Electrode connection structure, method of manufacturing same, and digital converter including same

Abstract

The embodiment of the invention provides an electrode connection structure, a manufacturing method thereof and a digital converter including the electrode connection structure. The electrode connection structure includes: a substrate layer; a lower conductive line disposed on an upper surface of the substrate layer; an interlayer insulating layer formed on an upper surface of the substrate layer to partially cover the lower conductive line and including a contact hole exposing an upper surface of the lower conductive line; and an upper conductive line disposed on the interlayer insulating layer to be electrically connected to the lower conductive line through the contact hole. The lower wire has a reduced thickness within the contact hole.

Description

Technical Field

[0001] The present invention relates to an electrode connection structure, a manufacturing method thereof and a digital converter including the electrode connection structure. More specifically, the present invention relates to an electrode connection structure including a multi-layer conductive structure, a manufacturing method thereof and a digital converter including the electrode connection structure. Background Art

[0002] In recent years, various sensing functions and communication functions have been integrated into image display devices, such as being implemented in the form of smartphones. For example, electronic devices have been developed that enable a menu displayed on a window interface to be selected by attaching a touch panel or a touch sensor to a display panel of an image display device to further implement an information input function.

[0003] In addition, as disclosed in Korean Patent No. 10-1750564, a digital converter that converts analog coordinate information into a digital signal by electromagnetic means has been arranged on the back side of an image display device.

[0004] The digitizer may include a multi-layer structure of conductive lines connected to each other via an interlayer insulating layer. The conductive lines may be electrically connected to each other through vias or contact holes.

[0005] If the contact resistance at the wire contact interface in the through hole or contact hole increases, the overall electromagnetic characteristics of the digitizer may be deteriorated. In addition, when the digitizer is folded or bent, poor connection or peeling of the wire may occur in the through hole or contact hole.

[0006] Therefore, it is necessary to improve the connection reliability of the conductive lines in the via holes or contact holes. Summary of the invention

[0007] Technical issues

[0008] An object of the present invention is to provide an electrode connection structure having improved mechanical and electrical reliability.

[0009] An object of the present invention is to provide a method of manufacturing an electrode connection structure having improved mechanical and electrical reliability.

[0010] An object of the present invention is to provide a digitizer including an electrode connection structure having improved mechanical and electrical reliability.

[0011] Technical Solution

[0012] 1. An electrode connection structure, comprising: a substrate layer; a lower conductive line arranged on an upper surface of the substrate layer; an interlayer insulating layer formed on the upper surface of the substrate layer to partially cover the lower conductive line and including a contact hole exposing the upper surface of the lower conductive line; and an upper conductive line arranged on the interlayer insulating layer and electrically connected to the lower conductive line through the contact hole, wherein the lower conductive line has a reduced thickness within the contact hole.

[0013] 2. The electrode connection structure as described in 1 above, wherein the lower conductive line includes a step portion in the contact hole.

[0014] 3. The electrode connection structure as described in 2 above, wherein the step portion includes a curved surface.

[0015] 4. The electrode connection structure as described in 2 above, wherein the step portion has a concave side wall.

[0016] 5. The electrode connection structure as described in 2 above, wherein the interlayer insulating layer has a side wall inclined at an acute angle with respect to an upper surface of the lower conductive line.

[0017] 6. The electrode connection structure as described in 1 above, wherein the thickness of the lower conductive line is greater than the thickness of the upper conductive line.

[0018] 7. The electrode connection structure as described in 1 above, wherein the lower conductive line and the upper conductive line extend in directions crossing each other.

[0019] 8. A digital converter, comprising the electrode connection structure as described in 1 above, wherein the lower wire comprises a plurality of lower wires, the upper wire comprises a plurality of upper wires, and the plurality of lower wires and the plurality of upper wires are combined with each other through the contact holes to form a plurality of conductive coils.

[0020] 9. The digitizer as described in 8 above, wherein the plurality of lower conductive lines include first and second lower conductive lines extending in a column direction, and the plurality of upper conductive lines include first and second upper conductive lines extending in a row direction.

[0021] 10. In the digital converter described in 9 above, the multiple conductive coils include: a first conductive coil formed by connecting the first upper conductive wire and the second lower conductive wire to each other; and a second conductive coil formed by connecting the first lower conductive wire and the second upper conductive wire to each other.

[0022] 11. The digital converter as described in 10 above, wherein the first conductive coil extends along the row direction, and a plurality of the first conductive coils are arranged along the column direction; the second conductive coil extends along the column direction, and a plurality of the second conductive coils are arranged along the row direction.

[0023] 12. The digitizer as described in 8 above, wherein the substrate layer includes a folding region, and a folding axis of the folding region intersects the upper conductive line and is parallel to the lower conductive line.

[0024] 13. A method for manufacturing an electrode connection structure, comprising: forming a lower conductive line on a substrate layer; forming an interlayer insulating layer including a contact hole on the substrate layer, wherein the contact hole partially exposes the upper surface of the lower conductive line; reducing the thickness of the portion of the lower conductive line exposed by the contact hole by soft etching; and forming an upper conductive line filling the contact hole on the interlayer insulating layer.

[0025] 14. The method for manufacturing an electrode connection structure as described in 13 above, wherein forming the lower conductive line on the base layer comprises: preparing a laminated substrate including a base layer and a metal layer; and removing a surface portion of the metal layer by preliminary soft etching.

[0026] 15. The method for manufacturing an electrode connection structure as described in 14 above, wherein the preliminary soft etching includes removing a rust-proof material or an oxidation material included on the surface of the metal layer.

[0027] 16. The method for manufacturing an electrode connection structure as described in 13 above, wherein the soft etching includes removing metal residues or insulating residues on the surface of the lower conductive line exposed by the contact hole.

[0028] Effects of the Invention

[0029] In the electrode connection structure according to the embodiment of the present invention, the portion of the lower conductive line exposed by the contact hole may have a reduced thickness. For example, the portion of the lower conductive line in the contact hole (contact portion) may include a step portion or a recessed portion.

[0030] Therefore, the contact area or adhesion of the upper conductive line and the lower conductive line in the contact hole can be increased. Therefore, even when bending / folding stress is applied, the electrode connection reliability in the contact hole can be improved.

[0031] According to an exemplary embodiment, the contact portion of the lower conductive line can be formed by partially etching the lower conductive line by soft etching. The oxidation / corrosion residue of the conductive material can be removed from the contact portion by soft etching, and the insulating layer residue can also be removed at the same time. Therefore, the contact resistance at the contact portion can be reduced, thereby promoting the flow of current through the electrode connection structure.

[0032] By adopting the electrode connection structure in the conductive coil of the digitizer, the electromagnetic induction phenomenon is amplified, thereby providing a digitizer having high resolution and improved flexibility characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic cross-sectional view illustrating an electrode connection structure according to an exemplary embodiment.

[0034] Figure 2 is a partially enlarged cross-sectional view illustrating a lower conductive line in a contact hole according to an exemplary embodiment.

[0035] Figure 3 is a process flow chart illustrating a method of manufacturing an electrode connection structure according to an exemplary embodiment.

[0036] Figure 4 and Figure 5 is a cross-sectional view illustrating a method of manufacturing an electrode connection structure according to an exemplary embodiment.

[0037] Figure 6 and Figure 7 ] are SEM images showing the lower conductive line surface before soft etching and the lower conductive line surface after soft etching, respectively.

[0038] Figure 8 is a schematic cross-sectional view illustrating a digitizer according to an exemplary embodiment.

[0039] Fig. 9 and Fig.10 is a schematic plan view illustrating a conductive coil included in a digitizer according to an exemplary embodiment.

[0040] Fig.11 is a schematic plan view illustrating a digitizer according to an exemplary embodiment.

[0041] Fig.12 is a schematic cross-sectional view illustrating an image display device according to an exemplary embodiment. DETAILED DESCRIPTION

[0042] Embodiments of the present invention provide an electrode connection structure including a conductive line of a multilayer structure and having improved electrical connection reliability and a method for manufacturing the same. In addition, embodiments of the present invention provide a digitizer including the electrode connection structure.

[0043] Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. However, the accompanying drawings attached to this specification are intended to illustrate preferred embodiments of the present invention, and together with the aforementioned invention content, are used to help better understand the technical concept of the present invention, so the present invention should not be interpreted as being limited to the contents recorded in these drawings.

[0044] The terms "row direction", "column direction", etc. used in this application do not refer to absolute directions, but should be understood as relative meanings that specify directions that are different from each other. The terms "upper", "lower", etc. used in this application do not specify absolute positions, but are intended to be relative meanings used to distinguish different levels.

[0045] Figure 1 is a schematic cross-sectional view illustrating an electrode connection structure according to an exemplary embodiment.

[0046] Reference Figure 1 The electrode connection structure may include a lower conductive line 110 and an upper conductive line 130 formed on the substrate layer 105. The lower conductive line 110 and the upper conductive line 130 may be divided into different layers with the interlayer insulating layer 120 interposed therebetween.

[0047] The substrate layer 105 is intended to cover a support layer or a film-type base material for forming the conductors 110 and 130 and the interlayer insulating layer 120. For example, the substrate layer 105 may include a polymer suitable for a flexible display. Examples of the polymer may include cycloolefin 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), cycloolefin copolymer (COC), polymethyl methacrylate (PMMA), etc.

[0048] Preferably, the base material layer 105 may include polyimide to ensure stable bending characteristics.

[0049] The lower conductive line 110 and the upper conductive line 130 may both contain a low resistance metal. For example, the lower conductive line 110 and the upper conductive line 130 may contain 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.

[0050] Preferably, the lower conductive line 110 and the upper conductive line 130 may include copper or a copper alloy to achieve low resistance.

[0051] The lower conductive line 110 may be disposed on the upper surface of the substrate layer 105. The lower conductive line 110 may directly contact the upper surface of the substrate layer 105.

[0052] The interlayer insulating layer 120 may be formed on the upper surface of the base material layer 105 to partially cover the lower conductive line 110. The interlayer insulating layer 120 may include an organic insulating material such as epoxy resin, acrylic resin, siloxane resin, or polyimide 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 flexibility.

[0053] The interlayer insulating layer 120 may include a contact hole 125. An upper surface of the lower conductive line 110 may be partially exposed through the contact hole 125.

[0054] According to an exemplary embodiment, a portion of the lower conductive line 110 exposed by the contact hole 125 (hereinafter referred to as a contact portion) may have a reduced thickness. For example, a height of a bottom surface of the contact hole 125 (e.g., a height from a top surface of the substrate layer 105) may be less than a height of a top surface of the lower conductive line 110.

[0055] In some embodiments, the contact portion may have a stepped portion 110a at the periphery of the contact hole 125. Thus, the contact portion may have a concave portion sunken downward.

[0056] The upper conductive line 130 may be formed on the interlayer insulating layer 120 and may fill the contact hole 125. Therefore, the contact 135 may be formed inside the contact hole 125. The contact 135 may be a portion of the upper conductive line 130 formed inside the contact hole 125 and may be formed as a substantially integral member with the upper conductive line 130.

[0057] The upper conductive line 130 may contact the lower conductive line 110 or the contact portion in the contact hole 125. As described above, the contact portion of the lower conductive line 110 may include a step portion 110a formed by reducing the thickness. Therefore, the contact area of ​​the upper conductive line 130 and the lower conductive line 110 can be increased.

[0058] Therefore, the contact resistance between the upper conductive line 110 and the lower conductive line 130 can be reduced in the contact hole 125, and the adhesion can be increased. Therefore, contact separation and peeling caused by external stress (eg, folding / bending stress) around the contact hole 125 can be suppressed.

[0059] In some embodiments, the thickness of the lower conductive line 110 may be 10 μm or more. For example, the thickness of the lower conductive line 110 may be 10 μm to 25 μm, or 10 μm to 20 μm.

[0060] In some embodiments, the thickness of the upper conductive line 130 may be less than that of the lower conductive line 110. For example, the thickness of the upper conductive line 130 may be about 6 μm or less, and preferably about 1 μm to 6 μm.

[0061] By forming the upper conductive line 130 relatively thin, folding or bending characteristics can be improved while ensuring sufficient channel current or conductive coil current from the lower conductive line 110. In addition, the adhesion characteristics in the contact hole 125 can be further improved by using the upper conductive line 130 in a thin film form.

[0062] The passivation layer 140 may be formed on the interlayer insulating layer 120 to cover the upper conductive line 130. For example, the passivation layer may include an organic or inorganic insulating material substantially the same as or similar to the interlayer insulating layer 120.

[0063] Figure 2 is a partially enlarged cross-sectional view illustrating a lower conductive line in a contact hole according to an exemplary embodiment.

[0064] Reference Figure 2 The contact portion or step portion 110a, which is a portion of the lower conductive line 110 exposed by the contact hole 125, may have an inclined sidewall SW. In some embodiments, the sidewall SW of the contact portion or step portion 110a may have a curved shape, for example, a concave curved shape.

[0065] The contact area and adhesion between the upper conductive line 130 and the lower conductive line 110 can be further increased by the shape of the contact portion. In addition, the peeling and breaking of the conductive lines 110 and 130 in the step portion 110a can be prevented or reduced.

[0066] Figure 3 is a process flow chart illustrating a method of manufacturing an electrode connection structure according to an exemplary embodiment. Figure 4 and Figure 5 is a cross-sectional view showing a method for manufacturing an electrode connection structure according to an exemplary embodiment. Figure 1 and Figure 2 A detailed description of the structure and materials is described.

[0067] Reference Figure 3 and Figure 4 , preparing a metal layer 107 formed on the base material layer 105. In some embodiments, as shown in step S10, the base material layer 105 and the metal layer 107 may be provided in the form of a stacked substrate 60 (eg, a copper clad laminate (FCCL)).

[0068] The surface portion 109 of the metal layer 107 may contain rust-proof materials, oxidized materials, etc. contained in the product state of the laminated substrate 60. For example, in addition to copper (Cu) and the desired metal, the surface portion 109 may also contain rust-proof metals such as zinc (Zn), chromium (Cr), and oxygen components.

[0069] Thereafter, the surface portion 109 of the metal layer 107 may be removed by preliminary soft etching (e.g., step S20). The term "soft etching" used in the present application may refer to a process of etching away a portion of the thickness of a film to be etched (relative to the total thickness). According to an exemplary embodiment, when performing the soft etching, the surface portion 109 of the metal layer 107 may be removed at a predetermined etching rate (e.g., angstroms). The etching time is adjusted under the wet etching process conditions of 0.1% / min) so as to obtain an etching amount corresponding to the desired thickness.

[0070] The lower conductive line 110 may be formed by patterning the metal layer 107 from which the surface portion 109 has been removed. The rust-proof material and the oxidized material contained in the surface portion 109 can be removed or reduced by the preliminary soft etching. Therefore, the resistance and roughness of the surface of the lower conductive line 110 can be reduced.

[0071] Reference Figure 3 and Figure 5 , an interlayer insulating layer 120 covering the lower conductive line 110 may be formed on the substrate layer 105 (e.g., step S30). For example, after forming the interlayer insulating layer 120 completely covering the lower conductive line 110, the interlayer insulating layer 120 may be partially removed by a wet etching process to form a contact hole 125 partially exposing the upper surface of the lower conductive line 110.

[0072] The contact hole 125 may be defined by the sidewall of the interlayer insulating layer 120 and the bottom surface of the lower conductive line 110. In some embodiments, the sidewall of the interlayer insulating layer 120 may be formed to be inclined at a predetermined acute angle less than 90 degrees with respect to the bottom surface of the lower conductive line 110.

[0073] Thereafter, soft etching may be performed on a portion (contact portion) of the lower conductive line 110 exposed by the contact hole 125 (eg, step S40 ). Thus, the thickness of the contact portion can be selectively reduced.

[0074] In some embodiments, as shown in Figure 1 and Figure 2 As described, the stepped portion 110 a and the sidewall SW of the recess may be formed in the contact portion by soft etching.

[0075] The soft etching can remove an oxide film and metal residue formed on the upper surface of the lower conductive line 110 exposed by the contact hole 125. In addition, the soft etching can also remove insulating residues from the interlayer insulating layer 120 generated when the contact hole 125 is formed.

[0076] Therefore, it is possible to improve adhesion and connection reliability while reducing contact resistance of the upper conductive line 110 and the lower conductive line 130 through the contact hole 125 .

[0077] Afterwards, if Figure 1 As shown, an upper conductive line 130 connected to the lower conductive line 110 through the contact hole 125 may be formed. The upper conductive line 130 may be formed by a deposition process such as an electroplating process or a sputtering process. A passivation layer 140 covering the upper conductive line 130 may be formed on the interlayer insulating layer 120.

[0078] Figure 6 and Figure 7 ] are SEM images showing the lower conductive line surface before soft etching and the lower conductive line surface after soft etching, respectively.

[0079] See also Figure 6 and Figure 7 ,After soft etching, the etching residual particles are removed from the surface of the lower conductive wire exposed by the contact hole, thus significantly improving the surface uniformity.

[0080] Figure 8 is a schematic cross-sectional view illustrating a digitizer according to an exemplary embodiment. Fig. 9 and Fig.10 is a schematic plan view showing a conductive coil included in a digitizer according to an exemplary embodiment. For example, Figure 8 is along Fig. 9 The cross-sectional view is taken along the line II' in the thickness direction.

[0081] Reference Figures 8 to 10 , two directions parallel to the upper surface of the digitizer 100 or the substrate layer 105 and intersecting each other are defined as a first direction and a second direction. For example, the first direction and the second direction may intersect each other perpendicularly.

[0082] 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.

[0083] Reference Figures 8 to 10 , the digitizer 100 may include a Figure 1 and Figure 2 According to an exemplary embodiment, the digitizer 100 may include a lower conductive line 110 and an upper conductive line 130 formed on a substrate layer 105. The lower conductive line 110 and the upper conductive line 130 may be divided into different layers with an interlayer insulating layer 120 interposed therebetween.

[0084] The digitizer 100 according to an exemplary embodiment may include a first conductive coil 50 (see Fig. 9 ) and a second conductive coil 70 (see Fig.10 ).

[0085] The lower conductive line 110 and the upper conductive line 130 may be combined through the contact 135 to define the first conductive coil 50 and the second conductive coil 70 .

[0086] The lower conductor 110 may include a first lower conductor 112 (see Fig.10 ) and the second lower conductor 114 (see Fig. 9 ). The upper conductive line 130 may include a first upper conductive line 132 (see Fig. 9 ) and the second upper conductor 134 (see Fig.10 ).

[0087] 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 the first direction.

[0088] like Fig. 9 As shown, the first upper conductive line 132 of the upper conductive lines 130 and the second lower conductive line 114 of the lower conductive lines 110 may be coupled to each other to form a first conductive coil 50 .

[0089] The first upper conductive line 132 and the second lower conductive line 114 together form a first conductive coil 50 , and thus can be provided together as a sensing line for an input pen based on electromagnetic induction.

[0090] For example, the first upper conductive wire 132 and the second lower conductive wire 114 may be electrically connected to each other through the first contact 135a. A plurality of first upper conductive wires 132 and a plurality of second lower conductive wires 114 may be electrically connected to each other through a plurality of first contacts 135a, so that a plurality of conductive rings are included in one first conductive coil 50. For example, four first conductive rings may be included in one first conductive coil 50.

[0091] In some embodiments, the first conductive rings may have different sizes or areas in a planar direction. The first contact 135 a may penetrate the interlayer insulating layer 120 to be substantially integrally formed with the first upper conductive line 132 .

[0092] The first input line 113 and the first output line 115 may be connected to any of the plurality of first conductive rings. For example, the first input line 113 may be connected to the innermost first conductive ring, and the first output line 115 may be connected to the outermost first conductive ring.

[0093] The current input from the first input line 113 may circulate alternately through the lower conductive line 110 and the upper conductive line 130 through the first conductive ring, and may flow out through the first output line 115 .

[0094] In some embodiments, the first input line 113 and the first output line 115 may be included in the lower conductive line 110 .

[0095] In some embodiments, the lower conductive line 110 may include a first internal connecting line 114 a. For example, adjacent first conductive rings may be connected by the first internal connecting line 114 a.

[0096] like Fig.10 As shown, the first lower conductive line 112 of the lower conductive lines 110 and the second upper conductive line 134 of the upper conductive lines 130 may be coupled to each other to form a second conductive coil 70 .

[0097] The first lower conductive line 112 and the second upper conductive line 134 together form a second conductive coil 70 , and thus can be used together as a sensing line for an input pen based on electromagnetic induction.

[0098] 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 135b. 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 a plurality of second contacts 135b, so that a plurality of conductive rings are included in one second conductive coil 70. For example, four second conductive rings may be included in one second conductive coil 70.

[0099] In some embodiments, the second conductive rings may have different sizes or areas in a planar direction. The second contact 135 b may penetrate the interlayer insulating layer 120 to be substantially integrally formed with the second upper conductive line 134 .

[0100] A second input line 117 and a second output line 119 may be connected to any second conductive ring among the plurality of second conductive rings. For example, the second input line 117 may be connected to the innermost second conductive ring, and the second output line 119 may be connected to the outermost second conductive ring.

[0101] The current input from the second input line 117 may circulate alternately through the lower conductive line 110 and the upper conductive line 130 through the second conductive ring, and may flow out through the second output line 119 .

[0102] In some embodiments, the second input line 117 and the second output line 119 may be included in the lower conductive line 110 .

[0103] In some embodiments, the upper conductive line 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 to the second conductive ring through the second contact 135b via the external connection line 134a.

[0104] In one embodiment, the external connection line 134a may also be connected to two different second conductive coils. For example, the output line 119 connected to one second conductive coil 70 may be connected to the input line 117 of another second conductive coil 70 via the external connection line 134a.

[0105] In some embodiments, the upper conductive line 130 may further include a second internal connecting line 134b. For example, adjacent second conductive rings within the second conductive coil 70 may be connected to each other through the second internal connecting line 134b.

[0106] Fig. 9 and Fig.10It is shown that four conductive rings are included in one conductive coil, but the number of conductive rings in the conductive coil may be adjusted in consideration of the size and resolution of the image display device.

[0107] As reference Fig. 9 and Fig.10 As described, the first conductive coil 50 and the second conductive coil 70 may each include a plurality of conductive loops of different sizes.

[0108] Therefore, by sufficiently increasing the strength of the magnetic field generated by the digitizer 100, energy transmission to, for example, an input pen contacting a window surface of an image display device can be effectively enhanced.

[0109] In addition, since the lower conductive line 110 and the upper conductive line 130 are connected through the contact 135 to form a conductive loop, the number of loops of the conductive coil within a limited space can be effectively increased, and the electromagnetic induction efficiency can be improved.

[0110] As described above, the thickness of the lower conductive line 110 may be greater than the thickness of the upper conductive line 130. Fig.11 In the embodiment of the present invention, the upper conductive line 130 may extend in a first direction (e.g., a row direction or a width direction) and intersect the folding axis. For example, the upper conductive line 130 may be perpendicular to the folding axis. The lower conductive line 110 may extend in a second direction (a column direction or a length direction) and be substantially parallel to the folding axis.

[0111] According to an exemplary embodiment, cracks in the wire can be reduced or suppressed (prevented) by reducing the thickness of the upper wire 130 (since the upper wire 130 intersects the folding axis, the folding / bending stress is easily transmitted to the upper wire 130). The current path through the conductive coil can be expanded by forming the lower wire 110 with a larger thickness (since the lower wire 110 is parallel to the folding axis and is relatively free from the folding / bending stress), thereby achieving a sufficient electromagnetic induction effect.

[0112] In addition, as referenced Figure 1 As described, the contact 135 may contact the contact portion of the lower conductive line 110 having a reduced thickness and including the step portion 110a. As described above, the surface of the contact portion may have surface characteristics improved by soft etching.

[0113] Therefore, the contact resistance in the contact hole 125 can be reduced and the warping / peeling of the contact 135 can be suppressed, so that a highly reliable conductive coil structure can be realized.

[0114] Fig.11 is a schematic plan view showing a digitizer according to an exemplary embodiment. For ease of explanation, Fig.11 The detailed structure / configuration of the conductive coil is omitted.

[0115] Reference Fig.11 , a plurality of first conductive coils 50 and second conductive coils 70 may be arranged on the upper surface of the substrate layer 105 .

[0116] The first conductive coil 50 may extend in a first direction or a row direction, and a plurality of first conductive coils 50 may be arranged in a second direction or a column direction.

[0117] For example, n first conductive coils 50-1 to 50-n (n is a natural number) may be sequentially arranged along the second direction. In some embodiments, adjacent first conductive coils 50-1 to 50-n may be sequentially arranged along the second direction to partially overlap each other in the planar direction.

[0118] The second conductive coil 70 may extend along the second direction or the column direction. A plurality of second conductive coils 70 may be arranged along the first direction or the row direction.

[0119] For example, m second conductive coils 70 - 1 to 70 - m may be sequentially arranged along the first direction. In some embodiments, adjacent second conductive coils 70 - 1 to 70 - m may be sequentially arranged along the first direction to partially overlap each other in the planar direction.

[0120] For example, the active area AA where the first conductive coil and the second conductive coil are overlapped may be used as a substantial digitizer sensing area.

[0121] 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 located within the folding area FA. The digitizer 100 according to the exemplary embodiment may be bent or folded around the folding axis 80 .

[0122] As described above, in some embodiments, the thickness of the upper conductive line 130 intersecting the folding axis 80 may be relatively small. Therefore, it is possible to prevent the upper conductive line 130 to which bending stress is directly applied from being broken and increase flexibility.

[0123] The resistance can be reduced and the efficiency of magnetic field generation through the conductive coil can be improved by increasing the thickness of the lower conductive line 110 which is parallel to the folding axis 80 and is subject to relatively less folding / bending stress.

[0124] In addition, by using the reference Figure 1 The electrode connection structure described can maintain a stable electrical connection between the conductive coils 50 and 70 to generate the desired electromagnetic field even if the thickness of the upper conductive wire 130 is reduced when the conductive coils 50 and 70 are repeatedly folded or bent.

[0125] Refer again Figure 8, the interlayer insulating layer 120 may have a reduced thickness in the folding area FA. In one embodiment, the interlayer insulating layer 120 may be removed in the folding area FA. Thus, the folding characteristics and flexibility of the folding area FA can be further improved.

[0126] In some embodiments, the passivation layer 140 may also have a reduced thickness in the folding area FA.

[0127] Fig.12 is a schematic cross-sectional view illustrating an image display device according to an exemplary embodiment.

[0128] Reference Fig.12 , the image display device may include a display panel 360 , a touch sensor 200 , and the digitizer 100 according to the above exemplary embodiments.

[0129] 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 back cover 380.

[0130] The digitizer 100 may include a relatively thick and may include a plurality of conductive coils to achieve magnetic field generation efficiency using an electromagnetic induction phenomenon. Therefore, the digitizer 100 may be disposed below the display panel 360 so that it is not visible to a user of the image display device.

[0131] As described above, by using the structure of the digitizer 100 according to the exemplary embodiment, it is possible to sufficiently increase the magnetic field strength, thereby effectively improving energy transfer to, for example, an input pen contacting the window substrate 230 of the image display device.

[0132] According to an exemplary embodiment, the digitizer 100 may be disposed on the back side of the image display device or below the display panel 360. Therefore, the wires included in the digitizer 100 can be invisible to the user. Therefore, each wire included in the digitizer 100 may be formed as a solid wire including the above-mentioned metal without adopting a mesh structure to improve transmittance.

[0133] Therefore, it is possible to ensure a sufficient current path through the conductive wire to improve electromagnetic induction efficiency.

[0134] The display panel 360 may include a pixel electrode 310 , a pixel defining film 320 , a display layer 330 , an opposing electrode 340 , and an encapsulation layer 350 disposed on a panel substrate 300 .

[0135] A pixel circuit including a thin film transistor (TFT) may be formed on the panel substrate 300, and an insulating film covering the pixel circuit may be formed. The pixel electrode 310 may be electrically connected to, for example, a drain electrode of the TFT on the insulating film.

[0136] The pixel defining layer 320 may be formed on the insulating layer to expose the pixel electrode 310 to define a pixel region. The display layer 330 may be 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.

[0137] The counter electrode 340 may be disposed on the pixel defining layer 320 and the display layer 330 . For example, the counter electrode 340 may be provided as a common electrode or a cathode of the image display device. An encapsulation layer 350 for protecting the display panel 360 may be stacked on the counter electrode 340 .

[0138] The touch sensor 200 may be stacked on the display panel 360 and arranged to face the window substrate 230. The touch sensor 200 may generate capacitance by a touch input by a user through the surface of the window substrate 230. Therefore, the touch sensor 200 may include a sensing electrode or a sensing channel having a thickness less than that of a conductive layer included in the digitizer 100, so that they are not visible to 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.

[0139] The sensing electrodes or sensing channels may be independently arranged within a single layer and interact with adjacent sensing electrodes or sensing channels to generate capacitance.

[0140] The touch sensor 200 may be coupled to the display panel 360 through the adhesive layer 260 .

[0141] The window substrate 230 may include, for example, a hard coating film and thin glass, and in one embodiment, a light shielding pattern 235 may be formed on the periphery of one surface of the window substrate 230. The light shielding pattern 235 may include, for example, a color printed pattern. A frame portion or a non-display area of ​​the image display device may be defined by the light shielding pattern 235.

[0142] A polarizing 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.

[0143] The polarizing layer 210 may be directly bonded to one surface of the window substrate 230, or may be attached through the first point bonding layer 220. The touch sensor 200 may be coupled to the polarizing layer 210 through the second point bonding layer 225.

[0144] like Fig.12 As shown, the window substrate 230, the polarizing layer 210 and the touch sensor 200 can be arranged in sequence from the user's viewing side. In this case, since the sensing electrode of the touch sensor 200 is arranged below the polarizing layer 210, the visibility of the sensing electrode can be more effectively prevented.

[0145] In one embodiment, the touch sensor 200 may be directly transferred to 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 sequence from the viewing side of the user.

Claims

1. An electrode connection structure, comprising: substrate layer; A lower conductor arranged on the upper surface of the substrate layer; an interlayer insulating layer formed on an upper surface of the base material layer to partially cover the lower conductive line and including a contact hole exposing an upper surface of the lower conductive line; as well as an upper conductive line disposed on the interlayer insulating layer and electrically connected to the lower conductive line through the contact hole, The lower conductive line has a reduced thickness within the contact hole. 2 . The electrode connection structure according to claim 1 , wherein the lower conductive line includes a stepped portion within the contact hole. The electrode connection structure according to claim 2 , wherein the step portion comprises a curved surface. The electrode connection structure according to claim 2 , wherein the step portion has a concave side wall. 5 . The electrode connection structure according to claim 2 , wherein the interlayer insulating layer has a side wall inclined at an acute angle with respect to an upper surface of the lower conductive line. The electrode connection structure according to claim 1 , wherein a thickness of the lower conductive line is greater than a thickness of the upper conductive line. 7 . The electrode connection structure according to claim 1 , wherein the lower conductive line and the upper conductive line extend in directions crossing each other.

8. A digitizer, comprising the electrode connection structure according to claim 1, The lower conductive line includes a plurality of lower conductive lines, the upper conductive line includes a plurality of upper conductive lines, and the plurality of lower conductive lines and the plurality of upper conductive lines are combined with each other through the contact holes to form a plurality of conductive coils. 9 . The digitizer of claim 8 , wherein the plurality of lower conductive lines include first and second lower conductive lines extending in a column direction, and the plurality of upper conductive lines include first and second upper conductive lines extending in a row direction.

10. The digitizer of claim 9, wherein the plurality of conductive coils comprises: a first conductive coil formed by connecting the first upper conductive wire and the second lower conductive wire to each other; and a second conductive coil formed by connecting the first lower conductive wire and the second upper conductive wire to each other.

11. The digitizer according to claim 10, wherein the first conductive coil extends in a row direction, and a plurality of the first conductive coils are arranged in a column direction; and the second conductive coil extends in a column direction, and a plurality of the second conductive coils are arranged in a row direction. 12 . The digitizer of claim 8 , wherein the substrate layer comprises a folding region, a folding axis of the folding region intersecting the upper conductive line and being parallel to the lower conductive line.

13. A method for manufacturing an electrode connection structure, comprising: forming a lower conductive line on the substrate layer; forming an interlayer insulating layer including a contact hole on the substrate layer, wherein the contact hole partially exposes the upper surface of the lower conductive line; reducing the thickness of a portion of the lower conductive line exposed by the contact hole by soft etching; as well as An upper conductive line filling the contact hole is formed on the interlayer insulating layer.

14. The method for manufacturing an electrode connection structure according to claim 13, wherein forming the lower conductive line on the substrate layer comprises: preparing a laminate substrate including a base material layer and a metal layer; as well as The surface portion of the metal layer is removed by preliminary soft etching. 15 . The method for manufacturing an electrode connection structure according to claim 14 , wherein the preliminary soft etching comprises removing a rust-proof material or an oxidized material included on a surface of the metal layer. 16 . The method for manufacturing an electrode connection structure according to claim 13 , wherein the soft etching comprises removing metal residues or insulating residues on a surface of the lower conductive line exposed by the contact hole.

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