| Method for fabricating liquid crystal displays with plastic film substrate -> Monitor Keywords |
|
|
  Method for fabricating liquid crystal displays with plastic film substrateUSPTO Application #: 20060084193Title: Method for fabricating liquid crystal displays with plastic film substrate Abstract: A method for fabricating LCDs based on a plastic film is disclosed. The disclosed method comprise the steps of: attaching a double-sided adhesive tape to a supporting plate using one side thereof; fixing a plastic film substrate onto the supporting plate using an unused side of the double-sided adhesive tape after putting the plastic film substrate and the supporting plate with the double-sided adhesive tape attached thereto through a predetermined thermal treatment to thereby form a lower substrate including the supporting plate, plastic film substrate and the double-sided adhesive tape therebetween; preparing an upper substrate using the steps described above; conducting a substrate forming process on each of the lower and the upper substrates; depositing an orientation film on both the lower substrate and the upper substrate, and rubbing the orientation film; detaching the plastic film substrate from the supporting plate of the lower and the upper substrates to form a plastic front substrate and a plastic rear substrate; spraying spacer particles on one of the plastic front substrate and the plastic rear substrate, and dispensing a sealant on the other substrate; and joining the plastic front substrate and the plastic rear substrate at a distance, injecting a liquid crystal material through an injection opening, and closing the injection opening to thereby form a plastic film liquid crystal display. (end of abstract)
Agent: Greenblum & Bernstein, P.L.C - Reston, VA, US Inventors: Won mi Hwang, Jong han Jeong USPTO Applicaton #: 20060084193 - Class: 438030000 (USPTO) Related Patent Categories: Semiconductor Device Manufacturing: Process, Making Device Or Circuit Emissive Of Nonelectrical Signal, Including Integrally Formed Optical Element (e.g., Reflective Layer, Luminescent Material, Contoured Surface, Etc.), Liquid Crystal Component The Patent Description & Claims data below is from USPTO Patent Application 20060084193. Brief Patent Description - Full Patent Description - Patent Application Claims
BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present disclosure relates to a method for fabricating liquid crystal displays; and, more particularly, to a method for fabricating an active matrix liquid crystal display (hereinafter referred to as "AM LCD") and a passive matrix liquid crystal display (hereinafter referred to as "PM LCD") based on a plastic film substrate. [0003] 2. Background of the Related Art [0004] Liquid crystal displays (hereinafter referred to as "LCDs") based on glass substrates were first introduced in the early sixties, and have been widely adopted as information displays in everyday electronics, for example, calculators, watches, cellular phones, PDAs, audio and video equipments, computers, car dashboards, and the like. These LCDs based on glass substrates, despite their widespread uses, are not without problems, the problems being all related to the inherent properties of the glass substrates. For example, these LCDs are not resistant to shock, relatively heavy, are not bendable, and the thickness thereof is limited by the thickness of the glass substrate used. One obvious solution to such problems is to replace the glass substrates with appropriate plastic film substrates. [0005] FIGS. 1a through 1c are cross-sectional views illustrating a prior art method for manufacturing a liquid crystal display using a plastic film substrate as disclosed in Pub. No. US [0006] Referring to FIG. 1a and FIG. 1b, a plastic film substrate 20 is arranged and fixed onto a subsidiary substrate 60 made of a glass through a heat resistant fixing tape 70 placed between the plastic film substrate 20 and the subsidiary substrate 60 along the circumferences thereof. The subsidiary substrate 60 is further fixed onto a processing table 10 by vacuum pressure. An alignment layer 40 for controlling the initial alignment of liquid crystals is then formed on top of the plastic film substrate 20 by first coating an alignment material using an off-set printing method, and rubbing the alignment material with a rubbing rag 50 as shown in FIG. 1b, resulting in a lower plastic substrate 100 as shown in FIG. 1c. A corresponding upper plastic substrate 200 is formed using the processes described above. [0007] A liquid crystal cell is formed between the lower and upper plastic substrates 100 and 200 by facing the lower and upper substrates 100 and 200 at a distance, i.e., cell gap, and partially joining them together with a sealant 30. Subsequently, the fixing tapes 70 on the lower and upper plastic substrates 100 and 200 are removed therefrom and then divided to form liquid crystal cells. These cells are filled up with appropriate liquid crystals to form liquid crystal displays. [0008] In the above-mentioned prior art method for fabricating a LCD with a plastic film substrate, there exist a number of shortcomings. For example, since only circumference of plastic film substrate is glued onto the subsidiary substrate using the heat resistant fixing tape, the plastic film substrate may become unintentionally detached during the manufacturing process and may get damaged by the fixing tape during the detaching process. Further, as shown in FIG. 1c, in order for the processes described above to work, steps must be created on the plastic film substrate along the edge thereof, and this, considering the thickness of the plastic substrate, is extremely difficult and hence costly. In addition, air bubbles may form between the plastic film substrate and the subsidiary substrate, detrimentally affecting the yield and the cost. Finally, the divided subsidiary substrates are not allowed to be reused, increasing the overall manufacturing cost. SUMMARY OF THE INVENTION [0009] It is, therefore, a primary object of the present invention to provide a method for fabricating a LCD based on a plastic film substrate capable of preventing the plastic film substrate from being unintentionally detached, being damaged during the manufacturing thereof, and lowering the manufacturing cost thereof. [0010] In accordance with one aspect of the present invention, there is provided a method for fabricating a plastic film LCD, the method comprising the steps of: attaching a double-sided adhesive tape to a supporting plate using one side thereof; fixing a plastic film substrate onto the supporting plate using an unused side of the double-sided adhesive tape after putting the plastic film substrate and the supporting plate with the double-sided adhesive tape attached thereto through a predetermined thermal treatment to thereby form a lower substrate including the supporting plate, plastic film substrate and the double-sided adhesive tape therebetween; preparing an upper substrate using the steps described above; conducting a substrate forming process on each of the lower and the upper substrates; depositing an orientation film on both the lower substrate and the upper substrate, and rubbing the orientation film; detaching the plastic film substrate from the supporting plate of the lower and the upper substrates to form a plastic front substrate and a plastic rear substrate; spraying spacer particles on one of the plastic front substrate and the plastic rear substrate, and dispensing a sealant on the other substrate; and joining the plastic front substrate and the plastic rear substrate at a distance, injecting a liquid crystal material through an injection opening, and closing the injection opening to thereby form a plastic film liquid crystal display. [0011] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS [0012] The above and other objects and features of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the companying drawings, in which: [0013] FIGS. 1a through 1c are cross-sectional views illustrating a prior art method for manufacturing a liquid crystal display device using a plastic film substrate; [0014] FIGS. 2a through 2g depict cross-sectional views illustrating processes for fabricating LCDs with a plastic film substrate in accordance with a preferred embodiment; [0015] FIG. 2h illustrates a cross-sectional view of an AM LCD constructed pursuant to the processes illustrated in FIGS. 2a through 2g. [0016] FIG. 2i represents a cross-sectional view of a PM LCD constructed pursuant to the processes illustrated in FIGS. 2a through 2g. [0017] FIG. 3 shows, in a flowchart, the method for fabricating LCDs with a plastic film substrate of the present invention according to another preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0018] Herein, a preferred embodiment of the present invention will be described in detail with reference to accompanying drawings. [0019] Referring to FIG. 2a, a double-sided adhesive tape 202 for attaching a plastic film substrate 205 to a supporting plate 201 is first attached to the supporting plate 201 using two rotating press rollers 200 (S301). The plastic film substrate 205 used herein comprises a polymer material selected from the group including, for example, polyestersulfone, polyethylene, polycarbonate, polystyrene, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, polypropylene, aramid, polyamideimide, polyimide, aromatic polyimide, polyetherimide, acrylonitrile butadiene styrene, and polyvinyl chlorides. The Tg (glass transition temperature) of the plastic film substrate 205 determines the maximum processing temperature allowed in the manufacturing of the plastic film LCDs. The plastic film substrate 205, as shown in FIG. 2d, has a thickness ranging between 50 .mu.m and 500 .mu.m, and an ITO (indium-tin oxide layer) on one of its surfaces. Here, the supporting plate 201 may comprise a rigid material selected from the group including acrylics, metals, and glasses. If the supporting plate 201 is made of a glass, apparatuses for manufacturing AM and PM LCDs based on glass panels may be used to manufacture plastic film AM and plastic film PM LCDs. The supporting plate 201 has a thickness ranging between 0.4 mm and 1.1 mm. The double-sided adhesive tape 202 includes a backing 202a and two different adhesive compositions 202b and 202c as shown in FIG. 2b. The backing 202a is made of a heat-resisting film such as polyimide (hereinafter referred to as "PI") or polyethylene (hereinafter referred to as "PET"). The adhesive compositions 202b and 202c, coated on the either-side of the backing 202a respectively, have different adhesive strength. In addition, the double-sided adhesive tape 202 has a dimension equal to or larger than that of the plastic film substrate 205. The adhesive composition 202c coming in contact with the supporting plate 201 has a larger adhesive strength (i.e., ranging between 300 gf/in and 400 gf/in) than that coming in contact with the plastic film substrate 205, allowing the double-sided adhesive tape 202 to be firmly attached to the supporting plate 201. In contrast, the adhesive composition 202b coming in contact with the plastic film substrate (not shown) has a relatively weak adhesive strength (i.e., ranging between 5 gf/in and 100 gf/in), just enough to hold the plastic film substrate in its place, which, in turn, will prevent the plastic film substrate from being damaged by allowing the plastic film substrate to be easily detached from the supporting plate 201 during a detaching process to be performed later. [0020] Referring to FIG. 2c, the supporting plate 201 with the double-sided adhesive tape 202 is placed on a hot plate 204 or a hot oven (not shown) and is kept at a predetermined temperature and for a predetermined time, the temperature ranging between 50.degree. C. and 150.degree. C., and the time ranging between 3 minutes and 20 minutes (S302). Continue reading... Full patent description for Method for fabricating liquid crystal displays with plastic film substrate Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Method for fabricating liquid crystal displays with plastic film substrate patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Method for fabricating liquid crystal displays with plastic film substrate or other areas of interest. ### Previous Patent Application: Process for forming sharp silicon structures Next Patent Application: Methods for fabricating solid state image sensor devices having non-planar transistors Industry Class: Semiconductor device manufacturing: process ### FreshPatents.com Support Thank you for viewing the Method for fabricating liquid crystal displays with plastic film substrate patent info. IP-related news and info Results in 1.80912 seconds Other interesting Feshpatents.com categories: Qualcomm , Schering-Plough , Schlumberger , Seagate , Siemens , Texas Instruments , |
||
