JP2024038922A - Flexible display device metal support, method of manufacturing the same, and flexible display device - Google Patents

Abstract

To provide a flexible display device metal support capable of reducing a curvature radius of a bent portion of a flexible display device, a method of manufacturing the same, and a flexible display device.SOLUTION: A flexible display device metal support 10 is provided, comprising a first metal layer 20 having a first surface 20a and a second surface 20b, and a second metal layer 30 stacked on the second surface 20b of the first metal layer 20. A main metal material constituting the first metal layer 20 is different from a main metal material constituting the second metal layer 30. The second metal layer 30 has a first opening 31.SELECTED DRAWING: Figure 5

Description

The present disclosure relates to a metal support for a flexible display device, a method for manufacturing the same, and a flexible display device.

In recent years, foldable display devices such as smartphones and tablets have become known. As such a display device, there is a flexible display device that has a bendable portion in a portion thereof (for example, Patent Document 1).

Patent No. 6603764

In recent years, there has been a demand for making the shape of the bent portion smaller when the flexible display device is folded. That is, it is required to further reduce the radius of curvature of the bent portion. However, if the shape of the bent portion is made smaller, it becomes difficult to maintain the strength of the bent portion.

The present disclosure provides a metal support for a flexible display device, a method for manufacturing the same, and a flexible display device that can further reduce the radius of curvature of a bent portion of the flexible display device.

Embodiments of the present disclosure relate to [1] to [12] below.

[1] A metal support for a flexible display device, comprising: a first metal layer having a first surface and a second surface; and a second metal layer laminated on the second surface of the first metal layer. A metal support for a flexible display device, wherein a main metal material forming the first metal layer and a main metal material forming the second metal layer are different from each other, and the second metal layer has a first opening. body.

[2] The metal support for a flexible display device according to [1], further comprising a third metal layer laminated on the first surface of the first metal layer.

[3] The metal support for a flexible display device according to [2], wherein the third metal layer has a second opening.

[4] According to [2] or [3], at least a portion of the first opening of the second metal layer and at least a portion of the second opening of the third metal layer overlap in plan view. A metal support for a flexible display device as described above.

[5] At least a portion of the first opening of the second metal layer and at least a portion of the second opening of the third metal layer are misaligned in plan view, [2] to [4] ] The metal support for a flexible display device according to any one of the above.

[6] The metal support for a flexible display device according to [2], wherein the third metal layer does not have an opening.

[7] The second metal layer has a patterned portion around the first opening, and the patterned portion includes a portion formed in an island shape, a line shape, or a mesh shape. The metal support for a flexible display device according to any one of [6].

[8] A flexible display device comprising a display member and the metal support for a flexible display device according to any one of [1] to [7], which supports the display member.

[9] A method for manufacturing a metal support for a flexible display device, including a first metal layer having a first surface and a second surface, and a second metal layer laminated on the second surface of the first metal layer. and a step of preparing a laminate, wherein the main metal material forming the first metal layer and the main metal material forming the second metal layer are different from each other, and the second metal of the laminate. a step of providing a second protective layer having a second protective layer opening on the layer; and a step of forming a first opening in the second metal layer by etching the second metal layer of the laminate. A method for manufacturing a metal support for a flexible display device, comprising:

[10] The laminate further includes a third metal layer laminated on the first surface of the first metal layer, and the method for manufacturing the metal support for a flexible display device further includes a third metal layer laminated on the first surface of the first metal layer. The method for producing a metal support for a flexible display device according to [9], further comprising the step of providing a first protective layer thereon.

[11] The flexible display device according to [10], wherein the first protective layer has a first protective layer opening, and in the etching step, a second opening is formed in the third metal layer. Method for manufacturing a metal support.

[12] Manufacturing the metal support for a flexible display device according to [10], wherein the first protective layer does not have an opening, and no opening is formed in the third metal layer in the etching step. Method.

According to the present disclosure, the radius of curvature of the bent portion of the flexible display device can be made smaller.

FIG. 1 is a perspective view showing a flexible display device according to one embodiment. FIG. 2 is a plan view showing a flexible display device according to one embodiment. FIG. 3 is a cross-sectional view (cross-sectional view taken along the line III--III in FIG. 2) showing a flexible display device (unfolded state) according to one embodiment. FIG. 4 is a sectional view showing a flexible display device (folded state) according to an embodiment. FIG. 5 is a plan view showing a metal support for a flexible display device according to one embodiment. FIG. 6 is a partial cross-sectional view (cross-sectional view taken along line VI-VI in FIG. 5) showing a metal support for a flexible display device according to one embodiment. FIGS. 7(a) to 7(c) are plan views showing metal supports for flexible display devices according to modified examples. FIGS. 8(a) to 8(d) are cross-sectional views showing a method of manufacturing a metal support for a flexible display device according to an embodiment. FIGS. 9(a) to 9(d) are cross-sectional views showing a metal support for a flexible display device according to a modified example.

Embodiments of the present disclosure will be described with reference to FIGS. 1 to 9. In each of the following figures, the same parts are given the same reference numerals, and some detailed explanations may be omitted.

In this specification, the first direction D1 refers to a direction located on a plane parallel to the main surface of the flexible display metal support 10 or the flexible display 70 and perpendicular to the bending center line FL. . The second direction D2 is a direction located on a plane parallel to the main surface of the flexible display metal support 10 or the flexible display 70 and parallel to the bending center line FL. Note that the first direction D1 and the second direction D2 may be directions parallel to each side of the flexible display metal support 10 or the flexible display 70, respectively. Further, the first direction D1 and the second direction D2 are orthogonal to each other. Further, the third direction D3 is a direction perpendicular to both the first direction D1 and the second direction D2, and is a direction parallel to the thickness direction of the metal support 10 for a flexible display device or the flexible display device 70. .

(Configuration of metal support for flexible display device)
First, the outline of the flexible display device according to this embodiment will be explained with reference to FIGS. 1 to 4. 1 to 4 are diagrams showing a flexible display device according to this embodiment.

The flexible display device 70 shown in FIGS. 1 and 2 may be, for example, an organic EL display device. The flexible display device 70 is flexible and has a bendable structure. That is, the flexible display device 70 can take a folded state (see FIG. 4) and an unfolded state (see FIGS. 2 and 3). The folded state is a state in which the flexible display device 70 is bent about the bending center line FL. In the folded state, the outer surfaces of the display member 71 are bent in a direction toward each other. Note that the present invention is not limited to this, and the outer surfaces of the housing 78 may be bent in a direction in which they approach each other. The unfolded state is a state in which the flexible display device 70 is opened without being bent. In the unfolded state, the entire surface of the display member 71 is located substantially on the same plane. Such a flexible display device 70 may be a thin electronic device having a portion for displaying an image. Such an electronic device may be, for example, a mobile terminal device such as a smartphone or a tablet.

As shown in FIG. 3, the flexible display device 70 includes a display member 71 and a metal support 10 for a flexible display device (hereinafter also simply referred to as metal support 10) that supports the display member 71. A buffer layer 76 such as a cushion sheet is provided between the display member 71 and the metal support 10. Further, a heat dissipation layer 77 is disposed on the surface of the metal support 10 opposite to the display member 71. Further, the display member 71, the buffer layer 76, the metal support 10, and the heat dissipation layer 77 are supported by a housing 78.

The display member 71 includes a support base material 72, a thin film transistor (TFT) 73, an organic EL element 74, and a sealing resin 75. Thin film transistor 73 is placed on support base material 72 . Organic EL element 74 is arranged on thin film transistor 73. The sealing resin 75 is placed on the organic EL element 74.

The support base material 72 supports the entire display member 71, and may be a flexible film. As the support base material 72, a synthetic resin material such as polyethylene terephthalate may be used, for example. The thin film transistor 73 is for driving the organic EL element 74 and controls the voltage applied to the electrode of the organic EL element 74. The organic EL element 74 displays images and the like by emitting light itself. Organic EL element 74 is electrically connected to thin film transistor 73. The organic EL element 74 may also be referred to as a light emitting section. The organic EL element 74 may include a reflective electrode (not shown), an organic light emitting layer, and a transparent electrode. The sealing resin 75 is for sealing the organic EL element 74 and protecting the organic EL element 74. The display member 71 is not limited to an organic EL display device. For example, the display member 71 may be another display device that itself has the function of emitting light. The display member 71 may be a micro LED display device including micro LED elements (light emitters).

The buffer layer 76 is a layer that relieves stress applied to the display member 71 when the flexible display device 70 is bent. The buffer layer 76 may be a layer of an elastic resin material such as silicone resin, polyurethane resin, or epoxy resin. The metal support 10 is a member that increases the bending strength when the flexible display device 70 is bent. Note that the configuration of the metal support 10 will be described later.

The heat dissipation layer 77 is a layer for dissipating heat from the display member 71 to the outside. The heat dissipation layer 77 may be a metal layer such as copper or nickel. Moreover, the heat dissipation layer 77 may be a plating layer produced by electrolytic plating. The housing 78 accommodates and protects the display member 71, the buffer layer 76, the metal support 10, and the heat dissipation layer 77. The housing 78 has a structure that can be bent around the bending center line FL.

The flexible display device 70 has a bending area BA and a non-bending area NA. The bending area BA is an area that physically deforms when the flexible display device 70 takes a bending state (see FIG. 4). The bending center line FL is located approximately at the center of the bending area BA. The non-bending area NA is an area that does not substantially deform when the flexible display device 70 assumes a bent state (see FIG. 4). In the first direction D1, non-bending areas NA exist on both sides of the bending area BA. The lengths of the two non-bending areas NA along the first direction D1 may be substantially the same. The present invention is not limited to this, and the lengths of the two non-bending areas NA along the first direction D1 may be different from each other. Further, the bending area BA exists at the center of the flexible display device 70 in the first direction D1. However, the bending area BA may be located at a position other than the center of the flexible display device 70 in the first direction D1.

(Configuration of metal support for flexible display device)
Next, the outline of the metal support for a flexible display device according to this embodiment will be explained with reference to FIGS. 5 and 6. 5 and 6 are diagrams showing a metal support for a flexible display device according to this embodiment.

As shown in FIGS. 5 and 6, the metal support 10 includes a first metal layer 20, a second metal layer 30, and a third metal layer 40. That is, the metal support 10 consists of a three-layer laminate. The first metal layer 20 has a first surface 20a and a second surface 20b. The first surface 20a is a surface of the flexible display device 70 facing the display member 71 side. The second surface 20b is a surface facing the heat dissipation layer 77 side of the flexible display device 70. The first surface 20a and the second surface 20b are parallel to a plane formed by the first direction D1 axis and the second direction D2 axis, respectively. The second metal layer 30 is arranged on the second surface 20b of the first metal layer 20. The third metal layer 40 is laminated on the first surface 20a of the first metal layer 20. The main metal material forming the first metal layer 20 and the main metal material forming the second metal layer 30 are different from each other. The second metal layer 30 has a first opening 31 that opens toward the opposite side of the first metal layer 20 .

The metal support 10 has a bent area BA and a non-bent area NA. The bending area BA is an area that physically deforms when the flexible display device 70 takes a bending state (see FIG. 4). The bending center line FL is located approximately at the center of the bending area BA. The non-bending area NA is an area that does not substantially deform when the flexible display device 70 assumes a bent state (see FIG. 4). The bending area BA and the non-bending area NA correspond to the bending area BA and the non-bending area NA of the above-described flexible display device 70, respectively.

The first metal layer 20 is a member that increases the bending strength when the flexible display device 70 is bent. Further, the first metal layer 20 holds the second metal layer 30 and the third metal layer 40. The first metal layer 20 has a rectangular shape in plan view. A pair of long sides of this rectangle are parallel to the first direction D1, and a pair of short sides are parallel to the second direction D2. Note that the present invention is not limited to this, and the pair of short sides may be parallel to the first direction D1, and the pair of long sides may be parallel to the second direction D2. Each corner of the rectangle may be rounded. Further, the first metal layer 20 may be square, polygonal, or circular in plan view. The planar shape of the first metal layer 20 may correspond to the planar shape of the flexible display device 70. In this case, the planar shape of the first metal layer 20 may be the same as the planar shape of the flexible display device 70. Alternatively, the planar shape of the first metal layer 20 may be smaller than the planar shape of the flexible display device 70.

The first metal layer 20 has the shape of a flexible and bendable thin plate. In addition, in this specification, "flexible" refers to "being able to bend the radius of curvature to at least 5.0 mm or less, preferably 3.0 mm or less."

The thickness T1 of the first metal layer 20 may be 10 μm or more, or 15 μm or more. By setting the thickness T1 of the first metal layer 20 to 10 μm or more, the bending strength of the first metal layer 20 can be maintained. The thickness T1 of the first metal layer 20 may be 40 μm or less, or 30 μm or less. By setting the thickness T1 of the first metal layer 20 to 40 μm or less, it is possible to prevent the flexible display device 70 incorporating the metal support 10 from becoming excessively thick.

The first metal layer 20 is made of metal. The first metal layer 20 includes a main metal material. As the main metal material of the first metal layer 20, an iron alloy such as stainless steel may be used. When stainless steel is used as the main metal material of the first metal layer 20, the first metal layer 20 has good spring properties, so the first metal layer 20 can be easily bent. In this specification, the term "main metal material" refers to a metal material that is contained in a certain member in an amount of more than 50% by mass, preferably more than 80% by mass.

The second metal layer 30 is laminated on the second surface 20b of the first metal layer 20. The second metal layer 30 is bonded to the first metal layer 20. The second metal layer 30 may be laminated on the first metal layer 20 by bonding by rolling, diffusion bonding, or depositing metal by plating, as will be described later. The second metal layer 30 increases the strength of the metal support 10. The second metal layer 30 is provided at least in the bending area BA of the first metal layer 20. The second metal layer 30 may be provided on the entire second surface 20b of the first metal layer 20, including the bending area BA, or may be provided on a part of the second surface 20b of the first metal layer 20. good. Further, the second metal layer 30 may be directly laminated on the second surface 20b of the first metal layer 20, or may be laminated on the first metal layer 20 via another layer. The thickness T2 of the second metal layer 30 may be 100 μm or less, or 50 μm or less. The thickness T2 of the second metal layer 30 may be thinner than the thickness T1 of the first metal layer 20.

The second metal layer 30 has a first opening 31 that opens toward the opposite side of the first metal layer 20 . In this case, the first opening 31 is a through opening that penetrates the second metal layer 30 in the thickness direction. That is, a portion of the second surface 20b of the first metal layer 20 is exposed to the outside through the first opening 31. The first opening 31 may be a non-penetrating opening that does not penetrate the second metal layer 30 in the thickness direction, as long as it is opened toward the opposite side of the first metal layer 20. As shown in FIG. 5, the outer periphery of the first opening 31 does not necessarily have to be formed in an annular shape. That is, the first opening 31 may reach the outer edge of the second metal layer 30.

The second metal layer 30 has a first patterned portion 32 around the first opening 31 . The first pattern shaped portion 32 is provided at a position corresponding to the bending area BA. The first pattern-shaped portion 32 includes a first island-shaped portion 33 that is an island-shaped portion. The first pattern-shaped portion 32 has a first opening 31 and a plurality of first island portions 33 each having an annular outer periphery. A first opening 31 is formed around the first island portion 33 . The first opening 31 surrounds the entire outer periphery of each first island portion 33 . The first island portions 33 are arranged at intervals in each of the first direction D1 and the second direction D2. The plurality of first island portions 33 are aligned in both the first direction D1 and the second direction D2. That is, the plurality of first island portions 33 are arranged at intervals from each other along the first direction D1, and are arranged at intervals from each other along the second direction D2. The interval P1 between the first island portions 33 in the first direction D1 may be 5 μm or more, or may be 10 μm or more. The interval P1 between the first island portions 33 in the first direction D1 may be 500 μm or less, or 100 μm or less. The interval P2 between the first island portions 33 in the second direction D2 may be 5 μm or more, or 10 μm or more. The distance P2 between the first island portions 33 in the second direction D2 may be 500 μm or less, or 100 μm or less.

Each first island portion 33 has a substantially square shape in plan view. However, the present invention is not limited to this, and each first island portion 33 may have, for example, a polygonal shape or a circular shape in plan view. The length L1 of the first island portion 33 along the first direction D1 may be 5 μm or more, or may be 10 μm or more. The length L1 of the first island portion 33 along the first direction D1 may be 500 μm or less, or 100 μm or less. The length L2 of the first island portion 33 along the second direction D2 may be 5 μm or more, or 10 μm or more. The length L2 of the first island portion 33 along the second direction D2 may be 500 μm or less, or 100 μm or less.

Further, the second metal layer 30 has a pair of first peripheral portions 34 . The first peripheral portions 34 are provided at positions corresponding to the non-bending areas NA, respectively. The first pattern-shaped portion 32 is located between the pair of first peripheral portions 34 . Although no opening is provided in the first peripheral portion 34, an opening may be present in the first peripheral portion 34.

The second metal layer 30 is made of metal. The second metal layer 30 includes a main metal material. The main metal material of the second metal layer 30 is different from the main metal material of the first metal layer 20. The main metal material of the second metal layer 30 may be, for example, copper (Cu), nickel (Ni), or an alloy thereof. When copper is used as the main metal material of the second metal layer 30, the workability of the second metal layer 30 is good, so that microfabrication is possible. Further, the thermal conductivity of the second metal layer 30 can be improved. When nickel is used as the main metal material of the second metal layer 30, the second metal layer 30 has a high surface hardness, so that it can withstand shocks when the flexible display device 70 is used.

The third metal layer 40 is laminated on the first surface 20a of the first metal layer 20. The third metal layer 40 is bonded to the first metal layer 20. The third metal layer 40 may be laminated on the first metal layer 20 by bonding by rolling, diffusion bonding, or depositing metal by plating, as will be described later. The third metal layer 40 increases the strength of the metal support 10. The third metal layer 40 is provided at least in the bending area BA of the first metal layer 20. The third metal layer 40 may be provided on the entire first surface 20a of the first metal layer 20, including the bending area BA, or may be provided on a part of the first surface 20a of the first metal layer 20. good. Further, the third metal layer 40 may be directly laminated on the first surface 20a of the first metal layer 20, or may be laminated on the first metal layer 20 via another layer. The thickness T3 of the third metal layer 40 may be 100 μm or less, or 50 μm or less. The thickness T3 of the third metal layer 40 may be thinner than the thickness T1 of the first metal layer 20. The thickness T3 of the third metal layer 40 may be the same as the thickness T2 of the second metal layer 30. Alternatively, the thickness T3 of the third metal layer 40 may be different from the thickness T2 of the second metal layer 30.

The third metal layer 40 has a second opening 41 that opens toward the opposite side of the first metal layer 20. In this case, the second opening 41 is a through opening that penetrates the third metal layer 40 in the thickness direction. That is, a portion of the first surface 20a of the first metal layer 20 is exposed to the outside through the second opening 41. The second opening 41 may be a non-penetrating opening that does not penetrate the third metal layer 40 in the thickness direction, as long as it is opened toward the opposite side of the first metal layer 20 . As shown in FIG. 5, the outer periphery of the second opening 41 does not necessarily have to be formed in an annular shape. That is, the second opening 41 may reach the outer edge of the third metal layer 40. In the example shown in FIGS. 5 and 6, the second opening 41 has the same planar shape as the first opening 31. In the example shown in FIGS. That is, the entire first opening 31 and the entire second opening 41 overlap in plan view. Note that the present invention is not limited to this, and at least a portion of the first opening 31 and at least a portion of the second opening 41 may overlap in plan view.

The third metal layer 40 has a second patterned portion 42 around the second opening 41 . The second pattern shaped portion 42 is provided at a position corresponding to the bending area BA. The second pattern-shaped portion 42 includes a second island-shaped portion 43 that is an island-shaped portion. The second pattern-shaped portion 42 has a second opening 41 and a plurality of second island portions 43 each having an annular outer periphery. A second opening 41 is formed around the second island portion 43 . The second opening 41 surrounds the entire outer periphery of each second island portion 43 . The second island-shaped portions 43 are arranged at intervals in each of the first direction D1 and the second direction D2. Note that in the examples shown in FIGS. 5 and 6, the plurality of second island portions 43 have the same planar shape as the plurality of first island portions 33. That is, the positions and shapes of the first opening 31 and the first island-shaped portion 33 are the same as the positions and shapes of the second opening 41 and the second island-shaped portion 43. Note that the present invention is not limited to this, and the positions or shapes of the first opening 31 and the first island portion 33 may be different from the positions or shapes of the second opening 41 and the second island portion 43.

Further, the third metal layer 40 has a pair of second peripheral portions 44 . The second peripheral portions 44 are provided at positions corresponding to the non-bending areas NA, respectively. The second pattern-shaped portion 42 is located between the pair of second peripheral portions 44 . Although no opening is provided in the second peripheral portion 44, an opening may be present in the second peripheral portion 44.

The third metal layer 40 is made of metal. Third metal layer 40 includes a main metal material. The main metal material of the third metal layer 40 is different from the main metal material of the first metal layer 20. The main metal material of the third metal layer 40 may be, for example, copper (Cu), nickel (Ni), or an alloy thereof. When copper is used as the main metal material of the third metal layer 40, the workability of the third metal layer 40 is good, and thus microfabrication is possible. Further, the thermal conductivity of the third metal layer 40 can be improved. When nickel is used as the main metal material of the third metal layer 40, the third metal layer 40 has a high surface hardness, so that it can withstand shocks when the flexible display device 70 is used. The main metal material of the third metal layer 40 may be the same as the main metal material of the second metal layer 30, or may be different from the main metal material of the second metal layer 30.

FIGS. 7(a) to 7(c) are plan views showing modified examples of the metal support 10, respectively. As shown in FIG. 7A, the first pattern portion 32 includes a plurality of first island portions 33 formed in an island shape, and the plurality of first island portions 33 are staggered (staggered). It may be placed in In this case, the first island portions 33 of the first row R1 are arranged at intervals along the second direction D2, and the first island portions 33 are arranged at intervals from each other along the second direction D2. and the first island-like portions 33 of the second row R2 spaced apart from each other. The first island portion 33 of the first row R1 and the first island portion 33 of the second row R2 are arranged offset in the second direction D2. In this case, since the plurality of first island portions 33 are arranged alternately, it is possible to suppress concentration of stress in a specific location when the flexible display device 70 is bent. In the example shown in FIG. 7A, the third metal layer 40 has the same planar shape as the second metal layer 30. In the example shown in FIG. Note that the present invention is not limited to this, and the third metal layer 40 may have a planar shape different from that of the second metal layer 30.

As shown in FIG. 7(b), the first pattern-shaped portion 32 may include a first linear portion that is a portion formed in a linear shape. The first pattern-shaped portion 32 has a plurality of first line-shaped portions in a region surrounded by the imaginary line in FIG. 7(b). In this case, the plurality of first line portions are arranged at intervals in the first direction D1. Each first linear portion extends linearly along the second direction D2. This increases the area in which the plurality of first line-shaped portions cover the first metal layer 20, so that the bending strength when bending the flexible display device 70 can be increased. Note that each first linear portion may extend linearly along the first direction D1. Further, the second pattern-shaped portion 42 of the third metal layer 40 has a plurality of second line-shaped portions 45 . In the example shown in FIG. 7(b), the third metal layer 40 has the same planar shape as the second metal layer 30. Note that the present invention is not limited to this, and the third metal layer 40 may have a planar shape different from that of the second metal layer 30.

As shown in FIG. 7(c), the first pattern-shaped portion 32 may include a first mesh portion 36 that is a portion formed in a mesh shape. In this case, the first mesh portion 36 may be composed of one member. The first mesh portion 36 includes a first direction portion 36a extending in the first direction and a second direction portion 36b extending in the second direction. The first opening 31 is formed so as to be surrounded by the first direction portion 36a and the second direction portion 36b. The plurality of first openings 31 are arranged such that the first openings 31 in the first row R1 are arranged at intervals from each other along the second direction D2, and the first openings 31 are arranged at intervals from each other along the second direction D2. and the first openings 31 of the second row R2. The first openings 31 in the first row R1 and the first openings 31 in the second row R2 are arranged offset in the second direction D2. That is, the center points of each first opening 31 are arranged in a rhombic grid pattern. In this case, since the area where the second metal layer 30 covers the first metal layer 20 increases, the bending strength when bending the flexible display device 70 can be increased. Furthermore, since the plurality of first openings 31 are arranged alternately, concentration of stress on a specific location when the flexible display device 70 is bent can be alleviated. Note that the center points of each first opening 31 may be arranged in a square lattice shape or a rectangular lattice shape. Further, the second pattern shaped portion 42 of the third metal layer 40 has a second mesh portion 46 formed in a mesh shape. In the example shown in FIG. 7C, the third metal layer 40 has the same planar shape as the second metal layer 30. Note that the present invention is not limited to this, and the third metal layer 40 may have a planar shape different from that of the second metal layer 30.

(Method for manufacturing metal support for flexible display device)
Next, a method for manufacturing the metal support 10 shown in FIGS. 5 and 6 will be explained using FIGS. 8(a) to 8(d).

First, as shown in FIG. 8A, a laminate 60 including a first metal layer 20, a second metal layer 30A, and a third metal layer 40A is prepared. The second metal layer 30A is in a state before the opening is formed, and is laminated on the second surface 20b of the first metal layer 20. Similarly, the third metal layer 40A is in a state before the opening is formed and is laminated on the first surface 20a of the first metal layer 20.

Any method may be used to produce the laminate 60. For example, the laminate 60 may be a clad material. In this case, the laminate 60 may be produced by rolling the first metal layer 20, the second metal layer 30A, and the third metal layer 40A with pressure and joining them. Alternatively, the laminate 60 may be produced by diffusion bonding the first metal layer 20, the second metal layer 30A, and the third metal layer 40A. Alternatively, the laminate 60 may be produced by forming the second metal layer 30A and the third metal layer 40A on the first metal layer 20, respectively, by plating.

Next, as shown in FIG. 8(b), a first protective layer 51 and a second protective layer 52 are provided on the laminate 60. Specifically, a first protective layer 51 having a first protective layer opening 51a is provided on the second metal layer 30A, and a second protective layer 52 having a second protective layer opening 52a is provided on the third metal layer 40A. . The first protective layer 51 and the second protective layer 52 may each be a resist layer. At this time, first, a photosensitive resist is applied to the entire second metal layer 30A and third metal layer 40A, respectively, and dried. Subsequently, the photosensitive resists on the second metal layer 30A and the third metal layer 40A are exposed to light through a photomask and developed. As a result, the first protective layer 51 having the first protective layer opening 51a is formed on the second metal layer 30A, and the second protective layer 52 having the second protective layer opening 52a is formed on the second surface 20b. The planar shape of the first protective layer opening 51 a corresponds to the planar shape of the first opening 31 . The planar shape of the second protective layer opening 52 a corresponds to the planar shape of the second opening 41 .

Next, as shown in FIG. 8C, the second metal layer 30A is etched with an etching solution using the first protective layer 51 as a corrosion-resistant film. Similarly, the third metal layer 40A is etched using an etching solution using the second protective layer 52 as a corrosion-resistant film. Note that the corrosive liquid can be appropriately selected depending on the materials of the second metal layer 30A and the third metal layer 40A. For example, when copper is used as the second metal layer 30A and the third metal layer 40A, spray etching may be performed on the second metal layer 30A and the third metal layer 40A using a ferric chloride aqueous solution as the etchant. good. As a result, a first opening 31 that penetrates the second metal layer 30A is formed in the second metal layer 30A. Similarly, a second opening 41 penetrating the third metal layer 40A is formed in the third metal layer 40A. Note that the main metal material of the first metal layer 20 and the main metal materials of the second metal layer 30A and the third metal layer 40A are different from each other. Therefore, the first metal layer 20 is not etched.

Thereafter, as shown in FIG. 8D, the first protective layer 51 on the second metal layer 30 and the second protective layer 52 on the third metal layer 40 are peeled off and removed. In this way, the metal support 10 shown in FIGS. 5 and 6 is obtained.

As described above, according to the present embodiment, the metal support 10 includes the first metal layer 20 and the second metal layer 30, and the second metal layer 30 has the first opening 31. Thereby, when the metal support body 10 is assembled into the flexible display device 70, the flexibility of the bending area BA of the flexible display device 70 can be improved. As a result, the shape of the bending area BA when the flexible display device 70 is folded can be made smaller. That is, the radius of curvature of the bending area BA can be made smaller.

Further, according to the present embodiment, the strength of the metal support 10 is increased by laminating the second metal layer 30 on the first metal layer 20. Furthermore, heat dissipation from the second metal layer 30 is improved.

Further, according to this embodiment, the third metal layer 40 is laminated on the first surface 20a of the first metal layer 20. In this way, by evenly sandwiching the first metal layer 20 between the second metal layer 30 and the third metal layer 40, it is possible to suppress warping of the metal support 10 before being incorporated into the flexible display device 70. Note that the metal support 10 may be composed of four or more metal layers.

Further, according to this embodiment, the third metal layer 40 has the second opening 41. Thereby, when the metal support body 10 is assembled into the flexible display device 70, the flexibility of the bending area BA of the flexible display device 70 can be improved.

Further, according to the present embodiment, the second metal layer 30 has a portion formed in an island shape, a line shape, or a mesh shape. In this case, a space (first opening 31) is formed between the first island portions 33, between the first line portions, or inside the first mesh portion 36. Thereby, as compared to the case where the entire bending area BA of the metal support 10 is covered with metal, it is possible to suppress a decrease in the flexibility of the metal support 10 in the bending area BA.

(Modified example)
Next, modifications of the metal support 10 will be described with reference to FIGS. 9(a) to 9(d). 9(a) to 9(d) are cross-sectional views showing modified examples of the metal support 10, respectively. In FIGS. 9(a) to 9(d), parts that are the same as those shown in FIGS. 1 to 8 are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 9A, the first opening 31 of the second metal layer 30 and the second opening 41 of the third metal layer 40 may be formed to be offset in plan view. In this case, the entire first opening 31 and the entire second opening 41 are arranged so as not to overlap in plan view. The overlap width δa between the metal portion of the first pattern-shaped portion 32 and the metal portion of the second pattern-shaped portion 42 may be set to 1 μm or more and 50 μm or less. As described above, since the first opening 31 and the second opening 41 are formed to be shifted from each other in plan view, the first metal layer 20 has a difference between the second metal layer 30 and the third metal layer 40. There are no parts that are not covered by both. For this reason, when the flexible display device 70 is bent, it is possible to suppress concentration of stress on a specific location of the first metal layer 20.

As shown in FIG. 9B, the first opening 31 of the second metal layer 30 and the second opening 41 of the third metal layer 40 may be formed to be offset in plan view. In this case, a portion of the first opening 31 and a portion of the second opening 41 are arranged so as to overlap in plan view. The overlapping width δb between the first opening 31 and the second opening 41 may be greater than or equal to 1 μm and less than or equal to 50 μm. Thereby, when the flexible display device 70 is bent, the flexibility in the bending region BA of the metal support body 10 can be improved while suppressing concentration of stress on a specific location of the first metal layer 20.

As shown in FIG. 9(c), the third metal layer 40 does not need to have the second opening 41. The third metal layer 40 spreads without gaps over at least the entire bending area BA. The third metal layer 40 may spread over the entire first surface 20a without any gaps. Since the third metal layer 40 does not have an opening, the third metal layer 40 side of the metal support 10 can be flattened, and the display member 71 can be attached to a flatter surface of the metal support 10.

When manufacturing the metal support 10 shown in FIG. 9(c), in the step of providing the first protective layer 51 and the second protective layer 52 on the laminate 60 described above (see FIG. 8(b)), the second protective layer 51 and the second protective layer 52 are A layer 52 that does not have an opening (second protective layer opening 52a) is used. Thereby, it is possible to prevent an opening from being formed in the third metal layer 40A during the etching described above (see FIG. 8(c)).

As shown in FIG. 9(d), the metal support 10 does not need to have the third metal layer 40. In this case, the metal support 10 includes a first metal layer 20 and a second metal layer 30. That is, the metal support 10 consists of a two-layer laminate. The entire first surface 20a of the first metal layer 20 is exposed to the outside. Since the metal support 10 does not have the third metal layer 40, the first surface 20a side of the metal support 10 can be flattened, and the display member 71 can be attached to a flatter surface of the metal support 10. . Further, the metal support 10 can be made thin.

When producing the metal support 10 shown in FIG. 9(d), in the step of providing the first protective layer 51 and the second protective layer 52 on the laminate 60 described above (see FIG. 8(b)), the third metal No second protective layer 52 is provided on layer 40A. As a result, the entire third metal layer 40A is etched away during the above-described etching (see FIG. 8(c)). Alternatively, as the above-mentioned laminate 60, a laminate consisting of two layers, the first metal layer 20 and the second metal layer 30A, may be used (see FIG. 8(a)). Thereby, a two-layer metal support 10 including the first metal layer 20 and the second metal layer 30 is obtained.

It is also possible to combine the plurality of components disclosed in each of the above embodiments and modifications as appropriate. Alternatively, some components may be deleted from all the components shown in the above embodiments and modifications.

10 Metal support for flexible display device 20 First metal layer 20a First surface 20b Second surface 30 Second metal layer 31 First opening 32 First pattern shaped portion 33 First island portion 34 First peripheral portion 40 3 metal layer 41 second opening 42 second pattern-shaped portion 43 second island-shaped portion 44 second peripheral portion 70 flexible display device

Claims (12)

In a metal support for a flexible display device,
a first metal layer having a first surface and a second surface;
a second metal layer laminated on the second surface of the first metal layer,
The main metal material constituting the first metal layer and the main metal material constituting the second metal layer are different from each other,
A metal support for a flexible display device, wherein the second metal layer has a first opening. The metal support for a flexible display device according to claim 1, further comprising a third metal layer laminated on the first surface of the first metal layer. The metal support for a flexible display device according to claim 2, wherein the third metal layer has a second opening. 4. The metal for a flexible display device according to claim 3, wherein at least a portion of the first opening of the second metal layer and at least a portion of the second opening of the third metal layer overlap in plan view. support. The flexible display device according to claim 3, wherein at least a portion of the first opening of the second metal layer and at least a portion of the second opening of the third metal layer are offset in plan view. Metal support for. The metal support for a flexible display device according to claim 3, wherein the third metal layer does not have an opening. The flexible flexible film according to claim 1, wherein the second metal layer has a patterned portion around the first opening, and the patterned portion includes a portion formed in an island shape, a line shape, or a mesh shape. Metal support for display devices. A display member,
A flexible display device comprising: the metal support for a flexible display device according to claim 1, which supports the display member. In a method for manufacturing a metal support for a flexible display device,
a first metal layer having a first surface and a second surface; a second metal layer laminated on the second surface of the first metal layer; preparing a laminate in which the metal material and the main metal material constituting the second metal layer are different from each other;
providing a second protective layer having a second protective layer opening on the second metal layer of the laminate;
A method for manufacturing a metal support for a flexible display device, comprising: etching the second metal layer of the laminate to form a first opening in the second metal layer. The laminate further includes a third metal layer stacked on the first surface of the first metal layer,
The method for manufacturing the metal support for a flexible display device includes:
The method for manufacturing a metal support for a flexible display device according to claim 9, further comprising the step of providing a first protective layer on the third metal layer. the first protective layer has a first protective layer opening;
The method for manufacturing a metal support for a flexible display device according to claim 10, wherein in the etching step, a second opening is formed in the third metal layer. The first protective layer has no openings,
11. The method for manufacturing a metal support for a flexible display device according to claim 10, wherein in the etching step, no opening is formed in the third metal layer.

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