A thermal compression bonding system and bonding method for a wide pressure range

Abstract

The present application belongs to the technical field of wafer bonding, and particularly relates to a large-range pressure thermal pressure bonding system and a bonding method. The large-range pressure thermal pressure bonding system comprises a bonding device, the bonding device is respectively connected with a pressurizing system, a vacuum pumping system and a vacuum breaking system, the bonding device comprises an upper heating disc and a lower heating disc below, quartz heating tubes are embedded in the upper heating disc and the lower heating disc, the pressurizing system comprises an electrical proportional valve, an input end of the electrical proportional valve is connected with a gas source, the electrical proportional valve is provided as a plurality of, an output end of each electrical proportional valve is correspondingly connected with a fluid pressure conversion device with different gas-liquid pressure conversion ratios, the fluid pressure conversion device is connected with a pressure output mechanism, and the output force range of the pressure output mechanism is 0-150KN. Through multi-system collaborative innovation, the present application realizes high precision, high efficiency and high reliability of wafer bonding process.

Description

Technical Field

[0001] This invention belongs to the field of wafer bonding technology, and particularly relates to a hot-press bonding system and bonding method with a large range of pressure. Background Technology

[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 wafer bonding, the performance of the heating pad is paramount, especially in terms of heating uniformity, temperature control accuracy, heating rate, and energy consumption. However, currently commonly used heating pad heat sources are typically disc-shaped heating wires, which have the following limitations:

[0003] Poor heating uniformity: The heating wires of the disc are usually arranged in a spiral or meandering pattern, which makes it difficult to achieve a completely uniform temperature distribution. Especially when heating a large area, the temperature of the edge area is usually lower than that of the center area, resulting in uneven heating of the wafer.

[0004] Slow heating rate: The heating rate of the disc heating wire is slow and the efficiency is low, making it difficult to meet the demand for rapid heating.

[0005] Difficulty in zoned heating: The disc heating wire makes it difficult to achieve zoned heating, and it is impossible to precisely control the heating according to the needs of different areas.

[0006] High energy consumption: Traditional heating wires require a high energy input to reach the required temperature, and the energy utilization rate is low.

[0007] Furthermore, in industrial production, especially in processes such as hot pressing, stamping, and forming, traditional pressure output devices typically operate only within a limited pressure range, making it difficult to meet diverse needs ranging from low to high pressure. For example, some equipment may require pre-pressing at low pressure and final forming or stamping at high pressure. Existing equipment often operates only within a single pressure range, failing to achieve full-range pressure output. Moreover, these devices also lack sufficient control precision and response speed, making it difficult to meet the high precision and rapid response requirements of modern industrial production.

[0008] Therefore, there is an urgent need for a device capable of outputting pressure over a wide range. This device should not only provide precise control across different pressure ranges but also possess efficient energy conversion, rapid response, and a compact structural design. Simultaneously, a heating plate structure capable of addressing uneven heating issues is also needed to improve the quality and efficiency of wafer bonding. Summary of the Invention

[0009] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a hot-press bonding system and bonding method with a large range of pressure.

[0010] To achieve the above objectives, the technical solution adopted is:

[0011] One objective of this invention is to provide a thermocompression bonding system with a large pressure range, comprising a bonding device connected to a pressurization system, a vacuum system, and a vacuum breaking system. The bonding device includes a bonding chamber containing an upper heating plate and a lower heating plate, each containing multiple quartz heating tubes. The pressurization system includes an electro-proportional valve, the input of which is connected to a gas source. Multiple electro-proportional valves are configured, and the output of each valve is connected to a fluid pressure conversion device with a different gas-liquid pressure conversion ratio. Each fluid pressure conversion device is connected to a pressure output mechanism with an output force range of 0-150 kN.

[0012] Preferably, there are three electro-proportional valves, and the outputs of the three electro-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.

[0013] The advantages of adopting the above-mentioned preferred technical solution are as follows: By setting three electro-proportional valves and connecting them to fluid pressure conversion devices with different gas-liquid pressure conversion ratios, the system can select the appropriate conversion device according to different pressure requirements, further improving the system's flexibility and control accuracy. Simultaneously, by rationally allocating conversion devices for different pressure ranges, the overall performance of the system is optimized, enabling efficient operation across various pressure ranges. A 1:1 conversion ratio means that air pressure is directly converted to hydraulic pressure, suitable for low pressure ranges (e.g., 0-14KN), providing rapid response and stable output. A 1:3 gas-liquid pressure conversion ratio is suitable for medium pressure ranges (e.g., 14-40KN), providing moderate output force. A 1:12 gas-liquid pressure conversion ratio can convert lower air pressure to higher hydraulic pressure, suitable for applications requiring high output force, such as the 40-150KN pressure range.

[0014] Preferably, the pressure output mechanism includes a hydraulic cylinder, one end of which is a piston rod, and the piston rod end is the pressure output end.

[0015] Preferably, the other end of the hydraulic cylinder is connected to a lifting cylinder.

[0016] The beneficial effects of adopting the above-mentioned preferred technical solution are as follows: The hydraulic cylinder, as a pressure output mechanism, can convert hydraulic energy into mechanical energy to achieve 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, thus improving the system's practicality and ease of operation. The hydraulic cylinder piston rod extends under the pressure of hydraulic oil, but there is no corresponding hydraulic oil circuit to retract the piston rod; therefore, an auxiliary cylinder is added to assist in the retraction of the hydraulic cylinder's piston rod.

[0017] Preferably, the fluid pressure conversion device is a wind-oil booster or a gas-liquid converter.

[0018] The advantages of adopting the above-mentioned preferred technical solutions are as follows: the fluid pressure conversion device uses either a blower-oil booster or a gas-liquid converter. These two devices can be selected according to different application scenarios and pressure requirements, providing diversified solutions. The blower-oil booster can achieve a higher pressure boost and is suitable for occasions requiring high pressure output; the gas-liquid converter is suitable for medium and low pressure ranges, and has the characteristics of simple structure and fast response, further enriching the system's functions and application scope.

[0019] Preferably, the fluid pressure conversion devices with gas-liquid pressure conversion ratios of 1:1, 1:3, and 1:12 are respectively a gas-liquid converter, a first air-oil booster, and a second air-oil booster, which are respectively connected to a first electro-proportional valve, a second electro-proportional valve, and a third electro-proportional valve. That is, the first electro-proportional valve is connected to the gas-liquid converter, the second electro-proportional valve is connected to the first air-oil booster, and the third electro-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 connected together to an oil three-way valve, which is also connected to a third pipeline. The third pipeline is connected to the pressure output mechanism.

[0020] The beneficial effect of adopting the above-mentioned preferred technical solution is that the structure of the three-way valve allows for switching between different air-oil boosters as needed to achieve output at different pressure ranges.

[0021] More preferably, the output end of the gas-liquid converter is connected to an oil manifold, which is connected to a first pipeline and a second pipeline respectively. The gas-liquid converter enters the oil through the first pipeline or the second pipeline and connects to the third pipeline via an oil three-way valve.

[0022] Preferably, the oil manifold is connected to the first pipeline via the output end of the first air-fuel booster, and the oil manifold is connected to the second pipeline via the output end of the second air-fuel booster.

[0023] The beneficial effect of adopting the above-mentioned preferred technical solution is that the hydraulic oil output from the gas-liquid converter only flows through the oil manifold to the output of the blower-oil booster, flows into the oil three-way valve through the first or second pipeline, and enters the pressure output mechanism through the third pipeline. The amplification effect of the blower-oil booster is not used. The amplification effect of the blower-oil booster requires the air supply of the electric proportional valve to achieve the amplification effect. Therefore, in the path output from the gas-liquid converter, the blower-oil booster only plays the role of providing the pipeline.

[0024] Preferably, the quartz heating tube has a long strip structure, and multiple quartz heating tubes are arranged in parallel.

[0025] The beneficial effects of adopting the above technical solution are as follows: Quartz heating tubes heat through 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 arranged in parallel can further provide a uniform heat distribution, ensuring uniform temperature within the heating plate. Quartz heating tubes have high thermal conductivity, enabling rapid heating and improving heating efficiency.

[0026] Preferably, the quartz heating tubes in the upper heating plate and the lower heating plate are arranged vertically in correspondence.

[0027] The beneficial effects of adopting the above-mentioned preferred technical solution are that the corresponding quartz heating tubes at the top and bottom can ensure the symmetrical heat distribution of the upper and lower heating plates, further improving the uniformity of heating.

[0028] More preferably, the quartz heating tube extends through both ends of the upper or lower heating plate.

[0029] The beneficial effect of adopting the above-mentioned preferred technical solution is that the through-hole quartz heating tube can more effectively transfer heat to all parts of the heating plate, thereby improving heat conduction efficiency.

[0030] Preferably, both the upper heating plate and the lower heating plate are equipped with four quartz heating tubes.

[0031] Preferably, a wafer pair is provided between the upper heating plate and the lower heating plate.

[0032] 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, with the graphite pads and the wafer pair located between the upper mold and the lower mold.

[0033] The advantages of adopting the above-mentioned preferred technical solution are as follows: the graphite pad can protect the wafer from direct contact with the mold and reduce damage; the mold can provide uniform pressure to ensure that the wafer maintains good contact and pressure distribution during the bonding process and achieves alignment of the two wafers.

[0034] Preferably, the mold pair has grooves inside that are adapted to the structure of the graphite pad and the wafer pair.

[0035] The advantages of adopting the above-mentioned preferred technical solution are that the groove is used to position the graphite pad and the wafer pair, reducing displacement during the heating process.

[0036] Preferably, an upper cooling plate is connected above the upper heating plate, and a lower cooling plate is connected below the lower heating plate. Cooling water pipes are provided in both the upper and lower cooling plates, and cooling water inlets and outlets are provided in both the upper and lower cooling plates. That is, the upper cooling plate has an upper cooling water inlet and an upper cooling water outlet, and the lower cooling plate has a lower cooling water inlet and a lower cooling water outlet.

[0037] More preferably, the cooling water pipe is embedded in the upper and lower cooling plates along a wavy path.

[0038] The advantages of adopting the above-mentioned preferred technical solution are: the cold plate can be quickly cooled by circulating water, improving cooling efficiency; the cold plate can effectively control the temperature of the heating plate and prevent overheating.

[0039] Preferably, hooks are provided between the upper heating plate and the upper cold plate, and between the lower heating plate and the lower cold plate.

[0040] The advantages of adopting the above-mentioned preferred technical solution are: the hook can ensure a stable connection between the cold plate and the heating plate, prevent displacement during operation, facilitate the installation and disassembly of the cold plate and the heating plate, and improve maintenance efficiency.

[0041] Preferably, one end of the hook is connected to the upper heating plate, and the other end is connected to the upper cold plate by a screw, with a compression spring fitted over the screw.

[0042] Preferably, one end of the hook is connected to the lower heating plate, and the other end is connected to the lower cooling plate by a screw, with a compression spring mounted on the screw.

[0043] The beneficial effect of adopting the above-mentioned preferred technical solution is that the heating plate undergoes 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, thus protecting the screw.

[0044] Preferably, the upper mold and the lower mold are connected by a locating pin.

[0045] Preferably, the bottom end of the lower mold is provided with a positioning groove, and the lower heating plate is provided with a positioning protrusion adapted to the structure of the positioning groove, for positioning the lower mold.

[0046] Preferably, the upper cooling plate is connected to the pressure output terminal.

[0047] Preferably, the bonding chamber is connected to a vacuum pumping system and a vacuum breaking system.

[0048] The advantages of adopting the above-mentioned preferred technical solution are as follows: the bonding chamber provides a carrier for wafer bonding, a closed-loop environmental control system is constructed, the vacuum system can evacuate the bonding chamber, and the vacuum breaking system can controllably restore the gas pressure with nitrogen to avoid damage to the wafer microstructure by sudden changes in gas pressure.

[0049] Preferably, the vacuum system includes a butterfly valve, a dry pump, and a molecular pump connected in sequence.

[0050] More preferably, the bonding chamber is connected to a butterfly valve via a pipeline, and the end of the butterfly valve away from the bonding chamber is connected to a dry pump via two branches. One branch consists of a slide gate valve, a molecular pump, a pre-vacuum gauge, and a pre-angle valve connected in sequence, and the other branch is equipped with a pipeline angle valve. The pipeline between the bonding chamber and the butterfly valve is connected to a vacuum gauge angle valve and a vacuum gauge in sequence via pipelines.

[0051] The advantages of adopting the above-mentioned preferred technical solution are as follows: The two-stage pumping scheme of dry pump + molecular pump balances pumping speed and ultimate vacuum. 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-pump the backing pipeline of the molecular pump. The vacuum gauge angle valve is kept open by default to monitor the chamber vacuum level in real time. When a low chamber pressure is detected, the vacuum gauge angle valve is closed to prevent contamination or overload damage to the vacuum gauge. The opening of the molecular pump requires a certain level of vacuum on both sides, which is provided by both the vacuum gauge and the backing vacuum gauge. The vacuum on both sides of the molecular pump is provided by the dry pump, hence the two pipelines. The vacuum level provided by the molecular pump is higher than that provided by the dry pump.

[0052] Preferably, the vacuum breaking system includes a diaphragm valve, a pressure gauge, and a pressure reducing valve connected in sequence via pipelines, wherein the pressure reducing valve is connected to a nitrogen source.

[0053] The advantages of adopting the above-mentioned preferred technical solution are as follows: through the coordinated control of the pressure reducing valve and the diaphragm valve, the vacuum breaking rate can be adjusted, and the pressure gauge is specifically a digital display pressure gauge, which provides real-time feedback to ensure process controllability.

[0054] Preferably, the bonding chamber is connected to a process vacuum gauge.

[0055] The advantages of adopting the above-mentioned preferred technical solution are as follows: 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 can be used during the process to monitor the vacuum level of the bonding chamber.

[0056] The second objective of this invention is to provide a hot-press bonding method with a large pressure range, employing the aforementioned hot-press bonding system, comprising the following steps: opening the bonding chamber, placing the wafer mold between the heating plate and the lower heating plate, and closing the bonding chamber; the dry pump, molecular pump, and butterfly valve of the vacuum system working together to control the vacuum level of the bonding chamber to reach the process vacuum level; the pressurization system controlling the extension of the hydraulic cylinder to drive the upper heating plate to descend, and controlling the output of the hydraulic cylinder to complete the pressurization through an electro-proportional valve; the upper and lower heating plates heating the wafer mold to the process temperature, and after holding at that temperature, completing the hot-press bonding of the wafer pair; the upper and lower heating plate assemblies heating and closing, and after the temperature drops to room temperature, the lifting cylinder retracting, driving the upper heating plate to rise, the vacuum breaking system breaking the vacuum in the bonding chamber to atmospheric pressure, opening the bonding chamber, removing the wafer mold, and completing the entire bonding process.

[0057] Preferably, the output force range of 0-150KN is divided into three range segments: 0-14KN, 14-40KN, and 40-150KN, which are controlled by a first electro-proportional valve, a third electro-proportional valve, and a second electro-proportional valve, respectively.

[0058] The advantages of adopting the above-mentioned preferred technical solution are as follows: through segmented control, each electro-proportional valve can accurately control the corresponding pressure range, thereby improving the control accuracy of the system; different pressure ranges are achieved by different combinations of electro-proportional valves and boosters, ensuring that the system can operate efficiently under different pressures; segmented control can avoid overloading of a single booster at full range, thereby improving the stability and service life of the system.

[0059] Preferably, the pressure range at the output ends of the first electro-proportional valve, the third electro-proportional valve, and the second electro-proportional valve is 0-0.8 MPa.

[0060] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0061] This invention's thermocompression bonding system achieves high precision, high efficiency, and high reliability in wafer bonding processes through multi-system collaborative innovation. The system employs a two-stage pumping design using both dry and molecular pumps, enabling rapid establishment of a high vacuum environment. Combined with dynamically protected vacuum gauges and butterfly valves, the pumping process remains stable and reliable. A three-stage gas-liquid conversion pressure system, combined with quartz heating tube infrared radiation heating technology, shortens the overall process time and allows for higher pressure outputs, up to 150 kN, essentially meeting the pressure output requirements for all thermocompression bonding applications. The system is fully controllable from 0 to 150 kN, requiring only gas pressure control within the 0-0.8 MPa range to stably output the corresponding thrust. The segmented control method further improves the system's control accuracy and operational efficiency, making it suitable for various industrial applications. The heating plate structure of this invention, with multiple quartz heating tubes arranged in parallel, provides uniform heat distribution, ensuring uniform temperature within the heating plate. The quartz heating tubes possess highly efficient thermal conductivity, enabling rapid heating and improving heating efficiency. Attached Figure Description

[0062] Figure 1 This is a structural diagram of a hot-press bonding system with a large pressure range according to the present invention;

[0063] Figure 2 This is a schematic diagram of the pressure output system with a large range according to the present invention;

[0064] Figure 3 This is a front view of the pressure output system with a large range according to the present invention;

[0065] Figure 4 This is a structural gas and liquid circuit diagram of the pressure output system with a large range according to the present invention;

[0066] Figure 5 This is a schematic diagram of a heating plate structure that uses a quartz heating tube as a heat source.

[0067] Figure 6 for Figure 5 Enlarged view of point A in the middle;

[0068] Figure 7 This is a front view of a heating plate structure that uses a quartz heating tube as a heat source.

[0069] Figure 8 This is a cross-sectional view of a heating plate structure that uses a quartz heating tube as a heat source.

[0070] Figure 9 This is a cross-sectional view of the mold pair and the wafer pair;

[0071] The attached diagram is labeled as follows: 1. Lifting cylinder; 2. Hydraulic cylinder; 3. Oil three-way valve; 4. Oil manifold; 5. Second air-oil booster; 6. First electro-proportional valve; 7. Second electro-proportional valve; 8. Third electro-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 cooling plate; 110. Lower cooling plate cooling water inlet; 111. Lower cooling plate cooling water outlet; 112. 113. Upper mold; 114. Lower mold; 115. Positioning pin; 116. Graphite pad; 117. Wafer pair; 118. Screw; 119. Positioning groove; 110. Cooling water pipe; 120. Bonding chamber; 130. Pre-vacuum gauge; 140. Molecular pump; 150. Slide valve; 160. Butterfly valve; 170. Vacuum gauge; 180. Pre-vacuum 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 Implementation

[0072] The present invention will be described below with reference to examples. These examples are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0073] refer to Figures 1-9 A hot-press bonding system with a large pressure range includes a bonding device, which is connected to a pressurization system, a vacuum system, and a vacuum breaking system. The bonding device includes a bonding chamber 120, which contains an upper heating plate 300 and a lower heating plate 400. Multiple quartz heating tubes 500 are embedded in both the upper and lower heating plates 300 and 400. The pressurization system includes an electro-proportional valve, the input of which is connected to a gas source. Multiple electro-proportional valves are configured, and the output of each valve is 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, the output force of which has a range of 0-150 kN.

[0074] In a preferred embodiment, three electro-proportional valves are provided, and the output terminals of the three electro-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.

[0075] In a preferred embodiment, the pressure output mechanism includes a hydraulic cylinder 2, one end of which is a piston rod, and the piston rod end is the pressure output end 11.

[0076] In a preferred embodiment, the other end of the hydraulic cylinder 2 is connected to the lifting cylinder 1.

[0077] In a preferred embodiment, the fluid pressure conversion device is a wind-oil booster or a gas-liquid converter 10.

[0078] In a preferred embodiment, the fluid pressure conversion devices with gas-liquid pressure conversion ratios of 1:1, 1:3, and 1:12 are a gas-liquid converter 10, a first air-oil booster 9, and a second air-oil booster 5, respectively, which are connected to a first electro-proportional valve 6, a second electro-proportional valve 7, and a third electro-proportional valve 8. That is, the first electro-proportional valve 6 is connected to the gas-liquid converter 10, the second electro-proportional valve 7 is connected to the first air-oil booster 9, and the third electro-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 connected to a three-way oil valve 3, which is also connected to a third pipeline 14. The third pipeline 14 is connected to the pressure output mechanism.

[0079] In a preferred embodiment, the output end of the gas-liquid converter 10 is connected to an oil manifold 4, which is connected to a first pipeline 12 and a second pipeline 13. The gas-liquid converter 10 enters the oil three-way valve 3 via the oil manifold 4 through the first pipeline 12 or the second pipeline 13 and is connected to the third pipeline 14.

[0080] In a preferred embodiment, the oil manifold 4 is connected to the first pipeline 12 via the output end of the first air-fuel booster 9, and the oil manifold 4 is connected to the second pipeline 13 via the output end of the second air-fuel booster 5.

[0081] In a preferred embodiment, the quartz heating tube 500 has a long strip structure, and multiple quartz heating tubes 500 are arranged in parallel.

[0082] In a preferred embodiment, the quartz heating tubes 500 in the upper heating plate 300 and the lower heating plate 400 are arranged vertically in correspondence.

[0083] In this embodiment, the quartz heating tube 500 passes through both ends of the upper heating plate 300 or the lower heating plate 400.

[0084] In this embodiment, both the upper heating plate 300 and the lower heating plate 400 are provided with four quartz heating tubes 500.

[0085] In this embodiment, a wafer pair 116 is provided between the upper heating plate 300 and the lower heating plate 400.

[0086] In 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. Graphite pads 115 are provided above and below the wafer pair 116, and the graphite pads 115 and the wafer pair 116 are located between the upper mold 112 and the lower mold 113.

[0087] In a preferred embodiment, the mold pair is provided with grooves that are adapted to the structure of the graphite pad 115 and the wafer pair 116.

[0088] In a preferred embodiment, an upper cooling plate 100 is connected above the upper heating plate 300, and a lower cooling plate 200 is connected below the lower heating plate 400. Both the upper cooling plate 100 and the lower cooling plate 200 are provided with cooling water pipes 119. The upper cooling plate 100 is provided with an upper cooling water inlet 800 and an upper cooling water outlet 900, and the lower cooling plate 200 is provided with a lower cooling water inlet 110 and a lower cooling water outlet 111.

[0089] In a preferred embodiment, the cooling water pipe 119 is embedded in the upper cooling plate 100 and the lower cooling plate 200 along a wavy path.

[0090] In 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.

[0091] 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 by a screw 117. A compression spring 700 is provided on the outer sleeve of the screw 117.

[0092] 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 by a screw 117. A compression spring 700 is fitted over the screw 117.

[0093] In this embodiment, the upper mold 112 and the lower mold 113 are connected by a locating pin 114.

[0094] In an optional embodiment, the bottom end of the lower mold 113 is provided with a positioning groove 118, and the lower heating plate 400 is provided with a positioning protrusion adapted to the structure of the positioning groove 118, for positioning the lower mold 113.

[0095] In this embodiment, the upper cooling plate 100 is connected to the pressure output terminal 11.

[0096] In this embodiment, the bonding chamber 120 is connected to a vacuum pumping system and a vacuum breaking system.

[0097] In an optional embodiment, the vacuum system includes a butterfly valve 160, a dry pump 80, and a molecular pump 140 connected in sequence.

[0098] In an optional embodiment, the bonding chamber 120 is connected to the butterfly valve 160 via a pipeline. The end of the butterfly valve 160 away from the bonding chamber 120 is connected to the dry pump 80 via two branches. One branch consists of a slide gate valve 150, a molecular pump 140, a pre-vacuum gauge 130, and a pre-angle valve 180 connected in sequence. The other branch is equipped with a pipeline angle valve 90. The pipeline between the bonding chamber 120 and the butterfly valve 160 is connected to a vacuum gauge angle valve 190 and a vacuum gauge 170 in sequence via pipelines.

[0099] 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 via pipelines, wherein the pressure reducing valve 70 is connected to a nitrogen source.

[0100] In an optional embodiment, the bonding chamber 120 is connected to a process vacuum gauge 25.

[0101] This invention also provides a hot-press bonding method for the aforementioned large-range pressure range, comprising the following steps: opening the bonding chamber 120, placing the wafer mold between the upper heating plate 300 and the lower heating plate 400, and closing the bonding chamber 120; 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 pressurization system controls the hydraulic cylinder 2 to extend, driving the upper heating plate 300 to descend, and controlling the hydraulic cylinder 2 to output process pressure through an electro-proportional valve to complete the pressurization; the upper heating plate 300 and the lower heating plate 400 heat the wafer mold to reach the process temperature, and after holding the temperature, complete the hot-press bonding of the wafer to 116; the upper heating plate 300 and the lower heating plate 400 assembly heats up and closes, and after the temperature drops to room temperature, the lifting cylinder 1 retracts, driving the upper heating plate 300 to rise, the vacuum breaking system breaks the vacuum of the bonding chamber 120 to atmospheric pressure, the bonding chamber 120 opens, the wafer mold is taken out, and the entire bonding process is completed.

[0102] In this embodiment, the output force range of 0-150KN is divided into three range segments: 0-14KN, 14-40KN, and 40-150KN. These three range segments are controlled by the first electro-proportional valve 6, the third electro-proportional valve 8, and the second electro-proportional valve 7, respectively.

[0103] In this embodiment, the pressure range of the output terminals of the first electro-proportional valve 6, the third electro-proportional valve 8, and the second electro-proportional valve 7 is 0-0.8 MPa.

[0104] Working process of the hot-press bonding system of the present invention

[0105] 1. System Initialization

[0106] Chamber preparation: Open bonding chamber 120, place the aligned wafer mold between upper heating plate 300 and lower heating plate 400, and close the chamber to form a sealed environment.

[0107] Vacuum establishment:

[0108] Vacuum gauge valve 190 is kept open by default. When the dry pump 80 is started, the pipeline valve 90 and the fore-stage valve 180 are opened simultaneously. The coarse pumping process is started with the butterfly valve 160 fully open.

[0109] Dry pump 80 simultaneously evacuates the bonding chamber 120 and the pre-stage pipeline of molecular pump 140. When the vacuum level of the pre-stage pipeline is ≤0.1mbar, molecular pump 140 is started.

[0110] After the molecular pump 140 reaches its rated speed, the slide gate valve 150 is opened to perform high-vacuum pumping, and the system's ultimate vacuum can reach 10. -6 mbar level;

[0111] The chamber pressure is monitored in real time by process vacuum gauge 25 and vacuum gauge 170, and the opening of butterfly valve 160 is dynamically adjusted to maintain the set vacuum level.

[0112] 2. Bonding process execution

[0113] Stress loading:

[0114] The pressurization system selects the pressure range (0-14KN / 14-40KN / 40-150KN) according to process requirements, and the corresponding electro-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.

[0115] The piston rod of hydraulic cylinder 2 extends, pushing components such as the upper heating plate 300 and the upper cooling plate 100 downward to apply pressure. The pressure value is controlled by the closed loop formula F=P×S.

[0116] Heat bonding:

[0117] The quartz heating tubes 500 inside the upper heating plate 300 and the lower heating plate 400 heat up synchronously and quickly reach the set temperature;

[0118] The wafers are bonded under constant temperature and pressure conditions, and the holding time is set according to the material properties.

[0119] 3. Process termination and wafer removal

[0120] Cooling phase:

[0121] Turn off the heating system and allow the chamber temperature to cool naturally to room temperature (or cool down faster by using cooling water pipe 119).

[0122] When the lifting cylinder 1 moves, it drives the upper heating plate 300, upper cooling plate 100 and other components to reset.

[0123] Vacuum breaking and film removal:

[0124] After bonding is completed, close the slide gate valve 150 and butterfly valve 160, open the diaphragm valve 50, adjust the nitrogen input pressure with the pressure reducing valve 70, and monitor the vacuum breaking rate with the pressure gauge 60.

[0125] After the chamber is restored to normal pressure, the chamber is opened and the bonded wafer mold is removed.

[0126] Specifically, the working process during the pressure loading stage is as follows: When the pressure output mechanism needs to output 10KN of pressure, the first electro-proportional valve 6 controls the output of 0.5MPa gas pressure to the gas-liquid converter 10. The gas-liquid converter 10 converts the gas pressure into hydraulic oil of corresponding pressure at a 1:1 ratio for output. The hydraulic oil 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 opening of the oil circuit of 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). The hydraulic oil is then forced 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 the pressure, S is the piston area of ​​the hydraulic cylinder 2, and F is the thrust, the piston rod end of the hydraulic cylinder 2 of the pressure output mechanism can output a thrust of approximately 10KN. The specific calculation process is as follows:

[0127] ;

[0128] When the pressure output mechanism needs to output 100KN, the second electro-proportional valve 7 controls the output of approximately 0.42MPa gas pressure to the first air-oil booster 9. The first air-oil booster 9 converts the 0.42MPa gas pressure into 5.04MPa hydraulic oil pressure for output at a ratio of 1:12. The oil is controlled by the three-way valve 3 to open the oil circuit of the first pipeline 12 corresponding to the first air-oil booster 9. The hydraulic oil is then forced into the hydraulic cylinder 2 through the third pipeline 14. According to F=P*S, P is taken as 5.04MPa and S is taken as 0.0201m. 2 The piston rod end of the hydraulic cylinder 2 of the pressure output mechanism can output a thrust of about 100KN;

[0129] Similarly, when the pressure output mechanism needs to output 30KN of pressure, the third electro-proportional valve 8 controls the output of approximately 0.5MPa of gas pressure to the second hydraulic booster 5. The second hydraulic booster 5 converts the 0.5MPa gas pressure into 1.5MPa hydraulic oil pressure for output at a ratio of 1:3. The oil is controlled by the three-way valve 3 to open the oil circuit of the second pipeline 13 corresponding to the second hydraulic booster 5. The hydraulic oil is then forced into the hydraulic cylinder 2 through the third pipeline 14. According to F=P*S, P is taken as 1.5MPa and S is taken as 0.0201m. 2 The piston rod end of the hydraulic cylinder 2 of the pressure output mechanism can output a thrust of about 30KN.

[0130] During operation, the specific steps involved in heat bonding are as follows: In the chamber preparation stage, a graphite pad 115 is placed into the groove of the lower mold 113, the wafer pair 116 to be bonded is placed into the groove of the lower mold 113, and then another graphite pad 115 is placed on top. The upper mold 112 is aligned with the lower mold 113 and pressed in, with the positioning pin 114 in place. The assembled wafer is aligned with the mold and pressed into the protrusion in the middle of the lower heating plate 400. An electric cylinder is connected above the upper cooling plate 100. During the bonding process, the electric cylinder drives the upper cooling plate 100, upper heating plate 300, quartz heating tube 500, 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, thus completing the pressurization of the wafer pair 116. The quartz heating tube 500 is electrically heated, and the upper heating plate 300 and lower heating plate 400 are rapidly heated by infrared radiation. After the temperature rises to the process temperature, it is held at that temperature for half an hour. Cooling water is introduced into the upper cooling plate cooling water inlet 800 and the lower cooling plate cooling water inlet 110 to rapidly cool the upper heating plate 300 and lower heating plate 400 to the set temperature, such as 20°C. Then, the electric cylinder drives the upper cooling plate 100, upper heating plate 300, quartz heating tube 500, and hook 600 to rise to the initial position. The mold pair is then removed from the lower heating plate 400, the upper mold 112 and graphite pad 115 are opened, and the bonded wafer pair 116 is taken out, thus completing the hot-press bonding of the wafer pair 116. The entire bonding process is simple and quick. The quartz heating tube 500 heats up rapidly and reaches a higher temperature; the cooling plate cools down quickly, shortening the overall process time.

[0131] 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 within the protection scope of the present invention.

Claims

1. A hot-press bonding system with a large pressure range, characterized in that, The system includes a bonding device, which is connected to a pressurization system, a vacuum system, and a vacuum breaking system. The bonding device includes a bonding chamber (120), which has an upper heating plate (300) and a lower heating plate (400). Both the upper heating plate (300) and the lower heating plate (400) are embedded with quartz heating tubes (500). The pressurization system includes an electro-proportional valve, the input of which is connected to a gas source. Multiple electro-proportional valves are configured, and the output of each electro-proportional valve is 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.

2. The hot-press bonding system with a large pressure range according to claim 1, characterized in that, The electro-proportional valve is configured as three, and the output terminals of the three electro-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 hot-press bonding system with a large pressure range according to claim 1, characterized in that, The pressure output mechanism includes a hydraulic cylinder (2), one end of which is a piston rod, and the piston rod end is the pressure output end (11).

4. The hot-press bonding system with a large pressure range according to claim 3, characterized in that, The other end of the hydraulic cylinder (2) is connected to a lifting cylinder (1).

5. The hot-press bonding system with a large pressure range according to claim 1, characterized in that, The quartz heating tube (500) has a long strip structure, and multiple quartz heating tubes (500) are arranged in parallel.

6. The hot-press bonding system with a large pressure range according to claim 3, characterized in that, An upper cooling plate (100) is provided above the upper heating plate (300), and a lower cooling plate (200) is provided below the lower heating plate (400). Both the upper cooling plate (100) and the lower cooling plate (200) are provided with cooling water pipes (119).

7. The hot-press bonding system with a large pressure range according to claim 6, characterized in that, The upper cooling plate (100) is connected to the pressure output terminal (11).

8. The hot-press bonding system with a large pressure range according to claim 1, characterized in that, The vacuum system includes a butterfly valve (160), a dry pump (80), and a molecular pump (140) connected in sequence.

9. The hot-press bonding system with a large pressure range according to claim 1, characterized in that, The vacuum breaking system includes a diaphragm valve (50), a pressure gauge (60), and a pressure reducing valve (70) connected in sequence, with the pressure reducing valve (70) connected to a nitrogen source.

10. A hot-press bonding method with a large pressure range, characterized in that, The hot-press bonding system with a large pressure range as described in any one of claims 1-9 includes 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 work together to control the vacuum level of the bonding chamber (120) to reach the process vacuum level; the pressurization system controls the hydraulic cylinder (2) to extend, driving the upper heating plate (300) to descend, and the hydraulic cylinder (2) outputs process pressure through the electro-proportional valve to complete the pressurization; the upper heating plate (300) is closed; the lower heating plate (400) is closed; the upper heating plate (300) is closed; the upper heating plate (400) is closed; the lower heating plate (4 ... The heating plate (300) and the lower heating plate (400) heat the wafer mold to the process temperature. After holding the temperature, the hot pressing bonding of the wafer pair (116) is completed. The heating plate (300) and the lower heating plate (400) assembly are turned off. After the temperature drops to room temperature, the lifting cylinder (1) retracts and drives the upper heating plate (300) to rise. The vacuum breaking system breaks the vacuum in the bonding chamber (120) to atmospheric pressure. The bonding chamber (120) is opened, the wafer mold is taken out, and the entire bonding process is completed.

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