Prior art
In the actual use of liquid crystal indicator, especially in adopting the portable information terminal device or portable phone of liquid crystal indicator, the key issue that needs to solve is to make light-duty and slim liquid crystal panel.
Carried out a lot of effort and overcome this type of problem as the density by reducing glass substrate or the thickness that makes glass substrate are thinner.When reducing the density of glass, the silicon dioxide (SiO of main composition glass
2) having determined all physical characteristicss of glass basically, the technology that further reduces glass density faces its limit, therefore, is difficult to further reduce the density of glass.On the other hand, when making the slab-thickness attenuation, the intensity of glass substrate sharply descends, and makes device on the production line be forced to carry out change to a certain degree, the physical strength step-down of opposing external force.Therefore, can say and to be fabricated to 0.4 to the thickness of glass substrate to 0.5mm, as its minimum value.
Obtain light-duty and liquid crystal panel thin type structure as a kind of, exemplified the single color LCD panel that is referred to as the simple matrix type that does not adopt active component such as TFT (thin film transistor (TFT)) to drive liquid crystal.In this liquid crystal panel, the material that constitutes matrix is formed by the transparent electrode material that is called ITO, and forms under relatively low temperature, so may use plastic or form the analog of transparent electrode material thereon.The plastic that will have this class formation in fact, is used in portable information terminal device and the portable phone.
Trend as display panels, observe a kind of like this phenomenon: along with the raising of recent portable terminal performance, the quantity of information that can be treated to display message is also increasing always, and image to be shown also becomes colour and moving image respectively from monochromatic and rest image.
Yet simple matrix type liquid crystal indicator adopts STN (super-twist nematic) liquid crystal display pattern as the liquid crystal drive pattern, so simple matrix type liquid crystal indicator has following shortcoming.Just, with adopt TN (twisted nematic) liquid crystal display pattern with TFT and be used for popular comparing with the notebook type personal computer that widely uses or the active matrix type liquid crystal indicator of monitor, simple matrix type liquid crystal indicator does not provide the quality of enough image to be shown to the user, make gray scale show and worsen that perhaps the user feels that residual image is arranged.
Consider the problems referred to above, developed and in such as Japanese Laid-Open Patent Application 212116/1999 and Japanese Laid-Open Patent Application 116158/1997, disclose following technology.Just, on plastic, form active component such as TFT element.In previous disclosing, on glass substrate, form active component, then plastic is added on the surface of a side of glass substrate installation elements, and then, along the part of a side of the not installation elements of the thickness direction abrased glass substrate of substrate, to remove glass substrate.Back one open in, on the plastic or thickness be not more than on the glass substrate of 0.5mm and form active component.Yet, found in the device that adopts plastic, still will solve many technical matterss, and the equipment of this type of matching requirements costliness, thereby hinder this device is tried out.
On plastic, have in the liquid crystal indicator of colored filter and active component, the plastic that forms colored filter thereon shows the heat-resisting and anti-dissolving power of going on business, therefore the pigment and the dissolving power that can be used as colored filter are restricted, thereby can't obtain colored replicability fully.Therefore, the liquid crystal indicator that needs exploitation to have following structure and advantage strongly.Just, form a kind of lighter and thinner liquid crystal indicator, further form to work in mode identical under the situation of TN liquid crystal mode and carry out work with colored and active matrix liquid crystal display panel.
And, even adopting plastic to make under the lighter and thinner situation of liquid crystal indicator, except the heat-resisting and anti-dissolving power performance of difference, plastic has following problem: the plastic easy deformation, therefore, compare with the situation of handling glass substrate, be difficult to handle plastic according to the step of making liquid crystal panel.
Summary of the invention
Therefore, an object of the present invention is to provide a kind of method of making liquid crystal indicator, in described liquid crystal indicator, adopt the TFT substrate, and can form lighter and thinner liquid crystal simultaneously.
A kind of method of making according to liquid crystal indicator of the present invention is constructed as follows.This method comprises:
Place the TFT substrate and make it to be spaced from each other the step of a preset distance in the face of the reverse side substrate of TFT substrate; With
With the step in space between liquid filling TFT substrate and reverse side substrate,
Wherein, like this structure liquid crystal indicator: at least TFT substrate and reverse side substrate one of them constitute by plastic, and then so constitute this method: this method comprises cutting and the substrate segmentation procedure of separating the combined substrate of being made up of TFT substrate and reverse side substrate, two substrates are put into substrate unit with the liquid crystal between them, by a surface of support substrates support plastic, up to cutting and separating described combined substrate.
As mentioned above, in the method for making liquid crystal indicator, by plastic being used as of two substrates constituting liquid crystal panel, with have be used in liquid crystal panel in the situation of glass substrate of identical thickness of plastic compare, it is light-duty can making liquid crystal panel.And, making plastic, compare with the thickness of glass substrate to have under the crash-resistant situation identical with glass substrate, can reduce the thickness of plastic, thereby make liquid crystal panel have thinner thickness.
Said method has following concrete steps.That is, the method for this manufacturing TFT substrate comprises:
On first substrate, form the step of thin film transistor (TFT) and wiring;
On first substrate, place the step of the diaphragm of cover film transistor and described wiring;
Forming corresponding to the color layer of thin film transistor (TFT) on the diaphragm and preventing that illumination is mapped to the step of the black matrix on the thin film transistor (TFT);
On diaphragm, place the step of the planar film that covers color layer and black matrix;
Open the part of diaphragm and planar film, in diaphragm and planar film, to form the step of the contact hole of the source electrode that reaches thin film transistor (TFT);
On planar film, form the step that covers contact hole and be connected to the transparent pixels electrode of source electrode;
On planar film, form the step of spacer;
On planar film, form the alignment films that covers transparent pixels electrode and spacer, grind the step of alignment films then;
On alignment films, form encapsulant to surround the step of presumptive area; With
Liquid crystal splashed in the zone that surrounds by the encapsulant that constitutes alignment films and
A kind of method of making the reverse side substrate comprises:
Cover second substrate and support substrates is adhered to the step on the surface of described second substrate with transparent electrode, described surface is positioned at described second substrate side opposite with described transparency electrode; With
On described transparency electrode, be formed for the material of alignment films, and grind subsequently described alignment films step and
The method of making liquid crystal indicator further comprises:
Overlap the to each other and place described TFT substrate and reverse side substrate, make the alignment films of described TFT substrate and described counter substrate face mutually, make the described alignment films of described reverse side substrate contact the step of spacer and the encapsulant of described TFT then;
Solidify described encapsulant,, thereby form the step of half-finished panel so that described TFT substrate and described reverse side substrate adhere to mutually;
Take off the step of described second substrate from described support substrates;
The step of described half-finished panel being cut apart and is divided into panel unit; With
Polarizer is attached to the surface of described at least first substrate in described first and second substrates that constitute described panel unit, described surface be positioned at described liquid crystal reverse side and
Before forming the described step of described transparency electrode on described second substrate, earlier described support substrates is attached to the surface of described second substrate, described surface is placed the reverse side of described transparency electrode.
In addition, said method has following other structure.Promptly, be arranged in the step of the reverse side of described liquid crystal at least on the described surface of aforesaid surface that polarizer is attached to described at least first substrate in described first and second substrates that constitute described panel unit and described the first substrate, only described polarizer is attached on the described surface of described first substrate, and described second surface adds plastic by polarizer and forms.
As mentioned above, outside described first and second substrates, adopt polarizer to add plastic, make to form to obtain the second thinner substrate of thickness, and form thin more liquid crystal panel than the use glass substrate as described second substrate.
Embodiment
Referring now to Fig. 1, the first embodiment of the present invention is described.Fig. 1 is that described plane is perpendicular to described substrate along the cut-open view that cuts open the liquid crystal panel of getting by the plane of the TFT on the TFT substrate.
As shown in Figure 1, on TFT, form colored filter 108 and black matrix by exposure or similar mode, and on colored filter and black matrix, form pixel electrode 112 and column spacer 113, thereby form TFT substrate 100 through external coating 110.By on plastic 201, forming the reverse side substrate 200 that reverse side electrode 202 forms in the face of TFT substrate 100.
Compare with the situation of glass substrate, use plastic 201, can make liquid crystal panel lighter with the thickness that equates with the thickness that uses plastic 201.And, have under the situation of identical anti-collision ability plastic 201 being made with glass substrate, compare with the thickness of glass substrate, can reduce the thickness of plastic, thereby make liquid crystal panel have thinner thickness.
On the glass substrate 101 of TFT substrate 100, form amorphous silicon (a-Si) layer 104.On a-Si layer 104, form colored filter 108 and black matrix 109, and further form external coating 110, to cover colored filter and black matrix.And then, in the contact hole 111 that external coating 110 forms, form the pixel electrode 112 that transparent metal constitutes.Placement has the TFT substrate 100 of above-mentioned film and faces reverse side substrate 200 across the column spacer, separates several microns distance with the reverse side substrate simultaneously, and liquid crystal 115 is inserted between TFT substrates 100 and the reverse side substrate 200.
In the liquid crystal panel that constitutes as mentioned above, plastic 201 is made up of polycarbonate, polyethersulfone, polyarylate or analog.Because the glass substrate of the weight ratio same thickness of plastic 201 is littler, can make liquid crystal indicator lighter.And, in that plastic manufacturing and glass substrate are had under the situation of identical anti-collision ability, compare with glass substrate, can reduce the thickness of plastic, thereby make liquid crystal panel thickness thinner.
By manufacturing step as shown in Figure 2, with the reverse side substrate that adopts the plastic 201 of this embodiment panel of packing into.With reference to figure 1, introduce a kind of case method: make have expect the liquid crystal panel of substrate as the reverse side substrate.
At first, in TFT substrate 100, the pixel electrode 112 that on glass substrate 101, forms gate electrode 102, gate insulating film 103, a-Si layer 104, data line 105 and source electrode 106, passivating film 107, colored filter 108, black matrix 109, external coating 110, contact hole 111 successively and form by transparent metal.
In TFT substrate 100, before forming pixel electrode 112, utilize spin coating method or printing process to apply the colored resist of forming by photosensitive acrylic resin, to form the colored resist of homogeneous film thickness, afterwards, expose, develop and cure with respect to color separately, thereby form colored filter 108 at given position subsequently.
Then, use the coating method that is similar to colored method against corrosion on presumptive area, to apply the black resist of forming by photosensitive acrylic resin, and carry out etching to form black matrix 109.
Then, the coating method that use is similar to the method for colored resist applies the transparent resist of being made up of photosensitive acrylic resin as external coating (organic interlayer dielectric) 110 on presumptive area, and forms contact hole 111 by opening portion and the passivating film on source electrode 106 107 at external coating 110.Then, form the pixel electrode of forming by transparent metal 112, cover contact hole 111, so that pixel electrode 112 and source electrode 106 interconnect.
And then coating has the photosensitive acrylic resin of the film thickness that is substantially equal to form the required gap of panel on external coating 110, and temporarily cures with 60~120 ℃ temperature, uses mask to expose, to form the figure of being scheduled in resin.Afterwards, the tree of having exposed is developed, cure with 200~250 ℃ temperature then, have the column spacer 113 of predetermined profile with formation.
Introduce the method for making reverse side substrate 200 below.
At first, by bonding, negative-pressure adsorption (being used to produce the method for negative pressure) or similar approach the plastic 201 with thickness of 0.1-0.7mm is fixed to the glass substrate of slab-thickness with 0.4-1.1mm (not shown) with the adsorption plastic substrate.The thickness of glass substrate is can be elective, makes the total thickness of glass and plastic not need the special modification to manufacturing step after plastic is attached to glass substrate.And, when glass substrate and plastic mutual when bonding, can heavily shell contact adhesive (pressure sensitive adhesive of being convenient to peel off) as from such as based on the bonding agent of natural rubber, acryloid cement, be added on the surface of glass substrate by spin coating, printing process or similar approach applying adhesive one side based on glass paper tape (cellophane band) or the sealer (seal) selected synthetic rubber binder, the material group based on silicone rubber adhesive, afterwards, plastic 201 is adhered to glass substrate.Note, silicones or analog can be added to plastic coating on the surface of bonding agent, so that in step subsequently, peel off.In addition, glass substrate and plastic do not require to have area identical, and plastic 201 can be bigger a little than glass substrate, so that peel off in step subsequently.
Be added on the plastic 201 by the transparent resist that carries out vacuum sputtering or will include ITO particle or analog, on plastic 201, to form the public electrode 212 that constitutes by transparent metal.In the case, no matter the state of film during forming film and afterwards just, carry out the film of deposit or coating is become from amorphous state the thermal treatment of crystalline state with the temperature of the heat resisting temperature that is not higher than plastic 201.
Then, be presented in the method for making in the panel step that is used for TFT substrate 100 and 200 assemblings of reverse side substrate.
At first, the material of being made up of polyimide or analog that will be used for alignment films by printing, coating or similar means is added to presumptive area equably, to obtain predetermined thickness, cure presumptive area then as the surface of TFT substrate 100, side with the liquid crystal place of reverse side substrate 200, specifically, in a side of placing pixel electrode 112 and public electrode 212 respectively.In the case, cure not to be higher than at least with respect to the temperature of the heat resisting temperature of the plastics of plastic 201.
Then, arrange along constant direction for making liquid crystal, the material that is used for alignment films that forms on the surface of separately substrate with the polishing of cloth or analog is to form alignment films 114 (grinding process).
Afterwards, be added on (draw on) TFT substrate by the encapsulant of distribution method (dispenser method), liquid crystal 115 be filled in by the sealer area surrounded by utilizing drippage (dropping) technology to inject liquid crystal with the ultraviolet curing type.Although in this example, introduced in this embodiment on TFT substrate 100 and formed sealer, liquid crystal 115 is filled in by in the sealer area surrounded, this method is not limited to this example, can on reverse side substrate 200, form sealer, liquid crystal 115 can be filled in the zone that is limited by sealer.
Then,, therein, filled liquid crystal 115 with reverse side substrate 200 and the 100 overlapping placements of TFT substrate, and with ultraviolet ray from the negative substrate 200 1 sides shine hermetic unit, to solidify sealer.
Afterwards, the glass substrate that will adhere on the plastic 201 according to following mode is removed from plastic 201.Promptly, glass substrate is being fixed under the situation of plastic 201 by bonding agent, according to the mode that the end of the end of glass substrate and plastic is separated along mutually opposite direction glass substrate is removed from plastic 201, in described mode, its operation is similar to the operation of seeing in peeling off glass paper tape and sealer.On the other hand, under situation about by negative-pressure adsorption glass substrate being fixed on the plastic 201, by negative pressure destruction being separated from each other out glass substrate and plastic 201 for air pressure according to nondestructive mode.Afterwards, will substrate that constitute be divided into the substrate of specific size by TFT substrate 100 and reverse side substrate 200 is bonding mutually, and polarizer 116 that is used for the TFT substrate and the polarizer 216 that is used for the reverse side substrate are adhered to two apparent surfaces of substrate respectively, thereby finished the formation of liquid crystal panel.Note, behind the surface of cleaning glass substrate, can utilize the glass substrate of from plastic, taking off again according to nondestructive mode.In the case, use alcohol or petroleum base organic solvent to remove bonding agent or the analog that adheres to glass substrate.
As mentioned above, according to the manufacturing step that is used to finish the reverse side substrate of forming by plastic 201 200, the step before from the step that forms public electrodes in plastic 201 to the step of reverse side substrate 200 being cut apart and is divided into liquid crystal panel unit, glass substrate is adhered to plastic, as the support substrates of plastic.Therefore, can prevent of the negative effect of the amount of deflection of plastic, thereby allow to handle plastic with the same procedure of handling glass substrate to the manufacturing liquid crystal panel.
Now, 3 and 4 introduce the second embodiment of the present invention with reference to the accompanying drawings.
In first embodiment, although with the substrate cutting and after being divided into liquid crystal panel polarizer is being adhered to plastic, second embodiment introduces a kind of method of making liquid crystal panel, wherein function of polarization is given in the plastic earlier.
According to steps flow chart shown in Figure 4, will be assembled in the panel at the reverse side substrate 300 of the present embodiment shown in Fig. 3, described reverse side substrate 300 uses plastic 301 with function of polarization (below be referred to as polarization add plastic 301).At length introduce exemplary method below.Notice that the method for making CF-on-TFF substrate 100 is identical with the method for first embodiment, therefore, has omitted explanation wherein.
At first, be that the polarizer of 0.1-0.7mm adds plastic 301 and is fixed to and has the glass substrate that slab-thickness is the 0.4-1.1mm (not shown) by bonding, negative-pressure adsorption (being used to produce the method for negative pressure) or similar approach with having film thickness with the adsorption plastic substrate.The thickness of glass substrate is can be elective, makes the total thickness of glass after polarizer being added plastic be attached to glass substrate and plastic not need the specific modification to manufacturing step.And, to add plastic mutual when bonding when glass substrate and polarizer, can heavily shell contact adhesive (pressure sensitive adhesive of being convenient to peel off) as from such as based on the bonding agent of natural rubber, acryloid cement, be added to glass substrate based on glass paper tape or the sealer (seal) selected synthetic rubber binder, the material group based on silicone rubber adhesive, place by spin coating, printing process or similar approach on the surface of bonding agent one side, afterwards, polarizer is added plastic 301 and be adhered to glass substrate.Note, silicones or analog can be added to the polarizer that should place bonding agent and add on the surface of plastic 301, so that in step subsequently, peel off.In addition, glass substrate and polarizer add plastic and do not require to have area identical, and polarizer adds plastic 301 can be bigger a little than glass substrate, so that peel off in step subsequently.
Then, be added to polarizer by the transparent resist that carries out vacuum sputtering or will include ITO particle or analog and add on the plastic 301, form the public electrode of forming by transparent metal 312 on the plastic 301 to add at polarizer.In the case, no matter how, during forming film and afterwards just the state of film, carry out deposit or the film that applies are become from amorphous state the thermal treatment of crystalline state not to be higher than temperature that polarizer adds the heat resisting temperature of plastic 301.
Then, be presented in the method for making in the panel step that TFT substrate 100 and reverse side substrate 300 are assembled.
At first, the material of being made up of polyimide or analog that will be used for alignment films by printing, coating or similar means is added to presumptive area equably, to obtain predetermined thickness, cure presumptive area then as the surface of TFT substrate 100, and the side that reverse side substrate 300 is placed liquid crystal 115, specifically, in a side of placing pixel electrode 112 and public electrode 312 respectively.In the case, cure not to be higher than at least the temperature of heat resisting temperature that adds the plastics of plastic 301 with respect to polarizer.
Then, arrange along constant direction for making liquid crystal 115, the material that is used for alignment films that forms on the surface of separately substrate with cloth or analog polishing is to form alignment films 114 (grinding process).
Afterwards, be added on (draw on) TFT substrate by the encapsulant of distribution method (dispenser method), liquid crystal 115 be filled in by the sealer area surrounded by utilizing drippage (dropping) technology to inject liquid crystal with the ultraviolet curing type.Although in this example, introduced in this embodiment on TFT substrate 100 and formed sealer, liquid crystal 115 is filled in by in the sealer area surrounded, this method is not limited to this example, can on reverse side substrate 300, form sealer, liquid crystal 115 can be filled in by in the sealer area surrounded.
Then,, therein, filled liquid crystal 115 with reverse side substrate 300 and the 100 overlapping placements of TFT substrate, and with ultraviolet ray from the negative substrate 300 1 sides shine hermetic unit, to solidify sealer.
Afterwards, will adhere to polarizer according to following mode adds glass substrate on the plastic 301 and adds plastic 301 from polarizer and remove.Promptly, add under the situation of plastic 301 glass substrate being fixed to polarizer by bonding agent, according to the mode that the end of the end of glass substrate and plastic is separated along mutually opposite direction glass substrate is added the plastic 301 from polarizer and to remove, in described mode, its operation is similar to the operation of seeing in peeling off glass paper tape and sealer.On the other hand, add under the situation on the plastic 301 glass substrate being fixed to polarizer by negative-pressure adsorption, glass substrate and plastic 301 are separated from each other out by negative pressure being destroyed to air pressure according to nondestructive mode.Afterwards, will substrate that constitute be divided into the substrate of specific size by TFT substrate 100 and reverse side substrate 300 is bonding mutually, and polarizer 116 that is used for the TFT substrate and the polarizer 216 that is used for the reverse side substrate are adhered to two apparent surfaces of substrate respectively, thereby finished the formation of liquid crystal panel.Note, behind the surface of cleaning glass substrate, can utilize again to add the glass substrate of taking off the plastic from polarizer according to nondestructive mode.In the case, use alcohol or petroleum base organic solvent to remove bonding agent or the analog that adheres to glass substrate.
Equally, in this embodiment, the amount of deflection that can prevent glass substrate is to making the negative effect of liquid crystal panel, thus allow with handle the same procedure place polarizer that polarizer adds glass substrate and add the reason plastic.
As so far described, according to the method for making liquid crystal indicator of the present invention, form TFT and colored filter on the glass substrate in the active matrix substrate, add plastic lining as the polarizer in the reverse side substrate of substrate and form public electrode on the ground adopting polarizer to add plastic.In the case, use polarizer to add plastic is finished the formation of reverse side electrode as the reverse side lining ground of liquid crystal panel manufacturing step according to being used to, from adding step that plastic forms public electrode at polarizer to 200 cuttings of reverse side substrate and the step before being divided into the step of liquid crystal panel unit, glass substrate is adhered to polarizer add plastic, add the support substrates of plastic as polarizer.Therefore, can prevent that polarizer from adding the negative effect of the amount of deflection of plastic to the manufacturing liquid crystal panel, thereby allow to add plastic to handle polarizer with the same procedure of handling glass substrate.