Non-normal-temperature laminating method and system for substrate in liquid

Abstract

The invention relates to the technical field of display panels, in particular to a non-normal-temperature laminating method and system for a substrate in liquid. Comprising the following steps: S100, mounting and fixing an upper substrate and a lower substrate respectively; s200, adjusting and aligning the upper substrate and the lower substrate; s300, the upper substrate is gradually moved downwards to be close to the lower substrate; s400, circulating liquid is injected to adjust the upper substrate and the lower substrate to the set temperature; s500, pressing the upper substrate and the lower substrate and carrying out curing treatment; and S600, the upper substrate and the lower substrate which are attached are taken out. The method has the advantages of providing the non-normal-temperature environment, reducing interference, standardizing the technological process and improving the working precision, solves the problems of lack of the non-normal-temperature environment, interference, nonstandard process and low working precision in the existing substrate laminating work, and meets the requirements of laminating processing of the substrate.

Description

Technical Field

[0001] The present application relates to the technical field of display panels, and in particular to a method and system for very warm bonding of substrates in liquid. Background Art

[0002] The display panel is a key component of the display device. It forms an image through a large number of pixels to display information on the device. Display panels can be divided into self-luminous and non-self-luminous panels, and they usually have a multi-layer structure. During production and processing, it is necessary to manufacture the functional panels of each layer separately, and then assemble multiple substrates in a certain order to obtain the required display panel. In this process, specific processes need to be followed so that the two target substrates can be bonded.

[0003] The existing substrate bonding work is usually carried out at room temperature, but some new panels have very low temperature working conditions and need to maintain low or high temperatures during the bonding process. If the normal temperature process is used, it is easy to cause material failure. On the other hand, when maintaining a new very low temperature environment, the substrate bonding work is easily affected and additional measures are required to eliminate interference. The existing process is difficult to achieve. It is necessary to optimize the process flow to achieve standardized production, reduce the confusion caused by process upgrades, and use more reasonable processes for standardization to meet the requirements of new panels. Therefore, a very low temperature bonding method and system for substrates in liquid is needed to solve the above-mentioned deficiencies. Summary of the invention

[0004] In view of the defects of the prior art, the purpose of this application is to provide a method and system for non-normal temperature bonding of substrates in liquid, aiming to solve the technical problems existing in the existing substrate bonding process, such as lack of non-normal temperature environment, interference, non-standard process and low working precision.

[0005] To achieve the above object, the present application provides a method for very warm bonding of substrates in liquid, comprising the following steps:

[0006] S100: installing and fixing the upper base plate and the lower base plate respectively;

[0007] S200: adjusting and aligning the upper substrate and the lower substrate;

[0008] S300: gradually moving the upper substrate downward to make it close to the lower substrate;

[0009] S400: injecting circulating fluid to adjust the upper substrate and the lower substrate to a set temperature;

[0010] S500: pressing the upper substrate and the lower substrate and performing a curing process;

[0011] S600: taking out the upper substrate and the lower substrate that have been bonded.

[0012] In some embodiments, the steps of separately mounting and fixing the upper substrate and the lower substrate include:

[0013] S101, coating optical adhesive on the upper substrate and the lower substrate respectively;

[0014] S102, placing the lower substrate in the tank, and placing the upper substrate above the lower substrate;

[0015] S103, moving the upper substrate and the lower substrate to the vacuum suction cup respectively;

[0016] S104, start the vacuum pump connected to the vacuum suction cup to absorb and fix the upper substrate and the lower substrate.

[0017] In some embodiments, the lower substrate is placed in the trough body and the upper substrate is arranged above the lower substrate, which specifically includes: the upper substrate and the lower substrate are arranged in an inclined state, and the inclination angle is 10° to 45°.

[0018] In some embodiments, the step of adjusting and aligning the upper substrate and the lower substrate comprises:

[0019] S201: Start the visual camera to take pictures of the upper substrate and the lower substrate;

[0020] S202: Acquire multiple characteristic patterns on the photographed substrate;

[0021] S203: Analyze the characteristic pattern to obtain the relative error between the positions of the upper substrate and the lower substrate;

[0022] S204: Move or rotate the upper substrate and the lower substrate to return the relative error to zero.

[0023] In some embodiments, the characteristic patterns are QR codes, and the characteristic patterns are arranged in pairs.

[0024] In some embodiments, the step of gradually moving the upper substrate downward to make it close to the lower substrate includes:

[0025] S301: moving the upper substrate downward and detecting the distance between the upper substrate and the lower substrate;

[0026] S302: Determine whether the distance is less than the safety distance;

[0027] S303: When the distance is greater than the safety distance, the upper substrate continues to move downward;

[0028] S304: When the distance is less than or equal to the safety distance, the movement of the upper substrate is stopped.

[0029] In some embodiments, the safety distance is 5 to 15 mm.

[0030] In some embodiments, the upper substrate and the lower substrate are pressed and cured, the upper substrate is pushed under pressure to make it fit with the lower substrate, and then an ultraviolet lamp is used to irradiate the upper substrate and the lower substrate to cure the optical glue between the upper substrate and the lower substrate. The irradiation time of the ultraviolet lamp is 2 to 10 seconds.

[0031] In some embodiments, the method of removing the bonded upper substrate and lower substrate comprises:

[0032] S601: Discharge the circulating fluid in the tank;

[0033] S602: Turn off the vacuum pump to stop the vacuum suction cup from adsorbing;

[0034] S603: applying pre-pressure to the upper substrate and gradually withdrawing the vacuum chuck;

[0035] S604: taking out the upper substrate and the lower substrate that have been bonded.

[0036] A substrate very warm bonding system in liquid, applied to a substrate very warm bonding method in liquid, the system comprising:

[0037] A fixing module, used for installing and fixing the upper base plate and the lower base plate respectively;

[0038] An alignment module, used for adjusting and aligning the upper substrate and the lower substrate;

[0039] A moving module, used for gradually moving the upper substrate downward to make it close to the lower substrate;

[0040] A cooling module is used to inject circulating fluid to adjust the upper substrate and the lower substrate to a set temperature;

[0041] A curing module, used for pressing the upper substrate and the lower substrate and performing a curing process;

[0042] The exit module is used to take out the upper substrate and the lower substrate that have been bonded.

[0043] The beneficial effects of the technical solution provided by this application include:

[0044] The embodiments of the present application provide a method and system for non-normal temperature bonding of substrates in liquid, which has the advantages of providing a non-normal temperature environment, reducing interference, standardizing the process flow and improving working precision. It solves the problems existing in the existing substrate bonding work, such as lack of a non-normal temperature environment, interference, non-standardized process and low working precision, and meets the needs of substrate bonding processing.

[0045] The present application places the upper substrate and the lower substrate to be bonded in a tank body, and then injects circulating liquid to change the temperature. According to the low temperature or high temperature requirements of the process, the required ambient temperature can be adjusted, and the use of circulating liquid can continuously maintain the temperature stability, which is conducive to the bonding of new panels. In addition, the present application moves the substrates in steps during bonding, and when the bonding is completed and taken out, pre-pressure is applied to the upper substrate to prevent damage. These measures reduce the interference caused by the liquid environment and ensure the yield rate of substrate bonding.

[0046] On the other hand, the present application optimizes and improves the conventional substrate bonding process, forms a perfect non-warm bonding process, realizes standardization and process flow, and facilitates stable operation during large-scale production. The present application also uses visual positioning for deviation correction, adjusts and aligns the upper and lower substrates, and applies pressure to tighten them after moving them into place, further improving the bonding accuracy, reducing misalignment, and meeting the high-precision requirements of new display panels. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of the method flow of the present application;

[0048] Figure 2 is a flow chart of step S100 of the present application;

[0049] Figure 3 It is a flowchart of step S200 of the present application;

[0050] Figure 4 It is a flowchart of step S300 of the present application;

[0051] Figure 5 is a flowchart of step S600 of the present application;

[0052] Figure 6 It is a schematic diagram of the system structure of this application;

[0053] Figure 7 It is a schematic diagram of the tilted state in an embodiment of the present application.

[0054] In the figure:

[0055] 1. Fixing module, 2. Alignment module, 3. Moving module, 4. Cooling module, 5. Curing module, 6. Exit module, 7. Upper substrate, 8. Lower substrate, 9. Vision camera. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0057] The embodiment of the present application provides a method for very-low-temperature bonding of substrates in liquid, which utilizes a vacuum suction cup to adsorb the upper substrate and the lower substrate to be bonded, and then aligns the upper substrate and the lower substrate through visual positioning adjustment, and then pressurizes and bonds them, and processes the upper substrate and the lower substrate through photocuring, and finally takes out the bonded substrates, thereby solving the problems of existing substrate bonding work, such as lack of a very-low-temperature environment, interference, irregular process and low working precision.

[0058] like Figure 1 As shown, a method for bonding substrates in a liquid at very low temperature comprises the following steps:

[0059] S100: installing and fixing the upper base plate and the lower base plate respectively;

[0060] Further, such as Figure 2 As shown, the step S100 of separately installing and fixing the upper substrate and the lower substrate includes:

[0061] S101, coating optical adhesive on the upper substrate and the lower substrate respectively;

[0062] Specifically, the optical adhesive is a colorless and transparent special adhesive with a light transmittance of more than 90%. It can be cured at room temperature, medium temperature or ultraviolet irradiation, and has a small curing shrinkage. The optical adhesive includes but is not limited to optical resin, which is used to bond the upper substrate and the lower substrate. As a feasible implementation of the present application, the coated optical adhesive is sprayed on the upper substrate and the lower substrate using a nozzle, and the sprayed surfaces of the upper substrate and the lower substrate are oppositely arranged surfaces to be bonded, forming a film layer with bonding function. The advantage of this setting is to control the amount of optical adhesive used to avoid dripping.

[0063] S102, placing the lower substrate in the tank, and placing the upper substrate above the lower substrate;

[0064] Specifically, the lower substrate is placed in the trough body, and the upper substrate is arranged above the lower substrate. In this step, the upper substrate and the lower substrate are arranged in an inclined state, and the inclination angle is 10° to 45° so that they can fit normally. The advantage of this arrangement is that when the circulating liquid is subsequently injected, the circulating liquid enters the gap between the upper substrate and the lower substrate, and bubbles are easily generated due to uneven distribution. The present application arranges the upper substrate and the lower substrate at an angle so that the circulating liquid enters from the edge or a corner and gradually fills the gap between the upper substrate and the lower substrate, thereby reducing the problem of bubble generation.

[0065] S103, moving the upper substrate and the lower substrate to the vacuum suction cup respectively;

[0066] S104, start the vacuum pump connected to the vacuum suction cup to absorb and fix the upper substrate and the lower substrate.

[0067] The purpose of this step is to adsorb the upper substrate and the lower substrate to the bottom of the vacuum suction cup through the negative pressure generated by the vacuum pump. The advantage of this setting using adsorption fixation is that it reduces damage to the substrate and is easy to remove.

[0068] S200: adjusting and aligning the upper substrate and the lower substrate;

[0069] Further, such as Figure 3 As shown, the adjustment and alignment of the upper substrate and the lower substrate in step S200 includes:

[0070] S201: Start the visual camera to take pictures of the upper substrate and the lower substrate;

[0071] When the upper substrate and the lower substrate are both adsorbed and fixed, the visual camera is started to take pictures. As a feasible implementation of the present application, multiple visual cameras are provided, and the multiple visual cameras are spaced apart so as to take multi-angle pictures of the upper substrate and the lower substrate from different positions. The advantage of this setting is to improve the accuracy of positioning. Optionally, when the upper substrate and the lower substrate are set to be transparent, the visual camera can obtain images of the upper substrate and the lower substrate at the same time to simplify the shooting steps.

[0072] Further, as a preferred implementation of the present application, Figure 7 As shown, the upper substrate, the lower substrate and the visual camera are tilted as a whole, that is, the upper substrate, the lower substrate and the visual camera are parallel in their own vertical direction and centrally aligned, but are tilted synchronously as a whole, and the tilt angle is 10° to 45°.

[0073] S202: Acquire multiple characteristic patterns on the photographed substrate;

[0074] As a preferred embodiment of the present application, the characteristic pattern is a two-dimensional code, and the characteristic pattern is arranged in pairs. Specifically, the upper substrate and the lower substrate are pre-arranged with a two-dimensional code, and the setting method of the two-dimensional code is the existing technology, including but not limited to machining and laser processing, which is not described in detail in this application. Optionally, the characteristic pattern can be set to a visible type or an invisible type. When it is set to an invisible type, in step S201 of the present application, an auxiliary light source is used to illuminate the substrate so that the visual camera can capture the characteristic pattern.

[0075] Furthermore, as a feasible implementation method of the present application, obtaining the QR code characteristic pattern from the substrate photo also includes the following steps: first preprocessing the substrate photo to obtain a binary black-and-white image, and then traversing the pixel points of the black-and-white image to find the locator of the QR code, the locator is the square in the QR code, until three locators are found, that is, the range of the characteristic pattern is obtained.

[0076] S203: Analyze the characteristic pattern to obtain the relative error between the positions of the upper substrate and the lower substrate;

[0077] Specifically, when the range of the characteristic pattern on the substrate photo is obtained, the offset error of the lower substrate and the upper substrate is calculated by analyzing multiple characteristic patterns. As a feasible implementation method of the present application, this step is implemented by performing binocular visual ranging on multiple characteristic patterns:

[0078] First, the two visual cameras are calibrated using Zhang's calibration method to obtain the focal length f of the visual camera and the spacing b between adjacent visual cameras. Then, the positions of at least two characteristic patterns of the lower substrate are read and recorded as points P1 and P2.

[0079] Due to the parallax principle, point P1 has different imaging points on the two visual cameras, so the Z-axis distance from point P1 to the plane where the visual camera is located can be obtained:

[0080]

[0081] Among them, χL is the distance from the imaging point of point P1 on the left visual camera to the left imaging plane, and χR is the distance from the imaging point of point P1 on the right visual camera to the left imaging plane. Then we can get the X-axis and Y-axis coordinates of point P1:

[0082]

[0083] Among them, χ-χ0 is the x-distance between the two imaging points of point P1 on the two visual cameras, and y-y0 is the y-distance between the two imaging points of point P1 on the two visual cameras.

[0084] In the same way, the position of point P2 of the lower substrate can be read to obtain the three-dimensional coordinates of point P2, and the two coordinate points corresponding to points P1 and P2 can be connected to mark the position of the lower substrate through the vector.

[0085] In the same way, the two characteristic patterns of the upper substrate are read respectively, and the position of the upper substrate can be marked by two corresponding coordinate points, and then the relative error of the position of the upper substrate and the lower substrate is calculated, and the relative error includes lateral error, longitudinal error and rotation error.

[0086] S204: Move or rotate the upper substrate and the lower substrate to return the relative error to zero.

[0087] According to the relative error between the upper substrate and the lower substrate, correction is performed by moving or rotating the upper substrate and the lower substrate so that the centers of the upper substrate and the lower substrate coincide with each other in their vertical directions. Optionally, as a preferred embodiment of the present application, each time the moving or rotating operation of step S204 is performed, steps S201 to S203 are repeated again to obtain the relative error of the current upper substrate and the lower substrate again until the relative error returns to zero.

[0088] S300: gradually moving the upper substrate downward to make it close to the lower substrate;

[0089] Further, such as Figure 4 As shown, the step of gradually moving the upper substrate downward to make it close to the lower substrate includes:

[0090] S301: moving the upper substrate downward and detecting the distance between the upper substrate and the lower substrate;

[0091] When the upper substrate and the lower substrate are adjusted and aligned, the upper substrate is moved downward along the direction of the central axis of the upper substrate and the lower substrate, so that the upper substrate gradually approaches the lower substrate.

[0092] S302: Determine whether the distance is less than the safety distance;

[0093] Optionally, the safety distance is obtained by using a laser distance measuring sensor to accurately obtain the distance between the upper substrate and the lower substrate. As a preferred embodiment of the present application, the safety distance is 5 to 15 mm.

[0094] S303: When the distance is greater than the safety distance, the upper substrate continues to move downward;

[0095] S304: When the distance is less than or equal to the safety distance, the upper substrate is stopped from moving;

[0096] The advantage of this arrangement is that when the upper substrate and the lower substrate are less than the safety distance, further movement is stopped to prevent the upper and lower substrates from being squeezed and damaged. In addition, in this step, the precision requirement for moving the upper substrate is relatively low, so that the upper substrate can quickly approach the lower substrate, improving the efficiency of the bonding work.

[0097] S400: injecting circulating fluid to adjust the upper substrate and the lower substrate to a set temperature;

[0098] When the upper substrate is close to the lower substrate, circulating liquid is injected into the tank body where the upper substrate and the lower substrate are located. Specifically, according to the process requirements, when low-temperature processing is required, low-temperature circulating liquid is injected into the tank body, and when high-temperature processing is required, high-temperature circulating liquid is injected into the tank body, and the temperature change is monitored during the liquid injection process. When the temperature in the tank body does not reach the set temperature, new circulating liquid is continuously discharged and added until the set temperature is reached.

[0099] In this step, since there is a safety distance of 5 to 15 mm between the upper substrate and the lower substrate, the circulating liquid will gradually penetrate into and fill the gap between the upper substrate and the lower substrate, further improving the temperature control effect. The circulating liquid gradually enters the gap from the edge or corner of the upper substrate and the lower substrate. Compared with the flat setting that causes liquid to enter from all sides, the present application can gradually squeeze out the air in the gap and reduce the occurrence of bubbles.

[0100] S500: pressing the upper substrate and the lower substrate and performing a curing process;

[0101] As a preferred embodiment of the present application, the upper substrate and the lower substrate are pressed and cured, firstly, pressure is applied to push the upper substrate to make it fit with the lower substrate. Optionally, in the embodiment of the present application, the upper substrate can be pushed by an electric push rod or a cylinder, and pressure is applied to make the upper substrate fit with the lower substrate. The advantage of this step is that by replacing the high-precision stepping device, the upper substrate can be safely moved in a small amount and close to the lower substrate to prevent damage. Furthermore, when pushing the upper substrate, the change of pressure feedback is monitored, the pressure is controlled within the pressure range of the substrate, and a stable fit is maintained.

[0102] Then, an ultraviolet lamp is used to irradiate the upper substrate and the lower substrate to cure the optical glue between the upper substrate and the lower substrate. The irradiation time of the ultraviolet lamp is 2 to 10 seconds. Optionally, the present application is provided with multiple ultraviolet lamps and irradiation points to increase the curing speed and enhance the uniformity of curing. The cured optical glue combines the upper substrate and the lower substrate into a whole.

[0103] S600: taking out the upper substrate and the lower substrate that have been bonded.

[0104] Further, such as Figure 5As shown, the method of taking out the upper substrate and the lower substrate after bonding includes:

[0105] S601: Discharge the circulating fluid in the tank;

[0106] Specifically, the present application also monitors the liquid level changes in the tank where the upper substrate and the lower substrate are located through a liquid level sensor. When the curing work is completed, the circulating liquid in the tank is discharged. When the liquid level drops to the bottom of the tank, it is determined that it has been completely drained.

[0107] S602: Turn off the vacuum pump to stop the vacuum suction cup from adsorbing;

[0108] Specifically, in this step, the vacuum degree of the vacuum pumps corresponding to the upper substrate and the lower substrate is gradually reduced until the negative pressure is turned off to stop the vacuum suction cup from adsorbing.

[0109] S603: applying pre-pressure to the upper substrate and gradually withdrawing the vacuum chuck;

[0110] The advantage of this arrangement is that when the circulating liquid is injected into the tank body, part of the circulating liquid enters the gap between the substrate and the vacuum suction cup. Even if the vacuum pump is turned off to stop the negative pressure, the substrate will still be attached to the vacuum suction cup under the action of air pressure. If the vacuum suction cup is directly removed, the upper substrate is easily pulled out, and the upper and lower substrates that have been attached are pulled apart under the action of tension, or damage occurs due to uneven force. When the vacuum suction cup is removed, the S603 step applies pre-pressure to the upper substrate. Optionally, an electric push rod or a cylinder can be used to provide pressure to keep the upper and lower substrates fixed in place.

[0111] S604: taking out the upper substrate and the lower substrate that have been bonded.

[0112] This step is used to take out the upper substrate and the lower substrate that have been bonded in the tank body after the negative pressure is turned off and the vacuum suction cup is withdrawn.

[0113] Another embodiment of the present application provides a substrate very warm bonding system in liquid, which is applied to a substrate very warm bonding method in liquid, such as Figure 6 As shown, the system includes:

[0114] A fixing module 1, used for installing and fixing the upper base plate and the lower base plate respectively;

[0115] Alignment module 2, used for adjusting and aligning the upper substrate and the lower substrate;

[0116] A moving module 3, used for gradually moving the upper substrate downward to make it close to the lower substrate;

[0117] A cooling module 4 is used to inject circulating fluid to adjust the upper substrate and the lower substrate to a set temperature;

[0118] A curing module 5, used for pressing the upper substrate and the lower substrate and performing a curing process;

[0119] The exit module 6 is used to take out the upper substrate and the lower substrate that have been bonded.

[0120] As a feasible implementation mode of the present application, the fixing module 1, alignment module 2, moving module 3, cooling module 4, curing module 5 and exit module 6 described in this embodiment can be tangible physical devices or abstract modules having the working effect of the present application, including but not limited to a combination of software and hardware that realizes the function of the very warm bonding method of substrates in a liquid.

[0121] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying 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 application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection, an electrical connection, a direct connection, an indirect connection through an intermediate medium, or a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0122] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0123] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for bonding substrates in liquid at very low temperatures, characterized in that: The following steps are involved: S100: installing and fixing the upper base plate and the lower base plate respectively; S200: adjusting and aligning the upper substrate and the lower substrate; S300: gradually moving the upper substrate downward to make it close to the lower substrate; S400: injecting circulating fluid to adjust the upper substrate and the lower substrate to a set temperature; S500: pressing the upper substrate and the lower substrate and performing a curing process; S600: taking out the upper substrate and the lower substrate that have been bonded.

2. A method for bonding substrates in liquid at very low temperature according to claim 1, characterized in that: The above-mentioned steps of separately installing and fixing the upper substrate and the lower substrate include: S101, coating optical adhesive on the upper substrate and the lower substrate respectively; S102, placing the lower substrate in the tank, and placing the upper substrate above the lower substrate; S103, moving the upper substrate and the lower substrate to the vacuum suction cup respectively; S104, start the vacuum pump connected to the vacuum suction cup to absorb and fix the upper substrate and the lower substrate.

3. A method for bonding substrates in liquid at very low temperature according to claim 2, characterized in that: The lower substrate is placed in the tank body and the upper substrate is arranged above the lower substrate, which specifically includes: the upper substrate and the lower substrate are arranged in an inclined state, and the inclination angle is 10° to 45°.

4. The method for bonding substrates in liquid at very low temperature according to claim 1, characterized in that: The adjusting and aligning of the upper substrate and the lower substrate comprises: S201: Start the visual camera to take pictures of the upper substrate and the lower substrate; S202: Acquire multiple characteristic patterns on the photographed substrate; S203: Analyze the characteristic pattern to obtain the relative error between the positions of the upper substrate and the lower substrate; S204: Move or rotate the upper substrate and the lower substrate to return the relative error to zero.

5. The method for bonding substrates in liquid at very low temperature according to claim 4, characterized in that: The characteristic patterns are two-dimensional codes, and the characteristic patterns are arranged in pairs.

6. The method for bonding substrates in liquid at very low temperature according to claim 1, characterized in that: The step of gradually moving the upper substrate downward to make it close to the lower substrate comprises: S301: Move the upper substrate downward and detect the distance between the upper substrate and the lower substrate; S302: Determine whether the distance is less than the safety distance; S303: When the distance is greater than the safety distance, the upper substrate continues to move downward; S304: When the distance is less than or equal to the safety distance, the movement of the upper substrate is stopped.

7. A method for bonding substrates in liquid at very low temperature according to claim 6, characterized in that: The safety distance is 5 to 15 mm.

8. The method for bonding substrates in liquid at very low temperature according to claim 1, characterized in that: The pressing of the upper substrate and the lower substrate and the curing treatment specifically include: applying pressure to push the upper substrate to make it fit with the lower substrate, and then using an ultraviolet lamp to irradiate the upper substrate and the lower substrate to cure the optical glue between the upper substrate and the lower substrate, and the irradiation time of the ultraviolet lamp is 2 to 10 seconds.

9. The method for bonding substrates in liquid at very low temperature according to claim 1, characterized in that: The method of taking out the upper substrate and the lower substrate after bonding includes: S601: Discharge the circulating fluid in the tank; S602: Turn off the vacuum pump to stop the vacuum suction cup from adsorbing; S603: applying pre-pressure to the upper substrate and gradually withdrawing the vacuum chuck; S604: taking out the upper substrate and the lower substrate that have been bonded.

10. A substrate very warm bonding system in liquid, applied to a substrate very warm bonding method in liquid as claimed in claim 1 to claim 9, characterized in that: The system includes: A fixing module 1, used for installing and fixing the upper base plate and the lower base plate respectively; Alignment module 2, used for adjusting and aligning the upper substrate and the lower substrate; A moving module 3, used for gradually moving the upper substrate downward to make it close to the lower substrate; A cooling module 4 is used to inject circulating fluid to adjust the upper substrate and the lower substrate to a set temperature; A curing module 5, used for pressing the upper substrate and the lower substrate and performing a curing process; The exit module 6 is used to take out the upper substrate and the lower substrate that have been bonded.

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