IGBT (Insulated Gate Bipolar Translator) chip heat dissipation packaging module and packaging method

Abstract

The invention discloses an IGBT (Insulated Gate Bipolar Translator) chip heat dissipation packaging module and a packaging method. The packaging method comprises the following steps: cleaning and preprocessing the back surface of an IGBT chip, etching a micro-channel network on the back surface, and depositing a graphene film on the inner wall by utilizing a chemical vapor deposition method to form a heat conduction channel; manufacturing a microfluid distributor, and connecting the microfluid distributor with the back surface of the chip through an alignment and bonding technology to form a complete cooling liquid circulation channel; the front surface of the IGBT chip is fixed on a circuit substrate by using a conductive bonding material and is interconnected with a circuit on the circuit substrate; packaging the IGBT chip and the microfluid distributor by using a packaging material to obtain an IGBT integrated module; for the structural characteristics of the IGBT chip, a microfluid heat dissipation system and an efficient heat conduction channel are creatively integrated, the heat dissipation effect and the working stability of the IGBT chip are remarkably improved, and the service life of the chip is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of chip packaging, and particularly to an IGBT chip heat dissipation packaging module and a packaging method. Background Art

[0002] In recent years, Insulated Gate Bipolar Transistors (IGBTs) have been widely used in high-power and high-frequency industrial applications, such as electric vehicles, renewable energy power generation systems, industrial motor drives, and power transmission and distribution systems. These application scenarios pose stringent requirements of high current, high voltage, and high-speed switching on IGBT chips, resulting in a large amount of heat generated during chip operation. If heat cannot be dissipated in a timely and effective manner, the performance and reliability of the chip will be severely affected, potentially leading to a decrease in efficiency, unstable operation, and even thermal failure. Therefore, improving the heat dissipation ability of IGBT chips to ensure their stable operation under high power density and high frequency conditions has become the focus of attention in the industry.

[0003] In existing chip heat dissipation integration technologies, heat sinks are usually pasted on the back of the chip, high thermal conductivity interface materials are used, or the chip is packaged on a substrate with heat dissipation functions to assist in heat conduction and dissipation. However, these traditional heat dissipation methods have certain limitations. For example, the heat conduction efficiency of heat sinks and thermal interface materials is limited and cannot meet the rapid heat dissipation requirements of high-power IGBT chips; packaging the chip on a heat dissipation substrate, although improving the heat dissipation ability to a certain extent, has a large thermal resistance due to the need for heat to pass through multiple interfaces, resulting in poor heat dissipation effects. In addition, it is difficult to achieve a refined heat dissipation channel layout inside the chip in existing integration technologies, and it is impossible to effectively control the heat density in different regions of the chip. These drawbacks lead to heat accumulation inside the chip, forming hot spot areas, seriously affecting the working stability and lifespan of IGBT chips, and restricting their development in higher power and higher frequency applications.

[0004] In view of this, it is necessary to improve the chip heat dissipation integration technology in the prior art to solve the problem that it cannot meet the high heat dissipation performance requirements of the chip. Summary of the Invention

[0005] The purpose of the present invention is to provide an IGBT chip heat dissipation packaging module and a packaging method to solve the above technical problems.

[0006] To achieve this purpose, the present invention adopts the following technical solutions: A packaging method for an IGBT chip heat dissipation packaging module, comprising: S1. Clean and pre-treat the backside of the IGBT chip, and etch a pre-designed microchannel network on the backside of the IGBT chip substrate using etching technology. S2. Use chemical vapor deposition to deposit a graphene film on the inner wall of the microchannel network to form a heat conduction channel. S3. Fabricate a microfluidic dispenser that matches the microchannel network, and connect the microfluidic dispenser to the microchannel network on the backside of the chip through alignment and bonding technology to form a complete coolant circulation channel; the microfluidic dispenser has an inlet and an outlet for the coolant. S4. On the front side of the IGBT chip, use a conductive adhesive material to fix the IGBT chip on the circuit board, and use laser cladding technology to interconnect the electrodes of the IGBT chip with the circuits on the circuit board. S5. Use a packaging material to package the IGBT chip and the microfluidic dispenser to obtain an IGBT integrated module.

[0007] Optionally, step S1 specifically includes: S11. Place the backside of the IGBT chip in an ultrasonic cleaning device, and perform multi-stage cleaning successively with acetone, absolute ethanol, and deionized water, with each cleaning time being 5 minutes, and then dry the IGBT chip. S12. Use plasma surface treatment technology to activate the backside of the dried IGBT chip, with the plasma power being 100 W and the treatment time being 2 minutes. S13. Use a spin-coating process to uniformly coat a layer of positive photoresist on the backside of the IGBT chip, with the spin-coating speed being 4000 rpm and the spin-coating time being 40 seconds to form a photoresist coating with a thickness of 1.5 microns; then pre-bake the IGBT chip coated with the positive photoresist on a hot plate at a temperature of 90 °C for 2 minutes to remove the solvent in the photoresist.

[0008] Optionally, after step S13, it further includes: S14. Use ultraviolet lithography technology, through an intelligent alignment system, to align and transfer the photomask of the pre-designed microchannel network pattern onto the photoresist layer. S15. Place the exposed IGBT chip in a developer at 25 °C for development to complete the patterning process of the IGBT chip; among them, the development time is 60 seconds, and the developer is a 2.38% concentration of tetramethylammonium hydroxide solution; after development, rinse the surface of the IGBT chip with deionized water to remove the residual developer, and then dry it in a nitrogen environment. S16. Using deep reactive ion etching technology, anisotropically etch the back side of the patterned chip substrate; the etching parameters are set as follows: the etching gas is SF 6 and C 4 F 8 . The gas flow rates are 130 sccm and 85 sccm respectively, the RF power is 800 W, the number of etching cycles is 200 times, the time for each cycle is 7 seconds, and the total etching depth is 50 microns to form a pre-designed microchannel network structure; S17. After the etching process is completed, perform multi-stage cleaning successively with acetone, absolute ethanol, and deionized water, and then dry it to obtain the back side of the IGBT chip substrate with a microchannel network structure.

[0009] Optionally, step S2 specifically includes: S21. Place the IGBT chip in a plasma cleaning equipment and use argon plasma to perform surface activation treatment on the inner wall of the microchannel network. The plasma power is 150 W and the treatment time is 3 minutes; S22. In a chemical vapor deposition system, fix the IGBT chip on a quartz substrate carrier table with the inner wall of the microchannel network facing the direction of the reaction gas flow; S23. Evacuate the CVD reaction chamber of the chemical vapor deposition system to reach a base pressure of 1×10⁻ 4 Pa; introduce high-purity hydrogen and argon for pre-cleaning. The gas flow rates are 200 sccm and 500 sccm respectively, and the temperature is raised to 800 °C and maintained for 30 minutes; S24. Raise the reaction temperature of the CVD reaction chamber to 1000 °C. Under the regulation of the control system, introduce the carbon source gases methane, hydrogen, and argon required for graphene growth. The gas flow rates are: methane 20 sccm, hydrogen 100 sccm, and argon 500 sccm; S25. Start the graphene deposition process. The deposition time is 15 minutes. Use an on-line monitoring device to detect the gas composition in the CVD reaction chamber and the graphene growth situation on the inner wall of the microchannel in real time.

[0010] Optionally, after step S25, it further includes: S26. After the deposition is completed, stop introducing methane gas, keep the flow rates of hydrogen and argon unchanged, gradually cool down to 800 °C, and perform an annealing treatment for 10 minutes; then continue to cool down, during which stop hydrogen and keep argon introduced; S27. When the temperature drops below 50 °C, restore the CVD reaction chamber to atmospheric pressure; then take out the deposited IGBT chip from the CVD reaction chamber; S28. Use a Raman spectrometer to detect the graphene film on the inner wall of the microchannel network to confirm the number of layers and crystal quality of the graphene film, and measure the thickness of the film by an optical scanning device.

[0011] Optionally, step S3 specifically includes: S31. According to the design parameters of the microchannel network of the IGBT chip, use computer design software to draw the three-dimensional model structure of the microfluidic dispenser. The three-dimensional model structure includes a coolant inlet, an outlet, and an internal microchannel structure. S32. Select glass material or quartz material as the base body of the microfluidic dispenser, and use laser micromachining technology to machine through coolant inlet and outlet holes, and a semi-open structure of the internal microchannels on the base body. S33. Use micro-machining technology to engrave a microchannel pattern corresponding to the microchannel network on the surface of the base body, with a depth of 50 microns and a width of 100 microns, to obtain a microfluidic dispenser. S34. Perform chemical treatment on the surface of the microfluidic dispenser, use hydrofluoric acid solution to smooth and corrode its surface, and then thoroughly clean it with deionized water and dry it for use.

[0012] Optionally, after step S34, it further includes: S35. Adopt plasma surface activation technology, use plasma to activate the bonding surfaces of the microfluidic dispenser and the back of the IGBT chip. The plasma power is 200 W and the treatment time is 2 minutes. S36. Through an alignment device, with the assistance of a vision device, align the microchannel pattern of the microfluidic dispenser with the inlet and outlet of the microchannel network on the back of the IGBT chip. S37. Adopt anodic bonding technology to bond the aligned microfluidic dispenser with the microchannel network on the back of the IGBT chip; in a vacuum environment, apply a voltage of 1000 V, a temperature of 400 °C, a pressure of 500 N, and a bonding time of 30 minutes. S38. Perform a sealing test on the bonded IGBT chip assembly, and use a helium mass spectrometer leak detector for leak detection. S39. Install micro connectors and sealing washers at the inlet and outlet of the coolant of the microfluidic dispenser, and use epoxy resin glue or welding technology to fix the micro connectors.

[0013] Optionally, step S4 specifically includes: S41. Perform surface pretreatment on the front of the IGBT chip, and use a mixed plasma of argon and oxygen to perform plasma cleaning on the front of the chip. S42: On the area to be installed on the circuit board, use a dispensing device to evenly coat a layer of conductive adhesive material with a thickness of 50 microns; at the same time, coat the conductive adhesive material at the corresponding position on the back of the IGBT chip; the conductive adhesive material is a conductive adhesive containing silver nanoparticles; S43: Through a mounting device, place the pre-treated IGBT chip face down. Through a visual recognition system, align the chip electrodes with the corresponding electrode pads on the circuit board, and perform alignment and mounting of the IGBT chip with the circuit board coated with the conductive adhesive material; S44: Place the mounted component in a hot pressing and curing device, and perform hot pressing and curing according to the curing process curve of the conductive adhesive material; the curing temperature is gradually raised to 180 °C, the pressure is maintained at 1 MPa, and the curing time is 60 minutes; S45: After curing, use laser cladding technology to interconnect the electrodes of the IGBT chip with the circuit on the circuit board.

[0014] Optionally, after step S5, it further includes: S6: Conduct a coolant circulation test on the packaged IGBT integrated module, check the sealing performance and fluid circulation of the coolant circulation channel, and perform electrical and thermal performance tests to determine whether the IGBT integrated module meets the design requirements.

[0015] The present invention also provides an IGBT chip heat dissipation packaging module, including the packaging method of the IGBT chip heat dissipation packaging module as described above. The IGBT chip heat dissipation packaging module includes: An IGBT chip body, on the back of which a microchannel network is provided; A heat conduction channel of a graphene film, arranged on the inner wall of the microchannel network; A microfluidic distributor, which matches the microchannel network and has an inlet and an outlet for the coolant. Through alignment and bonding technology, the microfluidic distributor is connected to the microchannel network on the back of the IGBT chip to form a complete coolant circulation channel.

[0016] Compared with the prior art, the present invention has the following beneficial effects: First, the back surface of the IGBT chip is cleaned and pre-treated, and then an etched technique is used to etch a pre-designed microchannel network on the back surface of the chip substrate. The chemical vapor deposition method is utilized to deposit a graphene film with high thermal conductivity on the inner wall of the microchannel network to form an efficient heat conduction channel, enhancing the heat conduction performance of the microchannel; a microfluidic distributor matching the microchannel network is fabricated, and through alignment and bonding techniques, the microfluidic distributor is connected to the microchannel network on the back surface of the chip to form a complete coolant circulation channel. The microfluidic distributor has an inlet and an outlet for the coolant to ensure the effective circulation of the coolant; on the front surface of the IGBT chip, a conductive adhesive material is used to fix the IGBT chip on the circuit board, and a laser cladding technique is adopted to interconnect the electrodes of the IGBT chip with the circuits on the circuit board, achieving high reliability of the electrical connection; a packaging material is used to package the IGBT chip and the microfluidic distributor, and finally an IGBT integrated module with good heat dissipation performance and mechanical strength is obtained; this method innovatively integrates a microfluidic heat dissipation system and an efficient heat conduction channel according to the structural characteristics of the IGBT chip, significantly improving the heat dissipation effect and working stability of the IGBT chip, prolonging the service life of the chip, and being applicable to high-power and high-frequency industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] The structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions under which the present invention can be implemented. Therefore, they do not have substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention.

[0019] Figure 1 It is one of the flow diagrams of the packaging method of the IGBT chip heat dissipation packaging module in Embodiment 1; Figure 2 It is the second of the flow diagrams of the packaging method of the IGBT chip heat dissipation packaging module in Embodiment 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] In order to make the object, features, and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be intermediate components present simultaneously.

[0022] The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and through specific embodiments.

[0023] Embodiment 1: Combined with Figures 1 to 2 As shown, the embodiment of the present invention provides a packaging method for an IGBT chip heat dissipation packaging module, including: S1, cleaning and preprocessing the back surface of the IGBT chip, and etching a pre-designed microchannel network on the back surface of the IGBT chip substrate by using an etching technique; Thoroughly cleaning and preprocessing the back surface of the IGBT chip is crucial. The cleaning process can remove organic contaminants, particulate matter, and oxide layers existing on the back surface, ensuring the effectiveness of subsequent processes. Subsequently, a pre-designed microchannel network structure is etched on the back surface of the chip substrate by using a precise etching technique (such as deep reactive ion etching DRIE). These microchannel networks will be used to enhance the heat dissipation capacity of the chip, enabling the chip to dissipate heat quickly and effectively during high-power operation, and improving the performance and reliability of the chip.

[0024] S2, using chemical vapor deposition to deposit a graphene film on the inner wall of the microchannel network to form a heat conduction channel; Chemical vapor deposition (CVD) is used to deposit high-quality graphene films on the inner wall of the microchannel network. Graphene has extremely high thermal conductivity and can significantly improve the thermal conductivity in the microchannel. By depositing graphene films on the inner wall of the microchannel, an efficient heat conduction channel is formed, so that the heat generated by the chip can be quickly transferred to the cooling medium. This process requires precise control of CVD process parameters such as temperature, gas flow rate and deposition time to ensure the uniformity and thermal conductivity of the graphene film. At the same time, the deposition of the graphene film needs to be highly matched with the microchannel structure to ensure the continuity and effectiveness of the heat conduction channel.

[0025] S3, making a microfluid dispenser matching the microchannel network, connecting the microfluid dispenser to the microchannel network on the back of the chip through alignment and bonding technology to form a complete coolant circulation channel; the microfluid dispenser has an inlet and an outlet for the coolant; Design and make a microfluidic dispenser that matches the microchannel network on the back of the IGBT chip. The microfluidic dispenser needs to have an inlet and outlet for the coolant, as well as an internal microchannel structure to guide the coolant to circulate in the microchannel network. Use computer design software to draw a three-dimensional model of the microfluidic dispenser to ensure that it accurately corresponds to the size and position of the chip microchannel. Then, the microfluidic dispenser is made using precision machining technology. In a clean environment, use a high-precision alignment device to accurately align the microfluidic dispenser with the microchannel network on the back of the chip. Use reliable bonding technology (such as anodic bonding or bonding) to firmly connect the two together to form a closed coolant circulation channel. The successful implementation of this step ensures that the coolant can effectively enter the microchannel network and take away the heat generated when the chip is working.

[0026] S4, fixing the IGBT chip on the circuit substrate using a conductive adhesive material on the front side of the IGBT chip, and interconnecting the electrodes of the IGBT chip with the circuit on the circuit substrate using a laser cladding technology; Mounting the IGBT chip on the circuit substrate is a key step. First, a conductive adhesive material (such as silver-containing conductive glue) is applied to the front of the chip and the corresponding position of the circuit substrate to ensure the reliability of mechanical fixation and electrical connection. Then, the chip is accurately mounted on the circuit substrate, and the conductive adhesive material is cured through processes such as hot pressing and curing to form a stable connection. Subsequently, laser cladding technology is used to interconnect the electrodes of the IGBT chip with the circuits on the circuit substrate. Laser cladding technology has the characteristics of high precision and low heat-affected zone, and can form low-resistance and high-reliability electrical connections.

[0027] S5, using packaging materials to package the IGBT chip and the microfluid dispenser to obtain an IGBT integrated module.

[0028] The assembled IGBT chip and the microfluidic dispenser are integrally encapsulated. The encapsulation material is usually selected from materials with good insulation, thermal conductivity, and mechanical protection capabilities (such as epoxy resin or encapsulation glue that meets specific requirements). The encapsulation process needs to be carried out in a clean environment to ensure that no impurities or bubbles are mixed into the encapsulation material. The purpose of encapsulation is to protect the chip and the microfluidic dispenser from the influence of the external environment, such as humidity, dust, and mechanical stress, while providing additional mechanical strength and heat dissipation paths.

[0029] The working principle of the present invention is as follows: First, clean and pre-treat the back of the IGBT chip, and then use etching technology to etch a pre-designed microchannel network on the back of the chip substrate. Use chemical vapor deposition to deposit a graphene film with high thermal conductivity on the inner wall of the microchannel network to form an efficient heat conduction channel, enhancing the thermal conductivity of the microchannel; fabricate a microfluidic dispenser that matches the microchannel network, and connect the microfluidic dispenser to the microchannel network on the back of the chip through alignment and bonding technologies to form a complete coolant circulation channel. The microfluidic dispenser has an inlet and an outlet for the coolant to ensure effective circulation of the coolant; on the front of the IGBT chip, use a conductive adhesive material to fix the IGBT chip on the circuit board, and use laser cladding technology to interconnect the electrodes of the IGBT chip with the circuits on the circuit board to achieve high reliability of electrical connection; use encapsulation material to encapsulate the IGBT chip and the microfluidic dispenser to finally obtain an IGBT integrated module with good heat dissipation performance and mechanical strength; this method innovatively integrates a microfluidic heat dissipation system and an efficient heat conduction channel according to the structural characteristics of the IGBT chip, significantly improving the heat dissipation effect and working stability of the IGBT chip, extending the service life of the chip, and being applicable to high-power and high-frequency industrial applications.

[0030] In this embodiment, specifically, step S1 specifically includes: S11, place the back of the IGBT chip in an ultrasonic cleaning device, and perform multi-stage cleaning in sequence with acetone, absolute ethanol, and deionized water, with each cleaning time being 5 minutes, and then dry the IGBT chip; The cleaning process is to remove organic pollutants, particulate matter, and oxide layers on the back of the chip; after cleaning, place the chip in a clean and dry environment and dry it in an oven at a temperature of 100 °C for 10 minutes to ensure that there is no residual moisture on the surface.

[0031] S12, use plasma surface treatment technology to activate the back of the dried IGBT chip, with a plasma power of 100 W and a treatment time of 2 minutes; to improve the adhesion of the photoresist in subsequent processes.

[0032] S13. A positive photoresist is uniformly coated on the back of the IGBT chip by a spin coating process at a spin speed of 4000 rpm for 40 seconds to form a photoresist coating with a thickness of 1.5 microns. Then, the IGBT chip coated with the positive photoresist is pre-baked on a hot plate at a temperature of 90 °C for 2 minutes to remove the solvent in the photoresist.

[0033] S14. By using ultraviolet lithography technology and through an intelligent alignment system, the photomask of the pre-designed microchannel network pattern is aligned and transferred onto the photoresist layer. The exposure energy is 150 mJ / cm² and the exposure time is 10 seconds to ensure the high resolution and accuracy of the microchannel pattern.

[0034] S15. The exposed IGBT chip is placed in a developer at 25 °C for development to complete the patterning of the IGBT chip. Among them, the development time is 60 seconds, and the developer is a 2.38% concentration of tetramethylammonium hydroxide solution. After development, the surface of the IGBT chip is rinsed with deionized water to remove the residual developer, and then dried in a nitrogen environment.

[0035] To enhance the etching resistance of the microchannel pattern, the developed IGBT chip is placed on a hot plate at a temperature of 120 °C for post-baking for 5 minutes to fully crosslink the photoresist and enhance the corrosion resistance.

[0036] S16. By using deep reactive ion etching technology, anisotropic etching is performed on the back of the patterned chip substrate. The etching parameters are set as follows: the etching gases are SF 6 and C 4 F 8 , the gas flow rates are 130 sccm and 85 sccm respectively, the radio frequency power is 800 W, the etching cycle number is 200 times, and the time for each cycle is 7 seconds. The total etching depth is 50 microns to form the pre-designed microchannel network structure.

[0037] S17. After the etching process is completed, multi-stage cleaning is performed successively with acetone, absolute ethanol, and deionized water, and then drying is carried out to obtain the back of the IGBT chip substrate with a microchannel network structure.

[0038] Specifically, the residual photoresist on the back of the IGBT chip is completely removed by using an organic solvent (such as acetone). Subsequently, the surface of the chip is cleaned successively with deionized water and absolute ethanol. Finally, in a clean and dry environment, it is dried with nitrogen or placed in an oven at a temperature of 100 °C for 5 minutes to obtain the back of the IGBT chip substrate with a microchannel network structure.

[0039] Use an optical scanning device to inspect the etched microchannel network structure to confirm that the size, morphology, and position of the microchannels meet the preset design requirements; if defects are found, record them and make corresponding process adjustments.

[0040] In this embodiment, specifically, step S2 specifically includes: S21, Place the IGBT chip in a plasma cleaning device and use argon plasma to perform surface activation treatment on the inner wall of the microchannel network. The plasma power is 150 W and the treatment time is 3 minutes; to remove residual organic matter and oxide layers on the inner wall of the microchannel and enhance the adhesion of the graphene film.

[0041] S22, In a chemical vapor deposition system, fix the IGBT chip on a quartz substrate carrier table so that the inner wall of the microchannel network faces the reaction gas flow direction; use a robotic arm to automatically load the chip into the CVD reaction chamber to avoid contamination introduced by manual operation.

[0042] S23, Evacuate the CVD reaction chamber of the chemical vapor deposition system to reach a base pressure of 1×10⁻ 4 Pa; Introduce high-purity hydrogen and argon for pre-cleaning. The gas flow rates are 200 sccm and 500 sccm respectively, and the temperature is raised to 800 °C and maintained for 30 minutes; to further remove surface impurities on the inner wall of the microchannel.

[0043] S24, Raise the reaction temperature of the CVD reaction chamber to 1000 °C. Under the regulation of the control system, introduce the carbon source gases methane, hydrogen, and argon required for graphene growth. The gas flow rates are: methane 20 sccm, hydrogen 100 sccm, and argon 500 sccm; maintain the pressure in the CVD reaction chamber at 500 Pa.

[0044] S25, Start the graphene deposition process. The deposition time is 15 minutes. Use an on-line monitoring device to continuously detect the gas composition in the CVD reaction chamber and the graphene growth on the inner wall of the microchannel; ensure the continuity and high quality of the graphene film.

[0045] S26, After deposition, stop the introduction of methane gas, keep the flow rates of hydrogen and argon unchanged, gradually cool down to 800 °C, and perform an annealing treatment for 10 minutes; to improve the crystal quality and thermal conductivity of the graphene film. Then continue the cooling process, during which stop hydrogen and keep argon introduced; prevent the graphene film from being oxidized during the cooling process; during the cooling process, the intelligent control system continuously monitors the temperature and atmosphere changes to ensure the stability of the cooling process.

[0046] S27. When the temperature drops below 50°C, restore the CVD reaction chamber to atmospheric pressure; then take out the deposited IGBT chip from the CVD reaction chamber. Use a robotic arm to take out the deposited IGBT chip from the reaction chamber and place it in a clean environment protected by inert gas to prevent the graphene film from being affected by water vapor and oxygen in the air.

[0047] S28. Use a Raman spectrometer to detect the graphene film on the inner wall of the microchannel network to confirm the number of layers and crystal quality of the graphene film, and measure the thickness of the film with an optical scanning device; ensure that the thickness is uniform between 1 - 2 nanometers, meeting the requirements of high thermal conductivity.

[0048] For chips whose detection results do not meet the requirements, the intelligent system automatically adjusts the CVD process parameters, such as deposition temperature, gas flow rate, and deposition time, and repeats steps S24 to S28 until the quality of the graphene film reaches the preset standard.

[0049] Perform surface protection treatment on the IGBT chips that meet the quality requirements, and coat a layer of peelable protective film at the inlet and outlet of the microchannel network to prevent impurities from entering the microchannel during subsequent processes and maintain the integrity of the graphene film.

[0050] In this embodiment, specifically, step S3 specifically includes: S31. According to the design parameters of the microchannel network of the IGBT chip, use computer design software to draw the three - dimensional model structure of the microfluidic dispenser. The three - dimensional model structure includes a coolant inlet, an outlet, and an internal microchannel structure; ensure precise matching with the inlet and outlet positions and dimensions of the microchannel network.

[0051] S32. Select a glass material (such as borosilicate glass) or quartz material with high transparency, high heat resistance, and chemical corrosion resistance as the substrate body of the microfluidic dispenser, and use laser micro - machining technology to process through - holes for the coolant inlet and outlet, and a semi - open structure for the internal microchannels on the substrate body; To meet the requirements of heat dissipation performance and reliability; use ultra - precision machining technology (such as ultraviolet laser micro - machining or precision grinding) to process through - holes for the coolant inlet and outlet, and a semi - open structure for the internal microchannels on the substrate.

[0052] S33. Use micro - mechanical machining technology to engrave a microchannel pattern corresponding to the microchannel network on the surface of the substrate body, with a depth of 50 microns and a width of 100 microns, to obtain a microfluidic dispenser; the surface roughness Ra is less than 0.1 micron to ensure the smoothness and dimensional accuracy of the flow channel.

[0053] S34. Chemically treat the surface of the microfluidic dispenser. Smoothly etch its surface using a hydrofluoric acid solution, then thoroughly clean it with deionized water and dry it for later use.

[0054] To reduce the microscopic defects on the surface of the microchannel and improve the fluid flow performance; subsequently, thoroughly clean it with deionized water and dry it for later use.

[0055] S35. Adopt the plasma surface activation technology. Use plasma to activate the bonding surfaces of the microfluidic dispenser and the back of the IGBT chip. The plasma power is 200 W and the treatment time is 2 minutes; to enhance the bonding force between the two components.

[0056] S36. Through an alignment device (such as a six-axis precision alignment platform), with the assistance of a vision device, align the microchannel pattern of the microfluidic dispenser with the inlets and outlets of the microchannel network on the back of the IGBT chip; the alignment error is controlled within ±2 microns to ensure seamless connection of the channels.

[0057] S37. Adopt the anodic bonding technology to bond the aligned microfluidic dispenser with the microchannel network on the back of the IGBT chip; in a vacuum environment, apply a voltage of 1000 V, a temperature of 400 °C, a pressure of 500 N, and a bonding time of 30 minutes; achieve a firm bond between the glass and the silicon to form a closed coolant circulation channel.

[0058] After the bonding is completed, gradually cool it to room temperature to prevent cracks from occurring at the bonding interface due to thermal stress caused by a sudden temperature drop; maintain the voltage during the cooling process until the temperature drops below 100 °C.

[0059] S38. Conduct a sealing test on the bonded IGBT chip assembly. Use a helium mass spectrometer leak detector for leak detection; ensure that the sealing performance of the microfluidic channel meets the requirements.

[0060] Conduct a coolant flow performance test on the components that pass the sealing test. Connect a precision microflow pump and introduce a coolant with a predetermined flow rate (such as deionized water or a special coolant). Use the Micro Particle Image Velocimetry (μPIV) technology to observe the flow state of the coolant in the microchannel network to ensure that the flow channel is unblocked and the flow is uniform.

[0061] S39. Install a micro connector and a sealing gasket at the inlets and outlets of the coolant of the microfluidic dispenser. Fix the micro connector using epoxy resin glue or welding technology. Ensure the reliability and sealing of the coolant pipeline connection.

[0062] In this embodiment, specifically, step S4 specifically includes: S41. Perform surface pretreatment on the front side of the IGBT chip. Use a mixed plasma of argon and oxygen to clean the front side of the chip; the plasma power is 150 W and the treatment time is 2 minutes to remove surface organic contaminants and oxide layers, enhance the adhesion of the conductive bonding material, and make the chip surface in an activated state.

[0063] S42: On the area to be installed on the circuit board, use a dispensing device to evenly coat a layer of conductive bonding material with a thickness of 50 microns; at the same time, coat the conductive bonding material at the corresponding position on the back side of the IGBT chip; the conductive bonding material is a conductive adhesive containing silver nanoparticles.

[0064] S43: Through a mounting device, place the pretreated IGBT chip face down. Through a vision recognition system, align the chip electrodes with the corresponding electrode pads on the circuit board, and perform alignment and mounting of the IGBT chip with the circuit board coated with the conductive bonding material; the alignment accuracy is controlled within ±5 microns; during the mounting process, apply a constant mounting pressure (such as 500 kPa) to ensure full contact between the chip and the substrate and eliminate air bubbles in the adhesive layer.

[0065] S44: Place the mounted component in a hot press curing device and perform hot press curing according to the curing process curve of the conductive bonding material; the curing temperature is gradually raised to 180 °C, the pressure is maintained at 1 MPa, and the curing time is 60 minutes; during this process, use an intelligent temperature and pressure control system to precisely adjust the curing parameters to ensure that the conductive bonding material is fully cured to form a stable mechanical and electrical connection.

[0066] S45: After curing, use laser cladding technology to interconnect the electrodes of the IGBT chip with the circuits on the circuit board.

[0067] Specifically: Use a high-precision laser cladding device, select high-purity metal powder with a diameter of 20 microns (such as silver powder or copper powder) as the cladding material; under a protective atmosphere (such as nitrogen), set the laser power to 200 W and the scanning speed to 10 mm / s, and cladding the cladding material on the connection area between the chip electrodes and the substrate circuits; through the metallurgical bonding of the cladding layer, form a low-resistance and high-reliability electrical interconnection to improve the electrical performance and long-term stability of the module.

[0068] In this embodiment, it is further explained that after step S5, it further includes: S6. Perform a coolant circulation test on the packaged IGBT integrated module, check the sealing performance of the coolant circulation channel and the fluid circulation situation, and perform electrical performance and thermal performance tests to determine whether the IGBT integrated module meets the design requirements.

[0069] Comprehensively test and verify the packaged IGBT integrated module. First, conduct a coolant circulation test. By introducing coolant, check the tightness of the microchannel network and the microfluidic distributor and the fluid circulation situation to ensure there is no leakage or blockage. Use measuring equipment to monitor the flow rate, pressure, and temperature changes of the coolant to verify the performance of the cooling system. Subsequently, conduct electrical performance tests, measure the switching characteristics, on-resistance, and insulation performance of the IGBT module to ensure that the electrical performance meets the specification requirements. Then, conduct thermal performance tests. Under simulated actual working conditions, evaluate the heat dissipation capacity and temperature stability of the module. By comprehensively analyzing the test data, determine whether the IGBT integrated module meets the design requirements. If the test results meet the standards, the module can be put into use; if there are deviations, the reasons need to be analyzed and corresponding improvements and adjustments need to be made.

[0070] Embodiment 2: The present invention also provides an IGBT chip heat dissipation packaging module, including the packaging method of the IGBT chip heat dissipation packaging module as described above. The IGBT chip heat dissipation packaging module includes: The IGBT chip body, on the back of which a microchannel network is provided; the pre-designed microchannel network is etched using etching technology, and these microchannels are used to enhance the heat dissipation capacity of the chip.

[0071] The heat conduction channels of the graphene film are arranged on the inner wall of the microchannel network; the graphene film is deposited by chemical vapor deposition. Graphene has excellent thermal conductivity, forming efficient heat conduction channels to improve the heat dissipation efficiency of the chip.

[0072] The microfluidic distributor, which matches the microchannel network, has an inlet and an outlet for the coolant. Through alignment and bonding technologies, the microfluidic distributor is connected to the microchannel network on the back of the IGBT chip to form a complete coolant circulation channel, realizing effective cooling of the chip.

[0073] As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A packaging method for an IGBT chip heat dissipation packaging module, characterized in that: include: S1, cleaning and pre-treating the back side of the IGBT chip, and etching a pre-designed microchannel network on the back side of the IGBT chip substrate using an etching technique; S2, using chemical vapor deposition to deposit a graphene film on the inner wall of the microchannel network to form a heat conduction channel; S3, making a microfluid dispenser matching the microchannel network, connecting the microfluid dispenser to the microchannel network on the back of the chip through alignment and bonding technology to form a complete coolant circulation channel; the microfluid dispenser has an inlet and an outlet for the coolant; S4, fixing the IGBT chip on the circuit substrate using a conductive adhesive material on the front side of the IGBT chip, and interconnecting the electrodes of the IGBT chip with the circuit on the circuit substrate using a laser cladding technology; S5, using packaging materials to package the IGBT chip and the microfluid dispenser to obtain an IGBT integrated module.

2. The packaging method of the IGBT chip heat dissipation packaging module according to claim 1, characterized in that: Step S1 specifically includes: S11, placing the back side of the IGBT chip in an ultrasonic cleaning device, and performing multi-stage cleaning using acetone, anhydrous ethanol and deionized water in sequence, each cleaning time being 5 minutes, and then drying the IGBT chip; S12, using plasma surface treatment technology to activate the back side of the dried IGBT chip, the plasma power is 100 W, and the treatment time is 2 minutes; S13, using a spin coating process to uniformly coat a layer of positive photoresist on the back side of the IGBT chip, with a spin coating speed of 4000 rpm and a spin coating time of 40 seconds to form a photoresist coating with a thickness of 1.5 microns; then pre-baking the IGBT chip coated with the positive photoresist on a hot plate at a temperature of 90°C for 2 minutes to remove the solvent in the photoresist.

3. The packaging method of the IGBT chip heat dissipation packaging module according to claim 2, characterized in that: After step S13, the following steps are also included: S14, using ultraviolet lithography technology, aligning and transferring a photomask of a pre-designed microchannel network pattern onto the photoresist layer through an intelligent alignment system; S15, placing the exposed IGBT chip in a developer at 25° C. for development to complete patterning of the IGBT chip; wherein the development time is 60 seconds, and the developer is a 2.38% concentration of tetramethylammonium hydroxide solution; after the development is completed, the surface of the IGBT chip is rinsed with deionized water to remove the residual developer, and then dried in a nitrogen environment; S16, using deep reactive ion etching technology to anisotropically etch the back of the patterned chip substrate; the etching parameters are set as follows: etching gas is SF6 and C4F8, gas flow rates are 130 sccm and 85 sccm respectively, RF power is 800W, etching cycle number is 200 times, each cycle time is 7 seconds, total etching depth is 50 microns, forming a pre-designed microchannel network structure; S17, after the etching process is completed, acetone, anhydrous ethanol and deionized water are used in turn for multi-stage cleaning, followed by drying to obtain the back side of the substrate of the IGBT chip with a microchannel network structure.

4. The packaging method of the IGBT chip heat dissipation packaging module according to claim 1, characterized in that: Step S2 specifically includes: S21, placing the IGBT chip in a plasma cleaning device, and performing surface activation treatment on the inner wall of the microchannel network using argon plasma, with a plasma power of 150 W and a treatment time of 3 minutes; S22, in a chemical vapor deposition system, fixing the IGBT chip on a quartz substrate carrier so that the inner wall of the microchannel network faces the flow direction of the reaction gas; S23, vacuum the CVD reaction chamber of the chemical vapor deposition system to reach a base pressure of 1×10⁻ 4 Pa; high-purity hydrogen and argon were introduced for pre-cleaning, with gas flow rates of 200 sccm and 500 sccm respectively, and the temperature was raised to 800°C for 30 minutes; S24, raising the reaction temperature of the CVD reaction chamber to 1000°C, and introducing carbon source gases methane, hydrogen and argon required for graphene growth under the regulation of the control system, with gas flow rates of 20 sccm for methane, 100 sccm for hydrogen and 500 sccm for argon respectively; S25, starting the graphene deposition process, the deposition time is 15 minutes, and using an online monitoring device to detect the gas composition in the CVD reaction chamber and the graphene growth condition on the inner wall of the microchannel in real time.

5. The packaging method of the IGBT chip heat dissipation packaging module according to claim 4, characterized in that: After step S25, the following steps are also included: S26, after the deposition is completed, the introduction of methane gas is stopped, the flow rates of hydrogen and argon are maintained unchanged, the temperature is gradually lowered to 800° C., and an annealing treatment is performed for 10 minutes; thereafter, the temperature is continued to be lowered, during which the hydrogen is stopped and the introduction of argon is maintained; S27, when the temperature drops below 50°C, the CVD reaction chamber is restored to normal pressure; then the deposited IGBT chip is taken out from the CVD reaction chamber; S28, using a Raman spectrometer to detect the graphene film on the inner wall of the microchannel network to confirm the number of layers and crystal quality of the graphene film, and measuring the thickness of the film by an optical scanning device.

6. The packaging method of the IGBT chip heat dissipation packaging module according to claim 1, characterized in that: Step S3 specifically includes: S31, according to the design parameters of the microchannel network of the IGBT chip, using computer design software to draw a three-dimensional model structure of the microfluid dispenser, the three-dimensional model structure including a coolant inlet, an outlet and an internal microchannel structure; S32, selecting a glass material or a quartz material as a substrate body of the microfluid dispenser, and using laser micromachining technology to process penetrating coolant inlet and outlet holes and a semi-open structure of an internal microchannel on the substrate body; S33, using micromachining technology, engraving a microchannel pattern corresponding to the microchannel network on the surface of the substrate, with a depth of 50 microns and a width of 100 microns, to obtain a microfluidic dispenser; S34, chemically treating the surface of the microfluid dispenser, using a hydrofluoric acid solution to smooth and etch the surface, then thoroughly washing it with deionized water, and drying it for later use.

7. The packaging method of the IGBT chip heat dissipation packaging module according to claim 6, characterized in that: After step S34, the following steps are also included: S35, using plasma surface activation technology, uses plasma to activate the bonding surface of the microfluidic dispenser and the back of the IGBT chip, with a plasma power of 200 W and a treatment time of 2 minutes; S36, aligning the microchannel pattern of the microfluid dispenser with the inlet and outlet of the microchannel network on the back side of the IGBT chip through an alignment device with the assistance of a visual device; S37, using anodic bonding technology, the aligned microfluidic dispenser is bonded to the microchannel network on the back of the IGBT chip; in a vacuum environment, the applied voltage is 1000 V, the temperature is 400 °C, the pressure is 500 N, and the bonding time is 30 minutes; S38, performing a sealing test on the bonded IGBT chip assembly, and performing a leak detection using a helium mass spectrometer leak detector; S39, installing micro joints and sealing gaskets at the inlet and outlet of the coolant of the microfluid dispenser, and fixing the micro joints by epoxy resin glue or welding technology.

8. The packaging method of the IGBT chip heat dissipation packaging module according to claim 1, characterized in that: Step S4 specifically includes: S41, performing surface pretreatment on the front side of the IGBT chip, and performing plasma cleaning on the front side of the chip using a mixed plasma of argon and oxygen; S42: using a dispensing device to uniformly apply a layer of conductive adhesive material with a thickness of 50 microns on the area to be installed on the circuit substrate; at the same time, applying a conductive adhesive material on the corresponding position on the back side of the IGBT chip; the conductive adhesive material is a conductive glue containing silver nanoparticles; S43: Using a mounting device, the pre-processed IGBT chip is placed with the front side facing downward, and the chip electrodes are aligned with the corresponding electrode pad positions on the circuit substrate through a visual recognition system, and the IGBT chip is aligned with the circuit substrate coated with a conductive adhesive material for mounting; S44: placing the mounted components in a hot press curing device and performing hot press curing according to the curing process curve of the conductive adhesive material; the curing temperature is gradually increased to 180°C, the pressure is maintained at 1 MPa, and the curing time is 60 minutes; S45: After solidification is completed, the electrodes of the IGBT chip are interconnected with the circuit on the circuit substrate using laser cladding technology.

9. The packaging method of the IGBT chip heat dissipation packaging module according to claim 1, characterized in that: After step S5, the following steps are also included: S6, performing a coolant circulation test on the packaged IGBT integrated module, checking the sealing performance and fluid circulation of the coolant circulation channel, and performing electrical and thermal performance tests to determine whether the IGBT integrated module meets the design requirements.

10. An IGBT chip heat dissipation packaging module, characterized in that: A packaging method for an IGBT chip heat dissipation packaging module according to any one of claims 1 to 9, wherein the IGBT chip heat dissipation packaging module comprises: An IGBT chip body, wherein a microchannel network is provided on the back side of the IGBT chip body; The heat conduction channel of the graphene film is arranged on the inner wall of the microchannel network; The microfluid distributor matches the microchannel network and has an inlet and an outlet for the coolant. The microfluid distributor is connected to the microchannel network on the back of the IGBT chip through alignment and bonding technology to form a complete coolant circulation channel.

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