KR101584995B1 - Method for Forming Color Filter Array of Flat Panel Display and Baking Apparatus for Being Applied in this field - Google Patents

Abstract

The present invention relates to a method of forming a color filter array of a flat panel display device in which a firing step is performed in a short time during the formation of a color filter and a firing equipment used therefor. In a method of forming a color filter array of a flat panel display device of the present invention, Jetting red ink, green ink, and blue ink through a nozzle simultaneously corresponding to different pixel regions on a substrate including the black matrix layer, and forming a black matrix layer And successively soft baking and hard baking the red, green and blue inks through a sintering machine including an infrared plate heater.

Color filter arrays, firing equipment, infrared plate heaters, soft baking, hard baking,

Description

TECHNICAL FIELD [0001] The present invention relates to a method of forming a color filter array of a flat panel display device,

The present invention relates to a flat panel display, and more particularly, to a method of forming a color filter array in which a firing process is performed in a short time during formation of a color filter, and a firing equipment used therein.

In recent information society, display has become more important as a visual information delivery medium, and it is necessary to meet requirements such as low power consumption, thinning, light weight, and high image quality in order to take a major position in the future.

Such a display may include a cathode ray tube (CRT), an electroluminescence (EL), a light emitting diode (LED), a vacuum fluorescent display (VFD) A light emitting type such as a field emission display (FED), a plasma display panel (PDP) or the like, and a non-light emitting type such as a liquid crystal display (LCD) .

Among them, the liquid crystal display device is an apparatus for expressing an image using the optical anisotropy of liquid crystal, which is superior in visibility compared to a conventional CRT and has a smaller average power consumption than a CRT of the same screen size, Panel or field emission display, has recently been attracting attention as a next-generation display device.

In general, a liquid crystal display device is a display device that can display a desired image by individually supplying image signals to pixels arranged in a matrix form, and adjusting the light transmittance of the pixels. To this end, the liquid crystal display device has a structure in which a lower substrate on which thin film transistors are arranged and an upper substrate on which color filters are formed are bonded together with the liquid crystal layer interposed therebetween. In addition, a polarizing plate is formed on the surfaces of the lower substrate and the upper substrate, respectively, to control blocking or transmission along the transmission direction.

Here, an alignment layer is formed on the uppermost layer of the lower substrate and the upper substrate, and the initial alignment direction of the liquid crystal is determined by the alignment layers.

The process of manufacturing one liquid crystal display panel by attaching the upper substrate and the lower substrate together is referred to as a cell process. The cell process includes an alignment process for forming an alignment layer for aligning the liquid crystal in one direction on a lower substrate on which thin film transistors are arranged and an upper substrate on which a color filter is formed and a process for aligning two substrates to maintain a certain cell gap A bonding step of injecting liquid crystal between the upper and lower substrates on which the laminating process has been performed, and a cell cutting step of separating the liquid crystal display panel unit are performed.

Then, upper and lower polarizers are attached to the front and back surfaces of the liquid crystal display panel, respectively.

Hereinafter, a method of forming a color filter array of a conventional liquid crystal display device will be described with reference to the accompanying drawings.

1 is a process flow chart showing a conventional color filter layer manufacturing process.

First, a black matrix (not shown) for blocking light leakage between the pixel regions is formed on a substrate (not shown) defining a plurality of pixel regions spaced from each other.

Subsequently, the substrate on which the black matrix is formed is washed (10S).

Next, a photoresist of a liquid red color filter (R) is coated on the substrate including the black matrix (11S).

Subsequently, the substrate is introduced into a vacuum chamber (VCD) for drying the solvent contained in the photoresist (12S). The reason why the substrate is placed in the vacuum drying chamber is that if the content of the solvent contained in the liquid photoresist is large and the substrate is dried only by heat, it is impossible to avoid surface unevenness. Therefore, It is for the purpose of the process.

Subsequently, the substrate including the primarily dried photoresist is placed in an oven, and heat is first applied to perform soft baking (13S).

Subsequently, the photoresist subjected to the soft baking is exposed (14S), and a developing (15S) process is performed to remove the exposed region or the unexposed region to form a red color filter layer. Here, the photoresist is a positive photoresist if the exposed portion is removed by the exposure and development process, and the negative photoresist if the exposed portion remains, and the shape of the mask used in the exposure process is different according to the corresponding photosensitivity of the photoresist .

Subsequently, the substrate including the developed red color filter layer is placed in an oven, and hard baking is performed (16S) to heat the second color filter layer completely to volatilize the solvent component.

Next, pattern inspection of the formed red color filter layer is performed (17S). If an abnormality or defect occurs in such a pattern inspection process, a rework process may be performed in which a formed color filter layer is removed and then a color filter layer is newly formed again.

In addition to the formation of the red color filter layer described above, the steps of 10S to 17S described above must be performed in the same manner as the formation process of the green and blue color filter layers.

Also, an overcoat layer (not shown) and / or a common electrode (not shown) are formed on the thus formed red, green, and blue color filter layers.

In this way, the photo-lithography color filter manufacturing process, separately forming a color filter layer of each color, soft baking and hard baking processes are carried out through the oven in a thermal convection mode In this case, gas which becomes a convection medium must be used, and it takes a considerable time to raise the substrate up to a certain temperature.

The conventional method of forming a color filter array has the following problems.

In forming a color filter array, a soft baking and hard baking process must be applied separately to form a color filter layer of each color, in addition to exposure and development, to cure the color filter. Therefore, the order of the processes is large and troublesome.

In the orderly photolithography method, the hard baking process proceeds after the development, and the soft baking and hard baking baking processes can not proceed continuously. Therefore, the oven inflow / outflow process must be repeated for each baking process, Simplification of the process was impossible.

In addition, it is necessary to cool the photoresist after the soft baking to lower the temperature of the partially dried photoresist before exposure, so that the application of heat does not constantly proceed in the temperature increasing direction, Baking takes longer to heat up.

In addition, in the case of hard baking conducted in a tropical-type manner, it is difficult to raise the temperature in a short period of time, so that the hard baking process takes a long time. For example, it took at least 25 minutes to raise the temperature to 220 ° C or higher for hard baking in the case of using the hot water type.

In order to solve the problems of such a photolithography method, there has been an attempt to make the color filter array process an ink-jet process. In this case, too, a cooling process for cooling the substrate after the soft- , The process was not simplified and the process time was not reduced.

It is an object of the present invention to provide a method of forming a color filter array of a flat panel display device and a firing apparatus to be used in the method, in which a firing process is performed in a short time during formation of a color filter.

According to another aspect of the present invention, there is provided a method of forming a color filter array of a flat panel display, including: forming a black matrix layer on a substrate to divide pixel regions; Jetting red ink, green ink, and blue ink through the nozzles simultaneously corresponding to different pixel regions; And continuously soft-baking and hard baking the jetted red, green and blue inks through a firing equipment including an infrared plate heater.

And after the black matrix layer is formed, cleaning the substrate.

The soft baking and hard baking may include a step of raising the temperature of the substrate from 100 to 130 DEG C at a room temperature, maintaining the temperature of the first heating of the substrate, and soft-baking the red, Heating the substrate to a temperature ranging from 100 to 130 DEG C to 220 to 300 DEG C; And maintaining the temperature of the second heating of the substrate, and hard baking the red, green and blue inks to form a color filter layer.

The method may further include inspecting the substrate after completion of the soft baking and the hard baking.

In order to accomplish the same object, a firing apparatus of the present invention for achieving the same object comprises: a chamber provided with a plurality of heat treatment sections in the vertical direction as heat; Loading cassette; And an infrared plate heater on the lower side of each substrate loading cassette.

The method of forming a color filter array of the flat panel display device of the present invention and the firing equipment used therein have the following effects.

First, the color filter array is formed by an ink jet jetting method, and the red, green, and blue color filter layers are formed at the same time, and the process order and the process time can be reduced.

Second, the soft baking and the hard baking are performed by using the infrared plate heater which is easy to raise the temperature, so that the soft baking and the hard baking process can be performed with the same baking equipment.

Third, the hard baking process can be stably performed in a short time by the radiant heating method by using the infrared plate heater which has a rapid heating process.

Fourth, the soft baking process and the hard baking process are successively performed in one firing equipment, cooling process between the soft baking process and the hard baking process is eliminated, and the soft baking process and the hard baking process can be continuously performed in one firing equipment. have.

Hereinafter, a method of forming a color filter array of a flat panel display of the present invention and a firing apparatus used therein will be described in detail with reference to the accompanying drawings.

FIG. 2 is a flow chart showing a process of manufacturing a color filter layer of the present invention, and FIG. 3 is a view showing an inkjet process used in a color filter layer production process of the present invention.

3, the color filter layer manufacturing process of the present invention is a process for manufacturing a color filter layer 102a, 102b, and 102c (red, green, and blue) on a substrate 100 on which a black matrix layer 101, ) Are jetted by an inkjet apparatus to form red, green, and blue color filter layers. At this time, the red, green, and blue pigment inks 102a, 102b, and 102c are jetted at the same position through different nozzles 200 at the same time.

Referring to FIG. 2, the procedure of forming the color filter array substrate of the present invention will be described below.

First, a substrate 100 formed with a black matrix layer 101 (FIG. 3) is introduced through a process line 300, and then the substrate 100 is cleaned (100S), and the cleaned substrate 100 is red, green, The pigment ink is positioned so as to correspond to the nozzle 200 of the inkjet apparatus that supplies each.

The red, green, and blue pigmented inks 102a, 102b, and 102c are simultaneously jetted (110S: 101S, 102S, 103S) to the corresponding positions on the substrate 100 through the nozzles 200 of the inkjet apparatus.

At this time, the substrate 100 or the nozzles 200 are moved relative to each other, and the pigment inks 102a, 102b, and 102c of the corresponding colors are jetted in a stripe or a star shape (110S: 101S, 102S, 103S). Here, the red, green, and blue pigment inks 102a, 102b, and 102c have better viscosities and relatively smaller solvent contents than the color pigments patterned in the exposure and development processes, It is not necessary to enter the drying chamber.

Soft baking 105S and hard baking 106S are then carried out to dry the solvent in the jetted pigment inks 102a, 102b, 102c and to cure the bond with the polymer in the pigment ink, And then proceeds to a heat treatment step 120S. In this case, the heat treatment step 120S including the soft baking and hard baking is a process of heating and maintaining the heat in a firing device with time, and a temperature of about 100 to 130 DEG C is required for soft baking And a temperature of about 260 ± 20 ° C was required for hard baking.

In the case of the soft baking 105S and the hard baking 106S, the temperature must be maintained in a warmed state. In the pattern forming method of the flat panel display device of the present invention, in order to accelerate the temperature rise and increase the retention efficiency, Type Infrared Plate Heater is placed in the firing equipment, and the above-described soft baking 105S and hard baking 106S are continuously performed. In this case, the temperature at the time of the soft baking 105S is maintained immediately after the soft baking 105S without cooling, the temperature is raised to the temperature corresponding to the hard baking, and then the hard baking 106S is continued . In this case, the infrared plate heater is advantageous in that the glass substrate 100 is brought into contact with the glass substrate 100 through the pin in a radiant heating manner, thereby speeding up the temperature raising process.

Subsequently, the color filter layer made of the color filter pigment ink hardened by the above-described soft baking and hard baking is subjected to a pattern inspection (130S) for judging whether the color filter layer is defective or damaged and then subjected to a rework or a next process Or formation of a common electrode).

As described above, in the pattern forming method of the flat panel display of the present invention, the nozzles for jetting the pigment inks of different colors are corresponded to the regions on the substrate of the flat panel display by using the ink jet apparatus to form red, green and blue color pigment inks And simultaneously, the heat treatment process 120S is performed on the ink of each color of the jetted pigment.

In addition, all of the baking processes are performed by one firing equipment, and an infrared plate heater is provided in the furnace. The temperature of the baking process is rapidly increased. In the soft baking requiring a relatively high temperature, It is possible to raise the temperature within 100 to 120 seconds, and the temperature rise time is reduced to at least 1/8 level as compared with the conventional hot air type. In addition, the heating time is required to be 100 seconds or less when the temperature is raised by the soft baking process, and the temperature rise time at this time is also reduced compared to the hot air type.

Particularly, in the baking process of the photoresist according to the conventional photolithography method, a step of drying the vacuum drying chamber for a predetermined time and a separate exposure and development process are further required. However, in the case of forming the color filter array The vacuum drying process, exposure and development processes necessary for such a photolithography process can be omitted by forming a color filter using an inkjet apparatus.

Also, even if a soft baking process and a hard baking process, which require temperature conditions different from each other, are carried out after the exposure in the first baking of the vacuum-dried photoresist, there is no intervening cooling process, The sintering process can be performed without lowering the temperature of the substrate 100 by performing the sintering process of the temperature elevation type and the time for only the sintering process can be reduced due to the omission of the cooling process and the rapid temperature increase.

FIG. 4 is a graph showing control temperatures of the firing equipment of the present invention over time. FIG.

FIG. 4 illustrates a temperature raising process during the baking process according to an exemplary embodiment, and is an example used in a large-area 8th generation inkjet process equipment.

As shown in FIG. 4, in the case of using the firing apparatus of the present invention, the temperature for the soft baking was raised by elevating the substrate introduced into the firing equipment from room temperature (25 ° C.) to 110 ° C. within about 85 seconds, And the soft baking process is carried out so as to evaporate the solvent of the color ink pigment sufficiently jetted for a predetermined time.

The temperature of the substrate was raised from 110 ° C to 260 ° C without a cooling process. The temperature of the substrate was elevated uniformly through the infrared plate heater of the sintering equipment to raise the temperature within about 115 seconds.

As an example of the above embodiment, the temperature at the time of soft baking is in the range of 100 to 130 ° C, and the hard baking is possible in the range of 220 to 300 ° C.

Hereinafter, the firing equipment of the present invention will be described with reference to the drawings.

FIG. 5 is a plan view showing a firing apparatus in which a baking process is performed after the ink-jet process of the present invention, and FIG. 6 is a perspective view of the firing apparatus of FIG.

5 and 6, the firing equipment of the present invention includes a chamber 450 having an internal space therein, a plurality of heat treatment units (shown in FIG. 6) configured in parallel in a vertical direction within the chamber 450, The first to third heat treatment units). A substrate loading cassette 400 in which a glass substrate flows in from the outside to the inside of the apparatus and flows in and out from the inside and outside of the apparatus in a heat treatment unit of each heat treatment unit and a substrate loading cassette 400 An infrared plate heater 410 positioned at a lower side of the cassette 400 and radiating heat radiated from the substrate into the substrate loading cassette 400 at a lower side of the cassette 400; And a moving rail 420 for taking in / out of the movable rail 400.

The lower side of the drawer type substrate loading cassette 400 is opened so that the infrared plate heater 410 can contact the substrate loaded in the cassette 400 via the pins, And a lower surface of the infrared ray plate heater 400 may be constituted by an infrared ray plate heater 410.

The infrared plate heater 410 is a plate-shaped heater which is heated to a high temperature and radiates high-power infrared rays. The body of the infrared plate heater 410 is heated by electric energy supplied from the outside, (Not shown), and a heat insulating material installed to surround the outer periphery of the heat generating body to prevent unnecessary loss of heat. In addition, a structural member for enhancing the radiation efficiency of infrared rays, a structural strength of the infrared heat- A reinforcing member for fixing the heating element, a fixing member, and the like.

In other words, the apparatus of the present invention has the infrared plate heater 410 which is in contact with the substrate via the fin, so that the heat transfer is performed by the radiant heating method, so that the temperature is raised quickly and the temperature is maintained easily.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Will be apparent to those of ordinary skill in the art.

1 is a flowchart showing a conventional color filter layer manufacturing process.

2 is a flowchart showing a process of manufacturing a color filter layer of the present invention

3 is a view showing an inkjet process used in the color filter layer manufacturing process of the present invention

4 is a graph showing the control temperature over time of the firing equipment of the present invention

5 is a plan view showing a firing apparatus in which a baking process is performed after the inkjet process of the present invention

FIG. 6 is a perspective view showing the firing equipment of FIG.

Description of the Related Art [0002]

100: substrate 101: black matrix layer

102a, 102b, 102c: color pigment ink 200: ink jet nozzle

300: process line 400: substrate loading cassette

410: Infrared plate heater 420: Moving rail

450: chamber

Claims (6)

Forming a black matrix layer on the substrate to separate the pixel regions; Jetting red ink, green ink, and blue ink through the nozzles simultaneously corresponding to different pixel regions on the substrate including the black matrix layer; And Continuously soft baking and hard baking the jetted red, green and blue inks through a firing equipment including an infrared plate heater, Wherein the soft baking and hard baking comprises: Heating the substrate at a temperature of 100 to 130 DEG C at a room temperature; Maintaining the substrate at a first temperature elevation temperature, and soft baking the red, green and blue inks; Heating the substrate to a temperature of from 220 to 300 ° C at a temperature of from 100 to 130 ° C; And And maintaining the temperature of the second heating of the substrate and hard baking the red, green and blue inks to form a color filter layer. The method according to claim 1, Further comprising the step of cleaning the substrate after forming the black matrix layer. delete The method according to claim 1, The firing equipment includes: A chamber provided with a plurality of heat treatment sections in the vertical direction; A substrate loading cassette in each of the heat treatment units for taking in the substrate from the outside and taking the substrate out to the outside; And And an infrared plate heater below each of the substrate loading cassettes. 3. The method of claim 2, Further comprising inspecting the substrate after completion of the soft baking and hard baking. delete

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