Power Devices

Abstract

The present invention provides a power device, the power device comprising: a first bridge arm structure, comprising a first liner, a second liner and a first chip, the second liner is arranged on the upper surface of the first liner, the drain of the first chip is conductively connected to the upper surface of the first liner, and the source of the first chip is conductively connected to the upper surface of the second liner; a terminal assembly, comprising a first power terminal and a second power terminal, the first power terminal is electrically connected to the upper surface of the first liner, the second power terminal is electrically connected to the upper surface of the second liner, and the first power terminal and the second power terminal are located on the same side of the first liner. The technical solution provided by the present application can solve the problems of poor heat dissipation and low switching speed of power devices in related technologies.

Description

Technical Field

[0001] The present invention relates to the technical field of power devices, and in particular to a power device. Background Art

[0002] Power devices are devices used in the field of power electronics to control and convert electrical energy. They are used to perform power conversion functions such as rectification, inversion, chopping, and frequency conversion. They are widely used in power management, motor drive, solar inverter, power system, energy storage and other fields.

[0003] In the related art, the power device includes a copper-clad ceramic substrate, a power chip, and a power terminal, and the power terminal and the power chip are all arranged on the copper-clad ceramic substrate. The upper copper layer of the copper-clad ceramic substrate can only provide electrical connection to the drain electrode at the bottom of the power chip. In order to provide electrical connection to the gate and source electrodes on the front of the power chip, the current practice is to divide the upper copper layer of the copper-clad ceramic substrate to form multiple patterns, and use different patterns as the connection parts of the gate and source of the power chip, and then use bonding wires to connect the gate and source electrodes on the front of the chip to these patterns.

[0004] However, with the above configuration, the upper copper layer of the copper-clad ceramic substrate and the heat dissipation area of ​​the power chip will be reduced, thereby increasing the thermal resistance from the power chip to the device housing. On the other hand, since the source of the chip needs to be connected to the source area of ​​the upper copper layer through a longer bonding wire, the parasitic inductance of the current loop of the device will also increase, thereby affecting the switching speed of the device. Summary of the invention

[0005] The present invention provides a power device to solve the problems of poor heat dissipation and low switching speed of the power device in the related art.

[0006] According to one aspect of the present invention, a power device is provided, which includes: a first bridge arm structure, including a first substrate, a second substrate and a first chip, the second substrate is arranged on the upper surface of the first substrate, the drain of the first chip is conductively connected to the upper surface of the first substrate, and the source of the first chip is conductively connected to the upper surface of the second substrate; a terminal assembly, including a first power terminal and a second power terminal, the first power terminal is electrically connected to the upper surface of the first substrate, the second power terminal is electrically connected to the upper surface of the second substrate, and the first power terminal and the second power terminal are located on the same side of the first substrate.

[0007] Furthermore, the second liner includes a first connecting plate and a first outer convex plate connected to the first connecting plate, the first outer convex plate is located on a side of the first connecting plate away from the first chip, the drain of the first chip is conductively connected to the first connecting plate, the second power terminal is arranged on the first outer convex plate, and the first power terminal is located on a side of the first connecting plate away from the first chip.

[0008] Furthermore, the first bridge arm structure also includes a first PCB board, the terminal assembly also includes a driving terminal, the upper surface of the first PCB board is conductively connected to the gate and auxiliary source of the first chip and the driving terminal respectively, and a resistor is arranged on the upper surface of the first PCB board.

[0009] Furthermore, the resistor includes a gate resistor and an auxiliary source resistor, the driving terminal includes a gate terminal and an auxiliary source terminal, and the gate terminal, the gate resistor, the first chip, the auxiliary source resistor and the auxiliary source terminal are connected in series in sequence.

[0010] Furthermore, the first bridge arm structure also includes a first driving liner, the gate terminal and the auxiliary source terminal are both arranged on the first driving liner, and the upper surface of the first driving liner is electrically connected to the upper surface of the first PCB board.

[0011] Further, the first PCB board is located between the first driving lining board and the first lining board, and the second lining board is located on a side of the first lining board away from the first PCB board.

[0012] Furthermore, the power device further includes a base plate, the first liner plate is arranged on the base plate, and the first PCB board is arranged on the first liner plate or the base plate.

[0013] Furthermore, there are multiple first chips and multiple resistors, and the multiple resistors are all arranged on the upper surface of the first PCB board. The multiple first chips and the multiple resistors are electrically connected in a one-to-one correspondence.

[0014] Further, a plurality of first chips are arranged on the first substrate at intervals along the width direction of the first substrate; and / or a plurality of resistors are arranged on the first PCB at intervals along the width direction of the first substrate.

[0015] Furthermore, the first bridge arm structure also includes a power element, which is arranged on the upper surface of the first liner, the upper surface of the power element is conductively connected to the second liner, and the lower surface of the power device is conductively connected to the upper surface of the first liner.

[0016] Furthermore, the power element is a power chip or a diode.

[0017] Furthermore, the first bridge arm structure also includes a conductive connector, which has a first connecting part, a second connecting part and a third connecting part. The first connecting part is conductively connected to the source of the first chip, the second connecting part is electrically connected to the upper surface of the power element, and the third connecting part is electrically connected to the upper surface of the second liner.

[0018] Furthermore, the power device also includes a second bridge arm structure, the second bridge arm structure includes a third liner, a fourth liner and a second chip, the fourth liner is arranged on the upper surface of the third liner, the drain of the second chip is conductively connected to the upper surface of the third liner, the source of the second chip is conductively connected to the upper surface of the fourth liner, the upper surface of the fourth liner is conductively connected to the upper surface of the first liner, the terminal assembly also includes a third power terminal and a second drive terminal, the third power terminal is electrically connected to the upper surface of the third liner, and the second drive terminal is electrically connected to the upper surface of the second chip.

[0019] Furthermore, the first bridge arm structure and the second bridge arm structure are arranged at intervals, the fourth liner is located between the third power terminal and the second chip, and the third power terminal is located on a side of the third liner close to the first liner.

[0020] Furthermore, the fourth substrate includes a second connecting plate and a second convex plate connected to the second connecting plate, the second connecting plate is electrically connected to the source of the second chip, the upper surface of the second convex plate is electrically connected to the upper surface of the first substrate, and the third power terminal and the second convex plate are located on the same side of the second connecting plate.

[0021] By applying the technical solution of the present invention, the power device includes a first bridge arm structure and a terminal assembly, and the current flows through the first power terminal, the upper surface of the first substrate, the drain of the first chip, the source of the first chip, the upper surface of the second substrate and the second power terminal. Since the second substrate is arranged on the upper surface of the first substrate, when the current flows through the first substrate and the second substrate through the first chip, the current flows in opposite directions in the first substrate and the second substrate. Since the first power terminal and the second power terminal are located on the same side of the first substrate, the current flows into the first bridge arm structure through the first power terminal and flows out of the first bridge arm structure through the second power terminal. The current flows in opposite directions in the first power terminal and the second power terminal, and thus a folded current loop can be formed from the current inflow direction to the current outflow direction, thereby generating a higher mutual inductance, so that the parasitic inductance generated by the two currents flowing in opposite directions cancel each other out, and the parasitic inductance of the current loop can be reduced relative to a longer bonding wire, thereby improving the switching speed of the device. Furthermore, since the current of the source of the first chip forms a loop by providing the second liner, the upper copper layer of the first liner where the first chip is located does not need to be divided into patterns, thereby providing a larger heat dissipation space for the first chip and reducing the thermal resistance of the chip shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1A schematic diagram of the structure of a power device provided in an embodiment of the present invention is shown;

[0024] Figure 2 Shows Figure 1 A partial enlarged view of the middle A;

[0025] Figure 3 Shows Figure 1 A partial enlarged view of point B in the middle;

[0026] Figure 4 An exploded view of a power device provided according to an embodiment of the present invention is shown;

[0027] Figure 5 Shows Figure 4 A partial enlarged view of point C in the middle;

[0028] Figure 6 Shows Figure 4 A partial enlarged view of point D in the middle;

[0029] Figure 7 Another exploded diagram of a power device provided according to an embodiment of the present invention is shown;

[0030] Figure 8 Shows Figure 7 A partial enlarged view of point E in the middle;

[0031] Fig. 9 Shows Figure 7 A partial enlarged view of point F in the middle;

[0032] Fig.10 A packaging diagram of a power device provided according to an embodiment of the present invention is shown.

[0033] The above drawings include the following reference numerals:

[0034] 10. Bottom plate;

[0035] 20. First bridge arm structure; 21. First lining plate; 22. Second lining plate; 221. First connecting plate; 222. First outer convex plate; 23. First chip; 24. First PCB board; 241. Resistor; 242. Gate resistor; 243. Auxiliary source resistor; 25. First driving lining plate; 26. Power element; 27. Conductive connector;

[0036] 30. Terminal assembly; 31. First power terminal; 32. Second power terminal; 33. First drive terminal; 331. Gate terminal; 332. Auxiliary source terminal; 34. Third power terminal; 35. Second drive terminal;

[0037] 40. The second bridge arm structure; 41. The third lining plate; 42. The fourth lining plate; 421. The second connecting plate; 422. The second outer convex plate; 43. The second chip; 44. The second PCB board; 45. The second driving lining plate. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] like Figures 1 to 10 As shown, an embodiment of the present invention provides a power device, which includes a base plate 10, a first bridge arm structure 20, and a terminal assembly 30. The first bridge arm structure 20 includes a first liner 21, a second liner 22, and a first chip 23. The first liner 21 is arranged on the base plate 10, and the second liner 22 is arranged on the upper surface of the first liner 21. The drain of the first chip 23 is conductively connected to the upper surface of the first liner 21, and the source of the first chip 23 is conductively connected to the upper surface of the second liner 22; the terminal assembly 30 includes a first power terminal 31 and a second power terminal 32. The first power terminal 31 is electrically connected to the upper surface of the first liner 21, and the second power terminal 32 is electrically connected to the upper surface of the second liner 22. The first power terminal 31 and the second power terminal 32 are located on the same side of the first liner 21.

[0040] The technical solution of the present invention is applied, and the power device includes a first bridge arm structure 20 and a terminal assembly 30. The current flows through the first power terminal 31, the upper surface of the first substrate 21, the drain of the first chip 23, the source of the first chip 23, the upper surface of the second substrate 22, and the second power terminal 32. Since the second substrate 22 is arranged on the upper surface of the first substrate 21, when the current flows through the first substrate 21 and flows through the first chip 23 and the second substrate 22, the current flows in opposite directions in the first substrate 21 and the second substrate 22. Since the first power terminal 31 and the second The power terminal 32 is located on the same side of the first liner 21. The current flows into the first bridge arm structure 20 through the first power terminal 31 and flows out of the first bridge arm structure 20 through the second power terminal 32. The current flows in opposite directions in the first power terminal 31 and the second power terminal 32, thereby forming a folded current loop from the current inflow direction to the current outflow direction, thereby generating a higher mutual inductance, so that the parasitic inductance generated by the two currents flowing in opposite directions cancel each other out. Compared with a longer bonding wire, the parasitic inductance of the current loop can be reduced, thereby improving the switching speed of the device. In addition, since the current of the source of the first chip 23 forms a loop by setting the second liner 22, the upper copper layer of the first liner 21 where the first chip 23 is located does not need to be divided into patterns, thereby providing a larger heat dissipation space for the first chip 23. Reduce the thermal resistance of the chip shell.

[0041] The distance between the metal layer of the first liner 21 and the metal layer of the second liner 22 is between 0.25 mm and 3 mm, that is, the distance between the current of the first liner 21 and the current of the second liner 22 is between 0.25 mm and 3 mm, so as to generate higher mutual inductance and reduce parasitic inductance.

[0042] The first liner 21 and the second liner 22 are both copper-clad ceramic substrates, which are three-layer structures, with the upper and lower layers being conductor layers and the middle layer being a ceramic substrate. The upper conductor layer is a conductive layer, forming a topological structure of the circuit. The ceramic substrate of the middle layer plays an insulating and heat-conducting role. The lower copper foil is generally connected to the base plate 10 through a thermal interface material, which plays a heat-conducting role.

[0043] The ceramic substrate of the middle layer can generally be made of ceramic materials such as alumina, aluminum nitride, alumina doped with zirconium oxide, and silicon nitride. Alumina has excellent mechanical strength and chemical corrosion resistance, and is suitable for applications with high durability requirements. Zirconia is known for its outstanding toughness and high temperature resistance, and performs well in high temperature and high stress environments. Aluminum nitride has high thermal conductivity and low expansion coefficient, can effectively dissipate heat, and is suitable for high-power electronic devices. Silicon carbide not only has high hardness and high wear resistance, but also can remain stable at extremely high temperatures, making it very popular in high-temperature electronic devices and high-frequency applications. The diversity and excellent properties of these ceramic materials provide a wide range of choices and significant performance improvements for the design and application of silicon carbide devices.

[0044] The copper-clad ceramic structure described above can be made in the following ways:

[0045] DBC (Direct Bonded Copper): Directly sintering copper foil to Al at high temperature through hot melt bonding. 2 O 3 The composite substrate is made of AlN ceramic surface. Thanks to the high eutectic bonding strength between copper foil and ceramic, the copper thickness of DBC substrate can generally be 100μm-600μm. At the same time, ceramic and copper have good thermal conductivity, and the thermal stability of DBC substrate is also good.

[0046] DPC (Direct Plating Copper) is a ceramic circuit processing technology developed on the basis of ceramic thin film processing. Ceramic is used as the circuit substrate, a metal layer is composited on the surface of the substrate by sputtering, and the circuit is formed by electroplating and photolithography.

[0047] AMB (Active Metal Brazing): AMB is developed based on DBC technology. At high temperature, AgCu solder containing active elements Ti and Zr wets and reacts at the interface between ceramic and metal, thereby achieving heterogeneous bonding between ceramic and metal.

[0048] like Figure 5 and Figure 7 As shown, the second liner 22 includes a first connection plate 221 and a first convex plate 222 connected to the first connection plate 221, the first convex plate 222 is located on the side of the first connection plate 221 away from the first chip 23, the drain of the first chip 23 is conductively connected to the first connection plate 221, the second power terminal 32 is arranged on the first convex plate 222, and the first power terminal 31 is located on the side of the first connection plate 221 away from the first chip 23. The second liner 22 with the above structure can use the first convex plate 222 to set the first power terminal 31, and make the first power terminal 31 and the first convex plate 222 located on the same side, which is conducive to reducing the space occupied by the second liner 22, and when the current flows through the first power terminal 31 and the second power terminal 32 and forms an opposite current flow direction, the upper surface of the first liner 21 has a larger heat dissipation space.

[0049] In this embodiment, there are two connection points between the first power terminal 31 and the first lining plate 21, and there are two first outer convex plates 222. The two first outer convex plates 222 are spaced apart along the width direction of the base plate 10, so that there are two connection points between the second power terminal 32 and the second lining plate 22, and the two connection points between the first power terminal 31 and the first lining plate 21 are located between the two first outer convex plates 222.

[0050] like Figure 1 and Figure 2 As shown, the first bridge arm structure 20 further includes a first PCB board 24, the terminal assembly 30 further includes a first driving terminal 33, the upper surface of the first PCB board 24 is respectively conductively connected to the gate and auxiliary source of the first chip 23 and the first driving terminal 33, and a resistor 241 is disposed on the upper surface of the first PCB board 24. By adopting the above-mentioned first PCB board 24, the internal circuit of the first PCB board 24 can be utilized to make the first driving terminal 33 form an electrical connection relationship with the gate and auxiliary source of different first chips 23.

[0051] Among them, compared with the method of etching the upper copper layer of the first liner 21 to connect the gate and auxiliary source of different first chips 23 to the first driving terminal 33 respectively, the use of the first PCB board 24 can reduce the space occupied by the upper copper layer of the first liner 21, increase the area of ​​the upper copper layer of the first liner 21, and thereby make the area of ​​the first liner 21 for heat dissipation of the first chip 23 larger.

[0052] like Figure 1 and Figure 2 As shown, the resistor 241 includes a gate resistor 242 and an auxiliary source resistor 243, the first driving terminal 33 includes a gate terminal 331 and an auxiliary source terminal 332, and the gate terminal 331, the gate resistor 242, the first chip 23, the auxiliary source resistor 243 and the auxiliary source terminal 332 are sequentially connected in series. With the above structure, the gate resistor 242 and the auxiliary source resistor 243 can be used to form a suitable driving current, so that the first chip 23 can work normally.

[0053] In this embodiment, the driving current flows in from the gate terminal 331, flows through the first PCB board 24, flows through the gate resistor 242 through the internal circuit of the first PCB board 24, flows to the gate of the first chip 23 through the internal circuit of the first PCB board 24, and flows out from the auxiliary source of the first chip 23, flows to the auxiliary source resistor 243 through the internal circuit of the first PCB board 24, and flows out from the auxiliary source terminal 332 through the internal circuit of the first PCB board 24.

[0054] like Figure 1As shown, the first bridge arm structure 20 also includes a first driving liner 25, and the gate terminal 331 and the auxiliary source terminal 332 are both arranged on the first driving liner 25, and the upper surface of the first driving liner 25 is electrically connected to the upper surface of the first PCB board 24. With the above structure, by installing the gate terminal 331 and the auxiliary source terminal 332 on the first driving liner 25, it is possible to avoid installing the gate terminal 331 and the auxiliary source terminal 332 on the first liner 21, avoid pattern division of the upper copper layer of the first liner 21, thereby increasing the area of ​​the upper copper layer of the first liner 21, reducing the space occupied by the upper copper layer of the first liner 21, and making the area of ​​the first liner 21 for heat dissipation of the first chip 23 larger.

[0055] In this embodiment, the first driving lining plate 25 is disposed on the base plate 10 .

[0056] Among them, the auxiliary source is different from the source. The source is an electrode inside the first chip 23, which is responsible for conducting current in the power circuit. The auxiliary source is a special connection technology that provides an additional external connection point for the gate drive circuit. The main purpose of the auxiliary source is to reduce the impact of the source inductance on the switching performance. In the traditional three-pin package, the gate drive circuit and the power circuit share the same source pin, which will cause the source inductance to produce a voltage drop during high-speed switching, affecting the gate voltage, thereby affecting the switching speed and efficiency. By using the auxiliary source, the gate drive circuit can be independent of the power circuit and connected to the source of the device through a dedicated pin (auxiliary source). In this way, even if the current in the power circuit changes, the gate drive circuit will not be affected by the voltage drop caused by the source inductance, thereby achieving faster switching speed and lower switching loss.

[0057] like Figure 1 As shown, the first PCB board 24 is located between the first driving liner 25 and the first liner 21, and the second liner 22 is located on the side of the first liner 21 away from the first PCB board 24. The above layout can make the layout of the first bridge arm structure 20 more reasonable, reduce the space occupied by the first bridge arm structure 20, improve space utilization, and facilitate the arrangement of electrical connectors for electrical connection.

[0058] Specifically, the electrical connector may be a bonding wire, or a bonding copper tape or other connectors that can achieve electrical connection.

[0059] In this embodiment, the first chip 23 is located between the first PCB board 24 and the first liner board 21 .

[0060] Among them, the first driving liner 25 and the first PCB board are arranged on the side close to the auxiliary source and gate of the first chip 23, which is conducive to the arrangement of the driving circuit. The second liner 22 is arranged on the side close to the source of the first chip 23, which is conducive to the arrangement of the power circuit. At the same time, the gate terminal 331 and the auxiliary source terminal 332, the first power terminal 31 and the second power terminal are arranged at both ends of the first bridge arm structure 20, which is conducive to reasonable layout and elimination of parasitic inductance of the circuit.

[0061] like Figure 1 As shown, the first PCB board 24 is arranged on the first liner board 21 or the bottom board 10. The above arrangement has the advantage of being easy to process.

[0062] In this embodiment, the first PCB board 24 is disposed on the first liner board 21 .

[0063] like Figure 1 and Figure 4 As shown, there are multiple first chips 23 and multiple resistors 241, and multiple resistors 241 are arranged on the upper surface of the first PCB board 24. Multiple first chips 23 and multiple resistors 241 are electrically connected in a one-to-one correspondence. Using multiple first chips 23, the flow capacity of the power device during operation can be enhanced to withstand a larger current. By having the resistors 241 correspond to the first chips 23 one by one, a drive circuit can be formed for each first chip 23, so that each first chip 23 works normally.

[0064] The plurality of first chips 23 form a parallel structure in the power circuit, and the sum of the currents of the plurality of first chips 23 is the current of the power circuit of the first bridge arm structure 20 .

[0065] like Figure 4 As shown, a plurality of first chips 23 are arranged on the first liner 21 at intervals along the width direction of the first liner 21, and a plurality of resistors 241 are arranged on the first PCB board 24 at intervals along the width direction of the first liner 21. With the above layout, the space in the width direction of the base plate 10 can be fully utilized, thereby improving the space utilization rate.

[0066] like Figure 2 As shown, the first bridge arm structure 20 further includes a power element 26, which is disposed on the upper surface of the first liner 21, the upper surface of the power element 26 is conductively connected to the second liner 22, and the lower surface of the power element is conductively connected to the upper surface of the first liner 21. The power element 26 can improve the performance of the first bridge arm structure 20, so that the power element has higher reliability and adaptability.

[0067] The power element 26 may be a power chip, which can be connected in parallel with the original first chip 23 to improve the flow capacity of the first bridge arm structure 20 and the performance of the power device to improve its adaptability.

[0068] In other embodiments, the power element 26 may be a diode. The diode can withstand reverse current, thereby preventing current from flowing through the first chip 23, thereby protecting the first chip 23 and extending the service life of the first chip 23.

[0069] Specifically, when a reverse voltage is added between the first power terminal 31 and the second power terminal 32, since the first chip 23 cannot be turned on, but the first chip 23 needs to withstand the potential difference, after the diode is provided, the current can be directly turned on through the second power terminal 32, the second substrate 22, the diode, the first substrate 21 and the first power terminal 31 in sequence, and avoid flowing through the first chip 23, thereby preventing the first chip 23 from being subjected to the potential difference, thereby protecting the first chip 23.

[0070] like Figure 2 As shown, the first bridge arm structure 20 further includes a conductive connector 27, which has a first connection portion, a second connection portion and a third connection portion, wherein the first connection portion is conductively connected to the source of the first chip 23, the second connection portion is electrically connected to the upper surface of the power element 26, and the third connection portion is electrically connected to the upper surface of the second liner 22. By adopting the above-mentioned conductive connector 27, the conduction between the first chip 23 and the second liner 22 and the conduction between the power element 26 and the second liner 22 can be directly achieved, which has the advantages of simple structure and convenient connection compared to the method of adopting two conductive connectors to achieve conduction respectively.

[0071] In this embodiment, the conductive connection member 27 is a bonding wire.

[0072] like Figure 1 and Figure 4 As shown, the power device further includes a second bridge arm structure 40, the second bridge arm structure 40 includes a third liner 41, a fourth liner 42 and a second chip 43, the third liner 41 is arranged on the bottom plate 10, the fourth liner 42 is arranged on the upper surface of the third liner 41, the drain of the second chip 43 is conductively connected to the upper surface of the third liner 41, the source of the second chip 43 is conductively connected to the upper surface of the fourth liner 42, the upper surface of the fourth liner 42 is conductively connected to the upper surface of the first liner 21, the terminal assembly 30 further includes a third power terminal 34 and a second drive terminal 35, the third power terminal 34 is electrically connected to the upper surface of the third liner 41, and the second drive terminal 35 is electrically connected to the upper surface of the second chip 43. The above-mentioned second bridge arm structure 40 can be used in conjunction with the first bridge arm structure 20 to form a half-bridge topology circuit to achieve power amplification and inversion functions.

[0073] Among them, in a half-bridge circuit, the two bridge arms are usually not turned on at the same time, because this will cause a short circuit. The working principle of the half-bridge circuit is to alternately turn on the two bridge arms to generate the required output voltage and current waveforms. For example, in a half-bridge inverter, when one bridge arm is turned on, the other bridge arm should be in the off state to avoid current flowing directly back from the power supply and causing a short circuit.

[0074] In this embodiment, the first power terminal 31 is an AC terminal, the second power terminal 32 is a DC-terminal, and the third power terminal 34 is a DC+terminal.

[0075] Specifically, when the power circuit of the second bridge arm structure 40 is turned on, current flows in from the third power terminal 34 , flows to the drain of the second chip 43 through the third substrate 41 , flows out from the source of the second chip 43 , flows to the fourth substrate 42 , and then flows out through the second substrate 22 and the first power terminal 31 .

[0076] Among them, the first liner 21 and the third liner 41 are both rectangular structures. The upper copper layers of the first liner 21 and the third liner 41 are both rectangular structures. Of course, in other embodiments not shown in the figures, the copper-clad ceramic substrate may not be arranged in a rectangular structure, but may be a quadrilateral, a pentagon, a hexagon or a circle. At the same time, the upper copper layer is not limited to a rectangular structure, but may be a quadrilateral, a pentagon, a hexagon or a circle.

[0077] The first lining plate 21 and the third lining plate 41 with a rectangular structure have wide applicability in practical applications. The rectangular substrate is not only simple to manufacture, but also can provide good mechanical strength and stability in most cases. The rectangular substrate is also common in circuit board design, and is easy to integrate and connect with other components.

[0078] The upper copper layer is also designed as a rectangular structure, which is also convenient in process manufacturing. In addition, the design of the rectangular upper copper layer can better match the rectangular substrate, making the overall structure more compact and reasonable.

[0079] However, the present invention is not limited to the rectangular structure design in the above embodiment. Different shapes can be adopted according to the needs of practical applications. For example, it can be designed into a quadrilateral, pentagonal, hexagonal or even circular structure. Quadrilateral substrates can provide greater design flexibility and make circuit design more diverse; pentagonal and hexagonal substrates can provide unique mechanical and electrical properties in specific application scenarios; circular substrates can be considered for application in certain specific scenarios.

[0080] Similarly, the upper copper layer is not limited to a rectangular structure and can be designed into a quadrilateral, pentagon, hexagon or circle according to actual needs. The polygonal metal layer design can provide more contact surfaces and increase the stability and reliability of electrical connections; the circular metal layer can be considered for use in certain specific scenarios.

[0081] In practical applications, the specific shape design needs to be comprehensively considered based on many factors. The first is the feasibility of the manufacturing process. Copper-clad ceramic substrates of different shapes will face different technical challenges during the manufacturing process. The second is the requirements for electrical performance. Metal layers of different shapes will affect the electrical characteristics of the circuit. In addition, mechanical strength and stability need to be considered. Substrates of different shapes will exhibit different mechanical properties during use.

[0082] In practical applications, a variety of geometric shapes can be designed according to actual application requirements to achieve the purpose of optimizing electrical performance, mechanical performance and manufacturing cost.

[0083] like Figure 1 As shown, the first bridge arm structure 20 and the second bridge arm structure 40 are arranged at intervals, the fourth liner 42 is located between the third power terminal 34 and the second chip 43 , and the third power terminal 34 is located on a side of the third liner 41 close to the first liner 21 . By adopting the above arrangement, on the one hand, the space in the length direction of the base plate 10 can be fully utilized to improve the space occupancy rate. On the other hand, since the fourth liner 42 is arranged on the upper surface of the third liner 41, when the current flows through the third liner 41 and flows through the fourth liner 42 through the second chip 43, the current flows in opposite directions in the third liner 41 and the fourth liner 42. Since the first power terminal 31 and the third power terminal 34 are located on the same side of the third liner 41, the current flows into the second bridge arm structure 40 through the third power terminal 34 and flows out of the second bridge arm structure 40 through the first power terminal 31. The current flows in opposite directions in the first power terminal 31 and the third power terminal 34, and thus a folded current loop can be formed from the current inflow direction to the current outflow direction, thereby generating a higher mutual inductance, so that the parasitic inductance generated by the two currents flowing in opposite directions cancel each other out. Compared with a longer bonding wire, the parasitic inductance of the current loop can be reduced, thereby improving the switching speed of the device. Furthermore, since the fourth liner 42 is provided to form a loop for the current of the source of the second chip 43, the upper copper layer of the third liner 41 where the second chip 43 is located does not need to be divided into patterns, thereby providing a larger heat dissipation space for the second chip 43. The thermal resistance of the chip shell is reduced.

[0084] Specifically, the first bridge arm structure 20 and the second bridge arm structure 40 are sequentially arranged along the length direction of the bottom plate 10 .

[0085] like Figure 6 and Figure 7As shown, the fourth liner 42 includes a second connection plate 421 and a second convex plate 422 connected to the second connection plate 421, the second connection plate 421 is electrically connected to the source of the second chip 43, the upper surface of the second convex plate 422 is electrically connected to the upper surface of the first liner 21, and the third power terminal 34 and the second convex plate 422 are located on the same side of the second connection plate 421. The fourth liner 42 with the above structure can be connected to the first liner 21 by using the second convex plate 422, and the third power terminal 34 can be located on the side of the second connection plate 421 away from the second chip 43. On the one hand, it is conducive to reducing the space occupied by the fourth liner 42, and after the current flows through the first power terminal 31 and the third power terminal 34 and forms an opposite current flow direction, the upper surface of the third liner 41 has a larger heat dissipation space.

[0086] In this embodiment, there are two connection points between the third power terminal 34 and the third lining plate 41, and there are three second outer protruding plates 422. The three second outer protruding plates 422 are arranged at intervals along the width direction of the base plate 10, and the two connection points between the third power terminal 34 and the third lining plate 41 are respectively located between two adjacent second outer protruding plates 422.

[0087] Except that the structures of the fourth lining plate 42 and the second lining plate 22 are different, the remaining structures of the first bridge arm structure 20 and the remaining structures of the second bridge arm structure 40 are symmetrically arranged on the bottom plate 10 .

[0088] It should be noted that the second bridge arm structure 40 further includes a second PCB board 44, the upper surface of which is respectively conductively connected to the gate and auxiliary source of the second chip 43 and the second driving terminal 35, and a resistor is provided on the upper surface of the second PCB board 44. By adopting the above-mentioned second PCB board 44, the internal circuit of the second PCB board 44 can be utilized to make the second driving terminal 35 electrically connected to the gate and auxiliary source of different second chips 43.

[0089] Among them, compared with the method of etching the upper copper layer of the third liner 41 to connect the gate and auxiliary source of different second chips 43 to the second drive terminal 35 respectively, the use of the second PCB board 44 can reduce the space occupied by the upper copper layer of the third liner 41, increase the area of ​​the upper copper layer of the third liner 41, and thereby make the area of ​​the third liner 41 for heat dissipation of the second chip 43 larger.

[0090] Specifically, the resistors on the second PCB board 44 also include gate resistors and auxiliary source resistors, and the electrical connection structure thereof is the same as the electrical connection structure on the first PCB board 24 .

[0091] In this embodiment, compared with the drive connection method of directly dividing the area on the copper-clad ceramic substrate, the multi-layer circuit structure of the PCB board can improve the flexibility of the drive circuit, save the space of the copper-clad ceramic substrate, and provide a larger heat dissipation space for the power chip, reducing the thermal resistance of the chip shell. Compared with the drive connection PCB board of other devices suspended on the shell, the process is relatively simple, no specially designed shell is required, and the drive connection PCB board and the power chip are directly welded on the copper-clad ceramic substrate.

[0092] In addition, the second bridge arm structure 40 also includes a second driving liner 45, which is arranged on the base plate 10, and the gate terminal and the auxiliary source terminal of the second bridge arm structure 40 are both arranged on the second driving liner 45, and the upper surface of the second driving liner 45 is electrically connected to the upper surface of the second PCB board 44.

[0093] The third liner 41 may also be provided with parallel chips to improve the current carrying capacity of the second bridge arm structure 40 , or a diode may be provided to withstand reverse current to protect the second chip 43 .

[0094] In this embodiment, the ratio of the sum of the areas of the lower surfaces of the first lining plate 21 and the third lining plate 41 to the area of ​​the bottom plate 10 is about 0.55.

[0095] It should be noted that the first chip 23 and the second chip 43 provided in this embodiment are both silicon carbide MOSFET chips.

[0096] The first power terminal 31, the second power terminal 32, the third power terminal 34, and the drive terminals in the terminal assembly 30 can be connected by a sintering process. The first chip 23 and the second chip 43 are connected to the corresponding copper-clad ceramic substrate by a sintering process. The sintering process can be a nano-silver sintering process.

[0097] The nano-silver sintering process is an innovative material connection technology, which is particularly suitable for the manufacture of electronic packaging and high-power devices. This process forms a connection layer with high conductivity and high thermal conductivity by sintering nano-scale silver particles at low temperature, which has significant technical advantages and wide application potential. The nano-silver sintering process has become an important technology in the manufacture of electronic packaging and high-power devices due to its low-temperature sintering, high conductivity, high thermal conductivity, mechanical strength and environmental protection characteristics. It not only improves the performance and reliability of electronic devices, but also provides a green and environmentally friendly solution. The benefits of using the nano-silver sintering process are as follows:

[0098] 1. Low-temperature sintering: A major advantage of the nanosilver sintering process is its low-temperature sintering characteristics. Conventional metal sintering processes usually require high temperatures (over 800°C) to achieve effective sintering, while nanosilver sintering can be completed between 200°C and 300°C. This low-temperature sintering characteristic makes the process particularly suitable for temperature-sensitive electronic components and materials, such as certain semiconductors and organic materials, thereby avoiding thermal damage and material degradation that may be caused by high temperatures.

[0099] 2. High conductivity: The connection layer formed by the nanosilver particles after sintering has excellent conductivity. As a metal, silver has the highest conductivity among all metals. The nanosilver sintering process can achieve close connection between silver particles at a lower temperature, thereby forming a low-resistance connection layer. This can significantly improve the performance and efficiency of electronic devices and circuit boards that require efficient electrical transmission.

[0100] 3. High thermal conductivity: In addition to high electrical conductivity, the nanosilver sintered layer also has high thermal conductivity. This means that it can effectively dissipate heat and avoid failure or performance degradation of electronic devices due to overheating. In high-power devices such as power semiconductors, LEDs, and high-frequency communication equipment, good thermal management is a key factor in ensuring their stability and long life.

[0101] 4. Mechanical strength and stability: The nanosilver sintering process can achieve close bonding of silver particles at a lower temperature, forming a connection layer with high mechanical strength and stability. Compared with traditional welding methods, the nanosilver sintered layer has higher reliability and durability, and can better resist fatigue and damage caused by mechanical stress and thermal cycles.

[0102] 5. Environmentally friendly features: The nanosilver sintering process does not contain lead and meets environmental protection requirements. Traditional soldering processes often use lead-containing solder, which, despite its superior performance, is harmful to the environment and health. Nanosilver sintering provides a green alternative that is in line with the environmental development trend in the future electronic packaging and manufacturing fields.

[0103] 6. Process flexibility: Nanosilver sintering materials are usually in the form of paste, which can be coated and printed by a variety of methods such as screen printing, spraying or dispensing. This flexibility enables the process to adapt to different manufacturing needs and design requirements, providing higher design freedom and manufacturing efficiency.

[0104] The upper package of the base plate 10 is a package shell, and the space between the package shell and the base plate 10 forms a package space, and the first bridge arm structure 20 and the second bridge arm structure 40 are both packaged in the package space. The first power terminal 31, the second power terminal 32, the third power terminal 34, and each drive terminal all pass through the package shell and form an electrical connection with external components.

[0105] Coating the first chip and the second chip with PI coating has many significant benefits in improving the performance, reliability and durability of the chip. The following are several major advantages of using PI coating:

[0106] 1. Excellent thermal stability: Polyimide materials have excellent thermal stability and can maintain their physical and chemical properties in high temperature environments. For chips working under high temperature conditions, PI coating can effectively protect the chip from thermal stress, thereby extending the service life of the chip. PI materials are generally able to withstand high temperatures, which makes it very valuable in high-temperature electronic devices and high-power applications.

[0107] 2. Electrical insulation performance: PI coating has good electrical insulation performance, which can prevent electrical short circuits and leakage inside the chip. Its high insulation ensures the safe operation of the chip in high voltage and high frequency environments, reducing the risk of electrical failure. This is especially important for electronic devices that require high reliability.

[0108] 3. Mechanical strength and flexibility: Polyimide materials have both high mechanical strength and flexibility, and can resist external mechanical stress and impact. The PI coating applied on the chip surface can provide additional protection to prevent the chip from being mechanically damaged during manufacturing, transportation and use. At the same time, the flexibility of the PI coating enables it to adapt to slight deformation and stress changes on the chip surface, maintaining the integrity and effectiveness of the coating.

[0109] 4. Chemical corrosion resistance: PI material has excellent chemical corrosion resistance and can resist erosion by various chemical reagents, solvents and corrosive gases. Coating with PI coating can effectively protect the chip from chemical corrosion, especially in some harsh working environments, such as industrial control, chemical production and environmental monitoring equipment.

[0110] 5. Low dielectric constant: Polyimide has a low dielectric constant, which is an important advantage for high-speed and high-frequency circuits. Low dielectric constant helps reduce loss and delay in signal transmission, improve signal transmission speed and integrity, and thus improve chip performance and efficiency.

[0111] 6. Process compatibility: PI coating can be applied by a variety of process methods, such as spin coating, spray coating and dip coating, and the process is relatively simple and suitable for large-scale production. This process compatibility enables PI coating to be widely used in the manufacture of different types of chips and electronic devices, providing a flexible solution.

[0112] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0113] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0114] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0115] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0116] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0117] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A power device, characterized in that: The power device comprises: A first bridge arm structure (20) comprises a first liner (21), a second liner (22) and a first chip (23), wherein the second liner (22) is arranged on the upper surface of the first liner (21), the drain of the first chip (23) is conductively connected to the upper surface of the first liner (21), and the source of the first chip (23) is conductively connected to the upper surface of the second liner (22); A terminal assembly (30), comprising a first power terminal (31) and a second power terminal (32), wherein the first power terminal (31) is electrically connected to the upper surface of the first liner (21), and the second power terminal (32) is electrically connected to the upper surface of the second liner (22), and the first power terminal (31) and the second power terminal (32) are located on the same side of the first liner (21); The first bridge arm structure (20) further comprises a first PCB board (24); the terminal assembly (30) further comprises a first driving terminal (33); the upper surface of the first PCB board (24) is respectively conductively connected to the gate electrode and the auxiliary source electrode of the first chip (23) and the first driving terminal (33); and a resistor (241) is provided on the upper surface of the first PCB board (24); The resistor (241) comprises a gate resistor (242) and an auxiliary source resistor (243); the first drive terminal (33) comprises a gate terminal (331) and an auxiliary source terminal (332); the gate terminal (331), the gate resistor (242), the first chip (23), the auxiliary source resistor (243) and the auxiliary source terminal (332) are connected in series in sequence.

2. The power device according to claim 1, characterized in that: The second liner (22) comprises a first connecting plate (221) and a first convex plate (222) connected to the first connecting plate (221), the first convex plate (222) being located on a side of the first connecting plate (221) away from the first chip (23), the drain of the first chip (23) being conductively connected to the first connecting plate (221), the second power terminal (32) being arranged on the first convex plate (222), and the first power terminal (31) being located on a side of the first connecting plate (221) away from the first chip (23).

3. The power device according to claim 1, characterized in that: The first bridge arm structure (20) further comprises a first driving liner (25), the gate terminal (331) and the auxiliary source terminal (332) are both arranged on the first driving liner (25), and the upper surface of the first driving liner (25) is electrically connected to the upper surface of the first PCB board (24).

4. The power device according to claim 3, characterized in that: The first PCB board (24) is located between the first driving lining board (25) and the first lining board (21), and the second lining board (22) is located on a side of the first lining board (21) away from the first PCB board (24).

5. The power device according to claim 1, characterized in that: The power device further comprises a base plate (10), the first liner plate (21) being arranged on the base plate (10), and the first PCB board (24) being arranged on the first liner plate (21) or the base plate (10).

6. The power device according to claim 1, characterized in that: There are a plurality of the first chip (23) and the resistor (241), the plurality of resistors (241) are arranged on the upper surface of the first PCB board (24), and the plurality of the first chips (23) and the plurality of resistors (241) are electrically connected in a one-to-one correspondence.

7. The power device according to claim 6, characterized in that: A plurality of the first chips (23) are arranged on the first liner (21) at intervals along the width direction of the first liner (21); and / or a plurality of the resistors (241) are arranged on the first PCB board (24) at intervals along the width direction of the first liner (21).

8. The power device according to claim 1, characterized in that: The first bridge arm structure (20) further comprises a power element (26), wherein the power element (26) is arranged on the upper surface of the first liner (21), the upper surface of the power element (26) is conductively connected to the second liner (22), and the lower surface of the power element is conductively connected to the upper surface of the first liner (21).

9. The power device according to claim 8, characterized in that: The power element (26) is a power chip or a diode.

10. The power device according to claim 8, characterized in that: The first bridge arm structure (20) further comprises a conductive connector (27), the conductive connector (27) comprising a first connecting portion, a second connecting portion and a third connecting portion, the first connecting portion being conductively connected to the source of the first chip (23), the second connecting portion being electrically connected to the upper surface of the power element (26), and the third connecting portion being electrically connected to the upper surface of the second liner (22).

11. The power device according to claim 1, characterized in that: The power device further comprises a second bridge arm structure (40), wherein the second bridge arm structure (40) comprises a third substrate (41), a fourth substrate (42) and a second chip (43), wherein the fourth substrate (42) is arranged on the upper surface of the third substrate (41), the drain of the second chip (43) is conductively connected to the upper surface of the third substrate (41), the source of the second chip (43) is conductively connected to the upper surface of the fourth substrate (42), the upper surface of the fourth substrate (42) is conductively connected to the upper surface of the first substrate (21), and the terminal assembly (30) further comprises a third power terminal (34) and a second drive terminal (35), wherein the third power terminal (34) is electrically connected to the upper surface of the third substrate (41), and the second drive terminal (35) is electrically connected to the upper surface of the second chip (43).

12. The power device according to claim 11, characterized in that: The first bridge arm structure (20) and the second bridge arm structure (40) are arranged at intervals, the fourth liner (42) is located between the third power terminal (34) and the second chip (43), and the third power terminal (34) is located on a side of the third liner (41) close to the first liner (21).

13. The power device according to claim 12, characterized in that: The fourth substrate (42) includes a second connecting plate (421) and a second convex plate (422) connected to the second connecting plate (421), the second connecting plate (421) is electrically connected to the source of the second chip (43), the upper surface of the second convex plate (422) is electrically connected to the upper surface of the first substrate (21), and the third power terminal (34) and the second convex plate (422) are located on the same side of the second connecting plate (421).

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