Power substrate manufacturing method, power substrate and power module

Abstract

The invention provides a power substrate manufacturing method, a power substrate and a power module, and the method comprises the steps: sequentially carrying out the alkali washing, acid pickling, oxidation and roughening of a first blanking metal plate, and forming a heat dissipation bottom plate; sequentially cleaning and passivating the second blanking metal plate to form an electrical metal layer; the heat dissipation bottom plate, the given insulating layer and the electrical metal layer are stacked and then placed in a vacuum hot pressing furnace to be processed, and an integrated insulating metal substrate is formed; and etching a required power circuit pattern on the integrated insulating metal substrate to obtain the power substrate. According to the power substrate manufactured by using the method provided by the invention, through the treatment processes of roughening, passivation and the like, the bonding strength among the layers is higher, the cracking wind direction of the power substrate in the application process is greatly reduced, and the reliability and the safety of a power module applying the power substrate are improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor packaging technology, and in particular to a method for manufacturing a power substrate, a power substrate, and a power module. Background Technology

[0002] In the field of power semiconductor packaging, heat dissipation performance and cost-effectiveness are two core challenges for power modules. Existing power modules typically use traditional DBC ceramic substrates (direct copper-clad ceramic substrates). Although they perform well in high-power applications, their complex stacking structure leads to high thermal resistance, and the manufacturing process is complex and costly. For example, 34mm or 62mm power modules typically use an aluminum base plate + DBC ceramic substrate with a bridge electrical topology, requiring at least four discrete DBC ceramic substrates soldered to the aluminum base plate. However, this structure requires at least three soldering steps (chip soldering to the DBC, DBC soldering to the aluminum base plate, and power electrode soldering to the DBC) and two wire bonding steps during manufacturing, making the process cumbersome and costly.

[0003] To reduce costs, decrease product thermal resistance, optimize product processes and structures, reduce welding voids, improve heat dissipation, and enhance operational reliability, existing technologies provide a manufacturing process for Integrated Metal Substrate (IMS). Referring to patent CN201810637631.2, "A Heat Dissipation Substrate with Embedded Copper-Based IMS and Its Preparation Method," this process discloses the use of hot pressing technology. Under high temperature and vacuum conditions, a copper plating (electric metal layer), a thermally conductive insulating adhesive layer (insulating layer), and a heat dissipation base plate are pressed together under high pressure to form an integrated metal substrate. However, due to cost considerations for industrial applications, the materials of the heat dissipation base plate and the electrical metal layer often differ. This results in insufficient pressure bonding between the electrical metal layer, the insulating layer, and the heat dissipation base plate after high-pressure pressing. Consequently, when the integrated metal substrate is used in practical applications (such as high-temperature chip welding or power modules operating in high-temperature environments for extended periods), it is prone to cracking and delamination, severely impacting the reliability and safety of the power module. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide at least one method for manufacturing a power substrate, a power substrate, and a power module. The power substrate manufactured by the method provided in this application, through roughening, passivation and other processes, has a stronger bonding strength between the layers, which greatly reduces the cracking risk of the power substrate during application and improves the reliability and safety of the power module using the power substrate.

[0005] This application mainly includes the following aspects: In a first aspect, embodiments of this application provide a method for manufacturing a power substrate, the method comprising: punching a first metal sheet and a second metal sheet according to the size requirements of a power module to obtain a first punched metal sheet and a second punched metal sheet; subjecting the first punched metal sheet to alkali washing, acid washing, oxidation and roughening treatment in sequence to form a heat dissipation base plate; subjecting the second punched metal sheet to cleaning and passivation treatment in sequence to form an electrical metal layer; stacking the heat dissipation base plate, a given insulating layer and the electrical metal layer and then placing them in a vacuum hot press furnace for processing to form an integrated insulating metal substrate; etching the required power circuit pattern on the integrated insulating metal substrate to obtain the power substrate.

[0006] In one possible implementation, the first punched sheet metal is subjected to alkali washing, acid washing, oxidation, and roughening treatments in sequence, including: placing the first punched sheet metal in an alkaline solvent at 50℃-70℃ and performing a first ultrasonic cleaning at a frequency of 20kHz-25kHz for 5min-10min; then, cleaning the first punched sheet metal after the first ultrasonic cleaning in 99.9% anhydrous alcohol for 3min-5min; and finally, baking the treated first punched sheet metal in a hot air circulating oven at 100℃-120℃ for 5min-10min to obtain the alkali-washed first punched sheet metal; and then... The first punched metal sheet is placed in an acidic solvent at 35℃-65℃ and ultrasonically cleaned for 3-5 minutes at a frequency of 20kHz-25kHz. After the second ultrasonic cleaning, the first punched metal sheet is cleaned in 99.9% anhydrous alcohol for 3-5 minutes. The treated first punched metal sheet is then baked in a hot air circulating oven at 100℃-120℃ for 5-10 minutes to obtain the pickled first punched metal sheet. The pickled first punched metal sheet is then oxidized to obtain the oxidized first punched metal sheet. The oxidized first punched metal sheet is then roughened to form a heat dissipation base plate.

[0007] In one possible implementation, the oxidation treatment includes: placing the pickled first stamped sheet metal in a fixture and feeding it into a high-temperature furnace tube, heating the high-temperature furnace tube to 100℃-120℃ at a rate of 5℃ / min-10℃ / min; introducing an inert gas into the high-temperature furnace tube to maintain a stable and uniform temperature; continuously introducing high-purity oxygen into the high-temperature furnace tube at a rate of 1L / min-10L / min for 30min-60min to form an oxide layer on the surface of the first stamped sheet metal; cooling the temperature inside the high-temperature furnace tube to room temperature at a rate of 3℃ / min-5℃ / min; removing the oxidized first stamped sheet metal from the high-temperature furnace tube and placing it in 99.9% anhydrous alcohol, and performing a third ultrasonic cleaning at a frequency of 5kHz-15kHz for 5min-10min; and placing the first stamped sheet metal after the third ultrasonic cleaning in a hot air circulating oven at 50℃-75℃ and baking it for 10min-15min.

[0008] In one possible implementation, the roughening process includes: forming 50μm~100μm alumina sand particles on the surface of the first punched sheet metal after oxidation treatment by sandblasting to obtain a heat dissipation base plate.

[0009] In one possible implementation, the second stamped sheet metal is subjected to sequential cleaning and passivation treatments, including: placing the second stamped sheet metal in 99.9% anhydrous alcohol and performing a first ultrasonic cleaning at a frequency of 20kHz-25kHz for 6-8 minutes; placing the second stamped sheet metal after the first ultrasonic cleaning in a hot air circulating oven at 100℃-120℃ for a first drying treatment of 5-10 minutes; immersing the second stamped sheet metal after the first drying treatment in a benzotriazole solution with a concentration of 85±10% and a temperature of 40±2℃ for 3-5 minutes to form a passivation layer of 1μm-3μm (micrometers) on the surface of the second stamped sheet metal; placing the passivated second stamped sheet metal in 99.9% anhydrous alcohol and performing a second ultrasonic cleaning at a frequency of 20kHz-25kHz for 15-20 minutes; and placing the second stamped sheet metal after the second ultrasonic cleaning in a hot air circulating oven at 100℃-120℃ for a second drying treatment of 5-10 minutes.

[0010] In one possible implementation, the given insulating layer comprises epoxy resin, 10%-35% by mass of toughening agent, 10%-20% by mass of high-temperature curing agent, 3%-8% by mass of nanoparticles with a particle size <50nm, and 1%-2% by mass of silane coupling agent.

[0011] In one possible implementation, the given insulating layer is formed by: stirring a toughening agent and epoxy resin in a container at 70°C for 3 hours to form a homogeneous prepolymer, and then cooling the prepolymer to 50°C by natural cooling; adding a high-temperature curing agent, nanoparticles, and a silane coupling agent to the container, stirring the prepolymer until homogeneous and degassing to obtain the insulating layer to be treated; and placing the insulating layer to be treated in a vacuum oven for curing to obtain the given insulating layer; wherein the curing process includes: heating the vacuum chamber of the vacuum oven at a rate of 3°C / min-5°C / min (degrees Celsius per minute). After the temperature inside the vacuum chamber is raised to 80℃-85℃, it is maintained for 1h-1.5h; then, the temperature inside the vacuum chamber is raised to 120℃-125℃ at a rate of 5℃ / min-8℃ / min, and maintained for 2h-2.5h; then, the temperature inside the vacuum chamber is raised to 180℃-185℃ at a rate of 8℃ / min-10℃ / min, and maintained for 1h-1.5h; finally, the temperature inside the vacuum chamber is constantly reduced to 70℃-80℃ at a rate of 4℃ / min-6℃ / min, allowing the treated insulation layer to come into contact with the vacuum environment for natural cooling and curing.

[0012] In one possible implementation, the insulating layer further includes 1%-5% by mass of modified rosin or alkylphenol resin.

[0013] In one possible implementation, the integrated insulating metal substrate is formed as follows: a heat dissipation base plate, a given insulating layer, and an electrical metal layer are stacked; the given insulating layer is cut according to the power module requirements to obtain a stacked assembly; the stacked assembly is moved into a pressure chamber formed between a vacuum hot press and a hot plate; the press is turned off, and an initial pressure of 0.1 MPa-0.5 MPa is applied to the stacked assembly through the vacuum hot press to make initial contact between the layers of the stacked assembly; the vacuum system is started to evacuate the pressure chamber to a vacuum, and the temperature inside the pressure chamber is raised to 130°C at a rate of 2°C / min-5°C / min. After reaching -150℃, maintain the temperature for 10-20 minutes. Increase the pressure in the pressure chamber to the curing pressure of 1MPa-10MPa, and raise the temperature in the pressure chamber from the flow temperature to the target curing temperature of 175℃-180℃ at a rate of 2℃ / min-3℃ / min, maintaining a constant temperature for 60-75 minutes to ensure that the insulating layer is fully cured. After curing, stop heating and reduce the temperature in the pressure chamber to room temperature at a rate of 2℃-5℃ / min. Turn off the vacuum system and slowly fill the pressure chamber with nitrogen at a rate of 1L / min-3L / min until atmospheric pressure is reached, thus obtaining an integrated insulating metal substrate.

[0014] In one possible implementation, etching the required power circuit pattern onto an integrated insulating metal substrate includes: immersing the integrated insulating metal substrate in a 5% sulfuric acid solution for 0.5-1 minute, then removing the integrated insulating metal substrate and placing it in plasma water for a first ultrasonic cleaning at a frequency of 20-25 kHz for 3-5 minutes; immersing the integrated insulating metal substrate, after the first ultrasonic cleaning, in an 80 g / L, 30°C sodium persulfate solution for 30-45 seconds, and then removing the integrated insulating metal substrate from the sodium persulfate solution. After cleaning in 99.9% anhydrous alcohol for 3-5 minutes, place in a hot air circulating oven at 60℃-80℃ for 5-10 minutes. Place the dried integrated insulating metal substrate in the vacuum chamber of a vacuum laminator, preheat it to 100℃-11℃, and then apply a Riston 3315 or Riston 3638 type dry film to the corresponding electrical metal layer of the integrated insulating metal substrate. Use a parallel exposure machine to expose the integrated insulating metal substrate with the applied dry film according to the required power circuit. The exposure energy during the exposure process is... The vacuum chamber has a vacuum level higher than 90 kPa and an alignment accuracy lower than ±15 μm. The electrical metal layer is spray-developed using a mixture of 1% sodium carbonate and 0.1% surfactant, with a nozzle pressure of 1.8 Bar-2.2 Bar and a development time of 60-90 seconds. The integrated insulating metal substrate, after spray development, is placed in plasma water and subjected to a second ultrasonic cleaning at a frequency of 20 kHz-25 kHz for 3-5 minutes. The integrated insulating metal substrate after the second ultrasonic cleaning is then cleaned in 99.9% anhydrous alcohol for 3-5 minutes. Finally, the treated integrated insulating metal substrate is baked in a hot air circulating oven at 60℃-80℃ for 5-10 minutes to obtain the power substrate.

[0015] In one possible implementation, the thickness of the heat dissipation base plate is 1.4mm-1.6mm, and the material is any one of aluminum, aluminum alloy, copper, or copper alloy; the thickness of the electrical metal layer is 0.15mm-0.3mm, and the material is any one of aluminum, aluminum alloy, copper, or copper alloy; the electrical topology corresponding to the power demand circuit is any one of half-bridge, H-bridge, three-phase full-bridge, BUCK (step-down), BOOST (boost), or chopper circuit.

[0016] In one possible implementation, the dry film is attached to the corresponding electrical metal layer of the integrated insulating metal substrate in the following manner: the vacuum level in the vacuum chamber is adjusted to below 10 mbar, the pressure is adjusted to 0.1 MPa-0.3 MPa, and the temperature is adjusted to 90°C-95°C, and then maintained for 10-15 minutes to soften the dry film; the vacuum level in the vacuum chamber is adjusted to below 5 mbar, the pressure is adjusted to 0.5 MPa-1 MPa, and the temperature is adjusted to 100°C-105°C, and maintained for 15-20 minutes to press the dry film onto the electrical metal layer; the vacuum level in the vacuum chamber is maintained below 5 mbar, and the temperature in the vacuum chamber is reduced to 40°C-45°C at a rate of 3°C / min-5°C / min, then the pressure is released to allow the integrated insulating metal substrate to cool naturally to room temperature, thus completing the dry film attachment.

[0017] Secondly, embodiments of this application also provide a power substrate, which is manufactured by the power substrate manufacturing method provided in any of the above possible embodiments.

[0018] Thirdly, this application also provides a power module, which includes a power substrate manufactured by the power substrate manufacturing method provided in any of the above possible embodiments and a plurality of power chips. The plurality of power chips are attached to the corresponding power chip positions on the power substrate by solder and electrically connected to the etched circuit on the power substrate by wire bonding.

[0019] This application provides a method for manufacturing a power substrate, a power substrate, and a power module. The method includes: punching a first metal sheet and a second metal sheet according to the size requirements of the power module to obtain a first punched metal sheet and a second punched metal sheet; sequentially performing alkaline washing, acid washing, oxidation, and roughening treatments on the first punched metal sheet to form a heat dissipation base plate; sequentially performing cleaning and passivation treatments on the second punched metal sheet to form an electrical metal layer; stacking the heat dissipation base plate, a given insulating layer, and the electrical metal layer and then processing them in a vacuum hot press furnace to form an integrated insulating metal substrate; etching the required power circuit pattern on the integrated insulating metal substrate to obtain the power substrate. The power substrate manufactured using the method provided in this application has at least the following technical effects: (1) Through roughing, passivation and other processes, the bonding strength between the layers is higher, which greatly reduces the cracking wind direction of the power substrate during the application process and improves the reliability and safety of the power module using the power substrate. (2) The power module manufactured using the power substrate provided in this application has lower thermal resistance and fewer process steps compared to the power module of the traditional DBC ceramic substrate, which reduces processing costs and enables the power module to operate stably in a high-frequency and high-temperature environment. (3) The power substrate prepared by the process of this application has a stronger bonding strength between the electrical metal layer and the insulating layer, making it less likely for voids to appear in the power substrate during the molding process. At the same time, it takes into account toughness, interface strength and wettability, and can better combine the heat dissipation base plate and the electrical copper layer. This gives the power substrate advantages such as high thermal conductivity and resistance to thermal shock, and the peel strength is increased by at least 2 times.

[0020] (4) The existing power module packaging involves splitting the power circuit into multiple parts to form multiple DBC functional modules of different sizes, then soldering the multiple DBC functional modules onto a copper base plate, and then soldering the power chip to the corresponding position of the DBC functional module. This process requires multiple soldering operations to obtain a packaged power module. However, this application forms the power module by directly etching the circuit pattern onto the power substrate, requiring only one soldering operation, that is, directly soldering the power chip to the corresponding position of the power module, thus solving the problem that the existing power module packaging requires multiple soldering operations.

[0021] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A flowchart of a power substrate manufacturing method provided in an embodiment of this application is shown; Figure 2 This paper shows a schematic diagram of the structure of an integrated insulating metal substrate provided in an embodiment of this application; Figure 3 A schematic diagram of a power demand circuit provided in an embodiment of this application is shown; Figure 4 A schematic diagram of a power substrate provided in an embodiment of this application is shown; Figure 5 A schematic diagram of a power module provided in an embodiment of this application is shown; Figure 6 This paper illustrates a functional block diagram of a power substrate manufacturing apparatus provided in an embodiment of this application; Figure 7 A schematic diagram of the structure of an electronic device provided in an embodiment of this application is shown.

[0024] In the diagram: 1-Electrical metal layer; 2-Insulating layer; 3-Heat dissipation base plate; 3A-Heat dissipation metal layer; 3B-Roughening layer; 10-Upper bridge drive structure; 11-Lower bridge drive structure; G1-Upper bridge gate terminal; S1-Upper bridge source terminal; D1-Upper bridge drain terminal; S2-Lower bridge source terminal; G2-Lower bridge gate terminal; D2-Lower bridge drain terminal; 20-Upper bridge drain electrode region; 21-Upper bridge drain patch region; 210-Upper bridge drain body region; 211-Upper bridge drain electrode region. 22 - Bridge drain extension region; 30 - Upper bridge source region; 31 - Upper bridge gate electrode region; 50 - Lower bridge drain electrode region; 51 - Lower bridge drain patch region; 60 - Lower bridge gate electrode region; 61 - Lower bridge source electrode region; 600 - Punching module; 610 - First processing module; 620 - Second processing module; 630 - Pressing module; 640 - Etching module; 700 - Electronic equipment; 710 - Processor; 720 - Memory; 730 - Bus. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0026] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0027] Referring to the patent "A Heat Dissipation Substrate with Embedded Copper-Based IMS and Its Preparation Method" (patent number CN201810637631.2), it discloses the use of hot pressing technology to press copper plating (equivalent to an electrical metal layer), thermally conductive insulating adhesive layer and heat dissipation base plate under high pressure in a high temperature and vacuum environment to form an insulating metal substrate. In practical applications, due to cost considerations for industrial application, the materials of the heat dissipation base plate and the electrical metal layer are often different. This results in the pressure bonding surface between the electrical metal layer, thermally conductive insulating adhesive layer and heat dissipation base plate after high pressure pressing. When using the insulating metal substrate obtained in this way or the power module manufactured using the insulating substrate in certain environments (such as high temperature chip welding, power module working in a high temperature environment for a long time), the insulating metal substrate is prone to cracking and delamination, which seriously affects the reliability and safety of the power module.

[0028] Based on this, embodiments of this application provide a method for manufacturing a power substrate, a power substrate, and a power module. The power substrate manufactured using the method provided in this application, through roughening and passivation processes, achieves stronger bonding between layers, significantly reducing the risk of cracking during application and improving the reliability and safety of power modules using the power substrate. Specifically, as follows: Please see Figure 1 , Figure 1 A flowchart illustrating a power substrate manufacturing method provided in an embodiment of this application is shown. Figure 1 As shown, the power substrate manufacturing method provided in this application includes: S100. According to the size requirements of the power module, the first metal sheet and the second metal sheet are punched to obtain the first punched metal sheet and the second punched metal sheet.

[0029] S200: The first punched sheet metal is subjected to alkali washing, acid washing, oxidation and roughening treatment in sequence to form a heat dissipation base plate.

[0030] S300: The second punched sheet metal is sequentially cleaned and passivated to form an electrical metal layer.

[0031] S400: After stacking the heat dissipation base plate, the given insulation layer and the electrical metal layer, the substrate is placed in a vacuum hot press furnace for processing to form an integrated insulating metal substrate.

[0032] S500: The required power circuit pattern is etched on an integrated insulating metal substrate to obtain a power substrate.

[0033] In step S100, the first metal sheet and the second metal sheet are any one of aluminum, aluminum alloy, copper, and copper alloy. Specifically, the materials of the first metal sheet and the second metal sheet can be the same or different, and no specific restrictions are made here. The first metal sheet and the second metal sheet are punched according to the required size of the power module using laser equipment or cutting equipment, to obtain the first punched metal sheet corresponding to the first metal sheet and the second punched metal sheet corresponding to the second metal sheet.

[0034] In a preferred embodiment, step S200 includes: The first stamped sheet metal is placed in an alkaline solvent (e.g., a 10%-30% sodium hydroxide solution) at 50℃-70℃ and ultrasonically cleaned at a frequency of 20kHz-25kHz for 5min-10min. After that, the first stamped sheet metal is removed from the alkaline solvent and cleaned in 99.9% anhydrous alcohol for 3min-5min. Then, the first stamped sheet metal is placed in a hot air circulating oven at 100℃-120℃ and baked for 5min-10min to complete the drying process of the first stamped sheet metal, thus obtaining the alkaline-washed first stamped sheet metal.

[0035] In this application, by performing alkaline washing on the first punched sheet metal, surface organic matter such as grease, metal impurities, and particulate contaminants on the surface of the first punched sheet metal can be removed.

[0036] The first punched sheet metal after alkaline washing is placed in an acidic solvent at 35°C-65°C (for example, nitric acid with a concentration of 5%-15%). After ultrasonic cleaning of the first punched sheet metal in an acidic solvent at a frequency of 20kHz-25kHz (kilohertz) for 3-5 minutes, the first punched sheet metal is removed from the acidic solvent and placed in 99.9% anhydrous alcohol for 3-5 minutes. Then, the first punched sheet metal is removed from the anhydrous alcohol and placed in a hot air circulating oven at 100℃-120℃ for 5-10 minutes to complete the drying process of the first punched sheet metal again, thus obtaining the acid-washed first punched sheet metal.

[0037] The first punched sheet metal after pickling is subjected to an oxidation treatment to form an oxide layer on its surface, resulting in a treated first punched sheet metal. In one specific embodiment, the oxidation treatment includes: placing the pickled first punched sheet metal in a fixture and feeding it into a high-temperature furnace tube (exemplarily, a diffusion furnace); heating the high-temperature furnace tube to 100°C-120°C at a rate of 5°C / min-10°C / min; introducing an inert gas (exemplarily, nitrogen) into the high-temperature furnace tube to maintain a uniform and stable temperature; and then continuously introducing high-purity oxygen into the high-temperature furnace tube for 30 minutes at a rate of 1L / min-10L / min. For n-60min, an oxide layer is formed on the surface of the first stamped sheet metal. The temperature inside the high-temperature furnace tube is cooled to room temperature at a rate of 3℃ / min-5℃ / min to prevent the first stamped sheet metal from cracking under thermal shock. The oxidized first stamped sheet metal is removed from the high-temperature furnace tube and placed in 99.9% anhydrous alcohol. It is then ultrasonically cleaned for 5min-10min at a frequency of 5kHz-15kHz. After the third ultrasonic cleaning, the first stamped sheet metal is placed in a hot air circulating oven at 50℃-75℃ and baked for 10min-15min to complete the drying process, thus obtaining the oxidized first stamped sheet metal.

[0038] Please see Figure 2 , Figure 2 A schematic diagram of an integrated insulating metal substrate provided in an embodiment of this application is shown. Figure 2 As shown, the integrated insulating metal substrate includes an electrical metal layer 1, a given insulating layer 2, and a heat dissipation base plate 3 stacked from top to bottom. In this application, the first stamped sheet metal after oxidation treatment is used as the heat dissipation metal layer 3A corresponding to the heat dissipation base plate 3.

[0039] Pickling removes the naturally formed thin oxide layer on the first punched sheet metal. Then, the pickled first punched sheet metal is re-oxidized to increase the density of the oxide layer, ensuring the insulation and mechanical properties of the subsequently formed heat dissipation base plate.

[0040] The first punched sheet metal (i.e. heat dissipation metal layer 3A) after oxidation treatment is subjected to surface roughening treatment to form a roughening layer on the surface of the heat dissipation metal layer. The heat dissipation base plate is formed by the stacked roughening layer and the heat dissipation metal. The purpose of roughening treatment is to improve the bonding force between the heat dissipation base plate and the given insulation layer 2 in subsequent processes.

[0041] Preferably, the roughening treatment specifically includes: forming a roughening layer 3B on the surface of the first punched metal sheet (i.e., the heat dissipation metal layer 3A) after oxidation treatment by sandblasting, wherein the roughening layer 3B is aluminum oxide with a thickness of 50μm~100μm (micrometers). ) Sand particles.

[0042] In a preferred embodiment, step S300 includes: The second-cut sheet metal was placed in 99.9% anhydrous alcohol and ultrasonically cleaned for 6-8 minutes at a frequency of 20kHz-25kHz. After the first ultrasonic cleaning, the second-cut sheet metal was placed in a hot air circulating oven at 100℃-120℃ for a first drying treatment of 5-10 minutes, resulting in the second-cut sheet metal after the first drying treatment. The purpose of cleaning the second-cut sheet metal with 99.9% anhydrous alcohol is to thoroughly clean the surface of the second-cut sheet metal, remove oil and other organic matter, and ensure that the surface of the electrical metal layer formed subsequently has good adhesion in subsequent processes.

[0043] After the first drying treatment, the second punched sheet metal is immersed in a benzotriazole solution with a concentration of 85±10% and a temperature of 40±2℃ for 3-5 minutes to form a passivation layer of 1μm-3μm on the surface of the second punched sheet metal, so as to avoid excessive oxidation of the second punched sheet metal and improve its corrosion resistance.

[0044] The passivated second punched sheet metal is placed in 99.9% anhydrous alcohol and ultrasonically cleaned for 15-20 minutes at a frequency of 20kHz-25kHz. After the second ultrasonic cleaning, the second punched sheet metal is placed in a hot air circulating oven at 100℃-120℃ for a second drying treatment of 5-10 minutes to obtain the electrical metal layer.

[0045] In a preferred embodiment, in step S400, as Figure 2 As shown, the corresponding components of the given metal layer provided in this application include: epoxy resin (exemplarily, HT-04503 film can be selected), toughening agent with a mass fraction of 10%-35% (exemplarily, carboxyl-terminated liquid nitrile rubber CTBN can be selected to improve peel strength), high-temperature curing agent with a mass fraction of 10%-20% (exemplarily, HT-53 can be selected to achieve medium and low temperature rapid curing and improve reaction efficiency), and nanoparticles with a mass fraction of 3%-8% and a particle size of <50nm (nanometer) (exemplarily, silicon dioxide can be selected). / alumina (For example, KH-560 can be used to enhance rigidity and inhibit crack propagation) and 1%-2% by mass of silane coupling agent (for example, KH-560 can be used to improve the bonding force of the resin / metal interface).

[0046] In another preferred embodiment, the given insulation layer 2 provided in this application may also contain 1%-5% modified rosin or alkylphenol resin to improve the initial tack of the given insulation layer and ensure that it does not shift during installation.

[0047] In a preferred embodiment, the method provided in this application further includes: The toughening agent and epoxy resin were stirred in a container at 70°C for 3 hours to form a homogeneous prepolymer. The prepolymer was then cooled to 50°C by natural cooling. A high-temperature curing agent, nanoparticles and silane coupling agent were added to the container and stirred evenly with the prepolymer to remove bubbles, thus obtaining the insulation layer to be treated. The insulation layer to be treated was placed in a vacuum oven for curing to obtain the given insulation layer.

[0048] In a specific example, the curing process includes: The temperature inside the vacuum chamber of the vacuum oven is raised to 80℃-85℃ at a rate of 3℃ / min-5℃ / min and maintained for 1h-1.5h. Then, the temperature inside the vacuum chamber is raised to 120℃-125℃ at a rate of 5℃ / min-8℃ / min and maintained for 2h-2.5h. Next, the temperature inside the vacuum chamber is raised to 180℃-185℃ at a rate of 8℃ / min-10℃ / min and maintained for 1h-1.5h. Finally, the temperature inside the vacuum chamber is constantly reduced to 70℃-80℃ at a rate of 4℃ / min-6℃ / min, allowing the treated insulation layer to come into contact with the vacuum environment for natural cooling and curing.

[0049] In a preferred embodiment, step S400 includes: like Figure 2 As shown, the heat dissipation base plate 3 (including heat dissipation metal layer 3A and roughening layer 3B), the given insulation layer 2 and the electrical metal layer 1 are stacked. According to the power module requirements, the given insulation layer is cut to obtain the stacked assembly. It is necessary to ensure that the size of the cut given insulation layer is slightly larger than the size of the heat dissipation base plate / electrical metal layer to compensate for flow and prevent edge glue shortage. For example, the given insulation layer is ensured to be 1mm-3mm larger on one side than the heat dissipation base plate / electrical metal layer.

[0050] The laminated assembly is moved into the pressure chamber formed between the vacuum hot press and the hot plate. The press is turned off, and an initial pressure of 0.1MPa-0.5MPa is applied to the laminated assembly through the vacuum hot press to make initial contact between the layers of the laminated assembly and prevent displacement. The vacuum system is started to evacuate the pressure chamber to a vacuum. The temperature inside the pressure chamber is raised to 130℃-150℃ at a rate of 2℃ / min-5℃ / min and maintained for 10min-20min. This allows the insulation layer to soften, melt, and flow fully, wetting the surface of the heat dissipation base plate and the electrical metal layer. The internal gas is then discharged, allowing the heat dissipation base plate and the electrical metal layer to make full contact and improve the bonding force of the bonding surface.

[0051] Subsequently, the pressure inside the pressure chamber is increased to the curing pressure of 1MPa-10MPa, and the temperature inside the pressure chamber is increased from the flow temperature to the target curing temperature of 175℃-180℃ at a rate of 2℃ / min-3℃ / min, and kept constant for 60min-75min, so that the insulation layer can fully undergo cross-linking reaction (curing) and further strengthen the connection between the electrical metal layer and the heat dissipation base plate.

[0052] After curing, stop heating and reduce the temperature inside the pressure chamber to room temperature at a rate of 2℃-5℃ / min (for example, after reducing the temperature to 50℃, the pressure inside the pressure chamber can be reduced to 0.3MPa-0.5MPa to save costs). This prevents delamination or warping caused by insulation shrinkage, differences in thermal expansion coefficients between different layers, or internal thermal stress during the cooling process, and avoids subsequent cracking due to such problems.

[0053] Turn off the vacuum system and slowly fill the pressure chamber with nitrogen (or dry air) at a rate of 1L / min-3L / min (liters / minute) until atmospheric pressure is reached, thus obtaining an integrated insulating metal substrate.

[0054] The integrated insulating metal substrate manufactured by the method provided in steps S100 to S400 of this application has a stronger bond between the electrical metal layer and the insulating layer, making it less prone to voids during the molding process. It also takes into account toughness, interface strength and wettability, and can better bond the heat dissipation base plate and the electrical metal layer together. This gives the integrated insulating metal substrate advantages such as high thermal conductivity and resistance to thermal shock, and the peel strength is increased by more than 2 times.

[0055] In a preferred embodiment, step S500 includes: The integrated insulating metal substrate was placed in 5% sulfuric acid ( After immersing in the solution for 0.5-1 minute, the integrated insulating metal substrate is removed and placed in plasma water (for example, DI, "Deionized Water"), and subjected to a first ultrasonic cleaning at a frequency of 20kHz-25kHz for 3-5 minutes; the integrated insulating metal substrate after the first ultrasonic cleaning is then placed in sodium persulfate solution at 80g / L (grams per liter) and 30°C. The solution is left to stand for 30-45 seconds to remove a 0.3μm-0.8μm copper layer, thereby increasing the surface area for subsequent process reactions.

[0056] From the integrated insulating metal substrate After removing the product from the solution and washing it in 99.9% anhydrous alcohol for 3-5 minutes, place it in a hot air circulating oven at 60℃-80℃ for 5-10 minutes to complete the drying process.

[0057] After drying, the integrated insulating metal substrate is placed in the vacuum chamber of a vacuum laminator and preheated to 100℃-11℃. Then, a dry film of type Riston3315 or Riston3638 is attached to the corresponding electrical metal layer of the integrated insulating metal substrate.

[0058] In one specific embodiment, the dry film is attached to the electrical metal layer corresponding to the integrated insulating metal substrate in the following manner: The vacuum level in the vacuum chamber is adjusted to ≤10 mbar, the pressure to 0.1 MPa-0.3 MPa, and the temperature to 90℃-95℃, respectively, and maintained for 10-15 minutes to soften the dry film. Then, the vacuum level in the vacuum chamber is adjusted to ≤5 mbar, the pressure to 0.5 MPa-1 MPa, and the temperature to 100℃-105℃, respectively, and maintained for 15-20 minutes to fully press the dry film onto the electrical metal layer. The vacuum level in the vacuum chamber is maintained below 5 mbar, and the temperature in the vacuum chamber is reduced to 40℃-45℃ at a rate of 3℃ / min-5℃ / min. Then, the pressure is released, and the integrated insulating metal substrate is allowed to cool naturally to room temperature, completing the dry film attachment.

[0059] A parallel exposure machine (exemplary, corresponding to a wavelength of 365nm, collimation angle <2°) is used to expose the integrated insulating metal substrate with dry film attachment according to the required power circuit, wherein the exposure energy during the exposure process is... (millijoules per square centimeter), the vacuum degree corresponding to the vacuum chamber is higher than 90 kPa (pressure unit, kilopascal), and the alignment accuracy is lower than ±15 μm (length unit, micrometer).

[0060] Use sodium carbonate with a concentration of 1% ( A surfactant with a concentration of 0.1% (exemplary, any one of polyoxyethylene alkyl ether, polyoxyethylene glycerol ether, or propylene glycol butyl ether can be used, with the surfactant temperature at 30℃±1℃) is sprayed and developed on the electrical metal layer, wherein the nozzle pressure is 1.8 Bar-2.2 Bar (pressure unit, bar), and the development time is 60 seconds-90 seconds.

[0061] Subsequently, the integrated insulating metal substrate after spray development was placed in plasma water and subjected to a second ultrasonic cleaning at a frequency of 20kHz-25kHz for 3min-5min. After the second ultrasonic cleaning, the integrated insulating metal was placed in 99.9% anhydrous alcohol for 3min-5min and then baked in a hot air circulating oven at 60℃-80℃ for 5min-10min to obtain the power substrate.

[0062] In one specific embodiment, the thickness of the heat dissipation base plate is 1.4mm-1.6mm, and the material is any one of aluminum, aluminum alloy, copper, and copper alloy.

[0063] The thickness of the electrical metal layer is 0.15mm-0.3mm, and the material is any one of aluminum, aluminum alloy, copper, or copper alloy.

[0064] The electrical topology corresponding to the power demand circuit can be any one of the following: half-bridge, H-bridge, three-phase full-bridge, BUCK (step-down), BOOST (boost), or chopper circuit.

[0065] Based on the same concept, this application also provides a power substrate manufactured using the power substrate manufacturing method provided in the above embodiments.

[0066] Please see Figure 3 , Figure 3 A schematic diagram of a power demand circuit according to an embodiment of this application is shown. Figure 3 The power demand circuit shown includes an upper bridge drive structure 10 and a lower bridge drive structure 11 connected in series. The upper bridge drive structure 10 has an upper bridge gate terminal G1 and an upper bridge source terminal S1 respectively. The drain of the upper bridge drive structure 10 is connected to the source of the lower bridge drive structure 11. The drain and source of the upper bridge drive structure 10 also have corresponding upper bridge drain terminals D1 and upper bridge source terminals S1 respectively. The source of the lower bridge drive structure 11 has a lower bridge source terminal S2. The gate of the lower bridge drive structure 11 has a lower bridge gate terminal G2. The drain of the lower bridge drive structure 11 also has a corresponding terminal D2.

[0067] Please see Figure 4 , Figure 4 A schematic diagram of a power substrate provided in an embodiment of this application is shown. Specifically, patterns are etched onto an integrated insulating metal substrate A. Figure 3 The required power circuit pattern shown can be obtained. Figure 4 The power substrate shown.

[0068] like Figure 4 As shown, according to Figure 3 The provided power circuit pattern on the integrated insulating metal substrate A includes an upper bridge drain electrode region 20 corresponding to the upper bridge drain terminal D1, an upper bridge drain patch region 21 (divided into an upper bridge drain body region 210 and an upper bridge drain extension region 211), an upper bridge source region 22 corresponding to the upper bridge source terminal S1, an upper bridge source electrode region 31, an upper bridge gate electrode region 30 corresponding to the upper bridge gate terminal G1, a lower bridge drain electrode region 50 and a lower bridge drain patch region 51 corresponding to the lower bridge drain terminal D2, a lower bridge source electrode region 61 corresponding to the lower bridge source terminal S2, and a lower bridge gate electrode region 60 corresponding to the lower bridge gate terminal G2.

[0069] like Figure 4 As shown, the upper bridge drain electrode region 21 is located above the upper bridge source electrode region 22, the upper bridge drain electrode region 20 is located to the left of the upper bridge drain electrode region 21 and is electrically connected to the upper bridge drain electrode region 21 through solder, the upper bridge source electrode region 31 is located above the upper bridge gate electrode region 30, one end of the upper bridge gate electrode region 30 is located above the upper bridge drain body region 210 and extends horizontally along the integrated insulating metal substrate, and the other end of the upper bridge gate electrode region 30 is formed to the right and above the lower bridge drain electrode region 50.

[0070] One end of the upper bridge source electrode region 31 is located above the upper bridge drain patch region 21 (upper bridge drain body region 210 or upper bridge drain extension region 211) and extends horizontally along the integrated insulating metal substrate. The other end of the upper bridge source electrode region 31 is formed on the right side of the lower bridge package region, adjacent to the other end of the upper bridge gate electrode region.

[0071] The lower bridge drain patch area 51 is located below the upper bridge drain extension area 211, and the lower bridge drain electrode area 50 is located to the right of the lower bridge drain patch area 51 and is electrically connected to the lower bridge drain patch area 51 through solder.

[0072] One end of the lower bridge source electrode region 61 is located to the left of the lower bridge drain patch region 51 and connected to the upper bridge drain extension region 211. One end of the lower bridge source electrode region 61 extends horizontally along the integrated insulating metal substrate, and the other end of the lower bridge source electrode region 61 is formed at the right side of the lower bridge package region and adjacent to the other end of the lower bridge gate electrode region.

[0073] Based on the same concept, this application also provides a power module, which includes a power substrate manufactured by the method provided in the above embodiments and a plurality of power chips. The plurality of power chips are attached to the power substrate at corresponding power chip positions by solder and electrically connected to the etched circuit on the power substrate by wire bonding.

[0074] In one specific embodiment, please refer to Figure 5 , Figure 5 A schematic diagram of a power module provided in an embodiment of this application is shown. For example... Figure 5 The power module shown uses Figure 3 The power substrate shown will be used with Figure 3 The upper bridge power chip corresponding to the upper bridge drive structure 10 shown is attached to the upper bridge drain body area 210, and the lower bridge power chip corresponding to the lower bridge drive structure 11 is attached to the lower bridge drain patch area 51. The power substrate with the power chip attached is transferred to a PINK-type vacuum formic acid furnace, and the power chip is soldered to the corresponding area in a vacuum environment. Furthermore, wire bonding is performed between the upper bridge source electrode area 31 and the upper bridge source electrode area 22 to realize the electrical connection between the upper bridge source electrode area 31 and the upper bridge source electrode area 22.

[0075] Then, bonding wires are respectively installed between the gate of the upper bridge power chip and the upper bridge gate electrode region 30, between the source of the upper bridge power chip and the upper bridge source region 22, between the gate of the lower bridge power chip and the lower bridge gate electrode region 60, and between the source of the lower bridge power chip and the upper bridge drain patch region 21 to realize the electrical connection between the power chip and the corresponding circuit on the power substrate, forming a power module.

[0076] The areas of the power module that require external electrode connection after wire bonding are assembled with pre-prepared electrode plates using a fixture. Then, they are placed in a box-type vacuum formic acid furnace for secondary welding to obtain a semi-finished power module. Then, a static parameter testing machine is used to perform performance testing on the semi-finished power module. For the semi-finished power module that passes the performance test, glue is applied to assemble the shell and the electrodes are pressed together. A vacuum potting machine is used to pot the semi-finished power module that has undergone motor pressing to protect the chip and conductive wires, resulting in the power module to be tested. The power module to be tested is then subjected to final functional testing (e.g., insulation withstand voltage, static and dual-pulse dynamic tests). The power module that passes the final functional testing is determined as the final finished power module.

[0077] Based on the same application concept, this application also provides a power substrate manufacturing apparatus corresponding to the power substrate manufacturing method provided in the above embodiments. Since the principle of the apparatus in this application to solve the problem is similar to the power substrate manufacturing method in the above embodiments of this application, the implementation of the apparatus can refer to the implementation of the method, and the repeated parts will not be described again.

[0078] Please see Figure 6 , Figure 6 A functional block diagram of a power substrate manufacturing apparatus provided in an embodiment of this application is shown. Figure 6 As shown, the device includes: The stamping module 600 is used to stamp the first metal sheet and the second metal sheet according to the size requirements of the power module, to obtain the first stamped metal sheet and the second stamped metal sheet. The first processing module 610 is used to sequentially perform alkaline washing, acid washing, oxidation and roughening treatments on the first punched sheet metal to form a heat dissipation base plate. The second processing module 620 is used to sequentially clean and passivate the second punched sheet metal to form an electrical metal layer. The lamination module 630 is used to stack the heat dissipation base plate, the given insulating layer and the electrical metal layer and then place them in a vacuum hot press furnace for processing to form an integrated insulating metal substrate. Etching module 640 is used to etch the required power circuit pattern on an integrated insulating metal substrate to obtain a power substrate.

[0079] Based on the same application concept, please refer to Figure 7 , Figure 7 A schematic diagram of the structure of an electronic device provided in an embodiment of this application is shown. For example... Figure 7 As shown, the electronic device 700 includes a processor 710, a memory 720, and a bus 730. The memory 720 stores machine-readable instructions that can be executed by the processor 710. When the electronic device 700 is running, the processor 710 and the memory 720 communicate through the bus 730. The machine-readable instructions are executed by the processor 710 to perform the steps of the manufacturing method of the power module provided in any of the above embodiments.

[0080] Based on the same concept, this application also provides a computer-readable storage medium storing a computer program, which, when run by a processor, executes the steps of the power substrate manufacturing method provided in the above embodiments.

[0081] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems and devices described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division; in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection may be through some communication interfaces; the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms.

[0082] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0083] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0084] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0085] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for manufacturing a power substrate, characterized in that, The method includes: According to the size requirements of the power module, the first metal sheet and the second metal sheet are punched to obtain the first punched metal sheet and the second punched metal sheet. The first punched sheet metal is subjected to alkaline washing, acid washing, oxidation and roughening treatment in sequence to form a heat dissipation base plate; The second punched sheet metal is sequentially cleaned and passivated to form an electrical metal layer; After the heat dissipation base plate, the given insulation layer and the electrical metal layer are stacked, they are placed in a vacuum hot press furnace for processing to form an integrated insulating metal substrate. The required power circuit pattern is etched on the integrated insulating metal substrate to obtain a power substrate.

2. The power substrate manufacturing method according to claim 1, characterized in that, The first punched sheet metal is subjected to alkaline washing, pickling, oxidation, and roughening treatments in sequence, including: The first punched sheet metal is placed in an alkaline solvent at 50℃-70℃ and ultrasonically cleaned for 5min-10min at a frequency of 20kHz-25kHz. After the first ultrasonic cleaning, the first punched sheet metal is placed in 99.9% anhydrous alcohol for 3min-5min and then baked in a hot air circulating oven at 100℃-120℃ for 5min-10min to obtain the alkaline-washed first punched sheet metal. The first punched sheet metal after alkaline washing is placed in an acidic solvent at 35℃-65℃ and ultrasonically cleaned for 3min-5min at a frequency of 20kHz-25kHz. The first punched sheet metal after the second ultrasonic cleaning is then cleaned in 99.9% anhydrous alcohol for 3min-5min. The treated first punched sheet metal is then baked in a hot air circulating oven at 100℃-120℃ for 5min-10min to obtain the first punched sheet metal after pickling. The first punched sheet metal after pickling is subjected to an oxidation treatment to obtain the first punched sheet metal after oxidation treatment. The first punched sheet metal after oxidation treatment is roughened to form a heat dissipation base plate.

3. The power substrate manufacturing method according to claim 2, characterized in that, The oxidation treatment includes: The first punched sheet metal after pickling is placed in a fixture and fed into a high-temperature furnace tube, and the high-temperature furnace tube is heated to 100℃-120℃ at a rate of 5℃ / min-10℃ / min. Inert gas is introduced into the high-temperature furnace tube to keep the temperature in the high-temperature furnace tube stable and uniform. High-purity oxygen is continuously introduced into the high-temperature furnace tube at a rate of 1L / min-10L / min for 30min-60min to form an oxide layer on the surface of the first punched sheet metal. The temperature inside the high-temperature furnace tube was cooled to room temperature at a rate of 3℃ / min-5℃ / min. The oxidized first punched sheet metal was removed from the high-temperature furnace tube and placed in 99.9% anhydrous alcohol. It was then subjected to a third ultrasonic cleaning at a frequency of 5kHz-15kHz for 5min-10min. After the third ultrasonic cleaning, the first punched sheet metal is placed in a hot air circulating oven at 50℃-75℃ and baked for 10min-15min to obtain the first punched sheet metal after oxidation treatment.

4. The power substrate manufacturing method according to claim 2, characterized in that, The roughening process includes: Alumina particles of 50μm to 100μm are formed on the surface of the first punched sheet metal after oxidation treatment by sandblasting.

5. The power substrate manufacturing method according to claim 4, characterized in that, The second-cut sheet metal is sequentially cleaned and passivated, including: The second punched sheet metal was placed in 99.9% anhydrous alcohol and ultrasonically cleaned for 6-8 minutes at a frequency of 20kHz-25kHz. After the first ultrasonic cleaning, the second punched sheet metal is placed in a hot air circulating oven at 100℃-120℃ for a first drying treatment of 5min-10min. After the first drying treatment, the second punched sheet metal is immersed in a benzotriazole solution with a concentration of 85±10% and a temperature of 40±2℃ for 3min-5min to form a passivation layer of 1μm-3μm on the surface of the second punched sheet metal. The passivated second punched sheet metal was placed in 99.9% anhydrous alcohol and subjected to a second ultrasonic cleaning at a frequency of 20kHz-25kHz for 15-20 minutes. The second punched sheet metal, after undergoing a second ultrasonic cleaning, is placed in a hot air circulating oven at 100℃-120℃ for a second drying process of 5-10 minutes to obtain the electrical metal layer.

6. The power substrate manufacturing method according to claim 4, characterized in that, The given insulating layer comprises epoxy resin, toughening agent with a mass fraction of 10%-35%, high-temperature curing agent with a mass fraction of 10%-20%, nanoparticles with a mass fraction of 3%-8% and a particle size of <50nm, and silane coupling agent with a mass fraction of 1%-2%.

7. The power substrate manufacturing method according to claim 6, characterized in that, The given insulating layer is formed by processing in the following manner: The toughening agent and epoxy resin were stirred in a container at 70°C for 3 hours to form a homogeneous prepolymer, and the prepolymer was cooled to 50°C by natural cooling. High-temperature curing agent, nanoparticles and silane coupling agent are added to a container, and the prepolymer is stirred evenly and degassed to obtain the insulation layer to be treated. The insulation layer to be treated is placed in a vacuum oven for curing to obtain the given insulation layer; The curing process includes: The temperature inside the vacuum chamber of the vacuum oven is raised to 80℃-85℃ at a rate of 3℃ / min-5℃ / min and maintained for 1h-1.5h. The temperature inside the vacuum chamber is raised to 120-125℃ at a rate of 5℃ / min-8℃ / min and maintained for 2h-2.5h. The temperature inside the vacuum chamber is raised to 180-185℃ at a rate of 8℃ / min-10℃ / min and maintained for 1h-1.5h. After the temperature and pressure inside the vacuum chamber are reduced to 70℃-80℃ at a rate of 4℃ / min-6℃ / min, the treated insulation layer is brought into contact with the vacuum environment for natural cooling and curing.

8. The power substrate manufacturing method according to claim 6, characterized in that, The insulating layer also includes 1%-5% by mass of modified rosin or alkylphenol resin.

9. The power substrate manufacturing method according to claim 1, characterized in that, The integrated insulating metal substrate is formed in the following manner: The heat dissipation base plate, the given insulation layer and the electrical metal layer are stacked together. The given insulation layer is cut according to the power module requirements to obtain the stacked assembly. The laminated assembly is moved into the pressure chamber formed between the vacuum hot press and the hot plate. The press is turned off, and an initial pressure of 0.1MPa-0.5MPa is applied to the laminated assembly through the vacuum hot press to make the layers of the laminated assembly initially contact. Start the vacuum system, evacuate the pressure chamber to a vacuum, and raise the temperature inside the pressure chamber to 130℃-150℃ at a rate of 2℃ / min-5℃ / min, and maintain it for 10min-20min. Increase the pressure inside the pressure chamber to the curing pressure of 1MPa-10MPa, and increase the temperature inside the pressure chamber from the flow temperature to the target curing temperature of 175℃-180℃ at a rate of 2℃ / min-3℃ / min, and maintain the constant temperature for 60min-75min to ensure that the insulation layer is fully cured. After curing is complete, stop heating and reduce the temperature inside the pressure chamber to room temperature at a rate of 2℃-5℃ / min. The vacuum system is turned off, and nitrogen gas is slowly introduced into the pressure chamber at a rate of 1L / min-3L / min until atmospheric pressure is reached, thus obtaining an integrated insulating metal substrate.

10. The power substrate manufacturing method according to claim 1, characterized in that, The required power circuit pattern is etched onto the integrated insulating metal substrate, including: After immersing the integrated insulating metal substrate in a 5% sulfuric acid solution for 0.5 min to 1 min, the integrated insulating metal substrate is removed and placed in plasma water, and subjected to a first ultrasonic cleaning for 3 min to 5 min using a frequency of 20 kHz to 25 kHz. After the first ultrasonic cleaning, the integrated insulating metal substrate is placed in an 80g / L, 30℃ sodium persulfate solution and left to stand for 30-45 seconds. The integrated insulating metal substrate is then removed from the sodium persulfate solution and cleaned in 99.9% anhydrous alcohol for 3-5 minutes. Finally, it is placed in a hot air circulating oven at 60℃-80℃ and baked for 5-10 minutes. After drying, the integrated insulating metal substrate is placed in the vacuum chamber of a vacuum laminator and preheated to 100℃-11℃. Then, a dry film of type Riston3315 or Riston3638 is attached to the corresponding electrical metal layer of the integrated insulating metal substrate. A parallel exposure machine is used to expose the integrated insulating metal substrate with dry film attachment completed according to the required power circuit. The exposure energy during the exposure process is... The vacuum chamber corresponds to a vacuum level higher than 90 kPa and an alignment accuracy lower than ±15 μm; The electrical metal layer was sprayed and developed using a mixture of 1% sodium carbonate and 0.1% surfactant, with a nozzle pressure of 1.8 Bar-2.2 Bar and a development time of 60-90 seconds. After spraying and developing, the integrated insulating metal substrate is placed in plasma water and subjected to a second ultrasonic cleaning at a frequency of 20kHz-25kHz for 3min-5min. After the second ultrasonic cleaning, the integrated insulating metal is placed in 99.9% anhydrous alcohol for 3min-5min. The processed integrated insulating metal is placed in a hot air circulating oven at 60℃-80℃ and baked for 5min-10min to obtain the power substrate.

11. The power substrate manufacturing method according to claim 1, characterized in that, The thickness of the heat dissipation base plate is 1.4mm-1.6mm, and the material is any one of aluminum, aluminum alloy, copper, and copper alloy; The thickness of the electrical metal layer is 0.15mm-0.3mm, and the material is any one of aluminum, aluminum alloy, copper, and copper alloy; The electrical topology corresponding to the power demand circuit can be any one of the following: half-bridge, H-bridge, three-phase full-bridge, BUCK, BOOST, or chopper circuit.

12. The power substrate manufacturing method according to claim 10, characterized in that, The dry film is attached to the corresponding electrical metal layer of the integrated insulating metal substrate in the following manner: After adjusting the vacuum level in the vacuum chamber to below 10 mbar, the pressure to 0.1 MPa-0.3 MPa, and the temperature to 90℃-95℃, maintain these conditions for 10-15 minutes to soften the dry film. The vacuum level in the vacuum chamber was adjusted to below 5 mbar, the pressure to 0.5 MPa-1 MPa, and the temperature to 100℃-105℃, and maintained for 15 min-20 min, so that the dry film was fully pressed onto the electrical metal layer. Maintain the vacuum level in the vacuum chamber below 5 mbar, and reduce the temperature in the vacuum chamber to 40℃-45℃ at a rate of 3℃ / min-5℃ / min. Then release the pressure and allow the integrated insulating metal substrate to cool naturally to room temperature, thus completing the dry film bonding.

13. A power substrate, characterized in that, The power substrate is manufactured by any of the power substrate manufacturing methods provided in claims 1-12.

14. A power module, characterized in that, The power module includes a power substrate manufactured by any one of the methods described in claims 1-12 and a plurality of power chips. The plurality of power chips are attached to the power substrate at corresponding power chip positions by solder and are electrically connected to the etched circuit on the power substrate by wire bonding.

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