KR102449700B1 - Electroluminescent display device - Google Patents

Abstract

The present invention provides a display panel including a light emitting diode and having a polarizing plate on a first surface thereof; a bottom cover positioned on the second surface side of the display panel; a first adhesive pattern positioned between the display panel and the bottom cover and positioned at a corner of the bottom cover and a second adhesive pattern positioned on a side of the bottom cover, wherein the first adhesive pattern includes a flexible bead To provide an electroluminescent display device having lower elasticity than the second adhesive pattern.

Description

Electroluminescent display device

The present invention relates to an electroluminescent display device, and more particularly, to an electroluminescent display device capable of preventing a problem of deformation of a display panel.

Electroluminescent display device, one of the new flat panel displays, is a self-luminous type, so it has superior viewing angle and contrast ratio compared to liquid crystal display devices. , which is advantageous in terms of power consumption.

In addition, DC low voltage driving is possible, the response speed is fast, and since it is all solid, it is strong against external impact, has a wide operating temperature range, and has the advantage of low cost in terms of manufacturing cost.

In an active matrix type electroluminescent display device, a voltage controlling a current applied to a pixel is charged in a storage capacitor, and the voltage is maintained until the next frame signal is applied. , is driven to maintain the light emitting state while one screen is displayed regardless of the number of gate wirings.

An electroluminescent display device includes a display panel including a light emitting diode and a case covering a rear surface of the display panel.

1 is a schematic cross-sectional view of a display panel of a conventional electroluminescent display device.

As shown in FIG. 1 , the display panel 10 of the conventional electroluminescent display device is connected to a substrate 11 , a driving thin film transistor Td positioned on the substrate 11 , and a driving thin film transistor Td. and a light emitting diode (D) to be used, and a polarizing plate (70) on the light emitting diode (D).

A semiconductor layer 20 is formed on the substrate 11 made of glass or plastic. The semiconductor layer 20 may be made of an oxide semiconductor material or made of polycrystalline silicon.

A gate insulating layer 26 made of an insulating material is formed on the entire surface of the substrate 11 on the semiconductor layer 20 . The gate insulating layer 26 may be made of an inorganic insulating material such as silicon oxide or silicon nitride.

A gate electrode 30 made of a conductive material such as metal is formed on the gate insulating layer 26 to correspond to the center of the semiconductor layer 20 .

An interlayer insulating film 36 made of an insulating material is formed on the entire surface of the substrate 11 on the gate electrode 30 . The interlayer insulating layer 36 may be formed of an inorganic insulating material such as silicon oxide or silicon nitride, or an organic insulating material such as benzocyclobutene or photo-acryl.

The interlayer insulating film 36 has first and second contact holes 37 and 38 exposing both sides of the semiconductor layer 20 . The first and second contact holes 37 and 38 are positioned at both sides of the gate electrode 30 to be spaced apart from the gate electrode 30 .

A source electrode 40 and a drain electrode 42 are formed on the interlayer insulating layer 36 using a conductive material such as a metal.

The semiconductor layer 20 , the gate electrode 30 , the source electrode 40 , and the drain electrode 42 form the driving thin film transistor Td.

Although not shown, on the substrate 11 , the gate line and the data line extending in the first and second directions, respectively, the switching thin film transistor connected to the gate line and the data line, and the gate line and the data line are parallel to any one Power wirings spaced apart may be formed.

The gate line and the data line cross each other to define a pixel area, and the driving thin film transistor Td is connected to the switching thin film transistor. In addition, a storage capacitor is provided in the pixel area.

A protective layer 50 having a drain contact hole 52 exposing the drain electrode 42 of the driving thin film transistor Td is formed to cover the driving thin film transistor Td.

A first electrode 60 connected to the drain electrode 42 of the driving thin film transistor Td through the drain contact hole 52 is formed on the passivation layer 50 . Also, a bank 66 covering the edge of the first electrode 60 is formed on the passivation layer 50 . The bank 66 has an opening exposing the center of the first electrode 60 .

A light emitting layer 62 and a second electrode 64 are sequentially stacked on the first electrode 60 .

The first electrode 60 , the second electrode 64 facing the first electrode 60 , and the light emitting layer 62 positioned between the first and second electrodes 60 and 64 form a light emitting diode D . .

In addition, the polarizing plate 70 is positioned above the light emitting diode (D). The light of the light emitting diode D passes through the second electrode 64 to display an image, and the polarizer 70 is positioned on the display surface side of the display panel 10 . For example, the polarizing plate 70 may be attached to the light emitting diode D through an adhesive 72 .

The polarizing plate 70 may be a circular polarizing plate, and as external light is reflected by components such as wiring or electrodes in the display panel 10 , the external contrast ratio is prevented from being lowered.

However, in the conventional electroluminescent display device including the display panel, the display panel is separated from the bottom cover or the display panel is damaged due to deformation problems such as bending of the display panel.

SUMMARY OF THE INVENTION The present invention is to solve the problem of separation and/or damage of a display panel in a conventional electroluminescent display device.

In order to solve the above problems, the present invention provides a display panel including a light emitting diode and having a polarizing plate on a first surface thereof; a bottom cover positioned on the second surface side of the display panel; a first adhesive pattern positioned between the display panel and the bottom cover and positioned at a corner of the bottom cover and a second adhesive pattern positioned on a side of the bottom cover, wherein the first adhesive pattern includes a flexible bead To provide an electroluminescent display device having lower elasticity than the second adhesive pattern.

In the electroluminescent display device according to the present invention, the low elastic first adhesive pattern is formed on the edge of the bottom cover, thereby preventing the display panel from being separated (delamination) or damaged due to the asymmetric structure causing warpage.

Accordingly, it is possible to provide an electroluminescent display device having high reliability and high durability.

1 is a schematic cross-sectional view of a display panel of a conventional electroluminescent display device.
2A to 2C are schematic diagrams for explaining a problem of deformation and separation of a display panel in an electroluminescent display device.
3 is a schematic plan view of an electroluminescent display device according to a first embodiment of the present invention.
4 is a schematic cross-sectional view of an electroluminescent display device according to a first embodiment of the present invention.
5 is a schematic cross-sectional view of a display panel of an electroluminescent display device according to the present invention.
6A to 6D are schematic cross-sectional views illustrating a manufacturing process of an electroluminescent display device according to a first embodiment of the present invention.
7A and 7B are diagrams for explaining a problem occurring when the first and second adhesive patterns are continuously applied.
8 is a graph showing the adhesive force between the first adhesive pattern, the second adhesive pattern, and the bottom cover.
9 is a schematic plan view of an electroluminescent display device according to a second embodiment of the present invention.
10 is a schematic plan view of an electroluminescent display device according to a third embodiment of the present invention.

As described above, in the conventional electroluminescent display device, the display panel is separated from the bottom cover or the display panel is damaged due to the bending of the display panel, which is caused by the asymmetric structure of the display panel.

That is, referring to FIGS. 2A to 2C which are schematic drawings for explaining the problem of deformation and separation of the display panel in the electroluminescent display device together with FIG. 1 , the bottom cover 90 having the adhesive layer 90 formed along the edge. The display panel 10 of the electroluminescent display device is seated to constitute the electroluminescent display device.

That is, the rear surface of the display panel 10 is covered by the bottom cover 90 .

However, the display panel 10 of the electroluminescent display device has an asymmetric structure in which the polarizing plate 70 is located only on one side thereof, that is, on the display surface side.

Accordingly, a large amount of deformation such as a curvature of the display panel 10 occurs, and stress due to the curvature is concentrated at an edge of the display panel 10 . As a result, a problem occurs in that the display panel 10 is separated from the bottom cover 80 .

To prevent this problem, the area of the adhesive may increase, for example, the adhesive may be applied to the entire surface of the bottom cover 80 , but this causes problems such as an increase in the weight of the electroluminescent display device.

Meanwhile, the separation problem of the display panel 10 can be solved by increasing the adhesive force of the adhesive, but the display panel 10 is damaged due to stress concentration at the edge of the display panel 10 .

In order to solve this problem, the present invention provides a display panel including a light emitting diode and having a polarizing plate on a first surface thereof; a bottom cover positioned on the second surface side of the display panel; a first adhesive pattern positioned between the display panel and the bottom cover and positioned at a corner of the bottom cover and a second adhesive pattern positioned on a side of the bottom cover, wherein the first adhesive pattern includes a flexible bead To provide an electroluminescent display device having lower elasticity than the second adhesive pattern.

In the electroluminescent display device of the present invention, the flexible bead is any one of a polymethylmetacrylate (PMMA) bead, a polyurethane bead, and a silicone bead.

In the electroluminescent display device of the present invention, the first adhesive pattern has a first average thickness and the second adhesive pattern has a second average thickness smaller than the first average thickness.

In the electroluminescent display device of the present invention, the first adhesive pattern has a first width and the second adhesive pattern has a second width smaller than the first width.

In the electroluminescent display device of the present invention, the second adhesive pattern has a greater adhesive strength than the first adhesive pattern.

In the electroluminescent display device of the present invention, the second adhesive pattern includes an extension extending to the corner, and the extension is located inside the first adhesive pattern.

The electroluminescent display device of the present invention further includes a third adhesive pattern corresponding to the corner and positioned inside the extension portion and including the flexible bead.

In the electroluminescent display device of the present invention, in the first adhesive pattern, the flexible bead has a first density, and in the third adhesive pattern, the flexible bead has a second density smaller than the first density.

In the electroluminescent display device of the present invention, the first adhesive pattern has lower elasticity than the third adhesive pattern.

In the electroluminescent display device of the present invention, the display panel includes a substrate and a light emitting diode positioned between the substrate and the polarizing plate, and the substrate is in contact with the first and second adhesive patterns.

In the electroluminescent display device of the present invention, the polarizing plate and the bottom cover have a first average distance corresponding to the first adhesive pattern and a second average distance smaller than the first average distance corresponding to the second adhesive pattern. have a distance

In the electroluminescent display device of the present invention, the first adhesive pattern and the second adhesive pattern are spaced apart from each other.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

3 is a schematic plan view of an electroluminescent display device according to a first embodiment of the present invention, FIG. 4 is a schematic cross-sectional view of an electroluminescent display device according to the first embodiment of the present invention, and FIG. It is a schematic cross-sectional view of a display panel of an electroluminescent display device according to the present invention.

3 to 5 , the electroluminescent display device 100 includes a display panel 101 having a polarizing plate 170 disposed on a first side and including a light emitting diode D, and a display panel 101. The bottom cover 180 disposed on the second side of the bottom cover 180 , the first adhesive pattern 190 positioned at the edge of the bottom cover 180 and including the soft bead 192 , and the bottom cover 180 , located on the side of the bottom cover 180 . and a second adhesive pattern 194 .

That is, the display panel 101 is attached (or coupled) to the bottom cover 180 by the first and second adhesive patterns 190 and 194 , and a rear surface thereof is covered and protected by the bottom cover 180 .

The display panel 101 includes a substrate 110 , a driving thin film transistor Td positioned on the substrate 110 , a light emitting diode D connected to the driving thin film transistor Td , and an upper portion of the light emitting diode D . a polarizing plate 170 of

The substrate 110 may be a glass substrate or a flexible plastic substrate. For example, the substrate 110 may be a polyimide substrate.

A semiconductor layer 120 is formed on the substrate 110 . The semiconductor layer 120 may be made of an oxide semiconductor material or made of polycrystalline silicon.

When the semiconductor layer 120 is made of an oxide semiconductor material, a light blocking pattern (not shown) may be formed under the semiconductor layer 120 , and the light blocking pattern prevents light from being incident on the semiconductor layer 120 to prevent light from being incident on the semiconductor layer 120 . (120) to prevent deterioration by light. Alternatively, the semiconductor layer 120 may be made of polycrystalline silicon, and in this case, both edges of the semiconductor layer 120 may be doped with impurities.

A gate insulating layer 122 made of an insulating material is formed on the entire surface of the substrate 110 on the semiconductor layer 120 . The gate insulating layer 122 may be made of an inorganic insulating material such as silicon oxide or silicon nitride.

A gate electrode 130 made of a conductive material such as metal is formed on the gate insulating layer 122 to correspond to the center of the semiconductor layer 120 . Also, a first capacitor electrode (not shown) of the gate line GL and the storage capacitor Cst may be formed on the gate insulating layer 122 . The gate line GL may extend in a first direction, and the first capacitor electrode may be connected to the gate electrode 130 .

In FIG. 5 , the gate insulating film 122 is formed on the entire surface of the substrate 110 . Alternatively, the gate insulating layer 122 may be patterned to have the same shape as the gate electrode 130 .

An interlayer insulating film 136 made of an insulating material is formed on the entire surface of the substrate 110 on the gate electrode 130 . The insulating interlayer 136 may be formed of an inorganic insulating material such as silicon oxide or silicon nitride, or an organic insulating material such as benzocyclobutene or photo-acryl.

The interlayer insulating layer 136 has first and second contact holes 137 and 138 exposing both sides of the semiconductor layer 120 . The first and second contact holes 137 and 138 are positioned at both sides of the gate electrode 130 to be spaced apart from the gate electrode 130 .

In FIG. 5 , first and second contact holes 137 and 138 are also formed in the gate insulating layer 122 . Alternatively, when the gate insulating layer 122 is patterned to have the same shape as the gate electrode 130 , the first and second contact holes 137 and 138 may be formed only in the interlayer insulating layer 136 .

A source electrode 140 and a drain electrode 142 made of a conductive material such as metal are formed on the interlayer insulating layer 136 . Also, a data line DL, a power line PL, and a second capacitor electrode (not shown) extending in the second direction may be formed on the interlayer insulating layer 136 .

The source electrode 140 and the drain electrode 142 are spaced apart from the center of the gate electrode 130 and contact both sides of the semiconductor layer 120 through the first and second contact holes 137 and 138, respectively. . The data line DL extends along the second direction and intersects the gate line GL to define the pixel region P, and the power line PL supplying the high potential voltage is spaced apart from the data line DL. Located. Alternatively, the power line PL may be formed to intersect the data line DL by being spaced apart from the gate line GL on the same layer as the gate line GL. The second capacitor electrode is connected to the source electrode 140 and overlaps the first capacitor electrode to form the storage capacitor Cst using the interlayer insulating film 136 between the first and second capacitor electrodes as a dielectric layer.

The semiconductor layer 120 , the gate electrode 130 , the source electrode 140 , and the drain electrode 142 form a driving thin film transistor Td, and the driving thin film transistor Td is a gate on the semiconductor layer 120 . It has a coplanar structure in which the electrode 130 , the source electrode 140 , and the drain electrode 142 are positioned.

Alternatively, the driving thin film transistor Td may have an inverted staggered structure in which a gate electrode is positioned under a semiconductor layer and a source electrode and a drain electrode are positioned above the semiconductor layer. In this case, the semiconductor layer may be made of amorphous silicon.

As described above, the switching thin film transistor Ts is further formed on the first substrate 110 , and the switching thin film transistor Ts has substantially the same structure as the driving thin film transistor Td.

The gate electrode 130 of the driving thin film transistor Td is connected to the drain electrode (not shown) of the switching thin film transistor Ts, and the source electrode 140 of the driving thin film transistor Td is connected to the power line PL. . In addition, a gate electrode (not shown) and a source electrode (not shown) of the switching thin film transistor Ts are respectively connected to the gate line GL and the data line DL.

A protective layer 144 having a drain contact hole 146 exposing the drain electrode 142 of the driving thin film transistor Td is formed to cover the driving thin film transistor Td.

The first electrode 160 connected to the drain electrode 142 of the driving thin film transistor Td through the drain contact hole 146 is formed on the passivation layer 144 to be separated for each pixel region P. The first electrode 160 may be an anode, and may be made of a conductive material having a relatively large work function value. For example, the first electrode 160 may be made of a transparent conductive material such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO).

Meanwhile, a reflective electrode or a reflective layer may be further formed under the first electrode 160 . For example, the reflective electrode or the reflective layer may be made of an aluminum-palladium-copper (APC) alloy.

Also, a bank 166 covering the edge of the first electrode 160 is formed on the passivation layer 144 . That is, the bank 166 is located at the boundary of the pixel area P. The bank layer 166 has an opening corresponding to the pixel region P, surrounds the pixel region P, and exposes the center of the first electrode 160 .

A light emitting layer 162 is formed on the first electrode 160 . The light emitting layer 162 may include an organic light emitting material such as a phosphorescent compound or a fluorescent compound, or an inorganic light emitting material such as quantum dots.

The light emitting layer 162 may have a single-layer structure of an emitting material layer made of a light emitting material. In addition, in order to increase luminous efficiency, the light emitting layer 162 includes a hole injection layer and a hole transporting layer sequentially stacked between the first electrode 160 and the light emitting material layer, and a light emitting material. It may further include an electron transporting layer and an electron injection layer sequentially stacked on the layer.

A second electrode 164 is formed on the substrate 110 on which the light emitting layer 162 is formed. The second electrode 164 is located on the entire surface of the display area and is made of a conductive material having a relatively small work function value and may be used as a cathode. For example, the second electrode 164 may be formed of any one of aluminum (Al), magnesium (Mg), and an aluminum-magnesium alloy (AlMg).

The first electrode 160, the second electrode 164 facing the first electrode 160, and the light emitting layer 162 positioned between the first and second electrodes 160 and 164 are light emitting diodes (D). make up

In addition, the polarizing plate 170 is positioned above the light emitting diode (D). The light of the light emitting diode D passes through the second electrode 164 to display an image, and the polarizer 170 is positioned on the display surface side of the display panel 101 . For example, the polarizing plate 170 may be attached to the light emitting diode D through the 172 .

The polarizing plate 170 may be a circular polarizing plate, and prevents external light from being reflected by components such as wires or electrodes in the display panel 101, thereby preventing a decrease in external contrast ratio.

The first adhesive pattern 190 includes the soft bead 192 and has low elastic properties. For example, the soft bead 192 may be any one of a polymethylmethacrylate (PMMA) bead, a polyurethane bead, and a silicone bead.

The second adhesive pattern 194 includes components substantially the same as the adhesive components of the first adhesive pattern. That is, the second adhesive pattern 194 does not include the soft bead, and accordingly, the elasticity of the second adhesive pattern 194 is greater than that of the first adhesive 190 .

For example, each of the second adhesive patterns 194 includes a binder, an initiator having about 1 to 5 parts by weight based on the binder, a catalyst having about 1 to 5 parts by weight, and a composition comprising a thixotropic additive having about 10 to 20 parts by weight. is formed by, and the first adhesive pattern 190 is formed of a composition that further includes the soft beads 192 having about 1 to 10 parts by weight with respect to the binder.

For example, the binder may include an acrylic binder such as N-acryloyl morpholine (ACMO), isobornyl acrylate (IBOA), 2-phenoxyethyl acrylate, tetraethyleneglycol diacrylate and/or a urethane binder such as diphenylmethane diisocyanate (MDI), urethane prepolymer. have. The initiator may be phenylbis(2,4,6-trimethylbenzoyl-phspine oxide). As the catalyst, diethanol amine and dibutyl tin dilaurate (DBTL) can be used. Further, the thixotropic additive may be inorganic particles such as TiO2 or SiO2.

The thixotropic additive allows the first and second adhesive patterns 190 and 194 to have great shape. That is, the degree of spreading after application of the adhesive is reduced so that each of the first and second adhesive patterns 190 and 194 has a desired thickness.

As will be described later, when the first and second adhesive patterns 190 and 194 do not include a thixotropic additive, the first and second adhesive patterns 190 and 194 do not have a desired shape, and thus the display panel 101 ) and the bottom cover 180 are completely bonded to each other, causing difficulties in the rework process.

The first adhesive pattern 190 includes about 1 to 10 parts by weight of the soft beads 192 with respect to the binder, and accordingly, the elasticity of the first adhesive pattern 190 is reduced and the stretching characteristics are improved. When the amount of the flexible bead 192 is less than 1 part by weight, the elasticity decrease is reduced, so that the elongation property of the first adhesive pattern 190 is deteriorated, and when the flexible bead 192 exceeds 10 parts by weight, the adhesive characteristic of the first adhesive pattern 190 is This decreases and it is difficult to have a function as an adhesive.

That is, in the electroluminescent display device 100 of the present invention, an adhesive is formed on the edge of the bottom cover 180 , and the adhesive is between the first adhesive pattern 190 and the first adhesive pattern 190 positioned at the corner. It includes a second adhesive pattern 194 positioned on the side, and the first adhesive pattern 190 has smaller elasticity and adhesive force than the second adhesive pattern 194 .

Also, the first adhesive pattern 190 has a first width w1 and the second adhesive pattern 194 has a second width w2 smaller than the first width w1 . Since the first adhesive pattern 190 has a smaller adhesive strength than the second adhesive pattern 194 , the width of the first adhesive pattern 190 is increased to compensate for insufficient adhesive strength. In addition, the first adhesive pattern 190 has a first average thickness, and the second adhesive pattern 194 has a second average thickness smaller than the first average thickness.

Furthermore, since the first adhesive pattern 190 has low elasticity and high elongation characteristics, even if deformation such as bending occurs in the display panel 101 , the problem of separation (peelability) of the display panel 101 does not occur.

The first and second adhesive patterns 190 may be spaced apart from each other. Alternatively, the ends of the first and second adhesive patterns 190 may be connected to each other to form a continuous line.

The length of one side of the first adhesive pattern 190 may be about 100 to 200 mm. If the length of one side of the first adhesive pattern 190 is less than 100 mm, a problem of separation of the display panel 101 may occur at the corner. If the length of one side of the first adhesive pattern 190 is greater than 100 mm, the second adhesive having high adhesive strength Due to the reduction in the area of the pattern 192 , a problem of separation of the display panel 101 from the side may occur.

As described above, since the display panel 101 of the electroluminescent display device 100 has an asymmetric structure including the polarizing plate 170 only on one side thereof, deformation such as warpage occurs in the display panel 101 .

At this time, in the present invention, the first adhesive pattern 190 including the flexible bead 192 having low elasticity and high elongation characteristics connects the display panel 101 and the bottom cover 180 at the edge of the display panel 101 . Due to the adhesion, it is possible to prevent the display panel 101 and the bottom cover 180 from being separated (peeled) from the corners or the display panel 101 from being damaged at the corners.

6A to 6D are schematic cross-sectional views illustrating a manufacturing process of an electroluminescent display device according to a first embodiment of the present invention.

As shown in FIG. 6A , the first adhesive forming the first adhesive pattern 190 including the flexible bead 192 is applied to the edge of the bottom cover 180 and the second adhesive is applied to the side of the bottom cover 180 . A second adhesive constituting the pattern 194 is applied. The first and second adhesive patterns 190 are applied at intervals of a first distance d1. The first adhesive is applied to have a greater width than the second adhesive. In addition, the first adhesive is applied to have a first thickness t1, and the second adhesive is applied to have a second thickness t2 that is smaller than the first thickness t1.

At this time, there is no limitation in the order of application of the first and second adhesives.

When the first and second adhesives are applied, as shown in FIG. 6B , the first and second adhesives are spread so that the first and second adhesive patterns 190 form a second distance d2 smaller than the first distance d1. ) has an interval of In this case, the second distance d2 may be equal to or greater than 0. (d2≥0)

On the other hand, when the adhesive forming the first and second adhesive patterns 190 and 194 is continuously applied so that the ends of the first and second adhesive patterns 190 and 194 are connected to each other, that is, when the adhesive forming the first and second adhesive patterns 190 and 194 is continuously applied, the adhesive spreads A problem in that the first adhesive pattern 190 having a thickness overlaps the second adhesive pattern 194 and covers the second adhesive pattern 194 may occur.

Referring to FIGS. 7A and 7B , which are drawings for explaining a problem that occurs during continuous application of the first and second adhesive patterns, the first and second adhesive patterns 190 and 194 are formed on the bottom cover 180 . When the first and second adhesives are continuously applied, the ends of the first adhesive patterns 190 are placed on the second adhesive patterns 194 while the first and second adhesives are spread. That is, the ends of the first and second adhesive patterns 190 and 194 overlap.

By measuring the adhesive force between each of the first and second adhesive patterns 190 and 194 and the bottom cover 180 and between the first and second adhesive patterns 190 and 194, Table 1 and FIG. 8 below shown in "Sample1" is the result of measuring the adhesive force between the second adhesive pattern 194 and the bottom cover 180, "Sample2" is the result of measuring the adhesive force between the first adhesive pattern 190 and the bottom cover 180, and "Sample3"" is the result of measuring the adhesive force between the first and second adhesive patterns 190 and 194 . (Unit [kgf/cm ² ])

[Table 1]

As shown in Table 1 and FIG. 8, the adhesive force of the first adhesive pattern 190 is lowered by the soft bead, but the adhesive force between the first adhesive pattern 190 and the bottom cover 180 is satisfactory for adhesive reliability. have a range However, the adhesive force between the first and second adhesive patterns 190 and 194 is smaller than a range satisfying adhesive reliability.

As described above, the display panel 101 is attached in a state where the first adhesive pattern 190 has a non-flat upper surface by overlapping the first and second adhesive patterns 190 and 194, and the first adhesive pattern 190 is attached to the first adhesive pattern. Since the adhesive force between the pattern 190 and the second adhesive pattern 194 is weak, adhesion failure of the display panel 101 may occur at a portion where the first and second adhesive patterns 190 and 194 overlap.

Accordingly, in the present invention, the first and second adhesives are applied spaced apart by a first distance d1, and as a result, the first and second adhesive patterns 190 and 194 do not overlap.

Next, as shown in FIG. 6C , the display panel 101 having the polarizing plate 170 is attached to the bottom cover 180 while making contact with the first adhesive pattern 190 . When the display panel 101 is attached, the display panel 101 is in a flat state so that the display panel 101 is in contact with the first adhesive pattern 190 and is spaced apart from the second adhesive pattern 194 .

That is, when the display panel 101 is attached, the display panel 101 is temporarily bonded by the first adhesive pattern 190 . Accordingly, when a problem such as alignment failure between the display panel 101 and the bottom cover 180 occurs, the display panel 101 can be easily separated to perform a rework process.

After the display panel 101 and the bottom cover 180 are attached, the display panel 101 is bent due to the asymmetric structure of the display panel 101 . At this time, the first adhesive pattern 190 has a high elongation characteristic by the flexible bead 192 , and as shown in FIG. 6D , the display panel 101 is separated from the edge while the first adhesive pattern 190 is stretched. or breakage is prevented.

As a result, the polarizing plate 170 or the display panel 101 has a first average distance (distance) from the bottom cover 180 to correspond to the first adhesive pattern 190 and to correspond to the second adhesive pattern 194 . The second average interval is smaller than the first average interval.

9 is a schematic plan view of an electroluminescent display device according to a second embodiment of the present invention.

As shown in FIG. 9 , the electroluminescent display 200 includes a display panel (101 in FIG. 5) having a polarizing plate (170 in FIG. 5) disposed on the first side and including a light emitting diode (D in FIG. 5); , a bottom cover 280 disposed on the second side of the display panel 101, and a first adhesive pattern 290 positioned at the edge of the bottom cover 280 and including a soft bead (192 in FIG. 4); It is formed on the side of the bottom cover 280 and includes a second adhesive pattern 294 having an extension to the corner.

That is, unlike the electroluminescent display device 200 of the first embodiment shown in FIG. 3 , the second adhesive pattern 294 has a closed shape along the edge of the bottom cover 280 and the first adhesive pattern. (290) is located on the inside.

The first adhesive pattern 290 includes a soft bead so that elasticity is reduced. That is, the first adhesive pattern 290 has less elasticity than the second adhesive pattern 294 .

The first adhesive pattern 290 has a first width w1 and the second adhesive pattern 294 has a second width w2 smaller than the first width w1. In addition, the first adhesive pattern 290 has a first average thickness, and the second adhesive pattern 294 has a second average thickness that is smaller than the first average thickness.

Also, the first and second adhesive patterns 290 and 294 may be spaced apart from each other.

10 is a schematic plan view of an electroluminescent display device according to a second embodiment of the present invention.

As shown in FIG. 10 , the electroluminescent display device 300 includes a display panel ( 101 in FIG. 5 ) having a polarizing plate ( 170 in FIG. 5 ) disposed on the first side and including a light emitting diode (D in FIG. 5 ); , a bottom cover 380 disposed on the second side of the display panel 101, and a first adhesive pattern 390 positioned at a corner of the bottom cover 380 and including a soft bead (192 in FIG. 4); It is formed on the side of the bottom cover 380 and includes a second adhesive pattern 394 provided with an extension to the edge, and a third adhesive pattern 396 positioned inside the second adhesive pattern 394 corresponding to the edge. do.

That is, the second adhesive pattern 394 has a closed shape along the edge of the bottom cover 380 , and the first and third adhesive patterns 390 and 396 are extended portions of the second adhesive pattern 394 . Corresponding to , the extension of the second adhesive pattern 394 is positioned between the first and third adhesive patterns 390 and 396 .

Each of the first and third adhesive patterns 390 and 396 includes a soft bead to reduce elasticity. That is, each of the first and third adhesive patterns 390 and 396 has less elasticity than the second adhesive pattern 394 .

The first adhesive pattern 390 has a first width w1 , the second adhesive pattern 294 has a second width w2 , and the third adhesive pattern 396 has a third width w3 . . The second width w2 is smaller than the first and third widths w1 and w3. Also, the first width w1 may be equal to or greater than the third width w3. That is, the first adhesive pattern 390 located at the outermost side is applied with a larger width and thickness than the third adhesive pattern 396 , and is displayed by the first adhesive pattern 390 when the display panel 101 is bent. Separation of the panel 101 edge is prevented.

In addition, the flexible bead may have a first density in the first adhesive pattern 390 and a second density smaller than the first density in the third adhesive pattern 396 . That is, since the first adhesive pattern 390 positioned at the outermost side has less elasticity than the third adhesive pattern 396 , separation of the display panel from the end of the display panel 101 can be prevented.

In addition, the first adhesive pattern 290 has a first average thickness, and the second adhesive pattern 294 has a second average thickness that is smaller than the first average thickness.

Also, the first and second adhesive patterns 290 and 294 may be spaced apart from each other.

As described above, the low-elasticity first adhesive pattern is formed at the edge of the bottom cover, thereby preventing the display panel from being separated (delamination) or damaged due to the asymmetric structure. Accordingly, it is possible to provide an electroluminescent display device having high reliability and high durability.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention described in the claims below. You will understand that it can be done.

100, 200, 300: electroluminescent display device 101: display panel
110: substrate 170: polarizing plate
180, 280, 380: bottom cover 190, 290, 390: first adhesive pattern
192: soft beads 194, 294, 394: second adhesive pattern
396: third adhesive pattern

Claims (14)

a display panel including a light emitting diode and having a polarizing plate on a first surface thereof;
a bottom cover positioned on the second surface side of the display panel;
a first adhesive pattern positioned between the display panel and the bottom cover and positioned at a corner of the bottom cover and a second adhesive pattern positioned on a side of the bottom cover;
The first adhesive pattern includes a soft bead, and has lower elasticity than the second adhesive pattern.
The method of claim 1,
The flexible bead is any one of a polymethylmethacrylate (PMMA) bead, a polyurethane bead, and a silicon bead.
The method of claim 1,
The first adhesive pattern has a first average thickness and the second adhesive pattern has a second average thickness smaller than the first average thickness.
The method of claim 1,
The first adhesive pattern has a first width and the second adhesive pattern has a second width smaller than the first width.
The method of claim 1,
The second adhesive pattern has an adhesive force greater than that of the first adhesive pattern.
The method of claim 1,
The second adhesive pattern includes an extension extending to the corner, and the extension is located inside the first adhesive pattern.
7. The method of claim 6,
The electroluminescent display device further comprising a third adhesive pattern corresponding to the corner and positioned inside the extension portion and including the flexible bead.
8. The method of claim 7,
In the first adhesive pattern, the flexible bead has a first density, and in the third adhesive pattern, the flexible bead has a second density smaller than the first density.
8. The method of claim 7,
An electroluminescence display having lower elasticity in the first adhesive pattern than in the third adhesive pattern.
The method of claim 1,
The display panel includes a substrate, and a light emitting diode positioned between the substrate and the polarizing plate;
and the substrate is in contact with the first and second adhesive patterns.
The method of claim 1,
The polarizing plate and the bottom cover have a first average distance corresponding to the first adhesive pattern and a second average distance that is smaller than the first average distance corresponding to the second adhesive pattern.
The method of claim 1,
The first adhesive pattern and the second adhesive pattern are spaced apart from each other. The method of claim 1,
the first adhesive pattern has a first average thickness and the second adhesive pattern has a second average thickness that is smaller than the first average thickness;
The polarizing plate and the bottom cover have a first average distance corresponding to the first adhesive pattern and a second average distance that is smaller than the first average distance corresponding to the second adhesive pattern.
The method of claim 1,
and the second adhesive pattern does not include a soft bead.

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