KR102452863B1 - Digitizer and image display device including the same - Google Patents

Abstract

According to embodiments of the present invention, a digitizer and an image display device including the same are provided. The digitizer includes a base layer, a lower conductive layer disposed on the upper surface of the base layer, an interlayer insulating layer formed on the upper surface of the base layer to cover the lower conductive layer, an upper conductive layer disposed on the interlayer insulating layer, and a bottom surface of the base layer and a support layer coupled to and having a thickness equal to or greater than the thickness of the base layer and an elastic modulus equal to or greater than the elastic modulus of the base layer.

Description

Digitizer and image display device including same

The present invention relates to a digitizer and an image display device including the same. More particularly, it relates to a digitizer including a multilayer conductive structure and an image display device including the same.

Recently, various sensing functions and communication functions are combined in an image display device, and are implemented in the form of, for example, a smartphone. For example, electronic devices in which a touch panel or a touch sensor is attached to a display panel of the image display device to select a menu displayed on a window surface to implement an information input function are being developed.

In addition, as disclosed in Korean Patent No. 10-1750564, a digitizer that converts analog coordinate information into a digital signal by an electromagnetic method is disposed on the back side of the image display device.

Recently, a flexible display having flexibility that can be folded or bent is being developed, and accordingly, a sensor structure such as the digitizer needs to be developed to have appropriate physical properties, design, and structure so that it can also be applied to the flexible display.

For example, in the case of a digitizer applied to a thin display device, a crack of a conductive pattern or an electrode may easily occur in a bending portion. Therefore, there is a need to develop a digitizer capable of maintaining reliability even after repeated bending.

Korean Patent Publication No. 10-1750564

One object of the present invention is to provide a digitizer having improved mechanical and electrical reliability.

An object of the present invention is to provide an image display device including a digitizer having improved mechanical and electrical reliability.

1. base layer; a lower conductive layer disposed on the upper surface of the base layer; an interlayer insulating layer formed on the upper surface of the base layer and covering the lower conductive layer; an upper conductive layer disposed on the interlayer insulating layer; and a support layer coupled to the bottom surface of the base layer and having a thickness equal to or greater than the thickness of the base layer and an elastic modulus equal to or greater than the elastic modulus of the base layer, the digitizer.

2. In the above 1, the thickness of the support layer is greater than the thickness of the base layer, the elastic modulus of the support layer is greater than the elastic modulus of the base layer, the digitizer.

3. The digitizer according to the above 2, wherein the ratio of the elastic modulus of the base layer to the elastic modulus of the support layer is 1.5 to 2.

4. The digitizer according to the above 1, wherein the elastic modulus of the base layer is 2 to 6 GPa, and the elastic modulus of the support layer is 4 to 10 GPa.

5. In the above 1, the tensile breaking strength of the support layer is greater than the tensile breaking strength of the base layer. wherein the tensile yield strength of the support layer is greater than the tensile yield strength of the base layer.

6. The digitizer according to the above 1, wherein the elongation of the support layer is smaller than the elongation of the base layer.

7. The digitizer according to 1 above, wherein the base layer and the support layer include the same type of organic material.

8. The digitizer according to the above 7, wherein the base layer and the support layer include a polyimide-based material.

9. The above 1, further comprising an adhesive layer formed between the support layer and the base layer, digitizer.

10. The method of 1 above, wherein the lower conductive layer includes a plurality of first lower conductive lines and a plurality of second lower conductive lines extending in a second direction parallel to the upper surface of the base layer, and the upper conductive layer The layer includes a plurality of first upper conductive lines and a plurality of second upper conductive lines extending in a first direction parallel to the upper surface of the base layer and perpendicular to the second direction.

11. The method of 10 above, further comprising: first contacts electrically connecting the first upper conductive lines and the second lower conductive lines to form a first conductive coil; and

and second contacts electrically connecting the first lower conductive lines and the second upper conductive lines to form a second conductive coil.

12. The method of 11 above, wherein the first conductive coil extends in the first direction, a plurality of the first conductive coils are arranged along the second direction, and the second conductive coil extends in the second direction. and a plurality of the second conductive coils are arranged along the first direction.

13. The digitizer according to the above 10, wherein the base layer includes a bending region in the central portion.

14. The digitizer of 13 above, wherein a bending axis of the bending region intersects the first upper conductive line and is parallel to the first lower conductive line.

15. Display panel; and a digitizer according to the above-described embodiments disposed under the display panel.

16. The image display device according to 15 above, further comprising a touch sensor disposed on the display panel.

17. The method of 16 above, further comprising a rear cover and a window substrate,

The touch sensor is disposed between the window substrate and the display panel, and the digitizer is disposed between the display panel and the rear cover.

According to embodiments of the present invention, a support layer may be additionally coupled under the base layer of the digitizer. The support layer may have a thickness and an elastic modulus equal to or greater than the thickness and elastic modulus of the base layer. Tensile stress generated during bending/folding of the digitizer may be reduced or buffered through the support layer.

Accordingly, it is possible to suppress the tensile stress applied to the conductive layer or wiring of the digitizer, and to implement a stable electromagnetic induction effect even under severe conditions.

According to exemplary embodiments, a lower conductive layer and an upper conductive layer may be sequentially stacked on the upper surface of the base layer. Accordingly, it is possible to prevent cracks in the conductive layer by uniformizing the direction of stress during bending.

In some embodiments, the upper conductive layer may include an upper conductive line crossing a bending axis, and the lower conductive layer may include a lower conductive line parallel to the bending axis. By forming the thickness of the upper conductive line smaller than that of the lower conductive line, electrode cracks may be suppressed and bending characteristics may be improved.

1 is a schematic cross-sectional view showing a digitizer according to exemplary embodiments.
2 and 3 are schematic plan views illustrating conductive coils included in a digitizer according to example embodiments.
4 is a schematic plan view illustrating a digitizer according to exemplary embodiments.
5 is a schematic cross-sectional view illustrating an image display apparatus according to example embodiments.

Embodiments of the present invention include a multilayer conductive structure and a multilayer insulating structure, and provide a digitizer having improved bending reliability and electrical reliability. Also provided is an image display device including a digitizer.

Hereinafter, with reference to the drawings, embodiments of the present invention will be described in more detail. However, the following drawings attached to the present specification illustrate preferred embodiments of the present invention, and serve to further understand the technical spirit of the present invention together with the above-described content of the present invention, so the present invention is described in such drawings It should not be construed as being limited only to the matters.

In the drawings below, two directions parallel to and intersecting with the upper surface of the digitizer 100 or the base layer 105 are defined as a first direction and a second direction. For example, the first direction and the second direction may cross each other perpendicularly.

The first direction may correspond to a width direction, a row direction, or an X-direction of the digitizer 100 . The second direction may correspond to a longitudinal direction, a column direction, or a Y-direction of the digitizer 100 .

1 is a schematic cross-sectional view showing a digitizer according to exemplary embodiments.

Referring to FIG. 1 , the digitizer 100 may include a lower conductive layer 110 and an upper conductive layer 130 formed on a base layer 105 . The lower conductive layer 110 and the upper conductive layer 130 may be separated in different layers with the interlayer insulating layer 120 interposed therebetween.

The substrate layer 105 is used to encompass a substrate or a film type substrate for forming the conductive layers 110 and 130 and the interlayer insulating layer 120 . For example, the base layer 105 may include a polymer applicable to a flexible display. Examples of the polymer include cyclic olefin polymer (COP), polyethylene terephthalate (PET), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), poly Allylate (polyallylate), polyimide (PI), cellulose acetate propionate (CAP), polyethersulfone (PES), cellulose triacetate (TAC), polycarbonate (PC), cyclic olefin copolymer (COC), poly Methyl methacrylate (PMMA), etc. are mentioned.

Preferably, the base layer 105 may include polyimide to secure stable bending properties.

The lower conductive layer 110 and the upper conductive layer 130 may each include a low-resistance metal. For example, the lower conductive layer 110 and the upper conductive layer 130 are silver (Ag), gold (Au), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium ( Cr), titanium (Ti), tungsten (W), niobium (Nb), tantalum (Ta), vanadium (V), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), zinc ( Zn), tin (Sn), molybdenum (Mo), calcium (Ca), or an alloy containing at least two of them.

Preferably, the lower conductive layer 110 and the upper conductive layer 130 may include copper or a copper alloy to realize low resistance.

The interlayer insulating layer 120 may be formed on the upper surface of the base layer 105 to cover the lower conductive layer 110 . The interlayer insulating layer 120 may include an organic insulating material such as an epoxy-based resin, an acrylic resin, a siloxane-based resin, or a polyimide-based resin, or an inorganic insulating material such as silicon oxide or silicon nitride. Preferably, the interlayer insulating layer 120 may be formed using an organic insulating material to improve flexible properties.

In some embodiments, the interlayer insulating layer 120 may have a multilayer structure. For example, the interlayer insulating layer 120 may include a first interlayer insulating layer 122 and a second interlayer insulating layer 124 sequentially stacked from the base layer 105 .

Accordingly, even when the thickness of the lower conductive layer 110 is increased, the interlayer insulating layer 120 having a sufficient thickness for forming the contacts 135 and 137 (refer to FIGS. 2 and 3 ) can be formed. Also, as will be described later, a neutral plane may be easily formed in the interlayer insulating layer 120 to be adjacent to the conductive layers 110 and 130 .

The upper conductive layer 130 may be formed on the interlayer insulating layer 120 . In some embodiments, the passivation layer 140 may be formed on the interlayer insulating layer 120 to cover the upper conductive layer 130 . The passivation layer 140 may include an organic insulating material such as an epoxy-based resin, an acrylic resin, a siloxane-based resin, or a polyimide-based resin, or an inorganic insulating material such as silicon oxide or silicon nitride. Preferably, the passivation layer 140 may be formed using an organic insulating material to improve flexible properties.

Each of the interlayer insulating layer 120 and the passivation layer 140 may have a thickness in the range of about 1.5 to 20 μm to improve bending properties.

According to exemplary embodiments, the support layer 90 may be coupled to the bottom surface of the base layer 105 . For example, the support layer 90 may be attached on the bottom surface of the base layer 105 through the adhesive layer 95 .

In some embodiments, the support layer 90 may include a resin material substantially the same as or similar to the above-described resin material used in the base layer 105 . In one embodiment, the base layer 105 and the support layer 90 may include a polyimide-based material.

The support layer 90 may be provided as a reinforcing layer that converts or relieves stress generated during a folding or bending operation of the digitizer 100 . For example, when excessive tensile stress is applied by bending of the digitizer 100, the tensile stress is reduced by the support layer 90, or the tensile stress is converted into compression and the conductive layer ( 110, 130).

Accordingly, the formation of the neutral plane may be promoted, and fracture and cracking of the conductive layers 110 and 130 due to tensile stress may be suppressed.

According to exemplary embodiments, the thickness of the support layer 90 may be greater than or equal to the thickness of the base layer 105 . Preferably, the thickness of the support layer 90 may be greater than the thickness of the base layer 105 .

According to exemplary embodiments, the elastic modulus of the support layer 90 may be greater than or equal to the elastic modulus of the base layer 105 . Preferably, the elastic modulus of the support layer 90 may be greater than that of the base layer 105 .

As described above, by adjusting the thickness and the elastic modulus of the support layer 90, the stress generated in the base layer 105 can be reduced or suppressed, and the tensile stress transferred to the conductive layers 110 and 130 can be blocked or reduced. have.

In some embodiments, the thickness of the base layer 105 may be about 10 to 30㎛, the thickness of the support layer 90 may be about 25 to 40㎛.

In some embodiments, the ratio of the elastic modulus of the base layer 105 to the elastic modulus of the support layer 90 may be about 1.5 to 2, preferably less than 2.

In some embodiments, the elastic modulus of the base layer 105 may be about 2 to 6 GPa, and the elastic modulus of the support layer 90 may be about 4 to 10 GPa, preferably about 6 to 10 GPa.

Within the above-described thickness and elastic modulus range, it is possible to more effectively implement tensile stress buffering and bending durability improvement through the support layer 90 .

The tensile strength at break and the tensile yield strength of the support layer 90 may be greater than the tensile strength at break and the tensile yield strength of the base layer 105 , respectively.

In some embodiments, the ratio of the tensile breaking strength of the support layer 90 to the tensile breaking strength of the base layer 105 may be about 1.5 to 3. In some embodiments, a ratio of the tensile yield strength of the support layer 90 to the tensile yield strength of the base layer 105 may be about 1.1 to 2.

Within the above-described range, the durability against the overall bending of the digitizer 100 may be further improved.

For example, the tensile breaking strength of the base layer 105 may be about 100 to 200 MPa, and the tensile yield strength may be about 100 to 150 MPa. The tensile breaking strength of the support layer 90 may be about 250 to 400 MPa, and the tensile yield strength may be about 150 to 200 MPa.

For example, the tensile breaking strength and the tensile yield strength may mean strength in a row direction or an X direction of a digitizer.

In some embodiments, the elongation of the support layer 90 may be less than the elongation of the base layer 105 . Accordingly, even when the base layer 105 is excessively stretched and damaged by bending/folding, mechanical stability may be maintained or secured by the support layer 90 .

For example, the elongation of the support layer 90 may be adjusted to be smaller than the elongation of the base layer 105 in the range of 20 to 70%. In one embodiment, the elongation of the base layer 105 may be 40 to 80%, and the elongation of the support layer 90 may be 20 to 40%.

2 and 3 are schematic plan views illustrating conductive coils included in a digitizer according to example embodiments.

2 and 3 , the digitizer 100 according to example embodiments may include a first conductive coil 50 and a second conductive coil 70 .

The first conductive coil 50 and the second conductive coil 70 may be defined by combining the lower conductive layer 110 and the upper conductive layer 130 by the contacts 135 and 137 .

The lower conductive layer 110 may include a first lower conductive line 112 (see FIG. 3 ) and a second lower conductive line 114 (see FIG. 2 ). The upper conductive layer 130 may include a first upper conductive line 132 (see FIG. 2 ) and a second upper conductive line 134 (see FIG. 3 ).

The first lower conductive line 112 and the second lower conductive line 114 may extend in the second direction. The first upper conductive line 132 and the second upper conductive line 134 may extend in a first direction.

As shown in FIG. 2 , the first upper conductive line 132 of the upper conductive layer 130 and the second lower conductive line 114 of the lower conductive layer 110 are coupled to each other to form a first conductive coil 50 . can form.

The first upper conductive line 132 and the second lower conductive line 114 may together form a first conductive coil 50 to serve as a sensing line for an input pen through electromagnetic induction.

For example, the first upper conductive line 132 and the second lower conductive line 114 may be electrically connected to each other through the first contact 135 . A plurality of first upper conductive lines 132 and a plurality of second lower conductive lines 114 are electrically connected to each other through a plurality of first contacts 135 to form a single first conductive coil 50 . A plurality of conductive loops may be included. For example, four first conductive loops may be included in one first conductive coil 50 .

In some embodiments, the first conductive loops may have different sizes or areas in a planar direction. The first contact 135 may pass through the interlayer insulating layer 120 to be formed substantially integrally with the first upper conductive line 132 .

A first input line 113 and a first output line 115 may be connected to any one of the first conductive loops. For example, the first input line 113 may be connected to an innermost first conductive loop among the first conductive loops. The first output line 115 may be connected to an outermost first conductive loop among the first conductive loops.

The current input from the first input line 113 may alternately cycle through the lower conductive layer 110 and the upper conductive layer 130 through the first conductive loops, and may be discharged through the first output line 115 . have.

In some embodiments, the first input line 113 and the first output line 115 may be included in the lower conductive layer 110 .

In some embodiments, the lower conductive layer 110 may include a first internal connection line 114a. For example, adjacent first conductive loops may be connected by a first internal connection line 114a.

As shown in FIG. 3 , the first lower conductive line 112 of the lower conductive layer 110 and the second upper conductive line 134 of the upper conductive layer 130 are coupled to each other to form a second conductive coil 70 . can form.

The first lower conductive line 112 and the second upper conductive line 134 may be provided together as a sensing line for an input pen through electromagnetic induction by forming a second conductive coil 70 together.

For example, the first lower conductive line 112 and the second upper conductive line 134 may be electrically connected to each other through the second contact 137 . A plurality of first lower conductive lines 112 and a plurality of second upper conductive lines 134 are electrically connected to each other through a plurality of second contacts 137 to form a single second conductive coil 70 . A plurality of conductive loops may be included. For example, four second conductive loops may be included in one second conductive coil 70 .

In some embodiments, the second conductive loops may have different sizes or areas in a planar direction. The second contact 137 may be formed substantially integrally with the second upper conductive line 134 through the interlayer insulating layer 120 .

A second input line 117 and a second output line 119 may be connected to any one of the second conductive loops. For example, the second input line 117 may be connected to an innermost second conductive loop among the second conductive loops. The second output line 119 may be connected to an outermost second conductive loop among the second conductive loops.

The current input from the second input line 117 may alternately cycle through the lower conductive layer 110 and the upper conductive layer 130 through the second conductive loops, and may be discharged through the second output line 119 . have.

In some embodiments, the second input line 117 and the second output line 119 may be included in the lower conductive layer 110 .

In some embodiments, the upper conductive layer 130 may further include an external connection line 134a. For example, the second input line 117 and the second output line 119 may be connected through the second conductive loop and the second contact 137 by the external connection line 134a.

In an embodiment, the external connection line 134a may be connected to two different second conductive coils. For example, the output line 119 connected to one of the second conductive coils 70 may be connected to the input line 117 of the other second conductive coil 70 through an external connection line 134a.

In some embodiments, the upper conductive layer 130 may further include a second internal connection line 134b. For example, adjacent second conductive loops in the second conductive coil 70 may be connected to each other by the second internal connection line 134b.

Although it is illustrated that four conductive loops are included in one conductive coil in FIGS. 2 and 3 , the number of conductive loops in the conductive coil may be adjusted in consideration of the size and resolution of the image display device.

As described with reference to FIGS. 2 and 3 , the first conductive coil 50 and the second conductive coil 70 may each include a plurality of conductive loops having different sizes.

Accordingly, it is possible to sufficiently increase the magnetic field strength generated by the digitizer 100 , so that, for example, energy transfer to the input pen in contact with the window surface of the image display apparatus can be efficiently enhanced.

In addition, since the conductive loop is formed by connecting the lower conductive layer 110 and the upper conductive layer 130 through the contacts 135 and 137 , the number of loops of the conductive coil in a limited space is efficiently increased and electromagnetic induction efficiency is achieved. can improve

In example embodiments, both the lower conductive layer 110 and the upper conductive layer 130 may be disposed on the upper surface of the base layer 105 . Accordingly, when bending or folding through the base layer 105 , the stress direction for the lower conductive layer 110 and the upper conductive layer 130 may be adjusted in the same manner.

For example, when tensile stress is applied to the bottom surface of the base layer 105 , compressive stress may be applied to the lower conductive layer 110 and the upper conductive layer 130 . Accordingly, a neutral plane in which stress is canceled may be easily generated to be adjacent to the conductive layers 110 and 130 . Accordingly, stress applied to the conductive layers 110 and 130 may be relieved, thereby reducing or preventing electrode cracking due to bending.

In addition, according to exemplary embodiments, the support layer 90 is coupled under the base layer 105 to facilitate transmission of compressive stress to the lower conductive layer 110 and the upper conductive layer 130 . Accordingly, generation of the neutral plane is also promoted, and bending reliability may be further improved.

In example embodiments, the thickness of the lower conductive layer 110 may be greater than the thickness of the upper conductive layer 130 . For example, the thickness of the first lower conductive line 112 may be greater than the thickness of the first upper conductive line 132 .

As will be described later with reference to FIG. 4 , the first upper conductive line 132 may extend in a first direction (eg, a row direction or a width direction) and intersect a bending axis. For example, the first upper conductive line 132 may be perpendicular to the bending axis. The first lower conductive line 112 may extend in a second direction (a column direction or a length direction) and may be substantially parallel to the bending axis.

In some embodiments, by reducing the thickness of the first upper conductive line 132 to which bending stress is easily transmitted as it intersects the bending axis, prevention of cracks in the conductive line may be reduced or suppressed. Since the first lower conductive line 112, which is parallel to the bending axis and is relatively free from bending stress, is formed to have a large thickness, a sufficient electromagnetic induction effect may be realized by expanding a current path through the conductive coil.

In an embodiment, the second lower conductive line 114 may also have a greater thickness than the second upper conductive line 134 .

In some embodiments, the thickness of the lower conductive layer 110 (the first lower conductive line or the second lower conductive line) may be about 5 to 20 μm, preferably 10 to 20 μm. The thickness of the upper conductive layer 130 (the first upper conductive line or the second upper conductive line) may be 6 μm or less, preferably about 1 to 6 μm.

4 is a schematic plan view illustrating a digitizer according to exemplary embodiments. For convenience of description, the detailed structure/configuration of the conductive coil is omitted in FIG. 4 .

Referring to FIG. 4 , a plurality of first conductive coils 50 and second conductive coils 70 may be arranged on the upper surface of the base layer 105 .

The first conductive coil 50 may extend in the first direction or the row direction. The plurality of first conductive coils 50 may be arranged along the second direction or the column direction.

For example, n first conductive coils 50 - 1 to 50 - n may be sequentially arranged along the second direction (n is a natural number).

The second conductive coil 70 may extend in the second direction or the column direction. The plurality of second conductive coils 70 may be arranged along the first direction or the row direction.

For example, m second conductive coils 70 - 1 to 70 - m may be sequentially arranged in the first direction.

A bending area BA may be included in the central portion of the base layer 105 . A bending axis 80 extending in the second direction may be positioned in the bending area BA. The digitizer 100 according to example embodiments may be bent or folded around the bending axis 80 .

In some embodiments, the thickness of the first upper conductive line 132 or the second upper conductive line 134 crossing the bending axis 80 may be relatively small. Accordingly, it is possible to prevent cracking of the upper conductive layer 130 to which bending stress is directly applied and to increase flexibility.

The thicknesses of the first lower conductive line 112 and the second lower conductive line 114 parallel to the bending axis 80 and having relatively small bending stress are increased to reduce resistance and improve the efficiency of generating a magnetic field through the conductive coil. can do it

5 is a schematic cross-sectional view illustrating an image display apparatus according to example embodiments.

Referring to FIG. 5 , the image display apparatus may include the display panel 360 , the touch sensor 200 , and the digitizer 100 according to the above-described exemplary embodiments.

The digitizer 100 may be disposed under the display panel 360 . For example, the digitizer 100 may be disposed between the display panel 360 and the rear cover 380 .

The digitizer 100 includes relatively thick conductive lines for efficiency in generating a magnetic field using electromagnetic induction, and may include a plurality of conductive coils. Accordingly, the digitizer 100 may be disposed under the display panel 360 so as not to be recognized by a user of the image display apparatus.

The display panel 360 may include a pixel electrode 310 , a pixel defining layer 320 , a display layer 330 , a counter electrode 340 , and an encapsulation layer 350 disposed on the panel substrate 300 . can

A pixel circuit including a thin film transistor (TFT) may be formed on the panel substrate 300 , and an insulating layer covering the pixel circuit may be formed. The pixel electrode 310 may be electrically connected to, for example, a drain electrode of a TFT on the insulating layer.

The pixel defining layer 320 may be formed on the insulating layer to expose the pixel electrode 310 to define a pixel area. A display layer 330 is formed on the pixel electrode 310 , and the display layer 330 may include, for example, a liquid crystal layer or an organic light emitting layer.

A counter electrode 340 may be disposed on the pixel defining layer 320 and the display layer 330 . The opposing electrode 340 may be provided as a common electrode or a cathode of the image display device, for example. An encapsulation layer 350 for protecting the display panel 360 may be stacked on the opposite electrode 340 .

The touch sensor 200 may be stacked on the display panel 360 and disposed toward the window substrate 230 . The touch sensor 200 may generate capacitance by a user's touch input through the surface of the window substrate 230 . Accordingly, the touch sensor 200 may include a sensing electrode or sensing channels having a thickness smaller than that of the conductive layer included in the digitizer 100 so as not to be recognized by the user. For example, the thickness of the sensing electrode or the sensing channel may be less than 1 μm or less than 0.5 μm.

Each of the sensing electrodes or the sensing channels may be independently disposed in one single layer to interact with an adjacent sensing electrode or sensing channel to generate capacitance.

The touch sensor 200 may be coupled to the display panel 360 through the adhesive layer 260 .

The window substrate 230 includes, for example, a hard coating film and thin glass, and in an embodiment, a light blocking pattern 235 may be formed on a peripheral portion of one surface of the window substrate 230 . The light blocking pattern 235 may include, for example, a color printing pattern. A bezel part or a non-display area of the image display device may be defined by the light blocking pattern 235 .

A polarization layer 210 may be disposed between the window substrate 230 and the touch sensor 200 . The polarizing layer 210 may include a coated polarizer or a polarizing plate.

The polarization layer 210 may be directly bonded to the one surface of the window substrate 230 or may be attached through the first adhesive layer 220 . The touch sensor 200 may be coupled to the polarization layer 210 through the second adhesive layer 225 .

As shown in FIG. 5 , the window substrate 230 , the polarization layer 210 , and the touch sensor 200 may be sequentially disposed from the user's viewing side. In this case, since the sensing electrodes of the touch sensor 200 are disposed under the polarization layer 210 , it is possible to more effectively prevent the sensing electrode from being viewed.

In an embodiment, the touch sensor 200 may be directly transferred onto the window substrate 230 or the polarization layer 210 . In an embodiment, the window substrate 230 , the touch sensor 200 , and the polarization layer 210 may be disposed in the order from the user's viewing side.

Hereinafter, preferred embodiments are presented to help the understanding of the present invention, but these examples are merely illustrative of the present invention and do not limit the appended claims, and are within the scope and spirit of the present invention. It is obvious to those skilled in the art that various changes and modifications are possible, and it is natural that such variations and modifications fall within the scope of the appended claims.

Examples and Comparative Examples

A polyimide film having the physical properties shown in Table 1 below was used as the base layer and the support layer.

PI(A) and PI(B) were used by removing the copper foil from the copper-clad laminate manufactured by Innox and taking out the polyimide film.

PI(A) PI(B) PI(I) PI(II) PI(III) thickness 12㎛ 25㎛ 35㎛ 25㎛ 25㎛ Modulus of elasticity (GPa) 3.8 4.1 6.9 6.7 2.0 Tensile breaking strength (MPa) 163 156 369 348 189 Tensile Yield Strength (MPa) 130 121 168 173 145 Elongation (%) 51.5 46.4 38.1 32.4 79.8 PI(I): (Product name: GLA, Manufacturer: SKC)
PI(II): (Product name: GLA, Manufacturer: SKC)
PI(III): (Product name: GV, Manufacturer: SKC)
Elastic Modulus Measurement Standard: ASTM D882, IPC-TM-650 2.4.19
(12.7*140mm, 50.8mm/min, measuring gage distance 102mm)
Tensile Breaking Strength, Tensile Yield Strength Measurement Standard: Same as above
Elongation Measurement Standard: Same as above

Among the polyimide films shown in Table 1, the base layer and the support layer were selected as shown in Table 2 and bonded using a PSA adhesive layer (thickness, 15 µm).

Thereafter, a digitizer including a conductive coil of the form shown in FIGS. 1 to 3 is formed by forming a lower conductive layer with a thickness of 15 μm on the base layer, and an upper conductive layer with a thickness of 5 μm and an acrylic interlayer insulating layer. formed.

Among the polyimide films listed in Table 1, a lower conductive layer with a thickness of about 12 μm is formed on the base layer, and an upper conductive layer with a thickness of about 0.7 μm and an acrylic interlayer insulating layer are used to form the form shown in FIGS. A digitizer including a conductive coil was manufactured. A support layer was selected as described in Table 2 on the base layer and was bonded using a PSA adhesive layer (thickness, 15 μm).

base layer support layer Example 1 PI(A) PI(I) Example 2 PI(B) PI(I) Example 3 PI(A) PI(II) Example 4 PI(B) PI(II) Example 5 PI(A) PI(B) Example 6 PI(B) PI(B) Comparative Example 1 PI(A) PI(III) Comparative Example 2 PI(B) PI(III) Comparative Example 3 PI(A) - Comparative Example 4 PI(B) -

Flexural reliability evaluation

It was determined whether the digitizer sensing function was actually implemented while repeating the bending test of the curvature of 1.5R using the bending evaluation jig for the digitizers of Examples and Comparative Examples. Specifically, when the resistance of about 5 ohms was measured when the resistance was measured with a multimeter (manufactured by Fluke, 2074974), it was determined that the digitizer sensing performance was substantially implemented.

The evaluation results are shown in Table 3. Specifically, when the digitizer sensing is implemented at the number of bends, "OK" is indicated, and when the sensing fails, "NG" is indicated.

number of bends
(K: 1000) 30K 60K 90K 120K 150K Example 1 OK OK OK OK NG Example 2 OK OK OK OK OK Example 3 OK OK OK NG - Example 4 OK OK OK NG - Example 5 OK OK NG - - Example 6 OK OK NG - - Comparative Example 1 OK NG - - - Comparative Example 2 OK NG - - Comparative Example 3 NG - - - - Comparative Example 4 NG - - - -

Referring to Table 3, significantly improved bending reliability was obtained in the digitizer including the support layer satisfying the thickness and elastic modulus according to the exemplary embodiments. In Example 5 in which the breaking strength/yield strength of the support layer was smaller than that of the base layer and Example 6 in which the same support layer as the base layer was used, the bending durability was somewhat lowered compared to Examples 1 to 4.

50: first conductive coil 70: second conductive coil
90: support layer 100: digitizer
105: base layer 110: lower conductive line
120: interlayer insulating layer 122: first interlayer insulating layer
124: second interlayer insulating layer 130: upper conductive line
135, 137: contact 140: passivation layer

Claims (17)

base layer;
a lower conductive layer disposed on the upper surface of the base layer;
an interlayer insulating layer formed on the upper surface of the base layer and covering the lower conductive layer;
an upper conductive layer disposed on the interlayer insulating layer; and
A support layer coupled on the bottom surface of the base layer and having a thickness equal to or greater than the thickness of the base layer and an elastic modulus equal to or greater than the elastic modulus of the base layer,
The elastic modulus of the base layer is 2 to 6 GPa, and the elastic modulus of the support layer is 4 to 10 GPa, a digitizer. The digitizer of claim 1, wherein the thickness of the support layer is greater than the thickness of the base layer, and the elastic modulus of the support layer is greater than the elastic modulus of the base layer. The method according to claim 2, The ratio of the elastic modulus of the support layer to the elastic modulus of the base layer is 1.5 to 2, the digitizer. delete The method according to claim 1, wherein the tensile rupture strength of the support layer is greater than the tensile rupture strength of the base layer. wherein the tensile yield strength of the support layer is greater than the tensile yield strength of the base layer. The digitizer according to claim 1, wherein the elongation of the support layer is smaller than the elongation of the base layer. The digitizer of claim 1 , wherein the base layer and the support layer include the same type of organic material. The digitizer of claim 7 , wherein the base layer and the support layer include a polyimide-based material. The digitizer of claim 1, further comprising an adhesive layer formed between the support layer and the base layer. The method according to claim 1, wherein the lower conductive layer comprises a plurality of first lower conductive lines and a plurality of second lower conductive lines extending in a second direction parallel to the upper surface of the base layer,
The upper conductive layer is parallel to the upper surface of the base layer and includes a plurality of first upper conductive lines and a plurality of second upper conductive lines extending in a first direction perpendicular to the second direction, the digitizer. 11. The method of claim 10,
first contacts electrically connecting the first upper conductive lines and the second lower conductive lines to form a first conductive coil; and
and second contacts electrically connecting the first lower conductive lines and the second upper conductive lines to form a second conductive coil. The method according to claim 11, wherein the first conductive coil extends in the first direction, a plurality of the first conductive coils are arranged along the second direction,
The second conductive coil extends in the second direction, and a plurality of the second conductive coils are arranged along the first direction. The digitizer of claim 10, wherein the base layer includes a bending region in a central portion. The digitizer of claim 13 , wherein a bending axis of the bending region intersects the first upper conductive line and is parallel to the first lower conductive line. display panel; and
An image display device comprising the digitizer according to claim 1 disposed below the display panel. The image display device of claim 15 , further comprising a touch sensor disposed on the display panel. The method according to claim 16, further comprising a rear cover and a window substrate,
The touch sensor is disposed between the window substrate and the display panel, and the digitizer is disposed between the display panel and the rear cover.

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