KR102517375B1 - Flexible touch sensor and method of manufacturing the same - Google Patents

Abstract

The present invention is a base layer; a first sensing pattern formed on the substrate layer with unit patterns spaced apart in a first direction and a second sensing pattern formed in a second direction and connected through a joint portion; a bridge electrode connecting spaced apart unit patterns of the first sensing pattern; an insulating layer interposed between the first and second sensing patterns and the bridge electrode and having a contact hole; The insulating layer includes a first region formed on the first and second detection patterns and a second region having a thickness smaller than that of the first region and formed above the gap of the unit pattern. According to the present invention, there is an effect of improving flexible characteristics while satisfying durability.

Description

Flexible touch sensor and its manufacturing method {FLEXIBLE TOUCH SENSOR AND METHOD OF MANUFACTURING THE SAME}

The present invention relates to a flexible touch sensor and a manufacturing method thereof. More specifically, the present invention relates to a flexible touch sensor capable of maintaining durability and improving flexible characteristics and a manufacturing method thereof.

Recently, a flexible display device having a flexible substrate made of a material such as plastic as well as light in weight and strong against impact has been developed. Such a flexible display device can be folded or rolled into a scroll form to maximize portability and can be used in various fields.

A flexible display device includes a flexible display panel. Examples of the flexible display panels include organic light emitting diode display panels, liquid crystal display panels, and electrophoretic display (EPD) panels.

However, since the flexible display device itself is bent, rolled, or folded, the display panel included in the device also receives bending stress. In addition, when the display panel receives a bending stress of a certain level or more, a serious problem occurs in that cracks occur.

Accordingly, in recent years, research on thinner, lighter, bendable or foldable touch sensors and displays using polymer films that replace glass substrates has been actively conducted.

In order to increase the flexible characteristics of the touch sensor, it is necessary to reduce the thickness of the insulating layer or passivation layer that protects internal components, but there is a problem in that the durability of the touch sensor is reduced in proportion to the thickness decrease of the insulating layer or the passivation layer.

Therefore, a technique capable of improving the flexible characteristics of the touch sensor while maintaining durability is required.

Republic of Korea Patent Publication No. 10-2012-0008153 (published date: January 30, 2012, name: capacitive touch sensor and its manufacturing method) Republic of Korea Patent Publication No. 10-2012-0069226 (published date: June 28, 2012, name: touch sensor and its manufacturing method)

The present invention has been made to solve the above problems of the prior art, and an object of the present invention is to provide a flexible touch sensor and a manufacturing method thereof capable of improving flexible characteristics while maintaining durability.

The present invention is a base layer; a first sensing pattern formed on the substrate layer with unit patterns spaced apart in a first direction and a second sensing pattern formed in a second direction and connected through a joint portion; a bridge electrode connecting spaced apart unit patterns of the sensing first pattern; an insulating layer interposed between the first and second sensing patterns and the bridge electrode and having a contact hole; The insulating layer provides a flexible touch sensor including a first region formed on the first and second detection patterns, and a second region having a thickness smaller than the first region and formed above the gap of the unit pattern. .

In the flexible touch sensor according to the present invention, the thickness of the insulating layer may be 0.5 μm or more and 5 μm or less.

In the flexible touch sensor according to the present invention, the minimum thickness of the first region may be 0.5 μm or more.

In the flexible touch sensor according to the present invention, the second region may have a thickness of 1.5 μm or more and 5 μm or less.

In the flexible touch sensor according to the present invention, a passivation layer formed on top of the touch sensor layer may be further included.

In the flexible touch sensor according to the present invention, the thickness of the third region formed along one direction of the passivation layer may be smaller than that of regions other than the third region.

In the flexible touch sensor according to the present invention, the third area may have a patterned inclined surface shape in which the thickness becomes thinner as it approaches a folding line.

The third region may have a curved shape in which a thickness becomes thinner as it approaches a folding line.

The minimum thickness of the third region may be 0.5 μm or more.

The present invention includes a sensing pattern forming step of forming a first sensing pattern formed on a base layer with unit patterns spaced apart in a first direction and a second sensing pattern formed in a second direction and connected to each other through a joint;

a first region formed on the first and second detection patterns using a halftone mask, and a second region thinner than the first region and formed above the unit pattern gap; an insulating layer forming step of forming an insulating layer having holes; and

It provides a flexible touch sensor manufacturing method comprising the step of forming a bridge electrode connecting spaced unit patterns of the first sensing pattern on the insulating layer.

In the flexible touch sensor manufacturing method according to the present invention, a passivation forming step of forming a material layer for forming passivation on the upper portion of the touch sensor layer may be further included.

In the flexible touch sensor manufacturing method according to the present invention, in the passivation forming step, the thickness of the third region formed along one direction using a halftone mask (M2) is thinner than the region other than the third region passivation can be formed.

The present invention provides a flexible touch sensor capable of improving flexible characteristics while maintaining durability and a manufacturing method thereof.

1 is a diagram schematically showing the overall planar shape of a general flexible touch sensor.
2 is an enlarged view of a portion of the present invention corresponding to area A of a general flexible touch sensor.
FIG. 3 is a view showing an insulating layer in FIG. 2 .
4 and 5 are cross-sectional views of flexible touch sensors according to an embodiment of the present invention.
6 to 12 are process cross-sectional views of a manufacturing method of flexible touch sensors according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the following examples are intended to illustrate the present invention, and the present invention is not limited by the following examples and can be variously modified and changed. Prior to describing the present invention, if it is determined that a detailed description of a related known function and configuration may unnecessarily obscure the gist of the present invention, the description thereof will be omitted.

The following description and drawings illustrate specific embodiments so that those skilled in the art may readily implement the described devices and methods. Other embodiments may include structurally and logically other variations. Individual components and functions may generally be chosen unless explicitly required, and the order of the process may vary. Portions and features of some embodiments may be included in or substituted for other embodiments.

Specific structural or functional descriptions of the embodiments according to the concept of the present invention disclosed in this specification are only illustrated for the purpose of explaining the embodiments according to the concept of the present invention, and the embodiments according to the concept of the present invention It can be embodied in various forms and is not limited to the embodiments described herein.

Embodiments according to the concept of the present invention can apply various changes and have various forms, so the embodiments are illustrated in the drawings and described in detail in this specification. However, this is not intended to limit the embodiments according to the concept of the present invention to specific disclosure forms, and includes all changes, equivalents, or substitutes included in the spirit and technical scope of the present invention.

Terms such as first or second may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another, e.g. without departing from the scope of rights according to the concept of the present invention, a first component may be termed a second component and similarly a second component may be termed a second component. A component may also be referred to as a first component.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when a component is referred to as “directly connected” or “directly connected” to another component, it should be understood that no other component exists in the middle. Other expressions describing the relationship between components, such as "between" and "directly between" or "adjacent to" and "directly adjacent to", etc., should be interpreted similarly.

Terms used in this specification are used only to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "having" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in this specification, but one or more other features It should be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this specification, it should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram schematically showing the overall planar shape of a general flexible screen sensor.

Referring to FIG. 1 , a general flexible touch sensor may be divided into a display area and a non-display area based on whether visual information is displayed. In FIG. 1, it should be noted that the non-display area is expressed larger than the actual size in order to improve the visibility of components provided in the non-display area.

The display area is an area where an image provided by a device coupled to the touch sensor is displayed and a touch signal input from the user is sensed in a capacitive manner. Components including patterns are formed.

Electrode pads electrically connected to the sensing pattern, sensing lines electrically connected to the electrode pads, and bonding pads electrically connected to the sensing lines are formed in the non-display area located outside the display area. . A flexible printed circuit (FPC) that transmits a touch signal detected in the display area to a driving unit (not shown) is connected to the bonding pad.

2 is an enlarged view of a portion of the present invention corresponding to area A of a general flexible touch sensor.

FIG. 2 is an enlarged view of area A shown in FIG. 1 .

Referring additionally to FIG. 2, a planar shape of a touch sensor layer constituting a flexible touch sensor according to an embodiment of the present invention is disclosed, and a unit pattern of the touch sensor layer is spaced apart in a first direction on the base layer a first sensing pattern 41 formed and a second sensing pattern 42 formed in a second direction and having unit patterns connected through a joint; a bridge electrode 47 connecting unit patterns spaced apart from the first pattern; an insulating layer 45 interposed between the first and second sensing patterns and the bridge electrode and having contact holes 43a and 43b; The insulating layer includes a first area (not shown in FIG. 2 ) formed on the first and second sensing patterns and a second area (not shown in FIG. 44b)

The first sensing patterns 41 are formed along a first direction while being electrically separated from each other, and the second sensing patterns 42 are formed along a second direction while being electrically connected to each other through a joint, The second direction is a direction crossing the first direction. For example, when the first direction is the X direction, the second direction may be the Y direction. The insulating layer 45 including the first region 44a and the second region 44b is interposed between the first and second detection patterns 41 and 42 and the bridge electrode 47 . The bridge electrode 47 electrically connects adjacent first sensing patterns 41 through contact holes 43a and 43b.

The first area may be formed on the first sensing pattern 41 and the second sensing pattern 42 . The second area may be formed between unit patterns of the first sensing pattern 41 and the second sensing pattern 42 .

In the present invention, by forming the second area without the sensing electrode (pattern) thinner than the first area, it is possible to provide a touch sensor having excellent durability and improved flexible characteristics.

In FIGS. 2 and 3 , the second area is shown as a cut off between the first and second sensing patterns 41 and 42 , but this is only an example and may have a non-breaking structure.

4 and 5, the third region 64 is flexible while maintaining durability by making the thickness of the passivation layer formed on the upper front surface of the touch sensor layer after forming the bridge electrode thinner in a specific region, preferably in the folding region, than in other regions. characteristics can be improved. In addition, due to the difference in thickness of the insulating layer including the first region 44a and the second region 44b, when the passivation layer is formed with the same thickness on the upper part of the touch sensor layer, the passivation occurs in the portion corresponding to the second region 44b. Curvature of the layer may be formed.

The curved part means a curved shape in the window or display itself in the final product configuration. It refers to a region that is fixed in a bent state or where bending is repeated, and a folded portion of the bent portion as shown in the dotted line in FIG. 2 is referred to as a folding line.

FIG. 3 is a view showing an insulating layer according to an embodiment of the present invention including the contact holes 44a and 44b, the first region 44a, and the second region 44b in FIG. 2 .

4 is a cross-sectional view of flexible screen sensors according to an embodiment of the present invention.

Referring to FIG. 4 , the flexible screen sensor according to an embodiment of the present invention includes a base layer 10 , a touch sensor layer 40 and a passivation layer 60 .

The base layer 10 is a base on which components of the touch sensor are formed, and may be a transparent material having a hard or flexible material, and may be, for example, a transparent optical film or a polarizing plate in the case of a soft material.

The transparent optical film may be a film having excellent transparency, mechanical strength, and thermal stability, and specific examples include polyester-based resins such as polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, and polybutylene terephthalate; cellulosic resins such as diacetyl cellulose and triacetyl cellulose; polycarbonate-based resin; acrylic resins such as polymethyl (meth)acrylate and polyethyl (meth)acrylate; styrenic resins such as polystyrene and acrylonitrile-styrene copolymer; polyolefin-based resins such as polyethylene, polypropylene, polyolefins having a cyclo-based or norbornene structure, and ethylene-propylene copolymers; vinyl chloride-based resins; amide resins such as nylon and aromatic polyamide; imide-based resins; polyethersulfone-based resins; sulfone-based resins; polyether ether ketone-based resins; sulfurized polyphenylene-based resins; vinyl alcohol-based resin; vinylidene chloride-based resins; vinyl butyral-based resins; allylate-based resins; polyoxymethylene-based resin; A film composed of a thermoplastic resin such as an epoxy resin may be used, and a film composed of a blend of the thermoplastic resin may also be used. In addition, a film made of a thermosetting resin or an ultraviolet curable resin such as (meth)acrylic, urethane, acrylurethane, epoxy, or silicone may be used. The thickness of such a transparent optical film may be appropriately determined, but generally may be determined to be 1 to 500 μm in consideration of workability such as strength and handling, and thin layer properties. It is especially preferably 1 to 300 μm, and more preferably 5 to 200 μm.

Such a transparent optical film may contain one or more appropriate additives. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, colorants and the like. The transparent optical film may have a structure including various functional layers such as a hard coating layer, an antireflection layer, and a gas barrier layer on one or both sides of the film, and the functional layer is not limited to the above, and various functional layers may be used depending on the purpose can include

Also, if necessary, the transparent optical film may be surface-treated. Examples of such surface treatment include dry treatment such as plasma treatment, corona treatment, and primer treatment, chemical treatment such as alkali treatment including saponification treatment, and the like.

In addition, the transparent optical film may be an isotropic film, a retardation film, or a protective film.

In the case of an isotropic film, the in-plane retardation (Ro, Ro=[(nx-ny)×d], nx, ny is the principal refractive index in the film plane, and d is the film thickness) is 40 nm or less, preferably 15 nm or less, and the thickness Directional retardation (Rth, Rth=[(nx+ny)/2-nz]×d, nx, ny is the principal refractive index in the film plane, nz is the refractive index in the film thickness direction, and d is the film thickness) is -90 nm to +75 nm, preferably -80 nm to +60 nm, particularly preferably -70 nm to +45 nm.

Retardation film is a film manufactured by uniaxial stretching, biaxial stretching, polymer coating, and liquid crystal coating of a polymer film, and is generally used to improve and control optical properties such as compensation for viewing angle, color improvement, light leakage, and color taste control of a display. do. Types of the retardation film include a 1/2 or 1/4 wave plate, a positive C plate, a negative C plate, a positive A plate, a negative A plate, and a biaxial wave plate.

The protective film may be a film including an adhesive layer on at least one surface of a film made of polymer resin or a film having self-adhesive properties such as polypropylene, and may be used to protect the touch sensor surface and improve processability.

As the polarizing plate, a known polarizing plate used in a display panel may be used. Specifically, a polyvinyl alcohol film is stretched to provide passivation on at least one side of a polarizer dyed with iodine or a dichroic dye, a liquid crystal is oriented to have the performance of a polarizer, polyvinyl alcohol on a transparent film and those made by coating an orientation resin such as, stretching, and dyeing it, but are not limited thereto.

The touch sensor layer 40 is formed on the base layer 10 and is a component for sensing a touch signal input by a user.

The detection pattern constituting the touch sensor layer 40 may be formed in an appropriate shape according to the needs of the electronic device to which it is applied. For example, when applied to a touch sensor, a pattern for detecting x coordinates and a pattern for detecting y coordinates It may be formed of two types of patterns of patterns to do, but is not limited thereto.

For example, the touch sensor layer 40 includes a first sensing pattern 41 formed by spaced unit patterns in a first direction on the base layer and a second sensing pattern formed in a second direction and connected through a joint portion. pattern 42; a bridge electrode 47 connecting unit patterns spaced apart from the first pattern; an insulating layer 45 interposed between the first and second sensing patterns and the bridge electrode and having contact holes 43a and 43b; The insulating layer includes a first area (not shown in FIG. 2 ) formed on the first and second sensing patterns and a second area (not shown in FIG. 44b).

The first sensing pattern 41, the second sensing pattern 42, and the bridge electrode 47 may be used without limitation as long as they are transparent conductive materials, for example, indium tin oxide (ITO) or indium zinc oxide (IZO). , Indium Zinc Tin Oxide (IZTO), Aluminum Zinc Oxide (AZO), Gallium Zinc Oxide (GZO), Florin Tin Oxide (FTO), Indium Tin Oxide-Silver-Indium Tin Oxide (ITO-Ag-ITO), Indium Zinc Oxide -Silver-indium zinc oxide (IZO-Ag-IZO), indium zinc tin oxide-silver-indium zinc tin oxide (IZTO-Ag-IZTO) and aluminum zinc oxide-silver-aluminum zinc oxide (AZO-Ag-AZO) metal oxides selected from the group consisting of; metals selected from the group consisting of gold (Au), silver (Ag), copper (Cu), molybdenum (Mo) and APC (Ag-Pd-Cu); nanowires of a metal selected from the group consisting of gold, silver, copper and lead; carbon-based materials selected from the group consisting of carbon nanotubes (CNT) and graphene; and poly(3,4-ethylenedioxythiophene) (PEDOT) and polyaniline (PANI). Preferably, indium tin oxide may be used. Both crystalline and amorphous indium tin oxide can be used.

The thickness of the touch sensor layer 40 is not particularly limited, but is preferably as thin as possible in consideration of flexibility of the touch sensor.

For example, the first sensing pattern 41 and the second sensing pattern 42 constituting the touch sensor layer 40 may be a polygonal pattern such as a triangular, quadrangular, pentagonal, hexagonal, or heptagon independently of each other. can

Also, for example, the touch sensor layer 40 may include a regular pattern. A regular pattern means that the shape of a pattern has regularity. For example, the detection patterns may independently include patterns in a shape of a mesh such as a rectangle or a square or a shape of a hexagon.

Also, for example, the touch sensor layer 40 may include an irregular pattern. An irregular pattern means that the shape of a pattern does not have regularity.

Also, for example, when the sensing pattern constituting the touch sensor layer 40 is formed of a material such as metal nanowires, carbon-based materials, or polymer materials, the sensing pattern may have a network structure. When the sensing patterns have a network structure, since signals are sequentially transferred to adjacent patterns by contacting each other, a pattern having high sensitivity can be realized.

For example, the sensing pattern constituting the touch sensor layer 40 may be formed of a single layer or a plurality of layers.

As a material of the insulating layer 45 including the first region and the second region insulating the first detection pattern 41 and the second detection pattern 42, an insulating material known in the art may be used without limitation. , For example, materials excellent in transparency, flexibility, mechanical strength, thermal stability, moisture barrier properties, isotropy, etc. can be used.

For a specific example, an organic insulating film may be applied as a material for the insulating layer 45, and may be formed of a curable composition including a polyol and a melamine curing agent, but is not limited thereto.

Specific types of polyol include, but are not limited to, polyether glycol derivatives, polyester glycol derivatives, and polycaprolactone glycol derivatives.

Specific types of melamine curing agents include methoxy methyl melamine derivatives, methyl melamine derivatives, butyl melamine derivatives, isobutoxy melamine derivatives and butoxy melamine derivatives and the like, but are not limited thereto.

As another example, the insulating layer 45 may be formed of an organic-inorganic hybrid curable composition, and when an organic compound and an inorganic compound are simultaneously used, it is preferable in that cracks generated during peeling can be reduced.

As the organic compound, the aforementioned components may be used, and as the inorganic material, silica-based nanoparticles, silicon-based nanoparticles, glass nanofibers, and the like may be used, but are not limited thereto.

According to an embodiment, the thickness (h ₃ ) of the first region may be greater than the thickness (h ₁ +h ₂ ) of the second region.

According to an embodiment of the present invention, in order to secure the flexible characteristics of the touch sensor, the thickness of the insulating layer 45 is not reduced as a whole and only the thickness (h _{1 +} h ₂ ) of the second region 44b is reduced to a certain level. , It is possible to secure the flexible characteristics while satisfying the durability requirements of the touch sensor.

For example, the thickness of the insulating layer 45 including the first region 44a and the second region 44b is preferably 0.5 μm or more and 5 μm or less. If the thickness of the insulating layer 45 is less than 0.5 μm, the risk of dielectric breakdown and durability degradation increases. When the thickness of the insulating layer 45 exceeds 5 μm, the flexible characteristics of the touch sensor are deteriorated and the uniformity of the insulating layer 45 including the first region 44a and the second region 44b is greatly reduced. The performance quality of the touch sensor is degraded.

For example, the minimum thickness (h ₁ +h ₂ ) of the second region is preferably 0.5 μm or more and 1.5 μm or less. If the thickness of the second region (h ₁ +h ₂ ) is less than 0.5 μm, as the user repeats folding and unfolding of the touch sensor, cracks occur in the insulating layer 45, resulting in reduced durability of the touch sensor. do. When the thickness of the first region (h ₁ +h ₂ ) exceeds 1.5 μm, the flexible characteristics of the touch sensor are deteriorated.

For example, the thickness of the first region is preferably 1.5 μm or more and 5 μm or less. When the thickness (h ₃ ) of the first region 44a is less than 1.5 μm, the durability of the insulating layer 45 including the first region 44a is weakened so that the touch sensor layer 40 is prevented from external factors such as impact. If the elements constituting the can not be sufficiently protected, and the thickness (h ₃ ) of the first region exceeds 5 μm, the flexible characteristics of the touch sensor are deteriorated and the insulating layer 45 including the first region 44a The uniformity is greatly degraded, which degrades the performance quality of the touch sensor.

Regarding the thicknesses of the first and second regions, the thickness of the first region (h ₃ ) is configured to be thicker than the thickness of the second region (h ₁ +h ₂ ), thereby maintaining durability of the touch sensor and flexible characteristics can be further improved.

Examples of specific shapes of the second region 44b are described below.

As an example, as shown in FIG. 4 , the second region 44b may have a planar shape.

In addition to these examples, the second region 44b may have various shapes capable of securing durability and flexibility of the insulating layer 45 .

The passivation layer 60 shown in FIG. 4 is formed on the touch sensor layer 40 .

The passivation layer 60 is formed of an insulating material and covers the first sensing pattern 41, the second sensing pattern 42, the insulating layer 45, and the bridge electrode 47 constituting the touch sensor layer 40. formed so as to insulate and protect the touch sensor layer 40 from the outside. For example, the passivation layer 60 may be formed of a single layer or a plurality of layers of two or more layers.

For example, it is preferable that the thickness of the passivation layer 60 is 0.5 μm or more and 5 μm or less. If the thickness of the passivation layer 60 is less than 0.5 μm, the risk of corrosion of lower components increases due to a decrease in the moisture permeability of the passivation layer 60, If the elements constituting the touch sensor layer 40 cannot be sufficiently protected from external factors such as impact, and the thickness of the passivation layer 60 exceeds 5 μm, the flexible characteristics of the touch sensor deteriorate and the passivation layer ( 60) is greatly deteriorated, which degrades the performance quality of the touch sensor.

As the material of the passivation layer 60, an insulating material known in the art may be used without limitation, and for example, a material having excellent transparency, flexibility, mechanical strength, thermal stability, moisture barrier property, and isotropy may be used.

For a specific example, an organic insulating film may be applied as a material for the passivation layer 60, and may be formed of a curable composition including polyol and a melamine curing agent, but is not limited thereto.

Specific types of polyol include, but are not limited to, polyether glycol derivatives, polyester glycol derivatives, and polycaprolactone glycol derivatives.

Specific types of melamine curing agents include methoxy methyl melamine derivatives, methyl melamine derivatives, butyl melamine derivatives, isobutoxy melamine derivatives and butoxy melamine derivatives and the like, but are not limited thereto.

As another example, the passivation layer 60 may be formed of an organic-inorganic hybrid curable composition, and when an organic compound and an inorganic compound are simultaneously used, it is preferable in that cracks generated during peeling can be reduced.

As the organic compound, the aforementioned components may be used, and as the inorganic material, silica-based nanoparticles, silicon-based nanoparticles, glass nanofibers, and the like may be used, but are not limited thereto.

5 is a cross-sectional view of flexible touch sensors according to an embodiment of the present invention.

Referring to FIG. 5 , the flexible touch sensor according to an embodiment of the present invention includes a base layer 10 , a touch sensor layer 40 and a passivation layer 62 .

In the flexible touch sensor according to FIG. 5, the base layer 10 and the touch sensor layer 40 are substantially the same as the flexible touch sensor according to FIG. 4, and the passivation layer 62 includes the third region 64 There is a difference in

The minimum thickness h ₄ of the third region shown in FIG. 5 is preferably 0.5 μm or more and 1.5 μm or less. If it is less than 0.5 μm, the durability of the touch sensor may be deteriorated, and if it exceeds 1.5 μm, the flexible characteristics of the touch sensor are deteriorated and the uniformity is greatly deteriorated, thereby degrading the performance quality of the touch sensor.

For example, the thickness (h ₅ ) of the region other than the third region is preferably 1.5 μm or more and 5 μm or less. If the thickness (h ₅ ) of the area other than the third area is less than 1.5 μm, the durability of the passivation layer 62 is weakened, so that the elements constituting the touch sensor layer 40 cannot be sufficiently protected from external factors such as impact. , If the thickness exceeds 5 μm, the flexible property of the touch sensor is deteriorated and the uniformity of the passivation layer 62 is greatly deteriorated, resulting in degraded performance quality of the touch sensor.

When the user folds the touch sensor, the thickness (h ₄ ) of the third area, which becomes the folding line, which is the line where the touch sensor is folded, is smaller than the thickness (h ₅ ) of areas other than the third area, thereby maintaining durability of the touch sensor. At the same time, the flexible characteristics can be further improved.

Examples of specific shapes of the third region are described below.

As one example, as disclosed in FIG. 5 , the third region may have a planar shape.

As another example, the third region may have an inclined plane shape in which the thickness becomes thinner as it approaches the folding line.

As another example, the third region may have a curved shape in which the thickness decreases as it approaches the folding line.

6 to 12 are process cross-sectional views of a manufacturing method of flexible touch sensors according to an embodiment of the present invention.

First, as disclosed in FIG. 6 , a first sensing pattern 41 formed on a base layer with unit patterns spaced apart in a first direction and a second sensing pattern 42 formed in a second direction and connected through a joint portion ) is performed. The first sensing patterns 41 are formed along a first direction while being electrically separated from each other, and the second sensing patterns 42 are formed along a second direction while being electrically connected to each other through a joint, The second direction is a direction crossing the first direction. For example, when the first direction is the X direction, the second direction may be the Y direction.

7 and 8, the first region 44a formed on the first and second detection patterns 41 and 42 using a halftone mask (M1) and the An insulating layer forming process is performed to form an insulating layer having a second region 44b having a thickness smaller than that of region 1 and formed above the unit pattern gap and having contact holes 43a and 43b.

Specifically, as shown in FIG. 7 , a process of forming a material layer 50 for forming an insulating layer between the first sensing pattern 41 and the second sensing pattern 42 is performed.

Next, as shown in FIG. 7, in a state in which a halftone mask (M1) is disposed on the material layer 50 for forming an insulating layer, the material for forming an insulating layer is used by using the halftone mask (M). A process of differentially exposing and developing the layer 50 is performed. Through this, as shown in FIG. 8 , the insulating layer 45 including the contact holes 43a and 43b and the first region 44a and the second region 44b having different thicknesses can be obtained.

The half-tone mask M1 is composed of a light-transmitting substrate and a semi-transmitting portion and a light-blocking portion formed thereon. The transflective portion may use MoSiN, MoSi, MoSiO, MoSiON, CrSi, or the like. The light-blocking portion can be formed using a light-blocking material that absorbs light, such as chromium or chromium oxide.

When the halftone mask M1 is irradiated with exposure light, the light transmittance is 0% in the light-shielding portion, and the light transmittance is 100% in the region where the light-shielding portion and the semi-transmissive portion are not formed. In addition, in the semipermeable part, it can be adjusted in the range of 10 to 80%. Adjustment of the transmittance of light in the semi-transmissive portion can be adjusted by the material of the semi-transmissive portion.

The halftone mask M1 has a light transmittance pattern corresponding to the shape of the target pattern. That is, when the light emitted from the exposure device reaches the halftone mask M1, the light reaching the halftone mask M forms the halftone mask M in response to the light transmittance pattern of the halftone mask M. Since the light passes through and reaches the insulating layer forming material layer 50, the insulating layer forming material layer 50 is exposed to light corresponding to the light transmittance pattern of the half-tone mask M.

For example, considering the thickness of the finally formed insulating layers 60 and 62 , the material layer 50 for forming the insulating layer may be formed to a thickness of 5 μm or less.

7 and 8 each show an example in which the second region 44b, which can be obtained through the step of forming the insulating layer 45 using the halftone mask M1, has a planar shape.

Next, as shown in FIG. 9 , a process of forming a bridge electrode connecting spaced unit patterns of the first sensing pattern 42 on the insulating layer is performed. That is, a process of forming a bridge electrode 47 electrically connecting adjacent first sensing patterns 42 is performed.

The thickness of the touch sensor layer 40 is not particularly limited, but is preferably as thin as possible in consideration of flexibility of the touch sensor.

For example, the first sensing pattern 41 and the second sensing pattern 42 constituting the touch sensor layer 40 may be a polygonal pattern such as a triangular, quadrangular, pentagonal, hexagonal, or heptagon independently of each other. can

Also, for example, the touch sensor layer 40 may include a regular pattern. A regular pattern means that the shape of a pattern has regularity. For example, the detection patterns may independently include patterns in a shape of a mesh such as a rectangle or a square or a shape of a hexagon.

Also, for example, the touch sensor layer 40 may include an irregular pattern. An irregular pattern means that the shape of a pattern does not have regularity.

Also, for example, when the sensing pattern constituting the touch sensor layer 40 is formed of a material such as metal nanowires, carbon-based materials, or polymer materials, the sensing pattern may have a network structure. When the sensing patterns have a network structure, since signals are sequentially transferred to adjacent patterns by contacting each other, a pattern having high sensitivity can be realized.

For example, the sensing pattern constituting the touch sensor layer 40 may be formed of a single layer or a plurality of layers.

As the material of the insulating layer 45 that insulates the first sensing pattern 41 and the second sensing pattern 42, an insulating material known in the art may be used without limitation, and for example, transparency, flexibility, mechanical Materials with excellent strength, thermal stability, moisture barrier properties, and isotropic properties may be used.

Next, passivation layers 60 and 62 are formed by forming a material layer for forming passivation on the touch sensor layer.

10 shows a passivation layer forming step corresponding to an embodiment in which the thickness of only the insulating layer is differently formed for each region according to an embodiment of the present invention, and the passivation layer having the same thickness due to the difference in thickness of the insulating layer Also, according to the curve of the insulating layer, it is not flat, but is formed to have a curved shape.

11 and 12 show a first area formed on the first sensing pattern and the second sensing pattern and a second area thinner than the first area and formed on the unit pattern gap according to an embodiment of the present invention. A step of forming a passivation layer corresponding to an embodiment including an insulating layer including an insulating layer and a passivation layer having a thickness of a third region formed along one direction and having a thickness smaller than that of regions other than the third region is shown.

Referring to FIG. 10 , a passivation layer 62 is formed on the touch sensor layer 40 by using a material layer for forming passivation.

Referring to FIG. 11, a state in which a material layer 61 for forming passivation is formed on the touch sensor layer 40, and a halftone mask (M2) is disposed on the material layer 61 for forming passivation. , a process of differentially exposing and developing the material layer 61 for forming passivation using the halftone mask M is performed. Through this, as shown in FIG. 12 , it is possible to obtain a passivation layer 62 having different heights between a third region formed along one direction and a region other than the third region.

The half-tone mask M2 is composed of a light-transmitting substrate and a semi-transmissive portion and a light-blocking portion formed thereon. The transflective portion may use MoSiN, MoSi, MoSiO, MoSiON, CrSi, or the like. The light-blocking portion can be formed using a light-blocking material that absorbs light, such as chromium or chromium oxide.

When the halftone mask M2 is irradiated with exposure light, the light transmittance is 0% in the light-shielding portion, and the light transmittance is 100% in the region where the light-shielding portion and semi-transmissive portion are not formed. Further, in the semi-permeable portion, it can be adjusted in the range of 10 to 80%. Adjustment of the transmittance of light in the semi-transmissive portion can be adjusted by the material of the semi-transmissive portion.

The halftone mask M2 has a light transmittance pattern corresponding to the shape of the target pattern. That is, when the light emitted from the exposure device reaches the halftone mask M, the light reaching the halftone mask M forms the halftone mask M in response to the light transmittance pattern of the halftone mask M. Since the passivation formation material layer 61 is transmitted through the light, the passivation formation material layer 61 is exposed corresponding to the light transmittance pattern of the half-tone mask M.

For example, considering the thickness of the passivation that is finally formed, the material layer 61 for forming passivation may be formed to a thickness of 5 μm or less.

11 and 12 each show an example in which the third region, which can be obtained through the step of forming the passivation layers 60 and 62 using the halftone mask M2, has a planar shape.

Although not shown in the drawing, the third region may have an inclined plane shape in which the thickness becomes thinner as it approaches a folding line.

Although not shown in the drawing, the third region may have a curved shape in which the thickness becomes thinner as it approaches the folding line.

11 and 12 only disclose examples of the shape of the first region of the passivation layers 60 and 62, and in addition to these examples, the third region can secure durability and flexible characteristics of the passivation layers 60 and 62. It can have various shapes.

6 to 12 exemplarily describe embodiments in which the bridge electrode 47 is formed after first forming the first sensing pattern 41 and the second sensing pattern 42, and after forming the bridge electrode The present invention may also be applied to embodiments in which the first sensing pattern and the second sensing pattern are formed.

As described in detail above, according to the present invention, there is an effect of providing a flexible touch sensor capable of improving flexible characteristics while maintaining durability and a manufacturing method thereof.

10: base layer
40: touch sensor layer
41: first detection pattern
42: second detection pattern
43a, 43b: contact hole
44a: first area
44b: second area
45: insulating layer
46: bend
47: bridge electrode
61: material layer for forming passivation
60, 62: passivation layer
64 third area
M: Halftone Mask

Claims (12)

base layer; And a flexible touch sensor comprising a touch sensor layer,
The touch sensor layer,
a first sensing pattern formed on the base layer with unit patterns spaced apart in a first direction and a second sensing pattern formed in a second direction and connected through a joint portion;
a bridge electrode connecting spaced apart unit patterns of the first sensing pattern; and
An insulating layer interposed between the first and second sensing patterns and the bridge electrode and having a contact hole;
The thickness of the insulating layer is 0.5 μm or more and 5 μm or less,
The insulating layer includes a first region formed on the first sensing pattern and the second sensing pattern, and a second region having a thickness thinner than the first area and formed above the gap of the unit pattern. delete According to claim 1,
The flexible touch sensor, characterized in that the minimum thickness of the second region is 0.5㎛ or more. The flexible touch sensor of claim 1 , wherein the first region has a thickness of 1.5 μm or more and 5 μm or less. According to claim 1,
A flexible touch sensor further comprising a passivation layer formed on the touch sensor layer. According to claim 5,
The passivation layer is characterized in that the thickness of the third region formed along one direction is thinner than the thickness of regions other than the third region,
The third area corresponds to a folding area of the flexible touch sensor. According to claim 6,
The flexible touch sensor, characterized in that the third region has a pattern inclined surface shape in which the thickness becomes thinner as it approaches a folding line. According to claim 6,
The flexible touch sensor, characterized in that the third region has a curved shape in which the thickness becomes thinner as it approaches a folding line. According to claim 6,
The flexible touch sensor, characterized in that the minimum thickness of the third region is 0.5㎛ or more. a sensing pattern forming step of forming a first sensing pattern formed on a substrate layer with unit patterns spaced apart in a first direction and a second sensing pattern formed in a second direction and connected to each other through a joint;
A first region formed on the first and second detection patterns using a halftone mask (M1) and a second region thinner than the first region and formed above the unit pattern gap. an insulating layer forming step of forming an insulating layer having a contact hole; and
And a bridge electrode forming step of connecting spaced unit patterns of the first sensing pattern on the insulating layer,
The thickness of the insulating layer is 0.5㎛ or more and 5㎛ or less, flexible touch sensor manufacturing method. According to claim 10,
Further comprising a passivation forming step of forming a material layer for forming passivation on the touch sensor layer including the first sensing pattern, the second sensing pattern, the insulating layer and the bridge electrode, the flexible touch sensor manufacturing method. According to claim 11,
In the passivation forming step,
Characterized in that the passivation is formed so that the thickness of the third region formed along one direction is thinner than the region other than the third region using a halftone mask (M2),
The third region corresponds to a folding region of the flexible touch sensor, a flexible touch sensor manufacturing method.

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