WO2020111582A1

WO2020111582A1 - Transparent display unit and glass assembly comprising the same

Info

Publication number: WO2020111582A1
Application number: PCT/KR2019/015356
Authority: WO
Inventors: Kangmin KIM
Original assignee: Hankuk Glass Industries Inc
Current assignee: Hankuk Glass Industries Inc
Priority date: 2018-11-27
Filing date: 2019-11-12
Publication date: 2020-06-04
Anticipated expiration: 2021-05-27
Also published as: KR20200062702A

Abstract

A transparent display unit according to an exemplary embodiment of the present invention includes: a transparent substrate film; an edge electrode layer disposed on the upper surface of the transparent substrate film; an anisotropically conductive adhesive layer disposed on the edge electrode layer; and a flexible printed circuit board (FPCB) disposed on the anisotropically conductive adhesive layer and electrically connected to the edge electrode layer through the anisotropically conductive adhesive layer, wherein the flexible printed circuit board (FPCB) includes an electrode portion and a resin layer, and the resin layer extends from the edge portion of the anisotropically conductive adhesive layer to be in contact with the edge electrode layer.

Description

TRANSPARENT DISPLAY UNIT AND GLASS ASSEMBLY COMPRISING THE SAME

The present invention relates to a transparent display unit and a glass assembly. Specifically, the present invention relates to a transparent display unit and a glass assembly capable of displaying characters or images while maintaining visual transparency. More specifically, the present invention relates to a transparent display and a glass assembly for preventing corrosion of an edge electrode layer generated due to contact of a sealing member and an anisotropically conductive adhesive layer.

In general, a glass window serves to allow external light to be introduced indoors, to perform appropriate ventilation of indoor air by blocking and introducing external air, and to maintain cooling and heating efficiency by blocking heat flow between indoors and outdoors in a closed state.

In recent years, a window made of a light emitting diode (LED) electro-optical glass assembly to which LEDs are inserted has been used as a glass window of a building. The window made of an LED electro-optical glass assembly may exhibit an illumination effect and an advertising effect without impairing an intrinsic function of a glass window. However, the LED electro-optical glass assembly has the LEDs inserted between two glass sheets, and the LEDs are mounted on an electrode layer formed on a glass sheet. In addition, a space between the glass sheets is sealed by a sealing member so as to protect the LEDs.

On the other hand, a flexible printed circuit board (FPCB) for electrically connecting the electrode layer and the driver controller is formed at the edge portion of the electrode layer of the glass assembly. Here, the driving controller controls the driving of the LED to display a character or an image.

A transparent display unit and a glass assembly are provided.

Specifically, a transparent display unit and a glass assembly capable of displaying characters or images while maintaining visual transparency are provided. More specifically, the transparent display and the glass assembly for preventing corrosion of an edge electrode layer generated due to a contact of a sealing member and an anisotropically conductive adhesive layer are provided.

A transparent display unit according to an exemplary embodiment of the present invention includes: a transparent substrate film; an edge electrode layer disposed on the upper surface of the transparent substrate film; an anisotropically conductive adhesive layer disposed on the edge electrode layer; and a flexible printed circuit board (FPCB) disposed on the anisotropically conductive adhesive layer and electrically connected to the edge electrode layer through the anisotropically conductive adhesive layer.

The flexible printed circuit board (FPCB) includes an electrode portion and a resin layer, and the resin layer extends from the edge portion of the anisotropically conductive adhesive layer to be in contact with the edge electrode layer.

A driving controller controlling driving of the transparent display unit may be further included, and the flexible printed circuit board (FPCB) may electrically connect the edge electrode layer and the driving controller.

A ratio W/L of an entire width W of one or a plurality of flexible printed circuit board (FPCB) for the edge portion length L of the transparent substrate film may be 0.1 to 0.5.

The thickness of the transparent substrate film may be 200 to 300 μm.

The edge electrode layer may include a circuit pattern formed of one or more of a metal, a metallic nanowire, a transparent conductive oxide, a metal mesh, a carbon nanotube, and graphene.

The anisotropically conductive adhesive layer may include a resin and conductive particles dispersed in the resin.

The anisotropically conductive adhesive layer may have the thickness of 25 μm to 225 μm.

The resin layer may include one or more of a polyimide resin and a poly ester resin.

The flexible printed circuit board (FPCB) may have the thickness of 25 μm to 225 μm.

The length of the resin layer extending from the edge portion of the anisotropically conductive adhesive layer may be 1 mm or more.

A glass assembly according to an exemplary embodiment of the present invention includes: a transparent substrate film; an edge electrode layer disposed on the upper surface of the transparent substrate film; an anisotropically conductive adhesive layer disposed on the edge electrode layer; a flexible printed circuit board (FPCB) disposed on the anisotropically conductive adhesive layer and electrically connected to the edge electrode layer through the anisotropically conductive adhesive layer; a first sealing member disposed on the flexible printed circuit board (FPCB); and a first glass sheet disposed on the first sealing member,

A second sealing member disposed on the lower surface of the transparent substrate film, and a second glass sheet disposed on the lower surface of the second sealing member, may be further included.

The first sealing member may include one or more among polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), an ionoplast polymer, a cyclo olefin polymer (COP), and polyurethane.

The second sealing member may include one or more among polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), an ionoplast polymer, a cyclo olefin polymer (COP), and polyurethane.

The transparent display unit and the glass assembly according to an exemplary embodiment of the present invention may display the characters or the images while maintaining the visual transparency. For this reason, the transparent display unit and the glass assembly according to the exemplary embodiment of the present invention are applied to an exterior window of a building or a windshield of a vehicle to provide desired information to a user while maintaining the cooling and heating effect of the room to be used for lighting, an advertising means, and the like.

Also, the transparent display unit and the glass assembly according to an exemplary embodiment of the present invention are configured so that the resin layer among the flexible printed circuit board (FPCB) extends from the edge portion of the anisotropically conductive adhesive layer to be in contact with the edge electrode layer, thereby preventing the corrosion of the edge electrode layer generated due to the contact of the anisotropically conductive adhesive layer.

FIG. 1 is a schematic cross-sectional view illustrating a transparent display unit.

FIG. 2 is a schematic cross-sectional view illustrating a transparent display unit according to an exemplary embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view illustrating a cross-section (an a-b cross-section) of a transparent display unit according to an exemplary embodiment of the present invention.

FIG. 4 is a schematic top plan view illustrating an anisotropically conductive adhesive layer and a flexible printed circuit board (FPCB) in a transparent display unit according to an exemplary embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a case that a first sealing member is disposed on a flexible printed circuit board (FPCB) of a transparent display unit according to an exemplary embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a case that a first sealing member is disposed on a flexible printed circuit board (FPCB) of a transparent display unit according to Comparative Example 1.

FIG. 7 is a schematic cross-sectional view illustrating a plan surface of a transparent display unit according to an exemplary embodiment of the present invention.

FIG. 8 is a view schematically showing a cross-section of a glass assembly according to an exemplary embodiment of the present invention.

FIG. 9 is a photo of an edge electrode layer after estimating corrosion of Embodiment Example 1.

FIG. 10 is a photo of an edge electrode layer after estimating corrosion of Comparative Example 1.

The terms "first", "second", and "third" are used herein to explain various parts, components, regions, layers, and/or sections, but it should be understood that they are not limited thereto. These terms are used only to discriminate one portion, component, region, layer, or section from another portion, component, region, layer, or section. Thus, a first portion, component, region, layer, or section may be referred to as a second portion, component, region, layer, or section without departing from the scope of the present invention.

The technical terms used herein are to simply mention a particular embodiment and are not meant to limit the present invention. An expression used in the singular encompasses the expression of the plural, unless it has a clearly different meaning in the context. It will be further understood that the term "comprises" or "includes", used in this specification, specifies stated properties, regions, integers, steps, operations, elements, and/or components, but does not preclude the presence or addition of other properties, regions, integers, steps, operations, elements, components, and/or groups.

When referring to a part as being "on" or "above" another part, it may be positioned directly on or above another part, or another part may be interposed therebetween. In contrast, when referring to a part being "directly above" another part, no other part is interposed therebetween.

Unless defined otherwise, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms defined in commonly used dictionaries are further interpreted as having meanings consistent with the relevant technical literature and the present disclosure, and are not to be construed as idealized or very formal meanings unless defined otherwise.

The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

The present inventors provide a glass assembly capable of displaying characters or images while maintaining a visual transparency by inserting a transparent display unit in which an LED is mounted on a transparent substrate film between glass sheets.

FIG. 1 represents a cross-section of a transparent display unit 100 according to an exemplary embodiment of the present invention. As shown in FIG. 1, the transparent display unit 100 includes a transparent substrate film 10, an electrode layer disposed on an upper surface of the transparent substrate film, and a plurality of light emitting diodes (LEDs) 21 mounted on the electrode layer.

A driving controller 50 for controlling driving of the transparent display unit is disposed in the edge portion of the electrode layer. The driving controller 50 controls the driving of the transparent display unit 100, that is, controls the driving of the light emitting diodes 21 to display the characters or the images.

Also, the electrode layer is electrically connected to the driving controller 50 through a flexible printed circuit board (FPCB) 40 in the edge portion of the transparent substrate film 10. An exemplary embodiment of the present invention relates to the edge portion (a dotted line circle).

The electrode layer includes an edge electrode layer 22 connected to the flexible printed circuit board (FPCB) 40 in the edge portion, and an inner electrode layer 23 to which the light emitting diode 21 is mounted.

FIG. 2 is a schematic cross-sectional view illustrating a transparent display unit 100 according to an exemplary embodiment of the present invention. The transparent display unit 100 of FIG. 2 is merely for illustrating the present invention, and the present invention is not limited thereto. Thus, the transparent display unit 100 of FIG. 2 may be transformed into various forms.

FIG. 3 is a schematic cross-sectional view illustrating a cross-section (an a-b cross-section) of a transparent display unit 100 according to an exemplary embodiment of the present invention.

FIG. 4 is a schematic top plan view illustrating an anisotropically conductive adhesive layer 30 and a flexible printed circuit board (FPCB) 40 in a transparent display unit 100 according to an exemplary embodiment of the present invention.

As shown in FIG. 2 to FIG. 4, the transparent display unit 100 according to an exemplary embodiment of the present invention includes the transparent substrate film 10, the edge electrode layer 22 disposed on the upper surface of the transparent substrate film 10, the anisotropically conductive adhesive layer 30 disposed on the edge electrode layer 22, and the flexible printed circuit board (FPCB) 40 disposed on the anisotropically conductive adhesive layer 30 and electrically connected to the edge electrode layer 22 through the anisotropically conductive adhesive layer 30.

As shown in FIG. 2 to FIG. 4, in an exemplary embodiment of the present invention, the flexible printed circuit board (FPCB) 40 includes an electrode portion 41 and a resin layer 42, and the resin layer 42 extends from the edge portion of the anisotropically conductive adhesive layer 30 to be in contact with the edge electrode layer 22. In detail, the resin layer 42 climbs the edge portion of the anisotropically conductive adhesive layer 30, and for example, extends by 1 mm or more, thereby preventing the anisotropically conductive adhesive layer 30 from climbing the resin layer 42 and being exposed outside.

As illustrated in FIG. 6, when the resin layer 42 does not extend from the edge portion of the anisotropically conductive adhesive layer 30, if moisture penetrates into the edge electrode layer 22 through a first sealing member 61, a positive ion (for example, a Cu²⁺ ion) easily migrates to the electrode portion 41 of the flexible printed circuit board (FPCB) 40 from the edge electrode layer 22 through the edge portion of the anisotropically conductive adhesive layer 30, thereby causing the edge electrode layer 22 to be corroded.

In contrast, as shown in FIG. 5, in the exemplary embodiment of the present invention, due to the above-described form of the resin layer 42, by preventing the penetration of moisture through the first sealing member 61 and preventing the generation of the positive ions from the edge electrode layer 22, the corrosion of the edge electrode layer 22 is prevented and durability and life-span of the edge electrode layer 22 are improved.

Hereinafter, each configuration is described in detail.

In an exemplary embodiment of the present invention, the transparent substrate film 10 may be a light transmitting polymer film of a single layer or a plurality of layers. The transparent substrate film 10 may have an insulation characteristic and heat resistance to prevent a state change by external light while preventing power from being leaked to the outside. An example of the transparent substrate film 10 is polyethylene terephthalate (PET), polycarbonate (PC), a cyclo olefin polymer (COP), etc. however it is not limited thereto. For example, the transparent substrate film 10 may be a COP film. In this case, the heat resistance is excellent, and the durability of the transparent display unit 100 is improved.

The thickness of this transparent substrate film 10 is not particularly limited. However, if the thickness of the transparent substrate film 10 is very thin, during the bonding of a glass assembly 200, the transparent substrate film 10 may be deformed by a pressure applied to the LED side or a crack may be caused on the electrode layer part. On the other hand, if the thickness of the transparent substrate film is very thick, the crack may be generated in

glass sheets

71 and 72 due to the stress. According to an exemplary embodiment, the thickness of the transparent substrate film 10 may be about 200 to 300 μm. In this case, since the above-described problem does not only occur but also the heat resistance is excellent, even if the transparent display unit 100 is exposed to the external light for a long time, thermal deformation of the transparent substrate film 10 may be prevented.

In the transparent display unit 100 according to an exemplary embodiment of the present invention, the electrode layer is a portion disposed on one surface of the transparent substrate film 10, and serves to drive the light emitting diodes (LED) 21.

In addition, since the electrode layer is excellent in light transmittance, not only is the external light incident, but the portion in which the electrode layer is formed does not block the user's view, and the appearance characteristic is also excellent. Therefore, the transparent display unit 100 according to an exemplary embodiment of the present invention has excellent visual transparency.

The electrode layer includes the edge electrode layer 22 connected to the flexible printed circuit board (FPCB) 40 in the edge portion and the inner electrode layer 23 to which the light emitting diode 21 is mounted. The electrode layer may include a circuit pattern in which one or more among a metal, a metallic nanowire, a transparent conductive oxide, a metal mesh, carbon nanotubes, and a graphene is formed. In detail, the edge electrode layer 22 may include a metal line. The inner electrode layer 23 may include one or more among the metallic nanowire, the transparent conductive oxide, the metal mesh, the carbon nanotubes, and the graphene.

Here, a non-limiting example of the metallic nanowires includes a silver nanowire (an Ag nanowire), a copper nanowire, a nickel nanowire, and the like, which may be used alone or in combination of two or more thereof. A non-limiting example of the transparent conductive oxide may include indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), aluminum zinc oxide (AZO), indium oxide (In₂O₃), and the like, which may be used alone or in combination of two or more thereof. A non-limiting example of the metal mesh may include a silver (Ag) mesh, a copper (Cu) mesh, an aluminum (Al) mesh, and the like, which may be used alone or in combination of two or more thereof. Among them, the silver nanowire, the copper mesh, and the silver mesh have excellent conductivity and light transmittance, while ITO and IZO have lower low resistivity values, may be deposited at a low temperature, and have high light transmittance of visible light.

According to an exemplary embodiment, the inner electrode layer 23 may include a circuit pattern formed of the electrode material selected from a group consisting of the silver nanowire (Ag nanowire), the copper mesh, and the silver mesh. At this time, the line width and the thickness of the circuit pattern are not particularly limited. However, when the circuit pattern has a width of about 5 to 15 μm and a thickness of about 0.2 to 1 μm, the inner electrode layer 23 has sheet resistance of about 0.5 to 3 Ω/sq.

The inner electrode layer 23 may be formed through methods known in the art. For example, for the inner electrode layer 23, at least one circuit pattern may be formed by irradiating a laser or through a mask and etching process after the above-described electrode material is disposed on the transparent substrate film 10. Alternatively, the circuit pattern made of the electrode material may be formed on the transparent substrate film 10 through an inkjet printing process. However, the present invention is not limited thereto.

In the transparent display unit 100 according to an exemplary embodiment of the present invention, the light emitting diode (LED) 21 is a light emitting member that is mounted on an inner electrode layer 23 and is lit depending on the supply of a power. Since the plurality of light emitting diodes 21 are spaced apart from each other and arranged in a matrix form, the light emitting diodes 21 may display various types of characters or images, and may also display a motion picture.

The light emitting diode 21 usable in the exemplary embodiment of the present invention may be used without particular limitation as long as it is commonly known in the art. Further, the light emitting diode 21 may be a monochromatic light emitting diode 21 displaying a color such as red R, green G, or blue B, or a light emitting diode 21 displaying two colors such as R and G, or a light emitting diode 21 displaying three colors such as R, G, and B. When each light emitting diode 21 is the color light emitting diode 21 displaying three colors such as R, G, and B, characters or images with various colors may be displayed.

The light emitting diode 21 may be fixed onto the inner electrode layer 23 through mounting methods known in the art. A pad (not shown) including a material having high electrical conductivity such as silver (Ag) may be formed in at least part among the inner electrode layer 23. In this case, the light emitting diode 21 may be fixed on the pad by using a low temperature SMT (surface mount technology) process. Here, the light emitting diode 21 may be adhered to the pad through solder.

The electrode layer is divided into the inner electrode layer 23 on which the LED 21 is mounted and the edge electrode layer 22 connected to the flexible printed circuit board (FPCB) 40 without mounting the LED 21. The edge electrode layer 22 may be opaque and the inner electrode layer 23 may be transparent.

The anisotropically conductive adhesive layer 30 disposed on the electrode layer, and electrically connects the flexible printed circuit board (FPCB) 40 and the edge electrode layer 22.

The anisotropically conductive adhesive layer 30 may variously be anisotropically conductive adhesive layers 30 used in the field without limitation.

In detail, the anisotropically conductive adhesive layer 30 may include a resin and a conductivity particle dispersed in the resin. As described above, the anisotropically conductive adhesive layer 30 may be a film having electrical conductivity in the thickness direction of the adhesive layer and representing an insulation characteristic in the surface direction of the film. In addition, it is possible to use a resin that can secure the adhesion to the edge electrode layer 22 and the flexible printed circuit board (FPCB) 40.

More specifically, the resin included in the anisotropically conductive adhesive layer 30 may include at least one kind or more of acryl and epoxy.

In detail, the conductive particle included in the anisotropically conductive adhesive layer 30 may include a polymer core having an average particle diameter of 2 to 20 μm and a coating layer including one or more of Ni, Au, Cu, and Ag.

The thickness of the anisotropically conductive adhesive layer 30 may be 25 to 225 μm.

The anisotropically conductive adhesive layer 30 may be disposed so as to include at least part among the portion where the edge electrode layer 22 and the flexible printed circuit board (FPCB) 40 are overlapped.

The flexible printed circuit board (FPCB) 40 is disposed on the anisotropically conductive adhesive layer 30 and is electrically connected to the edge electrode layer 22 through the anisotropically conductive adhesive layer 30. The electrically-connected flexible printed circuit board (FPCB) 40 electrically connects the edge electrode layer 22 and the driving controller 50. The driving controller 50 controls the driving of the transparent display unit 100. That is, by controlling the driving of the light emitting diode 21, the characters or the images are displayed.

The flexible printed circuit board (FPCB) 40 may be a flexible printed circuit board (FPCB) used in the field without limitation. In detail, the flexible printed circuit board (FPCB) 40 may include the electrode portion 41 and the resin layer 42. As shown in FIG. 2, the electrode portion 41 of the flexible printed circuit board (FPCB) 40 may be disposed to correspond to the electrode portion of the edge electrode layer 22.

As described above, in an exemplary embodiment of the present invention, the flexible printed circuit board (FPCB) 40 includes the electrode portion 41 and the resin layer 42 and the resin layer 42 is configured to extend from the edge portion of the anisotropically conductive adhesive layer 30 so as to be in contact with the edge electrode layer 22, thereby preventing the corrosion of the electrode portion 41.

More specifically, a length A by which the resin layer 42 extends from the edge portion of the anisotropically conductive adhesive layer 30 may be 1 mm or more. If the length A extending from the edge portion of the anisotropically conductive adhesive layer 30 is very short, it may be difficult to appropriately obtain the corrosion protection effect of the desired electrode portion 41. The upper limit is not particularly limited, but may be 10 mm or less. Even if the length A extending from the edge portion of the anisotropically conductive adhesive layer 30 is longer than as above-described, a more effective anticorrosion effect is added, but may cause a problem in the adherence aspect of the resin layer 42 and the edge electrode layer 22. More specifically, it may be 5 mm or less. Even more specifically, it may be 3 mm or less.

The electrode portion 41 of the flexible printed circuit board (FPCB) 40 may be made of a conductive metal such as copper, tin plated copper, or nickel plated copper. As a conductor, a conductive metal of a thin shape is preferable.

As the resin layer 42 of the flexible printed circuit board (FPCB) 40, polyimide or polyester may be included.

The number of flexible printed circuits (FPCB) 40 may be one or more. However, when the flexible printed circuit board (FPCB) 40 is disposed on a large portion of the edge portion of the transparent substrate film 10, bonding reliability of the glass assembly 200 may be deteriorated. Therefore, it is preferable to adjust the width of each flexible printed circuit board (FPCB) 40 so that the ratio of the entire width W of the flexible printed circuit board (FPCB) 40 for the edge portion length L of the transparent substrate film 10 is about a 0.1 to 0.5 range. In this case, the entire width W of the flexible printed circuit board (FPCB) 40 is the sum of the width W1 of the n flexible printed circuits (FPCB) as n × W1, where the widths of the flexible printed circuits (FPCB) 40 may be equal to each other or be different. FIG. 7 briefly illustrates the relationship between the edge portion length L and the width W of the flexible printed circuit board (FPCB) 40.

FIG. 8 shows the cross-section of the glass assembly 200 according to an exemplary embodiment of the present invention. The glass assembly 200 of FIG. 8 is merely for illustrating the present invention, and the present invention is not limited thereto. Thus, the glass assembly 200 of FIG. 8 may be modified in various forms.

As shown in FIG. 8, the glass assembly 200 according to an exemplary embodiment of the present invention includes the transparent substrate film 10, the edge electrode layer 22 disposed on the upper surface of the transparent substrate film 10, the anisotropically conductive adhesive layer 30 disposed on the edge electrode layer 22, the flexible printed circuit board (FPCB) 40 disposed on the anisotropically conductive adhesive layer 30 and electrically connected to the edge electrode layer 22 through the anisotropically conductive adhesive layer 30, the first sealing member 61 disposed on the flexible printed circuit board (FPCB), and the first glass sheet 71 disposed on the first sealing member 61.

The flexible printed circuit board (FPCB) 40 includes the electrode portion 41 and the resin layer 42, and the resin layer 42 extends from the edge portion of the anisotropically conductive adhesive layer 30 to be in contact with the edge electrode layer 22.

As shown in FIG. 8, the first sealing member 61 disposed on the resin layer 42 also extends from the edge portion of the edge portion and resin layer 42 of the anisotropically conductive adhesive layer 30 to be in contact with the edge electrode layer 22.

The transparent substrate film 10, the edge electrode layer 22, the anisotropically conductive adhesive layer 30, and the flexible printed circuit board (FPCB) 40 described in the transparent display unit 100 are the same such that the repeated description is omitted.

In the glass assembly 200 according to an exemplary embodiment of the present invention, the first sealing member 61 is a part disposed between the first glass sheet 71 and the transparent display unit 100 so that the first glass sheet 71 and the transparent display unit 100 are not separated from each other. The first sealing member 61 also prevents moisture and outside air such as oxygen from penetrating the transparent display unit 100.

The first sealing member 61 may be disposed on the entire surface of the first glass sheet 71. Alternatively, although not shown, the first sealing member 61 may be disposed on the edge portion of the first glass sheet 71.

The first sealing member 61 is formed of an optically transparent polymer so that the external light may be incident without blocking the user's view. In detail, the first sealing member 61 may include one or more among polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), an ionoplast polymer, and polyurethane. For example, the first sealing member 61 is formed of a PVB resin. In this case, the first sealing member 61 may not only seal the transparent display unit 100 on the first glass sheet 71, but also block ultraviolet rays (UV) by about 99 % or more while blocking the external air.

The thickness of the first sealing member 61 is not particularly limited. However, if the thickness of the first sealing member 61 is very thick, pressure is applied to the transparent display unit 100 during the bonding process between the first glass sheet 71 and the transparent display unit 100 such that a crack may be generated in the electrode layer or light transmittance may be deteriorated. On the other hand, if the thickness of the first sealing member 61 is too thin, the sealing characteristic and the air barrier property may be deteriorated. Therefore, the thickness of the first sealing member 61 may be 0.2 to 0.8 mm.

In the glass assembly 200 according to an exemplary embodiment of the present invention, the first glass sheet 71 is a plate member including a transparent polymer such as glass and/or polymethylmethacrylate (PMMA), polycarbonate (PC), and the like, and is colorless-transparent or colored-transparent. In this case, the first glass sheet 71 may have light transmittance of about 85 % or more for visible rays.

The first glass sheet 71 may have a planar shape or a curved shape such as a bow, that is, a curved-surface shape. Here, when the first glass sheet 71 has the curved-surface shape, a curved radius R may be about 0.2 to 0.3 m.

As shown in FIG. 8, the second sealing member 62 and the second glass sheet 72 may be further included in the lower surface of the transparent substrate film 10, that is, the lower surface of the transparent display unit 100.

In the glass assembly 200 according to an exemplary embodiment of the present invention, the second sealing member 62 is a portion disposed between the second glass sheet 72 and the transparent display unit 100, and prevents moisture and the outside air such as oxygen from penetrating into the transparent display unit 100.

As shown in FIG. 8, the second sealing member 62 is disposed on the entire surface of the transparent display unit 100, thereby covering the transparent display unit 100. In this case, the second sealing member 62 seals the transparent display unit 100 and the second glass sheet 72 from being separated from each other while protecting the light emitting diode 21 of the transparent display unit 100. On the other hand, although not shown, the second sealing member 62 may be disposed on the edge portion of the second glass sheet 72. In this case, because of the second sealing member 62, a space portion is formed between the second glass sheet 72 and the transparent display unit 100.

The second sealing member 62 is formed of an optically transparent polymer so that the external light may be incident without blocking the user's view. In detail, the second sealing member 62 may include one or more among polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), an ionoplast polymer, and polyurethane. As an example, the second sealing member 62 may be formed of the PVB resin. In this case, the second sealing member 62 may not only seal the transparent display unit 100 on the second glass sheet 72, but may also block about 99 % or more of ultraviolet (UV) while locking out the external air.

The thickness of the second sealing member 62 is adjusted according to the height of the light emitting diode 21 in the transparent display unit 100. However, in order to protect the light emitting diodes 21 of the transparent display unit 100 and to not impair the light transmittance, a ratio (D₁/H₁) of the thickness D1 of the second sealing member 62 for the height H₁of the light emitting diode 21 may be in a 1.5 to 5 range.

Like the first glass sheet 71, the second glass sheet 72 is a plate member including a transparent polymer such as glass and/or polymethylmethacrylate (PMMA), polycarbonate (PC), and the like, and is colorless-transparent or colored-transparent. In this case, the second glass sheet 72 may have light transmittance of about 85 % or more for visible rays. The second glass sheet 72 may have the same or different material, color, and/or light transmittance as the first glass sheet 71.

The second glass sheet 72 may have the planar shape or the curved shape such as a bow, that is, the curved-surface shape. Here, when the second glass sheet 72 has the curved-surface shape, the curved radius R may be about 0.2 to 0.3 m.

In the glass assembly 200 according to an exemplary embodiment of the present invention, the transparent display unit 100 is a part interposed between the first glass sheet 71 and the second glass sheet 72, and displays the images and the character information. In addition, since the transparent display unit 100 has a yellowness index (YI) value of 3.0 or less, the external light may not only be incident, but also the visual transparency of the glass assembly 200 is not deteriorated and thus the user's view is not blocked.

In an exemplary embodiment of the present invention, there may be one transparent display unit 100. Also, as shown in FIG. 7, there may be multiple transparent display units 100. A plurality of transparent display units 100 may display one large image. That is, when a video signal is divided according to a predetermined screen division method in the LED driver, one large image is generated in a plurality of divided images, and then each divided image may be displayed through each corresponding transparent display unit 100.

The glass assembly 200 has light transmittance of about 70 to 80 % and light reflectance of about 8 to 15 % at a wavelength in the visible ray region (a wavelength of 400 to 700 nm). Particularly, when the glass assembly 200 according to the exemplary embodiment of the present invention has light transmittance of 70 % or more at the wavelength in the visible ray region and satisfies Equation 1 below, the visual field is not blocked by the electrode layer, perspective may be ensured inside or outside, and an appearance characteristic, electrical conductivity, and a visual transparency may also be improved.

[Equation 1]

(In Equation 1, T represents light transmittance (%) of the glass assembly in the wavelength of the visible ray region, and R_S represents sheet resistance (Ω/sq) of the electrode layer.)

According to an exemplary embodiment, the glass assembly 200 satisfies Equation 2 while having the light transmittance of 70 % or more at the wavelength of the visible ray region. In this case, since the glass assembly 200 has excellent electrical conductivity, the power consumption is low and the heat is low, and also the visual transparency is secured so that a character or an image can be displayed more clearly.

[Equation 2]

(In Equation 2, T represents the light transmittance (%) of the glass assembly in the wavelength of the visible ray region, and R_S represents the sheet resistance (Ω/sq) of the electrode layer.)

Also, in an exemplary embodiment of the present invention, the flexible printed circuit board (FPCB) 40 includes the electrode portion 41 and the resin layer 42, and the resin layer 42 extends from the edge portion of the anisotropically conductive adhesive layer 30 to be in contact with the edge electrode layer 22, thereby preventing the corrosion of the edge electrode layer 22. Specifically, in the state that the current is applied to the electrode layer and the flexible printed circuit board (FPCB) 40, when the glass assembly 200 is immersed in water at 100 ℃ for 24 hours, a corrosion rate may be 1 % or less. In this case, the corrosion rate refers to a weight of the corroded edge electrode layer 22 with respect to the entire edge electrode layer 22 weight.

Hereinafter, the present invention is described in more detail through an experimental example. However, the experimental example is merely for illustrating the present invention, and the present invention is not limited thereto.

[Example 1]

1-1. Manufacturing of a transparent display unit

On one surface of a PET film substrate (size: 500 mm×600 mm, thickness: 250 μm), a circuit pattern (line width: 15 μm) is formed with a copper mesh through a mask and etching process to form an inner electrode layer (sheet resistance: about 1 Ω/sq). The edge electrode layer forms the circuit pattern with the copper line. Next, after forming a silver (Ag) solder on the electrode layer through screen printing, a plurality of LEDs (height: about 1mm) are mounted to each silver (Ag) solder by using a low temperature SMT (surface mount technology). The anisotropically conductive adhesive layer (RA3351, manufactured by H&S company) is formed at the edge portion of the electrode layer on which the LED is not mounted, and the flexible printed circuit board (FPCB) is stacked on the anisotropically conductive adhesive layer. In this case, the transparent display unit is manufactured by stacking the resin layer of the flexible printed circuit board (FPCB) to extend 1 mm (i.e., A is 1 mm) compared with the edge portion of the anisotropically conductive adhesive layer.

1-2. Manufacturing of a glass assembly

. On a first glass sheet, after sequentially stacking the transparent display unit manufactured in Example 1-1, the PVB resin film (thickness of 1.52 mm, Kuraray Butacite), and the second glass sheet, they are combined by applying pressure of 11.5 bar at 130 ℃ to manufacture the glass assembly.

[Example 2]

Except that the resin layer of the flexible printed circuit board (FPCB) is stacked so as to extend by 1.5 mm (i.e., A is 1.5 mm) compared with the edge portion of the anisotropically conductive adhesive layer, it is performed in the same manner as in Example 1.

[Example 3]

Except that the resin layer of the flexible printed circuit board (FPCB) is stacked so as to extend by 2 mm (i.e., A is 2 mm) compared with the edge portion of the anisotropically conductive adhesive layer, it is performed in the same manner as in Example 1.

[Comparative Example 1]

Except that the resin layer of the flexible printed circuit board (FPCB) is not extended (i.e., A is 0 mm) compared with the edge portion of the anisotropically conductive adhesive layer, it is performed in the same manner as in Example 1.

[Experimental Example: corrosion rate estimation]

The glass assemblies manufactured in Example 1 and Comparative Example 1 are immersed in the state that the current is applied to the electrode layer and the flexible printed circuit board (FPCB) in water at 100 ℃ for 24 hours, and a corrosion rate is measured.

The corrosion rate is calculated as follows and measured for the electrodes up to 1 mm from the edge of the edge electrode layer.

[a corroded electrode amount]/[an entire electrode amount]

(Table 1)

As shown in Table 1, in Example 1 to Example 3 in which a protection adhesive layer is formed, it may be confirmed that the corrosion almost does not exist in the edge electrode layer, but the edge electrode layer is corroded in Comparative Example 1.

FIG. 9 and FIG. 10 show photos of the edge electrode layer after estimating the corrosion rate of Example 1 and Comparative Example 1. The corrosion almost does not exist in the edge electrode layer in FIG. 9, but the end of the edge electrode layer is corroded extensively in Comparative Example 1 of FIG. 10.

While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

<Description of symbols>

10: transparent substrate film,

21: light emitting diode,

22: edge electrode layer,

23: inner electrode layer,

30: anisotropically conductive adhesive layer,

40: flexible printed circuit board (FPCB),

41: electrode portion,

42: resin layer,

50: driving controller,

61: first sealing member,

62: second sealing member,

71: first glass sheet,

72: second glass sheet,

100: transparent display unit,

200: glass assembly

Claims

A transparent display unit comprising:

a transparent substrate film;

an edge electrode layer disposed on the upper surface of the transparent substrate film;

an anisotropically conductive adhesive layer disposed on the edge electrode layer; and

a flexible printed circuit board (FPCB) disposed on the anisotropically conductive adhesive layer and electrically connected to the edge electrode layer through the anisotropically conductive adhesive layer,

wherein the flexible printed circuit board (FPCB) includes an electrode portion and a resin layer, and the resin layer extends from the edge portion of the anisotropically conductive adhesive layer to be in contact with the edge electrode layer.
The transparent display unit of claim 1, further comprising

a driving controller controlling a driving of the transparent display unit,

wherein the flexible printed circuit board (FPCB) electrically connects the edge electrode layer and the driving controller.
The transparent display unit of claim 1 or 2, wherein

a ratio W/L of an entire width W of one or a plurality of flexible printed circuits (FPCB) for the edge portion length L of the transparent substrate film is 0.1 to 0.5.
The transparent display unit of one of the claims 1 to 3, wherein

the thickness of the transparent substrate film is 200 to 300 μm.
The transparent display unit of one of the claims 1 to 4, wherein

the edge electrode layer includes a circuit pattern formed of one or more of a metal, a metallic nanowire, a transparent conductive oxide, a metal mesh, carbon nanotubes, and a graphene.
The transparent display unit of one of the claims 1 to 5, wherein

the anisotropically conductive adhesive layer incudes a resin and a conductive particle dispersed in the resin.
The transparent display unit of one of the claims 1 to 6, wherein

the anisotropically conductive adhesive layer has a thickness of 25 μm to 225 μm.
The transparent display unit of one of the claims 1 to 7, wherein

the resin layer includes one or more of a polyimide resin and a polyester resin.
The transparent display unit of one of the claims 1 to 8, wherein

the flexible printed circuit board (FPCB) has a thickness of 25 μm to 225 μm.
The transparent display unit of one of the claims 1 to 9, wherein

a length of the resin layer extending from the edge portion of the anisotropically conductive adhesive layer is 1 mm or more.
A glass assembly comprising:

a transparent substrate film;

an edge electrode layer disposed on the upper surface of the transparent substrate film;

an anisotropically conductive adhesive layer disposed on the edge electrode layer;

a flexible printed circuit board (FPCB) disposed on the anisotropically conductive adhesive layer and electrically connected to the edge electrode layer through the anisotropically conductive adhesive layer;

a first sealing member disposed on the flexible printed circuit board (FPCB); and

a first glass sheet disposed on the first sealing member,

wherein the flexible printed circuit board (FPCB) includes an electrode portion and a resin layer, and the resin layer extends from the edge portion of the anisotropically conductive adhesive layer to be in contact with the edge electrode layer.
The glass assembly of claim 11, further comprising:

a second sealing member disposed on the lower surface of the transparent substrate film; and

a second glass sheet disposed on the lower surface of the second sealing member.
The glass assembly of claim 11 or 12, wherein

the first sealing member includes one or more among polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), an ionoplast polymer, a cyclo olefin polymer (COP), and polyurethane.
The glass assembly of claim 12 or 13, wherein

the second sealing member includes one or more among polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), an ionoplast polymer, a cyclo olefin polymer (COP), and polyurethane.