CN115584219B

CN115584219B - Bonding structure, preparation method thereof and foldable display module

Info

Publication number: CN115584219B
Application number: CN202211251746.0A
Authority: CN
Inventors: 彭兆基; 肖一鸣; 姚鹏程; 甘帅燕; 王明晖
Original assignee: Kunshan Govisionox Optoelectronics Co Ltd
Current assignee: Kunshan Govisionox Optoelectronics Co Ltd
Priority date: 2022-10-13
Filing date: 2022-10-13
Publication date: 2024-01-30
Anticipated expiration: 2042-10-13
Also published as: CN115584219A

Abstract

The application discloses a bonding structure, a preparation method thereof and a foldable display module. The bonding structure comprises at least one first area and a second area connected with the first area, the second area comprises a first subarea and a second subarea, and the first subarea is connected between the first area and the second subarea; the bond structure has a hardness in the first subregion that is greater than its hardness in the second subregion, and the bond structure has a hardness in the first subregion that is less than its hardness in the first region. According to the embodiment of the application, the reliability of the bendable product is improved.

Description

Bonding structure, preparation method thereof and foldable display module

Technical Field

The application relates to the technical field of display, in particular to a bonding structure, a preparation method thereof and a foldable display module.

Background

In recent years, with the development of electronic technology and semiconductor technology, there has been an increasing demand for miniaturization and visualization of electronic devices such as mobile phones, media players, game machines, digital cameras, etc., that is, users want the storage volume of the electronic devices to be as small as possible for portability on the one hand, and on the other hand, the visualization effect of the electronic devices, for example, the area of the display screen is not reduced by the reduction of the storage volume of the electronic devices.

Therefore, there is a need to realize a foldable display device to reduce the volume after ensuring folding and storage of electronic equipment and to ensure excellent visual effects after extension, such as a large-area display screen. Accordingly, electronic devices having a folding display screen are receiving a great deal of attention. The folding screen can be unfolded when in use to provide a larger display area, and can be switched to a folding state when not in use, so that the folding screen is convenient for a user to carry, and the portability of the display device is improved.

The foldable product may comprise a plurality of film layers, and two adjacent film layers may be bonded using a bonding structure. Because the foldable product needs to be continuously bent in the use process, reliability risks are brought in the use process.

Disclosure of Invention

The embodiment of the application provides a bonding structure, a preparation method thereof and a foldable display module, which are beneficial to improving the reliability of bendable products.

In a first aspect, embodiments of the present application provide a bonding structure, including at least a first region and a second region connected to the first region, the second region including a first sub-region and a second sub-region, the first sub-region being connected between the first region and the second sub-region;

The bond structure has a hardness in the first subregion that is greater than its hardness in the second subregion, and the bond structure has a hardness in the first subregion that is less than its hardness in the first region.

In a possible implementation manner of the first aspect, the hardness of the bonding structure in the first sub-region gradually increases in a direction approaching the first region from the boundary between the first sub-region and the second sub-region;

optionally, in a direction approaching the first region from the boundary between the first and second subregions, the manner in which the hardness of the adhesive structure in the first subregion gradually increases includes at least one of: linear increase, curve increase, stepwise increase;

optionally, the bonding structure has the same hardness at each position of the second subregion;

optionally, the concentration of the curing agent of the bonding structure in the first subarea is greater than the concentration of the curing agent of the bonding structure in the second subarea, and the concentration of the curing agent of the bonding structure in the first subarea is less than the concentration of the curing agent of the bonding structure in the first subarea;

optionally, the concentration of the curing agent of the bonding structure in the first subarea is gradually increased in the direction of approaching the first area from the junction of the first subarea and the second subarea;

optionally, in a direction approaching the first region from the boundary between the first and second subregions, the manner in which the concentration of the curing agent of the adhesive structure in the first subregion gradually increases includes at least one of: linear increase, curve increase, stepwise increase;

Optionally, the curing agent concentration of the bonding structure at each position of the second subregion is the same;

optionally, the bonding structure comprises an optical cement and the curing agent comprises a photosensitizer.

In a possible embodiment of the first aspect, the adhesive structure has the same hardness at each location of the first area;

or in the direction from the first area to the second area, the hardness of the bonding structure in the first area is gradually increased and then gradually decreased;

optionally, the hardness of the bonding structure in the first region gradually decreases from the center of the first region to a direction approaching the second region;

optionally, the manner in which the stiffness of the adhesive structure in the first region gradually decreases from the center of the first region toward the direction approaching the second region includes at least one of: linear decrease, curve decrease, stepwise decrease;

optionally, the curing agent concentration of the bonding structure at each location of the first region is the same;

or in the direction from the first area to the second area, the concentration of the curing agent in the first area of the bonding structure is gradually increased and then gradually decreased;

optionally, the concentration of the curing agent in the first region of the bonding structure gradually decreases from the center of the first region to a direction approaching the second region;

Optionally, the manner in which the concentration of the curing agent in the first region of the adhesive structure gradually decreases from the center of the first region toward the direction approaching the second region includes at least one of: linear decrease, curve decrease, stepwise decrease;

optionally, the bonding structure comprises an optical cement and the curing agent comprises a photosensitizer;

optionally, the body of the adhesive structure in the first region and the body thereof in the second region are of unitary construction.

Based on the same inventive concept, in a second aspect, an embodiment of the present application provides a bonding structure, including at least a first region and a second region connected with the first region, wherein the second region includes a first sub-region and a second sub-region, and the first sub-region is connected between the first region and the second sub-region;

the adhesive structure has a greater concentration of curing agent in the first subregion than in the second subregion, and the adhesive structure has a lesser concentration of curing agent in the first subregion than in the first region.

Based on the same inventive concept, in a third aspect, an embodiment of the present application provides a method for preparing a bonding structure, including:

providing a bonding body layer, wherein the bonding body layer comprises at least one first area and a second area connected with the first area, the second area comprises a first subarea and a second subarea, and the first subarea is connected between the first area and the second subarea;

And (3) processing the bonding body layer by using a preset curing process to obtain a bonding structure, wherein the hardness of the bonding structure in the first subarea is higher than that of the bonding structure in the second subarea, and the hardness of the bonding structure in the first subarea is lower than that of the bonding structure in the first area.

In one possible embodiment of the third aspect, treating the bond body layer with a preset curing process comprises:

the method comprises the steps of irradiating the bonding body layer by a preset light source, enabling the light quantity received by a first subarea in a unit area to be larger than the light quantity received by a second subarea in the unit area, and enabling the light quantity received by the first subarea in the unit area to be smaller than the light quantity received by the first area in the unit area, wherein the hardening degree of the bonding body layer irradiated by the preset light source is positively correlated with the light quantity received by the bonding body layer.

In a possible implementation manner of the third aspect, the illuminating the bonding body layer with the preset light source, so that the amount of light received by the first sub-region in the unit area is greater than the amount of light received by the second sub-region in the unit area, and the amount of light received by the first sub-region in the unit area is less than the amount of light received by the first region in the unit area, includes:

uniformly irradiating the bonding body layer by using a first preset light source;

The second preset light source is arranged in the shielding cover and irradiates the bonding body layer, the shielding cover comprises an opening, and orthographic projection of the opening on the bonding body layer at least surrounds the first area and the first subarea;

optionally, the inner wall of the shielding cover can reflect the light emitted by the second preset light source;

optionally, the shield is generally cylindrical.

a photomask is arranged between a preset light source and the bonding body layer, the photomask comprises a first light transmission area and a second light transmission area connected with the first light transmission area, the second light transmission area comprises a first sub light transmission area and a second sub light transmission area, the first sub light transmission area is connected between the first light transmission area and the second sub light transmission area, the transmittance of the first sub light transmission area is smaller than that of the first light transmission area and larger than that of the second sub light transmission area, the orthographic projection edge of the first light transmission area on the bonding body layer coincides with the edge of the first area, and the orthographic projection edge of the second light transmission area on the bonding body layer coincides with the edge of the second area;

Uniformly irradiating the photomask by using a preset light source;

optionally, the transmittance of each position of the first light-transmitting area is the same, or the transmittance of the first light-transmitting area gradually decreases from the center of the first light-transmitting area to the direction approaching the second light-transmitting area;

optionally, the transmittance of the first sub-light-transmitting area gradually increases in a direction from the first sub-light-transmitting area and the second sub-light-transmitting area to the first light-transmitting area;

optionally, the transmittance of each position of the second sub-light-transmitting area is the same.

In one possible implementation manner of the third aspect, the concentration of the curing agent in the first subarea of the adhesive body layer is greater than the concentration of the curing agent in the second subarea of the adhesive body layer, and the concentration of the curing agent in the first subarea of the optical cement adhesive structure is smaller than the concentration of the curing agent in the first subarea of the optical cement adhesive structure, wherein the concentration of the curing agent in the adhesive body layer is positively correlated with the hardening degree of the adhesive body layer after the adhesive body layer is treated by a preset curing process;

treating the bonded body layer with a preset curing process comprising:

uniformly irradiating the bonding body layer by using a preset light source;

optionally, the concentration of the curing agent in the first sub-region gradually increases in a direction from the junction of the first sub-region and the second sub-region to the first region;

Optionally, the concentration of the curing agent at each position of the second subregion is the same;

optionally, the concentration of the curing agent at each position of the first area is the same, or the concentration of the curing agent in the first area is gradually increased and then gradually decreased from the center of the first area to the direction of approaching the second area;

optionally, the concentration of the curing agent in the first region gradually decreases from the center of the first region toward the direction approaching the second region;

Based on the same inventive concept, in a fourth aspect, an embodiment of the present application provides a foldable display module, including a bendable region and a non-bendable region connected to the bendable region, the foldable display module further includes:

a plurality of functional layers; and

a bonding structure according to any one of the first aspects disposed between two adjacent functional layers;

the first region corresponds to the position of the bendable region, the second region corresponds to the position of the non-bendable region, and the first region corresponds to the position of at least one of the bendable region and the non-bendable region;

optionally, the foldable display module assembly further includes a uv-protective layer, the plurality of functional layers includes a display panel and a cover plate, the bonding structure is located between the display panel and the cover plate, and the uv-protective layer is located at a side of the cover plate away from the bonding structure.

According to the bonding structure, the preparation method thereof and the foldable display module provided by the embodiment of the application, on one hand, the hardness of the bonding structure in the first area is larger, the hardness of the bonding structure in the second area is smaller, therefore, the bonding structure is not easy to deform in the first area, the bonding structure is easy to deform in the second area, the first area corresponds to the bendable area of the foldable display module, at least part of the second area corresponds to the non-bending area of the foldable display module, and therefore in the bending process of the foldable display module, the deformation capacity of the bonding structure can be matched with the change trend that the relative slippage amount generated between different film layers is larger along with the increase of the distance from a rotating shaft, and thus the softer and more easily deformed second area of the bonding structure can be matched with the non-bending area with the larger slippage amount, so that the stress between adjacent film layers is controlled to be at a lower level, and the reliability of the folding display module in the bending process is improved. On the other hand, the second area comprises a first subarea and a second subarea, the first subarea is connected between the first area and the second subarea, and the hardness of the first subarea is between the hardness of the first area and the hardness of the second subarea, so that the stress at the junction of the bendable area and the non-bendable area of the foldable display module can be balanced. That is, the hardness of each region is gradually changed in the arrangement direction of each region, so that the stress distribution generated in the bending process is more uniform.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading the following detailed description of non-limiting embodiments, taken in conjunction with the accompanying drawings, in which like or similar reference characters designate the same or similar features, and which are not to scale.

Fig. 1 shows a schematic structural diagram of a bendable display module in a bent state;

FIG. 2 is a schematic view of an adhesive structure according to an embodiment of the present application in an unfolded state;

FIG. 3 illustrates a schematic diagram of a distribution of bond structure stiffness provided by embodiments of the present application;

FIG. 4 is a schematic view of another construction of an adhesive construction according to an embodiment of the present application in an unfolded state;

FIG. 5 illustrates another distribution diagram of bond structure stiffness provided by embodiments of the present application;

fig. 6 shows yet another distribution of bond structure stiffness provided by embodiments of the present application.

Fig. 7 is a schematic flow chart of a method for preparing a bonding structure according to an embodiment of the present disclosure;

FIG. 8 is a schematic view of a bonding structure according to an embodiment of the present disclosure;

FIGS. 9 a-9 b are schematic views of other structures during the preparation of the bonded structure provided in embodiments of the present application;

FIG. 10 is a schematic view of a bonding structure according to an embodiment of the present disclosure;

FIGS. 11a and 11b are schematic diagrams showing transmittance distribution of a photomask during the preparation of a bonding structure according to embodiments of the present application;

FIG. 12 is a schematic view of a further construction of a bonded structure according to an embodiment of the present application;

FIGS. 13a and 13b are schematic diagrams showing the distribution of the concentration of the curing agent during the preparation of the bonded structure according to the examples provided herein;

fig. 14 is a schematic structural diagram of a foldable display module according to an embodiment of the present application.

Fig. 15 is a schematic structural diagram of a foldable display module according to an embodiment of the present application.

Detailed Description

Features and exemplary embodiments of various aspects of the present application are described in detail below to make the objects, technical solutions and advantages of the present application more apparent, and to further describe the present application in conjunction with the accompanying drawings and the detailed embodiments. It should be understood that the specific embodiments described herein are merely configured to explain the present application and are not configured to limit the present application. It will be apparent to one skilled in the art that the present application may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present application by showing examples of the present application.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.

It will be understood that when a layer, an area, or a structure is described as being "on" or "over" another layer, another area, it can be referred to as being directly on the other layer, another area, or another layer or area can be included between the layer and the other layer, another area. And if the component is turned over, that layer, one region, will be "under" or "beneath" the other layer, another region.

It should be understood that the term "and/or" as used herein is merely one relationship describing the association of the associated objects, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In the embodiments of the present application, the term "connected" may refer to two components being directly connected, or may refer to two components being connected via one or more other components.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present application without departing from the spirit or scope of the application. Accordingly, this application is intended to cover such modifications and variations of this application as fall within the scope of the appended claims (the claims) and their equivalents. The embodiments provided in the examples of the present application may be combined with each other without contradiction.

Before describing the technical solution provided by the embodiments of the present application, in order to facilitate understanding of the embodiments of the present application, the present application first specifically describes the problems existing in the related art:

With the development of flexible display technology, flexible display screens have been applied to foldable display modules provided with a folding structure.

As shown in fig. 1, an adhesive structure 20' may be disposed between adjacent functional layers 10 and 30 in the foldable display module. The foldable display module may include a bendable region 104 and a non-bendable region 102, and the hinge 41 may be disposed on the bendable region 104. The inventor researches that during the bending process of the folding display module, relative sliding displacement can be generated between different film layers. Specifically, in the directions D1 and D2, the larger the relative slip amount generated between the different film layers with an increase in distance from the rotation axis. If the properties of the bond structure 20' are consistent at various locations, uneven stress may result in the pliable region 104 and the non-pliable region 102, with a reliability risk.

In order to solve the problems, the application provides a bonding structure, a preparation method thereof and a foldable display module, which are beneficial to improving the reliability of the foldable display module.

The following first describes the bonding structure provided in the embodiments of the present application.

Fig. 2 is a schematic structural view of an adhesive structure according to an embodiment of the present application in an unfolded state. As shown in fig. 2, the adhesive structure 20 may include at least one first region 21 and a second region 22 connected with the first region 21. The bonding structure 20 may be used to bond adjacent functional layers in the foldable display module, for example, the functional layers of the foldable display module may include a cover plate and a display panel, and the bonding structure 20 may be located between the cover plate and the display panel to bond the cover plate and the display panel.

The foldable display module may include a bendable region and a non-bendable region, the first region 21 may correspond to a position of the bendable region of the foldable display module, and the second region 22 may correspond to a position of the non-bendable region of the foldable display module. Optionally, the first region 21 is a bendable region. Optionally, the second region 22 is a non-bending region, or a portion of the second region 22 away from the first region 21 is a non-bending region, and a portion of the second region 22 close to the first region 21 is a bendable region. The second region 22 may be plural. Opposite sides of the first region 21 may be provided with second regions 22. When not bent, i.e., when flattened, the first regions 21 and the second regions 22 may be alternately arranged along the first direction.

It should be noted that, the number of the first areas 21 is determined by the number of folds of the foldable display module, if the foldable display module is folded once (i.e. single folded), the bonding structure 20 may include one first area 21, and if the foldable display module is folded twice (i.e. double folded), the bonding structure 20 may include two first areas 21.

Fig. 3 shows a schematic diagram of the distribution of the hardness of the bonded structure provided in the embodiment of the present application. Wherein hardness may refer to a physical quantity of the component's ability to resist deformation. The greater the stiffness of the bonded structure, the greater the resistance to deformation, and the less likely it is to deform. The lower the stiffness of the bonded structure, the weaker the resistance to deformation and the easier the deformation.

As shown in fig. 3, the bond structure 20 has a hardness in the first region 21 that is greater than its hardness in the second region 22.

Because the hardness of the bonding structure 20 in the first area 21 is larger, and the hardness of the bonding structure 20 in the second area 22 is smaller, the bonding structure 20 is not easy to deform in the first area 21, the bonding structure 20 is easy to deform in the second area 22, the first area 21 corresponds to a bendable area of the foldable display module, and the second area 22 corresponds to a non-bendable area of the foldable display module, so that in the bending process of the foldable display module, the deformability of the bonding structure 20 can be matched with the change trend that the relative sliding amount generated between different film layers is larger along with the increase of the distance from a rotating shaft, and thus the second area 22 of the softer and more easily deformed bonding structure 20 can be matched with the non-bendable area with the larger sliding amount so as to control the stress between adjacent film layers to be at a lower level, thereby being beneficial to improving the reliability of the bending process of the foldable display module.

The adhesive construction 20 may include pressure sensitive adhesive, optical adhesive, and the like. Illustratively, the bonding structure 20 may include an optical adhesive, which may include OCA (Optical Clear Adhesive) or OCR (Optical Clear Resin), for example. Of course, the adhesive structure 20 may also include other optical cement materials.

Illustratively, the body of the bonded structure 20 in the first region 21 and its body in the second region 22 may be a unitary structure. For example, the body of the adhesive structure 20 in the first region 21 and its body in the second region 22 may be integrally formed. It will be appreciated that the first region 21 and the second region 22 may not be demarcated in terms of physical structure, with the difference being the hardness of the first region 21 and the second region 22. Since the bonding structure 20 is formed by integrating the first region 21 and the second region 22, breakage is not easily generated between the first region 21 and the second region 22 during bending, and reliability can be further improved.

It will be appreciated that the hardness of the first region 21 is relatively greater than the hardness of the second region 22, and that the hardness of the first region 21 is not infinite. The adhesive structure 20 may be folded in the first region 21.

The greater the stiffness of the bonded structure 20, the greater the modulus of elasticity thereof will be understood.

As one example, the range of elastic modulus of the bonded structure 20 in the first region 21 may include 80Kpa to 150Kpa. The elastic modulus of the bonded structure 20 in the second region 22 may range from 20Kpa to 80Kpa. These ranges are merely examples and are not intended to limit the present application.

The inventor also found that the foldable display module is easy to generate uneven stress at the junction of the bendable region and the non-bendable region in the bending process. In order to balance the stress at the interface of the pliable and non-pliable regions, a gradual transition in the hardness profile may be provided.

As an example, fig. 4 shows another schematic structural view of an adhesive structure provided in an embodiment of the present application in an unfolded state. Fig. 5 shows another distribution diagram of bond structure stiffness provided by embodiments of the present application. Fig. 6 shows yet another distribution of bond structure stiffness provided by embodiments of the present application. As shown in fig. 4 to 6, the second region 22 includes a first sub-region 221 and a second sub-region 222, the first sub-region 221 being connected between the first region 21 and the second sub-region 222. Optionally, the first region 21 is a bendable region. Optionally, the second sub-region 212 is a non-inflection region. Optionally, the first sub-area 221 is a non-bending area, or a portion of the first sub-area 221 away from the first area 21 is a non-bending area, and a portion of the first sub-area 221 close to the first area 21 is a bendable area.

The bond structure 20 has a hardness in the first subregion 221 that is greater than its hardness in the second subregion 222, and the bond structure 20 has a hardness in the first subregion 221 that is less than its hardness in the first region 21. Since the hardness of the first sub-area 221 is between the hardness of the first area 21 and the hardness of the second sub-area 222, the stress at the junction of the bendable area and the non-bendable area of the foldable display module can be balanced. That is, the hardness of each region is gradually changed in the arrangement direction of each region, so that the stress distribution generated in the bending process is more uniform. The stiffness of the bonding structure 20 is higher in the pliable region than in the non-pliable region, and the non-pliable region is more prone to deformation, matching the trend of the amount of relative displacement (slippage) between adjacent film layers on both sides of the bonding structure 20 during the process of folding the screen from the unfolded state to the pliable state.

Illustratively, the bond structure 20 gradually increases in stiffness in the first sub-region 221 in a direction proximate the first region 21 by the intersection of the first sub-region 221 and the second sub-region 222. For example, the manner in which the stiffness of the bond structure 20 increases gradually in the first subregion 221 includes at least one of: linear increase, curve increase, stepwise increase.

The above-described manner of increasing may make the transition of hardness from the first region 21 to the second region 222 smoother, and the first region 221 may correspond to a stress buffer zone, which may further improve reliability.

Illustratively, the bond structure 20 may be a unitary structure with the body of the first region 21, the body of the first sub-region 221, and the body of the second sub-region 222. For example, the body of the bond structure 20 at the first region 21, the body at the first sub-region 221, and the body at the second sub-region 222 may be integrally formed. It is understood that the first region 21, the first sub-region 221, and the second sub-region 222 may not be demarcated in terms of physical structure, with the difference in hardness of the first region 21, the first sub-region 221, and the second sub-region 222. Because the bonding structure 20 is formed by integrating the first area 21, the first sub-area 221 and the second sub-area 222, in the bending process, the first area 21, the first sub-area 221 and the second sub-area 222 are not easy to break, and the reliability can be further improved.

For example, as shown in fig. 5, the stiffness of the bond structure 20 may be the same at each location of the second subregion 222. The stiffness of the adhesive structure 20 may also be the same at each location of the first region 21.

As shown in fig. 5, the minimum value of the hardness of the first sub-region 221 may be the same as the hardness of the second sub-region 222, and the maximum value of the hardness of the first sub-region 221 may be the same as the hardness of the first region 21.

As another example, as shown in fig. 6, the first region may also be configured to have a graded transition hardness profile in order to balance the stresses at the interface of the pliable region and the non-pliable region. Alternatively, the stiffness of the bond structure 20 in the first region 21 increases gradually and then decreases gradually in a direction from the first region 21 to the second region 22. Specifically, the hardness of the adhesive structure 20 in the first region 21 may gradually decrease from the center of the first region 21 toward the direction approaching the second region 22. For example, the hardness of the adhesive structure 20 in the first region 21 may gradually decrease from the center of the first region 21 toward the direction approaching the second region 22, including at least one of the following: linear decrease, curve decrease, stepwise decrease. The stiffness of the adhesive structure 20 may be greatest in the center of the first region 21.

As shown in fig. 6, the minimum value of the hardness of the first sub-region 221 may be the same as the hardness of the second sub-region 222, and the maximum value of the hardness of the first sub-region 221 may be the same as the minimum value of the hardness of the first region 21.

In the case where the hardness of both the first sub-region 221 and the first region 22 gradually changes, the manner of change in the hardness of the first sub-region 221 may be the same as the manner of change in the hardness of the first region 21 from the center to both sides in the same direction. For example, the hardness of the first sub-region 221 changes linearly from one side to the other side and the hardness of the first region 22 changes linearly from the center to both sides, or changes in a curve, or changes in a stepwise manner, or the like.

For example, different concentrations of curing agent may be provided in different regions of the bonded structure 20 during the process of preparing the bonded structure, thereby achieving different hardness in the different regions.

Optionally, the concentration of the curing agent of the adhesive structure 20 in the first sub-area 221 is greater than the concentration of the curing agent of the adhesive structure 20 in the second sub-area 222, and the concentration of the curing agent of the adhesive structure 20 in the first sub-area 221 is less than the concentration of the curing agent of the adhesive structure in the first area 21. The curing agent herein may include a cured product after curing.

Alternatively, the concentration of the curing agent in the first sub-region 221 of the adhesive structure 20 gradually increases in a direction approaching the first region 21 from the boundary of the first sub-region 221 and the second sub-region 222.

Optionally, in a direction approaching the first region 21 from the boundary between the first sub-region 221 and the second sub-region 222, the manner in which the concentration of the curing agent of the adhesive structure 20 in the first sub-region 221 gradually increases includes at least one of: linear increase, curve increase, stepwise increase.

Optionally, the concentration of the curing agent is the same at each location of the second subregion 222 of the bond structure 20.

Alternatively, the concentration of the curing agent in the adhesive structure 20 is the same at each location of the first region 21, or the concentration of the curing agent in the adhesive structure 20 in the first region 21 is gradually increased and then gradually decreased in the direction from the first region 21 to the second region 22.

Alternatively, the concentration of the curing agent in the first region 21 of the adhesive structure 20 gradually decreases from the center of the first region 21 toward the second region 22. The concentration of the curing agent of the bonded structure 20 may be greatest in the center of the first region 21.

Optionally, the manner in which the concentration of the curing agent of the adhesive structure 20 in the first region 21 gradually decreases from the center of the first region 21 toward the direction approaching the second region 22 includes at least one of: linear decrease, curve decrease, stepwise decrease.

Optionally, the bonding structure 20 comprises an optical adhesive. Optionally, the curing agent comprises a photosensitizer.

By arranging different curing agent concentrations in different areas of the bonding structure 20, the influence of ultraviolet rays and the like in ambient light on the hardness of the bonding structure 20 can be avoided, and the ultraviolet rays in the ambient light are relatively uniformly irradiated to the bonding structure 20, so that the hardness of the different areas of the bonding structure 20 is related to the curing agent concentrations, the hardness change rule is ensured to meet the requirement, and the hardness change does not greatly change along with the use duration.

Based on the same inventive concept, the embodiments of the present application also provide a bonding structure. As shown in fig. 4, the adhesive structure 20 may include at least one first region 21 and a second region 22 connected with the first region 21. The second region 22 includes a first sub-region 221 and a second sub-region 222, the first sub-region 221 being connected between the first region 21 and the second sub-region 222. The concentration of the curing agent of the adhesive structure 20 in the first sub-area 221 is greater than the concentration of the curing agent of the adhesive structure 20 in the second sub-area 222, and the concentration of the curing agent of the adhesive structure 20 in the first sub-area 221 is less than the concentration of the curing agent of the adhesive structure in the first area 21. The curing agent herein is understood to be a curing agent which has not been subjected to a curing treatment.

In the embodiment of the present application, the hardness of the adhesive structure 20 may be the same in the first region 21, the first sub-region 221, and the second sub-region 222. For example, after the adhesive structure 20 is adhered to the functional film layer, the adhesive structure 20 may be subjected to a curing treatment, and the greater the concentration of the curing agent, the greater the hardness after the curing treatment, and thus the hardness of the adhesive structure 20 after the curing treatment may be different in each region, due to the difference in the concentration of the curing agent in each region.

Optionally, before or after the adhesive structure 20 is cured, the concentration of the curing agent of the adhesive structure 20 in the first sub-area 221 is greater than the concentration of the curing agent of the adhesive structure 20 in the second sub-area 222, and the concentration of the curing agent of the adhesive structure 20 in the first sub-area 221 is less than the concentration of the curing agent of the adhesive structure in the first area 21.

Optionally, before or after the adhesive structure 20 is cured, the concentration of the curing agent in the first sub-region 221 of the adhesive structure 20 gradually increases in a direction from the boundary between the first sub-region 221 and the second sub-region 222 to the first region 21.

Optionally, before or after the adhesive structure 20 is cured, in a direction approaching the first region 21 from the boundary between the first sub-region 221 and the second sub-region 222, the manner in which the concentration of the curing agent of the adhesive structure 20 in the first sub-region 221 gradually increases includes at least one of the following: linear increase, curve increase, stepwise increase.

Optionally, the concentration of the curing agent is the same at each location of the second subregion 222 of the adhesive structure 20 either before or after the adhesive structure 20 has been cured.

Optionally, before or after the adhesive structure 20 is cured, the concentration of the curing agent in each position of the first area 21 of the adhesive structure 20 is the same, or the concentration of the curing agent in the first area 21 of the adhesive structure 20 is gradually increased and then gradually decreased in a direction from the first area 21 to the second area 22.

Optionally, the concentration of the curing agent in the first region 21 of the adhesive structure 20 gradually decreases from the center of the first region 21 toward the second region 22 before or after the curing treatment of the adhesive structure 20.

Optionally, before or after the adhesive structure 20 is cured, the manner in which the concentration of the curing agent in the adhesive structure 20 in the first region 21 gradually decreases from the center of the first region 21 toward the second region 22 includes at least one of: linear decrease, curve decrease, stepwise decrease.

Based on the same inventive concept, the embodiment of the application also provides a preparation method of the bonding structure. As shown in fig. 7, the method for preparing the bonding structure provided in the embodiment of the present application includes S710 to S720.

S710, providing a bonding body layer, wherein the bonding body layer comprises at least one first area and a second area connected with the first area;

s720, treating the bonding body layer by a preset curing process to obtain the bonding structure, wherein the hardness of the bonding structure in the first area is higher than that of the bonding structure in the second area.

The specific implementation of S710 to S720 will be described in detail below.

According to the preparation method of the bonding structure, as the hardness of the bonding structure in the first area is larger, and the hardness of the bonding structure in the second area is smaller, the bonding structure is not easy to deform in the first area, the bonding structure is easy to deform in the second area, the first area corresponds to the bendable area of the foldable display module, the second area corresponds to the non-bending area of the foldable display module, and accordingly in the bending process of the foldable display module, the deformability of the bonding structure can be matched with the change trend that the relative slippage amount generated between different film layers is larger along with the increase of the distance from the rotating shaft, so that the second area of the bonding structure which is softer and more easy to deform can be matched with the non-bending area with the larger slippage amount, so that the stress between adjacent film layers is controlled to be at a lower level, and the reliability in the bending process of the foldable display module is improved.

S710 is first described. The preset curing process treatment may include photo curing, thermal curing, pressure curing, etc. The adhesive construction 20 may include pressure sensitive adhesive, optical adhesive, and the like.

The bonding structure can bond adjacent functional layers in the foldable display module. As an example, as shown in fig. 8, the adhesive body layer 201 provided in S710 may be located between the first functional layer 11 and the second functional layer 12 of the foldable display module, and S720 is performed again in a case where the adhesive body layer 201 is located between the functional layers. In the drawings, the case that the bonding body layer 201 is located between the functional layers is taken as an example, and this is not intended to limit the application, for example, the bonding body layer 201 may not be located between the functional layers during irradiation. Illustratively, the bond body layer may include an optical adhesive. The preset light source may emit Ultraviolet Rays (UV).

For example, the first region of the adhesive body layer may correspond to a position of a bendable region of the foldable display module, and the second region of the adhesive body layer may correspond to a position of a non-bendable region of the foldable display module.

The hardness of the adhesive body layer may be the same at each location before the adhesive body layer is irradiated with the preset light source.

Next, S720 is introduced. The bonding body layer is treated by a predetermined curing process, for example, the bonding body layer may be irradiated with a predetermined light source, which may be understood as curing the bonding body layer.

In some alternative embodiments, the treating the bonding body layer with the preset curing process in S720 may specifically include: the bonding body layer is irradiated by a preset light source, so that the light quantity received by the first area in unit area is larger than the light quantity received by the second area in unit area, and the hardening degree of the bonding body layer after being irradiated by the preset light source is positively related to the light quantity received by the bonding body layer.

The hardening degree of the bonding body layer after being irradiated by the preset light source is positively correlated with the received light quantity, the received light quantity of the first area in unit area is larger than the received light quantity of the second area in unit area, the hardening degree of the first area is ensured to be larger than that of the second area, and therefore the hardness of the obtained bonding structure in the first area is ensured to be larger than that of the bonding structure in the second area. At this time, the concentration of the curing agent in each region in the bond body layer may be the same. The light intensity of the preset light source is far greater than that of ultraviolet light in a conventional external environment.

In some alternative embodiments, irradiating the bonding body layer with a predetermined light source such that the first region receives a greater amount of light per unit area than the second region, may include: uniformly irradiating the bonding body layer by using a first preset light source; the second preset light source is arranged in the shielding cover and irradiates the bonding body layer, the shielding cover comprises an opening, and orthographic projection of the opening on the bonding body layer at least surrounds the first area.

As shown in fig. 9a, the first preset light source may emit uniformly distributed light, so that the bonding body layer 201 is uniformly irradiated on the whole surface. The first preset light source may be a surface light source. It will be appreciated that the adhesive body layer 201 is substantially the same in hardness at each location after being uniformly irradiated throughout its surface. Herein, the first preset light source may include an ultraviolet light source.

As shown in fig. 9b, the second preset light source 40 may be disposed in the shielding case 50. The shielding cover 50 may be disposed on one side of the bonding body layer 201, and since the front projection of the opening of the shielding cover 50 on the bonding body layer 201 at least surrounds the first area 21, the light emitted from the second preset light source 40 may reach the first area 21 through the opening, so as to achieve the purpose of intensively irradiating the first area 21. The second preset light source 40 may be a wire

It will be appreciated that the order of execution of the steps shown in fig. 9a and 9b may be reversed, and that by two shots (i.e. performing a secondary curing), the first region 21 may receive more light than the second region 22, such that the resulting bonded structure may have a greater hardness in the first region than in the second region.

Illustratively, the inner wall of the shielding case 50 may reflect the light emitted from the second preset light source 40. Since the inner wall of the shielding case can reflect light, the light emitted from the second preset light source 40 can be collected at the opening of the shielding case 50 and emitted.

Illustratively, the shield 50 may be generally cylindrical (or referred to as cylindrical), which may facilitate adjusting the amount of light exiting at different locations of the opening of the shield 50. The second predetermined light source 40 may be located above the axis of the cylindrical shield 50. The axial direction of the cylindrical shield 50 may be parallel to the boundary line of the first region 21 and the second region 22. The axial direction of the cylindrical shielding 50 may be perpendicular to the direction from the first region 21 to the second region 22. The opening is smaller in size than the diameter of the cylindrical shield 50, pointing from the first region 21 to the second region 22. The second preset light source 40 may be a lamp. The direction of extension of the lamp vessel may be parallel to the axial direction of the cylindrical shield 50.

For example, with continued reference to fig. 9b, the second region 22 may include a first sub-region 221 and a second sub-region 222, the first sub-region 221 being connected between the first region 21 and the second sub-region 222, and an orthographic projection of the opening of the shielding can 50 on the adhesive body layer 201 may at least enclose the first region 21 and the first sub-region 221.

For example, the amount of light received by the first sub-region 221 per unit area may be greater than the amount of light received by the second sub-region 222 per unit area, and the amount of light received by the first sub-region 221 per unit area may be less than the amount of light received by the first region 21 per unit area, such that the resulting adhesive structure is prepared to have a hardness in the first sub-region 221 that is greater than the hardness in the second sub-region 222, and the adhesive structure has a hardness in the first sub-region 221 that is less than the hardness in the first region 21.

Illustratively, the amount of light received by the first sub-region 221 in a unit area may be gradually increased in a direction approaching the first region 21 from the boundary of the first sub-region 221 and the second sub-region 222, so that the resulting adhesive structure is prepared such that the hardness of the adhesive structure in the first sub-region 221 is gradually increased in a direction approaching the first region 21 from the boundary of the first sub-region 221 and the second sub-region 222.

Illustratively, the manner in which the amount of light received by the first sub-region 221 per unit area gradually increases in the direction approaching the first region 21 by the intersection of the first sub-region 221 and the second sub-region 222 includes at least one of: linear increase, curve increase, stepwise increase.

Illustratively, the amount of light received at each location of the first region 21 may be the same, such that the stiffness of each location of the first region 21 may be the same.

Alternatively, in a direction from the first region 21 to the second region 22, the amount of light received by the first region 21 per unit area is gradually increased and then gradually decreased, so that the hardness of the first region 21 is gradually increased and then gradually decreased.

Alternatively, the amount of light received by the first region 21 per unit area is gradually reduced from the center of the first region 21 toward the second region 22, so that the resulting bonded structure is prepared such that the hardness of the first region 21 is gradually reduced from the center of the first region 21 toward the second region 22. The manner in which the amount of light received by the first region 21 per unit area gradually decreases from the center of the first region 21 toward the direction approaching the second region 22 includes at least one of: linear decrease, curve decrease, stepwise decrease.

In some alternative embodiments, irradiating the bonding body layer with a predetermined light source such that the first region receives a greater amount of light per unit area than the second region, may include: a photomask is arranged between the preset light source and the bonding body layer, the photomask comprises a first light transmission area and a second light transmission area connected with the first light transmission area, the transmittance of the first light transmission area is larger than that of the second light transmission area, the orthographic projection edge of the first light transmission area on the bonding body layer is overlapped with the edge of the first area, and the orthographic projection edge of the second light transmission area on the bonding body layer is overlapped with the edge of the second area; the mask is uniformly illuminated with a predetermined light source.

As shown in fig. 10, the light emitted from the preset light source can reach the bonding body layer 201 through the mask 60. The transmittance of the first light-transmitting region 61 of the mask 60 is greater than the transmittance of the second light-transmitting region 62 thereof, so that the first light-transmitting region 61 is more transparent to light, and the first region 21 of the bonding body layer 201 is more light-receiving per unit area, so that the prepared bonding structure is larger in the first region 21; the second light-transmitting region 62 may transmit less light, such that the second region 22 of the bond body layer 201 may receive less light per unit area, resulting in a bond structure that is produced that is smaller in the second region 22.

Illustratively, as shown in fig. 11a, the transmittance is the same at each location of the first light transmissive region 61. The amount of light received at each location of the first region 21 may thus be the same, such that the stiffness at each location of the first region 21 may be the same.

Alternatively, as shown in fig. 11b, the transmittance of the first light-transmitting region 61 may be gradually increased and then gradually decreased in a direction from the first light-transmitting region 61 to the second light-transmitting region 62. Alternatively, the transmittance of the first light-transmitting region 61 may gradually decrease from the center of the first light-transmitting region 61 toward the direction approaching the second light-transmitting region 62. The amount of light received by the first region 21 per unit area gradually decreases from the center of the first region 21 toward the second region 22, so that the resulting bonded structure is prepared such that the hardness of the first region 21 gradually decreases from the center of the first region 21 toward the second region 22. The transmittance of the center of the first light transmitting region 61 may be maximized.

Illustratively, the manner in which the transmittance of the first light-transmitting region 61 gradually decreases from the center of the first light-transmitting region 61 toward the direction approaching the second light-transmitting region 62 includes at least one of: linear decrease, curve decrease, stepwise decrease.

By way of example, the second region 22 may comprise a first sub-region 221 and a second sub-region 222, the first sub-region 221 being connected between the first region 21 and the second sub-region 222. Correspondingly, the second light-transmitting region 62 may include a first sub-light-transmitting region 621 and a second sub-light-transmitting region 622, the first sub-light-transmitting region 621 being connected between the first light-transmitting region 61 and the second sub-light-transmitting region 622, the first sub-light-transmitting region 621 having a transmittance smaller than that of the first light-transmitting region 61 and larger than that of the second sub-light-transmitting region 622.

As an example, the transmittance of the first sub-light-transmitting region 621 gradually increases in a direction approaching the first light-transmitting region 61 from the boundary of the first sub-light-transmitting region 621 and the second sub-light-transmitting region 622. The amount of light received by the first sub-region 221 in a unit area may be gradually increased in a direction approaching the first region 21 from the boundary of the first sub-region 221 and the second sub-region 222, so that the resulting adhesive structure is prepared such that the hardness of the adhesive structure in the first sub-region 221 is gradually increased in a direction approaching the first region 21 from the boundary of the first sub-region 221 and the second sub-region 222.

Illustratively, the manner in which the transmittance of the first sub-transmissive region 621 gradually increases in the direction approaching the first transmissive region 61 from the boundary of the first sub-transmissive region 621 and the second sub-transmissive region 622 includes at least one of: linear increase, curve increase, stepwise increase.

For example, the transmittance of each position of the second sub-transmissive region 622 may be the same. The amount of light received at each location of the second sub-region 222 may thus be the same, such that the stiffness of each location of the second sub-region 222 may be the same.

The hardness distribution rules corresponding to fig. 11a and 11b can be realized by the schemes corresponding to fig. 9a and 9b and the scheme corresponding to fig. 10. Compared with the scheme corresponding to fig. 10, the schemes corresponding to fig. 9a and 9b can reduce the waste of light energy, and the light energy is not absorbed by the photomask. Compared with the schemes corresponding to fig. 9a and 9b, the scheme corresponding to fig. 10 can simplify the process and improve the efficiency.

In some alternative embodiments, the bond body layer 201 may include a curing agent. Specifically, the concentration of the curing agent in the first region 21 of the adhesive body layer 201 is greater than the concentration of the curing agent in the second region 22, wherein the concentration of the curing agent in the adhesive body layer 201 is positively correlated to the hardening degree of the adhesive body layer after the adhesive body layer 201 is treated by the preset curing process. The greater the concentration of the curing agent in the bond body layer 201, the greater the hardness thereof after being treated by the preset curing process, and the lesser the concentration of the curing agent in the bond body layer 201, the lesser the hardness thereof after being treated by the preset curing process.

The step S720 of treating the bonding body layer with a preset curing process may specifically include: and uniformly irradiating the bonding body layer by using a preset light source, namely, irradiating the bonding body layer at each position with the same light intensity. The concentration of the curing agent in the bond body layer 201 is positively correlated to the degree of hardening after being irradiated by the predetermined light source. The greater the concentration of the curing agent in the bond body layer 201, the greater the hardness thereof after being irradiated by the preset light source, the smaller the concentration of the curing agent in the bond body layer 201, and the lower the hardness thereof after being irradiated by the preset light source. As shown in fig. 12, the preset light source may emit uniformly distributed light, so that the adhesive body layer 201 is uniformly irradiated on the whole surface. It will be appreciated that since the adhesive body layer 201 has a greater concentration of curing agent in the first region 21 than in the second region 22, the first region 21 will harden to a greater extent than the second region 22 after the adhesive body layer 201 has been uniformly irradiated across the entire surface.

For example, referring to fig. 12, 13a and 13b in combination, the second region 22 may include a first sub-region 221 and a second sub-region 222, the first sub-region 221 being connected between the first region 21 and the second sub-region 222, a concentration of the curing agent in the first sub-region 221 being greater than a concentration of the curing agent in the second sub-region 222, and a concentration of the curing agent in the first sub-region 221 being less than a concentration of the curing agent in the first region 21.

In contrast to the schemes of fig. 9a and 9b, and the scheme of fig. 10, the scheme of fig. 12 may not require a photomask.

As one example, the concentration of the curing agent in the first sub-region 221 gradually increases in a direction approaching the first region 21 from the boundary of the first sub-region 221 and the second sub-region 222. This allows the adhesive structure to be prepared such that the hardness of the adhesive structure in the first sub-region 221 gradually increases in a direction approaching the first region 21 from the boundary between the first sub-region 221 and the second sub-region 222.

Illustratively, the manner in which the concentration of the curing agent in the first sub-region 221 gradually increases in the direction approaching the first region 21 from the boundary of the first sub-region 221 and the second sub-region 222 includes at least one of: linear increase, curve increase, stepwise increase.

Illustratively, the concentration of the curing agent is the same at each location of the second subregion 222 such that the hardness of each location of the second subregion 222 can be the same.

Illustratively, as shown in fig. 13a, the concentration of the curing agent is the same at each location of the first region 21, such that the hardness may be the same at each location of the first region 21.

Alternatively, as shown in fig. 13b, the concentration of the curing agent in the first region 21 is gradually increased and then gradually decreased in a direction from the first region 21 toward the second region 22. Alternatively, the concentration of the curing agent in the first region 21 is gradually decreased from the center of the first region 21 toward the second region 22, so that the resulting bonded structure is prepared such that the hardness of the first region 21 is gradually decreased from the center of the first region 21 toward the second region 22.

Illustratively, the manner in which the concentration of the curing agent in the first region 21 gradually decreases from the center of the first region 21 toward the direction approaching the second region 22 includes at least one of: linear decrease, curve decrease, stepwise decrease.

Illustratively, the curing agent may include a photosensitizer. The material of the photosensitizer includes at least one of the following: 1173 photoinitiator, 184 photoinitiator, TPO photoinitiator, 2959 photoinitiator.

Based on the same inventive concept, the embodiment of the application also provides a foldable display module. As shown in fig. 14, the foldable display module 100 may include a bendable region and a non-bendable region 102 connected to the bendable region 104. The foldable display module 100 may include a plurality of functional layers, for example, may include at least a first functional layer 11 and a second functional layer 12 adjacent to each other. The adhesive structure 20 described in any of the embodiments above may be provided between the first functional layer 11 and the second functional layer 12. The bonding strength is increased by curing to bond the bonding body layer 201 to the functional layers on both sides thereof. The first region 21 of the adhesive structure 20 corresponds to the location of the pliable region 104, the second sub-region 222 of the adhesive structure 20 corresponds to the location of the non-pliable region 102, and the first sub-region 221 corresponds to the location of at least one of the pliable region 104 and the non-pliable region 102. For example, the first sub-region 221 corresponds to the location of the non-inflection region 102. As an example, the first functional layer 11 may include a display panel, and the second functional layer 12 may include a cover plate.

Because the foldable display module provided in the embodiments of the present application includes the bonding structure described in any one of the embodiments, the foldable display module provided in the embodiments of the present application includes the beneficial effects of the bonding structure described in any one of the embodiments, and will not be described in detail herein.

Optionally, as shown in fig. 15, the foldable display module may further include a uv protection layer 13, and the plurality of functional layers may include a display panel 11 and a cover plate 12, the adhesive structure 20 is located between the display panel 11 and the cover plate 12, and the uv protection layer 13 is located on a side of the cover plate 12 away from the adhesive structure 20. The uv protective layer 13 prevents uv light from the ambient light from affecting the hardness of the adhesive structure 20.

The uv-protective layer 13 can absorb uv light in the environment, reduce the influence of uv light in the environment on the hardness of the bonding structure 20, and solve the problem that the hardness change rule does not meet the gradual change requirement because the uv light in the environment irradiates the bonding structure 20 relatively uniformly, if the same curing agent concentration is set in each region of the bonding structure 20, the hardness of different regions of the bonding structure 20 changes with the use time, and the hardness of each region tends to be equal.

The foldable display module in the embodiment of the application can be a mobile phone. The display device can comprise a flexible display panel with a display function only, and also can comprise a flexible display panel with a touch control function. The flexible display panel may be, for example, an organic Light-Emitting Diode (OLED) display panel, a flexible liquid crystal display panel (Liquid Crysthl Displhy, LCD) or other types of flexible display panels. When the mobile phone is in a folded state, the space occupied by the mobile phone is smaller, so that the mobile phone is convenient to store and carry. When the mobile phone is in the unfolding state, the mobile phone can have a larger display area, so that a user can operate and read the mobile phone conveniently.

For example, the foldable display module may be a tablet computer, where when the tablet computer is in a folded state, if the tablet computer is folded towards the display surface side, a part of the tablet computer may be horizontally placed and configured to display a keyboard, so as to form an office operation area, and another part of the tablet computer is obliquely placed and configured to display images or characters, so as to form an office display area. Thus, the user can perform a mobile office operation or a game operation conveniently. For example, the foldable display module can also be an electronic book, and at this time, the electronic book can be made to present a better folding effect imitating a book by bending the electronic book.

For another example, the foldable display module may be a notebook computer, and the flexible display panel may extend to the keyboard region, so as to realize expansion of the display area. In addition, the foldable display module can be further applied to fields of bionic electronics, electronic skin, wearable equipment, vehicle-mounted equipment, internet of things equipment, artificial intelligent equipment and the like, and various application scenes related to bending or folding, and are not repeated here.

Based on the same inventive concept, the embodiment of the application also provides a preparation method of the foldable display module. The preparation method of the foldable display module provided by the embodiment of the application comprises the following steps:

S810, providing a bonding body layer and a plurality of functional layers which are stacked, wherein the bonding body layer is positioned between the plurality of functional layers.

S820, the bonding body layer is processed by a preset curing process to obtain a bonding structure, and the bonding structure bonds the plurality of functional layers.

The preparation method of the foldable display module provided by the embodiment of the application is used for preparing the foldable display module provided by the embodiment, and the preparation method of the foldable display module provided by the embodiment of the application comprises the preparation method of the bonding structure, has the same technical effects and is not repeated here.

Optionally, the method for preparing the foldable display module further includes: after the preset curing process treatment, the uv-protective layer 13 is formed on one side of the laminated structure formed of the adhesive structure and the plurality of functional layers.

These embodiments are not all details described in detail in accordance with the embodiments described hereinabove, nor are they intended to limit the application to the specific embodiments described. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention and various modifications as are suited to the particular use contemplated. This application is to be limited only by the claims and the full scope and equivalents thereof.

Claims

1. A bonding structure comprising at least a first region and a second region connected to the first region, the second region comprising a first sub-region and a second sub-region, the first sub-region being connected between the first region and the second sub-region;

the hardness of the bonding structure in the first subarea is greater than that of the bonding structure in the second subarea, and the hardness of the bonding structure in the first subarea is less than that of the bonding structure in the first subarea;

the hardness of the bonding structure in the first subarea gradually increases in the direction of approaching the first area from the junction of the first subarea and the second subarea;

the hardness of the bonding structure in the direction from the first region to the second region is gradually increased and then gradually decreased.

2. The bonding structure according to claim 1, wherein,

in a direction approaching the first region from an intersection of the first and second subregions, the manner in which the hardness of the bond structure at the first subregion gradually increases includes at least one of: linear increase, curve increase, stepwise increase.

3. The bonding structure according to claim 1, wherein the bonding structure has the same hardness at each location of the second subregion.

4. The bonding structure of claim 1, wherein the bonding structure has a greater concentration of curing agent in the first subregion than in the second subregion, and the bonding structure has a lesser concentration of curing agent in the first subregion than in the first region.

5. The bonding structure of claim 4, wherein the bonding structure increases in concentration of curing agent at the first subregion in a direction proximate the first region from the intersection of the first subregion and the second subregion.

6. The bonding structure of claim 5, wherein the manner in which the concentration of curing agent in the first subregion of the bonding structure increases gradually in a direction approaching the first region from the intersection of the first subregion and the second subregion comprises at least one of: linear increase, curve increase, stepwise increase.

7. The bonding structure of claim 4, wherein the bonding structure has the same concentration of curing agent at each location of the second subregion.

8. The bonding structure of claim 4, wherein the bonding structure comprises an optical adhesive and the curing agent comprises a photosensitizer.

9. The bonding structure according to claim 1, wherein,

the hardness of the bonding structure in the first region gradually decreases from the center of the first region to the direction approaching the second region.

10. The bonding structure of claim 9, wherein the manner in which the stiffness of the bonding structure in the first region gradually decreases from the center of the first region toward the second region comprises at least one of: linear decrease, curve decrease, stepwise decrease.

11. The bonding structure of claim 1, wherein the bonding structure gradually increases and then gradually decreases in the concentration of the curing agent in the first region in a direction from the first region toward the second region.

12. The bonding structure of claim 11, wherein the concentration of the curing agent in the first region of the bonding structure decreases gradually from the center of the first region toward the second region.

13. The bonding structure of claim 12, wherein the manner in which the concentration of the curing agent in the bonding structure in the first region gradually decreases from the center of the first region toward the direction toward the second region comprises at least one of: linear decrease, curve decrease, stepwise decrease.

14. The bonding structure according to claim 1, wherein the body of the bonding structure in the first region and the body thereof in the second region are a unitary structure.

15. A bonding structure comprising at least a first region and a second region connected to the first region, the second region comprising a first sub-region and a second sub-region, the first sub-region being connected between the first region and the second sub-region;

the concentration of the curing agent of the bonding structure in the first subarea is larger than that of the bonding structure in the second subarea, and the concentration of the curing agent of the bonding structure in the first subarea is smaller than that of the bonding structure in the first subarea;

the adhesive structure gradually increases in the concentration of the curing agent in the first subarea in the direction of approaching the first area from the junction of the first subarea and the second subarea;

The concentration of the curing agent in the first area is gradually increased and then gradually decreased in the direction from the first area to the second area;

the bonding structure comprises an optical adhesive, and the curing agent comprises a photosensitizer.

16. The bonding structure according to claim 15, wherein the bonding structure comprises,

in a direction approaching the first region from an intersection of the first and second subregions, the manner in which the binder structure gradually increases in the concentration of the curing agent in the first subregion includes at least one of: linear increase, curve increase, stepwise increase.

17. The bonding structure of claim 15, wherein the bonding structure has the same concentration of curing agent at each location of the second subregion.

18. The bonding structure according to claim 15, wherein the bonding structure comprises,

the concentration of the curing agent in the first area of the bonding structure gradually decreases from the center of the first area to the direction approaching the second area.

19. The bonding structure according to claim 18, wherein the bonding structure comprises,

the manner in which the concentration of the curing agent in the first region gradually decreases from the center of the first region toward the direction approaching the second region includes at least one of: linear decrease, curve decrease, stepwise decrease.

20. The bonding structure according to claim 15, wherein the bonding structure comprises,

the body of the bonding structure in the first area and the body of the bonding structure in the second area are of an integrated structure.

21. A method of making a bonded structure, the method comprising:

processing the bonding body layer by a preset curing process to obtain a bonding structure, wherein the hardness of the bonding structure in the first subarea is higher than that of the bonding structure in the second subarea, the hardness of the bonding structure in the first subarea is lower than that of the bonding structure in the first area, and the hardness of the bonding structure in the first subarea is gradually increased in the direction of approaching the first area from the junction of the first subarea and the second subarea; the hardness of the bonding structure in the direction from the first area to the second area is gradually increased and then gradually decreased;

The treating the bonding body layer with a preset curing process includes:

irradiating the bonding body layer by using the preset light source, so that the light quantity received by the first subarea in unit area is larger than the light quantity received by the second subarea in unit area, and the light quantity received by the first subarea in unit area is smaller than the light quantity received by the first area in unit area, wherein the hardening degree of the bonding body layer irradiated by the preset light source is positively correlated with the light quantity received by the bonding body layer;

the step of irradiating the bonding body layer with the preset light source to make the amount of light received by the first sub-region in a unit area larger than the amount of light received by the second sub-region in a unit area, and make the amount of light received by the first sub-region in a unit area smaller than the amount of light received by the first region in a unit area, includes:

a second preset light source is arranged in a shielding cover and irradiates the bonding body layer, the shielding cover comprises an opening, and orthographic projection of the opening on the bonding body layer at least surrounds the first area and the first subarea;

The inner wall of the shielding cover can reflect the light rays emitted by the second preset light source;

an orthographic projection of the second predetermined light source on the bonding body layer overlaps a center of the first region.

22. The method of claim 21, wherein the shield is generally cylindrical.

23. The method of claim 21, wherein the step of determining the position of the probe is performed,

24. The method of claim 21, wherein the step of determining the position of the probe is performed,

the hardness of the bonding structure at each position of the second subarea is the same.

25. The method of claim 21, wherein the step of determining the position of the probe is performed,

26. The method of claim 25, wherein the step of determining the position of the probe is performed,

the manner in which the hardness of the adhesive structure in the first region gradually decreases from the center of the first region toward the direction approaching the second region includes at least one of: linear decrease, curve decrease, stepwise decrease.

27. A method of making a bonded structure, the method comprising:

the treating the bonding body layer with a preset curing process includes:

a photomask is arranged between the preset light source and the bonding body layer, the photomask comprises a first light transmission area and a second light transmission area connected with the first light transmission area, the second light transmission area comprises a first sub light transmission area and a second sub light transmission area, the first sub light transmission area is connected between the first light transmission area and the second sub light transmission area, the transmittance of the first sub light transmission area is smaller than that of the first light transmission area and larger than that of the second sub light transmission area, the orthographic projection edge of the first light transmission area on the bonding body layer coincides with the edge of the first area, and the orthographic projection edge of the second light transmission area on the bonding body layer coincides with the edge of the second area;

uniformly irradiating the photomask by using the preset light source;

the transmittance of the first light-transmitting area gradually decreases from the center of the first light-transmitting area to the direction approaching the second light-transmitting area;

The transmittance of the first sub-light-transmitting area gradually increases in a direction from the first sub-light-transmitting area and the second sub-light-transmitting area to the first light-transmitting area.

28. The method of claim 27, wherein the step of determining the position of the probe is performed,

the transmittance of each position of the second sub-light-transmitting area is the same.

29. The method of claim 27, wherein the step of determining the position of the probe is performed,

30. The method of claim 27, wherein the step of determining the position of the probe is performed,

31. The method of claim 27, wherein the step of determining the position of the probe is performed,

32. The method of claim 31, wherein the step of determining the position of the probe is performed,

33. A method of making a bonded structure, the method comprising:

the concentration of the curing agent of the bonding body layer in the first subarea is larger than that of the bonding body layer in the second subarea, and the concentration of the curing agent of the bonding structure in the first subarea is smaller than that of the bonding body layer in the first area, wherein the concentration of the curing agent in the bonding body layer is positively correlated with the hardening degree of the bonding body layer after the bonding body layer is treated by the preset curing process;

The treating the bonding body layer with a preset curing process includes:

uniformly irradiating the bonding body layer by using the preset light source so that the light intensity irradiated to each position of the bonding body layer is the same;

the concentration of the curing agent in the first subarea gradually increases in a direction approaching the first subarea from the junction of the first subarea and the second subarea;

34. The method of claim 30, wherein the step of determining the position of the probe is performed,

35. The method of claim 30, wherein the step of determining the position of the probe is performed,

36. The method of claim 30, wherein the step of determining the position of the probe is performed,

37. The method of claim 30, wherein the step of determining the position of the probe is performed,

the curing agent concentration of the bonding structure at each position of the second subarea is the same.

38. The method of claim 30, wherein the step of determining the position of the probe is performed,

39. The method of claim 38, wherein the step of determining the position of the probe is performed,

40. The utility model provides a collapsible display module assembly, its characterized in that includes can buckle district and with can buckle district connection's non-bending area, collapsible display module assembly still includes:

A plurality of functional layers; and

the adhesive structure of any one of claims 1 to 20 disposed between two adjacent functional layers;

the first region corresponds to the position of the bendable region, the second sub-region corresponds to the position of the non-bendable region, and the first sub-region corresponds to the position of at least one of the bendable region and the non-bendable region; the hardness of the first subarea is between the hardness of the first subarea and the hardness of the second subarea so as to balance the stress at the junction of the bendable area and the non-bendable area of the foldable display module.

41. The foldable display module of claim 40, wherein the display module is configured to display a plurality of images,

the foldable display module assembly further comprises a UV-proof protection layer, the plurality of functional layers comprise a display panel and a cover plate, the bonding structure is located between the display panel and the cover plate, the UV-proof protection layer is located on one side, away from the bonding structure, of the cover plate, the UV-proof protection layer is used for absorbing ultraviolet rays in the environment, and the hardness influence of the ultraviolet rays in the environment on the bonding structure is reduced.

42. The foldable display module of claim 40, wherein the display module is configured to display a plurality of images,

And forming a UV-protective layer on one side of the laminated structure formed by the bonding structure and the plurality of functional layers after a preset curing process treatment, wherein the preset curing process treatment comprises UV curing.

43. The foldable display module of claim 41, wherein each region of the adhesive structure is provided with the same concentration of curing agent.