Display device, transparent pressure sensor and method of manufacturing thereof

Abstract

The application provides a transparent pressure sensor, which comprises an insulating substrate, a strain pattern, a hollow strain body, a functional circuit layer and a transparent adhesive layer. The insulating substrate comprises a plurality of pressure sensing areas and non-pressure sensing areas other than the pressure sensing areas, a plurality of openings are arranged through the pressure sensing areas, the strain patterns are arranged on opposite sides of the insulating substrate, part of the strain patterns are filled into the openings to form the hollow strain body, and the hollow strain body is connected between the two strain patterns. The functional circuit layer is arranged on the strain pattern, and the functional circuit layer is electrically connected with the strain pattern. The transparent adhesive layer covers the functional circuit layer and the strain pattern, and part of the transparent adhesive layer is filled into the hollow strain body. The transparent pressure sensor provided by the application has both light transmission and sensitivity. In addition, the application also provides a manufacturing method of the transparent pressure sensor and a display device.

Description

TECHNICAL FIELD

[0001] The present application relates to a display device, a transparent pressure sensor and a manufacturing method thereof. BACKGROUND

[0002] In the field of human-computer interaction and smart home, the pressure sensor applied in the touch screen not only requires high sensitivity, but also has a very high requirement on transparency. In the prior art, the conductor material of the high-sensitivity pressure sensor has poor light transmission, which makes it difficult to have both light transmission and sensitivity. SUMMARY

[0003] In view of the above, it is necessary to provide a transparent pressure sensor to solve the above problems.

[0004] In addition, it is also necessary to provide a manufacturing method of a transparent pressure sensor.

[0005] In addition, it is also necessary to provide a display device.

[0006] A manufacturing method of a transparent pressure sensor comprises the steps of: providing an insulating substrate, the insulating substrate having a plurality of pressure sensing areas and non-pressure sensing areas other than the pressure sensing areas, and the pressure sensing areas being provided with a plurality of openings. Strain layers are provided on opposite sides of the insulating substrate, and part of the strain layers are filled into the openings to form hollow strain bodies, and each of the hollow strain bodies is connected between two oppositely arranged strain layers. An electroplating layer is provided on the strain layer corresponding to the non-pressure sensing area. Part of the strain layers in the pressure sensing areas are removed to obtain a strain pattern, and the strain pattern is electrically connected to a plurality of hollow strain bodies. The electroplating layer is etched to obtain a functional circuit layer, and the functional circuit layer is electrically connected to the strain pattern. A transparent adhesive layer is provided on the functional circuit layer and the strain pattern, and the transparent adhesive layer is filled into the hollow strain bodies.

[0007] Further, the step of "providing an electroplating layer on the strain layer corresponding to the non-pressure sensing area" comprises: providing a first dry film layer on the insulating substrate, exposing and developing the first dry film layer to form a first dry film photosensitive pattern, the strain layer corresponding to the non-pressure sensing area being exposed to the first dry film photosensitive pattern, providing the electroplating layer, and removing the first dry film photosensitive pattern.

[0008] Further, the step of "removing part of the strain layer in the pressure sensing area to obtain a strain pattern" comprises: disposing a second dry film layer on the electroplated layer and the strain layer. The second dry film layer is exposed and developed to form a second dry film photoresist pattern, and part of the strain layer corresponding to the pressure sensing area is exposed to the second dry film photoresist pattern. The part of the strain layer exposed to the second dry film photoresist pattern is removed to obtain the strain pattern, and the second dry film photoresist pattern is removed.

[0009] Further, part of the electroplated layer corresponding to the non-pressure sensing area is exposed to the second dry film photoresist pattern, and the manufacturing method further comprises: etching part of the electroplated layer exposed to the second dry film photoresist pattern to obtain the functional circuit layer.

[0010] A transparent pressure sensor comprises an insulating substrate, a strain pattern, a hollow strain body, a functional circuit layer, and a transparent adhesive layer. The insulating substrate comprises a plurality of pressure sensing areas and non-pressure sensing areas other than the pressure sensing areas, a plurality of openings are disposed through the pressure sensing areas, the strain pattern is disposed on opposite sides of the insulating substrate, part of the strain pattern fills into the openings to form the hollow strain body, and the hollow strain body is connected between two strain patterns. The functional circuit layer is disposed on the strain pattern, and the functional circuit layer is electrically connected to the strain pattern. The transparent adhesive layer covers the functional circuit layer and the strain pattern, and part of the transparent adhesive layer fills into the hollow strain body.

[0011] Further, the functional circuit layer comprises a resistance measuring circuit and a connecting circuit, the connecting circuit is electrically connected to the resistance measuring circuit and the strain pattern, and the resistance measuring circuit is used to measure the resistance value change amount of the strain pattern and the hollow strain body electrically connected to the strain pattern.

[0012] Further, the transparent pressure sensor further comprises a pressure measuring chip, the pressure measuring chip is electrically connected to the resistance measuring circuit, the pressure measuring chip pre-stores a pressure-resistance relationship, and the pressure measuring chip is used to obtain a pressure value according to the resistance value change amount and the pressure-resistance relationship.

[0013] Further, the material of the hollow strain body and the strain pattern comprises metal, metal oxide, and conductive non-metal, the metal comprises at least one of chromium, gold, and nickel, the metal oxide comprises at least one of chromium oxide and nickel oxide, and the conductive non-metal comprises at least one of nano-carbon and graphene.

[0014] Further, the transparent adhesive layer comprises at least one of optical adhesive, transparent cover layer, and ionic liquid.

[0015] A display device comprising a touch screen, the display device further comprising the transparent pressure sensor as described above, the pressure sensor being arranged on one side of the touch screen.

[0016] The transparent pressure sensor provided by the present application increases the total amount of strain bodies in the insulating substrate per unit volume by arranging the hollow strain bodies in the opening on the insulating substrate and connecting the strain patterns to the opposite sides of the hollow strain bodies, so that the pressure acting on the unit volume can produce greater resistance changes, thereby ensuring the high sensitivity of the transparent pressure sensor, reducing the width of the strain patterns and improving the transparency of the transparent pressure sensor. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 A schematic diagram of the insulating substrate provided by an embodiment of the present application.

[0018] Figure 2 A schematic diagram of the insulating substrate provided by an embodiment of the present application. Figure 1 A schematic diagram of the insulating substrate provided by an embodiment of the present application.

[0019] Figure 3 A schematic diagram of the insulating substrate provided by an embodiment of the present application. Figure 2 A schematic diagram of the insulating substrate provided by an embodiment of the present application.

[0020] Figure 4 A schematic diagram of the insulating substrate provided by an embodiment of the present application. Figure 3 A schematic diagram of the insulating substrate provided by an embodiment of the present application.

[0021] Figure 5 A schematic diagram of the insulating substrate provided by an embodiment of the present application. Figure 4 A schematic diagram of the insulating substrate provided by an embodiment of the present application.

[0022] Figure 6 A schematic diagram of the insulating substrate provided by an embodiment of the present application. Figure 3 A schematic diagram of the insulating substrate provided by an embodiment of the present application.

[0023] Figure 7 A schematic diagram of the insulating substrate provided by an embodiment of the present application. Figure 6 A schematic diagram of the insulating substrate provided by an embodiment of the present application.

[0024] Figure 8 A schematic diagram of the insulating substrate provided by an embodiment of the present application. Figure 7 A schematic diagram of the insulating substrate provided by an embodiment of the present application.

[0025] Figure 9 A schematic diagram of the insulating substrate provided by an embodiment of the present application. Figure 8 A schematic diagram of the insulating substrate provided by an embodiment of the present application.

[0026] Figure 10 A schematic diagram of the insulating substrate provided by an embodiment of the present application. Figure 9 A schematic diagram of the insulating substrate provided by an embodiment of the present application.

[0027] Figure 11 A schematic diagram of the insulating substrate provided by an embodiment of the present application.Figure 8 schematic diagram of the second dry film pattern provided on the electroplated layer.

[0028] Figure 12 to remove Figure 11 schematic diagram of the partial strain layer.

[0029] Figure 13 to remove Figure 12 schematic diagram of the second dry film pattern.

[0030] Figure 14 schematic diagram of the transparent pressure sensor provided in an embodiment of the present application.

[0031] Figure 15 schematic diagram of the transparent pressure sensor. Figure 14 schematic diagram of the transparent pressure sensor.

[0032] Figure 16 schematic diagram of the transparent pressure sensor. Figure 14 schematic diagram of the transparent pressure sensor.

[0033] Figure 17 schematic diagram of the transparent pressure sensor. Figure 14 schematic diagram of the transparent pressure sensor.

[0034] Figure 18 schematic diagram of the display device provided in an embodiment of the present application.

[0035] Main element symbol explanation

[0036] transparent pressure sensor 100

[0037] insulating substrate 10

[0038] pressure sensing area 11

[0039] non-pressure sensing area 12

[0040] aperture 13

[0041] through hole 14

[0042] strain layer 20

[0043] strain pattern 21

[0044] connecting body 211

[0045] hollow strain body 30

[0046] electroplated layer 40

[0047] conductive body 41

[0048] first dry film layer 42

[0049] First dry film photosensitive pattern 43

[0050] Second dry film layer 45

[0051] Second dry film pattern 46

[0052] Functional circuit layer 47

[0053] Resistance measurement circuit 471

[0054] Connection circuit 472

[0055] Pressure measurement chip 473

[0056] Transparent adhesive layer 50

[0057] Mobile phone display screen 300

[0058] Display panel 301

[0059] Thickness direction H

[0060] Thickness D1, D2

[0061] Aperture R

[0062] Pitch L

[0063] The following specific embodiments will further illustrate the present application in conjunction with the above figures. DETAILED DESCRIPTION

[0064] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments.

[0065] Referring to Figures 1 to 17 , the present application provides a manufacturing method of a transparent pressure sensor 100, comprising the steps of:

[0066] S1: Referring to Figure 1 , an insulating substrate 10 is provided, which comprises a plurality of pressure sensing areas 11 and non-pressure sensing areas 12 except the pressure sensing areas 11. Referring to Figure 2 , a plurality of openings 13 are provided through the pressure sensing areas 11, and a plurality of through holes 14 are provided through the non-pressure sensing areas 12.

[0067] In this embodiment, in step S1, the insulating substrate 10 is a flexible transparent substrate, and the material of the insulating substrate 10 includes one of polyethylene terephthalate, polyethylene naphthalate, polyamide and flexible glass. The thickness D1 of the insulating substrate 10 is 10 microns to 100 microns. The light transmittance of the insulating substrate 10 is greater than 85%, and the haze is less than 5%.

[0068] In the present embodiment, referring to Figure 2 , the insulating substrate 10 has a thickness direction H, a plurality of the openings 13 penetrate the insulating substrate 10 along the thickness direction H, the openings 13 are arranged in a matrix in the pressure sensing area 11, the aperture R of the opening 13 is 10 microns to 100 microns, and the spacing L between every two adjacent openings 13 is 1 micron to 20 microns. The through hole 14 penetrates the insulating substrate 10 along the thickness direction H.

[0069] S2: referring to Figure 3 , strain layers 20 are arranged on opposite sides of the insulating substrate 10, part of the strain layers 20 fill into the openings 13 to form hollow strain bodies 30, and each hollow strain body 30 is connected between two oppositely arranged strain layers 20.

[0070] In the present embodiment, in step S2, the strain layers 20 and the hollow strain bodies 30 include thin film metal, nanowire metal, oxide metal, graphene, and carbon nanotube. Specifically, the material of the thin film metal includes chromium, gold, and nickel, and the oxide metal includes chromium oxide and nickel oxide.

[0071] In the present embodiment, in step S2, the thickness D2 of the strain layer 20 is 0.05 microns to 0.5 microns. Preferably, the thickness D2 is less than 0.3 microns, so that the light transmittance of the strain layer 20 can be improved, and the material of the strain layer 20 can be selected to have a light transmittance greater than 50% or less than 50%. In other embodiments of the present application, the thickness D2 of the strain layer 20 can be adjusted according to the requirements of the conductive performance and the light transmittance.

[0072] S3: referring to Figures 4 to 8 , electroplating is performed on the strain layer 20 corresponding to the non-pressure sensing area 12 to form an electroplated layer 40, the electroplated layer 40 fills into the through hole 14 to form a conductive body 41, and the conductive body 41 electrically connects two corresponding electroplated layers 40.

[0073] In the present embodiment, step S3 includes:

[0074] S30: referring to Figure 4 , a first dry film layer 42 is arranged on the strain layer 20.

[0075] S31: referring to Figure 5 , the first dry film layer 42 is exposed and developed to form a first dry film photosensitive pattern 43 (see Figure 6 ), and the strain layer 20 corresponding to the non-pressure sensing area 12 is exposed on the first dry film photosensitive pattern 43.

[0076] S32: Please refer to Figure 7 , electroplating on the strain layer 20 exposed on the first dry film photo pattern 43 to form the electroplating layer 40.

[0077] S33: Please refer to Figure 8 , peeling off the first dry film photo pattern 43.

[0078] S4: Please refer to Figures 9 to 13 , removing the strain layer 20 corresponding to the pressure sensing area 11 to obtain a strain pattern 21, the strain pattern 21 electrically connecting a plurality of the hollow strain bodies 30, and etching the electroplating layer 40 to obtain a functional circuit layer 47, the functional circuit layer 47 electrically connecting the strain pattern 21, the resistance value of the hollow strain body 30 and the strain pattern 21 changing with the external pressure (for example, the force of the user's finger pressing on the pressure sensing area 11).

[0079] In this embodiment, step S4 includes:

[0080] S40: Please refer to Figure 9 , disposing a second dry film layer 45 on the electroplating layer 40 and the strain layer 20.

[0081] S41: Please refer to Figure 10 , exposing and developing the second dry film layer 45 to form a second dry film pattern 46 (Please refer to Figure 11 ), the strain layer 20 corresponding to the pressure sensing area 11 is exposed on the second dry film pattern 46, and part of the electroplating layer 40 is exposed on the second dry film pattern 46.

[0082] S42: Please refer to Figure 12 , removing the strain layer 20 exposed on the second dry film pattern 46 to obtain a strain pattern 21, and etching the electroplating layer 40 exposed on the second dry film pattern 46 to obtain a functional circuit layer 47.

[0083] S43: Please refer to Figure 13 , peeling off the second dry film pattern 46.

[0084] In this embodiment, please refer to Figure 16 , the strain pattern 21 includes a plurality of connecting bodies 211, the connecting body 211 connecting two adjacent hollow strain bodies 30, and all the hollow strain bodies 30 corresponding to the pressure sensing area 11 are connected in series through the connecting body 211. The line width of the connecting body 211 is 1-20 microns. In other embodiments of the present application, the line width of the connecting body 211 can be adjusted according to the requirements of conductivity and light transmittance.

[0085] In this embodiment, please refer toFigure 15 and Figure 17 The functional circuit layer 47 comprises a resistance measuring circuit 471 and a connecting circuit 472, the connecting circuit 472 electrically connecting the resistance measuring circuit 471 and the strain pattern 21, the resistance measuring circuit 471 being used for measuring the resistance change of the strain pattern 21 and the hollow strain body electrically connected with the strain pattern. The resistance measuring circuit 471 is a Wheatstone bridge, and the connecting circuit 472 is a connecting copper wire.

[0086] In the embodiment, please refer to Figure 15 The functional circuit layer 47 further comprises a pressure measuring chip 473, the pressure measuring chip 473 being electrically connected with the resistance measuring circuit 471, the pressure measuring chip 473 pre-storing a pressure-resistance relationship, and the pressure measuring chip 473 obtaining a pressure value according to the resistance change and the pressure-resistance relationship.

[0087] S5: A transparent adhesive layer 50 is arranged on the functional circuit layer 47 and the strain pattern 21, and the transparent adhesive layer 50 is filled into the hollow strain body 30.

[0088] In the embodiment, the transparent adhesive layer 50 comprises optical adhesive, transparent cover layer and ionic liquid.

[0089] Please refer to Figure 14 The application further provides a transparent pressure sensor 100, which comprises an insulating substrate 10, a strain pattern 21, a hollow strain body 30, a functional circuit layer 47 and a transparent adhesive layer 50. The insulating substrate 10 comprises a plurality of pressure sensing areas 11 and non-pressure sensing areas 12 except the pressure sensing areas 11, a plurality of openings 13 are arranged through the pressure sensing areas 11, and the hollow strain body 30 is arranged in the openings 13. The strain patterns 21 are arranged on opposite sides of the insulating substrate 10, and the hollow strain body 30 is connected between the two strain patterns 21. The functional circuit layer 47 is arranged on the strain pattern 21, and the functional circuit layer 47 is electrically connected with the strain pattern 21. The transparent adhesive layer 50 covers the functional circuit layer 47 and the strain pattern 21, and part of the transparent adhesive layer 50 is filled into the hollow strain body 30.

[0090] The transparent pressure sensor 100 provided by the present application increases the total amount of strain bodies (including the hollow strain body 30 and the strain pattern 21) in the unit volume of the insulating substrate 10 by setting the opening 13 on the insulating substrate 10, setting the hollow strain body 30 in the opening 13, and connecting the strain pattern 21 to opposite sides of the hollow strain body 30, so that the pressure acting on the unit volume can produce greater resistance changes, thereby ensuring high sensitivity of the transparent pressure sensor 100, and facilitating reduction of the width of the strain pattern 21 and improvement of the transparency of the transparent pressure sensor 100.

[0091] Please refer to Figure 18 The present application also provides a mobile phone display screen 300, which comprises a touch screen 301 and the transparent pressure sensor 100, the transparent pressure sensor 100 is arranged on one side of the touch screen 301, the touch screen 301 is used for displaying a graphic interface, and the transparent pressure sensor 100 area is used for controlling the graphic interface. In other embodiments of the present application, the transparent pressure sensor 100 can also be used for other touch screens 301, and the touch screen 301 can also be applied to display devices such as smart home appliances.

[0092] In addition, those skilled in the art can make other changes within the spirit of the present application, of course, these changes made according to the spirit of the present application should be included in the scope of protection claimed by the present application.

Claims

1. A method of manufacturing a transparent pressure sensor, characterized by, The method comprises the steps of: providing an insulating substrate, the insulating substrate having a plurality of pressure sensing areas and non-pressure sensing areas other than the pressure sensing areas, the pressure sensing areas being provided with a plurality of openings; providing strain layers on opposite sides of the insulating substrate, part of the strain layers being filled into the openings to form hollow strain bodies, each of the hollow strain bodies being connected between two oppositely arranged strain layers; providing a plating layer on the strain layers corresponding to the non-pressure sensing areas; removing part of the strain layers in the pressure sensing areas to obtain a strain pattern, the strain pattern being electrically connected to a plurality of the hollow strain bodies, the strain pattern being provided with openings, the insulating substrate being exposed at the openings, the openings on opposite sides of the insulating substrate being staggered, the strain pattern comprising a plurality of connecting bodies, the connecting bodies connecting two adjacent hollow strain bodies, and all the hollow strain bodies corresponding to the pressure sensing areas being connected in series through the connecting bodies; etching the plating layer to obtain a functional circuit layer, the functional circuit layer being electrically connected to the strain pattern; providing a transparent adhesive layer on the functional circuit layer and the strain pattern, and filling the transparent adhesive layer into the hollow strain bodies and the openings.

2. The production method according to claim 1, wherein The step of "providing a plating layer on the strain layers corresponding to the non-pressure sensing areas" comprises: providing a first dry film layer on the insulating substrate; exposing and developing the first dry film layer to form a first dry film photosensitive pattern, the strain layers corresponding to the non-pressure sensing areas being exposed to the first dry film photosensitive pattern; providing the plating layer; and removing the first dry film photosensitive pattern.

3. The production method according to claim 1, wherein The step of "removing part of the strain layers in the pressure sensing areas to obtain a strain pattern" comprises: providing a second dry film layer on the plating layer and the strain layers; exposing and developing the second dry film layer to form a second dry film photosensitive pattern, part of the strain layers corresponding to the pressure sensing areas being exposed to the second dry film photosensitive pattern; removing part of the strain layers exposed to the second dry film photosensitive pattern to obtain the strain pattern; and removing the second dry film photosensitive pattern.

4. The production method according to claim 3, wherein Part of the plating layer exposed to the second dry film photosensitive pattern, the method further comprises: etching part of the plating layer exposed to the second dry film photosensitive pattern to obtain the functional circuit layer.

5. A transparent pressure sensor, characterized by The method comprises an insulating substrate, a strain pattern, hollow strain bodies, a functional circuit layer, and a transparent adhesive layer, the insulating substrate comprising a plurality of pressure sensing areas and non-pressure sensing areas other than the pressure sensing areas, the pressure sensing areas being provided with a plurality of openings, the strain pattern being provided on opposite sides of the insulating substrate, part of the strain pattern being filled into the openings to form the hollow strain bodies, the hollow strain bodies being connected between two oppositely arranged strain patterns, the strain pattern being provided with openings, the insulating substrate being exposed at the openings, the openings on opposite sides of the insulating substrate being staggered, the strain pattern comprising a plurality of connecting bodies, the connecting bodies connecting two adjacent hollow strain bodies, and all the hollow strain bodies corresponding to the pressure sensing areas being connected in series through the connecting bodies. The functional circuit layer is arranged on the strain pattern, and the functional circuit layer is electrically connected to the strain pattern, The transparent adhesive layer covers the functional circuit layer and the strain pattern, and part of the transparent adhesive layer fills the hollow strain body and the opening.

6. The transparent pressure sensor of claim 5, wherein, The functional circuit layer comprises a resistance measuring circuit and a connecting circuit, the connecting circuit is electrically connected to the resistance measuring circuit and the strain pattern, and the resistance measuring circuit is used for measuring the resistance change of the strain pattern and the hollow strain body electrically connected to the strain pattern.

7. The transparent pressure sensor of claim 6, wherein, The transparent pressure sensor further comprises a pressure measuring chip, the pressure measuring chip is electrically connected to the resistance measuring circuit, the pressure measuring chip pre-stores a piezoresistive relationship, and the pressure measuring chip is used for obtaining a pressure value according to the resistance change and the piezoresistive relationship.

8. The transparent pressure sensor of claim 5, wherein, The material of the hollow strain body and the strain pattern comprises metal, metal oxide and conductive non-metal, the metal comprises at least one of chromium, gold and nickel, the metal oxide comprises at least one of chromium oxide and nickel oxide, and the conductive non-metal comprises at least one of nano-carbon and graphene.

9. The transparent pressure sensor of claim 5, wherein, The transparent adhesive layer comprises at least one of optical adhesive, transparent cover layer and ionic liquid.

10. A display device comprising a touch screen, characterized in that The display device further comprises the transparent pressure sensor according to any one of claims 5 to 9, and the pressure sensor is arranged on one side of the touch screen.

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