Method for bonding touch display device

Abstract

The application relates to a laminating method of a touch display device, comprising the following steps: providing a display module and a touch panel; laminating the display module and the touch panel through an optical adhesive layer; judging whether bubbles exist in the optical adhesive layer; if bubbles exist, supplementing the optical adhesive layer with optical adhesive until the bubbles in the optical adhesive layer are discharged from the optical adhesive layer. The laminating method of the touch display device can solve the problem that bubbles are not easy to remove in the full-laminating process of the display module and the touch panel.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a bonding method of a touch display device. BACKGROUND

[0002] In the full bonding process of the display module and the touch panel, bubbles are prone to appear in the liquid adhesive layer between the display module and the touch panel, and the bubbles need to be removed in time to improve the product yield. However, the bubbles are currently removed by manual extrusion, which is inconvenient to operate, low in efficiency, and difficult to effectively remove the bubbles. SUMMARY

[0003] Therefore, it is necessary to provide a bonding method of a touch display device to solve the problem that bubbles are not easy to remove in the full bonding process of the display module and the touch panel.

[0004] According to an aspect of the present application, a bonding method of a touch display device is provided, which comprises the following steps: providing a display module and a touch panel; bonding the display module and the touch panel through an optical adhesive layer; judging whether there is a bubble in the optical adhesive layer; if there is a bubble, supplementing optical adhesive to the optical adhesive layer until the bubble in the optical adhesive layer is discharged from the optical adhesive layer.

[0005] In some embodiments, the supplementing of optical adhesive to the optical adhesive layer comprises: controlling the supplementing amount of optical adhesive according to the size of the bubble.

[0006] In some embodiments, the display module has a first surface for bonding with the touch panel, and the touch panel has a second surface for bonding with the display module; the bonding of the display module and the touch panel through the optical adhesive layer comprises: applying optical adhesive on the first surface or the second surface to form the optical adhesive layer; directing the first surface of the display module towards the second surface of the touch panel, and making the display module and the touch panel close to each other until the opposite two side surfaces of the optical adhesive layer are in contact with the first surface and the second surface respectively.

[0007] In some embodiments, the directing of the first surface of the display module towards the second surface of the touch panel and the making of the display module and the touch panel close to each other comprises: horizontally placing one of the display module and the touch panel, which is coated with optical adhesive, on a bearing surface, and making the other of the display module and the touch panel, which is not coated with optical adhesive, close to the bearing surface.

[0008] In some embodiments, the method further comprises: applying pressure to the other of the display module and the touch panel, which is not coated with optical adhesive, to make the optical adhesive in the optical adhesive layer uniformly dispersed.

[0009] In some embodiments, the supplementing the optical adhesive layer with optical adhesive comprises injecting optical adhesive into the gap between the display module and the touch panel using an injection tube.

[0010] In some embodiments, the injecting optical adhesive into the gap between the display module and the touch panel using an injection tube comprises obtaining a point on the edge line of the display module closest to the bubble in the optical adhesive layer, drawing a virtual connection line passing through the point and the center point of the bubble; and injecting optical adhesive into the gap between the display module and the touch panel along the virtual connection line from another intersection point of the virtual connection line and the edge line of the display module.

[0011] In some embodiments, the optical adhesive has a viscosity of 5400±500 mPa·s; and / or the optical adhesive has a light transmittance greater than or equal to 99%.

[0012] In some embodiments, the injection tube comprises a tube for storing optical adhesive and a needle head which is hollow inside and in communication with the tube; the needle head comprises an injection section and a connecting section connected between the injection section and the tube, and the connecting section is detachably connected to the injection tube.

[0013] In some embodiments, the connecting section has a hole diameter of 1 cm±0.1 cm; and / or the hole diameter of the injection section continuously decreases from one end close to the connecting section to one end away from the connecting section.

[0014] The method for bonding the touch display device provided by the embodiments of the present application can supplement the optical adhesive layer with optical adhesive after determining that there is a bubble in the optical adhesive layer between the display module and the touch panel, use the newly added optical adhesive to make the colloid in the optical adhesive layer flow, and drive the bubble in the optical adhesive layer to move until the bubble in the optical adhesive layer is discharged from the optical adhesive layer, thereby improving the convenience of operation, improving the work efficiency, and improving the success rate of removing the bubble. BRIEF DESCRIPTION OF DRAWINGS

[0015] Fig. 1 A flow chart of a method for bonding a touch display device in an embodiment of the present application is shown;

[0016] Fig. 2 A schematic diagram of a bonding process of a touch display device in an embodiment of the present application is shown;

[0017] Fig. 3 A schematic diagram of injecting optical adhesive into a gap between a display module and a touch panel in an embodiment of the present application is shown.

[0018] BRIEF DESCRIPTION OF DRAWINGS

[0019] 10: display module 40: bubble

[0020] 20: touch panel 50: virtual connection line

[0021] 30: optical adhesive layer 60: glue injection pipe DETAILED DESCRIPTION

[0022] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of different ways beyond the specific embodiments described and it is therefore contemplated to cover all such modifications as fall within the scope of the application. It is to be understood that the following description is exemplary only and is intended to provide a descriptive copy of the preferred embodiments disclosed herein, and is not intended to limit the scope of the present application in any way.

[0023] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0024] In addition, the terms "first", "second", "third" and the like are used only for descriptive purposes and are not intended to indicate or imply relative importance or a specific number of the technical features indicated. Therefore, the features defined with "first", "second" can include at least one of the features, explicitly or implicitly. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0025] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically defined. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0026] In the present application, unless specifically stated and limited otherwise, a first feature "on" or "under" a second feature can be directly in contact with the second feature, or indirectly in contact with the second feature through an intermediate medium. Also, a first feature "over", "above" and "on top of" a second feature can be directly above or diagonally above the second feature, or simply means that the first feature is horizontally higher than the second feature. A first feature "under", "below" and "underneath" a second feature can be directly below or diagonally below the second feature, or simply means that the first feature is horizontally lower than the second feature.

[0027] It should be noted that when an element is referred to as being "fixed" or "set" on another element, it can be directly on the other element or there can be an intermediate element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there can be an intermediate element. The terms "vertical", "horizontal", "up", "down", "left", "right", and the like used herein are for illustrative purposes only and are not intended to be the only implementation.

[0028] In the production process of the touch display device, a laminating process of the touch panel and the display module is involved. The laminating manner between the touch panel and the display module includes frame lamination and full lamination. The frame lamination is to laminate the outer edges of the touch panel and the display module together by using a glue frame, and the full lamination is to laminate the touch panel and the display module together as a whole. Since the full lamination has better light transmittance and color saturation than the frame lamination, the full lamination process is widely used in the production process of the touch display device.

[0029] However, in the full lamination process, if uneven coating or offset of the coating area occurs in the coating stage, or bubbles are carried in the liquid glue, bubbles are likely to occur in the liquid glue layer between the display module and the touch panel after the display module and the touch panel are laminated. When bubbles occur in the liquid glue layer between the display module and the touch panel, the bubbles need to be removed in time to improve the product yield.

[0030] In the conventional process, the bubbles are usually removed by manual extrusion. Specifically, first, the display module and the touch panel after being attached are extruded by fingers, so that the liquid glue between the display module and the touch panel flows under the pressure, the flowing liquid glue pushes away the bubbles and fills the positions originally occupied by the bubbles, until the bubbles escape from the edges of the display module and the touch panel; then, a point light source is used to continuously irradiate the position where the bubbles disappear, so that the liquid glue filled in the position solidifies. In the whole process, in order to prevent the bubbles from rebounding, the fingers need to continuously extrude the display module and the touch panel and cannot be loosened. Therefore, the manual extrusion method is inconvenient and inefficient. Moreover, it is difficult to accurately control the stress direction of the bubbles in the process of manual extrusion, and the bubbles may move in any direction in the process of extrusion. If the bubbles move towards the central area in the process of extrusion, the risk of unsuccessful removal of the bubbles is relatively large.

[0031] To solve the above problems, the application provides an attaching method of a touch display device, which extrudes the bubbles from the gap between the display module and the touch panel by injecting liquid glue into the gap between the display module and the touch panel and using the newly added liquid glue. Since the amount and speed of the injected glue can be flexibly controlled according to the position change of the bubbles in the process of glue injection, the movement direction of the bubbles can be adjusted by the flow of the newly added liquid glue, until the bubbles are extruded, so that the convenience of operation, the work efficiency and the success rate of removing the bubbles can be improved.

[0032] Fig. 1 A flow chart of the attaching method of the touch display device in an embodiment of the application is shown. Fig. 2 An attaching process diagram of the touch display device in an embodiment of the application is shown. Fig. 3 A state diagram of injecting optical glue into the gap between the display module and the touch panel in an embodiment of the application is shown.

[0033] Referring to Figs. 1 to 3 The attaching method of the touch display device provided by an embodiment of the application comprises the following steps:

[0034] Step S1, providing a display module 10 and a touch panel 20;

[0035] Step S2, attaching the display module 10 and the touch panel 20 by an optical glue layer 30;

[0036] Step S3, judging whether there are bubbles 40 in the optical glue layer 30;

[0037] Step S4, if there are bubbles 40, supplementing optical glue to the optical glue layer 30 until the bubbles 40 in the optical glue layer 30 are discharged from the optical glue layer 30.

[0038] The method for bonding the touch display device provided by the embodiments of the present application can, after judging that there is a bubble 40 in the optical adhesive layer 30 between the display module 10 and the touch panel 20, supplement optical adhesive into the optical adhesive layer 30, use the newly added optical adhesive to make the gel in the optical adhesive layer 30 flow and drive the bubble 40 in the optical adhesive layer 30 to move, until the bubble 40 in the optical adhesive layer 30 is discharged from the optical adhesive layer 30, thereby improving the convenience of operation, improving the work efficiency, and improving the success rate of removing the bubble 40.

[0039] After confirming that the bubble 40 in the optical adhesive layer 30 is discharged, the display module 10 and the touch panel 20 can be cleaned by using a dry and dust-free cloth first, and then a small amount of adhesive remover is used to clean the residual adhesive. After cleaning, the surface curing, angle curing and edge curing processes are performed in sequence.

[0040] Optionally, the way of judging whether there is a bubble 40 in the optical adhesive layer 30 can be observing by the human eye. Optionally, if it is judged that there is no bubble 40 in the optical adhesive layer 30, the optical adhesive in the optical adhesive layer 30 is directly cured.

[0041] In some embodiments, supplementing optical adhesive into the optical adhesive layer 30 includes: controlling the supplement amount of optical adhesive according to the size of the bubble 40. Specifically, the larger the volume of the bubble 40 or the larger the coverage area of the bubble 40, the larger the supplement amount of optical adhesive. In this way, the amount of optical adhesive can be saved while ensuring that the bubble 40 is successfully removed, thereby reducing costs and reducing the workload of subsequent residual adhesive cleaning.

[0042] In some embodiments, the display module 10 has a first surface for bonding with the touch panel 20, and the touch panel 20 has a second surface for bonding with the display module 10. Exemplarily, the first surface of the display module 10 is located at the display side of the display module 10, and the second surface of the touch panel 20 is located at the side away from the touch side of the touch panel 20. Bonding the display module 10 and the touch panel 20 through the optical adhesive layer 30 includes: applying optical adhesive on the first surface or the second surface to form the optical adhesive layer 30; directing the first surface of the display module 10 towards the second surface of the touch panel 20, and making the display module 10 and the touch panel 20 close to each other until the opposite two side surfaces of the optical adhesive layer 30 are in contact with the first surface and the second surface, respectively. In this way, under the restriction of the display module 10 and the touch panel 20, the optical adhesive in the optical adhesive layer 30 will diffuse in the gap between the display module 10 and the touch panel 20 to completely cover the first surface and the second surface, realizing full bonding between the display module 10 and the touch panel 20.

[0043] Further, the first surface of the display module 10 is directed towards the second surface of the touch panel 20, and the display module 10 and the touch panel 20 are brought close to each other, including: one of the display module 10 and the touch panel 20, which is coated with the optical adhesive, is horizontally placed on a bearing surface, and the other of the display module 10 and the touch panel 20, which is not coated with the optical adhesive, is brought close to the one. The bearing surface can be specifically the upper surface of a bearing platform. For example, the display module 10 and the touch panel 20 are bonded by the optical adhesive layer 30, including: the first surface is coated with the optical adhesive, and based on this, the first surface of the display module 10 is directed towards the second surface of the touch panel 20, and the display module 10 and the touch panel 20 are brought close to each other, including: the display module 10 is horizontally placed on the bearing surface, and the touch panel 20 is brought close to the display module 10 until the second surface of the touch panel 20 contacts the optical adhesive layer 30 coated on the display module 10. Since the display module 10 or the touch panel 20 coated with the optical adhesive is horizontally placed, the optical adhesive diffuses in the horizontal plane, so that the optical adhesive can be uniformly dispersed, so that the thickness of the optical adhesive layer 30 is relatively uniform.

[0044] Optionally, the bonding method of the touch display device further includes: applying pressure to the other of the display module 10 and the touch panel 20, which is not coated with the optical adhesive, to uniformly disperse the optical adhesive in the optical adhesive layer 30. When pressure is applied to the other of the display module 10 and the touch panel 20, which is not coated with the optical adhesive, the optical adhesive located between the display module 10 and the touch panel 20 is extruded, so that the optical adhesive in the part with a larger thickness of the optical adhesive layer 30 flows to the surrounding, so that the thickness of the optical adhesive layer 30 is uniform. After the optical adhesive flows and disperses and there is no obvious area between the display module 10 and the touch panel 20 that is not covered by the optical adhesive, the pressure can be stopped, and whether there is a bubble 40 is observed. If there is a bubble 40, the optical adhesive is supplemented to the optical adhesive layer 30 until the bubble 40 in the optical adhesive layer 30 is discharged from the optical adhesive layer 30.

[0045] In some embodiments, supplementing the optical adhesive to the optical adhesive layer 30 includes: injecting the optical adhesive into the gap between the display module 10 and the touch panel 20 by using an injection tube 60. By injecting the optical adhesive into the gap between the display module 10 and the touch panel 20 by using the injection tube 60, the direction of supplementing the optical adhesive can be accurately controlled, so that the bubble 40 is extruded in a directional manner, and the efficiency and success rate of removing the bubble 40 are improved.

[0046] Optionally, the injecting the optical glue into the gap between the display module 10 and the touch panel 20 by the glue injection tube 60 comprises: obtaining a point on the edge line of the display module 10 closest to the bubble 40 in the optical glue layer 30, drawing a virtual connection line 50 passing through the point and the center point of the bubble 40; injecting the optical glue into the gap between the display module 10 and the touch panel 20 from another intersection point of the virtual connection line 50 and the edge line of the display module 10 along the virtual connection line 50. In this way, the bubble 40 is pushed by the optical glue during the injection of the optical glue, and moves along the direction of the virtual connection line 50, so that the bubble 40 is pushed out of the optical glue layer 30 along the shortest path, thereby improving the efficiency of removing the bubble 40.

[0047] In some embodiments, the viscosity of the optical glue is 5400±500 mPa·s. In this way, before the optical glue between the display module 10 and the touch panel 20 is cured, the optical glue can stay in the area between the display module 10 and the touch panel 20 due to the viscosity of the optical glue, and can also flow as needed to ensure the uniformity of the optical glue layer 30 and effectively remove the bubble 40.

[0048] Optionally, the optical glue has a light transmittance greater than or equal to 99%. For example, for light with a wavelength λ=550 nm, the optical glue has a light transmittance greater than or equal to 99%. Optionally, the optical glue is a colorless transparent liquid or a light yellow transparent liquid. Based on this, the display module 10 and the touch panel 20 are bonded by using the optical glue, which can ensure good light output effect, thereby improving the display effect.

[0049] In some embodiments, the glue injection tube 60 comprises a glue tube for storing the optical glue and a needle head inside hollow and in communication with the glue tube; the needle head comprises a glue injection section and a connecting section connected between the glue injection section and the glue tube, and the connecting section is detachably connected with the glue injection tube 60. Based on this, when the glue tube or the needle head has problems such as blockage, contamination or damage, the glue tube and the needle head can be detached for partial replacement, avoiding the whole replacement, thereby reducing the cost.

[0050] Optionally, the glue tube is a transparent tube, which facilitates observation of the remaining amount of the optical glue in the glue tube, so as to supplement the optical glue in time when the remaining amount of the optical glue is insufficient.

[0051] Optionally, the connecting head is provided on the tube, and the connecting section is inserted into the connecting head and is in interference fit with the connecting head. In this way, the connection between the tube and the needle can have good sealing effect, and the disassembly and assembly of the tube and the needle can be facilitated. For example, the tube comprises a tube body and a connecting head connected to one end of the tube body, wherein the inner diameter of the connecting head is smaller than the inner diameter of the tube body. In this way, the tube can have a large storage capacity while ensuring good sealing connection between the tube and the needle. Therefore, the tube is filled with optical glue once, and the number of uses is large, thereby reducing the frequency of injecting optical glue into the tube, and improving the work efficiency.

[0052] Optionally, the needle is made of hard plastic. In this way, the needle can maintain a stable shape during the glue injection process, thereby ensuring that the injection direction of the optical glue is stable.

[0053] In some embodiments, the hole diameter of the connecting section is 1 cm ± 0.1 cm. For example, the cross section of the connecting section is circular. It can be understood that when the cross section of the connecting section is non-circular, the hole diameter of the connecting section of 1 cm ± 0.1 cm means that the equivalent hole diameter of the connecting section is 1 cm ± 0.1 cm. On the one hand, the hole diameter can allow the optical glue with a certain viscosity to pass smoothly, thereby reducing the probability that the optical glue blocks the connection between the tube and the needle. On the other hand, the needle with the hole diameter of this specification is common on the market, easy to purchase, and low in cost.

[0054] Optionally, the hole diameter of the glue injection section continuously decreases from the end close to the connecting section to the end away from the connecting section. It can be understood that when the cross section of the glue injection section is circular, the shape of the glue injection section is a circular truncated cone. When the end of the glue injection section away from the connecting section is infinitely reduced, the shape of the glue injection section is a circular cone. Based on this, the hole diameter of the needle decreases as the distance from the tube increases. In this way, the optical glue injected from the needle is more concentrated, so as to more accurately control the injection direction of the optical glue, thereby efficiently expelling the bubbles 40 out of the optical glue layer 30 in a predetermined direction. Moreover, since the hole diameter of the needle continuously decreases, that is, the inner wall of the needle is smooth without obvious corners, the flow of the optical glue in the needle is smoother, thereby reducing the probability that the needle is blocked.

[0055] In some embodiments, the glue injection tube 60 is connected with a pressure controller. In this way, the pressure applied to the glue injection tube 60 can be flexibly adjusted by the pressure controller, thereby flexibly adjusting the glue injection amount of the glue injection tube 60. Based on this, in combination with the hole diameter design of the needle, the glue injection speed of the glue injection tube 60 can be further adjusted.

[0056] Optionally, the pressure control circuit of the pressure controller is connected with a pressure control switch, and the pressure applied to the glue injection pipe 60 is controlled through the pressure control switch. For example, the pressure control switch includes a pedal, so that the operator can control the glue injection direction of the glue injection pipe 60 through hand action, and at the same time control the glue injection amount of the glue injection pipe 60 through leg action, thereby improving the operation convenience and flexibility.

[0057] Since the bonding method of the touch display device of the present application adopts the way of supplementing optical glue to expel the bubbles 40, it is not necessary for the operator to continuously press the display module 10 or the touch panel 20, and the bubbles 40 can be expelled at a lower temperature by controlling the supplement amount of the optical glue. Based on this, the bonding method can be applied to display modules 10 of different sizes.

[0058] According to the actual test application results, based on the bonding method of the touch display device of the present application, by supplementing an appropriate amount of glue and solidifying the newly injected optical glue, compared with the traditional manual extrusion method, the success rate of removing the bubbles 40 can be improved from 60% to 85%, thereby reducing the proportion of bubble 40 defects of the product, improving the full-bonding process yield, and reducing the production cost.

[0059] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not contradict, they should be considered within the scope of the present disclosure.

[0060] The above-described embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A method for bonding a touch display device, characterized in that, The method comprises the following steps: Providing a display module and a touch panel; Attaching the display module and the touch panel through an optical adhesive layer; Judging whether there is a bubble in the optical adhesive layer; If there is a bubble, supplementing optical adhesive to the optical adhesive layer until the bubble in the optical adhesive layer is discharged from the optical adhesive layer; The step of supplementing optical adhesive to the optical adhesive layer comprises: Obtaining a point on the edge line of the display module closest to the bubble in the optical adhesive layer, and drawing a virtual connection line passing through the point and the center point of the bubble; 2. The method of claim 1, wherein the method further comprises: From the other intersection point of the virtual connection line and the edge line of the display module, injecting optical adhesive into the gap between the display module and the touch panel along the virtual connection line by using an injection tube. The step of supplementing optical adhesive to the optical adhesive layer comprises:

3. The method of Claim 1, wherein Controlling the supplement amount of optical adhesive according to the size of the bubble. The display module has a first surface for attaching the touch panel, and the touch panel has a second surface for attaching the display module; The step of attaching the display module and the touch panel through an optical adhesive layer comprises: Coating optical adhesive on the first surface or the second surface to form an optical adhesive layer; 4. The method of Claim 3, wherein Facing the first surface of the display module towards the second surface of the touch panel, and making the display module and the touch panel close to each other until the opposite side surfaces of the optical adhesive layer are in contact with the first surface and the second surface, respectively. The step of facing the first surface of the display module towards the second surface of the touch panel, and making the display module and the touch panel close to each other comprises:

5. The method of Claim 4, wherein Horizontally placing the one of the display module and the touch panel coated with optical adhesive on a bearing surface, and making the other one of the display module and the touch panel not coated with optical adhesive close to the bearing surface. The method further comprises:

6. The method of Claim 1, wherein Applying pressure to the other one of the display module and the touch panel not coated with optical adhesive to make the optical adhesive in the optical adhesive layer uniformly dispersed. The viscosity of the optical adhesive is 5400±500 mPa·s; and / or 7. The method of Claim 1, wherein The optical transmittance of the optical adhesive is greater than or equal to 99%. The injection tube comprises a glue tube for storing optical adhesive and a needle head inside hollow and in communication with the glue tube; 8. The method according to claim 7, wherein The needle head comprises an injection section and a connecting section connected between the injection section and the glue tube, and the connecting section is detachably connected with the injection tube. The hole diameter of the connecting section is 1 cm±0.1 cm; and / or The hole diameter of the injection section continuously decreases from one end close to the connecting section to the other end away from the connecting section.

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