Laminating method and laminating equipment

Abstract

The embodiment of the present application relates to the technical field of bonding, and provides a bonding method and a bonding device.The bonding method comprises the following steps: spraying water glue on a first object to be bonded, spraying water glue on a second object to be bonded, and arranging the water glue on the first object to be bonded and the water glue on the second object to be bonded to be face-to-face and spaced apart; under the action of high-voltage static electricity, the water glue on the first object to be bonded and the water glue on the second object to be bonded are directly contacted, and the first object to be bonded and the second object to be bonded are pressed.

Description

Technical Field

[0001] The present application relates to the field of lamination technology, and in particular to a lamination method and a lamination device. Background Art

[0002] The existing method of bonding two objects to be bonded (such as two glass substrates or two optical lenses) using water-based adhesive has problems with the appearance quality and optical image quality of the bonded product. Summary of the Invention

[0003] A first aspect of the present application provides a bonding method, the bonding method comprising:

[0004] Spraying water-based glue on a first object to be bonded, and spraying water-based glue on a second object to be bonded, with the water-based glue on the first object to be bonded and the water-based glue on the second object to be bonded facing each other and spaced apart;

[0005] bringing the hydrogel on the first object to be bonded and the hydrogel on the second object to be bonded into direct contact under the action of high-voltage static electricity; and

[0006] The first object to be bonded and the second object to be bonded are pressed together.

[0007] In traditional lamination methods, water-based glue is sprayed only on the first object to be laminated. After the glue dispensing process, the second object to be laminated is directly pressed down to laminate with the first object to be laminated. This can easily lead to appearance quality issues such as bubbles in the center area of ​​the laminated product, as well as optical image quality issues. In the lamination method of the first aspect of the present application, water-based glue is sprayed on both the first and second objects to be laminated. The water-based glue on the first and second objects to be laminated, in addition to providing bonding during the lamination step, also serves to pre-contact them under high-voltage static electricity before the lamination step, thereby reducing the probability of bubbles forming in the center area of ​​the laminated product and ensuring the optical image quality of the laminated product.

[0008] In a second aspect of the present application, a bonding device is provided for bonding a first object to be bonded to a second object to be bonded using a water-based adhesive. The bonding device comprises:

[0009] a first glue dispensing device, used for fixing the first object to be bonded and spraying water-based glue onto the first object to be bonded;

[0010] a second glue dispensing device, configured to fix the second object to be bonded and spray the water-based glue onto the second object to be bonded, wherein at least one of the first glue dispensing device and the second glue dispensing device comprises a flipping mechanism so that the water-based glue on the first object to be bonded and the water-based glue on the second object to be bonded face each other and are spaced apart;

[0011] a high-voltage static electricity generating device, used to make the hydrogel on the first object to be bonded and the hydrogel on the second object to be bonded directly contact under the action of high-voltage static electricity; and

[0012] A pressing device is used for pressing the first object to be bonded and the second object to be bonded.

[0013] The bonding equipment of the second aspect of the present application has the same advantages as the bonding method described in the first aspect, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the steps of the traditional bonding method.

[0015] Figure 2 Schematic diagram of the appearance quality of the product obtained by the traditional bonding method.

[0016] Figure 3 Schematic diagram of optical imaging test of products obtained by traditional bonding method.

[0017] Figure 4 This is a flow chart of a bonding method according to an embodiment of the present application.

[0018] Figure 5 for Figure 4 Schematic diagram of the structure of step S1 in FIG.

[0019] Figure 6 for Figure 4 Schematic diagram of the structure of step S2 in FIG.

[0020] Figure 7 for Figure 4 Schematic diagram of the structure of step S3 in FIG.

[0021] Figure 8 Schematic diagram of a three-dimensional scan of a product obtained by using the bonding method of one embodiment of the present application.

[0022] Figure 9 Schematic diagram of the appearance quality of a product obtained by using the bonding method according to one embodiment of the present application.

[0023] Figure 10 Schematic diagram of an optical image test of a product obtained by using the bonding method according to an embodiment of the present application.

[0024] Figure 11 This is a structural diagram of a bonding device according to an embodiment of the present application.

[0025] Description of main component symbols:

[0026] First objects to be bonded 10, 10'

[0027] First surfaces to be bonded 11, 11'

[0028] Second objects to be bonded 20, 20'

[0029] Second surfaces to be bonded 21, 21'

[0030] Water glue 30, 30'

[0031] Laminating equipment 100

[0032] First dispensing device 110

[0033] Second dispensing device 120

[0034] High-voltage static electricity generating device 130

[0035] Pressing device 140

[0036] Thickness detection device 150

[0037] Nozzle N, N'

[0038] Power supply P

[0039] Electrodes E1, E2

[0040] Bubble a

[0041] Dot or line shadingb

[0042] Total thickness D

[0043] End surface S

[0044] Steps S1, S2, and S3 DETAILED DESCRIPTION

[0045] Today, the water-based adhesive bonding process is widely used in the bonding and assembly of 3C electronic products. Figure 1 Schematic diagram of the steps of the traditional bonding method. Figure 1 Figures (a) and (b) are respectively a top view and a side view of the first object to be bonded. Figure 1 Figure (c) is a schematic diagram of spraying water glue on the first object to be bonded. Figure 1 Figure (d) is a schematic diagram of pressing the second object to be bonded and the first object to be bonded. Figure 1 Figure (e) is a schematic diagram of the product obtained after the bonding is completed. The following description is made by taking the first object to be bonded and the second object to be bonded as flat glass plates as an example.

[0046] like Figure 1 As shown in (a) and (b) of FIG. 1 , the first object to be bonded 10' is roughly rectangular and includes a first bonding surface 11'. The first bonding surface 11' is a plane. Figure 1As shown in FIG. (c), in the conventional bonding method, a certain amount of water glue 30' in the glue tube is usually dripped onto the first bonding surface 11' of the first object 10' by using a nozzle N'. Figure 1 As shown in Figure (d), another second object to be bonded 20' is placed on top of the first object to be bonded 10', and the second bonding surface 21' of the second object to be bonded 20' is placed face to face with the first bonding surface 11' of the first object to be bonded 10'. Then, gently push until the first object to be bonded 10' and the second object to be bonded 20' are completely bonded, and finally the water glue is cured to complete the entire bonding process. Figure 1 The product shown in Figure (e) in the figure. If you need to control the total thickness of the product after bonding, you need to set the pressing distance during the bonding process in advance according to the set dimensions of the product drawing.

[0047] However, the conventional bonding method has the following problems. First, due to the existence of dimensional tolerances of the products to be bonded (i.e. the first object to be bonded 10' and the second object to be bonded 20'), it is easy to cause the bonded products to have the following problems: Figure 2 The glue shortage problem shown in Figure (a) or Figure 2 The problem of glue overflow is shown in Figure (b). Secondly, the traditional bonding method is prone to the following problems in the center area of ​​the bonded product: Figure 2 Thirdly, due to the dimensional tolerance of the objects to be bonded (i.e., the first object to be bonded 10' and the second object to be bonded 20'), the traditional bonding method cannot accurately control the total thickness D of the bonded product, where the total thickness D is shown in FIG. Figure 1 In Figure (e), the total thickness D is the distance from the upper surface of the first object to be bonded 10' to the lower surface of the second object to be bonded 20'. The upper surface of the first object to be bonded 10' is the surface of the first object to be bonded 10' opposite to the first bonding surface 11'; the lower surface of the second object to be bonded 20' is the surface of the second object to be bonded 20' opposite to the second bonding surface 21'. Fourthly, in the traditional bonding method, when the bonded product is tested for optical image quality, linear or dot shadows will appear on the optical pattern, such as Figure 3 There is a linear or dotted shadow b within the range selected by the two dotted lines.

[0048] In summary, the products bonded by the traditional water-based bonding method have appearance quality issues (such as glue deficiency, glue overflow, center bubbles, and inability to accurately control the total thickness of the bonded product, etc.) and optical image quality issues (when the bonded product is subjected to optical image quality testing, poor linear or dot-shaped shadows will appear on the optical pattern, etc.), resulting in a loss in the yield of the bonded products.

[0049] To address this issue, embodiments of the present application provide a bonding method. The bonding method includes spraying a water-based adhesive onto a first object to be bonded, spraying a water-based adhesive onto a second object to be bonded, and positioning the water-based adhesive on the first object to be bonded and the water-based adhesive on the second object to be bonded face to face and spaced apart; placing the water-based adhesive on the first object to be bonded and the water-based adhesive on the second object to be bonded in direct contact under the action of high-voltage static electricity; and pressing the first and second objects to be bonded together.

[0050] In traditional lamination methods, water-based adhesive is sprayed only on the first object to be bonded. After the adhesive dispensing process, the second object to be bonded is directly pressed down to bond with the first object to be bonded. This can easily lead to appearance quality issues such as bubbles in the center area of ​​the bonded product, as well as optical image quality issues. In this lamination method, water-based adhesive is sprayed on both the first and second objects to be bonded. The water-based adhesive on the first and second objects not only serves as a bonding agent during the lamination step but also serves as a pre-contact mechanism under high-voltage static electricity before the lamination step. This reduces the likelihood of bubbles forming in the center area of ​​the bonded products and ensures the optical image quality of the resulting bonded products.

[0051] The technical solutions 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 only part of the embodiments of the present application, not all of the embodiments.

[0052] like Figure 4 As shown, the bonding method according to one embodiment of the present application includes the following steps S1 to S3.

[0053] Step S1: spraying water-based glue on a first object to be bonded, and spraying water-based glue on a second object to be bonded, and making sure that the water-based glue on the first object to be bonded and the water-based glue on the second object to be bonded are face to face and spaced apart.

[0054] In some embodiments, the surface to be bonded of the first object to be bonded and the surface to be bonded of the second object to be bonded are both flat surfaces. In other embodiments, the surface to be bonded of the first object to be bonded and the surface to be bonded of the second object to be bonded are both curved surfaces, or one of them is a curved surface and the other is a flat surface.

[0055] Specifically, the first object to be bonded and the second object to be bonded may both be flat glass plates; or, one of the first object to be bonded and the second object to be bonded may be a cover plate, and the other may be a display screen; or, one of the first object to be bonded and the second object to be bonded may be a cover plate, and the other may be a touch screen; or, one of the first object to be bonded and the second object to be bonded may be a display screen, and the other may be a touch screen; or, both the first object to be bonded and the second object to be bonded may be optical lens modules, but the present invention is not limited thereto.

[0056] The following figures illustrate an example in which both the first and second objects to be bonded are flat glass plates. Step S1 includes the following steps S11 to S18. Depending on different requirements, the order of some steps in steps S11 to S18 may be changed, and some steps may be omitted or combined.

[0057] Step S11: Degassing the water-based adhesive to be sprayed.

[0058] Specifically, the water glue is, for example, liquid optical glue, but is not limited thereto. The raw material of the water glue used in the bonding equipment (also known as the bonding machine) is usually a replaceable large tube package. When in use, a new tube of glue is installed in the reserved position of the bonding equipment, which can continuously provide water glue for the machine pipeline. However, after the water glue is filled and shipped from the manufacturer, it goes through the packaging, transportation and other processes, and tiny bubbles will inevitably appear inside the water glue. By degassing the water glue before loading it into the bonding equipment, it can be avoided that the tiny bubbles in the water glue remain, resulting in the appearance of over-specification center bonding bubbles in the product after bonding.

[0059] In some embodiments, in step S11 , high temperature and high pressure are used to degas the sprayed water glue, with the temperature ranging from 40° C. to 60° C. and the pressure ranging from 0.5 MPa to 0.8 MPa, but not limited thereto.

[0060] In some other embodiments, heating may not be performed in step S11 , that is, high pressure is used to degas the water-based adhesive to be sprayed, and the pressure range is, for example, 0.5 MPa to 0.8 MPa, but is not limited thereto.

[0061] Step S12: exhaust the machine pipeline.

[0062] Specifically, when the previous tube of glue in the laminating equipment is depleted and replaced with a new one, some disconnection in the machine piping is inevitable. Therefore, after removing the previous tube of glue, the old glue in the machine piping is first drained. After replacing the new tube of glue, a dry run is performed to remove all air from the machine piping. Therefore, step S12 also helps prevent tiny bubbles in the glue from remaining, which can lead to excessive center lamination bubbles in the finished product.

[0063] Step S13: Fix the first object to be bonded and simultaneously measure the thickness of the first object to be bonded.

[0064] Specifically, the laminating apparatus includes a first adhesive dispensing device and a thickness detection device. The first adhesive dispensing device, for example, includes a first jig for supporting the first object to be laminated. The thickness detection device, for example, includes a charge-coupled device (CCD) camera. In some embodiments, step S13 includes securing the first object to be laminated to the first jig and synchronously measuring the thickness D1 of the first object to be laminated at different locations using the CCD camera.

[0065] Step S14: fixing the second object to be bonded and synchronously measuring the thickness of the second object to be bonded.

[0066] Specifically, the laminating apparatus further includes a second glue dispensing device. The second glue dispensing device, for example, includes a second jig for supporting the second object to be laminated. The thickness detection device is further configured to measure the thickness of the second object to be laminated at various locations. In some embodiments, step S14 includes securing the second object to be laminated to the second jig and synchronously measuring the thickness D2 of the second object to be laminated at various locations using a CCD camera.

[0067] Step S15: Calculating the amount of water-based glue to be sprayed onto the first object to be bonded and the amount of water-based glue to be sprayed onto the second object to be bonded.

[0068] In some embodiments, the thickness detection device is also used to measure the total thickness of the first object to be laminated, the water-based adhesive, and the second object to be laminated after lamination. In step S15, the amount of water-based adhesive to be sprayed on the first object to be laminated and the amount of water-based adhesive to be sprayed on the second object to be laminated are calculated based on the thickness of the first object to be laminated at different locations, the thickness of the second object to be laminated at different locations, the desired thickness of the product after lamination, and the lamination area.

[0069] Specifically, Adaptive Dispense Control (ADC) technology (also known as adaptive dispensing control technology) detects the desired thickness of the product after lamination and calculates in real time the amount of water-based glue V1 to be sprayed on the first object to be laminated and the amount of water-based glue V2 to be sprayed on the second object to be laminated, thereby fundamentally reducing the risk of glue shortage and / or glue overflow. Taking the first and second objects to be laminated as rectangular and fully laminated as an example, the calculation formula and logic of V1 and V2 are as follows: V1 + V2 = (D0 – D1 – D2) × L × W. Where L is the length of the first object to be laminated; W is the width of the first object to be laminated; and D0 is the desired thickness of the product after lamination (also known as the thickness specified in the drawing after product lamination).

[0070] In other embodiments, the shapes of the first object to be bonded and the second object to be bonded can be changed. For example, the first object to be bonded and the second object to be bonded are two lenses, the surface to be bonded of the first object to be bonded is a concave surface, and the surface to be bonded of the second object to be bonded is a convex surface. In this case, V1+V2=(D0–D1–D2)×A, where A is the area of ​​the bonding surface of the first object to be bonded and the second object to be bonded.

[0071] Step S16: spraying water-based adhesive on the first object to be bonded.

[0072] Specifically, the first glue dispensing device also includes a nozzle connected to the machine pipeline and used to spray the water glue onto the first object to be bonded. Figure 5 As shown in FIG. 1 (a), the first object to be bonded 10 includes a first bonding surface 11. A nozzle N sprays water-based adhesive 30 onto the first bonding surface 11 of the first object to be bonded 10.

[0073] In some embodiments, to ensure that the water glue can be evenly spread when the first and second objects are subsequently pressed together, the laminating method of the embodiment of the present application further includes designing a pattern formed when spraying the water glue on the first object to be laminated, based on the size of the first object to be laminated, the viscosity of the water glue, and the pressing speed when pressing the first and second objects to be laminated together. Figure 5 As shown in FIG. 1 (b), the hydrogel 30 sprayed on the first object to be bonded 10 is in the shape of a radial four-pointed star. In other embodiments, the initial shape of the hydrogel sprayed on the first object to be bonded can be simulated by fluid dynamics analysis software (e.g., ANSYS Fluent), but is not limited thereto.

[0074] In addition, to ensure that the needle tip of the nozzle during the glue spraying process does not bury into the interior of the colloid sprayed onto the first object to be bonded, and to avoid the appearance of poor dotted or line-shaped shadows in the optical pattern obtained during the optical quality test of the bonded product (especially for bonding of curved surfaces and complex paths), the bonding equipment can be set so that the nozzle for spraying the water-based glue always maintains a first preset distance from the first object to be bonded based on the input parameters and does not bury into the water-based glue sprayed onto the first object to be bonded. That is, the nozzle can always maintain the same distance from the surface to be bonded of the first object to be bonded according to the fluctuations of the surface to be bonded of the first object to be bonded, and will not bury into the already sprayed colloid. It can be understood that the distance between the nozzle and the surface to be bonded of the first object to be bonded is greater than the volume V1 of the sprayed water-based glue divided by the area A of the bonding surface.

[0075] Step S17: spraying water-based adhesive on the second object to be bonded.

[0076] Specifically, the second glue dispensing device also includes a nozzle connected to the machine pipeline and used to spray the water glue onto the second object to be bonded. Figure 5 As shown in Figure (c), the second object to be bonded 20 includes a second surface to be bonded 21. The order of steps S16 and S17 can be adjusted. For example, if step S16 is first performed to spray a volume of water glue V1 on the first object to be bonded, the volume V2 of the water glue to be sprayed on the second object to be bonded in step S17 is calculated according to the calculation formula V1+V2=(D0–D1–D2)×A in step S15. Similarly, if step S17 is first performed to spray a volume of water glue V2 on the second object to be bonded, the volume V1 of the water glue to be sprayed on the first object to be bonded in step S16 is calculated according to the calculation formula V1+V2=(D0–D1–D2)×A in step S15.

[0077] Similarly, to ensure that the needle tip of the spray nozzle does not bury itself in the colloid sprayed onto the second object to be bonded during the glue spraying process, and to avoid poor dot-shaped or line-shaped shadows in the optical pattern obtained during the optical quality test of the bonded product (especially for curved surface bonding and complex path bonding), the bonding equipment can be configured so that the nozzle spraying the water-based glue always maintains a second preset distance from the second object to be bonded and does not bury itself in the water-based glue sprayed onto the second object to be bonded. That is, the nozzle can always maintain the same distance from the surface to be bonded of the second object to be bonded according to the fluctuations of the surface to be bonded of the first object to be bonded, and will not bury itself in the already sprayed colloid. It can be understood that the distance between the nozzle and the surface to be bonded of the second object to be bonded is greater than the volume V2 of the sprayed water-based glue divided by the area A of the bonding surface.

[0078] In some embodiments, the volume V2 of the water-based adhesive sprayed on the second object to be bonded is smaller than the volume V1 of the water-based adhesive sprayed on the first object to be bonded. The water-based adhesive sprayed on the first object to be bonded primarily serves as a bonding agent in the subsequent lamination step and forms the bulk of the bonded product. The water-based adhesive sprayed on the second object to be bonded primarily serves to generate high-voltage static electricity between the first and second objects to be bonded in subsequent steps, allowing the water-based adhesive on the first and second objects to be bonded to directly contact each other due to the tip discharge effect.

[0079] Specifically, the laminating equipment controls the amount of glue dispensed by controlling the distance the pressure head in the nozzle is advanced. For example, a drop of adhesive can be applied to the second object to be bonded. The volume V2 can be calculated from the distance the pressure head has advanced. V1 is then calculated using the formula V1+V2=(D0–D1–D2)×A, and converted to the distance the pressure head needs to advance to spray the adhesive on the first object to be bonded.

[0080] Step S18: The water-based adhesive on the first object to be bonded and the water-based adhesive on the second object to be bonded are arranged face to face and spaced apart.

[0081] At least one of the first and second dispensing devices includes a flipping mechanism to position the adhesive on the first object to be bonded and the adhesive on the second object to be bonded face-to-face and spaced apart. In some embodiments, the second dispensing device includes a flipping mechanism that controls the second fixture to position the second bonding surface 21 of the second object to be bonded 20 face-to-face with the first bonding surface 11 of the first object to be bonded 10. Because the volume V2 of the adhesive on the second object to be bonded 20 is very small and the adhesive has a certain viscosity, the adhesive 30 on the second object to be bonded 20 will not drip due to gravity.

[0082] Step S2: The hydrogel on the first object to be bonded and the hydrogel on the second object to be bonded are brought into direct contact under the action of high-voltage static electricity.

[0083] Specifically, after the dispensing is completed, a high voltage bonding (HV bonding) process is performed. The bonding equipment also includes a high voltage static electricity generating device, which is used to make the hydrogel on the first object to be bonded and the hydrogel on the second object to be bonded directly contact under the action of high voltage static electricity. The high voltage static electricity generating device includes a high voltage DC power supply P, a first electrode E1 and a second electrode E2. Figure 6 As shown, the first electrode E1 and the second electrode E2 are electrically connected to the positive and negative electrodes of a high-voltage DC power supply P, respectively. The first electrode E1 is located on the surface of the first object to be bonded 10 opposite the first bonding surface 11, and the second electrode E2 is located on the surface of the second object to be bonded 20 opposite the second bonding surface 21. The high-voltage DC power supply P applies high-voltage DC power between the first object to be bonded 10 and the second object to be bonded 20, forming a high-voltage electrostatic field between the first object to be bonded 10 and the second object to be bonded 20. Utilizing the tip discharge effect, the hydrogel 30 on the first object to be bonded 10 and the hydrogel 30 on the second object to be bonded 20 are brought into contact with each other immediately, and the subsequent lamination step begins.

[0084] It should be noted that tip discharge is a type of corona discharge. Corona discharge is a process in which an electric current flows from a charged object (electrode) to an uncharged fluid, thereby causing ionized molecules to form near the electrode. Tip discharge specifically refers to the corona discharge phenomenon caused by a pointed object in corona discharge. The air near the pointed object is ionized due to the very high electric field. Ionic molecules have conductivity, so ionized air can be regarded as a conductor. Therefore, originally only the pointed object was a conductor, but now it is surrounded by ionized air. As the range of the conductor increases, the electric field will become lower, until it is so low that the air cannot be freed. The air will no longer be freed, and the range of free air will no longer increase. Therefore, the range of tip discharge will be affected by the size of the electric field, that is, it will be affected by the shape of the pointed object.

[0085] The tip effect refers to the phenomenon in which, on a charged conductor, the surface charge density at the tip is greater than at the smoother portion, leading to a stronger electric field near the tip and a tendency for discharge to occur from the tip into the surrounding air or a nearby grounded object. Under the strong electric field at the tip of a charged conductor, the remaining ions in the air nearby move violently and collide violently with air molecules, ionizing them and generating a large number of positive and negative ions. These ions, in turn, collide with other air molecules under the influence of the electric field, further ionizing them. This cycle continues, creating a tip discharge.

[0086] Furthermore, in air, tip discharges are often observed near the tip of a high-voltage conductor. However, even if a charged object has no tip, a tip effect can occur if a nearby grounded conductor has a tip. In this case, electrostatic induction induces an opposite charge at the tip of the grounded object, making it more likely for a discharge to occur between the charged object and the tip.

[0087] Specifically in the bonding method of the embodiment of the present application, although the hydrogel is not necessarily a conductor, since the volume of the hydrogel on the second object to be bonded is very small (such as a drop), a tip is formed on the second object to be bonded. When a high-voltage power supply is applied between the first object to be bonded and the second object to be bonded, a very high electric field is formed between the first object to be bonded and the second object to be bonded. Under the action of this high electric field, the hydrogel on the second object to be bonded will act as a discharge tip and come into contact with the hydrogel on the second object to be bonded.

[0088] In some embodiments, in step S16, the water-based adhesive is sprayed on the central region of the first object to be bonded, and in step S17, the water-based adhesive is sprayed on the central region of the second object to be bonded. In step S2, during the high-pressure bonding process, the water-based adhesive in the central region of the first object to be bonded and the water-based adhesive in the central region of the second object to be bonded are ensured to be in direct contact with each other. This helps prevent the formation of central bubbles during the subsequent lamination process.

[0089] Step S3: Pressing the first object to be bonded and the second object to be bonded.

[0090] Specifically, after the hydrogel 30 on the first object to be bonded 10 and the second object to be bonded 20 are pre-contacted, a pressing step may be performed.

[0091] In some embodiments, the thickness detection device of the laminating device is further used to measure the total thickness of the first object to be laminated, the hydrogel, and the second object to be laminated after lamination. Specifically, step S3 includes the following steps S31 to S33.

[0092] Step S31: pressing the first object to be bonded and the second object to be bonded.

[0093] Step S32: Detect whether the total thickness of the first object to be bonded, the hydrogel and the second object to be bonded is within a preset range.

[0094] Step S33: If the total thickness is not within the preset range, repeat steps S31 and S32 until the total thickness is within the preset range.

[0095] Specifically, the laminating device may include a pressing device for pressing the first object to be laminated and the second object to be laminated. In step S31, the pressing device can control the second jig to press downward toward the first jig, so that the second object to be laminated 20 moves toward the first object to be laminated 10 and the hydrogel 30 between the two is dispersed.

[0096] In addition, in the laminating device, the thickness detection device is also used to measure the total thickness of the first object to be laminated, the water glue, and the second object to be laminated after lamination. That is, the laminating method, by adopting the automatic thickness control (ATC) technology, can monitor the thickness of the first object to be laminated in real time, so as to adjust the position of the nozzle in real time, ensure that the distance between the nozzle and the surface to be laminated of the first object to be laminated is constant, and will not be buried in the water glue sprayed on the first object to be laminated due to the fluctuation of the surface to be laminated of the first object to be laminated. Similarly, by adopting the ATC technology, the thickness of the second object to be laminated can be monitored in real time, so as to adjust the position of the nozzle in real time, ensure that the distance between the nozzle and the surface to be laminated of the second object to be laminated is constant, and will not be buried in the water glue sprayed on the second object to be laminated due to the fluctuation of the surface to be laminated of the second object to be laminated.

[0097] In step S32, ATC technology is used to monitor the total thickness of the first object to be laminated, the water-based adhesive, and the second object to be laminated in real time after lamination. This allows calculation of the lamination distance and ensures that the thickness of the final laminated product meets a predetermined tolerance. The predetermined tolerance can be the thickness D0 of the desired laminated product.

[0098] Specifically, if after laminating the first and second objects to be laminated, the total thickness D of the first object to be laminated, the hydrogel, and the second object to be laminated is detected to be within a preset range, the hydrogel between the first and second objects to be laminated is cured. Otherwise, step S31 is executed again, the first and second objects to be laminated are laminated, and the laminating distance ΔD is D-D0. After laminating, step S32 is executed again to detect the total thickness of the first object to be laminated, the hydrogel, and the second object to be laminated, and determine whether the total thickness meets the requirements. Once the total thickness D is within the tolerance range specified by D0, the hydrogel between the first and second objects to be laminated is cured.

[0099] In some embodiments, the laminating device includes a light-curing device. The water-based adhesive curing step can be performed by ultraviolet (UV) irradiation, causing the water-based adhesive to undergo internal chemical reactions and cross-linking, thereby achieving the final shape and adhesive strength. In other embodiments, the laminating device includes a heat-curing device. The water-based adhesive curing step can be performed by the heat-curing device.

[0100] Specifically, after curing, the following Figure 7 In the product shown, the first object to be bonded 10 and the second object to be bonded 20 are bonded by the cured water-based adhesive 30 .

[0101] like Figure 8 As shown in FIG. (a), the three-dimensional scanning result obtained by optical imaging test of the bonded product shows that the thickness of the cured water glue 30 in the bonded product is uniform. In addition, Figure 8 In FIG. (b), the horizontal axis represents the distance from the surface of the first object to be bonded 10 away from the first bonding surface 11 to the second object to be bonded 20 away from the second bonding surface 21. The vertical axis represents the boundary of the bonded product (i.e. Figure 7 The fluctuation of the end surface S) in the first object to be bonded 10, the edge of the cured water glue 30, and the edge of the second object to be bonded 20 are greater than 0 if they extend beyond the reference plane, otherwise they are less than 0. Figure 8 As can be seen in Figure (b), the edge fluctuation of the cured water-based adhesive 30 is generally within the range of ±10 microns. Therefore, the product obtained by the bonding method of the embodiment of the present application has a smooth edge without obvious adhesive deficiency or adhesive overflow.

[0102] from Figure 9 It can be seen that the product obtained by the bonding method of the embodiment of the present application has no bubbles in the center of the product that exceed the specifications. Figure 10 It can be seen that when the optical image quality test is performed on the well-bonded product, there are no wireless or dot-shaped shadow defects in the area selected by the two dotted lines on the optical pattern.

[0103] In summary, the bonding method of the embodiment of the present application ensures the appearance quality and optical quality of the bonded product from the following multiple aspects. First, by pre-treating the original glue material and exhausting the machine pipeline in the bonding device before dispensing, it is ensured that there is no bubble connection after the machine is changed, which is conducive to avoiding the generation of central bubbles in the product obtained after bonding. Second, by designing the dispensing pattern sprayed on the first object to be bonded, it is conducive to ensuring that the water glue is evenly extended during the lamination process. Third, by optimizing the height of the nozzle during the dispensing process, it is conducive to ensuring that the nozzle will not be buried in the colloid that has been sprayed during the gluing process, which is conducive to ensuring that the subsequent bonded product has no problems of poor linear or dotted shadows on the optical pattern when performing optical image quality testing. Fourth, by using automatic thickness control technology, by detecting the actual thickness of the first object to be bonded, the water glue and the second object to be bonded laminate after lamination, the distance required to be pressed is accurately calculated in real time, and the steps of pressing and detecting are repeated until the total thickness D value finally measured is within the tolerance range allowed by the D0 specification. Fifth, after dispensing is complete, a high-pressure bonding process is performed, utilizing the tip effect for pre-contact bonding of the adhesive. This ensures that the centers of the two objects to be bonded are immediately in contact before the pressing step begins. Sixth, adaptive dispensing control technology is employed to accurately calculate the volume of adhesive sprayed on the first and second objects in real time by detecting the actual thickness of the first and second objects to be bonded. This facilitates precise control of the thickness of the bonded product.

[0104] The present application also provides a bonding device for bonding a first object to be bonded and a second object to be bonded by means of a water-based adhesive. The above bonding method can be run on the bonding device. Figure 11 As shown, the bonding device 100 includes a first dispensing device 110 , a second dispensing device 120 , a high-voltage static electricity generating device 130 , a pressing device 140 and a thickness detecting device 150 .

[0105] The first dispensing device 110 is used to secure the first object to be bonded and spray the adhesive onto it. The first dispensing device 110, for example, includes a first fixture (not shown) for securing the first object to be bonded and a first nozzle (not shown) connected to the machine piping and configured to spray the adhesive onto the first object. In some embodiments, the first nozzle maintains a consistent distance from the first object while spraying the adhesive, thereby minimizing appearance and optical quality issues in the bonded product.

[0106] The second dispensing device 120 is used to secure the second object to be bonded and spray the adhesive onto it. The second dispensing device 120, for example, includes a second fixture (not shown) for securing the second object to be bonded and a second nozzle (not shown) connected to the machine piping and configured to spray the adhesive onto the second object. In some embodiments, the second nozzle maintains a consistent distance from the second object while spraying the adhesive, thereby minimizing appearance and optical quality issues in the bonded product.

[0107] At least one of the first glue dispensing device 110 and the second glue dispensing device 120 includes a flipping mechanism (not shown) so that the water-based glue on the first object to be bonded and the water-based glue on the second object to be bonded are face to face and spaced apart.

[0108] The high-voltage electrostatic generating device 130 is used to make the hydrogel on the first object to be bonded and the hydrogel on the second object to be bonded directly contact under the action of high-voltage static electricity. The high-voltage electrostatic generating device 130 includes a high-voltage DC power supply and electrodes connected to the high-voltage DC power supply.

[0109] The pressing device 140 is used to press the first object to be bonded and the second object to be bonded together. The pressing device 140 drives the second fixture to press down, so that the first object to be bonded and the second object to be bonded are bonded to each other.

[0110] The thickness detection device 150 is used to measure the thickness of the first object to be bonded at different locations, the thickness of the second object to be bonded at different locations, and the total thickness of the first object to be bonded, the hydrogel, and the second object to be bonded after lamination. The thickness detection device 150 includes, for example, a CCD camera, but is not limited thereto.

[0111] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent replacements of the technical solutions of the present application should not depart from the spirit and scope of the technical solutions of the present application.

Claims

1. A laminating method, characterized in that: include: Spraying water-based glue on a first object to be bonded, and spraying water-based glue on a second object to be bonded, with the water-based glue on the first object to be bonded and the water-based glue on the second object to be bonded facing each other and spaced apart; The hydrogel on the first object to be bonded and the hydrogel on the second object to be bonded are brought into direct contact under the action of high-voltage static electricity; as well as The first object to be bonded and the second object to be bonded are pressed together.

2. The laminating method according to claim 1, wherein: Spraying the water-based adhesive on the first object to be bonded includes spraying the water-based adhesive on a middle area of ​​the first object to be bonded; Spraying the water-based adhesive on the second object to be bonded includes spraying the water-based adhesive on a middle region of the second object to be bonded; The volume of the water glue sprayed on the second object to be bonded is smaller than the volume of the water glue sprayed on the first object to be bonded.

3. The laminating method according to claim 1, wherein: The bonding method further comprises: Before spraying the water-based adhesive on the first object to be bonded, measuring the thickness of the first object to be bonded at different positions; Before spraying the water-based adhesive on the second object to be bonded, measuring the thickness of the second object to be bonded at different positions; and The amount of water glue to be sprayed onto the first object to be bonded and the amount of water glue to be sprayed onto the second object to be bonded are calculated based on the thickness at different locations of the first object to be bonded, the thickness at different locations of the second object to be bonded, the thickness of the desired product after bonding, and the bonding area.

4. The laminating method according to claim 1, wherein: The bonding method further comprises: After laminating the first object to be laminated and the second object to be laminated, detecting whether the total thickness of the first object to be laminated, the hydrogel and the second object to be laminated is within a preset range; If the total thickness is not within the preset range, the first object to be bonded and the second object to be bonded are continuously pressed together until the total thickness is within the preset range.

5. The laminating method according to claim 1, wherein: When spraying the water-based adhesive on the first object to be bonded, the nozzle for spraying the water-based adhesive always maintains a first preset distance from the first object to be bonded and does not bury in the water-based adhesive sprayed on the first object to be bonded; and / or When spraying the water glue on the second object to be bonded, the nozzle for spraying the water glue always maintains a second preset distance from the second object to be bonded and will not be buried in the water glue sprayed on the second object to be bonded.

6. The laminating method according to claim 1, wherein: The bonding method further comprises: The pattern formed when spraying the water glue on the first object to be bonded is designed according to the size of the first object to be bonded, the viscosity of the water glue, and the pressing speed when the first object to be bonded and the second object to be bonded are pressed together.

7. The laminating method according to any one of claims 1 to 6, wherein: Before spraying the water-based adhesive on the first object to be bonded and / or before spraying the water-based adhesive on the second object to be bonded, the bonding method further includes: Degassing of the water-based adhesive to be sprayed; and / or When the water-based glue in the machine pipeline needs to be replaced, the machine pipeline is vented.

8. A bonding device for bonding a first object to be bonded and a second object to be bonded by means of a water-based adhesive, characterized in that: The laminating equipment includes: a first glue dispensing device, used for fixing the first object to be bonded and spraying water-based glue onto the first object to be bonded; a second glue dispensing device, configured to fix the second object to be bonded and spray the water-based glue onto the second object to be bonded, wherein at least one of the first glue dispensing device and the second glue dispensing device comprises a flipping mechanism so that the water-based glue on the first object to be bonded and the water-based glue on the second object to be bonded face each other and are spaced apart; a high-voltage static electricity generating device, used to make the hydrogel on the first object to be bonded and the hydrogel on the second object to be bonded directly contact under the action of high-voltage static electricity; and A pressing device is used for pressing the first object to be bonded and the second object to be bonded.

9. The laminating device according to claim 8, wherein: The laminating equipment further includes a thickness detecting device, which is used to measure the thickness of the first object to be laminated at different positions, the thickness of the second object to be laminated at different positions, and the total thickness of the first object to be laminated, the hydrogel, and the second object to be laminated after lamination.

10. The laminating device according to claim 8 or 9, characterized in that: The first glue dispensing device includes a first nozzle, and the first nozzle can always maintain a same distance from the first object to be bonded when spraying the water-based glue on the first object to be bonded; The second glue dispensing device includes a second nozzle, and the second nozzle can always maintain a same distance from the second object to be bonded when spraying the water-based glue on the second object to be bonded.

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