Longitudinally stacked driving integrated power module packaging structure and packaging method thereof

Abstract

The invention discloses a longitudinally stacked drive integrated power module packaging structure and a packaging method thereof, and the structure comprises a ceramic housing, a heat management subunit which is located in an inner cavity of the ceramic housing and is arranged from bottom to top, a drive circuit subunit which is used as a drive circuit carrier, and a sealing cover plate which is matched with the ceramic housing through a sealing ring. The ceramic shell is of a multi-layer cavity structure, the upper end of the ceramic shell, the sealing ring and the sealing cover plate form sealing, the lower end of the ceramic shell is electrically connected with the heat management subunit to form sealing, a power chip is arranged on the upper surface of the heat management subunit, a driving chip is arranged on the upper surface of the driving circuit subunit, and the power chip is electrically connected with the driving circuit subunit. And the driving circuit subunit is electrically connected with the ceramic shell. According to the invention, high integration level, high reliability and low parasitic inductance are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a longitudinally stacked drive-integrated power module packaging structure and a packaging method thereof. Background Art

[0002] With the demand for miniaturization of microelectronic products in terms of package size, the size of the chip and its package is also required to be continuously reduced, while the packaging density of the devices on the board is continuously improved. Three-dimensional stacking packaging is a high-density packaging technology that has been rapidly developing in recent years. Traditional power devices and drive circuits often use discrete devices for wiring on the board to achieve the corresponding circuit functions. Due to the limitations of packaging reliability and board space size, it is required to integrate power semiconductor chips, driver chips and additional passive devices in one package to form a complete functional device, and to further reduce the overall size. However, the current structural form of power devices cannot meet the needs of miniaturization.

[0003] Therefore, it is urgent to solve the above problems. Summary of the invention

[0004] Purpose of the invention: The first purpose of the present invention is to provide a longitudinally stacked drive-integrated power module packaging structure, which improves the power density per unit packaging area and reduces parasitic inductance.

[0005] A second object of the present invention is to provide a packaging method for a longitudinally stacked driver-integrated power module packaging structure.

[0006] Technical solution: To achieve the above objectives, the present invention discloses a longitudinally stacked integrated drive power module packaging structure including a ceramic shell, a thermal management subunit located in the inner cavity of the ceramic shell and arranged from bottom to top, a driving circuit subunit as a driving circuit carrier, and a sealing cover plate adapted to the ceramic shell through a sealing ring. The ceramic shell is a multi-layer cavity structure, the upper end of the ceramic shell is sealed with the sealing ring and the sealing cover plate, the lower end of the ceramic shell is electrically connected to the thermal management subunit and forms a seal, a power chip is arranged on the upper surface of the thermal management subunit, a power chip is arranged on the upper surface of the driving circuit subunit, and the driving circuit subunit is electrically interconnected with the ceramic shell.

[0007] Optionally, the ceramic shell includes a first chamber, a second chamber, a third chamber and a fourth chamber arranged from top to bottom, a first electrical interface is arranged at the step at the junction of the first chamber and the second chamber, a second electrical interface and an interconnecting metal column are arranged at the step at the junction of the second chamber and the third chamber, an output interface is arranged on the bottom surface of the ceramic shell, and the electrical signals of the first electrical interface and the second electrical interface are output uniformly through the output interface.

[0008] Optionally, the first electrical interface, the second electrical interface and the output interface are conductively connected through interlayer metallization hole filling and wiring, wherein the first electrical interface is a signal interface of a driving circuit sub-unit, which is interconnected with the output interface through metallization hole filling wiring to realize input and output of control signals; the second electrical interface contains a chip mounting position, a signal transmission interface and a high-power current transmission channel, and achieves extremely small on-resistance through low-resistance parallel metallization hole filling; the output interface is arranged around the bottom of the ceramic shell to realize input or output of signals and high-power currents.

[0009] Optionally, mounting holes are arranged around the driving circuit subunit to achieve structural and electrical connection with interconnecting metal columns in the ceramic shell through brazing, and the interconnecting metal columns are in the form of step columns to achieve longitudinal positioning of the driving circuit subunit.

[0010] Optionally, the thermal management subunit includes a first layer for mounting a power chip, a second layer airtightly connected to a fourth chamber of the ceramic shell, and a third layer serving as an electrical output interface and a thermal output channel interface, wherein the first layer, the second layer and the third layer are stacked from top to bottom.

[0011] Optionally, the minimum size of the back step of the thermal management subunit is obtained through thermal simulation calculation, a simulation model of a double-sided boss is built, and corresponding thermal conduction physical parameters are assigned, and heat transfer simulation is performed to obtain the minimum size of the back step.

[0012] Optionally, the ceramic shell and the thermal management subunit are welded at a first welding temperature, the upper surface of the thermal management subunit and the power chip are welded at a second welding temperature, the upper surface of the driving circuit subunit and the driving chip are welded at a third welding temperature, and the driving circuit subunit and the ceramic shell are welded at a fourth welding temperature, wherein the first welding temperature > the second welding temperature > the third welding temperature > the fourth welding temperature, forming multiple temperature gradients.

[0013] Optionally, the driving circuit subunit uses a multi-layer wiring substrate, and the substrate material is aluminum oxide.

[0014] Based on the same inventive concept, the present invention discloses a packaging method for a longitudinally stacked integrated driver power module packaging structure, comprising the following steps:

[0015] S1. Select alumina black porcelain or aluminum nitride ceramic green porcelain tape according to the designed thickness, mark the name of each layer and keep it ready for use;

[0016] S2, using laser ablation process to open holes in each layer of ceramic green tape according to a pre-designed hole pattern;

[0017] S3, using a printing machine to metallize and fill the through holes in step S2;

[0018] S4, using a printer to print surface metallization patterns on the layer where wiring is required;

[0019] S5, performing laser ablation to open a cavity on each layer of the ceramic raw tape according to a pre-designed cavity pattern;

[0020] S6, stacking and laminating the four-layer cavity once respectively to form four semi-finished products;

[0021] S7, printing the four semi-finished products with glue, and laminating them twice within the specified time;

[0022] S8, laminating and raw cutting the semi-finished product of the secondary lamination;

[0023] S9, finally performing cooked porcelain sintering by matching sintering process parameters;

[0024] S10, performing nickel plating and post-nickel heat treatment on the metallized area on the surface of the sintered ceramic component, wherein the ceramic component includes a ceramic housing and a substrate of a drive circuit subunit;

[0025] S11, heat treating and pre-nickel-plating metal parts, the metal parts including sealing rings, interconnecting metal pillars and thermal management subunits;

[0026] S12, placing the ceramic housing, the thermal management subunit, the interconnected metal column, the sealing ring and the silver-copper solder in a graphite mold prefabricated according to the design drawing in sequence, and welding them according to the process temperature curve of silver-copper brazing to form a semi-finished ceramic housing;

[0027] S13, chemically nickel-plating and chemically gold-plating the ceramic housing and the substrate in the driving circuit subunit, and then protecting the thin gold area and electroplating gold to form different thin gold and thick gold areas required by the design, to obtain a finished ceramic housing.

[0028] Optionally, in step S10, after the ceramic part is electrolessly nickel-plated, it is subjected to heat treatment at 350° C. to 400° C. to recrystallize the Ni—P layer, and the heat treatment time is 30 to 40 minutes.

[0029] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: the present invention stacks the power chip and the driver chip vertically, and stacks the driver circuit part with low heat dissipation requirements vertically on the upper part of the power chip, thereby improving the power density per unit packaging area, maximizing the optimization space, and reducing parasitic inductance; the present invention reduces the residual stress of board-level installation by optimizing the design of the heat output channel and reducing the package size; the present invention avoids the problem of electrical performance failure caused by remelting during the packaging process by using multi-temperature gradient solder; thereby achieving high airtightness of the ceramic packaging structure of the present invention, and the outer shell can pass 500 cycles of -65℃~175℃ temperature cycle to meet the high reliability packaging requirements of the power module circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a cross-sectional view of the present invention;

[0031] Figure 2 It is a schematic diagram of the splitting of the present invention;

[0032] Figure 3 It is a structural schematic diagram of the present invention;

[0033] Figure 4 It is a structural schematic diagram of the thermal management subunit in the present invention;

[0034] Figure 5 The structure of the ceramic shell in the present invention is schematically shown in FIG. Figure 1 ;

[0035] Figure 6 The structure of the ceramic shell in the present invention is schematically shown in FIG. Figure 2 .

[0036] In the figure: thermal management subunit 1, first layer 1-1, second layer 1-2, third layer 1-3, ceramic shell 2, first chamber 2-1, second chamber 2-2, third chamber 2-3, fourth chamber 2-4, first electrical interface 2-5, second electrical interface 2-6, interconnecting metal pillars 2-7, output interface 2-8, drive circuit subunit 3, sealing ring 4, sealing cover plate 5. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0038] like Figure 1As shown, a longitudinally stacked integrated drive power module packaging structure of the present invention comprises a thermal management subunit 1, a ceramic shell 2, a drive circuit subunit 3, a sealing ring 4 and a sealing cover plate 5, wherein the thermal management subunit 1 and the drive circuit subunit 3 are both located in the inner cavity of the ceramic shell, and the thermal management subunit 1 and the drive circuit subunit 3 are longitudinally stacked from bottom to top, the ceramic shell 2 is a multi-layer cavity structure, the upper end of the ceramic shell 2 forms a seal with the sealing ring 4 and the sealing cover plate 5, the lower end of the ceramic shell 2 is electrically connected to the thermal management subunit 1 and forms a seal, the upper surface of the thermal management subunit 1 is arranged with a power chip, the upper surface of the drive circuit subunit 3 is arranged with a drive chip, and the drive circuit subunit is electrically interconnected with the ceramic shell. The thermal management subunit 1 is connected to the ceramic shell 2 by brazing to realize the heat extraction of the power chip. The drive circuit subunit 3 realizes electrical signal interconnection through the interconnected metal columns in the ceramic shell 2 and the gold wire bonding method. The sealing ring 4 is placed between the capping layer of the ceramic shell and the sealing cover plate 5 as a transition structure to achieve airtightness. The ceramic shell is sealed with materials such as Ag / Cu, Au / Sn, etc. The size structure of the heat channel at the bottom of the thermal management subunit needs to be designed according to the heat dissipation power requirements of the power chip, which can minimize the mounting area on the board and reduce residual stress. The processing methods of the thermal management subunit structure include but are not limited to one-piece processing or layered welding. Materials include but are not limited to high thermal conductivity conductor materials such as tungsten copper, molybdenum copper, CPC, CMC, etc. The driver subunit adopts a multi-layer board process, and the materials are not limited to PCB, HTCC, film substrates, etc.

[0039] The ceramic shell 2 includes a first chamber 2-1, a second chamber 2-2, a third chamber 2-3 and a fourth chamber 2-4 arranged from top to bottom. A first electrical interface 2-5 is arranged at a step at the junction of the first chamber 2-1 and the second chamber 2-2, a second electrical interface 2-6 and an interconnected metal column 2-7 are arranged at a step at the junction of the second chamber 2-2 and the third chamber 2-3, and an output interface 2-8 is arranged on the bottom surface of the ceramic shell 2. The electrical signals of the first electrical interface 2-5 and the second electrical interface 2-6 are uniformly output through the output interface 2-8. The first electrical interface 2-5, the second electrical interface 2-6 and the output interface 2-8 are connected through interlayer metallization hole filling and wiring, wherein the first electrical interface 2-5 is a signal interface of the driving subunit, and is interconnected with the output interface 2-8 through metallization hole filling wiring to realize the input and output of the control signal; the first electrical interface is arranged on the step surface, not limited to one side or multiple sides. The second electrical interface 2-6 contains a chip mounting position, a signal transmission interface and a high-power current transmission channel, and achieves extremely small on-resistance through low-resistance parallel metallization filling, thereby improving its overcurrent capability. The second electrical interface 2-6 is arranged on the step surface, not limited to one side or multiple sides; the output interface 2-8 is arranged around the bottom of the ceramic shell 2 to realize the input or output of signals and high-power currents.

[0040] The main material of the ceramic shell 2 is alumina ceramic or aluminum nitride ceramic, and the bending strength of the ceramic material is required to be ≥350MPa. The material of the metal pattern and the metal hole on the ceramic part is tungsten metal, wherein the diameter of the metal hole is 100μm to 200μm. The material of the interconnected metal pillars 2-7 includes but is not limited to Kovar alloy or oxygen-free copper, which serves as the structural support and electrical interconnection structure of the drive circuit subunit 3 in the ceramic shell 1 to achieve the structural mechanical performance requirements and low on-resistance. The first chamber 2-1 accommodates the drive chip circuit elements of the drive circuit subunit, the second chamber 2-2 accommodates the drive circuit subunit circuit board, the third chamber 2-3 accommodates the power chip and the output channel of the upper half of the thermal management subunit, and the fourth chamber 2-4 accommodates the output channel of the lower half of the thermal management subunit.

[0041] The drive circuit subunit 3 is provided with mounting holes around it, and the interconnected metal pillars 2-7 in the ceramic shell 2 are brazed to achieve structural and electrical connection. The interconnected metal pillars 2-7 are in the form of step pillars, and the number of interconnected metal pillars 2-7 is not limited to 4, so as to achieve the longitudinal positioning of the drive circuit subunit. The drive circuit subunit 3 adopts a multi-layer wiring substrate, and the substrate material is alumina. The drive circuit subunit 3 can be designed and laid out according to different circuit requirements. The mounting holes on the drive circuit subunit are connected to the interconnected metal pillars 2-7 to achieve the high-power conduction requirements of the drive-power chip, and the structure is designed to achieve fool-proof installation. The position of the mounting holes is differentiated to achieve the effect of fool-proof installation, and the specific position layout includes but is not limited to trapezoidal and rectangular.

[0042] The thermal management subunit 1 includes a first layer 1-1 for mounting power chips, a second layer 1-2 which is airtightly connected to the fourth chamber 2-4 of the ceramic housing 2, and a third layer 1-3 which serves as an electrical output interface and a thermal output channel interface, wherein the first layer 1-1, the second layer 1-2 and the third layer 1-3 are stacked from top to bottom. The minimum size of the back step of the thermal management subunit 1 is obtained by thermal simulation calculation. A model of a double-sided boss is modeled using simulation software, and the corresponding thermal conduction physical parameters are assigned. The size of the first layer 1-1 for mounting power chips is fixed. It is only necessary to adjust the size of the third layer 1-3 of the thermal management subunit 1 to perform heat transfer simulation to obtain the minimum minimum size of the back step; the third layer 1-3 is the output surface of the thermal channel, and a stable temperature can be achieved by auxiliary heat dissipation. During the simulation process, radiation heat transfer and conduction heat transfer are used for simulation, so as to obtain the minimum minimum size of the back step. The ultimate goal of size reduction is to reduce the thermal stress when mounting on the device board. While ensuring heat dissipation, the stress with the PCB board is minimized during the subsequent mounting process and the reliability of the shell package is ensured. This packaging structure realizes the transformation of the discrete structure of the MOS chip circuit and the driving circuit to high integration and high reliability. The thermal management subunit 1 adopts a multi-layer structure, and the first layer 1-1 is mounted with the power chip to realize the power chip source electrical output and heat dissipation. The second layer 1-2 is airtightly connected to the metallization on the chamber 2-4 of the ceramic shell 2 by brazing. The third layer 1-3 is the electrical output interface and the thermal output channel interface. The above thermal management subunit structure processing methods include but are not limited to one-piece processing or layered welding. Materials include but are not limited to high thermal conductivity conductor materials such as tungsten copper, molybdenum copper, CPC, and CMC.

[0043] The ceramic shell 2 and the thermal management subunit 1 are welded at a first welding temperature, the upper surface of the thermal management subunit 1 and the power chip are welded at a second welding temperature, the upper surface of the drive circuit subunit 3 and the drive chip are welded at a third welding temperature, and the drive circuit subunit 3 and the ceramic shell 2 are welded at a fourth welding temperature, wherein the first welding temperature> the second welding temperature> the third welding temperature> the fourth welding temperature, forming multiple temperature gradients. Specifically, it refers to the process of welding the ceramic shell 2 and the thermal management subunit 1 with silver-copper solder of the shell during production at 780°C → the nano-silver sintered power chip with a sintering service temperature of 250°C> 500°C → the tin-silver-copper solder welding of the drive chip on the drive circuit subunit, the third welding temperature of which is 217-227°C → the lead-tin solder welding of the drive circuit subunit and the ceramic shell 2, the fourth welding temperature is 183°C, forming multiple temperature gradients. The power chip is sintered with nano-silver paste to achieve the requirements of low-temperature sintering, high-temperature service and low thermal resistance. The driving circuit subunit is sintered with tin-silver-copper solder, and the driving circuit subunit is connected to the ceramic shell by brazing with lead-tin solder to form multiple temperature gradients, so as to ensure that no remelting occurs during the device assembly process and to ensure the reliability of the device. In the present invention, subunits with multiple functions are integrated and interconnected in a package body through a ceramic shell to realize a package module with richer functions. The present invention distinguishes the thermal management and driving parts into units. The thermal management subunit is responsible for the heat dissipation of the power chip and part of the electrical connection function, while the driving circuit subunit performs switch control on the power chip to realize the predetermined function. The thermal management subunit dissipates heat through the channel at the bottom of the shell. Due to the low heat dissipation requirements, the driving circuit subunit is integrated inside the tube shell to realize the switch control of the power chip and input and output the corresponding electrical signals. The shell structure in the present invention reduces the mounting area on the board by optimizing the structure, so that the residual stress on the board during subsequent use is reduced, and the reliability of the package is improved.

[0044] Different from the traditional discrete power chip and drive circuit structure, the present invention stacks the drive chip and the power chip vertically to reduce the mounting area of ​​the overall packaged device on the PCB board, calculates the minimum step size on the back of the thermal management subunit through thermal simulation, and ensures the minimum stress on the PCB board during the subsequent mounting process and the reliability of the shell packaging while ensuring heat dissipation; the packaging structure of the present invention realizes the transformation of the discrete structure of the MOS chip circuit and the drive circuit to high integration and high reliability.

[0045] The material of the sealing ring 4 includes but is not limited to Kovar alloy 4J29 and porcelain sealing alloy 4J34, whose thermal expansion coefficient is more matched with ceramics, and can reduce the residual stress of brazing. The width of the sealing ring is ≥0.4mm, and the height is ≥0.4mm, which ensures the operability of parallel seam welding and the reliability of the shell sealing. The material of the sealing cover plate 5 includes but is not limited to Kovar alloy 4J42, and the shell is hermetically sealed by parallel seam welding. And it is ensured that the solder of each subunit does not remelt during the subsequent capping process. A 0.15mm thickening structure, i.e., a boss, is provided in the middle of the sealing cover plate 5, which plays a role in enhancing the strength and positioning of the cover plate.

[0046] The surface metallization and other metal parts in the present invention need to be plated with thin gold or thick gold according to the design, and the nickel plating range is 1.3-8.9μm; the gold plating range of the power chip welding surface and the bottom of the ceramic shell is 0.2-0.6μm, and the gold plating range of the remaining surfaces is 1.3-5.7μm.

[0047] The present invention discloses a packaging method for a longitudinally stacked integrated drive power module packaging structure, comprising the following steps:

[0048] S1. Select alumina black porcelain or aluminum nitride ceramic green porcelain tape with a specified thickness within the range of 0.1mm to 0.25mm according to the designed thickness, and mark the name of each layer for standby use;

[0049] S2, using laser ablation process to open holes in each layer of ceramic green tape according to a pre-designed hole pattern;

[0050] S3, using a printing machine to metallize and fill the through holes in step S2;

[0051] S4, using a printer to print surface metallization patterns on the layer where wiring is required;

[0052] S5, performing laser ablation to open a cavity on each layer of the ceramic raw tape according to a pre-designed cavity pattern;

[0053] S6, stacking and laminating the four-layer cavity once respectively to form four semi-finished products;

[0054] S7, printing the four semi-finished products with glue, and laminating them twice within the specified time;

[0055] S8, laminating and raw cutting the semi-finished product of the secondary lamination;

[0056] S9, finally performing cooked porcelain sintering by matching sintering process parameters;

[0057] S10, nickel plating and post-nickel heat treatment are performed on the metallized area of ​​the sintered ceramic part surface, and the ceramic part includes a ceramic housing and a substrate of a drive circuit subunit; in step S10, after chemical nickel plating of the ceramic part, the ceramic part is subjected to a heat treatment at 350°C to 400°C to recrystallize the Ni-P layer, and the heat treatment time is 30 to 40 minutes, which can alleviate the problems of coating peeling and blistering caused by compressive stress and ceramic strength reduction caused by tensile stress in large-area metallization plating, and increase the reliability of later bonding and mounting;

[0058] S11, heat treating and pre-nickel-plating metal parts, the metal parts including sealing rings, interconnecting metal pillars and thermal management subunits;

[0059] S12, placing the ceramic housing, the thermal management subunit, the interconnected metal column, the sealing ring and the silver-copper solder in a graphite mold prefabricated according to the design drawing in sequence, and welding them according to the process temperature curve of silver-copper brazing to form a semi-finished ceramic housing;

[0060] S13, performing chemical nickel plating and chemical gold plating on the ceramic housing and the substrate in the driving circuit subunit, and then protecting the thin gold area and performing electroplating and gold addition to form different thin gold and thick gold areas required by the design, thereby obtaining a finished ceramic housing;

[0061] S14. Use nano silver to sinter the power chip, sinter at low temperature and serve at high temperature, and achieve the low thermal resistance requirement of the solder layer after sintering;

[0062] S15. The drive circuit subunit is sintered with tin-silver-copper solder, and the drive circuit subunit is connected to the ceramic housing by brazing with lead-tin solder to form multiple temperature gradients.

[0063] The present invention adopts an innovative solution of vertical stacking of power chip and drive circuit, and conducts the electrical signal of the drive circuit to the bottom of the ceramic shell through the internal hole filling wiring of the ceramic. The thermal management subunit itself also serves as an electrical output channel, integrating heat dissipation with electrical functions. The drive circuit subunit is structurally and electrically connected to the metal column of the ceramic shell to achieve electrical connection with the power chip and low on-resistance and parasitic inductance. The interconnected metal columns achieve foolproofing through step-shaped design and prescribed distribution. The thickening structure is designed at the center of the sealing cover plate to enhance the strength and positioning of the cover plate. The structural design of the double-sided boss can reduce the mounting area of ​​the thermal management subunit on the board, reduce the structural stress during board-level installation, and improve reliability. Vertical stacking can reduce the area of ​​the original discrete structural design to 10mm×10mm, and can pass 500 rounds of -65℃~175℃ temperature cycle tests to achieve the same quality level as the discrete semiconductor device housing.

[0064] The present invention includes two subunits, and a transmission interface and a support structure are provided between the subunits, and the support structure and the transmission interface realize an integrated design; the upper and lower subunits are divided into a thermal management subunit and a drive circuit subunit according to their functions, wherein the thermal management subunit includes an efficient thermal management structure design to realize the heat extraction of the chip; the drive circuit subunit includes a ceramic substrate and a drive circuit, and the interconnection support of the two-stage subunits is realized through the interconnection of the transmission interface to reduce the influence of parasitic inductance. The ceramic shell provides a thermal management channel, a sealing structure, an interconnection structure and an input and output interface for the two-stage subunits. The heat output channel structure design on the ceramic shell reduces the mounting area of ​​the device on the board; the opening of the ceramic shell is hermetically sealed by a cover plate. The present invention solves the dilemma that the current drive and power chips occupy a large mounting area on the board, and realizes high integration, high reliability and low parasitic inductance.

[0065] The above-described multiple embodiments are convenient for those skilled in the art to better understand various aspects of the present invention. Those skilled in the art should be aware that they can easily use the present invention for performing the same purpose and / or other processes and structures that achieve the same advantages as the embodiments introduced herein, and those skilled in the art should also be aware that such equivalence does not deviate from the spirit and scope of the present invention, and they can make various changes, substitutions and modifications without deviating from the spirit and scope of the present invention.

Claims

1. A vertically stacked integrated driver power module packaging structure, characterized in that: The invention comprises a ceramic shell (2), a thermal management subunit (1) located in the inner cavity of the ceramic shell and arranged from bottom to top, a drive circuit subunit (3) serving as a drive circuit carrier, and a sealing cover plate (5) adapted to the ceramic shell (2) via a sealing ring (4); the ceramic shell (2) is a multi-layer cavity structure; the upper end of the ceramic shell (2) forms a seal with the sealing ring (4) and the sealing cover plate (5); the lower end of the ceramic shell (2) is electrically connected to the thermal management subunit (1) and forms a seal; a power chip is arranged on the upper surface of the thermal management subunit (1); a drive chip is arranged on the upper surface of the drive circuit subunit (3); and the drive circuit subunit (3) and the ceramic shell (2) are electrically interconnected.

2. The vertically stacked integrated driver power module packaging structure according to claim 1, characterized in that: The ceramic housing (2) comprises a first chamber (2-1), a second chamber (2-2), a third chamber (2-3) and a fourth chamber (2-4) arranged from top to bottom; a first electrical interface (2-5) is arranged at a step at a chamber junction between the first chamber (2-1) and the second chamber (2-2); a second electrical interface (2-6) and an interconnecting metal column (2-7) are arranged at a step at a chamber junction between the second chamber (2-2) and the third chamber (2-3); an output interface (2-8) is arranged on the bottom surface of the ceramic housing (2); and electrical signals of the first electrical interface (2-5) and the second electrical interface (2-6) are uniformly output through the output interface (2-8).

3. The longitudinally stacked integrated driver power module packaging structure according to claim 2, characterized in that: The first electrical interface (2-5), the second electrical interface (2-6) and the output interface (2-8) are connected by interlayer metallization hole filling and wiring, wherein the first electrical interface (2-5) is a signal interface of a drive circuit subunit, and is interconnected with the output interface (2-8) by metallization hole filling wiring to realize input and output of control signals; the second electrical interface (2-6) has a chip mounting position, a signal transmission interface and a high-power current transmission channel, and realizes extremely small on-resistance by low-resistance parallel metallization hole filling; the output interface (2-8) is arranged around the bottom of the ceramic housing (2) to realize input or output of signals and high-power current.

4. The longitudinally stacked integrated driver power module packaging structure according to claim 2, characterized in that: The drive circuit subunit (3) is provided with mounting holes around its periphery and is connected to the interconnecting metal columns (2-7) in the ceramic housing (2) by brazing to achieve structural and electrical connection. The interconnecting metal columns (2-7) are in the form of step columns to achieve longitudinal positioning of the drive circuit subunit.

5. The longitudinally stacked integrated driver power module packaging structure according to claim 2, characterized in that: The thermal management subunit (1) comprises a first layer (1-1) for mounting a power chip, a second layer (1-2) airtightly connected to a fourth chamber (2-4) of a ceramic housing (2), and a third layer (1-3) serving as an electrical output interface and a thermal output channel interface, wherein the first layer (1-1), the second layer (1-2), and the third layer (1-3) are stacked from top to bottom.

6. The longitudinally stacked integrated driver power module packaging structure according to claim 5, characterized in that: The minimum size of the back step of the thermal management subunit (1) is obtained through thermal simulation calculation, a simulation model of a double-sided boss is built, and corresponding thermal conduction physical parameters are assigned, and heat transfer simulation is performed to obtain the minimum size of the back step.

7. The longitudinally stacked integrated driver power module packaging structure according to claim 1, characterized in that: The ceramic shell (2) and the thermal management subunit (1) are welded at a first welding temperature, the upper surface of the thermal management subunit (1) and the power chip are welded at a second welding temperature, the upper surface of the drive circuit subunit (3) and the drive chip are welded at a third welding temperature, and the drive circuit subunit (3) and the ceramic shell (2) are welded at a fourth welding temperature, wherein the first welding temperature> the second welding temperature> the third welding temperature> the fourth welding temperature, thereby forming a plurality of temperature gradients.

8. The vertically stacked integrated driver power module according to claim 1, characterized in that: The driving circuit subunit (3) adopts a multi-layer wiring substrate, and the substrate material is aluminum oxide.

9. A packaging method for the longitudinally stacked driver-integrated power module packaging structure according to any one of claims 1 to 8, characterized in that: The steps include: S1. Select alumina black porcelain or aluminum nitride ceramic green porcelain tape according to the designed thickness, mark the name of each layer and keep it ready for use; S2, using laser ablation process to open holes in each layer of ceramic green tape according to a pre-designed hole pattern; S3, using a printing machine to metallize and fill the through holes in step S2; S4, using a printer to print surface metallization patterns on the layer where wiring is required; S5, performing laser ablation to open a cavity on each layer of the ceramic raw tape according to a pre-designed cavity pattern; S6, stacking and laminating the four-layer cavity once respectively to form four semi-finished products; S7, printing the four semi-finished products with glue, and laminating them twice within the specified time; S8, laminating and raw cutting the semi-finished product of the secondary lamination; S9, finally performing cooked porcelain sintering by matching sintering process parameters; S10, performing nickel plating and post-nickel heat treatment on the metallized area on the surface of the sintered ceramic component, wherein the ceramic component includes a ceramic housing and a substrate of a drive circuit subunit; S11, heat treating and pre-nickel-plating metal parts, the metal parts including sealing rings, interconnecting metal pillars and thermal management subunits; S12, placing the ceramic housing, the thermal management subunit, the interconnected metal column, the sealing ring and the silver-copper solder in a graphite mold prefabricated according to the design drawing in sequence, and welding them according to the process temperature curve of silver-copper brazing to form a semi-finished ceramic housing; S13, chemically nickel-plating and chemically gold-plating the ceramic housing and the substrate in the driving circuit subunit, and then protecting the thin gold area and electroplating gold to form different thin gold and thick gold areas required by the design, to obtain a finished ceramic housing.

10. The packaging method of a vertically stacked integrated driver power module packaging structure according to claim 1, characterized in that: In the step S10, after the ceramic part is electrolessly nickel-plated, it is subjected to heat treatment at 350° C. to 400° C. to recrystallize the Ni-P layer, and the heat treatment time is 30 to 40 minutes.

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