Method of fabricating an apparatus of fabricating an flat panel display device and method for fabricating flat panel display device

A method of fabricating an apparatus of fabricating a flat panel display device and method of fabricating flat panel display device is disclosed, which enables simplification of process by performing a patterning process without a photo process, the method for fabricating an apparatus of fabricating flat panel display device comprising, preparing a master mold including a thin film pattern, coating a liquid-type molding material including oligomer on the master mold, forming a soft mold including a groove provided with a pattern in a shape corresponding to the thin film pattern of the master mold and adhering the soft mold to a mold support plate, wherein the soft mold is adhered to the mold support plate by a covalent bonding in the interface between the oligomer and the mold support plate.

CLAIM FOR PRIORITY

This application claims the benefit of Korean Patent Application No. 10-2006-12730 filed Dec. 4, 2007, which is hereby incorporated by reference as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a flat panel display device, and more particularly, to method for fabricating apparatus of fabricating flat panel display device and method for fabricating flat panel display device, which enables to carry out a patterning process without a photo process.

2. Discussion of the Related Art

In a recent information society, there is a great emphasis on display devices as visual information transmission medium. In case of cathode ray tubes CRTs which are used commonly in the recent information society, they have problems of high volume and weight. Examples of flat panel display devices are a liquid crystal display device LCD, a field emission display FED, a plasma display panel PDP, and an electroluminescence device EL, and the most of them have been put to practical use.

The LCD device can satisfy a recent trend in a marketing field of electronic device, that is, thin profile and light weight, and also can realize the mass production. In this respect, the LCD device substitutes for the CRT in wide application fields. Especially, an active-matrix type LCD device, which drives a liquid crystal cell by using a thin film transistor (hereinafter, referred to as “TFT”), has advantages of high picture quality and low power consumption. Owing to results of recently searched mass-production technology, the LCD device has been developed to large-size and high resolution device.

As shown inFIG. 1, the active-matrix type LCD device includes a color filter substrate22and a TFT array substrate23bonded to each other with a liquid crystal layer15formed therebetween. The active-matrix type LCD device shown inFIG. 1illustrates some of an entire effective screen.

The color filter substrate22includes a color filter13and a common electrode14formed on a rear surface of an upper glass substrate12. On the entire surface of the upper glass substrate12, the color filter13includes red(R), green(G) and blue(B) color filters which transmit light of corresponding wavelength bands, to thereby enable to display colors. Although not shown, a black matrix is positioned between each of the adjacent color filters13.

The TFT array substrate23includes a plurality of gate lines18and data lines19formed on an entire surface of a lower glass substrate16, wherein each gate line18is formed in perpendicular to each data line19. At this time, thin film transistors20are formed at every crossing of the gate and data lines18and19. On the entire surface of the lower glass substrate16, a pixel electrode21is formed in each cell region defined by the gate and data lines18and19. The thin film transistor20switches a data transmission pass between the data line19and the pixel electrode21in response to a scanning signal from the gate line18, to thereby drive the pixel electrode21. A polarizing plate17is attached to the rear surface of the TFT array substrate23. Also, the liquid crystal layer15controls the amount of incident light passing through the TFT array substrate23by an electric field applied.

The polarizing plates11and17attached to the color filter substrate22and the TFT array substrate23transmit the light polarized toward any one direction. When the liquid crystal layer15is in 90° TN mode, the polarizing directions of the polarizing plates11and17are perpendicular to each other. Although not shown, alignment films are formed on the liquid crystal facing surfaces of the color filter substrate22and the TFT array substrate23.

A process for fabricating the active-matrix type LCD device includes a substrate cleaning step, a substrate patterning step, an alignment film forming and rubbing step, a substrate bonding and liquid crystal injecting step, a mounting step, a test step, and a repair step. At this time, the substrate cleaning step removes foreign matters from the surface of substrate by using a cleaner. The substrate patterning step includes patterning the color filter substrate and patterning the TFT array substrate. The alignment film forming and rubbing step includes coating the alignment film on each of the color filter substrate and the TFT array substrate, and rubbing the coated alignment film by a rubbing cloth. The substrate bonding and liquid crystal injecting step includes bonding the color filter substrate and the TFT array substrate to each other by using a sealant, providing spacers between the two substrates, injecting liquid crystal to a space between the two substrates through an inlet, and sealing the inlet. The mounting step includes connecting a tape carrier package (hereinafter, referred to as “TCP”) on which a gate drive integrated circuit and a data drive integrated circuit are mounted to a pad region of the substrate. The drive integrated circuit may be directly mounted on the substrate by Chip On Glass (hereinafter, referred to as “COG”), instead of Tape Automated Bonding using the aforementioned TCP. The test step includes an electrical test performed after forming the pixel electrodes and signal lines such as the gate and data lines on the TFT array substrate, and an electrical test and macrography performed after the substrate bonding and liquid crystal injecting step. The repair step performs the repair for the substrate which is judged to be reparable by the test step. If it is impossible to repair the substrates, they are discarded.

When fabricating the various flat panel display devices as well as the LCD device, a thin film material deposited on a substrate is patterned by photolithography. The photolithography includes steps of photoresist coating, mask alignment, exposure, development and cleaning. However, the photolithography requires a long period of time, and causes the lost of photo-resist material and stripping liquid. Also, it is necessary for the photolithography to use a high-priced exposure apparatus.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an method for fabricating apparatus of fabricating flat panel display device and method for fabricating flat panel display device that substantially obviates one or more problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a method for fabricating apparatus of fabricating flat panel display device and method for fabricating flat panel display device, which enables simplification of process by performing a patterning process without a photo process.

Another object of the present invention is to provide a method for fabricating apparatus of fabricating flat panel display device and method for fabricating flat panel display device, which can simplify the process and reduce the fabrication cost.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a method for fabricating apparatus of fabricating flat panel display device comprises preparing a master mold including a thin film pattern; coating a liquid-type molding material including oligomer on the master mold; forming a soft mold including a groove provided with a pattern in a shape corresponding to the thin film pattern of the master mold; and adhering the soft mold to a mold support plate, wherein the soft mold is adhered to the mold support plate by a covalent bonding in the interface between the oligomer and the mold support plate.

DETAILED DESCRIPTION OF INVENTION

Hereinafter, an apparatus and method of fabricating a flat panel display device according to the preferred embodiment of the present invention will be explained with reference toFIGS. 2 to 10.

Referring toFIGS. 2 and 3, a method of fabricating a flat panel display device according to the preferred embodiment of the present invention can form a thin film pattern having a desired shape by using a soft mold134instead of a related art photoresist pattern process.

A thin film patterning process using the soft mold134includes steps of coating etch-resist liquid133aon a substrate131including a thin film132a; patterning an etch-resist layer by using the soft mold134; performing an etching for patterning of a thin film132; stripping remaining etch-resist pattern; and testing. To form the thin film132aon the substrate131, a basic material used for a metal pattern, an organic material pattern, and an inorganic material pattern included in an array of the flat panel display device is formed on the substrate131by coating or deposition.

The etch-resist liquid133aincludes a main resin of at least any one of liquid pre-polymer and liquid monomer, an activator, an initiator, and thermal flow derivatives. The etch-resist liquid133ais coated on the thin film132aby nozzle-spraying or spin-coating.

The soft mold134is formed of a rubber material of good elasticity, for example, polydimethylsiloxane PDMS, polyurethane, and cross-linked novolac resin. The soft mold134is provided with grooves134awhich correspond to patterns remaining on the substrate131. The soft mold134is provided with the grooves134aand protruding surfaces134b. Then, the surface of soft mold134is performed with hydrophilic or hydrophobic treatment. Hereinafter, a case using the hydrophobic soft mold134will be explained as follows.

After positioning the soft mold134above the etch-resist liquid133a, the soft mold134is put on the etch-resist liquid133a. Thus, the etch-resist liquid133ais pressurized at a pressure of enabling a contact with the thin film132a, that is, by a weight of the soft mold134.

For example, as shown inFIG. 3, the etch-resist liquid133amoves toward the inside of groove134aincluded in the soft mold134by a capillary force generated by a pressure between the soft mold134and the substrate131and a repulsive force between the soft mold134and the etch-resist liquid133a, thereby forming an etch-resist pattern133b, whose shape is inverted to the pattern of groove134aincluded in the soft mold134, on the thin film132a. After separating the soft mold134from the substrate131, a wet-etching or dry-etching is carried out. At this time, the etch-resist pattern133bfunctions as a mask. Thus, only predetermined portions of the thin film132apositioned under the etch-resist pattern133bremain on the substrate131, and the other exposed portions of the thin film132aare removed. Then, the etch-resist pattern134bis removed by stripping, and a test for the short and disconnection of the thin film pattern132bis performed through an optical test.

After separating the soft mold134from the substrate131, the substrate131is cleaned with UV and ozone O3, and then soft mold134is re-used in the process for patterning another thin film132a.

FIG. 4illustrates an apparatus and method of fabricating a flat panel display device according to the first embodiment of the present invention.

As shown inFIG. 4, a master mold184including a photoresist pattern, an inorganic material pattern and a thin film pattern182is prepared on a substrate180. Then, a molding material135including polydimethylsolixane PDMS and a small amount of curing agent is coated on the master mold184having the thin film pattern182. Thereafter, the liquid type molding material135is maintained at a room temperature (about 25° C.) for one hour to two days. In another method, the molding material135coated on the master mold184is treated by a thermal curing at a temperature of about 80° C. for one hour, thereby forming the soft mold134from which the master mold184is not separated.

The mold support plate143(or referred to as “backplane”)143coated with an adhesive145is prepared. After the mold support plate143adheres closely to the rear surface of the soft mold134from which the master mold184is not separated in state of positioning the adhesive145therebetween, they are maintained for one day (24 hours) to two days, thereby curing the adhesive145. By means of the adhesive145, the mold support plate143closely adheres to the rear surface of the soft mold134. At this time, the adhesive145may be formed of glycidyl methacrylate mixed with a photo-initiator such as Igarcure379, or may be formed of butyl methacrylate mixed with a photo-initiator such as Igarcure379.

As the soft mold134is separated from the master mold184, the soft mold134is completed with the grooves which are identical in shape to the thin film pattern182of the master mold184. At this time, the mold support plate143prevents the length of soft mold134from being decreased. Also, the mold support plate143serves as means of separating the soft mold134from the master mold184, and transmitting and stamping means for the soft mold134. The soft mold fabricated by the aforementioned process is used for forming the thin film pattern of the flat panel display device.

In the process ofFIG. 4, the soft mold134and the mold support plate143are bonded to each other by the adhesive145, thereby causing problems of increasing fabrication cost and time. Especially, the time of curing the adhesive143raises a problem of the increase of time to fabricate the entire soft mold134.

The second embodiment of the present invention proposes the technology for forming the soft mold134and the mold support plate143as one body without the use of adhesive. In case of the second embodiment of the present invention, the soft mold134is formed of PDMS polymer having a terminal group of Si—H into which a linear oligomer chain is inserted.

A chemical formula for the related art PDMS is (H3C)[SiO(CH3)2]nSi(CH3)3, and ‘n’ is the number of monomers [SiO(CH3)2]. PDMS has a structure where a base part and an X-linker part are bonded at a ratio of 10 to 1.

FIG. 5illustrates the polymer structure of the related art PDMS. Referring toFIG. 5, the base part A is configured with the monomers linked linearly, and the base part A corresponds to the polymer having the terminal group of Si—H. Also, the X-linker part B is configured with the monomers linked linearly, and the X-linker part B corresponds to the polymer having the monomers, some of which are partially bonded to hydrogen(H).FIG. 5illustrates a structural formula of [SiO(CH3)2] monomer201.

The material for the soft mold proposed by the present invention is formed by inserting oligomer having terminal group of Si—H into PDMS polymer ofFIG. 5. That is, as shown inFIG. 6, ten or less monomers [SiO(CH3)2] are polymerized to PDMS polymer comprised of the base part A and the X-linker part B, and the soft mold is formed by using the molding material to which the oligomer having the terminal group of Si—H is inserted. For example, the soft mold is configured that the base part A, the X-linker part B and the oligomer C are mixed at a ratio of 1:1:1. Through the use of the soft mold having the aforementioned structure, the soft mold134is adhered to the mold support plate143without the use of adhesive.

This will be explained with reference toFIG. 7.FIG. 7illustrates an apparatus and method of fabricating a flat panel display device according to the second embodiment of the present invention.

First, a master mold184including a photoresist pattern, an inorganic material pattern and a thin film pattern182is prepared on a substrate180. After that, a molding material135is coated on the master mold184including the thin film pattern182, wherein the molding material135is formed by adding oligomer having a terminal group of Si—H to PDMS comprised of a base part A and an X-linker part B.

Thereafter, the liquid type molding material135is maintained at a room temperature (about 25° C.) for one hour to two days. In another method, the molding material135coated on the master mold184is treated by a thermal curing at a temperature of about 80° C. for one hour, thereby forming the soft mold134from which the master mold184is not separated.

After preparing a mold support plate143, the mold support plate143adheres closely to the rear surface of the soft mold134which is not separated from the master mold184, and a heat treatment of 80° C. to 100° C. is performed at a period of 5 minutes to 20 minutes. Thus, there is the strong covalent bonding between the interface of mold support plate143corresponding to a glass substrate and the oligomer C of the soft mold134.

FIG. 8illustrates the covalent bonding between the oligomer C and the interface of mold support plate143. Referring toFIG. 8, the mold support plate143is configured that hydroxyl radical (OH) is positioned in the interface of mold support plate143and Si—H is positioned in the terminal group of oligomer C. Accordingly, there is the strong covalent bonding between hydroxyl radical (OH) and H(hydrogen) at the terminal group of oligomer C, or between H(hydrogen) of hydroxyl radical (OH) and H(hydrogen) at the terminal group of oligomer C. As a result, the soft mold134is adhered to the mold support plate143without an additional adhesive.

An applicant of the present invention checks the adhesive strength between the soft mold134and the mold support plate143through the following experimental results ofFIG. 9. The applicant performs the experiment to forcibly separate the soft mold134from the mold support plate143by using a holder252after loading the mold support plate143having the soft mold134being adhered thereto on a vacuum stage250. On assumption that the soft mold134is adhered to the mold support plate143by using the related art adhesive, the soft mold134and the mold support plate143are separated from each other when a vacuum level of 10−2torr and a speed level of 0.01 mm/s are applied to the vacuum stage250having the soft mold134and the mold support plate143loaded thereon. Meanwhile, on assumption that the soft mold134is adhered to the mold support plate143by the covalent bonding proposed in the second embodiment of the present invention, the soft mold134and the mold support plate143are not separated from each other even though a vacuum level of 10−2torr and a speed level of 0.01 mm/s are applied to the vacuum stage250having the soft mold134and the mold support plate143loaded thereon. At this time, a heat treatment for contacting the soft mold134and the mold support plate143is performed at a temperature of 80° C. for 5 minutes.

FIG. 10illustrates a photograph showing PDMS and oligomor which spread to the mold support plate after separating the mold support plate from the soft mold. That is,FIG. 10shows that the soft mold134and the mold support plate143can be adhered to each other without the additional adhesive.

The apparatus and method for fabricating the flat panel display device according to the second embodiment of the present invention can adhere the soft mold134to the mold support plate143by the covalent bonding in the interface between the soft mold134and the mold support plate143. As a result, the fabrication process of the flat panel display device can be simplified and the fabrication cost of the flat panel display device can be reduced.

The apparatus and method for fabricating the flat panel display device according to the present invention can be applied to a process for patterning an electrode layer, an organic material layer and an inorganic material layer included in flat panel display devices such as a field emission display FED, a plasma display panel PDP, and an electroluminescent device EL.

As mentioned above, the apparatus and method for fabricating the flat panel display device according to the present invention has the following advantages.

The method for fabricating the flat panel display device according to the present invention can perform the patterning process without the use of photo process, thereby simplifying the fabrication process of the flat panel display device.

In the apparatus and method for fabricating the flat panel display device according to the present invention, ten or less monomers [SiO(CH3)2] are polymerized to PDMS polymer comprised of the base part and the X-linker part, and the soft mold is formed by using the molding material to which the oligomer having the terminal group of Si—H is inserted. Without the additional adhesive, the soft mold is closely adhered to the mold support plate owing to the covalent bonding in the interface between the soft mold and the mold support plate. As a result, there is no necessary for the process to provide the adhesive and to cure the provided adhesive, thereby simplifying the fabrication process and reducing the fabrication cost.