IGBT chip heat dissipation packaging module and packaging method

Abstract

The present invention discloses an IGBT chip heat dissipation packaging module and a packaging method, which comprises cleaning and pre-treating the back side of the IGBT chip, etching a microchannel network on the back side, and depositing a graphene film on the inner wall by chemical vapor deposition to form a heat conduction channel; manufacturing a microfluidic dispenser, and connecting the microfluidic dispenser to the back side of the chip by alignment and bonding technology to form a complete coolant circulation channel; fixing the front side of the IGBT chip on a circuit substrate by using a conductive adhesive material, and interconnecting with the circuit on the circuit substrate; packaging the IGBT chip and the microfluidic dispenser by using a packaging material to obtain an IGBT integrated module; and innovatively integrating a microfluidic heat dissipation system and a high-efficiency heat conduction channel based on the structural characteristics of the IGBT chip, thereby significantly improving the heat dissipation effect and working stability of the IGBT chip and extending the service life of the chip.

Description

Technical Field

[0001] The present invention relates to the technical field of chip packaging, and in particular 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, high-frequency industrial applications such as electric vehicles, renewable energy generation systems, industrial motor drives, and power transmission and distribution systems. These applications place stringent demands on IGBT chips for high current, high voltage, and high-speed switching, resulting in significant heat generation during chip operation. Failure to dissipate heat promptly and effectively can severely impact chip performance and reliability, potentially leading to reduced efficiency, unstable operation, and even thermal failure. Therefore, improving the heat dissipation capabilities of IGBT chips to ensure stable operation under high power density and high frequency conditions has become a key focus in the industry.

[0003] In existing chip heat dissipation integration technologies, heat sinks are usually attached to the back of the chip, high thermal conductivity interface materials are used, or the chip is encapsulated on a substrate with heat dissipation function to assist in the conduction and dissipation of heat. However, these traditional heat dissipation methods have certain limitations. For example, the thermal conductivity efficiency of heat sinks and thermal conductive interface materials is limited, and they cannot meet the rapid heat dissipation requirements of high-power IGBT chips. Although encapsulating the chip on a heat dissipation substrate improves the heat dissipation capacity to a certain extent, the heat needs to be transferred through multiple layers of interfaces, resulting in large thermal resistance and poor heat dissipation effect. In addition, existing integration technologies make it difficult to achieve a refined heat dissipation channel layout inside the chip, and it is impossible to effectively control the heat density in different areas of the chip. These shortcomings lead to heat accumulation inside the chip, forming hot spots, which seriously affect the working stability and life of the IGBT chip, and limit its 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 existing technology to solve the problem that it cannot meet the high heat dissipation performance requirements of the chip. Summary of the Invention

[0005] The object 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 object, the present invention adopts the following technical solutions:

[0007] A packaging method for an IGBT chip heat dissipation packaging module, comprising:

[0008] 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 etching technology;

[0009] S2, depositing a graphene film on the inner wall of the microchannel network using a chemical vapor deposition method to form a heat conduction channel;

[0010] S3, manufacturing a microfluidic dispenser that matches the microchannel network, and connecting the microfluidic dispenser to the microchannel network on the back 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;

[0011] S4, fixing the IGBT chip on a circuit substrate using a conductive adhesive material on the front surface of the IGBT chip, and interconnecting the electrodes of the IGBT chip with the circuit on the circuit substrate using a laser cladding technique;

[0012] S5, packaging the IGBT chip and the microfluidic dispenser using a packaging material to obtain an IGBT integrated module.

[0013] Optionally, step S1 specifically includes:

[0014] 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, with each cleaning time being 5 minutes, and then drying the IGBT chip;

[0015] S12, using plasma surface treatment technology to activate the back side of the dried IGBT chip, with a plasma power of 100 W and a treatment time of 2 minutes;

[0016] S13, using a spin coating process to uniformly coat a layer of positive photoresist on the back side of the IGBT chip at a spin coating 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.

[0017] Optionally, after step S13, the following steps are further included:

[0018] S14, using ultraviolet lithography technology, through an intelligent alignment system, aligning and transferring a photomask with a pre-designed microchannel network pattern onto the photoresist layer;

[0019] 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 development is completed, the surface of the IGBT chip is rinsed with deionized water to remove residual developer, and then blown dry under a nitrogen environment;

[0020] In step S16, deep reactive ion etching (DRI) was used to anisotropically etch the backside of the patterned chip substrate. The etching parameters were set as follows: SF6 and C4F8 etching gases with gas flow rates of 130 sccm and 85 sccm, respectively; RF power of 800 W; 200 etching cycles with a cycle time of 7 seconds per cycle; and a total etching depth of 50 μm, forming a pre-designed microchannel network structure.

[0021] S17, after the etching process is completed, acetone, anhydrous ethanol and deionized water are used in sequence for multi-stage cleaning, and then drying is performed to obtain the back side of the substrate of the IGBT chip with a microchannel network structure.

[0022] Optionally, step S2 specifically includes:

[0023] 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;

[0024] S22, in a chemical vapor deposition system, fixing the IGBT chip on a quartz substrate carrier, with the inner wall of the microchannel network facing the flow direction of the reaction gas;

[0025] S23: The CVD reaction chamber of the chemical vapor deposition system is vacuum-evacuated to 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;

[0026] S24, raising the reaction temperature of the CVD reaction chamber to 1000°C, and introducing methane, hydrogen, and argon, the carbon source gases 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;

[0027] 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.

[0028] Optionally, after step S25, the following steps are further included:

[0029] S26, after the deposition is completed, the 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; then the temperature is continued to be lowered, during which the hydrogen gas is stopped and the argon gas is kept flowing;

[0030] S27, when the temperature drops below 50°C, the CVD reaction chamber is restored to normal pressure; then the deposited IGBT chip is removed from the CVD reaction chamber;

[0031] 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.

[0032] Optionally, step S3 specifically includes:

[0033] S31, using computer design software to draw a three-dimensional model structure of a microfluidic distributor according to the design parameters of the microchannel network of the IGBT chip, where the three-dimensional model structure includes a coolant inlet, an outlet, and an internal microchannel structure;

[0034] S32, selecting a glass material or a quartz material as a substrate of the microfluidic dispenser, and using laser micromachining technology to machine penetrating coolant inlet and outlet holes and a semi-open structure of an internal microchannel on the substrate;

[0035] 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;

[0036] S34, performing chemical treatment on the surface of the microfluidic 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.

[0037] Optionally, after step S34, the following steps are further included:

[0038] S35, using plasma surface activation technology, uses 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.

[0039] S36, using an alignment device and with the assistance of a visual device, aligning the microchannel pattern of the microfluidic dispenser with the inlet and outlet of the microchannel network on the back side of the IGBT chip;

[0040] 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.

[0041] S38, performing a sealing test on the bonded IGBT chip assembly, using a helium mass spectrometer leak detector for leak detection;

[0042] S39, installing micro joints and sealing gaskets at the inlet and outlet of the coolant of the microfluidic dispenser, and fixing the micro joints by using epoxy resin glue or welding technology.

[0043] Optionally, step S4 specifically includes:

[0044] 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;

[0045] S42: Using a dispensing device, evenly apply a layer of conductive adhesive material with a thickness of 50 microns on the area to be mounted on the circuit substrate; at the same time, apply conductive adhesive material to the corresponding position on the back side of the IGBT chip; the conductive adhesive material is a conductive glue containing silver nanoparticles;

[0046] S43: Using the placement equipment, the pre-processed IGBT chip is placed face down, and the chip electrodes are aligned with the corresponding electrode pads on the circuit substrate using a visual recognition system. The IGBT chip is then aligned with the circuit substrate coated with a conductive adhesive material for placement.

[0047] S44: Place the mounted components in a hot press curing device and perform 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;

[0048] S45: After solidification is completed, the electrodes of the IGBT chip are interconnected with the circuit on the circuit substrate using laser cladding technology.

[0049] Optionally, after step S5, the following steps are further included:

[0050] S6, performing a coolant circulation test on the packaged IGBT integrated module to check 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.

[0051] The present invention further provides an IGBT chip heat dissipation packaging module, including the packaging method of the IGBT chip heat dissipation packaging module as described above, wherein the IGBT chip heat dissipation packaging module includes:

[0052] An IGBT chip body, wherein a microchannel network is provided on the back side of the IGBT chip body;

[0053] The heat conduction channel of the graphene film is arranged on the inner wall of the microchannel network;

[0054] The microfluidic distributor matches the microchannel network and has a coolant inlet and outlet. 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.

[0055] Compared with the existing technology, the present invention has the following beneficial effects: first, the back of the IGBT chip is cleaned and pre-treated, and then a pre-designed microchannel network is etched on the back of the chip substrate using etching technology. A high-thermal-conductivity graphene film is deposited on the inner wall of the microchannel network using chemical vapor deposition to form an efficient heat conduction channel, thereby enhancing the thermal conductivity of the microchannel; a microfluidic distributor matching the microchannel network is manufactured, and the microfluidic distributor is connected to the microchannel network on the back of the chip through alignment and bonding technology to form a complete coolant circulation channel. The microfluidic distributor has a coolant inlet and outlet to ensure that the coolant can circulate effectively; in On the front side of the IGBT chip, a conductive adhesive material is used to fix the IGBT chip on the circuit substrate, and laser cladding technology is used to interconnect the electrodes of the IGBT chip with the circuit on the circuit substrate, achieving high reliability of the electrical connection; the IGBT chip and the microfluidic dispenser are packaged with packaging materials, and finally an IGBT integrated module with good heat dissipation performance and mechanical strength is obtained; this method innovatively integrates the microfluidic heat dissipation system and the efficient heat conduction channel based on 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 is suitable for high-power, high-frequency industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0057] The structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not intended to limit the conditions under which the present invention can be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportional relationships, or adjustments in size should still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and objectives that can be achieved by the present invention.

[0058] Figure 1 This is a flow chart of a packaging method for an IGBT chip heat dissipation packaging module according to the first embodiment;

[0059] Figure 2 This is a second flow chart of the packaging method of the IGBT chip heat dissipation packaging module of the first embodiment. DETAILED DESCRIPTION

[0060] In order to make the purpose, features, and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0061] In the description of the present invention, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They are not intended to indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally located component.

[0062] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0063] Example 1:

[0064] Combine Figures 1 to 2 As shown, an embodiment of the present invention provides a packaging method for an IGBT chip heat dissipation packaging module, comprising:

[0065] 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 etching technology;

[0066] Thorough cleaning and pretreatment of the backside of the IGBT chip are crucial. This cleaning process removes organic contaminants, particulate matter, and oxide layers, ensuring the effectiveness of subsequent processes. Subsequently, precise etching techniques (such as deep reactive ion etching (DRIE)) are used to create a pre-designed microchannel network on the backside of the chip substrate. This microchannel network enhances the chip's heat dissipation capabilities, enabling rapid and efficient heat dissipation during high-power operation, improving chip performance and reliability.

[0067] S2, depositing a graphene film on the inner wall of the microchannel network using a chemical vapor deposition method to form a heat conduction channel;

[0068] Chemical vapor deposition (CVD) is used to deposit a high-quality graphene film on the inner walls of the microchannel network. Graphene has extremely high thermal conductivity, significantly improving heat transfer within the microchannels. By depositing the graphene film on the inner walls of the microchannels, an efficient heat conduction channel is formed, allowing heat generated by the chip to 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. Furthermore, the deposition of the graphene film must be closely aligned with the microchannel structure to ensure the continuity and effectiveness of the heat conduction channel.

[0069] S3, manufacturing a microfluidic dispenser that matches the microchannel network, and connecting the microfluidic dispenser to the microchannel network on the back 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;

[0070] Design and manufacture 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 microchannels. Then, use precision machining technology to manufacture the microfluidic dispenser. 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 adhesive 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 remove the heat generated by the chip during operation.

[0071] S4, fixing the IGBT chip on a circuit substrate using a conductive adhesive material on the front surface of the IGBT chip, and interconnecting the electrodes of the IGBT chip with the circuit on the circuit substrate using a laser cladding technique;

[0072] Mounting the IGBT chip on the circuit substrate is a critical step. First, a conductive adhesive (such as silver-containing conductive glue) is applied to the front of the chip and the corresponding position on the circuit substrate to ensure mechanical fixation and reliable electrical connection. The chip is then accurately mounted on the circuit substrate, and the conductive adhesive is cured through processes such as heat pressing to form a secure connection. Subsequently, laser cladding technology is used to interconnect the IGBT chip's electrodes with the circuitry on the circuit substrate. Laser cladding technology offers high precision and a low heat-affected zone, resulting in a low-resistance, highly reliable electrical connection.

[0073] S5, packaging the IGBT chip and the microfluidic dispenser using a packaging material to obtain an IGBT integrated module.

[0074] The assembled IGBT chip and microfluidic dispenser are encapsulated as a whole. The encapsulation material is typically selected from a material with excellent insulation, thermal conductivity, and mechanical protection (such as epoxy resin or a specially formulated encapsulant). The encapsulation process must be performed in a clean environment to ensure that no impurities or bubbles are introduced into the encapsulation material. The purpose of the encapsulation is to protect the chip and microfluidic dispenser from external environmental influences such as humidity, dust, and mechanical stress, while also providing additional mechanical strength and a heat dissipation path.

[0075] The working principle of the present invention is as follows: first, the back of the IGBT chip is cleaned and pre-treated, and then a pre-designed microchannel network is etched on the back of the chip substrate using etching technology. A high-thermal-conductivity graphene film is deposited on the inner wall of the microchannel network using chemical vapor deposition to form an efficient heat conduction channel, thereby enhancing the thermal conductivity of the microchannel; a microfluidic distributor matching the microchannel network is manufactured, and the microfluidic distributor is connected to the microchannel network on the back of the chip through alignment and bonding technology to form a complete coolant circulation channel. The microfluidic distributor has a coolant inlet and outlet to ensure that the coolant can circulate effectively; in the IGBT core The front side of the chip is fixed to the circuit substrate using conductive adhesive material, and the electrodes of the IGBT chip are interconnected with the circuit on the circuit substrate using laser cladding technology, thereby achieving high reliability of the electrical connection; the IGBT chip and the microfluidic dispenser are packaged using packaging materials, and finally an IGBT integrated module with good heat dissipation performance and mechanical strength is obtained; this method innovatively integrates the microfluidic heat dissipation system and the efficient heat conduction channel based on 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 is suitable for high-power, high-frequency industrial applications.

[0076] In this embodiment, it is specifically explained that step S1 specifically includes:

[0077] 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, with each cleaning time being 5 minutes, and then drying the IGBT chip;

[0078] Cleaning is performed to remove organic pollutants, particulate matter, and oxide layers on the back of the chip. After cleaning, the chip is placed in a clean, dry environment and dried in an oven at 100°C for 10 minutes to ensure that no moisture remains on the surface.

[0079] S12, plasma surface treatment technology is used to activate the back side of the dried IGBT chip. The plasma power is 100 W and the treatment time is 2 minutes. This is to improve the adhesion of the photoresist in the subsequent process.

[0080] S13, using a spin coating process to uniformly coat a layer of positive photoresist on the back side of the IGBT chip at a spin coating 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.

[0081] The S14 uses UV lithography technology and an intelligent alignment system to align and transfer the pre-designed microchannel network pattern photomask onto the photoresist layer; the exposure energy is 150 mJ / cm² and the exposure time is 10 seconds, ensuring high resolution and accuracy of the microchannel pattern.

[0082] S15, placing the exposed IGBT chip in a developer at 25°C for development to complete the 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 blown dry in a nitrogen environment.

[0083] In order to enhance the etching resistance of the microchannel pattern, the developed IGBT chip was placed on a hot plate at 120°C for post-baking for 5 minutes to fully cross-link the photoresist and enhance its corrosion resistance.

[0084] S16 uses deep reactive ion etching technology to perform anisotropic etching on the back side of the patterned chip substrate; the etching parameters are set as follows: SF6 and C4F8 etching gases, gas flow rates of 130 sccm and 85 sccm respectively, RF power of 800 W, etching cycles of 200 times, each cycle time of 7 seconds, and a total etching depth of 50 microns, forming a pre-designed microchannel network structure.

[0085] S17, after the etching process is completed, acetone, anhydrous ethanol and deionized water are used in sequence for multi-stage cleaning, and then drying is performed to obtain the back side of the substrate of the IGBT chip with a microchannel network structure.

[0086] Specifically, use an organic solvent (such as acetone) to completely remove the residual photoresist on the back of the IGBT chip; then, use deionized water and anhydrous ethanol to clean the chip surface in sequence, and finally, blow dry with nitrogen in a clean and dry environment or place it in an oven at 100°C for 5 minutes to obtain the back of the IGBT chip substrate with a microchannel network structure.

[0087] Use optical scanning equipment to inspect the etched microchannel network structure to confirm that the size, morphology and position of the microchannel meet the preset design requirements; if defects are found, record them and make corresponding process adjustments.

[0088] In this embodiment, it is specifically described that step S2 specifically includes:

[0089] S21, placing the IGBT chip in a plasma cleaning device, and using argon plasma to perform surface activation treatment on the inner wall of the microchannel network, with a plasma power of 150 W and a treatment time of 3 minutes; to remove residual organic matter and oxide layer on the inner wall of the microchannel and enhance the adhesion of the graphene film.

[0090] S22, in a chemical vapor deposition system, fix the IGBT chip on a quartz substrate carrier so that the inner wall of the microchannel network faces the direction of reaction gas flow; use a robotic arm to automatically load the chip into the CVD reaction chamber to avoid contamination introduced by manual operation.

[0091] S23: The CVD reaction chamber of the chemical vapor deposition system is vacuum-evacuated to 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 to further remove surface impurities on the inner wall of the microchannel.

[0092] S24, raising the reaction temperature of the CVD reaction chamber to 1000°C. Under the regulation of the control system, the carbon source gases methane, hydrogen, and argon required for graphene growth are introduced, with gas flow rates of 20 sccm for methane, 100 sccm for hydrogen, and 500 sccm for argon, respectively; and maintaining the pressure of the CVD reaction chamber at 500 Pa.

[0093] S25, starting the graphene deposition process, the deposition time is 15 minutes, using an online monitoring device to detect the gas composition in the CVD reaction chamber and the graphene growth on the inner wall of the microchannel in real time to ensure the continuity and high quality of the graphene film.

[0094] After deposition is complete, the methane flow is stopped, the hydrogen and argon flows are maintained constant, and the temperature is gradually lowered to 800°C for 10 minutes of annealing to improve the crystal quality and thermal conductivity of the graphene film. The cooling process is then continued, during which the hydrogen flow is stopped and the argon flow is maintained to prevent oxidation of the graphene film during the cooling process. During the cooling process, the intelligent control system monitors temperature and atmosphere changes in real time to ensure the stability of the cooling process.

[0095] S27, when the temperature drops below 50°C, the CVD reaction chamber is restored to normal pressure; then the deposited IGBT chip is removed from the CVD reaction chamber;

[0096] A robotic arm is used to remove the deposited IGBT chip from the reaction chamber and store 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.

[0097] 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; ensuring that the thickness is uniform between 1-2 nanometers to meet the requirements of high thermal conductivity.

[0098] For chips whose test 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, based on the feedback information, and repeats steps S24 to S28 until the quality of the graphene film reaches the preset standard.

[0099] The IGBT chips that meet the quality requirements are subjected to surface protection treatment, and a peelable protective film is coated at the entrance and exit of the microchannel network to prevent impurities from entering the microchannels in subsequent processes and maintain the integrity of the graphene film.

[0100] In this embodiment, it is specifically explained that step S3 specifically includes:

[0101] S31, based on the design parameters of the microchannel network of the IGBT chip, use computer design software to draw a three-dimensional model structure of the microfluidic distributor, where the three-dimensional model structure includes a coolant inlet, outlet, and internal microchannel structure; ensure that the inlet and outlet positions and dimensions are precisely matched with the microchannel network.

[0102] S32, selecting a glass material (such as borosilicate glass) or quartz material with high transparency, high temperature resistance, and high chemical corrosion resistance as the substrate of the microfluidic dispenser, and using laser micromachining technology to machine penetrating coolant inlet and outlet holes and a semi-open structure of the internal microchannel on the substrate;

[0103] In order to meet the requirements of heat dissipation performance and reliability, ultra-precision processing technology (such as ultraviolet laser micromachining or precision grinding) is used to process penetrating coolant inlet and outlet holes and a semi-open structure of internal microchannels on the substrate.

[0104] S33, using micromachining technology, a microchannel pattern corresponding to the microchannel network is engraved on the surface of the substrate 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 microns, ensuring the smoothness and dimensional accuracy of the channel.

[0105] S34, performing chemical treatment on the surface of the microfluidic 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.

[0106] To reduce microscopic defects on the surface of the microchannel and improve fluid flow performance; then, thoroughly rinse with deionized water and dry for use.

[0107] S35 uses plasma surface activation technology to activate the bonding surfaces of the microfluidic dispenser and the back of the IGBT chip using plasma. The plasma power is 200 W and the treatment time is 2 minutes to enhance the bonding force between the two components.

[0108] S36, through a positioning device (such as a six-axis precision alignment platform), with the assistance of visual equipment, align the microchannel pattern of the microfluidic dispenser with the inlet and outlet of the microchannel network on the back of the IGBT chip; the positioning error is controlled within ±2 microns to ensure seamless connection of the channel.

[0109] S37 uses anodic bonding technology to bond the aligned microfluidic dispenser 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. This achieves a strong bond between glass and silicon, forming a closed coolant circulation channel.

[0110] After bonding is completed, gradually cool to room temperature to prevent cracks in the bonding interface caused by thermal stress caused by a sudden drop in temperature; maintain the voltage during the cooling process until the temperature drops below 100°C.

[0111] S38, perform sealing test on the bonded IGBT chip assembly, and use a helium mass spectrometer leak detector to detect leaks; ensure that the sealing performance of the microfluidic channel meets the requirements.

[0112] Components that pass the sealing test are tested for coolant flow performance. A precise micro-flow pump is connected to introduce coolant (such as deionized water or special coolant) at a predetermined flow rate. Micro Particle Image Velocimetry (μPIV) technology is used to observe the flow state of the coolant in the microchannel network to ensure that the flow channel is unobstructed and the flow is uniform.

[0113] S39, installing micro connectors and sealing washers at the coolant inlet and outlet of the microfluidic dispenser, and fixing the micro connectors with epoxy resin glue or welding technology to ensure the reliability and sealing of the coolant pipeline connection.

[0114] In this embodiment, it is specifically explained that step S4 specifically includes:

[0115] 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; the plasma power is 150 W, and the processing time is 2 minutes, so as to remove organic pollutants and an oxide layer on the surface, enhance the adhesion of the conductive adhesive material, and activate the chip surface.

[0116] S42: Using a dispensing device, evenly 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, apply conductive adhesive material on the corresponding position on the back of the IGBT chip; the conductive adhesive material is a conductive glue containing silver nanoparticles.

[0117] S43: Use the mounting equipment to place the pre-processed IGBT chip face down, and use the visual recognition system to align the chip electrodes with the corresponding electrode pads on the circuit substrate. Then, align the IGBT chip and the circuit substrate coated with conductive adhesive material for mounting. The alignment accuracy is controlled within ±5 microns. During the mounting process, a constant mounting pressure (such as 500kPa) is applied to ensure full contact between the chip and the substrate and eliminate bubbles in the adhesive layer.

[0118] S44: Place the mounted components in a hot press curing device and perform 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; during this process, an intelligent temperature and pressure control system is used to accurately adjust the curing parameters to ensure that the conductive adhesive material is fully cured and form a stable mechanical and electrical connection.

[0119] S45: After solidification is completed, the electrodes of the IGBT chip are interconnected with the circuit on the circuit substrate using laser cladding technology.

[0120] Specifically, high-precision laser cladding equipment is used, and high-purity metal powder (such as silver powder or copper powder) with a diameter of 20 microns is selected as the cladding material; under a protective atmosphere (such as nitrogen), the laser power is set to 200 W and the scanning speed is set to 10 mm / s, and the cladding material is clad on the connection area between the chip electrode and the substrate circuit; through the metallurgical bonding of the cladding layer, a low-resistance, high-reliability electrical interconnection is formed, thereby improving the electrical performance and long-term stability of the module.

[0121] In this embodiment, it is further explained that after step S5, the following steps are further included:

[0122] S6, performing a coolant circulation test on the packaged IGBT integrated module to check 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.

[0123] The packaged IGBT integrated module is thoroughly tested and verified. First, a coolant circulation test is performed. By passing coolant, the sealing and fluid circulation of the microchannel network and microfluidic distributor are checked to ensure there are no leaks or blockages. Measuring equipment is used to monitor the flow rate, pressure, and temperature changes of the coolant to verify the performance of the cooling system. Subsequently, an electrical performance test is performed to measure the switching characteristics, on-resistance, and insulation performance of the IGBT module to ensure that the electrical performance meets the specifications. Next, a thermal performance test is performed to evaluate the module's heat dissipation capacity and temperature stability under simulated actual operating conditions. Comprehensive analysis of the test data is used to 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 causes need to be analyzed and corresponding improvements and adjustments need to be made.

[0124] Example 2:

[0125] The present invention further provides an IGBT chip heat dissipation packaging module, including the packaging method of the IGBT chip heat dissipation packaging module as described above, wherein the IGBT chip heat dissipation packaging module includes:

[0126] An IGBT chip body is provided with a microchannel network on the back side of the IGBT chip body; a pre-designed microchannel network is etched using etching technology, and these microchannels are used to enhance the heat dissipation capability of the chip.

[0127] The heat conduction channel of the graphene film is arranged on the inner wall of the microchannel network; the graphene film is deposited by chemical vapor deposition. Graphene has excellent thermal conductivity, forming an efficient heat conduction channel and improving the heat dissipation efficiency of the chip.

[0128] The microfluidic distributor matches the microchannel network and has a coolant inlet and outlet. 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, achieving effective cooling of the chip.

[0129] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions 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 etching technology; The etching process is as follows: Deep reactive ion etching (DRI) is used to etch a microchannel network on the back of the IGBT chip. The etching parameters are SF6 and C4F8 gas flow rates of 130 sccm and 85 sccm, respectively, RF power of 800W, 200 etching cycles, each cycle time of 7 seconds, and a total etching depth of 50 microns. S2, using chemical vapor deposition to deposit a graphene film on the inner wall of the microchannel network to form a heat conduction channel; specifically, methane, hydrogen and argon are introduced into the CVD reaction chamber, with gas flow rates of 20 sccm, 100 sccm and 500 sccm respectively, the reaction temperature is 1000°C, and the deposition time is 15 minutes; 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; then the cooling treatment is continued, during which the hydrogen gas is stopped and the argon gas is kept introduced; when the temperature drops below 50°C, the CVD reaction chamber is restored to normal pressure; then the deposited IGBT chip is removed from the CVD reaction chamber; a Raman spectrometer is used 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 the thickness of the film is measured by an optical scanning device; S3, making a microfluidic dispenser that matches the microchannel network, and connecting the microfluidic dispenser to the microchannel network on the back of the chip through alignment and bonding technology to form a complete coolant circulation channel; specifically: S31, using computer design software to draw a three-dimensional model structure of a microfluidic distributor according to the design parameters of the microchannel network of the IGBT chip, where the three-dimensional model structure includes a coolant inlet, an outlet, and an internal microchannel structure; S32, selecting a glass material or a quartz material as a substrate of the microfluidic dispenser, and using laser micromachining technology to machine penetrating coolant inlet and outlet holes and a semi-open structure of an internal microchannel on the substrate; S33, using micromachining technology to carve a microchannel pattern corresponding to the microchannel network on the surface of the substrate to obtain a microfluidic dispenser; S34, chemically treating the surface of the microfluidic dispenser by using a hydrofluoric acid solution to smooth and etch the surface, then thoroughly washing it with deionized water and drying it for later use; S35, using plasma surface activation technology, uses 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, using an alignment device and with the assistance of a visual device, aligning the microchannel pattern of the microfluidic dispenser with the inlet and outlet of the microchannel network on the back side of the IGBT chip; 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, using a helium mass spectrometer leak detector for leak detection; S39, installing micro-connectors and sealing gaskets at the coolant inlet and outlet of the microfluidic dispenser, and fixing the micro-connectors using epoxy resin glue or welding technology; S4, fixing the IGBT chip on the circuit substrate using a conductive adhesive material on the front side of the IGBT chip. Specifically, a conductive adhesive material containing silver nanoparticles is applied to corresponding positions on the circuit substrate and the front side of the chip to a thickness of 50 microns. The chip is mounted using a placement device and cured using a hot press curing device at a curing temperature of 180°C, a pressure of 1 MPa, and a curing time of 60 minutes. Laser cladding technology is used to interconnect the electrodes of the IGBT chip with the circuits on the circuit substrate. S5, packaging the IGBT chip and the microfluidic dispenser using a packaging material 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, with 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, with a plasma power of 100 W and a treatment time of 2 minutes; S13, using a spin coating process to uniformly coat a layer of positive photoresist on the back side of the IGBT chip at a spin coating 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.

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, through an intelligent alignment system, aligning and transferring a photomask with a pre-designed microchannel network pattern onto the photoresist layer; 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 development is completed, the surface of the IGBT chip is rinsed with deionized water to remove residual developer, and then blown dry under a nitrogen environment; S16, using deep reactive ion etching technology to anisotropically etch the back side of the patterned chip substrate; S17, after the etching process is completed, acetone, anhydrous ethanol and deionized water are used in sequence for multi-stage cleaning, and then drying is performed 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, with the inner wall of the microchannel network facing the flow direction of the reaction gas; S23: The CVD reaction chamber of the chemical vapor deposition system is vacuum-evacuated to 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 methane, hydrogen, and argon, carbon source gases required for graphene growth, under the regulation of the control system; S25, starting the graphene deposition process, using an online monitoring device to detect in real time the gas composition in the CVD reaction chamber and the graphene growth condition on the inner wall of the microchannel.

5. 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, evenly apply a layer of conductive adhesive material with a thickness of 50 microns on the area to be mounted on the circuit substrate; at the same time, apply conductive adhesive material to the corresponding position on the back side of the IGBT chip; the conductive adhesive material is a conductive glue containing silver nanoparticles; S43: Using the placement equipment, the pre-processed IGBT chip is placed face down, and the chip electrodes are aligned with the corresponding electrode pads on the circuit substrate using a visual recognition system. The IGBT chip is then aligned with the circuit substrate coated with a conductive adhesive material for placement. 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, with the curing temperature gradually increasing to 180°C; S45: After solidification is completed, the electrodes of the IGBT chip are interconnected with the circuit on the circuit substrate using laser cladding technology.

6. 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 to check 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.

7. An IGBT chip heat dissipation packaging module, characterized in that: The IGBT chip heat dissipation packaging module is prepared by the packaging method according to any one of claims 1 to 6, and 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 microfluidic distributor matches the microchannel network and has a coolant inlet and outlet. 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.

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