KR20240136730A - Digitizer and image display device including the same - Google Patents

Abstract

Embodiments of the present invention provide a digitizer and an image display device including the same. The digitizer includes a substrate layer having first and second surfaces facing each other and including a convex portion and a recessed portion formed on a side of the first surface, a lower conductive layer formed on the second surface of the substrate layer, an interlayer insulating layer formed on the lower conductive layer, and an upper conductive layer formed on the interlayer insulating layer and electrically connected to the lower conductive layer.

Description

Digitizer and image display device including the same {DIGITIZER AND IMAGE DISPLAY DEVICE INCLUDING THE SAME}

The present invention relates to a digitizer and an image display device including the same. More specifically, the present invention relates to a digitizer including a double-layer conductive structure and an image display device including the same.

Recently, various sensing functions and communication functions have been combined with image display devices and implemented in the form of, for example, smartphones. For example, electronic devices are being developed in which a touch panel or touch sensor is attached to the display panel of the image display device and information input functions are implemented by selecting a menu displayed on the window surface.

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

For example, compared to touch sensors or touch panels that utilize capacitance, digitizers utilize electromagnetic induction and include thicker conductive lines.

Accordingly, the upper copper-clad laminate and the lower copper-clad laminate are patterned separately according to the circuit design of each layer and then laminated onto a resin substrate to manufacture a digitizer. In this case, a via hole process is performed to align and connect the upper copper wiring and the lower copper wiring.

In addition, flexible displays that can be folded or bent have recently been developed, and accordingly, sensor structures such as the digitizer also need to be developed to have appropriate properties, design, and structure so that they can be applied to flexible displays.

As described above, a digitizer having a relatively large thickness may be vulnerable to cracking and lifting of wiring when folding stress is applied in the folding area of a flexible display, and damage to the resin substrate may also occur.

Korean Patent Publication No. 10-1750564

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

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

1. A digitizer comprising: a substrate layer having first and second surfaces facing each other and including a convex portion and a recessed portion formed on a side of the first surface; a lower conductive layer formed on the second surface of the substrate layer; an interlayer insulating layer formed on the lower conductive layer; and an upper conductive layer formed on the interlayer insulating layer and electrically connected to the lower conductive layer.

2. A digitizer in the above 1, wherein a plurality of the convex portions and the recessed portions are alternately and repeatedly arranged on the first surface of the substrate layer.

3. A digitizer in the above 1, wherein the substrate layer includes a hole formed around the recessed portion.

4. In the above 3, the hole is a digitizer that extends from the first surface of the substrate layer and partially penetrates the substrate layer.

5. In the above 3, the digitizer extends from the first surface of the substrate layer to the second surface.

6. In the above 3, the digitizer is formed between the convex portion and the recessed portion.

7. A digitizer in the above 3, wherein a plurality of said holes are formed around the periphery of the recessed portion.

8. A digitizer further comprising a filling layer filling the hole in the above 3.

9. In the above 3, the filling layer is a digitizer having a lower elasticity than the substrate layer.

10. A digitizer according to 9 above, wherein the substrate layer comprises polyimide, and the filling layer comprises an organic insulating layer different from the substrate layer.

11. In the above 1, 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 second surface of the substrate layer,

A digitizer, wherein the upper conductive layer comprises a plurality of first upper conductive lines and a plurality of second upper conductive lines extending in a first direction that is parallel to the second surface of the substrate layer and perpendicular to the second direction.

12. A digitizer including, in the above 11, first contacts electrically connecting the first upper conductive lines and the second lower conductive lines and forming a first conductive coil; and second contacts electrically connecting the first lower conductive lines and the second upper conductive lines and forming a second conductive coil.

13. A digitizer according to the above 12, wherein the first conductive coil extends in the first direction and 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.

14. In the above 13, the substrate layer includes a folding area,

A digitizer wherein the folding axis of the above folding region intersects the first upper conductive line and is parallel to the first lower conductive line.

15. An image display device comprising a display panel; and a digitizer according to the above-described embodiments disposed under the display panel.

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

17. In the above 16, further including a rear cover and a window substrate,

An image display device, wherein 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.

18. An image display device according to the above 17, further comprising a point adhesive layer that bonds the first surface of the digitizer and the lower surface of the display panel to each other.

According to embodiments of the present invention, the bottom surface of the substrate layer of the digitizer may include convex portions and may include recessed portions between the convex portions. When the digitizer is folded/bent, the tensile stress/compressive stress applied to the substrate layer may be buffered/relieved through the recessed portions, and further, the tensile stress/compressive stress may be spread through the convex portions. Accordingly, it is possible to prevent defects such as lifting, peeling, and cracking of conductive lines due to folding/bending.

The lower surface of the above-described substrate layer can be combined with the display panel. Accordingly, the folding/bending stress applied to the display panel can be first diffused, alleviated, or absorbed at the lower surface of the substrate layer. Accordingly, peeling or breakage of the substrate layer occurring at the interface between the display panel and the digitizer can be prevented.

In some embodiments, a hole can be formed in the recessed portion of the substrate layer. Accordingly, the flexible properties of the recessed portion can be further improved, and folding/bending stress can be at least partially removed through the hole.

The above digitizer includes a plurality of first conductive coils and second conductive coils, and the first conductive coils and second conductive coils may include a plurality of conductive loops. Accordingly, a digitizer promoting an electromagnetic induction phenomenon and having high resolution and improved flexible characteristics can be provided.

FIG. 1 is a schematic cross-sectional diagram illustrating a digitizer according to exemplary embodiments.
FIGS. 2 to 4 are schematic cross-sectional views illustrating a digitizer according to some exemplary embodiments.
FIG. 5 is a schematic cross-sectional diagram illustrating a digitizer according to exemplary embodiments.
FIGS. 6 and 7 are schematic plan views illustrating challenge coils included in a digitizer according to exemplary embodiments.
FIG. 8 is a schematic plan view illustrating a digitizer according to exemplary embodiments.
FIGS. 9 to 11 are flowcharts illustrating a method of manufacturing a digitizer according to exemplary embodiments.
FIG. 12 is a schematic cross-sectional view showing an image display device according to exemplary embodiments.

Embodiments of the present invention provide a digitizer having improved electrical characteristics and folding reliability, including a substrate layer and a multi-layered conductive structure. In addition, an image display device including the digitizer is provided.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. However, the following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the contents of the invention described above, so the present invention should not be interpreted as being limited to matters described in such drawings.

In the drawings below, two directions that are parallel to and intersect the upper surface of the digitizer (100) or substrate layer (105) are defined as the first direction and the second direction. For example, the first direction and the second direction may intersect each other perpendicularly.

The above first direction may correspond to the width direction, row direction or X-direction of the digitizer (100). The above second direction may correspond to the length direction, column direction or Y-direction of the digitizer (100).

FIG. 1 is a schematic cross-sectional view showing a digitizer according to exemplary embodiments. FIG. 1 is a cross-sectional view schematically showing a laminated structure of a digitizer. The structure and interconnection of the lower conductive layer (110) and the upper conductive layer (130) included in the digitizer (100) are described in detail later with reference to FIGS. 5 to 8.

Referring to FIG. 1, the digitizer (100) may include a lower conductive layer (110) and an upper conductive layer (130) formed on a substrate layer (105). The lower conductive layer (110) and the upper conductive layer (130) may be spaced apart from each other in different layers with an interlayer insulating layer (120) therebetween. The lower conductive layer (110) and the upper conductive layer (130) may be sequentially laminated from the upper surface of the substrate layer (105).

The substrate layer (105) is used to encompass a support layer or film-type substrate for forming conductive layers (110, 130) and an interlayer insulating layer (120). For example, the substrate 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), polyallylate, polyimide (PI), cellulose acetate propionate (CAP), polyether sulfone (PES), cellulose triacetate (TAC), polycarbonate (PC), cyclic olefin copolymer (COC), polymethyl methacrylate (PMMA), etc.

Preferably, the substrate layer (105) may include polyimide to secure stable bending characteristics.

According to exemplary embodiments, 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) may include 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 or more thereof.

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

The interlayer insulating layer (120) may include an organic insulating material such as an epoxy resin, an acrylic resin, a siloxane resin, a polyimide resin, or the like, or an inorganic insulating material such as silicon oxide, silicon nitride, or the like. Preferably, the interlayer insulating layer (120) may be formed using an organic insulating material to improve flexibility characteristics.

A 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 resin, an acrylic resin, a siloxane resin, a polyimide resin, or the like, or an inorganic insulating material such as silicon oxide, silicon nitride, or the like.

Preferably, the passivation layer (140) may be formed using an organic insulating material to improve the flexibility characteristics. In one embodiment, 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 the folding characteristics and may include the organic insulating material.

In one embodiment, each of the interlayer insulating layer (120) and the passivation layer (140) may include the inorganic insulating material and may have a thickness of about 100 nm to 500 nm.

In some embodiments, the thickness of the upper conductive layer (130) may be smaller than the thickness of the lower conductive layer (110). For example, the lower conductive layer (110) having a thick film structure may reduce the overall resistance of the digitizer (100), thereby increasing the sensor sensitivity through promotion of the electromagnetic induction phenomenon. In addition, the flexibility and folding reliability of the digitizer (100) may be improved through the upper conductive layer (130) having a relatively thin film structure.

In some embodiments, the thickness of the lower conductive layer (110) may be about 5 to 30 μm, preferably about 10 to 25 μm. The thickness of the upper conductive layer (130) may be 6 μm or less, preferably about 1 to 6 μm, or about 1 to 5 μm.

The substrate layer (105) may include a first surface (105a) and a second surface (105b) that face each other. The first surface (105a) and the second surface (105b) may correspond to the lower surface and the upper surface of the substrate layer (105), respectively. The lower conductive layer (110), the interlayer insulating layer (120), and the upper conductive layer (130) described above may be sequentially laminated on the second surface (105b) of the substrate layer (105).

According to embodiments of the present invention, the substrate layer (105) may include convex portions (101) formed on the first surface (105a). The convex portions (101) may have a shape that protrudes in a direction opposite to the direction toward the conductive layers (110, 130) from the first surface (105a) in FIG. 1.

According to exemplary embodiments, a recessed portion (103) may be formed between the convex portions (101). The recessed portion (103) may have a concave shape defined by the convex portions (101).

In some embodiments, the convex portions (101) and the recessed portions (103) may be alternately and repeatedly arranged.

In one embodiment, the convex portions (101) and the recessed portions (103) can be repeatedly arranged along either the first direction or the second direction (see FIG. 3).

In one embodiment, the convex portions (101) and the recessed portions (103) may be repeatedly arranged along the first direction and the second direction. In this case, the convex portions (101) may have an emboss pattern shape.

The convex portions (101) and recessed portions (103) can absorb or spread the folding/bending stress applied from the substrate layer (105).

For example, when tensile stress is applied to the substrate layer (105), the tensile area of the substrate layer (105) can be increased by the recessed portions (103). Accordingly, the tensile stress can be transmitted/spread to the convex portions (101) around the recessed portions (103), and folding/stress can be distributed to the outer area of the substrate layer (105).

As described above, the folding/bending stress in the substrate layer (105) is sufficiently reduced, so that the amount of stress transmitted to the conductive layers (110, 130) can be reduced. Accordingly, mechanical failures such as peeling, cracking, and lifting of the conductive layers (110, 130) can be prevented, and the electromagnetic performance and reliability through the conductive coil described below can be improved.

As shown in Fig. 1, the surface of the convex portion (101) may have a curved shape. Accordingly, cracks on the surface of the substrate layer (105) can be prevented and folding/bending stress can be more easily spread.

FIGS. 2 to 4 are schematic cross-sectional views illustrating a digitizer according to some exemplary embodiments.

Referring to FIG. 2, the substrate layer (105) may include a hole (104a) extending from the first surface (105a).

A hole (104a) may be formed around a recessed portion (103). In some embodiments, a plurality of holes (104a) may be formed around one recessed portion (103).

In one embodiment, as illustrated in FIG. 2, a pair of holes (104a) may be formed with one recessed portion (103) interposed therebetween in the cross-sectional direction.

For example, a hole (104a) may be formed between a convex portion (101) and a recessed portion (103). In one embodiment, a plurality of holes (104a) may be arranged along a boundary between the convex portion (101) and the recessed portion (103).

As illustrated in FIG. 2, the hole (104a) may partially penetrate the substrate layer (105). The hole (104a) may extend from the first side (105a) of the substrate layer (105) and may not extend to the second side (105b).

Referring to FIG. 3, the hole (104b) may substantially completely penetrate the substrate layer (105). As illustrated in FIG. 3, the hole (104b) may extend from the first side (105a) of the substrate layer (105) to the second side (105b).

According to the embodiments described with reference to FIGS. 2 and 3, holes (104a, 104b) are formed around the recessed portion (103) to further increase the tensile length of the substrate layer (105). In addition, tensile/compressive stress may be reduced or eliminated by the holes (104a, 104b).

Accordingly, the resistance and durability of the substrate layer (105) to folding/bending stress can be further improved.

Referring to FIG. 4, a filling layer (106) may be formed within the above-described holes (104a, 104b). The filling layer (106) may have a pillar or cylinder shape.

The filling layer (106) may include a resin material having higher ductility or lower elastic modulus than the substrate layer (105). In one embodiment, the filling layer (106) may include an organic insulating layer formed of a different material from the substrate layer (105).

For example, the filling layer (106) may include an elastomer. Accordingly, the empty space created by the holes (104a, 104b) can be filled to prevent a decrease in mechanical stability, while sufficiently cushioning the folding/bending stress in the holes (104a, 104b).

FIG. 5 is a schematic cross-sectional view illustrating a digitizer according to exemplary embodiments. FIGS. 6 and 7 are schematic plan views illustrating conductive coils included in a digitizer according to exemplary embodiments. For example, FIG. 5 is a cross-sectional view taken along the line I-I' shown in FIG. 6 in the thickness direction.

Detailed descriptions of materials, structures and configurations that are substantially the same as or similar to those described with reference to FIGS. 1 to 4 are omitted.

Referring to FIG. 5, as described above, the digitizer (100) may include a lower conductive layer (110) and an upper conductive layer (130) formed on a substrate layer (105). The lower conductive layer (110) and the upper conductive layer (130) may be spaced apart from each other in different layers with an interlayer insulating layer (120) therebetween. A passivation layer (140) may be formed on the interlayer insulating layer (120) to cover the upper conductive layer (130).

The lower portion of the substrate layer (105) may include convex portions (101) and recessed portions (103), as described with reference to FIG. 1. The substrate layer (105) may include holes (104a, 104b), as described with reference to FIGS. 2 to 4, and a filling layer (106) may be formed within the holes (104a, 104b).

Referring to FIGS. 6 and 7, a digitizer (100) according to exemplary embodiments may include a first conductive coil (50) and a second conductive coil (70).

The first challenge coil (50) and the second challenge coil (70) can be defined by combining the lower challenge layer (110) and the upper challenge layer (130) with contacts (135, 137).

The lower conductive layer (110) may include a first lower conductive line (112) (see FIG. 7) and a second lower conductive line (114) (see FIG. 6). For example, the second lower conductive line (114) may be shorter than the first lower conductive line (112).

The lower challenge lines (112, 114) can be formed by patterning using a photolithography process after the lower challenge layer (110) is formed, as shown in FIG. 1.

The upper conductive layer (130) may include a first upper conductive line (132) (see FIG. 6) and a second upper conductive line (134) (see FIG. 7). For example, the second upper conductive line (134) may be shorter than the first upper conductive line (132).

The upper challenge lines (132, 134) can be formed by patterning using a photolithography process after the upper challenge layer (130) is formed, as shown in FIGS. 1 to 4.

The first lower challenge line (112) and the second lower challenge line (114) can extend in the second direction. The first upper challenge line (132) and the second upper challenge line (134) can extend in the first direction.

As illustrated in FIG. 6, 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) can be coupled to each other to form a first conductive coil (50).

The first upper challenge line (132) and the second lower challenge line (114) together form the first challenge coil (50) and can be provided together as a sensing line for the input pen through electromagnetic induction.

For example, a first upper conductive line (132) and a second lower conductive line (114) may be electrically connected to each other through a first contact (135). A plurality of first upper conductive lines (132) and a plurality of second lower conductive lines (114) may be electrically connected to each other through a plurality of first contacts (135) so that a plurality of conductive loops may be included in one first conductive coil (50). 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 the planar direction. The first contact (135) may be formed substantially integrally with the first upper conductive line (132) by penetrating the interlayer insulating layer (120).

A first input line (113) and a first output line (115) may be connected to a first challenge loop of any one of the first challenge loops. For example, the first input line (113) may be connected to a first challenge loop that is the innermost among the first challenge loops. The first output line (115) may be connected to a first challenge loop that is the outermost among the first challenge loops.

The current input from the first input line (113) alternately circulates through the lower conductive layer (110) and the upper conductive layer (130) through the first conductive loops, and can be discharged through the first output line (115).

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 connecting line (114a). For example, neighboring first conductive loops may be connected by the first internal connecting line (114a).

As illustrated in FIG. 7, 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) can be coupled to each other to form a second conductive coil (70).

The first lower challenge line (112) and the second upper challenge line (134) together form a second challenge coil (70) and can be provided together as a sensing line for the input pen through electromagnetic induction.

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) may be electrically connected to each other through the plurality of second contacts (137) so that a plurality of conductive loops may be included in one second conductive coil (70). For example, four second conductive loops may be included in one second conductive coil (70).

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

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

The current input from the second input line (117) alternately circulates through the lower conductive layer (110) and the upper conductive layer (130) through the second conductive loops, and can be discharged through the second output line (119).

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 via the second conductive loop and the second contact (137) by the external connection line (134a).

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

In some embodiments, the upper conductive layer (130) may further include a second internal connecting line (134b). For example, neighboring second conductive loops within the second conductive coil (70) may be connected to each other by the second internal connecting line (134b).

In FIGS. 6 and 7, four challenge loops are shown within one challenge coil, but the number of challenge loops within the challenge coil can be adjusted in consideration of the size and resolution of the image display device.

As described with reference to FIGS. 6 and 7, the first challenge coil (50) and the second challenge coil (70) may each include a plurality of challenge loops of different sizes.

Accordingly, the strength of the magnetic field generated through the digitizer (100) can be sufficiently increased to efficiently promote energy transfer to, for example, an input pen contacting a window surface of an image display device.

In addition, since the lower conductive layer (110) and the upper conductive layer (130) are connected through contacts (135, 137) to form a conductive loop, the number of loops of the conductive coil in a limited space can be efficiently increased and the electromagnetic induction efficiency can be improved.

According to exemplary embodiments, both the lower conductive layer (110) and the upper conductive layer (130) can be disposed on the second surface (105b) of the substrate layer (105). Accordingly, the stress direction for the lower conductive layer (110) and the upper conductive layer (130) can be controlled to be the same when bending or folding through the substrate layer (105).

For example, when tensile stress is applied to the first surface (105a) of the substrate layer (105), compressive stress may be applied to the lower conductive layer (110) and the upper conductive layer (130). Accordingly, a neutral plane where stress is offset may be easily created adjacent to the conductive layers (110, 130). Accordingly, the stress applied to the conductive layers (110, 130) may be alleviated, thereby reducing or preventing electrode cracking due to bending.

As described above, 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 described below with reference to FIG. 8, the first upper conductive line (132) may extend in a first direction (e.g., row direction or width direction) and may intersect the folding axis. For example, the first upper conductive line (132) may be perpendicular to the folding axis. The first lower conductive line (112) may extend in a second direction (column direction or length direction) and may be substantially parallel to the folding axis.

According to exemplary embodiments, the thickness of the first upper conductive line (132), through which folding stress is easily transmitted as it intersects the folding axis, can be reduced to reduce or suppress crack prevention within the conductive line.

The first lower conductive line (112), which is parallel to the above folding axis and relatively free from bending stress, can be formed with a large thickness to expand the current path through the conductive coil and implement a sufficient electromagnetic induction effect.

In one embodiment, the second lower challenge line (114) may also have a greater thickness than the second upper challenge line (134).

Fig. 8 is a schematic plan view showing a digitizer according to exemplary embodiments. For convenience of explanation, the detailed structure/configuration of the conductive coil is omitted in Fig. 8.

Referring to FIG. 8, a plurality of first conductive coils (50) and second conductive coils (70) can be arranged on the upper surface of the substrate layer (105).

The first challenge coil (50) can extend in the first direction or row direction. A plurality of first challenge coils (50) can be arranged along the second direction or 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). In some embodiments, neighboring first conductive coils (50-1 to 50-n) may be sequentially arranged so as to partially overlap each other in a planar direction along the second direction.

The second challenge coil (70) can extend in the second direction or the column direction. A plurality of second challenge coils (70) can be arranged along the first direction or the row direction.

For example, m second conductive coils (70-1 to 70-m) may be arranged sequentially along the first direction. In some embodiments, neighboring second conductive coils (70-1 to 70-m) may be arranged sequentially while partially overlapping each other in a planar direction along the first direction.

The central portion of the substrate layer (105) may include a folding area (FA). A folding axis (80) extending in the second direction may be positioned within the folding area (FA). The digitizer (100) according to exemplary embodiments may be bent or folded around the folding axis (80).

As described with reference to FIGS. 1 to 4, the lower portion of the substrate layer (105) includes convex portions (101) and recessed portions (103), and stress due to folding/bending can be absorbed or dispersed from the substrate layer (105).

Accordingly, the mechanical and electrical reliability of the digitizer (100) according to embodiments of the present invention in which the challenge coils and the challenge coils are arranged in a repetitive manner while overlapping each other can be efficiently implemented.

As described above, the thickness of the first upper conductive line (132) or the second upper conductive line (134) intersecting the folding axis (80) can be relatively small. Accordingly, cracking of the upper conductive layer (130) to which bending stress is directly applied can be prevented and flexibility can be increased.

The thickness of the first lower conductive line (112) and the second lower conductive line (114), which are parallel to the folding axis (80) and have relatively small bending stress, can be increased to reduce resistance and improve the efficiency of generating a magnetic field through the conductive coil.

FIGS. 9 and 10 are flowcharts illustrating a method of manufacturing a digitizer according to exemplary embodiments.

Referring to FIG. 9, a substrate layer (105) including a convex portion (101) and a recessed portion (103) can be formed (e.g., step S10).

According to exemplary embodiments, a polyimide precursor composition may be applied on a molding substrate having a groove formed corresponding to a convex portion (101), and then cured to form a substrate layer (105) including a convex portion (101) (e.g., step S10).

The above polyimide precursor composition may include a polyamic acid composition.

In some embodiments, a copper foil may be attached to the second surface (105b) of the substrate layer (105) and cured together. Accordingly, a substrate layer (105) may be formed in the form of a cross-sectional copper foil laminate, and convex portions (101) may be formed on the first surface (105a).

In some embodiments, a hole (104a) can be formed through the first surface (105a) of the cured substrate layer (105). The hole (104a) can partially penetrate the substrate layer (105).

In some embodiments, a resin composition may be filled into the hole (104a) to form a filling layer (106).

A digitizer process can be performed from the second side (105b) of the substrate layer (105) (e.g., step S20).

According to exemplary embodiments, a lower conductive layer (110) may be formed on the second surface (105b) of the substrate layer (105), for example, through a copper plating process. The lower conductive layer (110) may be etched to form lower conductive lines (112, 114).

As described above, when the substrate layer (105) is provided in the form of a cross-sectional copper-clad laminate, the copper layer provides a lower conductive layer (110), and the copper layer can be etched to form lower conductive lines (112, 114).

Thereafter, an interlayer insulating layer (120) covering the lower conductive lines (112, 114) can be formed. An upper conductive layer (130) can be formed on the interlayer insulating layer (120) through a deposition process, such as a sputtering process, for example. The upper conductive layer (110) can be etched to form contacts (135, 137) and upper conductive lines (132, 134).

In some embodiments, a passivation layer (140) may be further formed on the interlayer insulating layer (120) to cover the upper conductive lines (132, 134).

Referring to FIG. 10, after performing the digitizer process indicated at step S20, a hole (104a, 104b) may be formed through the first surface (105a) of the substrate layer (105) (e.g., step S30).

For example, the holes (104a, 104b) can be formed using a laser or a drill (e.g., a CNC (computer numerical control) drill).

As holes (104a, 104b) are formed after the etching process and deposition process of the conductive layers, the stability of the digitizer process described above can be secured. For example, when a hole (104b) extending to the second surface (105b) is formed, conductive layer deposition defects, conductive layer peeling, etc. in the hole (104b) can be avoided.

Referring to FIG. 11, a substrate layer (105) can be prepared (e.g., step S05). The substrate layer (105) can have a substantially smooth first side and a second side.

Thereafter, for example, at step S20, the digitizer process described above can be performed on the second surface (105b) of the substrate layer (105).

Convex portions (101) and recessed portions (103) can be formed on the first surface (105a) of the substrate layer (105) on which the digitizer structure is formed.

According to exemplary embodiments, heat and pressure may be applied to the first surface (105a) of the substrate layer (105) through a hot press process to form convex portions (101) and recessed portions (103).

In some embodiments, the hot press process may be used to apply heat and pressure to the first surface (105a) of the substrate layer (105) prior to the digitizer process to form convex portions (101) and recessed portions (103).

FIG. 12 is a schematic cross-sectional view showing an image display device according to exemplary embodiments.

Referring to FIG. 12, the image display device may include a display panel (360), a touch sensor (200), and a digitizer (100) according to the exemplary embodiments described above.

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

The digitizer (100) includes relatively thick conductive lines for the purpose of generating a magnetic field efficiently using the electromagnetic induction phenomenon, and may include a plurality of conductive coils. Accordingly, the digitizer (100) may be placed under the display panel (360) so as not to be visible to the user of the image display device.

As described above, by utilizing the structure of the digitizer (100) according to the exemplary embodiments, the magnetic field strength can be sufficiently increased to efficiently enhance energy transfer to an input pen contacting, for example, a window substrate (230) of an image display device.

According to exemplary embodiments, the digitizer (100) may be placed on the back surface of the image display device, or under the display panel (360). Accordingly, the conductive lines included in the digitizer (100) may not be visible to the user. Accordingly, each of the conductive lines included in the digitizer (100) may be formed as a solid line including the above-described metal without employing a mesh structure to improve transmittance.

Therefore, sufficient current path can be secured by the above-mentioned challenge line to enhance electromagnetic induction efficiency.

The digitizer (100) can be attached or coupled to the display panel (360) via the first adhesive layer (150). According to exemplary embodiments, the first surface (105a) of the substrate layer (105) of the digitizer (100) can be attached to the bottom surface of the panel substrate (300) via the first adhesive layer (150).

Since the first surface (105a) includes convex portions (101) and recessed portions (103), the bonding area with the first point-adhesive layer (150) can be increased. Accordingly, peeling of the substrate layer (105) can be suppressed during folding/bending. In addition, since the folding/bending stress is reduced by the convex portions (101) and recessed portions (103), defects such as cracks, lifting, and interlayer bubbles in the substrate layer (105) can be prevented.

The display panel (360) may include a pixel electrode (310), a pixel defining film (320), a display layer (330), a counter electrode (340), and an encapsulation layer (350) arranged on a panel substrate (300).

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

A pixel defining film (320) may be formed on the insulating film to expose the pixel electrode (310) and 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 arranged on the pixel definition film (320) and the display layer (330). The counter electrode (340) may be provided as, for example, a common electrode or cathode of an image display device. An encapsulation layer (350) for protecting the display panel (360) may be laminated on the counter electrode (340).

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

The above sensing electrodes or sensing channels are each independently arranged within a single layer and can interact with adjacent sensing electrodes or sensing channels to generate electrostatic capacitance.

The touch sensor (200) can be combined with the display panel (360) through the second point adhesive layer (260).

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

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

The polarizing layer (210) may be directly bonded to the above-mentioned surface of the window substrate (230) or may be attached through the third point-adhesive layer (220). The touch sensor (200) may be bonded to the polarizing layer (210) through the fourth point-adhesive layer (225).

As shown in Fig. 12, the window substrate (230), the polarizing layer (210), and the touch sensor (200) can be arranged in that order from the user's viewing side. In this case, since the sensing electrodes of the touch sensor (200) are arranged under the polarizing layer (210), the phenomenon of the sensing electrodes being visible can be prevented more effectively.

In one embodiment, the touch sensor (200) may be directly transferred onto the window substrate (230) or the polarizing layer (210). In one embodiment, the window substrate (230), the touch sensor (200), and the polarizing layer (210) may be arranged in this order from the user's viewing side.

50: 1st challenge coil 70: 2nd challenge coil
100: Digitizer 101: Convex
103: Recessed part 104a, 104b: Hole
105: Base layer 106: Filling layer
110: Lower challenge layer 112: First lower challenge line
114: Second lower challenge line 120: Interlayer insulation layer
130: Upper challenge layer 132: First upper challenge line
134: 2nd upper challenge line 135: 1st contact
137: Second contact 140: Passivation layer

Claims (18)

A substrate layer having first and second surfaces facing each other and including a convex portion and a recessed portion formed on the first surface side;
A lower conductive layer formed on the second surface of the above substrate layer;
An interlayer insulating layer formed on the lower conductive layer; and
A digitizer comprising an upper conductive layer formed on the interlayer insulating layer and electrically connected to the lower conductive layer. A digitizer according to claim 1, wherein a plurality of the convex portions and the recessed portions are alternately and repeatedly arranged on the first surface of the substrate layer. A digitizer according to claim 1, wherein the substrate layer includes a hole formed around the recessed portion. A digitizer according to claim 3, wherein the hole extends from the first surface of the substrate layer and partially penetrates the substrate layer. A digitizer according to claim 3, wherein the hole extends from the first surface of the substrate layer to the second surface. A digitizer according to claim 3, wherein the hole is formed between the convex portion and the recessed portion. A digitizer according to claim 3, wherein a plurality of said holes are formed around the periphery of said recessed portion. A digitizer according to claim 3, further comprising a filling layer filling the hole. A digitizer according to claim 3, wherein the filling layer has a lower elastic modulus than the substrate layer. A digitizer according to claim 9, wherein the substrate layer comprises polyimide, and the filling layer comprises an organic insulating layer different from the substrate layer. In claim 1, 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 second surface of the substrate layer,
A digitizer, wherein the upper conductive layer comprises a plurality of first upper conductive lines and a plurality of second upper conductive lines extending in a first direction that is parallel to the second surface of the substrate layer and perpendicular to the second direction. In claim 11,
First contacts electrically connecting the first upper conductive lines and the second lower conductive lines to form a first conductive coil; and
A digitizer comprising second contacts electrically connecting the first lower conductive lines and the second upper conductive lines and forming a second conductive coil. In claim 12,
The first conductive coil extends in the first direction, and a plurality of first conductive coils are arranged along the second direction.
A digitizer wherein the second conductive coil extends in the second direction and a plurality of second conductive coils are arranged along the first direction. In claim 13, the substrate layer includes a folding region,
A digitizer wherein the folding axis of the above folding region intersects the first upper conductive line and is parallel to the first lower conductive line. display panel; and
An image display device comprising a digitizer according to claim 1 disposed below the display panel. An image display device according to claim 15, further comprising a touch sensor disposed on the display panel. In claim 16, further comprising a rear cover and a window substrate,
An image display device, wherein 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. An image display device according to claim 17, further comprising a point adhesive layer that bonds the first surface of the digitizer and the lower surface of the display panel to each other.

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