Method for preventing liquid from permeating

#This invention relates to a method for preventing a liquid from permeating, and more particularly to a method for preventing a liquid from permeating into a cell which facilitates fabrication of a plurality of planels.

#Generally, when a container has to be processed in a liquid without being permeated thereby, a sealing for an outlet of the container is always necessary.

#Please refer to FIGS. 1A˜1B which illustrate a mechanical sealing method in the prior art. In some conditions, two liquid crystal substrates 10 (it only shows one liquid crystal substrate 10 in FIG. 1A) which are adhered to be opposed in parallel to each other to form a container 12 have to be thinned by a chemical etching or a Chemical Machine Polishing (CMP), thus the container 12 including a cell 11 needs to prevent a liquid 13 (especially a hydrofluoric acid, HF used in the chemical etching) from permeating into the cell 11 (between the two liquid crystal substrates 10). That means a layer or more dummy seal 14 must be coated around a periphery 15 of the substrate 10 for preventing the liquid 13 from permeating thereinto. Further, because a gas inside the container 12 must be exhausted through an exhaust 16 formed by the dummy seal 14 when assembling the two substrates 10, the exhaust 16 will be sealed off by a sealing glue 17 after assembling.

#FIG. 1A is a schematic view showing a method for sealing off the exhaust of the liquid crystal substrates in the prior art;

#FIG. 1B is a schematic view showing the substrate immersed in HF according to the prior art;

#FIG. 1C is schematic view showing a narrow channel inside the exhaust of the substrate according to the prior art;

#Please refer to FIGS. 2A˜2E which illustrate a method for preventing liquid from permeating into a cell for facilitating fabrication of a plurality of planels in the first preferred embodiment according to the present invention. This method includes steps of (a) providing a first substrate 22 having a first exhaust area 28 and first portions 23 of a plurality of planels 21; (b) providing a second substrate 24 having a second exhaust area 29 and second portions 25 of the plurality of planels 21; (c) printing a plurality of orienting films 26, 27 respectively on the first and the second portions 23, 25 of the plurality of planels 21 (as shown in FIG. 2B); (d) printing thickening films 281, 291 respectively on the first and the second exhaust areas 28, 29 (as shown in FIG. 2B) for narrowing an intermediate distance of the exhaust areas to prevent the cell 20 from being permeated by the liquid 13 therethrough; (e) coating a dummy seal 241 (as shown in FIG. 2C) around a periphery of the second substrate 24 for preventing the liquid 13 permeating into the cell 20; and (f) assembling the first and the second substrates 22, 24 for forming the cell 20, wherein the plurality of planels 21 are filled therebetween with liquid crystals, the liquid crystals are arranged in response to thickening films 281, 291 between the plurality of planels 21, and the plurality of orienting films 26, 27 and the thickening films 281, 291 are made of a polyimide (PI) and are all printed on the first and the second substrates 22, 24 by a printer (not shown). Moreover, the method further includes a step (e′) of coating a frame seal 242 around the periphery of the second portions 25 of the plurality of planels 21 for filling the liquid crystal between the plurality of planels 21. Furthermore, each of thickening films 281, 291 has a slant end 221, 243 on an inner side thereof with respect to the cell 20 (as shown in FIG. 2E) for gradually increasing the intermediate distance D between the first and the second exhaust areas 28, 29.

#Of course, the first and the second substrates 22, 24 can be LCD (Liquid Crystal Display) substrates, and the liquid 13 can be a HF (hydrofluoric acid) for proceeding a chemical etching process to reduce a weight of the glass substrate of LCD. The first substrate 22 is a TFT (Thin Film Transistor) substrate, and the second substrate 24 is a CF (Color Filter) substrate. And, each of the plurality of planels 21 comprises the first and the second portions 23, 25 and the frame seal 242.

#Please refer to FIGS. 3A˜3E. FIGS. 3A˜3E illustrate the second preferred embodiment according to the present invention which are the method for preventing a liquid from permeating into a cell for facilitating fabrication of a plurality of planels. In this preferred embodiment, the manufacturing process includes steps of (a) providing a first substrate 32 having a first encircling exhaust area 38 and first portions 33 of a plurality of planels 31; (b) providing a second substrate 34 having a second encircling exhaust area 39 and second portions 35 of the plurality of planels 31; (c) printing a plurality of orienting films 36, 37 respectively on the first and the second portions 33, 35 of the plurality of planels 31 (as shown in FIG. 3B); (d) printing encircling thickening films 381, 391 respectively on the first and the encircling exhaust areas 38, 39 for narrowing an intermediate distance thereof to prevent the cell 30 from being permeated by the liquid 13 therethrough; and (e) assembling the first and the second substrates 32, 34 for forming the cell 30, wherein the plurality of planels 31 are filled therebetween with liquid crystals, the liquid crystals are arranged in response to the encircling thickening films 381, 391 between the plurality of planels 31, and the plurality of orienting films 36, 37 and the encircling thickening films 381, 391 are made of a polyimide (PI) and are all printed on the first and the second substrates 32, 34 by a printer (not shown). In addition, each encircling thickening films 381, 391 is a rectangular circle disposed at the encircling exhaust areas 38, 39 around the periphery of the first and the second substrates 32, 34. Moreover, the method further includes a step (d′) of coating a frame seal 341 around the periphery of the second portions 35 of the plurality of planels 31 for filling the liquid crystal between the plurality of planels 31. Furthermore, each of the encircling thickening films 381, 391 has an inner slant circle thereof with respect to the cell for gradually increasing the intermediate distance DC between the first and the second exhaust areas 38, 39. Consequently, as described above, the dummy seal 241 in FIGS. 2C and 2D are replaced by the encircling thickening films 381, 391 in FIGS. 3B˜3D for simplifying the whole manufacturing process.