Flexible display module and electronic device including the same

An electronic device is provided. The electronic device includes a housing, a display, a middle plate, an adhesive layer, a support layer, and a coating layer. The housing includes a front plate facing a direction, a rear plate facing an opposite direction, and a lateral member surrounding a space between the front and rear plate. The display is configured to be seen through the front plate, and includes a first and second surface. The middle plate is disposed between the display and the rear plate, and includes a surface facing the display, and a recess. The adhesive layer is attached to the display, and the support layer is disposed between the adhesive layer and the middle plate. The coating layer is disposed between the support layer and the adhesive layer and is disposed in a first portion overlapped with the recess when viewed from the display.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is based on and claims priority under 35 U.S.C. § 119(a) of a Korean patent application number 10-2018-0168215, filed on Dec. 24, 2018, in the Korean Intellectual Property Office, and of a Korean patent application number 10-2019-0018900, filed on Feb. 19, 2019, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

The disclosure relates to a flexible display module and an electronic device including the same.

2. Description of Related Art

Normally an electronic device has a display to visually offer information to a user. Such displays have been developed and improved in various aspects with the growths of electronic devices. For example, the resolution becomes higher to realize an enhanced image quality, and the thickness becomes thinner to reduce power consumption. In recent years, a flexible display that allows a variation in shape in accordance with a change in shape of the electronic device has been studied and developed.

In the flexible display, a support layer is attached over the entire area of the display to support the display. Thus, when the support layer is deformed by external force, the deformed shape may be transferred to a window surface of the display. In addition, surface irregularities (e.g., differences in thickness) of a middle plate in the display may be exposed to the window surface.

SUMMARY

Aspects of the disclosure are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the disclosure is to provide an electronic device that prevents a deformed shape from appearing on a window surface of a display even when a support layer attached to the display is deformed by an external force.

In accordance with an aspect of the disclosure, an electronic device is provided. The electronic device includes a housing including a front plate facing a first direction, a rear plate facing a second direction opposite to the first direction, and a lateral member surrounding a space between the front plate and the rear plate, a display configured to be seen through at least a portion of the front plate and including a first surface facing the first direction and a second surface facing the second direction, a middle plate disposed between the display and the rear plate, including a third surface facing the second surface of the display and a recess formed on the third surface, an adhesive layer attached to the second surface of the display, a support layer disposed between the adhesive layer and the middle plate, and a coating layer disposed between the support layer and the adhesive layer and disposed in a first portion overlapped with the recess when viewed from the display.

In accordance with another aspect of the disclosure, an electronic device is provided. The electronic device includes a housing including a front plate facing a first direction, a rear plate facing a second direction opposite to the first direction, and a lateral member surrounding a space between the front plate and the rear plate, a display configured to be seen through at least a portion of the front plate and including a first surface facing the first direction and a second surface facing the second direction, a middle plate disposed between the display and the rear plate, including a third surface facing the second surface of the display and a recess formed on the third surface, an adhesive layer attached to the second surface of the display and including an opening formed in a first portion overlapped with the recess when viewed from the display, and a support layer disposed between the adhesive layer and the middle plate.

In accordance with another aspect of the disclosure, a flexible display module is provided. The flexible display module includes a front plate facing a first direction and configured to be foldable, a display configured to be seen through at least a portion of the front plate and including a first surface facing the first direction and a second surface facing a second direction opposite to the first direction, an adhesive layer attached to the second surface of the display, a support layer combined with the adhesive layer, and a coating layer disposed between at least part of the support layer and the adhesive layer.

DETAILED DESCRIPTION

FIG.1is a view showing an unfolded state of an electronic device according to an embodiment of the disclosure.

FIG.2is a view showing a folded state of an electronic device according to an embodiment of the disclosure.

Referring toFIGS.1and2, in an embodiment, the electronic device10may include a foldable housing500, a hinge cover530that covers a foldable portion of the foldable housing500, and a flexible or foldable display100(which may hereinafter, be referred to as “display100”) disposed in a space defined by the foldable housing500. In the disclosure, a surface on which the display100is disposed may, for example, be referred to as a first surface or a front surface of the electronic device10. In addition, the opposite surface of the front surface may, for example, be referred to as a second surface or a rear surface of the electronic device10. Also, a surface surrounding a space between the front and rear surfaces may, for example, be referred to as a third surface or a lateral surface of the electronic device10.

In an embodiment, the foldable housing500may include a first housing structure (e.g., a first housing)510, a second housing structure (e.g., a second housing)520having a sensor area524, a first rear cover580, and a second rear cover590. The foldable housing500of the electronic device10is not limited to the shape and configuration shown inFIGS.1and2, and may be implemented with any other shape and configuration. For example, and without limitation, in another embodiment, the first housing510and the first rear cover580may be integrally formed, and also the second housing520and the second rear cover590may be integrally formed.

In the illustrated embodiment, the first housing510and the second housing520are disposed at both sides with respect to a folding axis (indicated by ‘A’), and may have a generally symmetric shape with respect to the folding axis (A). As will be described in greater detail below, the first and second housings510and520may have different angles or distances therebetween, depending on whether the electronic device10is in a flat (e.g., unfolded) state, a folded state, or an intermediate state. In the illustrated embodiment, the second housing520has the sensor area524in which various sensors are disposed. Excepting the provision of the sensor area524, both housings may be substantially symmetrical in shape.

In an embodiment, as shown inFIG.1, the first housing510and the second housing520may together include a recess for accommodating the display100therein. In the illustrated embodiment, the recess may have two or more different widths in a direction perpendicular to the folding axis (A) because of the sensor area524.

For example, the recess may have a first width (W1) between a first portion510aof the first housing510parallel to the folding axis (A) and a first portion520aof the second housing520formed at one edge of the sensor area524, and a second width (W2) between a second portion510bof the first housing510parallel to the folding axis (A) and a second portion520bof the second housing520not corresponding to the sensor area524and being parallel to the folding axis (A). In this example, the second width (W2) may be greater than the first width (W1). In other words, the first portion510aof the first housing510and the first portion520aof the second housing520, which have asymmetrical shapes, define the first width (W1) of the recess, whereas the second portion510bof the first housing510and the second portion520bof the second housing520, which have symmetrical shapes, define the second width (W2) of the recess. In an embodiment, the first portion520aand the second portion520bof the second housing520may have different distances from the folding axis (A). The width of the recess is not limited to the illustrated example. In various embodiments, the recess may have a plurality of different widths depending on the shape of the sensor area524or asymmetrical shapes of the first and second housings510and520.

In an embodiment, at least a portion of the first and second housings510and520may comprise a metallic or non-metallic material having a selected rigidity value to support the display100.

In an embodiment, the sensor area524may occupy a certain region adjacent to one corner of the second housing520. The arrangement, shape, and size of the sensor area524are not limited to the illustrated example. For example, in other embodiments, the sensor area524may be disposed at any other corner of the second housing520or at any position between top and bottom corners. In an embodiment, components for performing various functions may be embedded in the electronic device10and exposed to the front surface of the electronic device10through the sensor area524or through one or more openings provided in the sensor area524. In various embodiments, such components may include various types of sensors, which may include, for example, and without limitation, at least one of a front camera, a receiver, a proximity sensor, or the like.

The first rear cover580is disposed on one side of the folding axis on the rear surface of the electronic device10. The first rear cover580may have, for example, a substantially rectangular periphery surrounded by the first housing510. Similarly, the second rear cover590is disposed on the other side of the folding axis on the rear surface of the electronic device10, and a substantially rectangular periphery thereof may be surrounded by the second housing520.

In the illustrated embodiment, the first rear cover580and the second rear cover590may have a substantially symmetrical shape with respect to the folding axis (A). This is, however, not essential. In another embodiment, the electronic device10may include the first and second rear covers580and590having various shapes. In still another embodiment, the first rear cover580may be integrally formed with the first housing510, and the second rear cover590may be integrally formed with the second housing520.

In an embodiment, the first rear cover580, the second rear cover590, the first housing510, and the second housing520may together define a space in which various components of the electronic device10(e.g., a printed circuit board or a battery) are disposed. In an embodiment, one or more components may be disposed near and visually exposed to the rear surface of the electronic device10. For example, at least a portion of a sub display190may be visually exposed through a first rear area582of the first rear cover580. In another embodiment, one or more components or sensors may be visually exposed through a second rear area592of the second rear cover590. In various embodiments, such sensors may include, for example, and without limitation, a proximity sensor and/or a rear camera, or the like.

Referring toFIG.2, the hinge cover530is disposed between the first housing510and the second housing520and may be configured to cover an internal component (e.g., a hinge). In an embodiment, depending whether the electronic device10is in a flat state or in a folded state, the hinge cover530may be hidden by a part of the first and second housings510and520or exposed to the outside.

For example, when the electronic device10is in the flat state as shown inFIG.1, the hinge cover530may be hidden by the first and second housings510and520, thus being not exposed. Also, when the electronic device10is in the folded state (e.g., a fully folded state) as shown inFIG.2, the hinge cover530may be exposed to the outside between the first and second housings510and520. In the case of an intermediate state in which the first and second housings510and520are folded at a certain angle, the hinge cover530may be partially exposed to the outside between the first and second housings510and520. The exposed area in the intermediate state may be smaller than that in the fully folded state. In an embodiment, the hinge cover530may have a curved surface.

The display100may be disposed in the space defined by the foldable housing500. For example, the display100may be mounted in the recess formed by the foldable housing500while forming most of the front surface of the electronic device10.

Therefore, the front surface of the electronic device10may include the display100, a portion of the first housing510adjacent to the display100, and a portion of the second housing520. In addition, the rear surface of the electronic device10may include the first rear cover580, a portion of the first housing510adjacent to the first rear cover580, the second rear cover590, and a portion of the second housing520adjacent to the second rear cover590.

The display100may refer to a display that allows at least a portion thereof to be deformed into a curved surface. In an embodiment, as shown inFIG.1, the display100may include a folding area103, a first area101disposed on one side with respect to the folding area103(e.g., the left side of the folding area103shown inFIG.1), and a second area102disposed on the other side with respect to the folding area103(e.g., the right side of the folding region103shown inFIG.1).

The divided areas of the display100illustrated inFIG.1is an example only, and the display100may be divided into a plurality of areas (e.g., two, four or more) according to the structure or function thereof. For example, unlike being divided into areas based on the folding area103or the folding axis (A) each parallel to the y-axis in the illustratedFIG.1embodiment, the display100in another embodiment may be divided into areas based on another folding area or folding axis (e.g., each parallel to the x-axis).

The first area101and the second area102may have a symmetrical shape as a whole with respect to the folding area103. However, unlike the first area101, the second area102may have a cut portion to expose the sensor area524, resulting in an asymmetrical shape. Therefore, the first and second areas101and102may have a symmetrical portion and an asymmetrical portion.

Hereinafter, in each particular state of the electronic device10, the operations of the first and second housings510and520and the respective areas of the display100will be described.

In an embodiment, when the electronic device10is in a flat state (e.g.,FIG.1), the first housing510and the second housing520are disposed to form an angle of 180 degrees and face the same direction. Thus, the surfaces of the first and second areas101and102of the display100form an angle of 180 degrees with each other and face the same direction (e.g., the front direction of the electronic device). In addition, the folding area103may form the same plane as the first and second areas101and102.

In an embodiment, when the electronic device10is in a folded state (e.g.,FIG.2), the first housing510and the second housing520are disposed to face each other. Thus, the surfaces of the first and second areas101and102of the display100form a small angle (e.g., between 0 and 10 degrees) and face each other. In addition, the folding area103may be formed to have partially a curved surface having a certain curvature.

In an embodiment, when the electronic device10is in an intermediate state, the first housing510and the second housing520are disposed to form a certain angle. Thus, the surfaces of the first and second areas101and102of the display100form a certain angle which is greater than the angle in the folded state and smaller than the angle in the flat state. In addition, the folding area103may be formed to have partially a curved surface having a certain curvature. This curvature is smaller than the curvature in the folded state.

FIG.3is an exploded perspective view illustrating an example foldable electronic device according to an embodiment.

Referring toFIG.3, in an embodiment, the electronic device10may include a display unit (e.g., including a display)20, a bracket assembly (e.g., including a bracket)30, a substrate unit (e.g., including a substrate)600, the first housing510, the second housing520, the first rear cover580, and the second rear cover590. In the disclosure, the display unit20may be also referred to as a display module or a display assembly.

The display unit20may include the display100and at least one plate or layer140on which the display100is mounted. In an embodiment, the plate140may be disposed between the display100and the bracket assembly30. The display100may be disposed on at least a portion of one surface (e.g., the upper surface inFIG.3) of the plate140. The plate140may have a shape corresponding to the display100. For example, a portion of the plate140may have a shape corresponding to a cut portion104of the display100.

The bracket assembly30may include a first bracket410, a second bracket420, a hinge structure (e.g., including a hinge) disposed between the first and second brackets410and420, the hinge cover530covering the hinge structure, and a wiring member430(e.g., a flexible printed circuit (FPC)) intersecting with the first and second brackets410and420.

In an embodiment, the bracket assembly30may be disposed between the plate140and the substrate unit600. For example, the first bracket410may be disposed between the first area101of the display100and a first substrate610of the substrate unit600. The second bracket420may be disposed between the second area102of the display100and a second substrate620of the substrate unit600.

In an embodiment, the wiring member430and the hinge structure may be disposed, at least in part, inside the bracket assembly30. The wiring member430may be disposed in a direction (e.g., the x-axis direction) that crosses the first and second brackets410and420. The wiring member430may be disposed in a direction perpendicular to a folding axis (e.g., the y-axis or the folding axis (A) inFIG.1) of the folding area103of the electronic device10.

As mentioned above, the substrate unit600may include the first substrate610disposed to correspond to the first bracket410, and the second substrate620disposed to correspond to the second bracket420. The first and second substrates610and620may be disposed in a space formed by all or substantially all of the bracket assembly30, the first housing510, the second housing520, the first rear cover580, and the second rear cover590. On the first substrate610and the second substrate620, electronic components for implementing various functions of the electronic device10may be mounted.

The first housing510and the second housing520may be assembled to be combined with both sides of the bracket assembly30in a state where the display unit20is combined with the bracket assembly30. As will be described below, the first housing510and the second housing520may be combined with the bracket assembly30by sliding on both sides of the bracket assembly30.

In an embodiment, the first housing510may have a first rotation supporting surface512, and the second housing520may have a second rotation supporting surface522corresponding to the first rotation supporting surface512. Each of the first and second rotation supporting surfaces512and522may have a curved surface corresponding to the curved surface included in the hinge cover530.

In an embodiment, when the electronic device10is in the flat state (e.g.,FIG.1), the first and second rotation supporting surfaces512and522cover the hinge cover530so that the hinge cover530may not be exposed or be exposed in a relatively small amount to the rear surface of the electronic device10. Meanwhile, when the electronic device10is in the folded state (e.g.,FIG.2), the first and second rotation supporting surfaces512and522rotate along the curved surfaces included in the hinge cover530so that the hinge cover530may be exposed to the rear surface of the electronic device10.

FIG.4is an exploded perspective view of an electronic device according to an embodiment of the disclosure.

Referring toFIG.4, the electronic device according to an embodiment may include a flexible display module800, with a front plate710, a display810, middle plates720and730, an adhesive layer820, and/or a support layer830.

The front plate710according to an embodiment may be disposed to face a first direction. The first direction may refer to a direction of a front surface of the electronic device. InFIG.4, the first direction indicates an upward direction. The front plate710may refer to a window that has one surface exposed to the outside of the electronic device and receives a user's touch for manipulating a screen or entering an input action. In case of a foldable electronic device that is capable of being folded or unfolded, the front plate710should be folded or unfolded together with the electronic device. Thus, the front plate710may be formed of a material that is elastically deformable. For example, a plastic polymer material such as polyimide may be used.

Although not shown, a rear plate according to an embodiment may be disposed to face a second direction opposite to the first direction. The rear plate may be also disposed substantially parallel to the front plate710. In addition, although not shown, a lateral member may be disposed to surround a space formed by both the front plate710and the rear plate. The lateral member may be formed integrally with or separately from the rear plate. The front plate710, the rear plate, and the lateral member may constitute a housing that forms the overall appearance of the electronic device.

The middle plates720and730according to an embodiment may be disposed in the space between the front plate710and the rear plate and may each include a third surface facing the first direction. The third surface of the middle plate720may include a recess721formed as a concave shape in the second direction. The recess721may refer to a space in which various electronic components817(seeFIG.5) of the electronic device are arranged. For example, the electronic components817disposed in the recess721may include a display driver integrated circuit (IC) for controlling the display810to be described later.

The display810according to an embodiment may include a first surface811(e.g., a front surface) facing the first direction and a second surface813(e.g., a rear surface) facing the second direction. The display810may be a flexible display. The first surface811of the display810may be combined with the front plate710, so that the display810may be folded together with the front plate710. The display810combined with the front plate710may be viewed through at least a portion of the front plate710. Although not shown, the display810may include a polarizer plate, a panel, a cushion layer, and the like. When power is supplied, the display810may emit light under the control of the display driver IC to display various kinds of information.

The support layer830according to an embodiment may be combined with the second surface813of the display810. The support layer830may be formed of a material, such as a metallic material, that enables the formation of a thin film and guarantees a certain level of strength. For example, stainless steel may be used for the support layer830. The support layer830may serve as a base frame such that the front plate710and the display810, which are formed to be easily deformed, may maintain a flat shape. The support layer830may be mounted on and combined with the middle plates720and730or the rear plate to fasten the display810to the electronic device. In an illustrated example, the support layer830is combined with the middle plates720and730. The support layer830may be divided into two parts along a central axis where the front plate710and the display810are folded.

In an embodiment, the support layer830and the display810may be combined with each other through the adhesive layer820. The adhesive layer820may be, for example, a pressure sensitive adhesive (PSA). The adhesive layer820may combine the support layer830and the display810in a way of surface contact. The adhesive layer820may include a fourth surface attached to the second surface of the display and a fifth surface attached to the support layer830. The adhesive layer820may be divided into two parts as resembling the support layer830. A certain portion of the adhesive layer820may not combine the support layer830and the display810. For example, an opening821may be formed in a first portion of the adhesive layer820without combining the support layer830and the display810. The first portion of the adhesive layer820may correspond to the position of the recess721formed in the middle plate720when the support layer830is combined with the middle plates720and730.

When an external force is applied to the electronic device according to an embodiment, the applied external force may be delivered to a certain portion of the support layer830and cause plastic deformation of the support layer830. That is, a deformed portion of the support layer830may not be restored to its original state. For example, when a certain pressure is applied to the surface of the front plate710at a portion corresponding to the position of the recess721of the middle plate720, the support layer830may be plastically deformed in a concave form. At this time, stress may be concentrated on portions of the support layer830being in contact with edges of the recess721, and the support layer830may be bent along the edges of the recess721and sunk into the recess721. As a result, the plastic deformation may occur.

In addition, when an external force is applied to the electronic device according to another embodiment, the applied external force may be delivered to a certain portion of the support layer830and cause temporary deformation of the support layer830. Then, when the applied external force is removed, a deformed portion of the support layer830may be restored to its original state. For example, when a certain pressure is applied to the surface of the front plate710at a portion corresponding to the position of the recess721of the middle plate720, the support layer830may be temporarily deformed in a concave form. At this time, stress may be concentrated on portions of the support layer830being in contact with edges of the recess721, and the support layer830may be bent along the edges of the recess721and sunk into the recess721. Thereafter, when the applied pressure is removed, the deformed support layer830may be restored to its original state by elasticity. In addition, forming the opening821in the adhesive layer820to partially separate the support layer830and the display810may prevent the deformation of the support layer830from being transferred to the display810and the front plate710.

FIG.5is a view showing a flexible display module, seen from a direction of a second surface of a display, according to an embodiment of the disclosure.

Referring toFIG.5, a view is provided showing the flexible display module800, seen from a direction of the second surface813(seeFIG.4) of the display810(seeFIG.4), according to an embodiment of the disclosure. That is,FIG.5shows a rear surface of the flexible display module800.

According to an embodiment, on the rear surface of the flexible display module800, a flexible printed circuit board (FPCB)815and the electronic components817such as a display driver IC for controlling the display810may be disposed. The FPCB815may extend from a lateral surface of the display810and bend toward the second surface813. The electronic components817are accommodated in the recess721(seeFIGS.4and6) formed in the middle plate720(seeFIGS.4and6).

FIG.6is a perspective view showing a recess of an electronic device according to an embodiment of the disclosure.

Referring toFIG.6, the middle plate720may include the third surface facing the first direction, and include the recess721formed on the third surface to be recessed in the second direction. The recess721may refer to a certain space for accommodating various electronic components817(seeFIG.5) disposed in the electronic device. Depending on the number and positions of such electronic components817embedded in the electronic device, a plurality of recesses may be formed at different locations. For example, as shown inFIG.5, the recess721may be formed to correspond to a position where the electronic components817such as the display driver IC are disposed. The recess721may have a depth corresponding to the thickness of the electronic components817to prevent an increase in overall thickness of the electronic device with edges723.

FIGS.7A and7Bare cross-sectional views showing an electronic device according to various embodiments of the disclosure.

FIGS.7A and7Bcorrespond to cross-sectional views taken along the line A-A ofFIG.5. Specifically,FIG.7Ashows a state before an external force is applied to the electronic device, andFIG.7Bshows a state after an external force is applied to the electronic device. AlthoughFIGS.7A and7Bdepict respective layers as being separated from each other, this is merely for convenience of distinction between adjacent layers. In fact, neighboring layers are attached to each other or very close together.

Referring toFIGS.7A and7B, when an external force is applied to the electronic device, especially when the external force is applied to a specific portion of the support layer830, the support layer830may be plastically deformed and may not be restored to its original state. For example, when an external force is applied to a portion of the surface of the front plate710corresponding to the recess721of the middle plate720or the first portion of the adhesive layer820, the support layer830may be plastically deformed in a concave form. At this time, stress may be concentrated on portions of the support layer830being in contact with edges723of the recess721, and the support layer830may be bent along the edges723of the recess721and sunk into the recess721. As a result, the plastic deformation may occur. If the support layer830and the display810are attached as a whole by the adhesive layer820, the shape of the plastically deformed support layer830may be transferred to the front plate710. As a result, the user may recognize this.

However, in the electronic device according to an embodiment as shown inFIGS.7A and7B, the opening821is formed in the first portion of the adhesive layer820to partially remove the adhesive layer820and thereby partially separate the support layer830and the display810. The formation position of the opening821corresponds to the recess721. By forming the opening821, the deformed shape of the support layer830may not be transferred to the display810and the front plate710even when the support layer830is plastically deformed by an external force.

In an embodiment, the area of the opening821formed in the adhesive layer820may be greater than that of the recess721. Referring to the cross-sectional view ofFIG.7A, when the recess721has a width as indicated by ‘X’, the opening821may be formed to have a greater width by ‘α’ on each side. In other words, the width of the opening821may become ‘X+2α’. Forming the opening821to be greater than the recess721is for effectively preventing the deformation of the support layer830from being transferred to the display810and the front plate710.

FIGS.8A and8Bare cross-sectional views showing an electronic device according to various embodiments of the disclosure.

FIGS.8A and8Bcorrespond to cross-sectional views taken along the line A-A ofFIG.5. Specifically,FIG.8Ashows a state before an external force is applied to the electronic device, andFIG.8Bshows a state after an external force is applied to the electronic device. AlthoughFIGS.8A and8Bdepict respective layers as being separated from each other, this is merely for convenience of distinction between adjacent layers. In fact, neighboring layers are attached to each other or very close together.

Referring toFIGS.8A and8B, as similar toFIGS.7A and7B, the opening821is formed in the first portion of the adhesive layer820to partially remove the adhesive layer820and thereby partially separate the support layer830and the display810. The formation position of the opening821corresponds to the recess721. By forming the opening821, the deformed shape of the support layer830may not be transferred to the display810and the front plate710even when the support layer830is plastically deformed by an external force.

Even if the adhesive layer820has a very small thickness, an empty space between the display810and the support layer830, produced by the opening821of the adhesive layer820, may be unfavorable. Therefore, the electronic device according to another embodiment may further include a support plate840that is disposed in the opening821. The support plate840is for almost removing the empty space between the display810and the support layer830. The support plate840may have the same thickness as or a smaller thickness than that of the adhesive layer820.

The support plate840may include a sixth surface facing the first direction and a seventh surface facing the second direction. The sixth surface of the support plate840may be a surface in contact with the display810, and the seventh surface may be a surface in contact with the support layer830. The support plate840may fill the empty space between the display810and the support layer830and prevent the display810and the support layer830from meeting. In order for the support plate840to be stably disposed in the opening821of the adhesive layer820, an adhesive material may be coated on the sixth or seventh surface to be attached to the display810or the support layer830.

In this embodiment, the area of the opening821formed in the adhesive layer820may be greater than that of the recess721. Referring to the cross-sectional view ofFIG.8A, when the recess721has a width as indicated by ‘X’, the opening821may be formed to have a greater width by ‘α’ on each side. In other words, the width of the opening821may become ‘X+2α’. Forming the opening821to be greater than the recess721is for effectively preventing the deformation of the support layer830from being transferred to the display810and the front plate710. In addition, the support plate840may be larger than the recess721but smaller than the opening821. The support plate840may be formed as small as ‘A’ on each side than the opening821. In other words, the width of the support plate840may become ‘X+2(α−A)’.

FIG.9is a cross-sectional view showing a recess having a modified edge in an electronic device according to an embodiment of the disclosure.

Referring toFIG.9, a cross-sectional view is provided showing the recess721having a modified edge725in an electronic device according to an embodiment of the disclosure. AlthoughFIG.9depicts respective layers as being separated from each other, this is merely for convenience of distinction between adjacent layers. In fact, neighboring layers are attached to each other or very close together.

As described above, when an external force is applied to the electronic device, especially when an external force is applied to a portion of the surface of the front plate710corresponding to the recess721of the middle plate720or the first portion of the adhesive layer820, the support layer830may be plastically deformed in a concave form. At this time, stress may be concentrated on portions of the support layer830being in contact with edges of the recess721, and the support layer830may be bent along the edges of the recess721and sunk into the recess721. As a result, the plastic deformation may occur. Therefore, in this embodiment, the edges of the recess721may be modified through a rounding or chamfering process. The modified edges725may reduce stress concentration and thereby minimize plastic deformation of the support layer830.

FIG.10is an exploded perspective view of an electronic device according to an embodiment of the disclosure, andFIG.11is a cross-sectional view of the electronic device shown inFIG.10according to an embodiment of the disclosure.

Referring toFIGS.10and11, the electronic device according to an embodiment may include a flexible display module1000, with the front plate710, the display810with the first surface811and second surface813, the middle plates720and730with recess721, and a coating layer1031interposed between a support layer1030and an adhesive layer1020. AlthoughFIG.11depicts respective layers as being separated from each other, this is merely for convenience of distinction between adjacent layers. In fact, neighboring layers are attached to each other or very close together.

In the following description, differences between the electronic device shown inFIGS.10and11and the electronic device shown inFIG.4will be discussed in greater detail.

In this embodiment, the support layer1030and the display810may be combined with each other through the adhesive layer1020. The adhesive layer1020may be a pressure sensitive adhesive (PSA), for example, and may combine the support layer1030and the display810in a way of surface contact.

However, it is possible to partially separate the support layer1030and the display810. For example, the coating layer1031may be formed in a first portion of the support layer1030so as to separate the support layer1030and the adhesive layer1020. The first portion of the support layer1030may correspond to the position of the recess721formed in the middle plate720.

The coating layer1031may be disposed between the support layer1030and the adhesive layer1020. The coating layer1031may be separately manufactured and disposed, or may be formed by surface treatment of the support layer1030or the adhesive layer1020. For example, the coating layer1031may be a silver (Ag) coating, an aluminum (Al) coating, or an anti-finger (AF) print coating. The thickness of the coating layer1031may be about 5 μm. The area of the coating layer1031may be greater than that of the recess721.

FIG.12is an exploded perspective view of an electronic device according to an embodiment of the disclosure, andFIG.13is a cross-sectional view of an electronic device according to an embodiment of the disclosure.

Referring toFIGS.12and13, the electronic device according to various embodiments may include a flexible display module1200, with the front plate710, a display1210, the middle plates720and730, an adhesive layer1220, a support layer1230, a support plate1240, an edge adhesive layer1250, and/or a buffer layer1260.

The front plate710may refer to a window that receives a user's touch for manipulating a screen or entering an input action. In case of a foldable electronic device that is capable of being folded or unfolded, the front plate710should be folded or unfolded together with the electronic device. Thus, the front plate710may be formed of a material that is elastically deformable. For example, a plastic polymer material such as polyimide may be used.

The display1210may be a flexible display. The display1210may be combined with the front plate710through a first surface1211thereof, so that the display1210may be folded together with the front plate710. The display1210may be composed of a panel1210a, a cushion layer1210c, a panel adhesive1210b, and the like. When power is supplied, the display1210may emit light under the control of the display driver IC to display various kinds of information.

The middle plates720and730may offer places for arranging various kinds of electronic components embedded in the electronic device. The middle plates720and730may include various structures, such as recesses, holes, and protrusions, for mounting various electronic components. Therefore, the surfaces of the middle plates720and730may be uneven, and irregularities or operations may be formed.

The support layer1230may be combined with a second surface1213of the display1210. The support layer1230may be formed of a material, such as a metallic material, that enables the formation of a thin film and guarantees a certain level of strength. For example, the support layer1230may be formed of stainless steel or a clad which is a combination of stainless steel and aluminum. The support layer1230may serve as a base frame such that the front plate710and the display1210, which are formed to be easily deformed, may maintain a flat shape. The support layer1230may be divided into two parts along a central axis where the front plate710and the display1210are folded.

The support layer1230and the display1210may be combined with each other through the adhesive layer1220. The adhesive layer1220may be, for example, a pressure sensitive adhesive (PSA).

The support plate1240may fill an empty space (i.e., a space having no adhesive) formed between the display1210and the support layer1230. The support plate1240may have the same thickness as or a smaller thickness than that of the adhesive layer1220.

The edge adhesive layer1250may combine edges of the support layer1230and edges of the middle plates720and730. The edge adhesive layer1250may be formed to have an area sufficient to overcome an elastic force of the buffer layer1260and sufficiently secure a combining force between the support layer1230and the middle plates720and730. The edge adhesive layer1250may be divided into two parts at an axis along which the support layer1230is folded.

The buffer layer1260may be positioned between the support layer1230and the middle plates720and730. In addition, the buffer layer1260may be disposed on the same layer as the edge adhesive layer1250without overlapping with the edge adhesive layer1250. For example, the buffer layer1260may be disposed in portions of the middle plates720and730except for a portion where the edge adhesive layer1250is disposed. The buffer layer1260may be formed of a sponge or any other elastic material. The buffer layer1260may be combined with the support layer1230through one surface thereof, and may be divided into two parts along an axis of folding the support layer1230. The buffer layer1260may be formed thicker than the edge adhesive layer1250. The buffer layer1260may be partially compressed when the support layer1230and the middle plates720and730are attached by the edge adhesive layer1250.

When a flexible display module1200according to various embodiments is mounted on the middle plates720and730, surface irregularities or operations of the middle plates720and730may be visually recognized to the user through the front plate710. Specifically, when irregularities or operations are formed on the surfaces of the middle plates720and730, gaps between the support layer1230of the flexible display module1200and the middle plates720and730may be narrow in certain portions and relatively wide in the other portions. This may cause the front plate710to be much deformed toward the middle plates720and730in portions having wide gaps and less deformed in portions having narrow gaps. As a result, the front plate710may have an uneven surface, and a curvy or wavy phenomenon may appear on the front plate710. The buffer layer1260according to various embodiments may absorb the surface irregularities or operations of the middle plates720and730and elastically support the support layer1230with an elastic force generated by compression. Elastically supporting the support layer1230through the buffer layer1260may prevent the curvy or wavy phenomenon from appearing on the front plate710and allow the front plate710to have an even surface.

According to an embodiment of the disclosure, an electronic device may include a housing including a front plate710facing a first direction, a rear plate facing a second direction opposite to the first direction, and a lateral member surrounding a space between the front plate710and the rear plate, a display810seen through at least a portion of the front plate710and including a first surface811facing the first direction and a second surface813facing the second direction, a middle plate720and730disposed between the display810and the rear plate, including a third surface facing the second surface813of the display810, and including a recess721formed on the third surface, an adhesive layer820attached to the second surface813of the display810and including an opening821formed in a first portion overlapped with the recess721when viewed from the display810, and a support layer830disposed between the adhesive layer820and the middle plate720and730.

The display810may include a flexible display.

The display810may include a flexible printed circuit board815extending from a lateral surface of the display810and bent toward the second surface813, and at least one electronic component817mounted on the flexible printed circuit board815and facing the second direction.

The recess721may accommodate the at least one electronic component817.

The opening821may have an area greater than an area of the recess721when viewed from the display810.

The electronic device may further include a support plate840disposed in the opening821and attached to the second surface813of the display810, and the support plate840may include a sixth surface facing the first direction and a seventh surface facing the second direction, include an adhesive material between the sixth surface and the second surface813, and include no adhesive material between the seventh surface and the support layer830.

The support plate840may have a same thickness as or a smaller thickness than a thickness of the adhesive layer820.

The electronic device may further include a support plate840disposed in the opening821between the display810and the support layer830and including a sixth surface facing the first direction and a seventh surface facing the second direction.

The support plate840may include an adhesive material between the sixth surface and the second surface813, and include no adhesive material between the seventh surface and the support layer830.

The support plate840may include no adhesive material between the sixth surface and the second surface813, and include an adhesive material between the seventh surface and the support layer830.

An edge of the recess721may be modified through a rounding or chamfering process.

According to an embodiment of the disclosure, an electronic device may include a housing including a front plate710facing a first direction, a rear plate facing a second direction opposite to the first direction, and a lateral member surrounding a space between the front plate710and the rear plate, a display810seen through at least a portion of the front plate710and including a first surface811facing the first direction and a second surface813facing the second direction, a middle plate720and730disposed between the display810and the rear plate, including a third surface facing the second surface813of the display810, and including a recess721formed on the third surface, an adhesive layer1020attached to the second surface813of the display810, a support layer1030disposed between the adhesive layer1020and the middle plate720and730, and a coating layer1031disposed between the support layer1030and the adhesive layer1020and disposed in a first portion overlapped with the recess721when viewed from the display810.

The coating layer1031may have an area greater than an area of the recess721when viewed from the display810.

The coating layer1031may include at least one of a silver (Ag) coating, an aluminum (Al) coating, or an anti-finger (AF) print coating.

According to an embodiment of the disclosure, a flexible display module800,1000or1200may include a front plate710facing a first direction and being foldable, a display810seen through at least a portion of the front plate710and including a first surface facing the first direction and a second surface facing a second direction opposite to the first direction, an adhesive layer820or1020attached to the second surface of the display810, a support layer830or1030combined with the adhesive layer820, and a coating layer1020disposed at least in part between the support layer830or1030and the adhesive layer820or1020.