CN1864096A

CN1864096A - Process for producing liquid crystal display panel

Info

Publication number: CN1864096A
Application number: CNA2004800293454A
Authority: CN
Inventors: 森本光昭
Original assignee: Sharp Corp
Current assignee: Sharp Corp
Priority date: 2003-10-08
Filing date: 2004-09-15
Publication date: 2006-11-15
Also published as: WO2005036247A1; JPWO2005036247A1; KR20060085935A; TWI268389B; TW200513758A

Abstract

A process for producing a liquid crystal display panel, comprising the sealant arranging step of disposing sealant (2) on a main surface of either one or both of two substrates to be bonded together, the liquid crystal dropping step of dropping liquid crystal (3) on either one (10) of the two substrates and the bonding step of bonging the two substrates (1,10) together, wherein the bonding step includes the hardening step of spreading the liquid crystal (3) interposed between the two substrates (1,10) until coming into contact with the sealant (2) along substantially the entire circumference of the sealant (2) while the two substrates (1,10) are both in contact with the sealant (2) along the entire circumference of the sealant (2) and thereafter hardening the sealant (2).

Description

The manufacture method of display panels

Technical field

The present invention relates to a kind of method of utilizing drippage and applying method to make display panels.Promptly, the present invention relates to a kind of manufacture method of display panels, this manufacture method may further comprise the steps: be coated with sealant at least one first type surface in two substrates that will be fitted in together, and dropping liquid crystal in two substrates, and with two baseplate-laminatings together.

Background technology

When making display panels, must be with two glass substrates that respectively have transparency electrode, thin film transistor (TFT) array or place its lip-deep like in advance, very little gap with about a few μ m is arranged relative to one another, two glass substrates are fitted mutually with sealant, filling liquid crystal in the gap, and carry out sealing.When big glass substrate (being also referred to as " female glass substrate ") was used as the material of substrate, below Shuo Ming method had been used for filling liquid crystal and sealing.

At first, under atmospheric pressure environments, on female glass substrate, arrange a plurality of seal patterns.On the surface of a female glass substrate, along the circumference coating sealant in the zone that will become liquid crystal cells.Sealant is applied to have the pattern of " inlet " with formation, just has the pattern that is used for liquid crystal is injected into the opening of liquid crystal cells, rather than the annular patterns of complete closed.Under this state, two female glass substrates are fit together, and carry out and to push and harden.Two female glass substrates of fitting mutually and fixing are called as " substrate of applying ".Subsequently, the substrate of applying is cut into the substrate of given size that the end is furnished with the inlet of each pattern, to obtain empty liquid crystal cells.The empty liquid crystal cells that as above obtains is used traditional liquid crystal implantttion technique injecting liquid crystal from inlet, and seal this inlet subsequently.

In the method for aforesaid filling liquid crystal, must carry out the step that two female glass substrates are fit together and the step of filling liquid crystal respectively.

As a comparison, as being the technology of pointing out in the Jap.P. (patent documentation 1) of 63-179323 and the Jap.P. (patent documentation 2) that publication number is 11-109388 at publication number, be suggested as the method that can carry out these two steps simultaneously.In in these technology each, liquid crystal is dropped on the surface of the substrate that is formed with seal pattern on it, and after this, two substrates are fitted in together under vacuum state, with the applying of carrying out substrate simultaneously and the filling of liquid crystal.More specifically, sealant is painted on in two substrates that will be fitted under vacuum state together one, and liquid crystal is dropped in the substrate one, and these two substrates are fitted in together.

Patent documentation 1: publication number is the Jap.P. of 63-179323

Patent documentation 2: publication number is the Jap.P. of 11-109388

Summary of the invention

The problem that the present invention solves

Comprise following problems at drippage under vacuum state described in the above-mentioned document and the method for fitting.

In patent documentation 1, liquid crystal is dropped on the multiple spot with rectangular form, so that make liquid crystal diffusion that is positioned on the substrate and the inner surface that roughly arrives each limit of sealant simultaneously.In this display panels pointed in first embodiment as patent documentation 1 is possible, and this display panels has the printed dimensions of sealing with at least 7 inches the corresponding 180mm * 80mm of Diagonal Dimension.Yet, in the little LCD screen of the Diagonal Dimension that is used for widely used in recent years mobile phone or digital camera with 1-2.4 inch, because it seals printed dimensions and approximately 22mm * 17mm to 50mm * 40mm is the same little, so with regard to the accuracy of guaranteeing to drip necessary pitch time and drainage, wish one or two dropping liquid crystalline substances are dropped onto each place, unit.In the case, be difficult to carry out to the multiple spot drippage, and, because seal pattern itself is little,, always roughly do not arrive the inner surface on each limit simultaneously with one or two liquid crystal that drip and spread the inner surface that arrives each limit of sealant.As a result, the thickness of liquid crystal of injection (after this being called " element thickness ") may become inhomogeneous, or liquid crystal may not be diffused on the total inner surface of seal pattern and may leave the gap,, may generate so-called " bubbles of vacuum " that is.

In addition, in an embodiment of patent documentation 2, before the liquid crystal contact sealant of diffusion, use ultraviolet ray or visible light sclerosis sealant.This also may cause uneven element thickness or generate bubbles of vacuum.Aforesaid problem becomes more serious in the area with respect to the viewing area has the small screen of printing length of relatively long sealant.

In view of aforesaid traditional problem, the present invention is proposed.A target of the present invention provides a kind of manufacture method of display panels, and this manufacture method can realize even element thickness and not have the state of bubbles of vacuum in the method for utilizing drippage and applying system manufacturing display panels.

The method of dealing with problems

In order to reach above-mentioned target, may further comprise the steps according to the manufacture method of display panels of the present invention: be coated with sealant at least one first type surface in two substrates that will be fitted in together; Dropping liquid crystal on one in two substrates; And together with two baseplate-laminatings, when the step of wherein fitting is included in two substrates all along the whole circumference contact sealant of sealant, diffuse into after the roughly whole circumference contact sealant of sealant the step of sclerosis sealant being sandwiched in two blocks of liquid crystal between the substrate.By adopting the method, since in the diffusion of roughly having finished liquid crystal and sealant roughly to obtain final thickness, and when element thickness became roughly evenly on whole zone, the sclerosis sealant was so can realize even element thickness easily and not have the state of bubbles of vacuum.

In foregoing invention, the applying step preferably includes at two substrates during all along the whole circumference contact sealant of sealant, diffuses into after the whole circumference contact sealant of sealant the step of sclerosis sealant being sandwiched in two blocks of liquid crystal between the substrate.By adopting the method, liquid crystal is diffused into each corner of liquid crystal cells, and element thickness becomes stable more reliably, and becomes even in whole unit.Therefore, can realize even element thickness and do not have the state of bubbles of vacuum more reliably.

In foregoing invention, sealant is preferably UV cured sealant, and cure step comprises the step with ultraviolet ray irradiation sealant.By adopting the method, can make display panels by easy steps sclerosis sealant with the ultraviolet ray irradiation.

In foregoing invention, sealant is preferably UV cured and the thermmohardening sealant, and cure step comprises with the interim cure step of ultraviolet ray irradiation sealant and the main cure step of heated sealant agent.By adopting the method, can make display panels by shining with ultraviolet ray and heating this two steps sclerosis sealants.At this moment, compare, can reduce ultraviolet irradiation amount with the situation of only finishing sclerosis with ultraviolet irradiation.

Effect of the present invention

According to the present invention, owing to after the diffusion of roughly finishing liquid crystal and sealant, carrying out cure step, so sclerosis becomes stable and evenly back execution at element thickness.Therefore, the display panels that can obtain having even element thickness and not comprise bubbles of vacuum.

Description of drawings

Fig. 1 is for going up the planimetric map that drafting has female glass of a large amount of seal patterns according in the first embodiment of the present invention its.

Fig. 2 is planimetric map and the cross-sectional view strength that is used to illustrate firm applying state afterwards, and this applying step is a step according to the manufacture method of the display panels in the first embodiment of the present invention.

Fig. 3 is used to illustrate that this step to the atmosphere opening vacuum chamber is a step according to the manufacture method of the display panels in the first embodiment of the present invention from begin the planimetric map and the cross-sectional view strength of the state of process after about 20 seconds to the atmosphere opening vacuum chamber.

Fig. 4 is planimetric map and the cross-sectional view strength that is used to illustrate the state when thickness that liquid crystal diffuses into the roughly whole zone that covers in the seal pattern and sealant becomes even, and this is a step according to the manufacture method of the display panels in the first embodiment of the present invention.

The explanation of Reference numeral

1:(is used for a side of printing and sealing agent) female glass, 2: seal pattern, 3: liquid crystal, 10:(are used for a side of dropping liquid crystal) female glass, 21,22,23, the 24:(seal pattern) limit

Embodiment

As mentioned above, element thickness is the thickness of the layer of filling liquid crystal.We can say that also element thickness is the thickness of the inner space of liquid crystal cells." liquid crystal cells " refers to be used to hold the space of the liquid crystal that is surrounded by two substrates of upper and lower sides and sealant, or is used to hold the space of the container-like structure of formation like this.

The result that the reason of the problem as mentioned above that takes place when using the technology of

patent documentation

1 and 2 as the inventor makes great efforts to study makes to draw a conclusion.

The thickness of liquid crystal cells is determined by following process.At first, in the applying process, sealant spreads by the pressure that is added on upper and lower base plate, that is, by the mechanical pressure from laminating apparatus, spread by the pressure differential between the outer atmospheric pressure of the vacuum space in the liquid crystal cells and liquid crystal cells etc.Liquid crystal in the liquid crystal cells is diffusion simultaneously also.In this case, when the inner surface of sealant did not contact liquid crystal, each limit of sealant was to spread with constant speed about equally.Yet when the inner surface of sealant contacted liquid crystal at any part place of the annular seal agent that forms liquid crystal cells, sealant and liquid crystal pushed mutually in this part.As a result, the rate of diffusion of the sealant that produces by the pressure that is added on upper and lower base plate only is reduced in this part.

On the other hand, still do not contact in the part of liquid crystal at the inner surface of sealant, because sealant continues diffusion by the pressure that is added on upper and lower base plate, its thickness is temporarily little than the thickness of the part with the sealant inner surface that contacts liquid crystal.

After this, the thickness of sealant stops to reduce when being reduced to the thickness of hermetic unit spacer.The hermetic unit spacer be blended in the sealant or be formed on spacer on the substrate by method such as photolithography.On the other hand, in lcd segment, the thickness of liquid crystal stops to reduce when being reduced to the thickness of unit internal partition.The unit internal partition be distributed on the substrate or be formed on spacer on the substrate by method such as photolithography.

Subsequently, when liquid crystal diffuses into the roughly whole circumference of contact sealant inner surface, in the part of sealant inner surface with previous contact liquid crystal, the thickness of sealant also is reduced to the thickness of hermetic unit spacer, and the thickness of lcd segment is reduced to the thickness of unit internal partition, although compare with other parts thickness reduce be delayed.

In this case, when the sclerosis of beginning sealant before the roughly whole circumference of liquid crystal contact sealant inner surface, the sealant that has in the part of sealant inner surface of previous contact liquid crystal is hardened with big thickness.This can cause the inhomogeneous of the element thickness that takes place in the process of the technology of using patent documentation 1 and 2.In addition, when becoming the part to have big thickness hardening seal, can produce and have the part that is fixed as greater than the element thickness of the value of desired value, and the capacity of liquid crystal cells can become greater than expectation value.As a result, it is not enough that liquid crystal becomes, and produce bubbles of vacuum.This may be the reason that produces bubbles of vacuum in the process of the technology of using

patent documentation

1 and 2.

In addition, when beginning the sclerosis of sealant before the roughly whole circumference of the inner surface that contacts sealant at liquid crystal, owing in the diffusion process of liquid crystal, carry out sclerosis, so the cell gap of sealant in the viewing area hardened during still greater than the end value that will reach.Therefore, the distance between the glass substrate near the part place of sealant with different at the place, viewing area, and be fixed under the residual state that distortional stress arranged between near the part of sealant and viewing area.This also can cause the inhomogeneous of element thickness.

The inventor finds, if in the cure step in being included in the applying step, at two substrates during all along the whole circumference contact sealant of sealant, diffuse into after the roughly whole circumference contact sealant of sealant being sandwiched in two blocks of liquid crystal between the substrate, the sclerosis sealant then can address these problems.Find that in order to verify this inventor has carried out experiment as described below.

(first embodiment)

(structure)

Now manufacture method according to the display panels in the first embodiment of the present invention is described with reference to Fig. 1-4 (a) and (b).Fig. 1 illustrates has 620mm * female glass 1 of 750mm size, draw the pattern (after this being called " seal pattern ") 2 that sealant is arranged on it, these patterns are with corresponding by 14 row * 20 capable 280 unit that form of the panel that has 1.5 inches Diagonal Dimension separately.It should be noted that " 1.5 inches Diagonal Dimension " represent a kind of standard, it is meant that when finishing display panels the profile that comprises the zone of liquid crystal has 1.5 inches diagonal line.

Seal pattern 2 has the shape that is roughly rectangle, its long limit be 21,22 and minor face be 23,24.The inside dimensions of seal pattern 2 is about 32mm * 24mm.Averaging unit thickness after the applying is 4.25 μ m, although thickness is inner and inhomogeneous in the unit.The liquid crystal of drippage has the density of 1.01g/cm3, and drips the liquid crystal of about 3.3mg in every unit.

Fig. 2-4 demonstrates the liquid crystal in the liquid crystal cells in the applying step in the manufacture method that is included in the display panels in this enforcement and the diffusion way of sealant., prepared to be printed with on it female glass 1 of seal pattern 2 and female glass 10 relative herein, liquid crystal drop has been dropped on the surface of female glass 10, and subsequently female glass 1 has been overlayed on female glass 10 to carry out applying with it.Consider the pitch time that is used for substrate, in each unit, liquid crystal drop is dropped on a bit.

Fig. 2 (a) and (b) illustrate the state after the firm applying.Be fitted in the vacuum chamber and be performed, and also not to the atmosphere opening vacuum chamber.The not a large amount of diffusions of liquid crystal 3.

Fig. 3 (a) and (b) illustrate the state after begin through 20 seconds to the atmosphere opening vacuum chamber.As the result of liquid crystal 3 diffusions, although liquid crystal 3 contacts with each limit on the limit respect to one another 21,22 with 24mm width, liquid crystal 3 does not still contact each limit on the limit respect to one another 23,24 with 36mm width.In this case, because sealant and liquid crystal 3 mutual extrusion, the rate of diffusion of sealant is reduced at each place, limit on the

limit

21,22 of seal pattern 2, and this causes herein thickness greater than the thickness at each place, limit on

limit

23,24.

Fig. 4 (a) and (b) illustrate following state: liquid crystal 3 is gone back

contact edge

23,24 except that

contact edge

21,22, and diffuses into the roughly whole zone that covers in the seal pattern 2, and the thickness of sealant becomes even.

Result as the inventor observes reaches the state shown in Fig. 4 (a) and (b), need be from begin the second through 40-50 to the atmosphere opening vacuum chamber after applying.

In this embodiment, after the applying of substrate after begin through 90 seconds to the atmosphere opening vacuum chamber, the step of the sealant that begins to harden.

(function and effect)

According to present embodiment, can obtain the display panels that has even element thickness and do not contain bubbles of vacuum.

When UV cured sealant is used as sealant, in cure step, can carry out step with ultraviolet ray irradiation sealant.

When UV cured and thermmohardening sealant are used as sealant, in cure step, can comprise with the interim cure step of ultraviolet ray irradiation sealant and the main cure step of heated sealant agent.

Emphasis is, when the applying step is included in two blocks of

female glass

1,10 all along the whole circumference contact sealant of seal pattern 2, diffuse into after the roughly whole circumference contact sealant of seal pattern 2 step of sclerosis sealant being sandwiched in two blocks of liquid crystal 3 between female glass 1,10.Preferably, in the case term " along whole circumference roughly " is replaced to " along whole circumference ".

When liquid crystal during along whole circumference contact sealant roughly, the diffusion of liquid crystal and sealant is roughly finished to reach final thickness or near the thickness of final thickness.When under this state, carrying out the sclerosis of sealant, can think that element thickness is stable.When liquid crystal during fully along whole circumference contact sealant, element thickness can become stable more reliably, and becomes even in whole unit.Therefore, be preferably in the sclerosis of carrying out sealant when reaching as above state.

When above-mentioned patent documentation 2 is mentioned before the sclerosis sealant liquid crystal contact sealant, the problem of the liquid crystal deterioration that causes in the liquid crystal owing to the composition stripping of sealant.Yet, compare with the time of patent documentation 2 application, technology has obtained progress in recent years, does not make the sealant of liquid crystal deterioration when having developed before sclerosis contact liquid crystal.That is, prerequisite is different from the application time of patent documentation 2 to a great extent.When realizing when of the present invention, can suitably select and use the sealant that does not make the liquid crystal deterioration when before sclerosis, contacting liquid crystal, to avoid the deterioration of liquid crystal.

The example on having pointed out only liquid crystal drop to be dropped in each unit a bit in the present embodiment it should be noted, although when execution drops on liquid crystal drop operation on the multiple spot in each unit, also can be used the present invention.

It should be noted, although in the present embodiment, be used for dropping liquid crystal a side substrate and to be used for the substrate of a side of printing and sealing agent different, also can carry out the printing of sealant and the drippage of liquid crystal at the substrate of the same side of from two substrates, selecting.Alternatively, only carry out the drippage of liquid crystal in substrate, and can on two substrates, all carry out the printing of sealant.

Embodiment disclosed herein is illustrative in all main points, rather than restrictive.It is specified that scope of the present invention be can't help above-mentioned explanation, but specified by the scope of claims, and comprise connotation that the scope with claims is equal to and all changes in the scope.

Industrial usability

The present invention can be applicable to make by drippage and applying method the method for display panels.

Claims

1. the manufacture method of a display panels, it may further comprise the steps:

Be coated with sealant (2) at least one first type surface in two substrates (1,10) that will be fitted in together;

Dropping liquid crystal (3) is gone up in (10) in described two substrates; With

Described two substrates (1,10) are fit together; Wherein,

Described applying step is included in described two substrates (1,10) all when the whole circumference of described sealant (2) contacts described sealant (2), diffuse into along the roughly whole circumference of described sealant (2) and contact described sealant (2) afterwards, the step of described sealant (2) of hardening being sandwiched in described liquid crystal (3) between described two substrates (1,10).

2. the manufacture method of display panels as claimed in claim 1 is characterized in that

Described applying step is included in described two substrates (1,10) all when the whole circumference of described sealant (2) contacts described sealant (2), diffuse into along the whole circumference of described sealant (2) and contact described sealant (2) afterwards, the step of described sealant (2) of hardening being sandwiched in described liquid crystal (3) between described two substrates (1,10).

3. the manufacture method of display panels as claimed in claim 1 is characterized in that

Described sealant (2) is UV cured sealant, and described cure step comprises the step with the ultraviolet ray described sealant of irradiation (2).

4. the manufacture method of display panels as claimed in claim 1 is characterized in that

Described sealant (2) is UV cured and the thermmohardening sealant, and described cure step comprises the main cure step of shining the interim cure step of described sealant and heating described sealant with ultraviolet.