiment, the first chip 1 and the second chip 2 are independently silicon-based IGBT chips, silicon-based FRD chips or silicon carbide-based MOSFET chips.

[0047] In a preferred embodiment, both the first substrate 3 and the second substrate 4 are three-layer composite structures, and the first substrate 3 or the second substrate 4 includes a conductive metal layer located at the upper and lower parts and an insulating ceramic layer in the middle of the interlayer. The conductive metal layer is made of copper; the insulating ceramic layer is made of alumina ceramic, aluminum nitride ceramic or silicon nitride ceramic.

[0048] This arrangement combines the high conductivity of metals with the high insulation of ceramics, providing the following advantages for power modules: 1) High thermal conductivity: Conductive metal layers (such as copper or aluminum) have high thermal conductivity and can effectively conduct the heat generated on the chip to the heat sink.

[0049] 2) High insulation: The insulating ceramic layer (such as alumina, silicon nitride or aluminum nitride) has high insulation resistance and breakdown voltage, which can ensure electrical isolation inside the substrate and prevent safety issues such as short circuits and electric shocks.

[0050] 3) Good mechanical properties: The three-layer composite structure combines the strength of metal and the hardness of ceramic, allowing the substrate to withstand large mechanical stress and temperature changes.

[0051] It should be noted that there are usually circuit etching patterns on the second surface of the first substrate 3 in contact with the first connection layer 7 and the first surface of the second substrate 4 in contact with the second connection layer 8 to achieve electrical interconnection.

[0052] In a preferred embodiment, see Figure 2 As shown, the double-sided direct cooling power module also includes a pad 12, and the pad 12 includes a fifth connection layer, a conductive layer and a sixth connection layer. The fifth connection layer is connected to the second surface of the first substrate 3, and the sixth connection layer is connected to the first surface of the second substrate. The conductive layer is connected between the fifth connection layer and the sixth connection layer. In this way, the pad 12 can provide electrical connection and heat conduction functions while connecting the two substrates 3 and 4. Specifically: Fifth and sixth connection layers: These connection layers are usually solder or silver sintering materials.

[0053] The conductive layer is made of copper or molybdenum-copper alloy, and is located between the fifth connection layer and the sixth connection layer, and is usually made of metal or alloy material. The conductive layer provides an electrical connection function to ensure safe and stable operation of the power module.

[0054] In a preferred embodiment, see Figure 1 and Figure 2 As shown, the double-sided direct cooling power module further includes pins 13 , and the pins 13 are connected to the first substrate 3 and / or the second substrate 4 .

[0055] The pin 13 is a bridge between the power module and the external circuit, and its design is crucial to the electrical performance and reliability of the module. In a double-sided direct cooling power module, the pin 13 can be connected to the first substrate 3 and / or the second substrate 4 to transmit the electrical signal inside the module to the external circuit. The selection and layout of the pin 13 should be designed and optimized according to the specific application requirements to ensure good electrical connection and heat dissipation performance.

[0056] In a preferred embodiment, see Figure 2As shown, the first heat sink 5 and the second heat sink 6 include a plurality of parallel cooling medium flow channels, which improve the temperature difference between different areas of the double-sided direct cooling power module during operation and improve the efficiency and reliability of the overall system.

[0057] In a preferred embodiment, see Figure 3 As shown, the number of double-sided direct cooling power modules is three. Accordingly, the three first heat sinks 5 and the three second heat sinks 6 in the three double-sided direct cooling power modules are connected in parallel in the cooling flow path. During operation, the cooling medium flows through the three double-sided direct cooling power modules in parallel to form a parallel cooling system. Figure 4 Compared with the traditional series cooling system, the parallel cooling system is conducive to improving the temperature difference between the three double-sided direct cooling power modules during operation, thereby improving the efficiency and reliability of the overall system.

[0058] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or change made by a person skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. A double-sided direct cooling power module, characterized in that: The invention comprises a first chip (1), a second chip (2), a first heat sink (5), a second heat sink (6), and a first substrate (3) and a second substrate (4) arranged opposite to each other, wherein the first chip (1) is electrically connected to the second surface of the first substrate (3), and the first surface of the first substrate (3) is connected to the first heat sink (5); the second chip (2) is electrically connected to the first surface of the second substrate (4), and the second surface of the second substrate (4) is connected to the second heat sink (6).

2. The double-sided direct cooling power module according to claim 1, characterized in that: The first chip (1) is connected to the second surface of the first substrate (3) via a first connection layer (7) and / or a binding wire (9), and the second chip (2) is connected to the first surface of the second substrate (4) via a second connection layer (8) and / or a binding wire (9).

3. The double-sided direct cooling power module according to claim 2, characterized in that: The first connecting layer (7) and the second connecting layer (8) are independently solder or silver sintering layer; The material of the binding wire (9) is aluminum or copper.

4. The double-sided direct cooling power module according to claim 1, characterized in that: The first heat sink (5) is connected to the first surface of the first substrate (3) via a third connection layer (10), and the second heat sink (6) is connected to the second surface of the second substrate (4) via a fourth connection layer (11); The third connection layer (10) and the fourth connection layer (11) are independently solder, a silver sintered layer or a copper sintered layer.

5. The double-sided direct cooling power module according to claim 1, characterized in that: The first chip (1) and the second chip (2) are independently silicon-based IGBT chips, silicon-based FRD chips or silicon carbide-based MOSFET chips.

6. The double-sided direct cooling power module according to claim 1, characterized in that: The first substrate (3) and the second substrate (4) are both three-layer composite structures, wherein the first substrate (1) or the second substrate (2) comprises a conductive metal layer located at the upper and lower parts and an insulating ceramic layer located in the middle of the interlayer; The material of the conductive metal layer is copper; the material of the insulating ceramic layer is alumina ceramic, aluminum nitride ceramic or silicon nitride ceramic.

7. The double-sided direct cooling power module according to claim 1, characterized in that: It also comprises a cushion block (12), the cushion block (12) comprising a fifth connection layer, a conductive layer and a sixth connection layer, the fifth connection layer being connected to the second surface of the first substrate (3), the sixth connection layer being connected to the first surface of the second substrate (4), and the conductive layer being connected between the fifth connection layer and the sixth connection layer; The material of the fifth connection layer and the sixth connection layer is solder or silver sintered layer; the material of the conductive layer is copper or molybdenum-copper alloy.

8. The double-sided direct cooling power module according to claim 1, characterized in that: It also includes a pin (13), wherein the pin (13) is connected to the first substrate (3) and / or the second substrate (4).

9. The double-sided direct cooling power module according to claim 1, characterized in that: The first radiator (5) and the second radiator (6) comprise a plurality of cooling medium flow channels connected in parallel.

10. The double-sided direct cooling power module according to claim 1, characterized in that: A plurality of first radiators (5) and a plurality of second radiators (6) are connected in parallel in the cooling flow path.

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