Thermocompression bonding system and bonding method in wide-range pressure range

Abstract

The invention belongs to the technical field of wafer bonding, and particularly relates to a thermocompression bonding system and bonding method in a wide-range pressure range. The hot-pressing bonding system with the wide pressure range comprises a bonding device, the bonding device is respectively connected with a pressurization system, a vacuumizing system and a vacuum breaking system, the bonding device comprises an upper heating disc and a lower heating disc below the upper heating disc, and quartz heating pipes are embedded in the upper heating disc and the lower heating disc. The pressurization system comprises a plurality of electric proportional valves, the input ends of the electric proportional valves are connected with a gas source, the output ends of the electric proportional valves are correspondingly connected with fluid pressure conversion devices with different gas-liquid pressure conversion ratios, the fluid pressure conversion devices are connected with a pressure output mechanism, and the pressure output mechanism is connected with the gas source. The output force of the pressure output mechanism ranges from 0 KN to 150 KN. Through collaborative innovation of multiple systems, high precision, high efficiency and high reliability of the wafer bonding process are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of wafer bonding, and in particular relates to a hot-compression bonding system and a bonding method with a large pressure range. Background Art

[0002] In modern semiconductor manufacturing and electronic component processing, wafer bonding is a critical process step, and its quality directly affects the performance and reliability of the final product. During the wafer bonding process, the performance of the heating plate is crucial, especially in terms of heating uniformity, temperature control accuracy, heating rate, and energy consumption. However, the heat source of the commonly used heating plate is usually a disc-shaped heating wire, which has the following limitations: Poor heating uniformity: Disc heating wires are usually arranged in a spiral or circuitous shape, which makes it difficult to achieve completely uniform temperature distribution. Especially when heating a large area, the temperature in the edge area is usually lower than that in the center area, resulting in uneven heating of the wafer.

[0003] Slow heating rate: The heating rate of the disc heating wire is slow and the efficiency is low, which makes it difficult to meet the demand for rapid heating.

[0004] Difficulty in zoned heating: Disc heating wires are difficult to achieve zoned heating and cannot be precisely controlled according to the needs of different areas.

[0005] High energy consumption: Traditional heating wires require high energy input to reach the required temperature, and the energy utilization rate is low.

[0006] Furthermore, in industrial production, especially in processes such as thermocompression bonding, stamping, and molding, traditional pressure output devices typically operate only within a limited pressure range, making it difficult to meet diverse demands from low to high pressures. For example, some equipment may require pre-pressing at low pressure and final molding or stamping at high pressure. Existing equipment often operates only within a single pressure range and cannot achieve a full range of pressure output. Furthermore, these devices also have shortcomings in control accuracy and response speed, making it difficult to meet the high-precision and fast-response requirements of modern industrial production.

[0007] Therefore, there is an urgent need for a device that can achieve a wide range of pressure outputs. This device should not only provide precise control in different pressure ranges, but also have efficient energy conversion, fast response, and a compact structural design. At the same time, a heating plate structure that can solve the problem of uneven heating is also needed to improve the quality and efficiency of wafer bonding. Summary of the Invention

[0008] In view of the above shortcomings of the prior art, an object of the present invention is to provide a thermal compression bonding system and bonding method with a wide range of pressures.

[0009] In order to achieve the above objectives, the technical solutions adopted are: One of the objects of the present invention is to provide a hot pressing bonding system with a large pressure range, comprising a bonding device, wherein the bonding device is respectively connected to a pressurizing system, a vacuum pumping system and a vacuum breaking system, the bonding device comprises a bonding chamber, the bonding chamber is provided with an upper heating plate and a lower heating plate below, and the upper heating plate and the lower heating plate are both embedded with multiple quartz heating tubes; the pressurizing system comprises an electric proportional valve, the input end of the electric proportional valve is connected to the gas source, the electric proportional valve is arranged in plurality, and the output end of each of the electric proportional valves is correspondingly connected to a fluid pressure conversion device with a different gas-liquid pressure conversion ratio, the fluid pressure conversion device is connected to a pressure output mechanism, and the output force range of the pressure output mechanism is 0-150KN.

[0010] Preferably, the number of the electrical proportional valves is three, and the output ends of the three electrical proportional valves correspond to three fluid pressure conversion devices with different gas-liquid pressure conversion ratios, and the gas-liquid pressure conversion ratios of the three fluid pressure conversion devices are 1:1, 1:3 and 1:12 respectively.

[0011] The beneficial effects of adopting the above-mentioned preferred technical solution are: setting three electrical proportional valves and correspondingly connecting fluid pressure conversion devices with different gas-liquid pressure conversion ratios, so that the system can select the appropriate conversion device according to different pressure requirements, further improving the flexibility and control accuracy of the system. At the same time, by rationally allocating conversion devices in different pressure range segments, the overall performance of the system is optimized, so that it can operate efficiently in different pressure segments; a conversion ratio of 1:1 means that air pressure is directly converted into hydraulic pressure, which is suitable for low pressure ranges (such as 0-14KN), can respond quickly and provide stable output. A gas-liquid pressure conversion ratio of 1:3 is suitable for medium pressure ranges (such as 14-40KN) and can provide moderate output force. A gas-liquid pressure conversion ratio of 1:12 can convert lower air pressure into higher hydraulic pressure, which is suitable for occasions requiring large output force, such as the pressure range of 40-150KN.

[0012] Preferably, the pressure output mechanism comprises a hydraulic cylinder, one end of the hydraulic cylinder is a piston rod, and the piston rod end is the pressure output end.

[0013] Preferably, the other end of the hydraulic cylinder is connected to a lifting cylinder.

[0014] The beneficial effects of adopting the above preferred technical solution are: the hydraulic cylinder, as a pressure output mechanism, can convert hydraulic energy into mechanical energy, achieving stable force output. The piston rod, as the pressure output end, can be directly connected to external equipment, facilitating various mechanical operations such as pressing and pushing, thereby improving the practicality and operational convenience of the system. The hydraulic cylinder piston rod extends under the action of hydraulic oil pressure, but there is no corresponding hydraulic oil circuit to retract the piston rod. Therefore, an air cylinder is added to assist in retracting the hydraulic cylinder piston rod.

[0015] Preferably, the fluid pressure conversion device is an air-oil booster or a gas-liquid converter.

[0016] The beneficial effect of adopting this preferred technical solution is that the fluid pressure conversion device uses either an air-oil booster or a gas-to-liquid converter. These two devices can be selected based on different application scenarios and pressure requirements, providing a diverse solution. The air-oil booster can achieve a high pressure increase and is suitable for applications requiring high-pressure output. The gas-to-liquid converter is suitable for medium and low pressure ranges and features a simple structure and fast response, further enriching the system's functionality and applicability.

[0017] Preferably, the fluid pressure conversion devices with gas-liquid pressure conversion ratios of 1:1, 1:3 and 1:12 respectively are a gas-liquid converter, a first air-oil booster and a second air-oil booster, which are respectively connected to a first electrical proportional valve, a second electrical proportional valve and a third electrical proportional valve, that is, the first electrical proportional valve is connected to the gas-liquid converter, the second electrical proportional valve is connected to the first air-oil booster, and the third electrical proportional valve is connected to the second air-oil booster. The output end of the first air-oil booster is connected to a first pipeline, and the output end of the second air-oil booster is connected to a second pipeline. The first pipeline and the second pipeline are commonly connected to a three-way valve for oil, and the three-way valve for oil is also connected to a third pipeline, and the third pipeline is connected to the pressure output mechanism.

[0018] The beneficial effect of adopting the above preferred technical solution is that the structure of the three-way valve makes it possible to switch different air-oil boosters as needed to achieve outputs in different pressure ranges.

[0019] More preferably, the output end of the gas-liquid converter is connected to an oil manifold, which is respectively connected to the first pipeline and the second pipeline. The gas-liquid converter enters the oil through the oil manifold through the first pipeline or the second pipeline and is connected to the third pipeline through the three-way valve.

[0020] Preferably, the oil manifold is connected to the first pipeline via the output end of the first air-oil supercharger, and the oil manifold is connected to the second pipeline via the output end of the second air-oil supercharger.

[0021] The beneficial effect of adopting the above-mentioned preferred technical solution is that the hydraulic oil output from the output end of the gas-liquid converter only flows through the output end of the air-oil booster through the oil manifold, flows into the oil three-way valve through the first pipeline or the second pipeline, and enters the pressure output mechanism through the third pipeline. The amplifying effect of the air-oil booster is not used. The amplifying effect of the air-oil booster requires the air supply of the electrical proportional valve to be realized. Therefore, in the output from the gas-liquid converter, the air-oil booster only plays the role of providing a pipeline.

[0022] Preferably, the quartz heating tube is a long strip structure, and a plurality of the quartz heating tubes are arranged in parallel.

[0023] The beneficial effects of adopting the above technical solution are: the quartz heating tube is heated by infrared radiation, which can quickly and evenly transfer heat to the heating plate. This heating method can achieve a very uniform temperature distribution. Multiple quartz heating tubes are arranged in parallel, which can further provide uniform heat distribution and ensure uniform temperature in the heating plate; the quartz heating tube has efficient thermal conductivity, can quickly heat up, and improve heating efficiency.

[0024] Preferably, the quartz heating tubes in the upper heating plate and the lower heating plate are arranged correspondingly up and down.

[0025] The beneficial effect of adopting the above-mentioned preferred technical solution is that the corresponding upper and lower quartz heating tubes can ensure symmetrical heat distribution between the upper and lower heating plates, further improving the uniformity of heating.

[0026] More preferably, the quartz heating tube passes through both ends of the upper heating plate or the lower heating plate.

[0027] The beneficial effect of adopting the above-mentioned preferred technical solution is that the quartz heating tubes arranged throughout can more effectively transfer heat to various parts of the heating plate, thereby improving the heat conduction efficiency.

[0028] Preferably, four quartz heating tubes are provided in each of the upper heating plate and the lower heating plate.

[0029] Preferably, a wafer pair is provided between the upper heating plate and the lower heating plate.

[0030] Preferably, a mold pair is provided between the upper heating plate and the lower heating plate, including an upper mold and a lower mold, and graphite pads are provided above and below the wafer pair, and the graphite pad and the wafer pair are located between the upper mold and the lower mold.

[0031] The beneficial effects of adopting the above-mentioned preferred technical solution are: the graphite pad can protect the wafer from direct contact with the mold and reduce damage; the mold pair can provide uniform pressure to ensure that the wafer maintains good contact and pressure distribution during the bonding process, thereby achieving alignment of the two wafers.

[0032] Preferably, the mold pair is provided with a groove adapted to the structure of the graphite pad and wafer pair.

[0033] The beneficial effect of adopting the above preferred technical solution is that the groove is used to position the graphite pad and the wafer pair, reducing displacement during the heating process.

[0034] Preferably, an upper cold plate is connected above the upper heating plate, and a lower cold plate is connected below the lower heating plate. Cooling water pipes are provided in the upper and lower cold plates, and cooling water inlets and cooling water outlets are provided correspondingly in the upper and lower cold plates, that is, the upper cold plate is provided with an upper cold plate cooling water inlet and an upper cold plate cooling water outlet, and the lower cold plate is provided with a lower cold plate cooling water inlet and a lower cold plate cooling water outlet.

[0035] More preferably, the cooling water pipe is embedded in the upper cold plate and the lower cold plate along a wavy path.

[0036] The beneficial effects of adopting the above preferred technical solution are: the cold plate can be quickly cooled by circulating water, thereby improving cooling efficiency, and the cold plate can effectively control the temperature of the heating plate to prevent overheating.

[0037] Preferably, hooks are connected between the upper heating plate and the upper cold plate, and between the lower heating plate and the lower cold plate.

[0038] The beneficial effect of adopting the above preferred technical solution is that the hook can ensure a stable connection between the cold plate and the heating plate, prevent displacement during operation, facilitate installation and removal of the cold plate and the heating plate, and improve maintenance efficiency.

[0039] Preferably, one end of the hook is connected to the upper heating plate, and the other end is connected to the upper cold plate via a screw, and a compression spring is provided on the outer sleeve of the screw.

[0040] Preferably, one end of the hook is connected to the lower heating plate, and the other end is connected to the lower cold plate via a screw, and a compression spring is provided on the outer sleeve of the screw.

[0041] The beneficial effect of adopting the above-mentioned preferred technical solution is that the heating plate produces a slight deformation due to thermal expansion and contraction during the heating process. In order to prevent the screw from falling off due to repeated tension, the compression spring absorbs part of the force through deformation, thereby protecting the screw.

[0042] Preferably, the upper mold and the lower mold are connected by positioning pins.

[0043] Preferably, a positioning groove is provided at the bottom end of the lower mold, and a positioning protrusion adapted to the positioning groove structure is provided on the lower heating plate for positioning the lower mold.

[0044] Preferably, the upper cold plate is connected to the pressure output end.

[0045] Preferably, the bonding chamber is connected to a vacuum pumping system and a vacuum breaking system.

[0046] The beneficial effects of adopting the above-mentioned preferred technical solution are: the bonding chamber provides a carrier for the bonding of wafers, a closed-loop environmental control system is constructed, and the vacuum system can vacuum the bonding chamber; the vacuum breaking system restores the air pressure through nitrogen in a controllable manner to avoid sudden changes in air pressure from damaging the wafer microstructure.

[0047] Preferably, the vacuum pumping system includes a butterfly valve, a dry pump and a molecular pump connected in sequence.

[0048] More preferably, the bonding chamber is connected to the butterfly valve through a pipeline, and the end of the butterfly valve away from the bonding chamber is connected to the dry pump through two branches, wherein one branch is a plug-in valve, a molecular pump, a front-stage vacuum gauge, and a front-stage angle valve connected in sequence, and the other branch is provided with a pipeline angle valve, and the pipeline between the bonding chamber and the butterfly valve is connected in sequence through a pipeline to a vacuum gauge angle valve and a vacuum gauge.

[0049] The beneficial effect of adopting the above-mentioned preferred technical solution is: adopting a two-stage exhaust scheme of dry pump + molecular pump, taking into account both the pumping speed and the ultimate vacuum degree. The dual-branch design allows: branch 1 (gate valve + molecular pump) to achieve high vacuum; branch 2 (pipeline angle valve directly connected to the dry pump) to quickly pre-extract the molecular pump's foreline. The vacuum gauge angle valve remains open by default to monitor the chamber vacuum degree in real time. When the chamber pressure is detected to be low, the vacuum gauge angle valve is closed to prevent the vacuum gauge from being contaminated or overloaded. The molecular pump needs to reach a certain vacuum degree on both sides to open. This value is provided by both the vacuum gauge and the foreline vacuum gauge. The vacuum on both sides of the molecular pump is provided by the dry pump, so there are two pipelines. The vacuum degree provided by the molecular pump is higher than that provided by the dry pump.

[0050] Preferably, the vacuum breaking system comprises a diaphragm valve, a pressure gauge and a pressure reducing valve which are sequentially connected via pipelines, and the pressure reducing valve is connected to a nitrogen source.

[0051] The beneficial effect of adopting the above-mentioned preferred technical solution is that: through the coordinated control of the pressure reducing valve and the diaphragm valve, the vacuum breaking rate can be adjusted, the pressure gauge is specifically a digital pressure gauge, and real-time feedback ensures process controllability.

[0052] Preferably, the bonding chamber is connected to a process vacuum gauge.

[0053] The beneficial effects of adopting the above-mentioned preferred technical solution are: the vacuum gauge connected to the vacuum gauge angle valve is a full-range vacuum gauge with low precision; the process vacuum gauge has a small range but high precision and is used during the process to monitor the vacuum degree of the bonding chamber.

[0054] The second purpose of the present invention is to provide a hot pressing bonding method with a large pressure range, which adopts the hot pressing bonding system with a large pressure range, including the following steps: the bonding chamber is opened, the wafer mold is placed between the heating plate and the lower heating plate, and the bonding chamber is closed; the dry pump, molecular pump and butterfly valve of the vacuum system cooperate to control the vacuum degree of the bonding chamber to reach the process vacuum degree; the pressurizing system controls the hydraulic cylinder to extend, drives the upper heating plate to descend, and controls the hydraulic cylinder to output the process pressure through the electrical proportional valve to complete the pressurization; the upper heating plate and the lower heating plate heat up the wafer mold to reach the process temperature, and complete the hot pressing bonding of the wafer pair after insulation; the upper heating plate and the lower heating plate assembly are heated and closed, and after the temperature drops to room temperature, the lifting cylinder retracts, drives the upper heating plate to rise, and the vacuum breaking system breaks the vacuum of the bonding chamber to atmospheric pressure, the bonding chamber is opened, and the wafer mold is taken out to complete the entire bonding process.

[0055] Preferably, the output force range of 0-150KN is divided into three range segments: 0-14KN, 14-40KN, and 40-150KN, and the three range segments are controlled by the first electrical proportional valve, the third electrical proportional valve, and the second electrical proportional valve respectively.

[0056] The beneficial effects of adopting the above-mentioned preferred technical solution are: through segmented control, each electric proportional valve can accurately control the corresponding pressure range, thereby improving the control accuracy of the system; different pressure sections are realized by different electric proportional valve and booster combinations, ensuring that the system can operate efficiently under different pressures; segmented control can avoid excessive load on a single booster at the full range, thereby improving the stability and service life of the system.

[0057] Preferably, the pressure range of the output ends of the first electrical proportional valve, the third electrical proportional valve and the second electrical proportional valve is 0-0.8 MPa.

[0058] Compared with the prior art, the present invention has the following beneficial effects: The hot pressing bonding system of the present invention achieves high precision, high efficiency and high reliability in the wafer bonding process through the collaborative innovation of multiple systems. The system adopts a two-stage exhaust design of dry pump and molecular pump, which can quickly establish a high vacuum environment, and cooperates with the dynamic protection vacuum gauge angle valve and butterfly valve adjustment to ensure that the exhaust process is stable and reliable. The three-speed gas-liquid conversion pressure system is combined with the infrared radiation heating technology of the quartz heating tube, which shortens the time of the whole process and can achieve a larger pressure output, up to 150KN, which basically meets the pressure output of all hot pressing bonding aspects; the full range of 0-150KN is controllable, and the corresponding thrust can be stably output by controlling the gas pressure in the range of 0-0.8MPa; the segmented control method further improves the control accuracy and operation efficiency of the system, making it suitable for a variety of industrial application scenarios. The heating plate structure of the utility model can provide uniform heat distribution and ensure uniform temperature in the heating plate by setting multiple quartz heating tubes in parallel; the quartz heating tube has high thermal conductivity, can heat up quickly, and improve heating efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a structural diagram of a hot-compression bonding system with a wide range of pressures according to the present invention; Figure 2 It is a schematic structural diagram of a pressure output system with a large range of the present invention; Figure 3 It is a front view of the pressure output system with a large range of the present invention; Figure 4 It is the gas and liquid circuit diagram of the structure of the pressure output system of the present invention with a large range; Figure 5 This is a schematic diagram of the structure of a heating plate using a quartz heating tube as a heat source; Figure 6 for Figure 5 Enlarged view of point A in the middle; Figure 7 This is a front view of the heating plate structure using a quartz heating tube as a heat source; Figure 8 A cross-sectional view of a heating plate structure using a quartz heating tube as a heat source; Figure 9 is a cross-sectional view of a die pair and a wafer pair; The accompanying drawings are marked as follows: 1. lifting cylinder; 2. hydraulic cylinder; 3. three-way valve for oil; 4. oil manifold; 5. second air-oil booster; 6. first electrical proportional valve; 7. second electrical proportional valve; 8. third electrical proportional valve; 9. first air-oil booster; 10. gas-liquid converter; 11. pressure output terminal; 12. first pipeline; 13. second pipeline; 14. third pipeline; 25. process vacuum gauge; 50. diaphragm valve; 60. pressure gauge; 70. pressure reducing valve; 80. dry pump; 90. pipeline angle valve; 100. upper cold plate; 110. cooling water inlet of lower cold plate; 111. cooling water outlet of lower cold plate; 112 , upper mold; 113, lower mold; 114, positioning pin; 115, graphite pad; 116, wafer pair; 117, screw; 118, positioning groove; 119, cooling water pipe; 120, bonding chamber; 130, front stage vacuum gauge; 140, molecular pump; 150, plug-in valve; 160, butterfly valve; 170, vacuum gauge; 180, front stage angle valve; 190, vacuum gauge angle valve; 200, lower cold plate; 300, upper heating plate; 400, lower heating plate; 500, quartz heating tube; 600, hook; 700, compression spring; 800, upper cold plate cooling water inlet; 900, upper cold plate cooling water outlet. DETAILED DESCRIPTION

[0060] The present invention is described below with reference to examples, which are only used to explain the present invention and are not used to limit the scope of the present invention.

[0061] refer to Figures 1 to 9 , a hot compression bonding system with a large pressure range includes a bonding device, which is respectively connected to a pressurization system, a vacuum system and a vacuum breaking system, and the bonding device includes a bonding chamber 120, wherein the bonding chamber 120 is provided with an upper heating plate 300 and a lower heating plate 400 below, and multiple quartz heating tubes 500 are embedded in the upper heating plate 300 and the lower heating plate 400, and the pressurization system includes an electric proportional valve, the input end of the electric proportional valve is connected to the gas source, and the electric proportional valve is provided in plurality, and the output end of each of the electric proportional valves is correspondingly connected to a fluid pressure conversion device with a different gas-liquid pressure conversion ratio, and the fluid pressure conversion device is connected to a pressure output mechanism, and the output force range of the pressure output mechanism is 0-150KN.

[0062] As a preferred embodiment, the number of the electrical proportional valves is three, and the output ends of the three electrical proportional valves correspond to three fluid pressure conversion devices with different gas-liquid pressure conversion ratios, and the gas-liquid pressure conversion ratios of the three fluid pressure conversion devices are 1:1, 1:3 and 1:12 respectively.

[0063] As a preferred embodiment, the pressure output mechanism includes a hydraulic cylinder 2 , one end of the hydraulic cylinder 2 is a piston rod, and the piston rod end is the pressure output end 11 .

[0064] As a preferred embodiment, the other end of the hydraulic cylinder 2 is connected to the lifting cylinder 1.

[0065] As a preferred embodiment, the fluid pressure conversion device is an air-oil booster or a gas-liquid converter 10.

[0066] As a preferred embodiment, the fluid pressure conversion devices with gas-liquid pressure conversion ratios of 1:1, 1:3 and 1:12 respectively are a gas-liquid converter 10, a first air-oil booster 9 and a second air-oil booster 5, which are respectively connected to a first electrical proportional valve 6, a second electrical proportional valve 7 and a third electrical proportional valve 8, that is, the first electrical proportional valve 6 is connected to the gas-liquid converter 10, the second electrical proportional valve 7 is connected to the first air-oil booster 9, and the third electrical proportional valve 8 is connected to the second air-oil booster 5. The output end of the first air-oil booster 9 is connected to a first pipeline 12, and the output end of the second air-oil booster 5 is connected to a second pipeline 13. The first pipeline 12 and the second pipeline 13 are jointly connected to an oil three-way valve 3, and the oil three-way valve 3 is also connected to a third pipeline 14, and the third pipeline 14 is connected to the pressure output mechanism.

[0067] As a preferred embodiment, the output end of the gas-liquid converter 10 is connected to the oil manifold 4, and the oil manifold 4 is respectively connected to the first pipeline 12 and the second pipeline 13. The gas-liquid converter 10 enters the oil three-way valve 3 through the oil manifold 4 through the first pipeline 12 or the second pipeline 13 and is connected to the third pipeline 14.

[0068] As a preferred embodiment, the oil manifold 4 is connected to the first pipeline 12 via the output end of the first air-oil booster 9 , and the oil manifold 4 is connected to the second pipeline 13 via the output end of the second air-oil booster 5 .

[0069] As a preferred embodiment, the quartz heating tube 500 is a long strip structure, and a plurality of the quartz heating tubes 500 are arranged in parallel.

[0070] As a preferred embodiment, the quartz heating tubes 500 in the upper heating plate 300 and the lower heating plate 400 are arranged correspondingly in the upper and lower directions.

[0071] In this embodiment, the quartz heating tube 500 passes through both ends of the upper heating plate 300 or the lower heating plate 400 .

[0072] In this embodiment, four quartz heating tubes 500 are disposed in each of the upper heating plate 300 and the lower heating plate 400 .

[0073] In this embodiment, a wafer pair 116 is disposed between the upper heating plate 300 and the lower heating plate 400 .

[0074] As a preferred embodiment, a mold pair is provided between the upper heating plate 300 and the lower heating plate 400, including an upper mold 112 and a lower mold 113, and graphite pads 115 are provided above and below the wafer pair 116. The graphite pad 115 and the wafer pair 116 are located between the upper mold 112 and the lower mold 113.

[0075] As a preferred embodiment, the mold pair is provided with a groove adapted to the structure of the graphite pad 115 and the wafer pair 116 .

[0076] As a preferred embodiment, the upper heating plate 300 is connected to an upper cold plate 100, and the lower heating plate 400 is connected to a lower cold plate 200. Cooling water pipes 119 are provided in both the upper cold plate 100 and the lower cold plate 200. An upper cold plate cooling water inlet 800 and an upper cold plate cooling water outlet 900 are provided corresponding to the upper cold plate 100, and a lower cold plate cooling water inlet 110 and a lower cold plate cooling water outlet 111 are provided in the lower cold plate 200.

[0077] As a preferred embodiment, the cooling water pipe 119 is embedded in the upper cold plate 100 and the lower cold plate 200 along a wavy path.

[0078] As a preferred embodiment, hooks 600 are connected between the upper heating plate 300 and the upper cold plate 100 , and between the lower heating plate 400 and the lower cold plate 200 .

[0079] In this embodiment, one end of the hook 600 abuts against the upper heating plate 300 , and the other end is connected to the upper cold plate 100 via a screw 117 , and a compression spring 700 is provided on the outer sleeve of the screw 117 .

[0080] In this embodiment, one end of the hook 600 abuts against the lower heating plate 400 , and the other end is connected to the lower cold plate 200 via a screw 117 , and a compression spring 700 is provided on the outer sleeve of the screw 117 .

[0081] In this embodiment, the upper mold 112 and the lower mold 113 are connected via a positioning pin 114 .

[0082] In an optional embodiment, a positioning groove 118 is provided at the bottom end of the lower mold 113 , and a positioning protrusion adapted to the structure of the positioning groove 118 is provided on the lower heating plate 400 for positioning the lower mold 113 .

[0083] In this embodiment, the upper cold plate 100 is connected to the pressure output end 11 .

[0084] In this embodiment, the bonding chamber 120 is connected to a vacuum pumping system and a vacuum breaking system.

[0085] In an optional embodiment, the vacuum pumping system includes a butterfly valve 160 , a dry pump 80 , and a molecular pump 140 connected in sequence.

[0086] In an optional embodiment, the bonding chamber 120 is connected to the butterfly valve 160 through a pipeline, and the end of the butterfly valve 160 away from the bonding chamber 120 is connected to the dry pump 80 through two branches, wherein one branch is a plug-in valve 150, a molecular pump 140, a front-stage vacuum gauge 130, and a front-stage angle valve 180 connected in sequence, and the other branch is provided with a pipeline angle valve 90, and the pipeline between the bonding chamber 120 and the butterfly valve 160 is connected in sequence through a pipeline to a vacuum gauge angle valve 190 and a vacuum gauge 170.

[0087] In an optional embodiment, the vacuum breaking system includes a diaphragm valve 50, a pressure gauge 60 and a pressure reducing valve 70 connected in sequence through pipelines, and the pressure reducing valve 70 is connected to a nitrogen source.

[0088] In an optional embodiment, the bonding chamber 120 is connected to a process vacuum gauge 25 .

[0089] The present invention also provides a hot pressing bonding method for the large pressure range, comprising the following steps: the bonding chamber 120 is opened, the wafer mold is placed between the upper heating plate 300 and the lower heating plate 400, and the bonding chamber 120 is closed; the dry pump 80, molecular pump 140 and butterfly valve 160 of the vacuum system cooperate to control the vacuum degree of the bonding chamber 120 to reach the process vacuum degree; the pressurizing system controls the hydraulic cylinder 2 to extend, drives the upper heating plate 300 to descend, and controls the hydraulic cylinder 2 to output the process pressure through the electrical proportional valve to complete the pressurization; the upper heating plate 300 and the lower heating plate 400 heat up the wafer mold to reach the process temperature, and complete the hot pressing bonding of the wafer pair 116 after insulation; the upper heating plate 300 and the lower heating plate 400 components are heated and closed, and after the temperature drops to room temperature, the pulling cylinder 1 retracts, drives the upper heating plate 300 to rise, and the vacuum breaking system breaks the vacuum of the bonding chamber 120 to atmospheric pressure, the bonding chamber 120 is opened, and the wafer mold is taken out to complete the entire bonding process.

[0090] In this embodiment, the output force range of 0-150KN is divided into three range segments: 0-14KN, 14-40KN, and 40-150KN. The three range segments are controlled by the first electrical proportional valve 6, the third electrical proportional valve 8, and the second electrical proportional valve 7 respectively.

[0091] In this embodiment, the pressure range of the output ends of the first electrical proportional valve 6 , the third electrical proportional valve 8 , and the second electrical proportional valve 7 is 0-0.8 MPa.

[0092] Working process of the thermal compression bonding system of the present invention 1. System initialization Chamber preparation: Open the bonding chamber 120, place the aligned wafer mold between the upper heating plate 300 and the lower heating plate 400, and close the chamber to form a sealed environment.

[0093] Vacuum build-up: The vacuum gauge angle valve 190 remains open by default, the dry pump 80 is started, the pipeline angle valve 90 and the front-stage angle valve 180 are opened simultaneously, and the butterfly valve 160 is fully opened to start the roughing process; The dry pump 80 simultaneously evacuates the bonding chamber 120 and the front-stage pipeline of the molecular pump 140. When the vacuum degree of the front-stage pipeline is ≤0.1 mbar, the molecular pump 140 is started; After the molecular pump 140 reaches the rated speed, the gate valve 150 is opened to carry out high vacuum pumping. The ultimate vacuum degree of the system can reach 10 -6 mbar level; The chamber pressure is monitored in real time by the process vacuum gauge 25 and the vacuum gauge 170, and the opening of the butterfly valve 160 is dynamically adjusted to maintain the set vacuum level.

[0094] 2. Bonding process execution Pressure loading: The pressurizing system selects the pressure range (0-14KN / 14-40KN / 40-150KN) according to the process requirements, and the corresponding electric proportional valves 6 / 8 / 7 control the gas-liquid conversion device 10 / 9 / 5 (conversion ratio 1:1 / 1:3 / 1:12) to output hydraulic pressure; The piston rod of hydraulic cylinder 2 extends, pushing the upper heating plate 300, upper cold plate 100 and other components downward to apply pressure, and the pressure value is controlled by the formula F=P×S in a closed loop.

[0095] Heated bonding: The quartz heating tubes 500 in the upper heating plate 300 and the lower heating plate 400 heat up synchronously and quickly reach the set temperature; Wafer bonding is completed under constant temperature and constant pressure conditions, and the holding time is set according to the material properties.

[0096] 3. Process termination and film removal Cooling phase: Turn off the heating system and wait for the chamber temperature to cool naturally to room temperature (cooling can also be accelerated by cooling water pipe 119); The lifting cylinder 1 is actuated to drive the upper heating plate 300, the upper cold plate 100 and other components to reset.

[0097] Breaking the vacuum to take the film: After bonding is completed, the gate valve 150 and the butterfly valve 160 are closed, the diaphragm valve 50 is opened, the pressure reducing valve 70 adjusts the nitrogen input pressure, and the pressure gauge 60 monitors the vacuum breaking rate; After the chamber returns to normal pressure, the chamber is opened and the bonded wafer mold is taken out.

[0098] Specifically, the working process of the pressure loading stage is as follows: when the pressure output mechanism is required to output a pressure of 10KN, the first electrical proportional valve 6 controls the output of a gas pressure of 0.5MPa to the gas-liquid converter 10, and the gas-liquid converter 10 converts the gas pressure into hydraulic oil of corresponding pressure at a ratio of 1:1 for output, and flows through the oil manifold 4 and the second air-oil booster 5 (or the first air-oil booster 9). The oil three-way valve 3 controls the second pipeline 13 corresponding to the second air-oil booster 5 (or the first pipeline 12 corresponding to the first air-oil booster 9) to open the oil circuit, and the hydraulic oil is pressed into the hydraulic cylinder 2 through the third pipeline 14. The inner diameter of the hydraulic cylinder 2 is 160mm. According to F=P*S, where P is pressure, S is the piston area of ​​the hydraulic cylinder 2, and F is thrust, the piston rod end of the pressure output mechanism hydraulic cylinder 2 can output a thrust of about 10KN. The specific calculation process is as follows: ; When the pressure output mechanism is required to output a pressure of 100KN, the second electrical proportional valve 7 controls the output of a gas pressure of about 0.42MPa to the first air-oil booster 9. The first air-oil booster 9 converts the 0.42MPa pressure of the gas into 5.04MPa pressure hydraulic oil for output at a ratio of 1:12. The oil three-way valve 3 controls the opening of the first pipeline 12 corresponding to the first air-oil booster 9. The hydraulic oil is pressed into the hydraulic cylinder 2 through the third pipeline 14. According to F=P*S, P is 5.04MPa and S is 0.0201m 2 , the piston rod end of the hydraulic cylinder 2 of the pressure output mechanism can output a thrust of about 100KN; Similarly, when the pressure output mechanism is required to output a pressure of 30KN, the third electrical proportional valve 8 controls the output of a gas pressure of about 0.5MPa to the second air-oil booster 5. The second air-oil booster 5 converts the 0.5MPa pressure of the gas into 1.5MPa pressure hydraulic oil for output according to the ratio of 1:3. The oil three-way valve 3 controls the opening of the second pipeline 13 corresponding to the second air-oil booster 5. The hydraulic oil is pressed into the hydraulic cylinder 2 through the third pipeline 14. According to F=P*S, P is 1.5MPa and S is 0.0201m 2 The piston rod end of the hydraulic cylinder 2 of the pressure output mechanism can output a thrust of about 30KN.

[0099] During operation, the specific steps involved in heating bonding are as follows: in the chamber preparation stage, a graphite pad 115 is placed in the groove of the lower mold 113, the wafer pair 116 to be bonded is placed in the groove of the lower mold 113, and then covered with another graphite pad 115, and the upper mold 112 and the lower mold 113 are aligned and pressed in by aligning the positioning pins 114. Align the assembled wafer with the mold and press it into the protrusion in the middle of the lower heating plate 400. An electric cylinder is connected to the top of the upper cold plate 100. During the bonding process, the electric cylinder drives the upper cold plate 100, the upper heating plate 300, the quartz heating tube 500 and the hook 600 and other components to descend. After the upper surface of the upper mold 112 contacts the lower surface of the upper heating plate 300, it continues to press down until the process pressure is reached to complete the pressurization of the wafer pair 116. The quartz heating tube 500 is electrically heated and the upper heating plate 300 and the lower heating plate 400 are quickly heated by infrared radiation. After heating to the process temperature, they are kept warm for half an hour. Cooling water is introduced into the upper cold plate cooling water inlet 800 and the lower cold plate cooling water inlet 110 to quickly cool the upper heating plate 300 and the lower heating plate 400 to the set temperature, such as 20°C. The electric cylinder then raises the upper cold platen 100, upper heating platen 300, quartz heating tube 500, and hook 600 components to their initial positions. The mold pair is removed from the lower heating platen 400, the upper mold 112 and graphite pad 115 are opened, and the bonded wafer pair 116 is removed, completing the thermocompression bonding of wafer pair 116. The entire bonding process is simple and fast. The quartz heating tube 500 heats up quickly, achieving a higher heating temperature; the cold plate cools down quickly, shortening the entire process time.

[0100] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A thermal compression bonding system with a wide range of pressures, characterized in that: The invention comprises a bonding device, wherein the bonding device is respectively connected to a pressurizing system, a vacuum pumping system and a vacuum breaking system, wherein the bonding device comprises a bonding chamber (120), wherein an upper heating plate (300) and a lower heating plate (400) are provided in the bonding chamber (120), and a quartz heating tube (500) is embedded in both the upper heating plate (300) and the lower heating plate (400); wherein the pressurizing system comprises an electric proportional valve, wherein the input end of the electric proportional valve is connected to an air source, wherein the electric proportional valve is provided in a plurality, and the output end of each electric proportional valve is correspondingly connected to a fluid pressure conversion device with a different gas-liquid pressure conversion ratio, wherein the fluid pressure conversion device is connected to a pressure output mechanism, and the output force range of the pressure output mechanism is 0-150KN.

2. The wide range thermal compression bonding system according to claim 1, characterized in that: There are three electrical proportional valves, and the output ends of the three electrical proportional valves correspond to three fluid pressure conversion devices with different gas-liquid pressure conversion ratios. The gas-liquid pressure conversion ratios of the three fluid pressure conversion devices are 1:1, 1:3 and 1:12 respectively.

3. The wide range thermal compression bonding system according to claim 1, characterized in that: The pressure output mechanism comprises a hydraulic cylinder (2), one end of the hydraulic cylinder (2) is a piston rod, and the piston rod end is the pressure output end (11).

4. The wide range thermal compression bonding system according to claim 1, characterized in that: The other end of the hydraulic cylinder (2) is connected to the lifting cylinder (1).

5. The wide range of pressure thermocompression bonding system according to claim 1, characterized in that: The quartz heating tube (500) is a long strip structure, and a plurality of the quartz heating tubes (500) are arranged in parallel.

6. The wide range pressure thermocompression bonding system according to claim 1, characterized in that: An upper cold plate (100) is provided above the upper heating plate (300), and a lower cold plate (200) is provided below the lower heating plate (400). Both the upper cold plate (100) and the lower cold plate (200) are provided with cooling water pipes (119).

7. The wide range pressure thermocompression bonding system according to claim 6, characterized in that: The upper cold plate (100) is connected to the pressure output end (11).

8. The wide range of pressure thermocompression bonding system according to claim 1, characterized in that: The vacuum pumping system comprises a butterfly valve (160), a dry pump (80) and a molecular pump (140) which are connected in sequence.

9. The wide range pressure thermocompression bonding system according to claim 1, characterized in that: The vacuum breaking system comprises a diaphragm valve (50), a pressure gauge (60) and a pressure reducing valve (70) which are connected in sequence, and the pressure reducing valve (70) is connected to a nitrogen source.

10. A method for hot-press bonding over a wide range of pressures, characterized in that: A wide range of pressure thermocompression bonding system according to any one of claims 1 to 9 is used, comprising the following steps: The bonding chamber (120) is opened, the wafer mold is placed between the upper heating plate (300) and the lower heating plate (400), and the bonding chamber (120) is closed; the dry pump (80), molecular pump (140) and butterfly valve (160) of the vacuum system cooperate to control the vacuum degree of the bonding chamber (120) to reach the process vacuum degree; the pressurizing system controls the hydraulic cylinder (2) to extend, driving the upper heating plate (300) to descend, and controls the hydraulic cylinder (2) to output the process pressure through the electrical proportional valve to complete the pressurization; the upper heating plate (300) is pressed. The heating plate (300) and the lower heating plate (400) heat the wafer mold to the process temperature, and after keeping the temperature, the wafer pair (116) is thermally pressed and bonded; the upper heating plate (300) and the lower heating plate (400) components are heated and closed, and after the temperature drops to room temperature, the lifting cylinder (1) retracts, driving the upper heating plate (300) to rise, and the vacuum breaking system breaks the vacuum of the bonding chamber (120) to atmospheric pressure, and the bonding chamber (120) is opened, and the wafer mold is taken out, completing the entire bonding process.

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