Heating and cooling system for wafer bonding equipment

Abstract

The invention relates to a heating and cooling system for wafer bonding equipment, which comprises a basic unit, a heating unit and a cooling unit, and is characterized in that the basic unit comprises an upper disc, a heating bin and a lower disc, and the heating bin is used for accommodating a wafer to be bonded and providing a vacuum environment for the wafer; the upper disc and the lower disc can be driven to be close to each other so as to apply set pressure to the wafer; an upper heater and a lower heater of the heating unit are used for heating the wafer in the axial direction, and an edge heater is used for carrying out heat compensation in the radial direction; an upper cooler and a lower cooler of the cooling unit are used for indirectly cooling the wafer; the wafer bonding device effectively improves heating uniformity and cooling efficiency in the wafer bonding process, can provide an accurate and effective vacuum environment for wafer bonding, and is simple in structure and easier to maintain and repair.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor processing, and in particular to a heating and cooling system for wafer bonding equipment. Background Art

[0002] Wafers are the fundamental material in semiconductor manufacturing and the key carrier for the production of integrated circuits and other microelectronic devices. They are typically made from high-purity single-crystal silicon and, after undergoing a series of precision machining processes, are ultimately cut into chips. Wafer bonding is a micro-nanofabrication technology that permanently joins two or more wafers together through physical or chemical means. It is widely used in semiconductor packaging, MEMS (micro-electromechanical systems), power devices, and other fields.

[0003] In conventional wafer bonding equipment, the heating system often utilizes a single-sided heat conduction path and insufficiently compensates for heat loss in the edge region, resulting in a radial temperature gradient on the wafer surface. The edge region is significantly cooler than the center, directly causing non-uniform diffusion at the bonding interface. The cooling system relies on a single medium circulation path, and heat exchange efficiency is limited by the contact area and fluid dynamics. This results in thermal stress accumulation within the wafer during the cooling phase that exceeds the material tolerance threshold. The equipment's mechanical structure utilizes multi-level transmission modules and split temperature control components, resulting in an extended heat conduction path and unbalanced axial pressure distribution.

[0004] In addition, many wafer bonding processes need to be carried out in a high vacuum environment. In order to create a vacuum environment, the existing technology often chooses to use a cover or box to wrap the entire heating system and then perform a vacuum treatment. This not only takes a long time and is costly to establish a vacuum, but also the vacuum is easily destroyed during the dynamic bonding process, which affects the bonding effect.

[0005] If these issues are not addressed, temperature gradients at the wafer bonding interface will cause the thickness of the metal interdiffusion layer to exceed process specifications, directly impacting the consistency of device electrical performance. Microcracks caused by accumulated thermal stress can expand into fatal structural defects during subsequent ion implantation. The complex equipment structure not only prolongs maintenance cycles but also increases cumulative positioning accuracy errors due to repeated disassembly and assembly, severely compromising process stability.

[0006] In view of the above problems, the existing technology is in urgent need of improvement. Summary of the Invention

[0007] In view of this, the present invention provides a heating and cooling system for wafer bonding equipment, which effectively improves the heating uniformity and cooling efficiency during the wafer bonding process, has a simple structure, and is easier to maintain and repair.

[0008] The present invention specifically discloses a heating and cooling system for wafer bonding equipment, comprising: The base unit includes an upper plate, a heating chamber, and a lower plate arranged in sequence along a vertical direction. The heating chamber includes a heat-conducting tray and a heat-conducting cover. The top surface of the heat-conducting tray is recessed downward to form a heating chamber for placing wafers to be bonded. The heat-conducting cover is detachably mounted on the bottom surface of the upper plate. The heat-conducting tray and the upper plate can be driven close to each other, and the heat-conducting cover moves with the movement to abut against the top surface of the wafer to be bonded and close the heating chamber. The upper plate and the lower plate can be driven close to each other so that the lower plate abuts against the bottom surface of the heat-conducting tray, and the upper plate and the lower plate are close to each other to apply a set pressure to the wafer. The basic unit also includes a vacuum machine, and the heating chamber is also provided with a vacuum tube, one end of the vacuum tube is connected to the heating chamber, and the other end is connected to the vacuum machine. The vacuum machine evacuates the heating chamber through the vacuum tube so that the heating chamber is in a vacuum state when closed; The heating unit includes an upper heater, a lower heater, and an auxiliary heating system. The upper heater is embedded in the upper plate and heats the heat-conducting cover plate through the upper plate to indirectly heat the wafer. The lower heater is embedded in the lower plate and heats the heat-conducting tray through the lower plate to indirectly heat the wafer. The auxiliary heating system includes an edge heater, which is installed on the heat-conducting tray and surrounds the heating cavity in the circumferential direction. The cooling unit includes an upper cooler and a lower cooler. The upper cooler is installed on the upper plate. The upper cooler cools the heat-conducting cover plate through the upper plate to indirectly cool the wafer; the lower cooler is installed on the lower plate. The lower cooler cools the heat-conducting tray through the lower plate to indirectly cool the wafer.

[0009] Furthermore, the basic unit also includes an upper mounting plate and a lower mounting plate, and the cooling unit also includes an upper water-cooling screen and a lower water-cooling screen. The upper mounting plate, the upper water-cooling screen and the upper plate are connected in sequence from top to bottom; the lower mounting plate, the lower water-cooling screen and the lower plate are connected in sequence from bottom to top.

[0010] Furthermore, it also includes a cold screen host, and the auxiliary heating system also includes an auxiliary heat source and a switching valve. The cold screen host, the upper water cooling screen, the auxiliary heat source and the edge heater are connected in series in sequence to form a closed circulation loop. One end of the switching valve is connected between the cold screen host and the upper water cooling screen, and the other end is connected between the auxiliary heat source and the edge heater; the lower water cooling screen and the upper cold screen host are arranged in parallel.

[0011] Furthermore, it also includes a first control valve and a second control valve. The first control valve is arranged between the upper water cooling screen and the auxiliary heat source. One end of the second control valve is connected between the upper cooling screen and the first control valve, and the other end is connected between the edge heater and the cooling screen host.

[0012] Furthermore, the upper heater and the lower heater are respectively arranged in the upper plate and the lower plate in a coiled and embedded manner. After coiling, the heating area of ​​the lower heater is equal to the heating area of ​​the upper heater.

[0013] Furthermore, the upper cooler includes an upper water-cooling plate, an upper water-cooling pipe, and an upper water-cooling machine. The top surface of the upper plate is recessed downward in the vertical direction to form an upper mounting cavity. The upper water-cooling plate is embedded in the upper mounting cavity, and the top surface of the upper water-cooling plate is flush with the top surface of the upper plate. The upper water-cooling pipe is embedded in the upper water-cooling plate and fits the upper plate. The upper water-cooling machine is connected to the upper water-cooling pipe. The upper water-cooling machine is used to pump the cooling medium into and out of the upper water-cooling pipe to form a cooling cycle. The lower cooler includes a lower water-cooling plate, a lower water-cooling pipe and a lower water-cooling machine. The bottom surface of the lower plate is concave upward in the vertical direction to form a lower installation cavity. The lower water-cooling plate is embedded and installed in the lower installation cavity, and the bottom surface of the lower water-cooling plate is flush with the bottom surface of the lower plate. The lower water-cooling pipe is embedded in the lower water-cooling plate and fits with the lower plate. The lower water-cooling machine is connected to the lower water-cooling pipe. The lower water-cooling machine is used to pump the cooling medium into and out of the lower water-cooling pipe to form a cooling cycle.

[0014] Furthermore, the cooling unit further comprises a heat insulation screen, wherein the middle portion of the heat insulation screen in the axial direction is a hollow structure, and the heat insulation screen is provided with a plurality of ventilation holes penetrating in the axial direction; There are multiple heat insulation screens, including an upper heat insulation screen arranged between the upper water-cooling screen and the upper plate and a lower heat insulation screen arranged between the lower water-cooling screen and the lower plate; the two axial end faces of the upper heat insulation screen are respectively fitted with the upper water-cooling screen and the upper water-cooling plate, and the two axial end faces of the lower heat insulation screen are respectively fitted with the lower water-cooling screen and the lower water-cooling plate.

[0015] Furthermore, it also includes a fixed pressure plate for fixing the heat-conducting tray, and a plurality of fixed pressure plates are provided along the circumference of the heat-conducting tray; The fixed pressure plate includes a plate body, a base and an elastic fastener. The plate body is installed on the base, and the base is installed on the upper mounting plate through the elastic fastener. The heat-conducting tray is provided with a slot, and the end of the plate body is bent in the direction of the heat-conducting tray and clamped in the slot; the elastic fastener has an elastic pre-tightening force in the vertical direction, and the elastic pre-tightening force acts on the base so that the plate body has a tendency to move upward.

[0016] Furthermore, the basic unit further includes a push plate mounted on the top surface of the upper mounting plate in a manner that the push plate can be driven to move in a vertical direction.

[0017] Furthermore, it also includes a control unit, which includes a controller and a temperature sensor. There are multiple temperature sensors, and the multiple temperature sensors are respectively arranged on the upper plate and the lower plate. The control unit is used to receive temperature information collected by the multiple temperature sensors and adjust the corresponding setting parameters of the heating unit and the cooling unit according to the temperature information.

[0018] Beneficial effects of the present invention: The present invention discloses a heating and cooling system for wafer bonding equipment. By combining a heating chamber with a vacuum machine, a vacuum environment is established in the bonding area, providing a precise and effective vacuum environment for the bonding process at a lower cost. By simultaneously arranging heating devices above, below, and circumferentially of the wafer, independent and controllable heating channels are established in both the circumferential and circumferential directions of the wafer. The cooling unit and the heating unit are integrated into the same heat transfer medium, enabling temperature control to achieve bidirectional heat flow transfer through the same contact surface, achieving a dynamic balance between the temperature field and the pressure field during the wafer bonding process within a single device. The multi-directional heat conduction path eliminates edge thermal gradients, while the vertically stacked mechanical structure reduces equipment complexity while ensuring heat exchange efficiency. The present invention, through the synergistic effect of the base unit, the heating unit, and the cooling unit, adopts a combination of axial heating and radial heat supplementation, direct cooling and indirect cooling, and establishes a local vacuum by applying a set pressure. This solves the problems of uneven heating, low cooling efficiency, difficulty in establishing a vacuum environment, and complex structure in the prior art, and has the advantages of improving bonding quality, reducing thermal stress defects, and simplifying maintenance processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is the front view of the present invention; Figure 2 A top view of the present invention; Figure 3 for Figure 2 Cross-sectional view at AA in the middle; Figure 4 for Figure 3 A partial enlarged view of point B in the middle; Figure 5 It is an exploded schematic diagram of the assembly structure of the push plate, upper mounting plate, upper water cooling screen, upper heat insulation screen, upper cooler, upper heater, upper plate and heating chamber of the present invention; Figure 6 It is a schematic diagram of the assembly structure of the lower plate, lower heater, lower cooler, lower heat shield, lower water cooling shield and lower mounting plate of the present invention; Figure 7 It is a front view of the heat shield of the present invention; Figure 8 for Figure 7 Cross-sectional view at the middle BB; Figure 9 It is a structural schematic diagram of the fixed pressing plate of the present invention; Figure 10 It is a front view of the fixed pressure plate of the present invention; Figure 11 for Figure 10 Cross-sectional view at CC; Figure 12 It is a structural schematic diagram of the heat-conducting tray of the present invention; Figure 13Schematic diagram of the system structure of the auxiliary heating system of the present invention; Figure numerals: upper plate 1, lower plate 2, heat-conducting tray 3, upper water-cooling screen 4, lower water-cooling screen 5, upper mounting plate 6, lower mounting plate 7, heat insulation screen 8, support column 801, ventilation hole 802, fixed pressure plate 9, plate body 901, base 902, fixing bolt 903, spring 904, push plate 10, bellows 11, upper heater 12, upper water-cooling pipe 13, upper water-cooling plate 14, lower heater 15, lower water-cooling plate 16, lower water-cooling pipe 17, heat-conducting cover plate 18, edge heater 19, vacuum tube 20, auxiliary heat source 21, switching valve 22, first control valve 23, second control valve 24, cold screen host 25. DETAILED DESCRIPTION

[0020] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0021] It should be noted that, in the description of this specification, the terms "upper", "lower", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0022] like Figure 1-10As shown, this embodiment specifically discloses a heating and cooling system for wafer bonding equipment, the basic unit includes an upper plate 1, a heating chamber and a lower plate 2 arranged in sequence along the vertical direction, the heating chamber includes a heat-conducting tray 3 and a heat-conducting cover 18, the top surface of the heat-conducting tray 3 is recessed downward to form a heating chamber for placing the wafers to be bonded, the heat-conducting cover 18 is detachably mounted on the bottom surface of the upper plate 1, the heat-conducting tray 3 and the upper plate 1 can be driven close to each other, the heat-conducting cover 18 moves with the movement to press against the top surface of the wafer to be bonded and close the heating chamber; the upper plate 1 and the lower plate 2 can be driven close to each other so that the lower plate 2 presses against the bottom surface of the heat-conducting tray 3, and the upper plate 1 and the lower plate 2 are close to each other to apply a set pressure to the wafer; the basic unit also includes a vacuum machine, and the heating chamber is further provided with a vacuum tube 20, one end of the vacuum tube 20 is connected to the heating chamber, and the other end is connected to the vacuum machine, and the vacuum machine is connected to the heating chamber through the vacuum tube 20. The heating chamber is evacuated to make the heating chamber in a vacuum state when closed; the heating unit includes an upper heater 12, a lower heater 15 and an auxiliary heating system, the upper heater 12 is embedded in the upper plate 1, and the upper heater 12 heats the heat-conducting cover plate 18 through the upper plate 1 to indirectly heat the wafer; the lower heater 15 is embedded in the lower plate 2, and the lower heater 15 heats the heat-conducting tray 3 through the lower plate 2 to indirectly heat the wafer; the auxiliary heating system includes an edge heater 19, and the edge heater 19 is installed on the heat-conducting tray 3 and surrounds the heating chamber in the circumferential direction; the cooling unit includes an upper cooler and a lower cooler, the upper cooler is installed on the upper plate 1, and the upper cooler cools the heat-conducting cover plate through the upper plate 1 to indirectly cool the wafer; the lower cooler is installed on the lower plate 2, and the lower cooler cools the heat-conducting tray 3 through the lower plate 2 to indirectly cool the wafer. Compared to establishing a vacuum environment based on the entire device, a heating chamber is provided in this embodiment, and a vacuum environment is specifically established based on the heating chamber, providing a precise and effective vacuum environment for the bonding process, which is less expensive and more efficient. In this embodiment, the heat-conducting cover plate 18 can be detachably installed on the bottom surface of the upper plate 1 by methods such as bonding and snapping. A sealing structure such as a sealing ring is provided at the peripheral position of the heat-conducting cover plate 18 to ensure that the heating chamber is in a sealed state after the heat-conducting cover plate 18 is covered. At the same time, a channel is opened at the bottom of the heat-conducting tray 3 to install a vacuum tube 20. One end of the vacuum tube 20 is connected to the bottom surface of the heating chamber, and the other end is connected to a vacuum machine such as a vacuum pump to achieve the establishment of a vacuum environment. A valve can be provided on the vacuum tube 20 to destroy the vacuum environment.

[0023] Conventional equipment transfers energy only through a single-sided heat source, which cannot compensate for the thermal radiation and conduction losses around the wafer. The difference in thermal resistance between the upper and lower plates and the wafer contact surface further exacerbates the uneven temperature distribution. In addition, the conventional cooling module is physically isolated from the heating system, and heat exchange must be conducted through a multi-layer structure. The difference in heat capacity leads to inconsistent cooling rates. Compared with the prior art, the present application not only establishes independent and controllable heating channels on the upper and lower surfaces of the wafer, but also adds edge heaters to heat the wafer in the radial direction for thermal compensation, effectively avoiding the radial temperature difference caused by the loss of heat at the edge during the bonding process. The cooling unit and the heating unit are integrated into the same heat transfer medium, so that temperature control can achieve bidirectional heat flow transfer through the same contact surface. In addition, the application of pressure in this embodiment is achieved by driving the upper plate 1 and the lower plate 2 closer to each other. In the prior art, the separate design of the pressure applying mechanism and the temperature control module increases the mechanical complexity, and the multi-stage transmission device increases the risk of thermal expansion interference. However, the axially integrated layout of the present application achieves pressure loading and thermal interface contact simultaneously through vertical linear motion, which is simpler in structure and easier to repair and maintain. In this embodiment, the synchronized pressurization of the upper and lower plates (2) and the dual-path heating and cooling system coordinate to achieve a dynamic balance between temperature and pressure during wafer bonding within a single device. The upper plate (1) heats and cools the top surface of the wafer via a thermally conductive cover plate, while the lower plate (2) indirectly regulates the bottom temperature of the wafer via a thermally conductive tray (3). Edge heaters (19) apply heat radially to prevent heat loss at the wafer's periphery. Multi-directional heat conduction paths eliminate edge thermal gradients, while the vertically stacked mechanical structure ensures efficient heat exchange while reducing device complexity.

[0024] In this embodiment, the base unit further includes an upper mounting plate 6 and a lower mounting plate 7, and the cooling unit further includes an upper water-cooling screen 4 and a lower water-cooling screen 5. The upper mounting plate 6, the upper water-cooling screen 4, and the upper plate 1 are sequentially connected from top to bottom; the lower mounting plate 7, the lower water-cooling screen 5, and the lower plate 2 are sequentially connected from bottom to top. The upper mounting plate 6 and the lower mounting plate 7 serve as the installation foundation. In this embodiment, the upper water-cooling screen 4 and the upper plate 1 are sequentially connected and then mounted on the upper mounting plate 6. Bolts can be used to achieve multi-layer stacking. The lower mounting plate 7, the lower water-cooling screen 5, and the lower plate 2 are sequentially connected from bottom to top, which can be achieved through stepped assembly to form mechanical limits or through bolts to achieve multi-layer stacking.

[0025] In this embodiment, a cold screen host 25 is also included, and the auxiliary heating system also includes an auxiliary heat source 21 and a switching valve 22. The cold screen host 25, the upper water-cooled screen 4, the auxiliary heat source 21 and the edge heater 19 are connected in series in sequence to form a closed circulation loop. One end of the switching valve 22 is connected between the cold screen host 25 and the upper water-cooled screen 4, and the other end is connected between the auxiliary heat source 21 and the edge heater 19; the lower water-cooled screen 5 and the upper cold screen host 25 are arranged in parallel. In this embodiment, a first control valve 23 and a second control valve 24 are also included. The first control valve 23 is arranged between the upper water-cooled screen 4 and the auxiliary heat source 21. One end of the second control valve 24 is connected between the upper cold screen and the first control valve 23, and the other end is connected between the edge heater 19 and the cold screen host 25. Figure 13 As shown, the upper water-cooling screen 4 and the lower water-cooling screen 5 in this embodiment are circulating water-cooling devices with the same structure, and only the setting positions are different. The upper water-cooling screen 4 and the lower water-cooling screen 5 share a cold screen host 25. The upper and lower water-cooling screens have two functions. One is to absorb heat to isolate heat radiation to avoid damage to other components caused by temperature increase during the bonding process. The other is to cooperate with the corresponding water cooler to further reduce the temperature of the corresponding upper and lower plates to achieve a rapid temperature drop. The dual cooling structure can effectively expand the temperature adjustment range, and this hierarchical connection structure can optimize the heat conduction path and improve the cooling efficiency. In this embodiment, the edge heater 19 is a spiral tube that shares a cold screen main unit 25 with the upper water cooling screen 4 to achieve circulation. The water outlet of the upper water cooling screen 4 (i.e., the cooling medium whose temperature has increased after the cooling and heat exchange) continues to enter the edge heater 19, and uses the remaining heat to supplement the heat in the radial direction of the wafer. After the heating is completed, the water outlet of the edge heater 19 returns to the cold screen main unit 25, cools, and continues the next round of circulation. In order to ensure the heating effect of the edge heater 19, an auxiliary heat source 21 is also provided in front of the edge heater 19. If the temperature of the medium flowing out of the upper water cooling screen 4 differs too much from the temperature of the medium required by the edge heater 19, the auxiliary heat source 21 is activated to heat the medium to meet the operating requirements. The auxiliary heat source 21 can be a heating device such as an electric heating wire. In this embodiment, a switching valve 22, a first control valve 23, and a second control valve 24 are also provided so that the edge heater 19 can not only be used as a heater for heating, but also as a heat exchanger for cooling. The specific operating conditions are as follows: When used for heating, the switching valve 22 and the second control valve 24 are closed, the first control valve 23 is opened, and the medium flows out from the cold screen host 25. Part of the medium flows into the lower water cooling screen 5 and then flows back to the cold screen host 25. The rest flows through the upper water cooling screen 4 and the edge heater 19 in sequence and then flows back to the cold screen host 25. The auxiliary heat source 21 is operated or not according to actual needs. When used for cooling, the switching valve 22 and the second control valve 24 are opened, the first control valve 23 is closed, and the medium flows out of the cold screen host 25 in three directions. One is to flow through the lower water cooling screen 5 and then return to the cold screen host 25. The second is to directly enter the edge heater 19 for heat exchange and then return to the cold screen host 25. The third is to flow through the upper water cooling screen 4 and then return to the cold screen host 25.

[0026] The edge heater 19 in this embodiment effectively utilizes the redundant heat of the upper water cooling screen 4, and through the switching and coordination of multiple valves, effectively realizes the heating and cooling of the wafer in the radial direction, avoiding the generation of temperature gradients caused by edge temperature loss during wafer bonding, and combined with the coolers of the upper and lower plates, further improves the cooling speed and cooling efficiency, thereby improving overall work efficiency and optimizing product quality.

[0027] In this embodiment, the upper heater 12 and the lower heater 15 are respectively arranged in a coiled and embedded manner within the upper and lower plates 1 and 2, respectively. After coiling, the heating area of ​​the lower heater 15 is equal to the heating area of ​​the upper heater 12. In this embodiment, dense serpentine slots are provided in both the upper and lower plates 1 and 2, and the upper heater 12 and the lower heater 15 are respectively embedded in the slots of the upper and lower plates 1 and 2. The upper and lower heaters 12 and 15 can be made of resistance wire material, and the heating power is controlled by adjusting the current. In this embodiment, the upper heater 12 and the lower heater 15 are respectively embedded in the upper and lower plates 1 and 2 to achieve heating. The heating area in this embodiment refers to the projected area of ​​the area directly heated by the corresponding heater, not the area of ​​heat irradiation. More specifically, it refers to the area covered by the coiled heater. Designing the heating areas of the two heaters to be consistent ensures that the upper and lower heaters heat the same amount, heating more evenly, and avoiding radial temperature differences, especially the occurrence of excessively high temperatures on one side.

[0028] In this embodiment, the upper cooler includes an upper water-cooling plate 14, an upper water-cooling pipe 13 and an upper water-cooling machine. The top surface of the upper plate 1 is concave downward in the vertical direction to form an upper mounting cavity. The upper water-cooling plate 14 is embedded in the upper mounting cavity, and the top surface of the upper water-cooling plate 14 is flush with the top surface of the upper plate 1. The upper water-cooling pipe 13 is embedded in the upper water-cooling plate 14 and fits the upper plate 1. The upper water-cooling machine is connected to the upper water-cooling pipe 13. The upper water-cooling machine is used to pump the cooling medium into and out of the upper water-cooling pipe 13 to form a cooling medium. circulation; the lower cooler includes a lower water-cooling plate 16, a lower water-cooling pipe 17 and a lower water-cooling machine. The bottom surface of the lower plate 2 is recessed upward in the vertical direction to form a lower mounting cavity. The lower water-cooling plate 16 is embedded in the lower mounting cavity, and the bottom surface of the lower water-cooling plate 16 is flush with the bottom surface of the lower plate 2. The lower water-cooling pipe 17 is embedded in the lower water-cooling plate 16 and fits with the lower plate 2. The lower water-cooling machine is connected to the lower water-cooling pipe 17. The lower water-cooling machine is used to pump the cooling medium into and out of the lower water-cooling pipe 17 to form a cooling cycle. In this embodiment, the upper cooler and the lower cooler are both water-cooled circulation devices, and the recessed depth of the upper mounting cavity and the lower mounting cavity is designed to be equal to the thickness of the corresponding water-cooled plate, so that the surface of the water-cooled plate after embedding is flush with the corresponding plate body; the water-cooling pipe is embedded in the water-cooled plate in a serpentine or spiral shape, and the upper cooler and the lower cooler are respectively provided with water coolers for control, thereby realizing separate control of the cooling of the upper and lower plates 2; at the same time, the cooling area of ​​the upper water-cooling pipe 13 is not less than the heating area of ​​the upper heater 12, and the cooling area of ​​the lower water-cooling pipe 17 is not less than the heating area of ​​the lower heater 15. This arrangement effectively solves the temperature control lag problem caused by insufficient coverage of the cooling pipe, and by establishing a positive proportional relationship between the cooling area and the heating area, it ensures that the heat absorption path is completely corresponding to the heat generation area, and eliminates the local heat residual phenomenon caused by the lack of heat conduction path during the indirect cooling process, so that the wafer bonding interface can achieve uniform heat dissipation during the cooling stage, thereby reducing the interface stress defects caused by the temperature gradient.

[0029] In this embodiment, the cooling unit also includes a heat insulation screen 8, the axial middle part of the heat insulation screen 8 is a hollow structure, and the heat insulation screen 8 is provided with a plurality of ventilation holes 802 that pass through in the axial direction; there are multiple heat insulation screens 8, and the multiple heat insulation screens 8 include an upper heat insulation screen arranged between the upper water-cooling screen 4 and the upper plate 1 and a lower heat insulation screen arranged between the lower water-cooling screen 5 and the lower plate 2; the two axial end faces of the upper heat insulation screen are respectively corresponding to the upper water-cooling screen 4 and the upper water-cooling plate 14, and the two axial end faces of the lower heat insulation screen are respectively corresponding to the lower water-cooling screen 5 and the lower water-cooling plate 16. In this embodiment, the upper heat insulation screen and the lower heat insulation screen are only different in setting positions, but are consistent in structure and function. The heat insulation screen 8 in this embodiment is made of ceramic material, and is a structure with a hollow middle portion formed by connecting the upper and lower parts through a plurality of scattered support columns 801, and a plurality of axially through heat dissipation holes are also opened simultaneously. The setting of the heat insulation screen 8 can further cool down and insulate. The upper heat insulation screen is set between the upper water-cooled screen 4 and the upper plate 1. Firstly, it reduces the heat transfer in the direction of the upper mounting plate 6 (that is, the direction of other components). Secondly, the hollow structure of the heat insulation screen 8 can increase the heat exchange area and form convection heat exchange during the cooling process. Combined with the water cooling device (upper water cooler and upper water-cooled screen 4), the overall cooling efficiency is further enhanced. Moreover, the air flow channel formed by the hollow structure and the ventilation holes 802 promotes the uniform diffusion of heat through air convection, thereby avoiding local heat accumulation.

[0030] This embodiment also includes a fixed pressure plate 9 for fixing the heat transfer tray 3. Multiple fixed pressure plates 9 are arranged along the circumference of the heat transfer tray 3. The fixed pressure plates 9 include a plate body 901, a base 902, and an elastic fastener. The plate body 901 is mounted on the base 902, and the base 902 is mounted to the upper mounting plate 6 via the elastic fastener. The heat transfer tray 3 is provided with a slot. The end of the plate body 901 is bent toward the heat transfer tray 3 and snapped into the slot. The elastic fastener has an elastic preload in the vertical direction. The elastic preload acts on the base 902 to cause the plate body 901 to have an upward movement tendency. In this embodiment, the bending structure at the end of the plate body 901 can be set to an L-shape or a hook shape, with a bending angle between 60 and 120 degrees. The slot depth can be 1.2 to 2 times the thickness of the plate body 901. Multiple fixed pressure plates 9 are distributed along the circumference at intervals of 30 to 60 degrees, and the number is 6 to 12. During the installation process, the bent portion at the end of the plate body 901 is embedded in the slot of the heat-conducting tray 3 to form a lateral limit. The upward preload force provided by the elastic fastener is transmitted to the plate body 901 through the base 902, so that the contact surface between the heat-conducting tray 3 and the upper plate 1 maintains a constant pressure. When the heat-conducting tray 3 expands due to heat, the elastic fastener deforms in the vertical direction to compensate for the dimensional changes caused by thermal expansion. At the same time, the bent structure of the plate body 901 limits the lateral displacement. During the cooling process, the elastic preload force continues to act to avoid contact surface gaps caused by material shrinkage. The connection method between the base 902 and the upper mounting plate 6 allows the plate body 901 to float slightly in the vertical direction, so that the preload force of multiple fixed pressure plates 9 is evenly distributed. The gap between the side wall of the slot and the bent portion is controlled at 0.05-0.2mm, which not only ensures assembly accuracy but also avoids thermal expansion jamming. The elastic fastener in this embodiment is a fixing bolt 903 with a spring 904. The fixing bolt 903 passes through the base 902 and is connected to the upper mounting plate 6. The spring 904 is pressed against the base 902 to provide an elastic preload. The setting of the fixed pressure plate 9 can effectively maintain the pressure uniformity of the contact surface between the heat-conducting tray 3 and the upper and lower plates 2. The circumferentially distributed fixed pressure plates 9 form a dynamically balanced clamping system through the synergistic effect of mechanical limiting and elastic preload. Among them, the cooperation between the hook structure and the card slot eliminates lateral displacement, and the axial compensation ability of the spring 904 allows the heat-conducting tray 3 to produce controllable micro-deformations, thereby avoiding contact surface separation caused by thermal expansion. This structure continuously maintains a stable heat conduction interface under high temperature conditions, improves the heating uniformity of the wafer, reduces the bonding layer thickness deviation to within 5%, and prevents bonding dislocation defects caused by mechanical vibration.

[0031] In this embodiment, the base unit further includes a push plate 10, which is mounted on the top surface of the upper mounting plate 6 in a manner that allows it to be driven and moved in the vertical direction. The push plate 10 can be pushed by an electric push rod, a pneumatic push rod, or other mechanical transmission structure. In this embodiment, a plurality of bellows 11 are mounted on the push plate 10, and gas is passed through the bellows 11 to achieve the push and pull motion of the push plate 10 in a pneumatic manner.

[0032] In this embodiment, a control unit is also included. The control unit includes a controller and a temperature sensor. There are multiple temperature sensors, and the multiple temperature sensors are respectively correspondingly arranged on the upper plate 1 and the lower plate 2. The control unit is used to receive the temperature information collected by the multiple temperature sensors, and adjust the corresponding setting parameters of the heating unit and the cooling unit according to the temperature information. In this embodiment, the setting parameters include but are not limited to the heating power of the upper heater 12 and the lower heater 15, the flow rate of the cooling medium of the upper cooler and the lower cooler, and other direct or indirect operating parameters related to the heating effect and the cooling effect. Specifically, in this embodiment, the temperature sensor adopts a thermocouple with a temperature measurement range of 0-600℃ and an accuracy of ±0.5℃. The specific distribution position of the temperature sensor can be specifically arranged according to the size of the wafer to be bonded. The controller can be a host equipped with a setting program that can send and receive signals. The controller adopts a PID control algorithm with a sampling period of 100ms. Based on real-time temperature data fed back by the temperature sensors, the controller dynamically adjusts operating parameters such as the power output of the upper and lower heaters 15 and the cooling medium flow rate of the upper and lower coolers. For example, if the temperature in a certain area of ​​the upper plate 1 is detected to be below the set value, the controller increases the power of the upper heater 12 corresponding to that area and simultaneously reduces the cooling medium flow rate of the upper water cooler in that area. Conversely, if the temperature is detected to be above the set value, the controller reduces the heating power and increases the cooling medium flow rate. The temperature regulation principle of the lower plate 2 is similar. The controller can also predict thermal field changes based on temperature distribution trends and adjust parameters in advance. This achieves precise temperature control over the entire wafer area, ensuring temperature uniformity during the bonding process. This setup enables precise dynamic control of the wafer thermal field. Multi-point real-time temperature monitoring and a closed-loop adjustment mechanism effectively eliminate temperature gradients between the upper and lower plates 2, ensuring uniform heating and cooling of the wafer. Rapid response to thermal field changes avoids local overheating or insufficient cooling. This improves bonding quality and consistency, reduces defects caused by thermal stress accumulation, and enhances process stability and yield.

[0033] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A heating and cooling system for wafer bonding equipment, characterized in that: include: The base unit includes an upper plate, a heating chamber, and a lower plate arranged in sequence along a vertical direction. The heating chamber includes a heat-conducting tray and a heat-conducting cover plate. The top surface of the heat-conducting tray is recessed downward to form a heating chamber for placing wafers to be bonded. The heat-conducting cover plate is detachably mounted on the bottom surface of the upper plate. The heat-conducting tray and the upper plate can be driven close to each other, and the heat-conducting cover plate moves with the drive to abut against the top surface of the wafer to be bonded and close the heating chamber. The upper plate and the lower plate can be driven close to each other so that the lower plate abuts against the bottom surface of the heat-conducting tray, and the upper plate and the lower plate are close to each other to apply a set pressure to the wafer. The basic unit further includes a vacuum machine, and the heating chamber is further provided with a vacuum tube, one end of the vacuum tube is connected to the heating chamber, and the other end is connected to the vacuum machine, and the vacuum machine evacuates the heating chamber through the vacuum tube so that the heating chamber is in a vacuum state when closed; The heating unit includes an upper heater, a lower heater, and an auxiliary heating system. The upper heater is embedded in the upper plate and heats the heat-conducting cover plate through the upper plate to indirectly heat the wafers. The lower heater is embedded in the lower plate and heats the heat-conducting tray through the lower plate to indirectly heat the wafers. The auxiliary heating system includes an edge heater, which is mounted on the heat-conducting tray and circumferentially surrounds the heating chamber. The cooling unit includes an upper cooler and a lower cooler. The upper cooler is installed on the upper plate, and the upper cooler cools the heat-conducting cover plate through the upper plate to indirectly cool the wafer; the lower cooler is installed on the lower plate, and the lower cooler cools the heat-conducting tray through the lower plate to indirectly cool the wafer.

2. A heating and cooling system for wafer bonding equipment according to claim 1, characterized in that: The basic unit also includes an upper mounting plate and a lower mounting plate, and the cooling unit also includes an upper water-cooling screen and a lower water-cooling screen. The upper mounting plate, the upper water-cooling screen and the upper plate are connected in sequence from top to bottom; the lower mounting plate, the lower water-cooling screen and the lower plate are connected in sequence from bottom to top.

3. The heating and cooling system for wafer bonding equipment according to claim 2, characterized in that: It also includes a cold screen host, and the auxiliary heating system also includes an auxiliary heat source and a switching valve. The cold screen host, upper water cooling screen, auxiliary heat source and edge heater are connected in series in sequence to form a closed circulation loop. One end of the switching valve is connected between the cold screen host and the upper water cooling screen, and the other end is connected between the auxiliary heat source and the edge heater; the lower water cooling screen is arranged in parallel with the upper cold screen host.

4. The heating and cooling system for wafer bonding equipment according to claim 3, characterized in that: It also includes a first control valve and a second control valve. The first control valve is arranged between the upper water cooling screen and the auxiliary heat source. One end of the second control valve is connected between the upper cooling screen and the first control valve, and the other end is connected between the edge heater and the cooling screen host.

5. The heating and cooling system for wafer bonding equipment according to claim 1, wherein: The upper heater and the lower heater are respectively arranged in the upper plate and the lower plate in a coiled and embedded manner. After coiling, the heating area of ​​the lower heater is equal to the heating area of ​​the upper heater.

6. The heating and cooling system for wafer bonding equipment according to claim 2, wherein: The upper cooler includes an upper water-cooling plate, an upper water-cooling pipe and an upper water-cooling machine. The top surface of the upper plate is recessed downward in the vertical direction to form an upper mounting cavity. The upper water-cooling plate is embedded in the upper mounting cavity, and the top surface of the upper water-cooling plate is flush with the top surface of the upper plate. The upper water-cooling pipe is embedded in the upper water-cooling plate and fits the upper plate. The upper water-cooling machine is connected to the upper water-cooling pipe. The upper water-cooling machine is used to pump the cooling medium into and out of the upper water-cooling pipe to form a cooling cycle. The lower cooler includes a lower water-cooling plate, a lower water-cooling pipe and a lower water-cooling machine. The bottom surface of the lower plate is recessed upward in the vertical direction to form a lower installation cavity. The lower water-cooling plate is embedded in the lower installation cavity, and the bottom surface of the lower water-cooling plate is flush with the bottom surface of the lower plate. The lower water-cooling pipe is embedded in the lower water-cooling plate and fits the lower plate. The lower water-cooling machine is connected to the lower water-cooling pipe. The lower water-cooling machine is used to pump the cooling medium into and out of the lower water-cooling pipe to form a cooling cycle.

7. The heating and cooling system for wafer bonding equipment according to claim 6, characterized in that: The cooling unit further comprises a heat insulation screen, wherein the middle portion of the heat insulation screen in the axial direction is a hollow structure, and the heat insulation screen is provided with a plurality of ventilation holes penetrating in the axial direction; There are multiple heat insulation screens, including an upper heat insulation screen arranged between the upper water-cooling screen and the upper plate and a lower heat insulation screen arranged between the lower water-cooling screen and the lower plate; the two axial end faces of the upper heat insulation screen are respectively correspondingly fitted with the upper water-cooling screen and the upper water-cooling plate, and the two axial end faces of the lower heat insulation screen are respectively correspondingly fitted with the lower water-cooling screen and the lower water-cooling plate.

8. The heating and cooling system for wafer bonding equipment according to claim 2, wherein: It also includes a fixed pressure plate for fixing the heat-conducting tray, wherein a plurality of the fixed pressure plates are arranged along the circumference of the heat-conducting tray; The fixed pressure plate includes a plate body, a base and an elastic fastener, the plate body is mounted on the base, and the base is mounted on the upper mounting plate via the elastic fastener, the thermal tray is provided with a slot, and the end of the plate body is bent toward the thermal tray and snapped into the slot; The elastic fastener has an elastic pre-tightening force upward in a vertical direction, and the elastic pre-tightening force acts on the base to make the plate have a tendency to move upward.

9. The heating and cooling system for wafer bonding equipment according to claim 4, characterized in that: The basic unit further includes a push plate mounted on the top surface of the upper mounting plate in a manner such that the push plate can be driven to move in a vertical direction.

10. The heating and cooling system for wafer bonding equipment according to claim 1, wherein: It also includes a control unit, which includes a controller and a temperature sensor. There are multiple temperature sensors, and the multiple temperature sensors are respectively arranged on the upper plate and the lower plate. The control unit is used to receive temperature information collected by the multiple temperature sensors and adjust the corresponding setting parameters of the heating unit and the cooling unit according to the temperature information.

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