Patent ID: 12191433

DETAILED DESCRIPTION OF THE DISCLOSURE

The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present disclosure. It should be noted that, for ease of description, only components related to the technical solutions of the embodiments of the present disclosure are shown in the drawings, and other components are omitted. In addition, it should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other without conflict.

A chip on film is usually formed by a chip soft film packaging technology, also known as a flexible packaging substrate, which directly mounts the driving chip on the soft film carrier tape. For a display module containing the chip on film, it is usually composed of a driver chip, a display panel, a printed circuit board, other passive components (such as resistors, capacitors, etc.), a flexible circuit board, and an anisotropic conductive film (ACF). One end of the flexible circuit board is connected with the display panel, and the other end is connected with the printed circuit board. Then, the chip bumps on the driving chip and the inner pins on the flexible circuit board are bonded by thermocompression to achieve the installation purpose of high density, light weight, small volume, and free bending of the display module package.

Generally, a large-size display panel is provided with multiple chip on films on the side, one end of the chip on film is bonded with the display panel, and the other end away from the display panel is bonded with the printed circuit board assembly (that is, an entire manufacturing process of a SMT loading or DIP plug-in on a bare PCB, referred to as PCBA).

After the chip on film has been bonded with the PCBA, the display module needs to continue to circulate in the production line to perform operations such as attaching the heat dissipating film, connecting the patch cord, and lighting test to the chip on film and PCBA. However, during the production line circulation, packaging or transportation of display modules (especially large or medium-sized display modules such as notebook (NB), vehicle-mounted modules, etc.), and even during standard operations such as jig adsorption, the peeling of the chip on film often occurs, which makes the chip on film detach from the display panel and/or the PCBA and cannot achieve normal electrical connection.

The inventor(s) of the present application found that there are two main reasons that cause the peeling of the chip on film in the display module:

First, the distance between the chip on film and the edge of the display panel is relatively small, about 10 mm. When the operator picks up and places the display module, if the display panel is slightly tilted or has too large moving radian, the chip on film may collide with objects (such as trays, countertops, jigs, etc.), causing damage or peeling of the chip on film at the bonding position with the display panel and/or PCBA.

Second, one end of the chip on film is bonded with the display panel, and the other end is bonded with the PCBA. The chip on film is very easy to be pulled by the PCBA, which causes damage or peeling of the chip on film at the bonding position with the display panel and/or PCBA.FIG.1illustrates a schematic diagram of a structure of a display module in the related art, and the dotted frame in the figure illustrates that peeling of the chip on film occurs at the bonding position with the display panel under the external force.

Currently, for the problem of peeling of the chip on film, the only hope is that the operator adopts a jig to absorb the display module, and the display module is picked up by the standard operation and as flat as possible to avoid hitting the trays or foreign objects. However, this kind of personnel operation standard cannot solve the problem fundamentally, and the actual effect is not good. In the actual production process, the phenomenon of peeling of the chip on film still frequently occurs.

In view of this, an embodiment of the present disclosure provides a display module, andFIG.2illustrates a schematic structural diagram of the display module1. As illustrated inFIG.2, the display module1comprises: a display panel14comprising a substrate (not illustrated), which is located at the bottom of the display panel14; a chip on film4(not illustrated inFIG.2, please refer toFIG.5) connected to the display panel14; a circuit board5connected to the chip on film4, the circuit board5may be, for example, a printed circuit board; and a first film layer3, which is attached to the surfaces of the display panel14and the circuit board5facing away from the substrate (that is, the upper surfaces of the display panel14and the circuit board5in the figure) and covers at least the chip on film4and the circuit board5.

One end of the first film layer3is attached to a side of the display panel14close to the chip on film4, and the other end of the first film layer3is attached to a side of the circuit board5away from the chip on film4. Therefore, the first film layer3is over the chip on film4and the circuit board5and covers the chip on film4and the circuit board5, and therefore covers the bonding area of the chip on film4with the display panel14, and the bonding area of the chip on film4with the circuit board5. Through this arrangement, the first film layer3can better fix the chip on film4and the circuit board5, and can better protect the bonding areas of the chip on film4, thereby reducing or even avoiding the peeling of the chip on film4when pulled or scratched by foreign objects, improving the production yield of the display module1, increasing production efficiency, and reducing production costs.

FIG.3illustrates a schematic diagram of the structure of the first film layer3. Referring toFIGS.2and3, in some embodiments, the first film layer3may comprise a plurality of openings7. The circuit board5usually comprises electronic components such as a capacitor, a timing controller (T-CON), a power management integrated circuit (PMIC), and ELIC (any layer interconnection). The plurality of openings7of the first film layer3at least need to expose the integrated circuit chip and the timing controller of the circuit board5. In an alternative embodiment, the plurality of openings7of the first film layer3expose electronic components of the circuit board5such as a capacitor, T-CON, PMIC, ELIC, etc. By providing the openings7, it is possible to avoid scratching the circuit board5when the first film layer3is peeled off or attached.

As illustrated inFIG.3, the first film layer3comprises a first adhesive area15which comprises a first part1501and a second part1502extending along a first direction D1. The adhesion of the first part1501and the second part1502of the first adhesive area15may be 3-10 gf/inch. Such adhesion can prevent damage to the display components (such as the display panel14, the chip on film4, the circuit board5, etc.) when the first film layer3is peeled off. In addition, recycling can also be achieved.

The first film layer3also comprises a non-adhesive area10, which is located between the first part1501and the second part1502of the first adhesive area15, and the non-adhesive area10and an orthographic projection of the chip on film4on the first film layer3at least partially overlap. In other words, in a direction perpendicular to the first film layer3, the non-adhesive area10corresponds to the chip on film4. The term “non-adhesive area” means that the adhesion of the first film layer3at this area is zero, or has an extremely small adhesion that can be ignored. In some embodiments, the non-adhesive area10of the first film layer3is coated with ink, so that the adhesion of the non-adhesive area10is zero. The ink can be a colorless and transparent ink or a colored ink.

That is to say, the first film layer3is arranged in segments, and the upper and lower first part1501and the second part1502have adhesion respectively to adhere to the display panel14and the circuit board5, the middle part is the non-adhesive area10without adhesion to avoid the chip on film4. It should be noted that the boundary of the non-adhesive area10does not completely coincide with the boundary of the chip on film4, and can be specifically adjusted according to the area of the electrical elements on the chip on film4during specific settings. By providing the non-adhesive area10without any adhesion corresponding to the chip on film4, it is possible to avoid pulling the chip on film4during the process of tearing the first film layer3, thereby further avoiding the peeling of the chip on film4caused by pulling. In an alternative embodiment, the non-adhesive area10can also be a low-adhesive area with very low adhesion. By reducing the adhesion of the first film layer3at the non-adhesive area10, the pulling of the chip on film4during the tearing can be reduced.

The four sides of the first film layer3respectively extend beyond the chip on film4and the circuit board5, and the first film layer3covers a part of the substrate of the display panel14. As illustrated inFIG.2, the left side of the first film layer3extends beyond the left edge contours of the chip on film4and the circuit board5, the right side of the first film layer3extends beyond the right edge contours of the chip on film4and the circuit board5, the upper side of the first film layer3extends beyond the upper edge contours of the chip on film4and the circuit board5, and the lower side of the first film layer3extends beyond the lower edge contours of the chip on film4and the circuit board5. The area of the first film layer3is larger than the occupied area of the chip on film4and the circuit board5, so that it can cover the chip on film4and the circuit board5well, so as to achieve a good fixing effect and protection effect on the chip on film4and the circuit board5, to prevent the chip on film4from peeling.

The thickness of the first film layer3in the direction perpendicular to the substrate can be any appropriate value, and the embodiment of the present disclosure does not specifically limit the thickness of the first film layer3. In an example, the thickness of the first film layer3in the direction perpendicular to the substrate may be less than or equal to 0.1 mm.

The material of the first film layer3may be any suitable material, and the embodiment of the present disclosure does not specifically limit the material of the first film layer3. In an example, the material of the first film layer3is polyethylene glycol terephthalate (PET). PET, for example, has higher hardness and better stiffness.

As illustrated inFIG.2, the display module1may also comprise a second film layer2.FIG.5illustrates a schematic diagram of the display module1omitting the first film layer3and only comprising the second film layer2. Referring toFIGS.2and5, the second film layer2is attached to the substrate of the display panel14and covers the surfaces of the display panel14, the chip on film4, and the circuit board5facing away from the first film layer3. In other words, the second film layer2is attached to the lower surface of the display panel14and covers the lower surfaces of the display panel14, the chip on film4, and the circuit board5. The four sides of the second film layer2respectively extend beyond the display panel14, the chip on film4and the circuit board5. As illustrated in the figure, the left side of the second film layer2extends beyond the left edge contours of the display panel14, the chip on film4, and the circuit board5, the right side of the second film layer2extends beyond the right edge contours of the display panel14, the chip on film4, and the circuit board5, the upper side of the second film layer2extends beyond the upper edge contour of the display panel14, and the lower side of the second film layer2extends beyond the lower edge contour of the circuit board5. In an example, the four sides of the second film layer2respectively extend beyond the display panel14, the chip on film4, and the circuit board5by at least 3-5 mm.

The second film layer2is attached to the substrate of the display panel14to provide a good support and buffer for the entire display module1, which can effectively reduce the risk of stress mark on the display panel14. In addition, for foldable products such as a notebook computer, the substrate of the display panel14is usually made of plastic material (required for folding), and the surface hardness of the substrate is usually about 1H. Such hardness can easily cause the substrate to be scratched during packaging and transportation. By attaching the second film layer2to the substrate of the display panel14and making the coverage area of the second film layer2larger than that of the substrate, the substrate of the display panel14can be well protected to avoid scratches during transportation. In addition, the second film layer2can also play a good role in fixing the display panel14, the chip on film4and the circuit board5, and prevent the chip on film4from peeling under the impact of external force.

As illustrated inFIGS.2and3, the first film layer3further comprises the second adhesive areas11located on both sides of the first adhesive area15and extending along the second direction D2. The adhesion of the second adhesive areas11is greater than that of the first adhesive area15. In an example, the adhesion of the second adhesive areas11is 30 gf/inch. The second adhesive areas11extend beyond the chip on film4and the circuit board5. The adhesion of the second film layer2may be 3-10 gf/inch. The opposite left and right sides of the second film layer2respectively extend beyond the chip on film4and the circuit board5, and the second adhesive areas11of the first film layer3are adhered to the opposite left and right sides of the second film layer2, respectively. By making the second adhesive areas11of the first film layer3have higher adhesion, the adhesion and limiting effect of the first film layer3can be enhanced. By making the second adhesive areas11of the first film layer3adhere to the opposite left and right sides of the second film layer2, the second adhesive areas11can be prevented from adhering to products (such as the chip on film4and the circuit board5). That is to say, the second adhesive areas11of the first film layer3must avoid the chip on film4and the circuit board5to prevent the chip on film4and the circuit board5from being pulled when the second adhesive areas11with greater adhesion are torn, so as to prevent the chip on film4from peeling. The combination of the first film layer3and the second film layer2can better fix the chip on film4and the circuit board5of the display module1, thereby avoiding the peeling of the chip on film4in the display module1.

FIG.4Aillustrates a schematic diagram of a structure of the second film layer2. As illustrated in the figure, the second film layer2comprises at least two sub-film layers separated from each other, and the at least two sub-film layers are both attached to the substrate of the display panel14.FIG.4Aillustrates as an example that the second film layer2comprises three sub-film layers separated from each other. For large-size products such as 10 inches to 17 inches, considering the convenience of tearing the second film layer2, this segmented solution can be adopted. Generally, the normal phone size of 6 inches is as the segmentation standard. For example, for a phone within 7 inches, a complete second film layer2can be used, that is, a complete and undivided film layer2is attached to the substrate of the display panel14. For vehicle-mounted display screens of about 12 inches, the second film layer2can be divided into two sections, and each section is attached to the substrate of the display panel14to facilitate tearing. For notebook products from 17 inches to 24 inches, the second film layer2can be divided into three sections, and each section is attached to the substrate of the display panel14to facilitate tearing. According to the size of the display panel14, in a direction from the upper edge6of the display panel14to the circuit board5, the second film layer2can be divided into several sections and attached to the bottom substrate of the display panel14.

FIG.4Billustrates another schematic diagram of the structure of the second film layer2. As illustrated in the figure, in a direction from the display panel14to the circuit board5, the width of the second film layer2along the first direction D1gradually increases. For example, the width of a part of the second film layer2close to the display panel14is W1, and the width of another part of the second film layer2close to the circuit board5is W2, W1<W2.

FIG.4Cillustrates a schematic diagram of another structure of the second film layer2. As illustrated in the figure, in some embodiments, the second film layer2may adopt a combination of a segmented type and a tapered type. For example, the second film layer2can be divided into three sections, in a direction from the upper edge6of the display panel14to the circuit board5, the three sections are respectively the first section, the second section, and the third section. In applications, each section has even width along the first direction D1, but the widths of individual sections are as follows: the width W1of the first section<the width W2of the second section<the width W3of the third section. Of course, it can also be set that the width of each section gradually increases along the direction from the display panel14to the circuit board5, and the widths of the sections also gradually increase along this direction. For example, the width of the first section gradually increases along the direction from the display panel14to the circuit board5, the width of the second section gradually increases along the direction from the display panel14to the circuit board5, the width of the third section gradually increases along the direction from the display panel14to the circuit board5, and the widest width of the first section<the widest width of the second section<the widest width of the third section.

In the embodiment of the present application, a segmented or tapered second film layer2is provided, which facilitates the attachment and tearing of the second film layer2, and is particularly suitable for medium and large-sized display screens.

The thickness of the second film layer2in the direction perpendicular to the substrate can be any appropriate value, and the embodiment of the present disclosure does not specifically limit the thickness of the second film layer2. In an example, the thickness of the second film layer2in the direction perpendicular to the substrate is 0.3-0.5 mm. In an example, the thickness of the first film layer3in the direction perpendicular to the substrate may be less than or equal to 0.1 mm. It should be noted that the materials of the first film layer3and the second film layer2can be finished films or customized films according to requirements. Accordingly, there are two processes for thickening the first film layer3and the second film layer2. One process is to reattach a thin film layer, the number of layers to be reattached can exceed 4, for example, a film with a thickness of 50 um, and 4 layers are reattached, a film with a thickness of 200 um can be obtained. The cost of this process is relatively high, but the buffer effect of the film layer can be significantly strengthened by multi-layer reattaching. Another process is to directly extrude a thick film of a required thickness, and then cut it in the form of a sheet (after the film is thickened, it cannot be transported in the form of a roll like a conventional film, generally, when the thickness exceeds 0.2 mm, it needs to be transported in the form of a sheet).

The material of the second film layer2may be any suitable material, and the embodiment of the present disclosure does not specifically limit the material of the second film layer2. For example, the material of the second film layer2may be selected from one or more of polyethylene glycol terephthalate (PET), polyethylene (PE), thermoplastic polyurethane elastomer (also known as thermoplastic polyurethane rubber, TPU). PET has higher hardness and better stiffness than PE; PE is soft, low cost; TPU has moderate hardness and good toughness, but the cost is the highest. In specific applications, different materials can be selected according to specific needs. The foregoing is only an exemplary description. When materials are specifically selected, other polymer materials may also be selected as the second film layer2to realize the inventive concept provided by the embodiments of the present application.

Referring back toFIG.2, both sides of the first film layer3extending in the second direction D2may comprise first lugs13, and both sides of the second film layer2extending in the second direction D2may comprise second lugs12. By providing the lugs, on the one hand, the tearing and adhering of the first film layer3and the second film layer2can be facilitated; on the other hand, the lugs can be symmetrically and evenly distributed so as to fit into the trays9used in the production line circulation process to form a limit, as illustrated inFIG.6.

As illustrated inFIG.9, the first film layer3may also comprise a connecting strip8adhered to the display module1. The connecting strip8can be adhered to the second film layer2or can be adhered to the circuit board5. During the production process, the first film layer3is not always covered on the upper surfaces of the chip on film4and the circuit board5. When it is necessary to process the chip on film4and the circuit board5, the first film layer3needs to be temporarily removed from the upper surfaces of the chip on film4and the circuit board5. After the processing is completed, the first film layer3is re-attached to the upper surfaces of the chip on film4and the circuit board5. By providing the connecting strip8on the first film layer3, it can be ensured that the first film layer3is not separated from the display module1when the first film layer3is temporarily removed from the upper surfaces of the chip on film4and the circuit board5. Thereby, the loss of the first film layer3can be prevented, and recycling of the first film layer3can be realized.

According to another aspect of the present disclosure, a display device is provided.FIG.7illustrates a block diagram of the display device700, which comprises the display module1described in any of the previous embodiments. The display device700may be any suitable display device, comprising but not limited to terminal devices with a display function such as mobile phones, televisions, tablet computers, notebook computers, wearable devices, or the like.

Since the display device700can have substantially the same technical effects as the display module1described in the previous embodiments, for the sake of brevity, the technical effects of the display device700will not be repeated here.

According to still another aspect of the present disclosure, a method for manufacturing a display module is provided.FIG.8illustrates a flowchart of a method800for manufacturing a display module. The method800is applicable to the display module1described in any of the previous embodiments. The steps of the method800are described below in conjunction withFIG.2andFIG.8.

Step S801: providing a display panel14, the display panel14comprising a substrate;

Step S802: connecting a chip on film4to the display panel14;

Step S803: connecting a circuit board5to the chip on film4;

Step S804: attaching a first film layer3to the surfaces of the display panel14and the circuit board5facing away from the substrate, so that the first film layer3covers at least the chip on film4and the circuit board5;

Step S805: temporarily removing the first film layer3to expose the chip on film4and the circuit board5during an operation of the chip on film4and the circuit board5; and

Step S806: resetting the first film layer3after completing the operation of the chip on film4and the circuit board5.

In some embodiments, before the step S804, the method800may further comprise the following step: attaching a second film layer2to the substrate of the display panel14so that the second film layer2covers the surfaces of the display panel14, the chip on film4, and the circuit board5facing away from the first film layer3.

FIG.9illustrates a schematic diagram of the structure of the display module1in different stages of the method800. In stage (a), providing the display panel14, the chip on film4connected to the display panel14, and the circuit board5connected to the chip on film4, and attaching the second film layer2to the substrate of the display panel14, the four sides of the second film layer2respectively extend beyond the display panel14, the chip on film4and the circuit board5. In stage (b), attaching the first film layer3to the surfaces of the display panel14and the circuit board5facing away from the substrate, so that the first film layer3covers at least the chip on film4and the circuit board5. In stage (c), during the transfer of the display module in the production workshop due to the requirements of the assembly line, the first film layer3and the second film layer2are kept attached to better fix the chip on film4and the circuit board5, so that the chip on film4can be reduced or even prevented from peeling when it is pulled or scratched by foreign objects. In stage (d), when it is necessary to process the chip on film4and the circuit board5, for example, sticking the heat dissipation film, sticking the tape, connecting the patch cord, lighting test, etc., temporarily removing the first film layer3from the upper surfaces of the chip on film4and the circuit board5to expose the chip on film4and the circuit board5. Due to the existence of the connecting strip8, the first film layer3will not be separated from the display module, thereby preventing the first film layer3from being lost.

The lighting test refers to inputting the timing information of the display module, the gray-scale voltages of the red, green, and blue pixels, data signals and the like to the display module to check whether the display module can work normally. In stage (e), after the operation of the chip on film4and the circuit board5is completed, the first film layer3is reattached to the surfaces of the display panel14and the circuit board5facing away from the substrate, so that the first film layer3covers at least the chip on film4and the circuit board5. In stage (f), the display module1is loaded into the tray9for packaging and fixing.

On the other hand, the present disclosure provides a method for preparing the first film layer3and the second film layer2of the display module1, and the method comprises:

T1, forming a second film layer2with a predetermined thickness;

T2, forming a second film layer2with a predetermined shape and attaching it to the bottom of the display module1, or attaching the second film layer2to the bottom of the display module1to form the second film layer2with a predetermined shape;

T3, forming a first film layer3with a predetermined thickness;

T4, forming a first film layer3with a predetermined shape;

T5, forming a first film layer3with a predetermined adhesion;

T6, attaching the first film layer3to the top of the display module1;

T7, adhering the second adhesive areas11of the first film layer3beyond the chip on film4and the circuit board5to the left and right sides of the second film layer2beyond the chip on film4and the circuit board5.

In steps T1and T3, “forming a second film layer2with a predetermined thickness” and “forming a first film layer3with a predetermined thickness” comprise:

forming the second film layer2or the first film layer3with a predetermined thickness by a multi-layer reattaching manner; or,

preparing the second film layer2or the first film layer3with a predetermined thickness by extrusion molding.

The thickness of the second film layer2is 0.3-0.5 mm, and the thickness of the first film layer3is ≤0.1 mm. The materials of the second film layer2and the first film layer3can be finished films or customized films according to requirements. Accordingly, there are two processes for thickening the first film layer3and the second film layer2. One process is to reattach a thin film layer, the number of layers to be reattached can exceed 4, for example, a film with a thickness of 50 um, and 4 layers are reattached, a film with a thickness of 200 um can be obtained. The cost of this process is relatively high, but the buffer effect of the film layer can be significantly strengthened by multi-layer reattaching. Another process is to directly extrude a thick film of a required thickness, and then cut it in the form of a sheet (after the film is thickened, it cannot be transported in the form of a roll like a conventional film, generally, when the thickness exceeds 0.2 mm, it needs to be transported in the form of a sheet).

In step T2, the second film layer2can be attached to the display module1, and then a specific contour can be formed by punching with a tool; or, the second film layer2can be first cut to form a specific contour, and then attach the second film layer2to the bottom of the display module1through an optical alignment device and a manual jig. The way of attaching can be carried out by roller rolling. The four sides of the second film layer2respectively extend beyond the display panel14, the chip on film4, and the circuit board5by at least 3-5 mm.

In step T4, since the openings7are provided on the first film layer3, the first film layer3can be opened first, and then a specific contour is formed, and then attaching the first film layer3to the display module1. The components on the circuit board5that the openings7can avoid comprise a capacitor, T-CON, PMIC, ELIC, etc., the key is to avoid IC and T-CON.

In step T5, “forming a first film layer3with a predetermined adhesion” comprises:forming a first adhesive area15with a predetermined adhesion and a second adhesive area11with a predetermined adhesion on the first film layer3;forming a non-adhesive area10with a predetermined shape in a part of the first adhesive area15by applying ink.the adhesion of the first adhesive area15of the first film layer3is 3-10 gf/inch, the adhesion of the second adhesive areas11is 30 gf/inch, and the non-adhesive area10may not have adhesion.

It should be noted that the embodiment of the present application provides a way of applying ink to make a part of the first adhesive area15become a non-adhesive area. The present application is not limited to this, and the non-adhesive area10can also be set by applying adhesive glue in sections. On the premise of not violating the idea of the present disclosure, various ways of realizing the non-adhesive area10all fall within the protection scope of the present application.

In step T6, attaching the first film layer3to the top of the display module1means attaching the first film layer3to the display panel14and the circuit board5through an optical alignment device and a bonding jig so as to cover the upper surfaces of the chip on film4and the circuit board5. It should be noted that the positions of the openings7of the first film layer3should be aligned with the corresponding electrical elements on the circuit board5.

In step T7, completing the further attaching of the second film layer2and the first film layer3, adhering the second adhesive areas11of the first film layer3beyond the chip on film4and the circuit board5to the left and right sides of the second film layer2beyond the chip on film4and the circuit board5. The adhesion of the second adhesive areas11is 30 gf/inch. Rolling and attaching can be completed by roller rolling and other methods.

It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or parts, these elements, components, regions, layers and/or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Thus, a first element, component, region, layer or part discussed above could be termed a second element, component, region, layer or part without departing from the teachings of the present disclosure.

Spatially relative terms, such as “below”, “above”, “left”, “right”, “top”, “bottom”, and the like, may be used herein for ease of description to describe one element or feature's relationship with another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of a device in use or operation in addition to the orientations depicted in the figures. For example, if a device in the figures is turned over, elements described as “below”, “beneath” or “under” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary terms “below” and “under” can encompass both orientations of “above” and “below”. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may be interpreted accordingly. In addition, it will also be understood that when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or there may also be one or more intervening layers.

The terminologies used herein are for the purpose of describing particular embodiments only and are not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprise” and/or “include”, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. In the description of this specification, the description with reference to the terms “one embodiment”, “another embodiment”, etc. means that a specific feature, structure, material, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine different embodiments or examples and features of different embodiments or examples described in this specification without contradicting each other.

It will be understood that when an element or layer is referred to as being “on”, “connected to”, “coupled to”, or “adjacent to” another element or layer, it can be directly on, connected, coupled, or adjacent to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being “directly on,” “directly connected to”, “directly coupled to”, or “directly adjacent to” another element or layer, there are no intervening elements or layers. Embodiments of the disclosure are described herein with reference to schematic illustrations of idealized embodiments (and intermediate structures) of the disclosure. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the disclosure should not be construed as limited to the particular shapes of regions illustrated herein, but are to include deviations in shapes that result, for example, from manufacturing. Accordingly, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shapes of the regions of a device and are not intended to limit the scope of the disclosure.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and/or the present specification and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The above are only specific implementations of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, and the changes or substitutions should be encompassed by the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.