KR20230127633A - Digitizer Panel with Integral Shield Layer and Display Including the Same - Google Patents

Abstract

A digitizer panel having an integrated shielding layer includes a digitizer including a substrate layer and an electrode layer on an upper surface of the substrate layer and a shielding layer deposited on a lower surface of the substrate layer.

Description

Digitizer panel with integral shielding layer and image display device having the same

The present invention relates to a digitizer panel, and more particularly, to a digitizer panel capable of improving bending characteristics and reducing manufacturing cost by integrally configuring a shielding layer.

Most image display devices (Display) apply a touch input method in which a user directly touches and inputs a screen using a finger or an electronic pen.

In the touch input method, a user can input by directly touching a specific location on the screen, thereby providing an intuitive and convenient user interface. In particular, a touch input method using a pen can designate more precise coordinates than a touch input method using a finger, so it is suitable for graphic work such as CAD.

A digitizer refers to a device that converts the coordinates of a pen into digital data and inputs them. Depending on the method of detecting the coordinates, there are a resistive method, a capacitive method, and an electromagnetic resonance (EMR) method.

1 is a cross-sectional view showing a prior art digitizer panel.

As shown in FIG. 1, a conventional digitizer panel is composed of a digitizer 10 and an attachable shielding layer 20 attached to the rear surface of the digitizer 10. Here, the digitizer 10 includes a base layer 11, a digitizer adhesive layer 12, a lower electrode layer 13, an interlayer insulating layer 14, an upper electrode layer 15, a passivation layer 16, and the like.

As shown in FIG. 1, the conventional digitizer panel has a shielding adhesive layer 30 such as a pressure sensitive adhesive (PSA) film on the rear surface of the digitizer 10 as a medium, and an attachable shielding layer (20) in the form of a plate or film. ) is attached to shield electromagnetic waves, where the film-type attachable shielding layer 20 is a film-type shielding layer in which a thin metal layer of conductive metal such as silver, nickel, copper, etc. is formed on a film of ordinary polymer material. are using

On the other hand, as for recent image display devices, flexible displays that can be folded or bent are in the limelight. As a result, characteristics such as flexibility, bendability, and durability that can be applied to flexible displays are also required for digitizer panels.

By the way, the conventional digitizer panel shown in FIG. 1 takes a method of attaching the attachable shielding layer 20 to the back of the digitizer 10 via the shielding adhesive layer 30, and there is a limit to reducing the thickness, further It is difficult to meet the characteristics of flexibility, bendability, and durability required by flexible displays, such as frequent cracks in the folding portion.

The present invention is to solve the problems of the prior art, and to provide a digitizer panel that can satisfy the characteristics of flexibility, bendability, and durability required by flexible displays, and further reduce manufacturing costs.

The digitizer panel of the present invention for achieving this object may include a digitizer and a shielding layer.

The digitizer may include a substrate layer and an electrode layer on an upper surface of the substrate layer.

The shielding layer may include a shielding layer deposited on the lower surface of the base layer.

In the digitizer panel of the present invention, the substrate layer and the shielding layer may include a folding portion.

In the digitizer panel of the present invention, the shielding layer may have a reduced thickness at the folding portion.

In the digitizer panel of the present invention, the shielding layer may include titanium (Ti), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), barium (Ba), or an alloy of two or more of these. there is.

In the digitizer panel of the present invention, the shielding layer may further contain oxygen.

In the digitizer panel of the present invention, the shielding layer may have a film density of 6 to 7 g/cm 3 .

In the digitizer panel of the present invention, the shielding layer may have an internal/external strain of 0.1% to 1%.

In the digitizer panel of the present invention, the shielding layer may have a thickness of 400 to 800 nm.

An image display device according to the present invention may include a display panel and a digitizer panel having the above-described shielding layer disposed below the display panel.

The image display device according to the present invention may further include a rear cover. In this case, a digitizer panel having a shielding layer may be disposed between the display panel and the rear cover.

The digitizer panel of the present invention having such a configuration can minimize the thickness by integrally forming the shielding layer on the back side of the digitizer through deposition (sputtering, etc.), and through this, flexibility and flexibility required for flexible displays can be greatly improved. .

In the digitizer panel of the present invention, since the shielding layer is integrally formed on the rear surface of the digitizer, durability of the digitizer can be greatly improved in a curved environment of a flexible display.

In addition, the digitizer panel of the present invention can freely adjust the thickness by forming a shielding layer on the back side of the digitizer through deposition (sputtering, etc.), and furthermore, the cost of forming a shielding layer on the digitizer panel can be reduced, thereby increasing manufacturing competitiveness.

1 is a cross-sectional view showing a prior art digitizer panel.
2 is a cross-sectional view showing a digitizer panel of the present invention.
3 and 4 are cross-sectional views showing modified examples of the digitizer panel of the present invention.

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

2 is a cross-sectional view showing a digitizer panel of the present invention.

As shown in FIG. 2 , the digitizer panel of the present invention may include a digitizer 100 and an integral shielding layer 200 .

The digitizer 100 may include a base layer 110, a digitizer adhesive layer 120, a lower electrode layer 130, an interlayer insulating layer 140, an upper electrode layer 150, a passivation layer 160, and the like.

The base layer 110 is a support layer for forming the lower/upper electrode layers 130 and 150 and the interlayer insulating layer 140, and may be in the form of a film. The base layer 110 may use a polymer material applicable to a flexible display, for example, cyclic olefin polymer (COP), polyethylene terephthalate (PET), polyacrylate (PAR), polyetherimide (PEI) , polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polyallylate, polyimide (PI), cellulose acetate propionate (CAP), polyethersulfone (PES), cellulose triacetate (TAC) ), polycarbonate (PC), cyclic olefin copolymer (COC), and polymethyl methacrylate (PMMA). Among these materials, since polyimide exhibits the most stable folding characteristics, it may be preferable to use polyimide as the base layer 110 in the present invention.

The digitizer adhesive layer 120 may be selectively included according to the type of FCCL (Flexible Copper Clad Laminate) used.

FCCL is a laminated form of copper foil as a conductor and polyimide as an insulator. There are single side FCCL (Single Side FCCL) where the copper foil exists on only one side and double side FCCL (Double Side FCCL) that exists on both sides. , a single-sided FCCL can be used in the present invention.

Single-sided FCCL consists of a three-layer laminating FCCL with an adhesive layer between the polyimide film and copper foil, a two-layer casting FCCL that melts and attaches polyimide resin to the copper foil, and a copper layer deposited on the polyimide film by sputtering. It can take many forms, such as layer sputtering FCCL. Here, the 3-layer FCCL and the 2-layer casting FCCL are formed with copper foil (thickness is usually 12 to 18 μm) manufactured by electroplating or rolling, and the 2-layer sputtering FCCL is formed by depositing copper with plasma and then reducing the thickness by electrolytic copper plating. As a result, a copper layer can be grown with a free thickness on the polyimide film, for example, a thin copper foil of 1 to 12 μm can be formed.

In this way, since the FCCL has a form in which an adhesive layer exists and a form in which an adhesive layer does not exist, the present invention may selectively include the digitizer adhesive layer 120 according to the FCCL used.

In the case of including the digitizer adhesive layer 120, the digitizer adhesive layer 120 may use an insulating adhesive. The insulating adhesive may include a thermosetting resin such as an epoxy resin, and may also include a curing agent, a binder, a flame retardant, and the like. there is.

The digitizer adhesive layer 120 may have a thickness of 5 to 50 μm. If the thickness is less than 5 μm, the thickness may not be sufficient to form the circuit pattern, that is, the lower electrode layer 130, and if the thickness exceeds 50 μm, flexibility may be deteriorated.

The lower electrode layer 130 forms, for example, a transmission-side electrode layer, and may be formed of a conductive metal as a circuit pattern. Conductive metals include, for example, 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 these may be used, preferably copper or a copper alloy.

The interlayer insulating layer 140 buries and protects the lower electrode layer 130, and is an organic insulating material such as an epoxy-based resin, an acrylic-based resin, a siloxane-based resin, or a polyimide-based resin, or an inorganic insulating material such as silicon oxide or silicon nitride. It can be composed of materials, etc.

It is preferable to use an organic insulating material for the interlayer insulating layer 140 to increase flexibility, and may have a thickness of 15 to 20 μm.

The upper electrode layer 150 is formed on the interlayer insulating layer 140 to form a receiving electrode, for example, and may be formed of a conductive metal as a circuit pattern. The conductive metal is silver (Ag), gold (Au), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), chromium (Cr), titanium ( Ti), tungsten (W), niobium (Nb), tantalum (Ta), vanadium (V), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), tin ( Sn), molybdenum (Mo), calcium (Ca), or an alloy containing at least two of them, preferably copper or a copper alloy.

The passivation layer 160 buries and protects the upper electrode layer 150, and is an organic insulating material such as an epoxy-based resin, an acrylic-based resin, a siloxane-based resin, or a polyimide-based resin, or an inorganic insulating material such as silicon oxide or silicon nitride. can be configured with

The passivation layer 160 is preferably formed of an organic insulating material in order to increase flexibility, and may have a thickness of 1.5 to 20 μm.

In one embodiment, each of the interlayer insulating layer 140 and the passivation layer 160 may include an inorganic insulating material and may have a thickness of about 100 nm to about 500 nm.

The integrated shielding layer 200 may be integrally formed with the digitizer 100 on the rear surface of the digitizer 100 .

The integrated shielding layer 200 is titanium (Ti), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), barium ( Ba) or a conductive metal containing two or more types of alloys thereof may be deposited, for example, a metal deposition layer may be formed through a sputtering process to function as an electromagnetic wave shielding layer.

The integrated shielding layer 200 may use silver (Ag), which has excellent electromagnetic wave shielding performance, but since silver (Ag) is expensive, manufacturing cost may increase. Accordingly, in the present invention, it is possible to form a metal deposition layer capable of exhibiting equivalent or better electromagnetic wave shielding performance without using an expensive silver (Ag) component.

The integrated shielding layer 200 uses one or more conductive metals selected from, for example, copper (Cu), nickel (Ni), titanium (Ti), barium (Ba), and zinc (Zn) as a target material, A sputtering process may be performed by selectively injecting oxygen (O ₂ ) as a reactive gas and argon (Ar) as a non-reactive gas into the chamber. The sputtering process is a method of forming a thin film using a phenomenon that target atoms emit when particles having high energy collide with a target and transmit energy, and a voltage is applied between the base layer 110, which is a deposition target, and the target. When applied, argon ions collide with the target to separate the target material from the target, and the released target material (including ionic state) can be deposited on the substrate layer 110 while selectively combining with oxygen ions, which are reactive gases. In the present invention, the method of the sputtering process is not particularly limited, and a known process may be employed and performed according to the desired constituent material and thickness of the integrated shielding layer 200 .

The integrated shielding layer 200 may be, for example, a thin film deposition layer of CuNiO, BaTiO, or NiZn.

The CuNiO deposited layer may contain 30 to 35 parts by weight of copper, preferably 32.5 parts by weight, 25 to 30 parts by weight of nickel, preferably 27.5 parts by weight, and 23 to 27 parts by weight of oxygen, preferably 25 parts by weight. can

The BaTiO deposited layer may contain 20 to 25 parts by weight of barium, preferably 22.5 parts by weight, 10 to 15 parts by weight of titanium, preferably 13 parts by weight, and 43 to 47 parts by weight of oxygen, preferably 45 parts by weight. can

The NiZn deposition layer may include 10 to 30 parts by weight of nickel, preferably 30 parts by weight, and 50 to 70 parts by weight of zinc, preferably 70 parts by weight. In the NiZn deposited layer, the shielding rate increases as the zinc content increases. However, if the zinc content exceeds 70 parts by weight, the NiZn composition phase becomes imbalanced and shielding performance may be lost.

Among the deposited films of CuNiO, BaTiO, and NiZn exemplified above, since the CuNiO deposited film has the best shielding performance, it may be preferable to use the CuNiO deposited film as the integral shielding layer 200 .

The integral shielding layer 200 may be configured to have a thickness of several hundred nm, for example, to a thickness of 400 to 800 nm in a band of 100 MHz to 1 GHz used for wired and wireless communication. If the thickness is less than 400 nm, shielding performance may deteriorate, and if the thickness exceeds 800 nm, stress may increase in the folding portion and cracks may occur in the folding portion.

When the integrated shielding layer 200 is formed through a sputtering process, the film density can be higher than that of a spray method or a powder method having a film density of 3 to 4 g/cm 3 . For example, in the case of deposited films of CuNiO, BaTiO, or NiZn, a film density of 6 to 7 g/cm 3 , preferably 6.07 to 6.62 g/cm 3 , can be maintained. Therefore, the shielding rate can be increased.

As shown in FIG. 2 , the integrated shielding layer 200 may be entirely formed under the digitizer 100 . In this case, the digitizer 100 on which the integrated shielding layer 200 is formed may have an inner/outer strain (ε _max ) of 0.1 to 1%. Here, the inner/outer strain (ε _max ) represents the maximum strain of the inner or outer surface, and can be defined by Equation 1 below.

[Equation 1]

ε _max = ±(t/2)/p = ±t/2(Rt/2)

Here, t is the sample thickness (sensor layer + shielding layer), p is the distance to the neutral plane, and R is the radius of curvature.

Table 1 below shows the inner/outer strain (ε _max ) of the digitizer combined with the integral shielding layer according to the present invention (Examples 1 and 2) and the digitizer combined with the conventional attachable shielding layer (Comparative Examples 1 and 2) is shown at a radius of curvature of 5 mm and 3 mm.

Bending radius (mm) Overall thickness (μm) Inner/outer strain (%) presence or absence of cracks 5 Example 1 50.6 0.5 doesn't exist Comparative Example 1 550 5.76 generation 3 Example 2 50.6 0.85 doesn't exist Comparative Example 2 550 9.91 generation

As shown in Table 1 above, the digitizer combined with the integrated shielding layer according to the present invention (Examples 1 and 2) compared to the digitizer combined with the conventional attachable shielding layer (Comparative Examples 1 and 2), the inner/outer It can be confirmed that cracks do not occur while the strain (ε _max ) is significantly lowered, and furthermore, the inner/outer strain (ε _max ) of the digitizer (Examples 1 and 2) combined with the integral shielding layer according to the present invention is 1%. It can be seen that it is maintained below.

3 and 4 are cross-sectional views showing modified examples of the digitizer panel of the present invention.

As shown in FIGS. 3 and 4 , the integral shielding layer 200 formed on the folding portion (the region folded around the folding axis A in FIGS. 3 and 4 ) can improve folding by reducing the thickness of the folding portion. there is. In the integrated shielding layer 200, the thickness reduction region N of the folding portion may have a cross section of a quadrangular shape, a triangular shape, etc., as shown in FIGS. 3 and 4, or a curved surface (circle, ellipse, etc.) may be

In the present invention, a process of pre-treating the base layer 110 may be additionally performed. The pretreatment process may include, for example, a process of performing ion beam treatment on the substrate layer 110 . The ion beam treatment increases the surface area of the base layer 110 and increases the adhesion of CuNiO, BaTiO, NiZn, and the like to the base layer 110 . The ion beam pretreatment is, for example, by using a mixed gas of oxygen and argon to cause oxygen, which is an active gas, to be incident on the surface of the base layer 110 in a plasma state to form a chemical link on the surface of the base layer 110 to increase adhesion. can

An image display device according to the present invention may include the digitizer panel described above and a display panel coupled to the digitizer panel, and may have a structure in which, for example, a touch panel, a display panel, and a digitizer panel are laminated.

The digitizer panel of the present invention may be disposed below the display panel so as not to be visually recognized by the user. In this case, the digitizer panel may be disposed below the display panel, that is, between the display panel and the rear cover.

The display panel may include a pixel electrode, a pixel defining layer, a display layer, a counter electrode, an encapsulation layer, and the like on a display substrate.

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

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

A counter electrode may be disposed on the pixel defining layer and the display layer. The counter electrode may serve as, for example, a common electrode or a cathode of an image display device. An encapsulation layer for protecting the display panel may be stacked on the opposite electrode.

The touch panel may be stacked on the display panel and disposed toward the outermost window substrate. The touch panel may detect a user's touch input through the surface of the window substrate. The touch panel may include sensing electrodes or sensing channels having a thickness smaller than that of the electrode layer included in the digitizer panel so as not to be visually recognized by a user. Sensing electrodes or sensing channels may be independently disposed in one single layer to generate capacitance by interacting with adjacent sensing electrodes or sensing channels. The touch panel may be coupled to the display panel through an adhesive layer.

A window panel may be coupled to the front of the touch panel. The window panel may include, for example, a hard coating film or thin glass, and a light blocking pattern may be formed around one surface of the window panel. By the light blocking pattern, the image display device may define a bezel part or a non-display area.

A polarization layer may be disposed between the window panel and the touch panel. The polarization layer may include a coated polarizer or polarizer. The polarization layer may be directly bonded to one surface of the window panel or attached via an adhesive layer. The touch panel may be combined with the polarization layer through an adhesive layer.

In this way, the image display device may be disposed in the order of a window panel, a polarization layer, a touch panel, a display panel, and a digitizer panel from a user's viewing side. In this case, since the sensing electrodes of the touch panel are disposed under the polarization layer, visibility of the sensing electrodes may be effectively prevented.

Meanwhile, the touch panel may be directly transferred onto a window panel or a polarization layer. In this case, the image display device may be disposed in the order of a window panel, a touch panel, and a polarization layer from the user's viewing side.

In the above, the present invention has been described as examples, which are for illustrating the present invention. Those skilled in the art will be able to change or modify these embodiments in other forms. However, since the scope of the present invention is determined by the claims below, such variations or modifications may be construed as being included in the scope of the present invention.

10,100: digitizer 11,110: substrate layer
12,120: digitizer adhesive layer 13,130: lower electrode layer
14,140: interlayer insulating layer 15,150: upper electrode layer
16,160: passivation layer 20: adhesion shielding layer
30: shielding adhesive layer 200: integral shielding layer

Claims (10)

A digitizer including a substrate layer and an electrode layer on an upper surface of the substrate layer; and
A digitizer panel having an integral shielding layer comprising a shielding layer deposited on the lower surface of the base layer. The method according to claim 1, wherein the base layer and the shielding layer
A digitizer panel having an integrated shielding layer including a folding portion. The method according to claim 1, wherein the shielding layer
A digitizer panel with an integral shielding layer having a reduced thickness in a folded portion. The method according to claim 1, wherein the shielding layer
A digitizer panel having an integral shielding layer comprising titanium (Ti), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), barium (Ba), or an alloy of two or more of these. The method according to claim 3, wherein the shielding layer
A digitizer panel having an integral shielding layer, further containing oxygen. The method according to claim 1, wherein the shielding layer
A digitizer panel having an integral shielding layer having a film density of 6 to 7 g/cm 3 . The method according to claim 1, wherein the shielding layer
A digitizer panel having an integral shielding layer having an inner/outer strain of 0.1 to 1%. The method according to claim 1, wherein the shielding layer
A digitizer panel with an integral shielding layer having a thickness of 400 to 800 nm. display panel; and
An image display device comprising a digitizer panel having the shielding layer according to claim 1 disposed below the display panel. The method of claim 9,
Including more rear cover,
The digitizer panel having the shielding layer is disposed between the display panel and the rear cover.

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