KR20190084630A - Force Sensor Laminate and Display Device Including the Same - Google Patents

Abstract

Provided are a laminate for a pressure sensor which is suitable using in a display device by being integrated with a polarizing plate and a refractive index adjusting layer, and a display device including the same. The laminate for a pressure sensor comprises: a polarizing plate; an adhesive layer; a separation layer; a protective layer; a refractive index adjusting layer; and an electrode pattern.

Description

[0001] The present invention relates to a pressure sensor laminate and a display device including the laminate.

The present invention relates to a laminate for a pressure sensor and a display device including the laminate, and more particularly to a laminate for a pressure sensor suitable for use in a display device integrated with a polarizing plate and a refractive index controlling layer and a display device including the same will be.

Recently, a touch input method in which a user directly touches a screen using a finger and inputs the touch input method is widely used. The touch input method can be combined with a display screen without a separate input device such as a keyboard or a mouse, and a user can directly touch and input a specific position of the display screen, thereby providing an intuitive and convenient user interface.

The structure of a capacitive touch sensor is widely used as a touch input method. The capacitive touch sensor includes a first touch sensing electrode sensing or sensing a capacitance change between a touch sensing electrode and a finger according to a touch input, And the position of the touch input is calculated by sensing the capacitance change between the second touch sensing electrodes.

However, as a function of an electronic device using a touch sensor as an input means, such as a smart phone, becomes diversified and complicated, a method capable of sensing a wider variety of touch inputs is required. Accordingly, A three-dimensional input method capable of additionally recognizing the direction of the pressing force, that is, the z-axis information, in addition to the information has been developed.

For example, in Korean Patent No. 10-1652029, a first electrode and a second electrode located on an insulating layer; And a pressure detecting module including an elastic foam. Korean Patent Laid-Open No. 10-2017-0121904 discloses a smart phone having a thin film transistor and flexibility. An organic light emitting device connected to the thin film transistor on the substrate; And a back plate having a pressure sensor configured to support the substrate under the substrate and measure the intensity of a touch input.

Korean Patent No. 10-1652029 Korean Patent Publication No. 10-2017-0121904

The present invention has been accomplished on the basis of the technical background described above, and it is an object of the present invention to provide a pressure sensor capable of sensing a three-dimensional input by additionally providing a pressure sensor in addition to a display device capable of sensing a conventional two- And a display device including the same.

Another object of the present invention is to achieve a manufacturing process simplification and thinning of a display device capable of sensing a three-dimensional input.

According to an aspect of the present invention, there is provided a polarizing plate comprising: a polarizing plate; An adhesive layer on the polarizing plate; A separating layer on the adhesive layer; A protective layer on top of the separation layer; A refractive index control layer on the protective layer; And a pressure sensing electrode pattern on the refractive index control layer.

Here, the refractive index control layer may include a SiON layer.

The refractive index control layer may have a laminated structure of two or more layers.

The pressure-sensitive electrode pattern may be formed to have a pattern that is denser at the edge than at the center.

According to another aspect of the present invention, A BLU coupled to the top of the frame; A counter electrode for pressure sensing located on the BLU; A pressure sensor laminated body coupled to the pressure sensing opposite electrode with an air gap or an OCA layer interposed therebetween; And a display layer coupled to an upper portion of the pressure sensor laminate.

In the pressure sensor stack, the polarizing plate may be coupled in a direction facing the display layer.

The display layer may be an LCD layer or an OLED layer.

According to the present invention, a pressure sensor laminate for a pressure sensor including a refractive index control layer can be formed on a polarizing plate by a transfer method, so that the pressure sensor can be easily added to a display device without impairing visibility.

Further, by forming the laminate for a pressure sensor integrally with the polarizer in this manner, the step of bonding with the polarizer can be omitted, and the polarizer can be used instead of the substrate of the pressure sensor laminate.

1 is a plan view schematically showing a laminate for a pressure sensor according to an embodiment of the present invention.
2 is a cross-sectional view taken along line II-II 'of FIG.
3 is a cross-sectional view schematically showing a display device including a laminate for a pressure sensor according to an embodiment of the present invention.
4A to 4G are process sectional views of a method of manufacturing a pressure sensor laminate according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail. In the following description of the present invention, reference will be made to the accompanying drawings, which are included to provide a further understanding of the invention, and are not intended to limit the invention. Also, for ease of explanation, some of the elements may be exaggerated in the drawings, or may be omitted or omitted.

The present invention provides a laminate for a pressure sensor which is formed on a polarizing plate by a transfer method and can be easily added to a display device and includes a refractive index control layer to improve visibility.

FIG. 1 is a plan view schematically showing a laminate for a pressure sensor according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II 'of FIG.

1 and 2, a pressure sensor laminate 10 according to an embodiment of the present invention includes a polarizer 110, an adhesive layer 120 on a polarizer 110, A protective layer 140 formed on the separation layer 130, a refractive index control layer 150 formed on the protective layer 140, and a pressure sensitive electrode pattern 140 formed on the refractive index control layer 150 And a passivation layer 170 covering the electrode pattern 160 for pressure sensing.

In one embodiment of the present invention, the polarizing plate 110 serves as a base for the pressure sensor laminate 10 and a known one used in a display device can be used.

Concretely, PVA (polyvinyl alcohol), TAC (triacetyl cellulose) or COP (cycloolefin polymer) series films can be used, but the present invention is not limited thereto.

The pressure sensor laminate 10 according to an embodiment of the present invention is formed by using a transfer method and the pressure sensitive adhesive layer 120 is formed on the pressure sensor components 130 to 130 formed on a separate carrier substrate 170) for bonding with the polarizing plate (110).

The adhesive layer 120 may be made of a polymer material such as OCA (Optically Clear Adhesive).

When OCA is used as the adhesive layer 120, the elastic modulus of the OCA may be 0 to 5 MPa and the thickness may be 5 to 150 mu m.

The separation layer 130 is a layer formed for peeling from the carrier substrate in the manufacturing process of the pressure sensor laminate 10 according to an embodiment of the present invention. Therefore, the separation layer 130 can be separated from the carrier substrate by a physical force.

A protective layer 140 is formed on the isolation layer 130 as a layer for protecting the isolation layer 130.

In an embodiment of the present invention, the separation layer 130 or the protection layer 140, or the separation layer 130 and the protection layer 140 may all be formed of an organic layer to provide a flexible pressure sensor.

As the material of the organic layer, a polymer material may be used. The polymer material may be, for example, polyacrylate, polymethacrylate (for example, PMMA), polyimide, polyamide, polyvinyl alcohol, polyamic acid polyamide resin, polyimide resin, polyimide resin, polymamic acid, polyolefin (e.g., PE, PP), polystyrene, polynorbornene, phenylmaleimide copolymer, polyazobenzene, A polymer such as polyphenylenephthalamide, polyester (e.g., PET, PBT), polyarylate, cinnamate polymer, coumarin polymer, phthalimidine polymer, A chalcone-based polymer, and an aromatic acetylene-based polymer.

In the pressure sensor laminate 10 according to an embodiment of the present invention, the pressure sensing electrode pattern may be integrated with the polarizing plate so that the pressure sensing electrode pattern may be coupled at the step of bonding the polarizing plate in the display device. At this time, there is a possibility that the pressure-sensing electrode pattern 160 is viewed by the user depending on the direction and / or the engagement position of the pressure-sensor stack 10.

In order to prevent this, in the layered product 10 for a pressure sensor according to an embodiment of the present invention, a refractive index control layer 150 is formed on the protective layer 140 before forming the pressure sensing electrode pattern 160 .

The material for forming the refractive index control layer 150 may be any material known in the art without any particular limitation. For example, SiON may be used. In addition, as the inorganic material, for example, zirconium oxide, zinc oxide, silicon oxide, cerium oxide, indium oxide, titanium oxide and the like can be used. Examples of the organic material include an acrylic compound and a silicon compound have. These may be used alone or in combination of two or more.

The refractive index control layer 150 may be formed as a single layer having one refractive index, or may be formed by stacking at least two layers having different refractive indexes.

When the refractive index control layer 150 is formed of a plurality of layers, the protective layer 140 may be laminated on the protective layer 140 in the order of high refractive index layer / low refractive index layer. In this case, The difference can be further reduced and the visibility can be improved.

The refractive index of the refractive index control layer 150 is not particularly limited but may be, for example, 1.45 to 2.5. When the refractive index control layer 150 is formed of a high refractive index layer / a low refractive index layer, The refraction layer may be from 1.45 to 1.95.

The thickness of the refractive index control layer 150 is not particularly limited. For example, in the case of an inorganic thin film, the thickness of the refractive index control layer 150 may be 10 to 1000 ANGSTROM, preferably 50 to 200 ANGSTROM, Lt; / RTI >

The method of forming the refractive index control layer 150 is not particularly limited. For example, gravure method, vacuum deposition method, sputtering method, ion plating method, or the like can be used. .

The pressure sensing electrode pattern 160 formed on the refractive index control layer 150 may be formed of a transparent conductive material and may be selected from a metal, a metal nanowire, a metal oxide, a carbon nanotube, a graphene, a conductive polymer, May be formed of one or more materials.

Here, the metal may be any one of gold, silver, copper, molybdenum, aluminum, palladium, neodymium, platinum, zinc, tin, titanium and alloys thereof.

The metal nanowires may be silver nanowires, copper nanowires, zirconium nanowires, or gold nanowires.

The metal oxide is selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO), florinthine oxide (ZnO).

The pressure sensing electrode pattern 160 may be formed of a carbon material including carbon nanotube (CNT) or graphene.

The conductive polymer includes polypyrrole, polythiophene, polyacetylene, PEDOT, and polyaniline. The conductive ink is a mixture of a metal powder and a curable polymer binder .

In addition, the pressure-sensing electrode pattern 160 may have a laminated structure of two or more conductive layers in order to reduce electrical resistance.

In one embodiment, the pressure-sensing electrode pattern 160 may be formed of one layer of ITO, AgNW (silver nano wire), or metal mesh. In the case of forming two or more layers, the first electrode layer may be formed of a transparent metal Oxide, and a second electrode layer may be formed on the ITO electrode layer using metal, AgNW, or the like in order to further lower the electrical resistance.

The pressure-sensing electrode pattern 160 may be formed in various forms known in the art, and may have a shape in which the pattern is formed more densely at the edge portion than in the central portion of the pressure sensor, as shown in FIG. 1 .

The reason why the electrode pattern 160 for pressure sensing is formed in this manner is that the displacement of the pressure sensing electrode with respect to the touch input of the user having the same force varies depending on the position of the pressure sensor. That is, at the edge portion of the pressure sensor, the displacement of the pressure sensing electrode is less than that at the center portion even if the touch input is performed with the same force. In order to compensate the displacement, the edge portion pattern is formed more densely than the center portion.

Now, a display device according to an embodiment of the present invention including the laminate 10 for a pressure sensor as described above will be described.

3 is a cross-sectional view schematically showing a display device including a laminate 10 for a pressure sensor according to an embodiment of the present invention.

3, a display device according to an embodiment of the present invention includes a BLU 30 on a frame 40, and an air gap or an OCA layer for pressure and distance measurement on the BLU 30, The laminate 10 for a pressure sensor described with reference to Figs. 1 and 2 is attached with the base 20 interposed therebetween. A display layer 50, a touch sensor 60, a polarizing plate 70, and a cover glass 80 are stacked in this order on the laminate 10 for a pressure sensor.

The laminate 10 for a pressure sensor can be attached in a direction in which the polarizing plate (FIG. 2: 110) faces the display layer 50. 2) 160 may be located above the BLU 30, which may cause the pressure sensing electrode pattern 160 to be visible to the user, In the laminate 10 for a pressure sensor according to an embodiment of the present invention, the difference in reflectance between the portion where the pressure-sensing electrode pattern 160 is formed and the portion where the pressure-sensing electrode pattern 160 is not formed is reduced through the refractive index control layer Visibility problems can be solved.

Further, although not shown in the drawings, a pressure sensing counter electrode may be formed between the air gap or the OCA layer 20 and the BLU 30. [

The display layer 50 may be, for example, an OLED layer or an LCD layer, but is not limited thereto.

The touch sensor 60 is a touch sensor capable of sensing a two-dimensional touch input, and may be, for example, a capacitive touch sensor, but is not limited thereto.

According to the display device including the laminate 10 for a pressure sensor according to an embodiment of the present invention, the step of bonding the polarizing plate to the polarizing plate can be omitted by forming the pressure-sensing electrode pattern integrally with the polarizing plate, Since the polarizing plate is used instead of the substrate of the laminate, the thinning of the display device can be achieved.

Now, a method of manufacturing a pressure sensor laminate according to an embodiment of the present invention will be described in detail.

In the pressure sensor laminate of the present invention, after the laminate structure is formed by carrying out the process using the carrier substrate, the carrier substrate can be separated and the polarizer can be attached.

4A to 4G are process sectional views of a method of manufacturing a pressure sensor laminate according to an embodiment of the present invention.

First, referring to FIG. 4A, after preparing the carrier substrate 100, a separation layer 130 is formed by applying a composition for forming a separation layer.

As the carrier substrate 100, a glass substrate is preferably used, but not limited thereto. However, it is preferable that the material has heat resistance so as not to be deformed even at high temperature, that is, to maintain the flatness so as to withstand the temperature in the process of forming the pressure sensing sensor thereafter.

As the material of the separation layer 130, a polymer organic film as described above can be used.

As a method of applying the composition for forming a separation layer, a known coating method may be used. For example, spin coating, die coating, spray coating, roll coating, screen coating, slit coating, dip coating, gravure coating and the like can be mentioned. Or an inkjet method may be used.

The composition for forming the separation layer is coated and cured to form the separation layer 130. In this case, the curing process may be performed using heat curing or UV curing alone, or a combination of thermal curing and UV curing. When the thermosetting is used, it can be heated by an oven, a hot plate, etc. The heating temperature and time may vary depending on the composition, but for example, the heat treatment may be performed at 80 to 250 ° C for 10 to 120 minutes.

Next, as shown in FIG. 4B, a protective layer 140 is formed by applying a composition for forming a protective layer on the formed separation layer 130.

The material of the composition for forming the protective layer, the coating method and the curing step are as described above for the separation layer.

4C, a refractive index-adjusting layer 150 is formed on the protective layer 140. The refractive index-

The refractive index control layer 150 can be formed by, for example, depositing SiON.

Next, as shown in FIG. 4D, a transparent conductive film is formed on the refractive index control layer 150 and patterned to form the electrode pattern 160 for pressure sensing. The patterning of the transparent conductive film can be performed through a photolithography process using a photosensitive resist.

The photosensitive resist may be a negative type photosensitive resist or a positive type photosensitive resist.

4E, a passivation layer 170 is formed on the electrode pattern 160 for pressure sensing.

Next, as shown in FIG. 4F, the separation layer 130 in which the laminated structure is formed is separated from the carrier substrate 100 used for carrying out the manufacturing process of the laminated structure. The process of separating the carrier substrate 100 from the separation layer 130 is performed at room temperature and can be performed by a physical separation method in which the carrier substrate 100 as a glass substrate is separated from the separation layer 130 have.

The method of peeling may be a lift-off method or a peel-off method, but is not limited thereto.

In this case, the magnitude of the force applied at the time of peeling may vary depending on the peeling force of the separation layer, but it is preferably 1 N / 25 mm or less, more preferably 0.1 N / 25 mm or less. If the peeling force is more than 1 N / 25 mm, there is a possibility that the film touch sensor tears when peeling off from the carrier substrate, and excessive force is applied to the film touch sensor, have.

Next, as shown in FIG. 4G, the polarizing plate 110 is attached to the surface of the separation layer 130 from which the carrier substrate 100 is peeled, using an adhesive or an adhesive.

For example, the polarizing plate 110 may be adhered to the separation layer 130 using an adhesive such as OCA.

For example, the polarizing plate 110 can be adhered to the separation layer 130 using an adhesive. Since the adhesive that can be used is a photo-curable adhesive and does not require a separate drying step after photo-curing, . As the photocurable adhesive used in the present invention, the photocurable adhesive used in the field can be used without any particular limitation. For example, a composition comprising an epoxy compound or an acrylic monomer may be used.

In the photocuring of the adhesive layer, an electron beam, a proton beam, a neutron beam, etc. may be used in addition to an electromagnetic wave such as a deep ultraviolet ray, ultraviolet ray, near ultraviolet ray, infrared ray, X- It is advantageous to cure by ultraviolet irradiation from the availability of the irradiation apparatus, the price, and the like.

As a light source for ultraviolet irradiation, a high-pressure mercury lamp, an electrodeless lamp, an ultra-high pressure mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a chemical lamp or a black light may be used.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. However, it should be understood that the present invention is not limited to the above-described embodiment, and that the present invention can be implemented in a modified form without departing from the essential characteristics of the present invention. The above-described embodiments of the present invention can be applied independently or in combination of some or all of the features.

Therefore, the scope of the present invention is defined by the appended claims rather than the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

10: Laminate for pressure sensor 20: Air gap or OCA layer
30: backlight unit 40: frame
50: display layer 60: touch sensor
70: polarizer 80: cover glass
110: polarizer 120: adhesive layer
130: isolation layer 140: protective layer
150: refractive index control layer 160: pressure-sensitive electrode pattern
170: Passivation layer

Claims (7)

Polarizer;
An adhesive layer on the polarizing plate;
A separating layer on the adhesive layer;
A protective layer on top of the separation layer;
A refractive index control layer on the protective layer; And
And a pressure-sensitive electrode pattern on the refractive index control layer. The method according to claim 1,
Wherein the refractive index control layer comprises a SiON layer. The method according to claim 1,
Wherein the refractive index control layer has a laminated structure of two or more layers. The method according to claim 1,
Wherein the pressure sensing electrode pattern is formed to have a pattern that is denser at the edge than at the center. frame;
A BLU coupled to the top of the frame;
A counter electrode for pressure sensing located on the BLU;
The pressure sensor laminate according to any one of claims 1 to 3, further comprising an air gap or an OCA layer sandwiched between the opposed electrodes for pressure sensing. And
And a display layer coupled to the upper portion of the pressure sensor laminate. 6. The method of claim 5,
Wherein the pressure sensor laminate has the polarizer coupled to the display layer in a direction opposite to the display layer. 6. The method of claim 5,
Wherein the display layer is an LCD layer or an OLED layer.

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