Sintering process of chip and ceramic substrate

Abstract

The invention discloses a sintering process of a chip and a ceramic substrate. The sintering process comprises the following steps: S1, coating a silver paste layer on the ceramic substrate; s2, the protective film and the chip are adsorbed by a suction nozzle; s3, positioning the suction nozzle to a preset area of the ceramic substrate; s4, the suction nozzle adsorbs the chip, the back face of the chip makes contact with the silver paste layer, and the chip and the protective film are attached to the surface of the silver paste layer at the same time; s5, applying constant temperature and pressure through the suction nozzle to enable the silver paste, the back surface of the chip and the ceramic substrate to form a metal atom migration condition; s6, the sintering temperature and time are kept; and S7, after sintering is completed, the protective film is removed, and the chip and ceramic substrate interconnection structure is obtained. By integrating pre-sintering and sintering functions into single equipment, synchronous adsorption and accurate positioning of a protective film and a chip are realized by adopting a double-vacuum-pipeline suction nozzle, so that the production period of a sintering process is remarkably shortened, the precision and reliability of interconnection of the chip and a ceramic substrate are improved, and the sintering process with high efficiency, low cost and high consistency is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of chip manufacturing technology, and in particular relates to a sintering process of a chip and a ceramic substrate. Background Art

[0002] In the power semiconductor industry, the interconnection between chips and ceramic substrates is typically achieved using a silver paste sintering process, which requires two steps: pre-sintering and bonding, and high-temperature sintering. Traditionally, pre-sintering bonding machines are limited by temperature (≤150°C) and pressure (≤10kg), making them unable to meet the 250°C and 40kg conditions required for sintering. Furthermore, it is difficult to integrate a protective film to protect the chip surface. While specialized sintering equipment can provide a high-temperature, high-pressure environment, it lacks the ability to transfer chips, resulting in extended process cycles and low efficiency. Furthermore, traditional sintering equipment struggles to accurately apply pressure to individual chips in products with high-density chip layouts, which can easily lead to uneven interconnections or chip damage, and the investment cost of separate equipment is high. Therefore, there is an urgent need for a single-machine solution that can integrate bonding and sintering functions, support the simultaneous application of protective films, and achieve high-precision pressure application to improve process efficiency, reduce costs, and ensure product quality. Summary of the Invention

[0003] The object of the present invention is to provide a sintering process for a chip and a ceramic substrate to solve the problems raised in the above background technology.

[0004] In view of this, the present invention provides a sintering process for a chip and a ceramic substrate, comprising the following steps: S1 provides a ceramic substrate, and coated with silver paste on its surface to form a uniform silver paste layer; S2 provides a nozzle with dual vacuum lines, wherein the first vacuum line adsorbs the protective film through a circular opening, and the second vacuum line adsorbs the chip through an X-shaped slot or other shaped slot; S3. Controlling the first vacuum line of the nozzle to open, adsorbing the protective film, and positioning it to a predetermined area of ​​the ceramic substrate; S4. Control the second vacuum line of the suction nozzle to open, adsorb the chip, and adjust its position so that the back of the chip contacts the silver paste layer. Move the suction nozzle with the chip and protective film adsorbed to the top of the ceramic substrate so that the chip and protective film are simultaneously attached to the surface of the silver paste layer; S5. Apply constant temperature and pressure through the nozzle, wherein the temperature is controlled at 200-250°C and the pressure is controlled at 30-40kg, so that the silver paste forms metal atom migration conditions with the back of the chip and the ceramic substrate; S6. Maintain the sintering temperature and time for 1-5 minutes to ensure that the silver paste is fully sintered and forms a stable interconnected structure; S7. After sintering is completed, the protective film is removed to obtain the interconnection structure between the chip and the ceramic substrate.

[0005] A further embodiment of the present invention is that in step S1, the surface of the ceramic substrate is plasma cleaned or ultrasonically cleaned, and the surface energy is ≥50 mN / m. The silver paste is applied by screen printing, the screen mesh is 200-300 mesh, the printing thickness is 10-50 μm, and the surface roughness Ra after leveling is ≤2 μm. The silver paste contains nanosilver particles and glass powder, and the glass powder accounts for 0.1-1wt%. After the silver paste is applied, it is preheated at 50-80°C for leveling for 1-5 minutes, and the thickness tolerance is monitored online by a laser thickness gauge to within ±3 μm.

[0006] A further implementation scheme of the present invention is that in step S2, the first vacuum pipeline of the suction nozzle is a circular hole array with a hole diameter of 0.3-0.8mm, and the opening area accounts for 30-50% of the bottom surface of the suction nozzle; the second vacuum pipeline is X-shaped or radially grooved with a groove width of 0.1-0.5mm and a depth of 0.2-0.5mm. The internal channel diameters of the first vacuum pipeline and the second vacuum pipeline are 2-3mm and 1-2mm respectively, and they are connected to independent vacuum pump systems. The suction nozzle is made of silicon carbide or zirconium oxide ceramics.

[0007] A further implementation scheme of the present invention is that in step S3, the opening of the first vacuum line is controlled by a solenoid valve, the response time is ≤10ms, the vacuum degree is 0.05-0.1MPa, the adsorption force is 5-10N, the protective film is made of polyimide material, with a thickness of 20-100μm, and the pre-cut size is 0.5-1mm larger than the chip. The release paper is automatically removed by a peeling roller before adsorption, and the positioning uses a visual system to identify the substrate mark and the edge of the protective film.

[0008] A further implementation scheme of the present invention is that in step S4, the opening delay of the second vacuum pipeline is 50-100ms, the vacuum degree is 0.1-0.2MPa, the adsorption force is 10-20N, and the vacuum degree is dynamically adjusted according to the chip size. Before the chip is adsorbed, the back electrode is identified by the upward camera, and the silver paste layer is photographed by the downward camera. The dual cameras have a collaborative positioning accuracy of ±1μm, the chip pressing speed is 0.2-0.5mm / s, the speed is reduced to 0.05mm / s at the moment of contact, and the contact pressure is 5-10N.

[0009] A further implementation scheme of the present invention is that in step S5, the suction nozzle moves using an S-shaped acceleration and deceleration curve, with a maximum acceleration of 0.5m / s² and a final Z-axis bonding speed of 0.05-0.1mm / s. The protective film contacts the silver paste 10-20ms before the chip, and the pressure difference between the two sides is controlled to ≤2N. The suction nozzle is equipped with an active vibration reduction module, and the amplitude during movement is ≤1μm.

[0010] A further implementation scheme of the present invention is that in step S7, the sintering equipment adopts zoned temperature control, the main heating zone is resistance heating, the edge compensation is infrared heating, the temperature control accuracy is ±2°C, the pressure loading increases linearly from 10kg to 40kg with increasing temperature, the pressure head has a built-in strain gauge feedback, and the sintering atmosphere is nitrogen or formic acid reducing atmosphere.

[0011] A further implementation scheme of the present invention is that in step S8, the main heating zone and edge compensation are used for coordinated temperature control during the insulation stage, the temperature difference on the substrate surface is ≤2°C, the insulation time is dynamically adjusted according to the thickness of the silver paste, and is increased by 0.5 minutes for every 10μm of thickness. It is calibrated in real time by an infrared thermometer, and the nano silver paste is kept at 250°C for 1-3 minutes.

[0012] A further embodiment of the present invention is that in step S9, the protective film is peeled off by thermal release, and after heating to 180-220°C, it is peeled off at a uniform speed of 45° at a speed of 5-10 mm / s, and argon plasma cleaning is used after peeling.

[0013] The beneficial effects of the present invention are: By integrating pre-sintering and sintering functions into a single device, dual vacuum pipeline nozzles are used to achieve synchronous adsorption and precise positioning of the protective film and chip. Combined with optimized temperature, pressure control and dynamic adjustment technology, the production cycle of the sintering process is significantly shortened, and the accuracy and reliability of the interconnection between the chip and the ceramic substrate are improved. At the same time, through innovative designs such as zoned temperature control, dynamic pressure loading and thermal release and peeling of the protective film, problems such as high equipment cost, inability to accurately apply pressure to a single chip, and limited application of the protective film in traditional processes are solved, and an efficient, low-cost, and highly consistent sintering process is achieved, which is particularly suitable for the manufacture of power modules with small chip spacing and high-density integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0015] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0016] In the description of this application, it should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the exemplary embodiments according to this application. For ease of description, the dimensions of the various parts shown in the drawings are not drawn according to the actual proportional relationship. Technologies, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the technologies, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0017] It should be noted that the terms "first," "second," etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than those illustrated or described herein, and that the objects distinguished by "first," "second," etc. are generally of the same type, and do not limit the number of objects. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0018] It should be noted that, in the description of this application, the directions or positional relationships indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise specified, these directional terms do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of this application; the directional terms "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0019] It should be noted that, in the present application, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0020] This embodiment provides a sintering process for a chip and a ceramic substrate, comprising the following steps: S1 provides a ceramic substrate, and coated with silver paste on its surface to form a uniform silver paste layer; S2 provides a nozzle with dual vacuum lines, wherein the first vacuum line adsorbs the protective film through a circular opening, and the second vacuum line adsorbs the chip through an X-shaped slot or other shaped slot; S3. Controlling the first vacuum line of the nozzle to open, adsorbing the protective film, and positioning it to a predetermined area of ​​the ceramic substrate; S4. Control the second vacuum line of the suction nozzle to open, adsorb the chip, and adjust its position so that the back of the chip contacts the silver paste layer. Move the suction nozzle with the chip and protective film adsorbed to the top of the ceramic substrate so that the chip and protective film are simultaneously attached to the surface of the silver paste layer; S,5. Apply constant temperature and pressure through the nozzle, where the temperature is controlled at 200-250°C and the pressure is controlled at 30-40kg, so that the silver paste forms metal atom migration conditions between the back of the chip and the ceramic substrate; S6. Maintain the sintering temperature and time for 1-5 minutes to ensure that the silver paste is fully sintered and forms a stable interconnected structure; S7. After sintering is completed, the protective film is removed to obtain the interconnection structure between the chip and the ceramic substrate.

[0021] A further embodiment of the present invention is that in step S1, the surface of the ceramic substrate is plasma cleaned or ultrasonically cleaned, and the surface energy is ≥50 mN / m. The silver paste is applied by screen printing, the screen mesh is 200-300 mesh, the printing thickness is 10-50 μm, and the surface roughness Ra after leveling is ≤2 μm. The silver paste contains nanosilver particles and glass powder, and the glass powder accounts for 0.1-1wt%. After the silver paste is applied, it is preheated at 50-80°C for leveling for 1-5 minutes, and the thickness tolerance is monitored online by a laser thickness gauge to within ±3 μm. Specifically, the ceramic substrate is plasma cleaned (using an argon / oxygen mixed gas, 500W power for 60 seconds) or ultrasonically cleaned (950kHz frequency, 40°C cleaning solution for 180 seconds) to increase its surface energy to ≥50mN / m; then, a 200-300 mesh screen printing screen is used to coat a nano-silver paste containing 0.1-1wt% glass powder, and the printing thickness is controlled to be 10-50μm. The coated substrate is placed on a 50-80°C hot plate for leveling for 1-5 minutes to reduce the surface roughness of the silver paste to Ra≤2μm. At the same time, a laser thickness gauge is used to monitor the thickness fluctuation in real time to ensure that the uniformity of the silver paste layer meets the sintering requirements.

[0022] A further embodiment of the present invention is that in the step S2, the first vacuum line of the suction nozzle is a circular hole array with a hole diameter of 0.3-0.8mm, and the opening area accounts for 30-50% of the bottom surface of the suction nozzle; the second vacuum line is an X-shaped or radial slot with a slot width of 0.1-0.5mm and a depth of 0.2-0.5mm. The internal channel diameters of the first vacuum line and the second vacuum line are 2-3mm and 1-2mm respectively, and are connected to independent vacuum pump systems. The suction nozzle is made of silicon carbide or zirconia ceramic. Specifically, the suction nozzle is made of silicon carbide or zirconia ceramic material, and its bottom surface design includes two independent vacuum systems: the first vacuum line is composed of a circular hole array with a diameter of 0.3-0.8mm, the total opening area accounts for 30-50% of the bottom surface of the suction nozzle, and the internal channel diameter is 2-3mm; the second vacuum line adopts an X-shaped or radial slot structure with a slot width of 0.1-0.5mm, a depth of 0.2-0.5mm, and an internal channel diameter of 1-2mm. The two sets of pipelines are connected to independently controlled vacuum pump systems. Through precision processing, the first pipeline is used for protective film adsorption (the circular hole array provides uniform adsorption force), and the second pipeline is used for chip grasping (the slotted structure adapts to the chip shape), realizing dual-function synchronous operation.

[0023] A further implementation scheme of the present invention is that in step S3, the opening of the first vacuum line is controlled by a solenoid valve, with a response time of ≤10ms, a vacuum degree of 0.05-0.1MPa, and an adsorption force of 5-10N. The protective film is made of polyimide, with a thickness of 20-100μm, a pre-cut size 0.5-1mm larger than the chip, and the release paper is automatically removed by a peeling roller before adsorption. The positioning uses a visual system to identify the substrate mark and the edge of the protective film. Specifically, the opening of the first vacuum line is accurately controlled by a high-speed solenoid valve to establish a vacuum degree of 0.05-0.1MPa and generate a 5-10N adsorption force; a polyimide protective film with a thickness of 20-100μm is used, and after the release paper is automatically peeled off by the peeling roller, the suction nozzle adsorbs the protective film through a circular hole array; at the same time, the visual system recognizes the positioning marks on the ceramic substrate and the edge features of the protective film in real time, and cooperates with the motion control system to achieve ±1μm accuracy of alignment to ensure that the protective film accurately covers the predetermined area.

[0024] A further implementation scheme of the present invention is that in step S4, the opening delay of the second vacuum pipeline is 50-100ms, the vacuum degree is 0.1-0.2MPa, the adsorption force is 10-20N, and the vacuum degree is dynamically adjusted according to the chip size. Before the chip is adsorbed, the back electrode is identified by the upward camera, and the silver paste layer is photographed by the downward camera. The dual cameras have a collaborative positioning accuracy of ±1μm, the chip pressing speed is 0.2-0.5mm / s, the speed is reduced to 0.05mm / s at the moment of contact, and the contact pressure is 5-10N. After the protective film is attached, the system delays 50-100ms before activating the second vacuum line. A closed-loop controlled vacuum generator precisely adjusts the vacuum level to 0.1-0.2MPa. A high-precision upward-looking camera scans the electrode pattern on the backside of the chip, while a downward-looking camera captures the topography of the silver paste layer. The dual-vision system uses a feature matching algorithm to achieve coordinated positioning with an accuracy of ±1μm. The nozzle presses down at an initial speed of 0.2-0.5mm / s, triggering a deceleration sequence when the chip is 100μm from the silver paste layer. Finally, the contact is completed at a contact speed of 0.05mm / s. Real-time feedback from a pressure sensor ensures a contact pressure of 5-10N, creating a damage-free initial connection. The nozzle moves using an S-shaped acceleration and deceleration profile, with a maximum acceleration of 0.5m / s² and a final Z-axis contact speed of 0.05-0.1mm / s. The protective film contacts the silver paste 10-20ms before the chip, and the pressure difference between the two sides is controlled to ≤2N. The nozzle is equipped with an active vibration reduction module, ensuring an amplitude of ≤1μm during movement. Specifically, the suction nozzle executes S-shaped acceleration and deceleration curve movement through a high-precision motion control system, with the maximum acceleration strictly controlled at 0.5m / s². The Z-axis adopts closed-loop servo control to achieve a final bonding speed of 0.05-0.1mm / s. The system uses timing control to make the protective film contact the silver paste layer 10-20ms in advance, and uses high-sensitivity pressure sensors (resolution 0.1N) integrated on both sides of the suction nozzle for real-time monitoring. The vacuum adsorption force is dynamically adjusted through the PID algorithm to ensure that the pressure difference between the two sides is ≤2N. At the same time, the active vibration reduction module built into the suction nozzle actively offsets vibration at a response frequency of 1kHz, ensuring that the amplitude of the entire movement process is ≤1μm, thereby achieving smooth and precise bonding between the protective film and the chip.

[0025] A further embodiment of the present invention is that in step S5, the suction nozzle is connected to the sintering equipment for heating. The sintering equipment adopts zoned temperature control, with the main heating zone being resistance heating and the edge compensation being infrared heating. The temperature control accuracy is ±2°C, and the pressure load increases linearly from 10kg to 40kg with increasing temperature. The pressure head has built-in strain gauge feedback, and the sintering atmosphere is a nitrogen or formic acid reducing atmosphere. The sintering equipment achieves precise heating through a multi-zone coordinated temperature control system: the main heating zone uses a PID-controlled resistance heater, and the edge area is equipped with an infrared compensation heater. Real-time feedback is provided by five K-type thermocouples distributed on the substrate, combined with a fuzzy control algorithm to maintain the overall temperature control accuracy within ±2°C. The pressure system is driven by a servo electric cylinder, achieving a linear pressure increase of 10-40kg based on the temperature sensor signal. The strain gauge embedded in the pressure head monitors the actual pressure value in real time and provides feedback correction. At the same time, nitrogen or formic acid vapor is introduced into the equipment cavity, and a constant airflow of 20L / min is maintained by a mass flow controller to form a uniform reducing sintering atmosphere.

[0026] A further implementation scheme of the present invention is that in the step S6, the main heating zone and edge compensation are used for coordinated temperature control during the insulation stage, the temperature difference on the substrate surface is ≤2°C, the insulation time is dynamically adjusted according to the thickness of the silver paste, and 0.5 minutes are added for every 10μm of thickness, and the nano silver paste is calibrated in real time at 250°C for 1-3 minutes. Specifically, the system ensures that the temperature difference on the substrate surface is ≤2°C during the entire insulation stage through the coordinated control of the main heating zone resistance heating and edge infrared compensation, combined with the 7-point thermocouple array arranged on the substrate surface and the real-time temperature feedback of the infrared thermal imager; the control system dynamically adjusts the insulation time of 1-3 minutes within the constant temperature range of 250°C according to the silver paste thickness pre-detected by the laser thickness gauge, and performs temperature calibration every 10 seconds through the two-color infrared thermometer to ensure that the nano silver paste completes the metal atom migration conditions in the optimal sintering window.

[0027] A further embodiment of the present invention is that in step S7, the protective film is peeled off by thermal release, heated to 180-220°C, and then peeled off at a uniform speed of 5-10mm / s at a 45° angle. After peeling, argon plasma cleaning is used. Specifically, the system uses an infrared heater to precisely heat the protective film area to 180-220°C. After the heat-sensitive adhesive layer softens, the edge of the protective film is clamped by a robotic arm and peeled off at a uniform speed of 5-10mm / s at a 45° angle. After peeling, argon plasma cleaning is immediately started, and the plasma is excited by an RF power supply to effectively remove residual organic matter on the surface of the silver paste, so that the interconnect interface reaches atomic-level cleanliness.

[0028] Through the above implementation content, by integrating pre-sintering and sintering functions into a single device, using dual vacuum pipeline suction nozzles to achieve synchronous adsorption and precise positioning of the protective film and chip, combined with optimized temperature, pressure control and dynamic adjustment technology, the production cycle of the sintering process is significantly shortened, and the accuracy and reliability of the interconnection between the chip and the ceramic substrate are improved; at the same time, through innovative designs such as zoned temperature control, dynamic pressure loading and thermal release and peeling of the protective film, the problems of high equipment cost, inability to accurately apply pressure to a single chip, and limited application of the protective film in the traditional process are solved, and an efficient, low-cost, and highly consistent sintering process is achieved, which is particularly suitable for the manufacture of power modules with small chip spacing and high-density integration.

[0029] The embodiments of the present application are described above in conjunction with the accompanying drawings. Unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A sintering process for a chip and a ceramic substrate, characterized in that: The following steps are involved: S1 provides a ceramic substrate, and coated with silver paste on its surface to form a uniform silver paste layer; S2 provides a nozzle with dual vacuum lines, wherein the first vacuum line adsorbs the protective film through a circular opening, and the second vacuum line adsorbs the chip through an X-shaped slot or other shaped slot; S3. Controlling the first vacuum line of the nozzle to open, adsorbing the protective film, and positioning it to a predetermined area of ​​the ceramic substrate; S4. Control the second vacuum line of the suction nozzle to open, adsorb the chip, and adjust its position so that the back of the chip contacts the silver paste layer. Move the suction nozzle with the chip and protective film adsorbed to the top of the ceramic substrate so that the chip and protective film are simultaneously attached to the surface of the silver paste layer; S5. Apply constant temperature and pressure through the nozzle, wherein the temperature is controlled at 200-250°C and the pressure is controlled at 30-40kg, so that the silver paste forms metal atom migration conditions with the back of the chip and the ceramic substrate; S6. Maintain the sintering temperature and time for 1-5 minutes to ensure that the silver paste is fully sintered and forms a stable interconnected structure; S7. After sintering is completed, the protective film is removed to obtain the interconnection structure between the chip and the ceramic substrate.

2. The sintering process of a chip and a ceramic substrate according to claim 1, characterized in that: In step S1, the surface of the ceramic substrate is plasma cleaned or ultrasonically cleaned, and the surface energy is ≥50 mN / m. The silver paste is applied by screen printing, the screen mesh is 200-300 mesh, the printing thickness is 10-50 μm, and the surface roughness Ra after leveling is ≤2 μm. The silver paste contains nanosilver particles and glass powder, and the glass powder accounts for 0.1-1 wt%. After the silver paste is applied, it is preheated at 50-80° C. for leveling for 1-5 minutes, and the thickness tolerance is monitored online by a laser thickness gauge to within ±3 μm.

3. The sintering process of a chip and a ceramic substrate according to claim 2, characterized in that: In step S2, the first vacuum pipeline of the suction nozzle is a circular hole array with a hole diameter of 0.3-0.8mm, and the opening area accounts for 30-50% of the bottom surface of the suction nozzle; the second vacuum pipeline is an X-shaped or radial groove with a groove width of 0.1-0.5mm and a depth of 0.2-0.5mm. The internal channel diameters of the first vacuum pipeline and the second vacuum pipeline are 2-3mm and 1-2mm respectively, and they are connected to independent vacuum pump systems. The suction nozzle is made of silicon carbide or zirconium oxide ceramics.

4. The sintering process of a chip and a ceramic substrate according to claim 3, characterized in that: In step S3, the opening of the first vacuum line is controlled by a solenoid valve, the response time is ≤10ms, the vacuum degree is 0.05-0.1MPa, the adsorption force is 5-10N, the protective film is made of polyimide material, the thickness is 20-100μm, the pre-cut size is 0.5-1mm larger than the chip, and the release paper is automatically removed by the peeling roller before adsorption. The positioning uses a visual system to identify the substrate mark and the edge of the protective film.

5. The sintering process of a chip and a ceramic substrate according to claim 4, characterized in that: In step S4, the opening delay of the second vacuum pipeline is 50-100ms, the vacuum degree is 0.1-0.2MPa, the adsorption force is 10-20N, and the vacuum degree is dynamically adjusted according to the chip size. Before the chip is adsorbed, the back electrode is identified by the upward camera, and the silver paste layer is photographed by the downward camera. The collaborative positioning accuracy of the two cameras is ±1μm. The chip pressing speed is 0.2-0.5mm / s, and the speed is reduced to 0.05mm / s at the moment of contact. The contact pressure is 5-10N. In step S5, the nozzle movement adopts an S-shaped acceleration and deceleration curve, with a maximum acceleration of 0.5m / s² and a final Z-axis bonding speed of 0.05-0.1mm / s. The protective film contacts the silver paste 10-20ms before the chip, and the pressure difference between the two sides is controlled at ≤2N. The nozzle is equipped with an active vibration reduction module, and the amplitude during movement is ≤1μm.

6. The sintering process of a chip and a ceramic substrate according to claim 5, characterized in that: In step S5, the sintering equipment adopts zoned temperature control, the main heating zone is resistance heating, the edge compensation is infrared heating, the temperature control accuracy is ±2°C, the pressure load increases linearly from 10kg to 40kg as the temperature rises, the pressure head has a built-in strain gauge feedback, and the sintering atmosphere is nitrogen or formic acid reducing atmosphere.

7. The sintering process of a chip and a ceramic substrate according to claim 6, characterized in that: In step S6, the main heating zone and edge compensation are used for coordinated temperature control during the insulation stage, the temperature difference on the substrate surface is ≤2°C, the insulation time is dynamically adjusted according to the thickness of the silver paste, and is increased by 0.5 minutes for every 10 μm of thickness. The nano silver paste is calibrated in real time by an infrared thermometer, and is kept at 250°C for 1-3 minutes.

8. The sintering process of a chip and a ceramic substrate according to claim 7, characterized in that: In step S7, the protective film is peeled off by thermal release, and after being heated to 180-220° C., it is peeled off at a constant speed of 45° and 5-10 mm / s, and is cleaned by argon plasma after peeling.

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