1. A touch sensor stack-up structure, comprising:

a touch sensor structure including an engagement portion;

a circuit connection structure bonded to the bonding portion of the touch sensor structure; and

an optical film stacked on the touch sensor structure, wherein the optical film includes a protrusion covering an end portion of the circuit connection structure and overlapping the bonding portion.

2. The touch sensor stack structure of claim 1, wherein the protrusion of the optical film comprises a wing portion protruding from a lateral side of the bonding portion in a plan view.

3. The touch sensor stack-up structure of claim 1, wherein the width of the wing portion is 0.1 μ ι η to about 50 μ ι η.

4. The touch sensor stack-up structure of claim 1, wherein the touch sensor structure comprises:

a substrate layer;

a sense electrode disposed on the substrate layer; and

a pad portion gathered in the bonding portion and electrically connected to the sensing electrode.

5. The touch sensor stack structure of claim 4, wherein the circuit connection structure is electrically connected to the pad portion and comprises a flexible printed circuit board.

6. The touch sensor stack-up structure of claim 1, wherein the optical film comprises a polarizer.

7. The touch sensor stack-up structure of claim 1, wherein the engaging portion protrudes from a side of the touch sensor structure, and the protrusion extends from a side of the optical film,

wherein a width of the protrusion of the optical film is greater than a width of the bonding portion of the touch sensor structure.

8. A method of fabricating a touch sensor stack structure, comprising:

preparing a touch sensor structure;

partially removing an end portion of the touch sensor structure by a first cutting process to form a joint;

engaging a circuit connecting structure on the engaging portion;

forming an optical film on the touch sensor structure to cover an end portion of the circuit connection structure; and

cutting the touch sensor structure and a portion of the optical film around the bonding portion by a second cutting process.

9. The method of claim 8, wherein the first cutting process comprises forming an alignment key at a corner portion of the touch sensor structure.

10. The method of claim 9, wherein the second cutting process comprises aligning a cutting tool with reference to the alignment key.

11. The method of claim 9, wherein the second cutting process comprises cutting the corner portion formed with the alignment key.

12. The method of claim 8, wherein the end portion of the touch sensor structure includes a joint region and edge regions adjacent to both sides of the joint region, and

the first cutting process includes cutting the edge region.

13. A window stack structure, comprising:

the touch sensor stack-up structure of claim 1; and

a window substrate disposed on the touch sensor stack structure.

14. The window stack-up structure of claim 13, wherein the optical film of the touch sensor stack-up structure comprises a polarizer, and

the optical film is disposed between the window substrate and the touch sensor structure.

15. An image display device, comprising:

a display panel; and

the touch sensor stack-up structure of claim 1, stacked on the display panel.

Background

With the development of information technology, various demands for display devices having thinner sizes, light weights, high power consumption efficiency, and the like are increasing. The display device may include a flat panel display device such as a Liquid Crystal Display (LCD) device, a Plasma Display Panel (PDP) device, an electroluminescence display device, an Organic Light Emitting Diode (OLED) display device, and the like.

A touch panel or a touch sensor capable of inputting a user's direction by selecting an instruction displayed on a screen with a finger or an input tool has also been developed. The touch panel or the touch sensor may be combined with a display device so that display and information input functions can be implemented in one electronic device.

For example, the touch panel may include a sensing electrode and a pad applying a signal to the sensing electrode. The pads may be electrically connected to a circuit member to which a driving signal may be applied. In addition, an optical film (such as a polarizing plate) of the display device may be laminated on the touch panel.

Accordingly, the touch panel, the circuit member, and the optical film may be manufactured as one module or laminate, and may require precise interlayer alignment, a cutting process, and the like. In addition, the electrodes included in the touch panel may be damaged due to the lamination process or bending of the laminate.

For example, as disclosed in korean registered patent publication No. 10-2078385, various image display devices combined with a touch screen panel have been recently developed. However, a processing configuration in the aspect of optical film lamination, circuit member bonding, and the like is not suggested.

Disclosure of Invention

According to an aspect of the present invention, a touch sensor stack structure having improved mechanical stability and reliability is provided.

According to an aspect of the present invention, a method of manufacturing a touch sensor stack structure having improved mechanical stability and reliability is provided.

The above aspects of the inventive concept are achieved by the following features or configurations:

(1) a touch sensor stack structure comprising: a touch sensor structure including an engagement portion; a circuit connection structure bonded to the bonding portion of the touch sensor structure; and an optical film stacked on the touch sensor structure, wherein the optical film includes a protrusion covering an end portion of the circuit connection structure and overlapping the bonding portion.

(2) The touch sensor stack structure according to the above (1), wherein the protruding portion of the optical film includes a wing portion protruding from a lateral side of the joining portion in a plan view.

(3) The touch sensor stack-up structure of (1) above, wherein the width of the wing portion is 0.1 μm to about 50 μm.

(4) The touch sensor stack-up structure of (1) above, wherein the touch sensor structure comprises: a substrate layer; a sense electrode disposed on the substrate layer; and a pad portion gathered in the bonding portion and electrically connected to the sensing electrode.

(5) The touch sensor stack-up structure according to the above (4), wherein the circuit connection structure is electrically connected to the pad portion, and includes a flexible printed circuit board.

(6) The touch sensor stack-up structure of (1) above, wherein the optical film comprises a polarizing plate.

(7) The touch sensor stack-up structure of (1) above, wherein the joining portion protrudes from one side of the touch sensor structure, and the protrusion extends from one side of the optical film, wherein a width of the protrusion of the optical film is greater than a width of the joining portion of the touch sensor structure.

(8) A method of manufacturing a touch sensor stack structure, comprising: preparing a touch sensor structure; partially removing an end portion of the touch sensor structure by a first cutting process to form a joint; engaging a circuit connecting structure on the engaging portion; forming an optical film on the touch sensor structure to cover an end portion of the circuit connection structure; and cutting the touch sensor structure and a portion of the optical film around the bonding portion through a second cutting process.

(9) The method of (8) above, wherein the first cutting process comprises forming an alignment key at a corner portion of the touch sensor structure.

(10) The method of (9) above, wherein the second cutting process comprises aligning a cutting tool with reference to the alignment key.

(11) The method according to the above (9), wherein the second cutting process includes cutting the corner portion formed with the alignment key.

(12) The method of (8) above, wherein the end portion of the touch sensor structure includes a joint region and edge regions adjacent to both sides of the joint region, and the first cutting process includes cutting the edge regions.

(13) A window stack structure comprising: the touch sensor stack structure according to the embodiment as described above; and a window substrate disposed on the touch sensor stack structure.

(14) The window stack-up structure according to the above (13), wherein the optical film of the touch sensor stack-up structure includes a polarizing plate, and the optical film is disposed between the window substrate and the touch sensor structure.

(15) An image display apparatus comprising: a display panel; and the touch sensor stack structure according to the embodiment as described above, which is stacked on the display panel.

According to the embodiment of the present invention, a first cutting process for cutting a peripheral portion around a bonding area of the touch sensor structure may be performed, and then the circuit connection structure may be bonded. Later, an optical film such as a polarizing plate may be laminated, and the peripheral portions of the touch sensor structure and the optical film around the bonding region may be cut by a second cutting process. Electrode cracks occurring at the edge portion of the touch sensor layer may be prevented and cutting stress may be distributed by a sequentially repeated cutting process.

In some implementations, the alignment keys can be formed together on the touch sensor layer while the first cutting process is performed. An alignment key may be used to improve the accuracy and reliability of the second cutting process.

In some embodiments, the cut portion of the optical film obtained by the second cutting process may include a step portion or a wing portion protruding from the cut portion of the touch sensor layer. The wing portion may serve as an electrode protection pattern of the touch sensor layer, so that electrode cracks and electrode corrosion at the edge portion of the touch sensor structure may be prevented. Furthermore, bending stresses in the joining region can be reduced by the wing portions.

Drawings

Fig. 1 to 5 are schematic top plan views illustrating a method of manufacturing a touch sensor stack structure according to an exemplary embodiment.

Fig. 6 is a partially enlarged top plan view illustrating a cut portion around a bonding portion of a touch sensor stack structure according to an exemplary embodiment.

Fig. 7 is a schematic sectional view illustrating a window stack structure and an image display device according to an exemplary embodiment.

Detailed Description

According to an exemplary embodiment of the present invention, there is provided a touch sensor stack structure including an optical film and a circuit connection structure. There is also provided, in accordance with an exemplary embodiment of the present invention, a method of manufacturing a touch sensor structure, the method including a lamination process and a cutting process of an optical film.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. However, those skilled in the art will appreciate that such embodiments described with reference to the accompanying drawings are provided for further understanding of the spirit of the invention and do not limit the claimed subject matter as disclosed in the detailed description and the appended claims.

Fig. 1 to 5 are schematic top plan views illustrating a method of manufacturing a touch sensor stack structure according to an exemplary embodiment.

Referring to fig. 1, a touch sensor structure 100 may be prepared. The touch sensor structure 100 can include sense electrodes 110 and 120 disposed on a substrate layer 105.

The substrate layer 105 may comprise a flexible and transparent insulating material. For example, the substrate layer 105 may include a resin material such as Cyclic Olefin Polymer (COP), polyethylene terephthalate (PET), Polyacrylate (PAR), Polyetherimide (PEI), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polyallyl ester, Polyimide (PI), Cellulose Acetate Propionate (CAP), Polyethersulfone (PES), cellulose Triacetate (TAC), Polycarbonate (PC), Cyclic Olefin Copolymer (COC), polymethyl methacrylate (PMMA), or the like. The substrate layer 105 may include an inorganic insulating material such as glass, silicon oxide, or the like.

The substrate layer 105 may include an active area AA, a bonding area BA, and an edge area MA. The active area AA may include a central portion of the substrate layer 105 and may be an area that may substantially recognize a user touch and may generate a signal.

For example, when a touch of a user is input onto the active area AA, a change in capacitance may occur due to the sensing electrodes 110 and 120. Thus, a physical touch can be converted into an electrical signal to implement touch sensing.

The sensing electrodes 110 and 120 may include a first sensing electrode 110 and a second sensing electrode 120.

The first sensing electrodes 110 may be arranged along a length direction or a column direction of the substrate layer 105 or the touch sensor stack structure, for example. Accordingly, the first sensing electrode row may be formed of a plurality of first sensing electrodes 110. Additionally, the plurality of first sensing electrode columns may be arranged in a width direction or a row direction.

In some embodiments, the first sensing electrodes 110 adjacent in the column direction may be physically or electrically connected to each other through the connection part 115. For example, the connection part 115 may be integrally formed with the first sensing electrode 110 on the same level.

The second sensing electrodes 120 may be arranged in a row direction or a width direction. In some embodiments, the second sensing electrodes 120 may be physically spaced apart from each other as island-type unit electrodes. In this case, the second sensing electrodes 120 adjacent in the row direction may be electrically connected to each other through the bridge electrode 125.

The plurality of second sensing electrodes 120 may be connected to each other in the first direction by the bridge electrode 125, so that a second sensing electrode row may be formed. The plurality of second sensing electrode rows may be arranged along a column direction or a length direction.

Sensing electrodes 110 and 120 and/or bridging electrode 125 may each 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), molybdenum (Mo), calcium (Ca), or an alloy containing at least one of the metals (e.g., silver palladium copper (APC), copper calcium (CuCa)). These may be used alone or in combination. For example, the sensing electrodes 110 and 120 may have a mesh structure including a metal or an alloy.

The sensing electrodes 110 and 120 and the bridging electrode 125 may each include a transparent conductive material. For example, the sensing electrodes 110 and 120 and the bridging electrode 125 may include transparent conductive oxides such as Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), zinc oxide (ZnO), Indium Zinc Tin Oxide (IZTO), and Cadmium Tin Oxide (CTO), silver nanowires (AgNW), Carbon Nanotubes (CNTs), graphene, conductive polymers, and the like.

In some embodiments, the sensing electrodes 110 and 120 may include a stacked structure of a transparent conductive oxide layer and a metal layer. For example, the sensing electrodes 110 and 120 may include a double-layer structure of a transparent conductive oxide layer-metal layer or a triple-layer structure of a transparent conductive oxide layer-metal layer-transparent conductive oxide layer. In this case, the flexibility characteristics can be improved by the metal layer, and the signal transmission speed can also be improved by the low resistance of the metal layer. The transparent conductive oxide layer may improve corrosion resistance and transparency.

In some embodiments, the bridge electrode 125 may be formed on an insulating layer (not shown). The insulating layer may at least partially cover the connection portion 115 included in the first sensing electrode 110, and may at least partially cover the second sensing electrode 120 surrounding the connection portion 115. The bridge electrode 125 may be formed through the insulating layer and may be electrically connected to the second sensing electrodes 120 adjacent to each other with the connection portion 115 interposed therebetween.

The insulating layer may include an inorganic insulating material such as silicon oxide or silicon nitride, or an organic insulating material such as acrylic resin or siloxane resin.

The traces 130 may be bifurcated and extend from each of the first and second columns and rows of sense electrodes. The trace 130 may be bifurcated from an end portion of each of the first and second sensing electrode columns and the second sensing electrode row, and may extend over a peripheral area surrounding the active area AA.

The trace 130 may extend in a length direction toward a bonding area BA assigned to a portion of one end of the touch sensor structure 100. The terminal ends of the traces 130 may be grouped on a bonding area BA of the substrate layer 105. The pad parts 140 may be formed on the bonding areas BA and may be individually connected to the traces 130. In an embodiment, the terminal ends of the traces 130 may be provided as pad portions 140.

For convenience of description, an illustration of a connection structure between the trace 130 and the pad part 140 is omitted in fig. 1.

In some implementations, the touch sensor structure 100 can be formed by a transfer process. For example, a sensing electrode layer including the sensing electrodes 110 and 120, the bridge electrode 125, and the trace 130 described above may be formed on a carrier substrate. Later, the sensing electrode layer may be transferred to the substrate layer 105, and the carrier substrate may be peeled off and removed to obtain the touch sensor structure 100.

In an embodiment, a separation layer including an organic material for facilitating a lift-off process may be formed between the sensing electrode layer and the carrier substrate. The sensing electrode layer and the substrate layer 105 may be bonded to each other through an adhesive layer.

As shown in fig. 1, the edge area MA may be included at one end of the substrate layer 105 or touch sensor structure 100 in the length direction. For example, areas adjacent to both sides of the bonding area BA may be allocated as the edge area MA.

Hereinafter, for convenience of description, illustration of detailed electrode arrangements included in the touch sensor structure 100 is omitted.

Referring to fig. 2, a first cutting process may be performed on the touch sensor structure 100.

In an exemplary embodiment, the edge area MA of the touch sensor structure 100 shown in fig. 1 may be at least partially removed by a first cutting process. The bonding area BA may be at least partially preserved by the first cutting process so that the bonding part 150 may be formed.

The bonding portion 150 may include the pad portion 140 and may serve as a bonding label for a bonding process with a circuit connection structure, as will be described below. For example, as shown in fig. 2, the engaging portion 150 may have a generally trapezoidal shape in plan view.

As described above, the edge area MA may be at least partially removed by the first cutting process so that the recess 160 may be formed at one end of the touch sensor structure 100 or the substrate layer 105. For example, two recesses 160 may be formed with the engaging portion 150 interposed therebetween.

In an exemplary embodiment, the alignment key 170 may be formed along with the recess 160 during the first cutting process. In some implementations, the alignment key 170 can be formed at a corner portion of one end of the touch sensor structure 100 or the substrate layer 105.

For example, the align key 170 may be formed at both corner portions of the upper portion of the touch sensor structure 100 in fig. 2. The alignment key 170 may have a hole shape.

Referring to fig. 3, the circuit connection structure 180 may be joined to the joining portion 150.

In an exemplary embodiment, the circuit connection structure 180 may include a Flexible Printed Circuit Board (FPCB). For example, the circuit connection structure 180 may include a core layer and circuit wirings formed on the core layer.

For example, the circuit connection structure 180 may be aligned on the bonding part 150, and then a hot pressing process may be performed using a pressing tool such as a soldering tip, so that the circuit wiring of the circuit connection structure 180 and the pad part 140 included in the bonding part 150 may be electrically connected to each other.

In some embodiments, the conductive intermediate film 185 may be disposed between the collective portion 150 and the circuit connection structure 180, and then the bonding process may be performed by compressing the bonding portion 150 and the circuit connection structure 180 toward each other. For example, the conductive intermediate film 185 may include an Anisotropic Conductive Film (ACF).

According to the above-described exemplary embodiments, the bonding process may be performed in a state where the recess 160 is formed in the touch sensor structure 100 through the first cutting process. Accordingly, damage to the traces 130 included in the touch sensor structure 100 that may be caused when stress generated by heat/pressure from the bonding process is transferred to the substrate layer 105 may be prevented.

Referring to fig. 4, an optical film 200 may be laminated on the touch sensor structure 100.

In an exemplary embodiment, the optical film 200 may include a film or a layer structure known in the art for improving image visibility of an image display device. Non-limiting examples of the optical film 200 may include a polarizing plate, a polarizer, a retardation film, a reflective sheet, a brightness enhancement film, an index matching film. These may be used alone or in a multilayer structure including two or more thereof.

In an embodiment, the optical film 200 may be a polarizing plate. In this case, the optical film 200 may include, for example, a polyvinyl alcohol-based polarizer and a protective film formed on at least one surface of the polarizer. The protective film may include, for example, a resin material such as triacetyl cellulose (TAC) and cycloolefin polymer (COP).

In some embodiments, the optical film 200 may partially cover the bonding portion 150 and partially cover the end portion of the circuit connection structure 180. The optical film 200 may partially cover the end portion of the recess 160.

Referring to fig. 5, the optical film 200 and the touch sensor structure 100 may be cut together by a second cutting process.

In an exemplary embodiment, end portions of the touch sensor structure 100 and the optical film 200 adjacent to the circuit connection structure 180 and the bonding portion 150 may be cut and removed by a second cutting process. Thus, the touch sensor structure 100 and the optical film 200 can share substantially the same cutting plane around the engagement portion 150.

In some embodiments, the second cutting process may be performed using the alignment key 170 formed in the first cutting process. For example, the cutting tool for the second cutting process may be aligned with reference to the alignment key 170. The alignment key 170 may be removed along with the corner portions of the touch sensor structure 100 through a second cutting process.

In some embodiments, two lateral portions of the touch sensor structure 100 and the optical film 200 around the bonding portion 150 may be cut by a second cutting process. Accordingly, the recess 160 included in the touch sensor structure 100 may also be removed by the second cutting process.

In an exemplary embodiment, the protrusion 210 may be formed at the end portion of the optical film 200 through a second cutting process. The protrusion 210 may partially overlap the coupling portion 150 and may cover an end portion of the circuit connection structure 180.

The protrusion 210 may be formed of the optical film 200 so that the circuit connection structure 180 may be more stably fixed on the bonding part 150. For example, the circuit connection structure 180 may be bent downward to be connected to a main board of the image display device. In this case, the circuit connection structure 180 may be bent together with the junction portion 150.

The joint portion 150 having a reduced width may be formed by the touch sensor structure 100 through the first and second cutting processes as described above, so that bending may be more easily performed. Further, when bending is performed using the protrusion 210 of the optical film 200, the circuit connection structure 180 may be prevented from being separated, and cracks and delamination of the pad part 140 may also be prevented.

Additionally, the pad part 140 may be covered by the protrusion 210 of the optical film 200, so that corrosion of the pad part 140 may be substantially suppressed or reduced.

Fig. 6 is a partially enlarged top plan view illustrating a cut portion around a bonding portion of a touch sensor stack structure according to an exemplary embodiment.

Referring to fig. 6, as described above, the optical film 200 may include the protrusion 210 partially covering the bonding portion 150 and the circuit connection structure 180. In an exemplary embodiment, the width of the protrusion 210 may be greater than the width of the engagement portion 150 of the touch sensor structure 100.

Accordingly, the protrusion 210 may include a wing portion 220 protruding from a lateral surface of the engagement portion 150 in the width direction. The wing portion 220 may act as a cover layer that protects the lateral surfaces of the joint portion 150 included in the touch sensor structure 100. Therefore, corrosion of the pad portion 140 caused by moisture and air penetrating the lateral surfaces of the bonding portion 150 may be additionally prevented.

In an embodiment, the width D of the wing portion 220 may be from about 0.1 μm to about 50 μm. When the width of the wing portion 220 exceeds about 50 μm, the step difference between the touch sensor structure 100 and the optical film 200 may be excessively increased to cause mechanical defects.

Fig. 7 is a schematic sectional view illustrating a window stack structure and an image display device according to an exemplary embodiment.

Referring to fig. 7, the window stack structure 300 may include the window substrate 350 and the touch sensor stack structure 320 according to the exemplary embodiment as described above.

The window substrate 350 may include, for example, a hard coated film, a thin glass (e.g., ultra-thin glass (UTG)). In an embodiment, the light blocking pattern 340 may be formed on a peripheral portion of the surface of the window substrate 340. The light blocking pattern 340 may include a color printed pattern, and may have a single layer or a multi-layer structure.

A bezel portion or a non-display area of the image display apparatus may be defined by the light blocking pattern 340. The light blocking pattern 340 may serve as a decorative film or a decorative pattern.

The touch sensor stack structure 320 may be combined with the window substrate 350 as a film or a panel. In an embodiment, the touch sensor stack structure 320 may be combined with the window substrate 350 via the first adhesive layer 330.

For example, the window substrate 350, the optical film 200 of the touch sensor stack structure 320, and the touch sensor structure 100 of the touch sensor stack structure 320 may be sequentially disposed from the perspective of a viewer. In this case, the sensing electrode of the touch sensor structure 200 may be disposed under an optical film including a polarizing layer or a polarizing plate, so that it is possible to effectively prevent a viewer from recognizing the electrode pattern.

The image display device may include a display panel 400 and a window stack structure 300 including a touch sensor stack structure 320 according to an exemplary embodiment.

The display panel 400 may include a pixel electrode 410, a pixel defining layer 420, a display layer 430, an opposite electrode 440, and an encapsulation layer 450 disposed on a panel substrate 405.

The panel substrate 405 may include a flexible resin material. In this case, the image display device may be provided as a flexible display.

A pixel circuit including a Thin Film Transistor (TFT) may be formed on the panel substrate 405, and an insulating layer covering the pixel circuit may be formed. The pixel electrode 410 may be electrically connected to, for example, a drain electrode of a TFT on an insulating layer.

The pixel defining layer 420 may be formed on the insulating layer, and the pixel electrode 410 may be exposed through the pixel defining layer 420, so that a pixel region may be defined. The display layer 430 may be formed on the pixel electrode 410, and the display layer 430 may include, for example, a liquid crystal layer or an organic light emitting layer.

The opposite electrode 440 may be disposed on the pixel defining layer 420 and the display layer 430. The opposite electrode 440 may serve as, for example, a common electrode or a cathode of the image display device. An encapsulation layer 450 may be disposed on the opposite electrode 440 to protect the display panel 400.

In some embodiments, the display panel 400 and the touch sensor stack structure 320 may be combined with each other by the second adhesive layer 310. For example, the thickness of the second adhesive layer 310 may be greater than the thickness of the first adhesive layer 330. The viscoelasticity of the second adhesive layer 310 may be about 0.2MPa or less at a temperature in the range of-20 ℃ to 80 ℃. In this case, noise from the display panel 400 may be blocked, and interface stress when bent may be relieved, so that damage of the window stack structure 300 may be avoided. In embodiments, the viscoelastic properties of the second adhesive layer 310 may be in the range of about 0.01Mpa to about 0.15 Mpa.