A kind of composite membrane touch sensing and preparation method thereof
Technical field
The present invention relates to a kind of touch sensings to belong to touch screen research field for handset touch panel etc..
Background technique
Touch screen (Touch panel) is also known as touch panel, is the induction type liquid of the input signals such as receivable contact
Crystal device, when contacting the graphic button on screen, the haptic feedback system on screen can be according to the journey of preprogramming
Formula drives various connection devices, is substituted for mechanical push button panel, and produces by liquid crystal display picture lively
Visual and sound effects.Samuel doctor Hurst has invented a touch sensor in 1971, this sensor is exactly touch screen
Blank.After 3 years, he devises the transparent touch screen of first item.1977, touch screen technology was greatly improved, always
It is still being widely used and is developing rapidly to today.Handset touch panel is divided into two kinds: touch screens and capacitance plate, currently a popular
Touch screen majority is all lens screen, is exactly pure flat resistance and mirror surface capacitance plate, and Nokia's majority is all touch screens, capacitance plate
It is represented as iphone.Resistance touch screen is commonly called as " soft screen ", is chiefly used in the mobile phone of Windows Mobile system;Capacitance touch screen is commonly called as
" hard screen ", such as iPhone and G1 machine use this screen matter.
Touch sensing is the core component of touchscreen, at present mainly using metal lead wire is arranged on transparent ITO conductive film,
ITO conductive film is used for touch sensible, and metal lead wire is for conducting electric signal, to realize that touch-control senses.Touch sensing is divided into
Visible area and metal lead wire area, visible area touch the position of screen display shadow, the setting of metal lead wire area as mobile phone screen etc.
On the periphery of ITO conductive film, in application, generally being blocked by opaque material, then it is presented on the non-inductive position in Mobile phone screen periphery.But
It is that ITO conductive film high-temp resisting high-humidity resisting effect is poor, and bending resistance is poor, therefore, many scientists are seeking a kind of better material
Material.
The electric conductivity of transparent graphene conductive film and sensitivity are high, and prominent with graphene electrically conducting transparent my slight skill art flies
The development pushed ahead vigorously, the further mature of production line, production cost reduce than before.Graphene conductive film touch sensing is absurd fantastic therewith
It is raw, but apply causes the superiority for failing to make graphene conductive film to be brought into play there are many problems.Existing graphene
Transparent conductive film is applied insufficient in touch sensing field tool following points:
1. generalling use adhesive means transfer graphene (Applied Physics to meet attachment force request
Letters, 2013,102 (2): 023112.), it is difficult to use bilayer graphene film (excellent electrical properties), even if using double-deck
Graphene film (Nature nanotechnology, 2010,5 (8): 574-578.), manufacture graphene touch sensing or
Be also when touch screen use more complicated manufacturing method (Chinese invention patent application number: 201510983770.7 with
201510998462.1), and because TRT or the graphene film adhesive force of electrostatic transfer method transfer are poor, touch-control sensing is influenced
The production yield and reliability of device or touch screen;
2., when manufacturing graphene touch sensing or touch screen, being passed using the graphene film of adhesive means transfer
Sensor surfaces metal electrode, as silver paste its surface adhesion force also without competitive materials (such as: ITO conductive film, nano-silver thread
Conductive film) adhesive force it is good, influence production yield and reliability;
3., when manufacturing graphene touch sensing or touch screen, being using the graphene film of adhesive means transfer
Ensure that there is good adhesive force, generally use single-layer graphene, cause electrical property it is poor (sheet resistance generally 170ohm/sq with
On, sheet resistance inhomogeneities is ± 10% or more), it is difficult to it applies in high-performance, large touch sensor and touch screen, and side
Resistance uniformity difference is easy to cause capacitance touching control sensor passage capacitance bad, influences production yield and product is used for a long time
Reliability.
Summary of the invention
In view of the above-mentioned deficiencies in the prior art, it is an object of the present invention to provide a kind of composite membrane touch-control sensing of new type
Device, high sensitivity, high temperature resistant moisture-proof and transparency conducting layer sheet resistance is uniform, stability is strong;
It is a further object of the present invention to provide the preparation methods of above-mentioned composite membrane touch sensing, and method is simple and easy, at
This is low, is suitable for industrialized large-scale production.
The purpose of the present invention is achieved by the following technical scheme:
A kind of composite membrane touch sensing, including substrate, IT0 conductive film, graphene layer and metal electrode, the substrate,
ITO conductive film and graphene layer successively fit closely, wherein the metal electrode is connect with ITO conductive film.
Preferably, the graphene layer is one or more layers graphene film, preferably one layer of graphene.By ITO conductive film
Combine with grapheme conductive film, one layer of graphene can be realized extraordinary electric conductivity, sheet resistance 70-80ohm/sq, far
Lower than general commercial transparent conductive film.
Preferably, the overall thickness of the transparent substrates and ITO layer is 1-500 μm, such as: 1 μm, 5 μm, 10 μm, 20 μm, 50
μm, 100 μm, 200 μm, 250 μm, 300 μm, 500 μm, etc.;It is preferred that 125 μm;It is further preferred that the ITO with a thickness of 1-
500nm, such as: 1nm, 2nm, 5nm, 10nm, 50nm, 100nm, 200nm, 300nm, 400nm, 500nm, etc.;It is preferred that 35nm.
Preferably, the ITO layer has the metal electrode of a pattern layers in the one side being bonded with graphene layer.For example,
Using the ITO with pre- plated film in the market.After pre- plated film is patterned, as metal electrode.Preferably copper plating film.
Preferably, the metal electrode uses ag paste electrode or copper electrode.
Composite membrane touch sensing of the present invention, there are three types of preparation methods, are specifically detailed in following explanation.
Preparation method one:
Include the following steps:
1) one or more layers graphene film is shifted on the ITO conductive film with substrate;
2) graphene film is patterned, keeps the graphene film as touch sensing metal lead wire region clear
It removes, exposes ITO conductive film surface;
3) metal electrode is made on the surface ITO for exposing metal lead wire area;
4) laser patterning process, preferably laser direct-writing pattern are implemented to metal electrode and other graphene overlay areas
Change, forms touch sensing pattern and surrounding metal lead;
5) it is bonded optical cement, that is, forms the touch sensing with complete structure and function.
ITO conductive film with substrate is the ito film sold on existing market, including basal layer (generally PET) and
ITO conductive membrane layer.
Preferably, in the step 1), the transfer method of graphene is using heat release adhesive tape transfer method or electrostatic transfer
Method, preferably electrostatic transfer method;It is preferred that one layer of graphene film of transfer.
Heat release adhesive tape transfer method, referring to Nature nanotechnology, 2010,5 (8): 574-578. utilizes glue
Film is by graphene that CVD method is grown by being transferred to target substrate in growth substrates.
Electrostatic transfer method, referring to Chinese invention patent application number: 201210269206.5,201410238058.X.This hair
It is bright that graphene is preferably shifted using electrostatic transfer method, through the present inventor the study found that when graphene film interface and ITO are contacted,
Interfacial cleanliness degree influences the sheet resistance of composite conductive film after transfer very big.Therefore, general adhesive transfer method can not be applicable in
In compound membrane process proposed by the present invention, adhesive tape (TRT) transfer method or PMMA transfer method etc. are discharged for heat, because its surface has greatly
The residue of amount influences the contact performance of graphene film and ito thin film, only preferably uses this big ruler of electrostatic transfer method
Very little/clean transfer techniques, are just able to achieve optimum efficiency of the invention.Further, since the surface ITO covers graphene film, because
Even if the defects of a small amount of crackle occurs in this ito thin film, graphene film can also realize that bridge joint acts on, significant increase ito thin film
Bending resistance characteristic.
After realizing ito film in conjunction with graphene film using electrostatic transfer method, composite conductive film sheet resistance is up to 70-80ohm/
Sq, the conductivity than individual ito film improve by about one time, therefore, only need to shift one layer of graphene, can be realized powerful enough
Sensitivity gets rid of the poor problem of one layer of graphene touch-control sensitivity of existing graphene touch sensing.
Preferably, in the step 2), the Patternized technique uses write-through laser ablation method, yellow light method, sacrificial layer
Method, preferably laser ablation method.Preferably, the write-through laser ablation method is scanned using the laser (1064nm wavelength) of power 3W
Twice.
Method is repeatedly cleared away using small-power, it is ensured that cleaning graphene, but do not damage ITO;It is differentiable whole to obtain
A viewfinder area and metal lead wire area.
Write-through laser ablation method: using the scheme of write-through laser ablation, adjusting laser parameter, so that laser ablation/
Graphene film is peeled off, but the not ITO in pattern of lesions region (metal lead wire area), this scheme is preferred embodiment.
Yellow light method: using yellow light process program, in graphene film surface coating photoresist or pressing photosensitive dry film, then
Using the standard yellow light technique in micrometer-nanometer processing technology, patterned photoresist/dry film is formed, is finally carved using oxygen plasma
The technology of erosion, removal need patterned graphene, finally by cleaning of removing photoresist, can be obtained target pattern (graphene film).
Sacrificial layer method: in one layer of peelable glue/hydrosol (sacrificial layer) of ITO surface printing of graphene film to be transferred, or
One layer photoresist/dry film fine pattern (sacrificial layer) is formed using yellow light scheme, graphene film is then shifted, finally removes sacrificial
Domestic animal layer material and cleaning, can be obtained graphene pattern structure.
Preferably, in the step 3), gold is arranged at graphene pattern area (ITO exposed region) in the method by printing silver paste
Belong to electrode;Preferably, the print thickness of silver paste is 4-8 μm, the baking condition of silver paste are as follows: 135 DEG C of baking 40min;
Preferably, in the step 4), laser direct-writing patterning, shape are carried out to viewfinder area ITO/ graphene and metal electrode
At touch sensing pattern and surrounding metal lead.At this point, needing to increase power to 9W, lead district need to be swept twice when patterning
It retouches, 1 scanning in viewfinder area.
Preparation method two:
Include the following steps:
1) first the metal film on existing pre- plated film ITO is patterned, forms metal electrode, the pre- plated film ITO
It is preferred that having the ITO conductive film of copper plating film;
2) one or more layers graphene film is shifted on the surface for the ITO for being equipped with metal electrode again;
3) laser direct-writing patterning is carried out to viewfinder area ITO/ graphene and metal electrode, formed touch sensing pattern and
Surrounding lead;
4) it is bonded optical cement, that is, forms the touch sensing with complete structure and function.
Pre- plated film ITO (such as dedicated ITO of metal process for copper), is to be coated with some very thin metals, such as copper on ito film surface
Film is well known to those skilled in the art technology, is commercially available.
Preparation method three:
Include the following steps:
1) in the ITO conductive film surface printing silver paste metal electrode for having substrate, it is preferred that the print thickness of silver paste is 6-
8 μm, the baking condition of silver paste are as follows: 135 DEG C of baking 40min;
2) one or more layers graphene film is shifted in the ITO conduction film surface for being equipped with silver paste metal electrode, preferably shifted
One layer;
3) laser direct-writing patterning is carried out to viewfinder area ITO/ graphene and ag paste electrode, formed touch sensing pattern and
Surrounding lead;
4) it is bonded optical cement, that is, forms the touch sensing with complete structure and function.
In three of the above preparation method, method is third is that the scheme that the present invention optimizes the most, and material is easy to get, simple process, at
This is low, yield is high.
The principle of the invention:
For graphene film in the problems in touch sensing application field, present invention employs a kind of composite graphite alkene
Transparent conductive film proposes a kind of new graphene touch sensing manufacturing method, solves graphene film and passes in touch-control
The problems applied in sensor:
1. manufacturing graphene touch sensing process in one layer of graphene film of Indium-tin Oxide Transparent Conductive Film surface recombination
In, sensor metal lead wire is set to the surface ITO, thoroughly solving metal lead wire, poor adhesive force is asked on the surface of graphene
Topic, whole processing procedures are compatible with existing tin indium oxide touch sensing processing procedure, improve sensor production yield and reliability;It is solving
During adhesive force, has both and solve the problems, such as that single-layer graphene film electrical property and optical property are bad.
2. in one layer of graphene film of Indium-tin Oxide Transparent Conductive Film surface recombination, graphene film hydrophobicity, carbon material
Chemical stability can prevent influence of the steam to indium tin oxide material, improve working in harshness for graphene touch sensing
Under the conditions of stability, for open up graphene touch sensing application field have biggish meaning.
Currently invention addresses adhesion problem point of the graphene film in touch sensing manufacturing process is solved, to improve
The shortcomings that graphene touch sensing production yield and product stability are final purpose, have abandoned traditional single film, utilizes stone
Black alkene/tin indium oxide composite conductive film is arranged touch sensing metal electrode on the surface ITO, thoroughly solves graphene film
Adhesion problem during sensor production, for pushing application of the graphene film in senser element that there is important meaning
Justice, while can also solve that pure ito thin film high-temp resisting high-humidity resisting effect is poor, the problem of bending resistance difference.
The invention has the advantages that:
1. relatively existing ito thin film touch sensing
(1) block-water performance is good, and graphene film has hydrophobic property, improves high humidity environment reliability;
(2) bending resistance is promoted to a certain extent, because graphene can play the role of bridge joint when ITO bends damaged,
Inhibit aisle resistance bad.
2. relatively existing graphene film touch sensing
(1) metal lead wire adhesion problem is solved;
(2) solve the problems, such as that sheet resistance of graphene thin film uniformity is poor, sheet resistance is too big.
In the prior art, the touch sensing of ito thin film manufacture, the problems such as being easy to produce crackle, influences flexible device
Application and reliability.As flexible device rapidly develops, ito thin film increasingly loses its advantage, needs better film
Substitution.The present invention is compound by graphene film, plays the role of bridge joint to ito thin film surface, will not even if ITO is impaired
Loss of function improves the reliability of device.The electrostatic transfer method for cooperating the applicant exclusive, graphene film is transferred to
Ito thin film surface realizes the clean quiet and large scale transfer of graphene film.As it can be seen that the present invention complies with the demand of flexible device,
The leading contact resistance that realizes is bordering on zero, composite membrane sheet resistance small (70-80ohm/sq), flexible (is folded to for continuous 1,000,000 times small
Still keep good performance in 20 degree of angle foldings), the laminated film touch sensing that is combined, provide that accuracy is high, can roll over
Folded touch screen has opened up new field for electronic industries such as mobile phones.As it can be seen that composite membrane touch sensing of the present invention produce it is imaginary
Less than technical effect.
Figure of description
Fig. 1 is the composite conductive film planar structure schematic diagram that embodiment 1 has electrode;
Fig. 2 is the composite conductive film the schematic diagram of the section structure that embodiment 1 has electrode;
Fig. 3 is one process flow chart of the method for the present invention (embodiment 2,3,4);
Fig. 4 is two process flow chart of the method for the present invention (embodiment 5);
Fig. 5 is three process flow chart of the method for the present invention (embodiment 6);
Wherein, 1- graphene film, 2-ITO conductive film, 3- metal electrode, 4- substrate (PET), 5- sacrificial layer (peelable indigo plant
Glue, photosensitive dry film, photoresist etc.).
Specific embodiment
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, it should be understood that preferred reality described herein
Apply example only for the purpose of illustrating and explaining the present invention and is not intended to limit the present invention.
Embodiment 1:
A kind of composite membrane touch sensing is made of the composite conductive film with metal electrode, referring to Fig. 1,2, including base
Bottom 4, IT0 conductive film 2, graphene layer 1 and metal electrode 3, the substrate 4, ITO conductive film 2 and graphene layer 1 are successively close to be pasted
It closes, wherein the metal electrode 3 is connect with ITO conductive film 2.
Embodiment 2:
A kind of manufacturing method of composite membrane touch sensing, process flow is referring to attached drawing 3, comprising the following steps:
(1) in commercial 125 microns of thickness ITO conductive film (including substrate 4, ITO conductive film 2) surface printing peelable blue gels 5
(sacrificial layer), blue glue 5 then use 135 DEG C, 40min condition with a thickness of 10-50 microns in ir tunnel furnace or clean oven
Drying is stand-by, wherein blue glue forms blocked area on the surface ITO, which forms touch sensing metal lead wire wiring region
Domain;
(2) graphene film 1 is shifted in the surface ITO that step (1) has printed peelable blue gel 5, is turned using electrostatic transfer method
Graphene is moved, graphene number of plies is single or double layer;
(3) peelable blue gel is removed, being transferred to the graphene above peelable blue gel can be removed simultaneously, and result in formation of touchings
It controls sensor metal lead wire wiring area (patterned Graphene);
(4) in patterned Graphene region type metal silver paste 3, so that silver paste is contacted with ITO conductive film, then
135 DEG C are used in ir tunnel furnace or clean oven, the drying of 40min condition;
(5) using the technique of laser direct-writing etching, laser ablation processing is carried out to step (4) sample, is directly formed visual
Area's transparent electrode pattern and lead district electrode pattern;
(6) fitting Optical transparent adhesive (OCA) is used as protective layer, forms the touch sensing with complete structure and function.
Embodiment 3:
A kind of manufacturing method of touch sensing, process flow is referring to attached drawing 3, comprising the following steps:
(1) photosensitive dry film 5 is pressed on commercial 125 microns of thickness ITO conductive film (including substrate 4, ITO conductive film 2) surfaces
(sacrificial layer), photosensitive dry film is with a thickness of 10 microns;
(2) standard patterning processing procedure is carried out to photosensitive dry film, i.e., by exposure, developing manufacture process, on 2 surface of ITO conductive film
Blocked area is formed, which forms touch sensing metal lead wire wiring area;
(3) graphene film 1 is shifted in the patterning dry film surface of step (2) formation and other ito thin film surfaces, used
Electrostatic transfer method shifts graphene, and graphene number of plies is single or double layer, preferred single layer;
(4) using photosensitive dry film remover removal dry film and its surface graphene, cleaning, drying, result in formation of touch-control biographies
Sensor metal lead wire wiring area (patterned Graphene);
(5) in patterned Graphene region type metal silver paste 3, so that silver paste is contacted with ITO conductive film 2, then
135 DEG C are used in ir tunnel furnace or clean oven, the drying of 40min condition;
(6) using the technique of laser direct-writing etching, laser ablation processing is carried out to step (5) sample, is directly formed visual
Area's transparent electrode pattern and lead district electrode pattern;
(7) fitting Optical transparent adhesive (OCA) is used as protective layer, forms the touch sensing with complete structure and function.
Embodiment 4:
A kind of manufacturing method of touch sensing, process flow is substantially with embodiment 2, the difference is that graphene pattern
Change the technique using laser direct-writing etching, specifically includes the following steps:
(1) graphene film is shifted on commercial 125 microns of thickness ITO conductive film (including substrate 4, ITO conductive film 2) surfaces
1, graphene is shifted using electrostatic transfer method, graphene number of plies is single or double layer, preferred single layer;
(2) using the technique of laser direct-writing etching, 2 surface graphene film 1 of ITO conductive film is handled, adjustment swashs
Optical parameter makes laser only have etching (patterning) effect to graphene film 1, without damaging ITO conductive film 2, so as to
Patterned graphite film is obtained, metal lead wire area ITO is exposed;
(3) in patterned Graphene region type metal silver paste 3, so that silver paste is contacted with ITO conductive film, then
135 DEG C are used in ir tunnel furnace or clean oven, the drying of 40min condition;
(4) using the technique of laser direct-writing etching, laser ablation processing is carried out to step (3) sample, is directly formed visual
Area's transparent electrode pattern and lead district electrode pattern;
(5) fitting Optical transparent adhesive (OCA) is used as protective layer, forms the touch sensing with complete structure and function.
Embodiment 5:
A kind of manufacturing method of touch sensing, process flow is referring to attached drawing 4, comprising the following steps:
(1) using commercial copper facing ito thin film (125 microns of thickness), including substrate 4, ito thin film 2, copper film 3 are (as metal electricity
Pole), using standard yellow light operation processing procedure, i.e. coating photoresist/press dry film, exposure development, etching metallic copper, remove photoresist, clean baking
Dry operation processing procedure forms the sensor metal lead areas formed by thin copper film (lead itself is not patterned);
(2) graphene film 1 is shifted in 2 surface of ITO conductive film containing metal lead electrode 3 that step (1) is formed, adopted
Graphene is shifted with electrostatic transfer method, graphene number of plies is single or double layer;
(3) using the technique of laser direct-writing etching, laser ablation processing is carried out to step (2) sample, is directly formed visual
Area's transparent electrode pattern and copper lead district electrode pattern;
(4) fitting Optical transparent adhesive (OCA) is used as protective layer, forms the touch sensing with complete structure and function.
Embodiment 6:
A kind of manufacturing method of touch sensing, process flow is referring to attached drawing 5, comprising the following steps:
(1) in commercial 125 microns thick ito film (including substrate 4, ITO conductive film 2) surface printing metal silver paste leads
Electrode 3 uses 135 DEG C in ir tunnel furnace or clean oven, and the drying of 40min condition is stand-by;
(2) graphene film 1 is shifted on 2 surface of ITO conductive film containing metal lead electrode formed to (1),
Graphene is shifted using electrostatic transfer method, graphene number of plies is single or double layer;
(3) using the technique of laser direct-writing etching, laser ablation processing is carried out to step (2) sample, is directly formed visual
Area's transparent electrode pattern and silver paste metal lead wire area electrode pattern;
(4) fitting Optical transparent adhesive (OCA) is used as protective layer, forms the touch sensing with complete structure and function.
The foregoing is only a preferred embodiment of the present invention, is not intended to restrict the invention, although referring to aforementioned reality
Applying example, invention is explained in detail, for those skilled in the art, still can be to aforementioned each implementation
Technical solution documented by example is modified or equivalent replacement of some of the technical features.It is all in essence of the invention
Within mind and principle, any modification, equivalent replacement, improvement and so on be should all be included in the protection scope of the present invention.