JP6413496B2 - Manufacturing method of liquid crystal display panel - Google Patents

Description

  The present invention relates to a method for manufacturing a liquid crystal display panel.

  In manufacturing a liquid crystal display (LCD) panel, it is necessary to cut a brittle substrate such as a glass substrate. First, a scribe line is formed on the substrate, and then the substrate is divided along the scribe line. The scribe line can be formed by mechanically processing the substrate using the cutting edge. When the cutter is displaced on the substrate, a trench due to plastic deformation is formed on the substrate, and at the same time, a vertical crack is formed immediately below the trench. Thereafter, stress is applied, which is called a break process. The substrate is divided by causing the crack to advance completely in the thickness direction by the break process.

  Patent Document 1 exemplifies a method for manufacturing a panel product. According to this example, first, a glass substrate having a structure in which a first substrate and a second substrate are bonded together is prepared. A scribe line is formed on each of the front and back surfaces of the glass substrate. When the break roller is pressed against each of the front and back surfaces of the glass substrate, the glass substrate is divided.

JP 2011-161694 A

  According to the technique described in the above publication, the break roller must be pressed against each of one surface and the other surface of the glass substrate (cell substrate). For this reason, after processing for one surface, it was necessary to invert the cell substrate in order to perform processing for the other surface.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method of manufacturing a liquid crystal display panel that can perform a break process without inverting the cell substrate.

  The manufacturing method of the liquid crystal display panel of the present invention includes the following steps.

  A first brittle substrate having a first main surface and a second main surface opposite to the first main surface and having a thickness direction perpendicular to the first main surface is prepared. A second brittle substrate having a third main surface and a fourth main surface opposite to the third main surface is prepared.

  The cutting edge is pressed against the first main surface of the first brittle substrate. By causing the pressed blade edge to slide on the first main surface of the first brittle substrate, plastic deformation is generated on the first main surface of the first brittle substrate, so that the first having a groove shape is formed. Trench lines are formed. The first trench line is formed so as to obtain a crackless state in which the first brittle substrate is continuously connected in a direction intersecting the first trench line immediately below the first trench line. The

  After the first trench line is formed, the first brittle substrate and the second brittleness so that the first main surface of the first brittle substrate and the third main surface of the second brittle substrate face each other. The substrates are bonded together. The first brittle substrate and the second brittle substrate are bonded together such that the first trench line formed in the first brittle substrate is at least partially covered by the second brittle substrate.

  After the first brittle substrate and the second brittle substrate are bonded to each other, the first crack line is formed by extending the crack of the first brittle substrate in the thickness direction along the first trench line. Is done. The first brittle substrate is disconnected from the first crack line immediately below the first trench line in the direction intersecting the first trench line.

  A second crack line is formed on the fourth main surface of the second brittle substrate.

  Each of the first crack line and the second crack line is obtained by warping the first brittle substrate and the second brittle substrate by locally applying a load on the second main surface of the first brittle substrate. A 1st brittle board | substrate and a 2nd brittle board | substrate are parted along this.

  According to the present invention, the break process of the first brittle substrate and the second brittle substrate is performed by applying a load on the second main surface of the first brittle substrate. Thereby, it is not necessary to invert the cell substrate having the first brittle substrate and the second brittle substrate in the break process. Therefore, the break process can be performed more easily.

1A is a perspective view schematically showing a configuration of a liquid crystal display panel in Embodiment 1 of the present invention, and FIG. 1B is a schematic sectional view taken along line IB-IB in FIG. It is a flowchart which shows schematically the manufacturing method of the liquid crystal display panel of FIG. End view (A) along line IIIA-IIIA (FIG. 4) schematically showing the first step of the substrate scribing method in the method of manufacturing a liquid crystal display panel in Embodiment 1 of the present invention, the second step schematically , End view (B) along line IIIB-IIIB (FIG. 5), end view (C) along line IIIC-IIIC (FIG. 6) schematically showing the third step, and fourth step schematically. FIG. 8D is an end view (D) taken along line IIID-IIID (FIG. 7). It is a top view which shows roughly the 1st process of the substrate scribing method in the manufacturing method of the liquid crystal display panel in Embodiment 1 of this invention. It is a top view which shows roughly the 2nd process of the substrate scribing method in the manufacturing method of the liquid crystal display panel in Embodiment 1 of this invention. It is a top view which shows roughly the 3rd process of the substrate scribing method in the manufacturing method of the liquid crystal display panel in Embodiment 1 of this invention. It is a top view which shows roughly the 4th process of the substrate scribing method in the manufacturing method of the liquid crystal display panel in Embodiment 1 of this invention. The end view (A) which shows schematically the structure of the trench line formed in the board | substrate scribe method in the manufacturing method of the liquid crystal display panel in Embodiment 1 of this invention, and the end view which shows the structure of a crack line schematically ( B). FIG. 12 is an end view (A) schematically showing a first step of a substrate break method in the method of manufacturing a liquid crystal display panel in Embodiment 1 of the present invention, and a line IXB-IXB (FIG. 12) schematically showing a second step. FIG. It is the front view (A) which shows a mode when the load application in FIG. 9 (A) is performed by a break bar, and the schematic sectional drawing (B) along line XB-XB of FIG. 10 (A). It is the front view (A) which shows a mode when the load application in FIG. 9 (A) is performed with a break roller, and the schematic sectional drawing (B) which follows the line XIB-XIB of FIG. 11 (A). FIG. 10 is a schematic plan view corresponding to FIG. It is an end elevation (A) and (B) which shows each of the 1st and 2nd process in the 1st comparative example. It is an end view (A)-(C) which shows each of the 1st-3rd process in the 2nd comparative example. End view (A) along line XVA-XVA (FIG. 16) schematically showing the first step of the manufacturing method of the liquid crystal display panel in Embodiment 2 of the present invention, line schematically showing the second step End view (B) along XVB-XVB (FIG. 17), schematically showing the third step, end view (C) along line XVC-XVC (FIG. 18), schematically showing the fourth step, FIG. 20 is an end view (D) along XVD-XVD (FIG. 19) and an end view (E) along line XVE-XVE (FIG. 20) schematically showing the fifth step. It is a top view which shows roughly the 1st process of the manufacturing method of the liquid crystal display panel in Embodiment 2 of this invention. It is a top view which shows roughly the 2nd process of the manufacturing method of the liquid crystal display panel in Embodiment 2 of this invention. It is a top view which shows roughly the 3rd process of the manufacturing method of the liquid crystal display panel in Embodiment 2 of this invention. It is a top view which shows roughly the 4th process of the manufacturing method of the liquid crystal display panel in Embodiment 2 of this invention. It is a top view which shows roughly the 5th process of the manufacturing method of the liquid crystal display panel in Embodiment 2 of this invention. It is a flowchart which shows schematically the manufacturing method of the liquid crystal display panel in Embodiment 3 of this invention. End view (A) along line XXIIA-XXIIA (FIG. 23) schematically showing the first step of the liquid crystal display panel manufacturing method in Embodiment 3 of the present invention, line schematically showing the second step, End view (B) along XXIB-XXIIB (FIG. 24), schematically showing the third step, end view (C) along line XXIIC-XXIIC (FIG. 25), schematically showing the fourth step, FIG. 26 is an end view (D) along XXIID-XXIID (FIG. 26) and an end view (E) along line XXIIE-XXIIE (FIG. 27) schematically showing the fifth step. It is a top view which shows roughly the 1st process of the manufacturing method of the liquid crystal display panel in Embodiment 3 of this invention. It is a top view which shows roughly the 2nd process of the manufacturing method of the liquid crystal display panel in Embodiment 3 of this invention. It is a top view which shows roughly the 3rd process of the manufacturing method of the liquid crystal display panel in Embodiment 3 of this invention. It is a top view which shows roughly the 4th process of the manufacturing method of the liquid crystal display panel in Embodiment 3 of this invention. It is a top view which shows roughly the 5th process of the manufacturing method of the liquid crystal display panel in Embodiment 3 of this invention. It is a flowchart which shows schematically the manufacturing method of the liquid crystal display panel in the modification of Embodiment 3 of this invention. FIG. 32 is an end view along line XXIX-XXIX (FIG. 30) schematically showing one step of a method of manufacturing a liquid crystal display panel in a modification of Embodiment 3 of the present invention. It is a top view which shows roughly 1 process of the manufacturing method of the liquid crystal display panel in the modification of Embodiment 3 of this invention. It is a flowchart which shows schematically the manufacturing method of the liquid crystal display panel in Embodiment 4 of this invention. End view (A) along line XXXIIA-XXXIIA (FIG. 33), schematically showing the second step, schematically showing the first step of the liquid crystal display panel manufacturing method in Embodiment 4 of the present invention, XXXIIB-XXXIIB (FIG. 34) end view (B), schematically showing the third step, line XXXIIC-XXXIIC (FIG. 35) end view (C), schematically showing the fourth step, line FIG. 37 is an end view (D) along XXXIID-XXXIID (FIG. 36), and an end view (E) along line XXXIIE-XXXIIE (FIG. 37) schematically showing the fifth step. It is a top view which shows roughly the 1st process of the manufacturing method of the liquid crystal display panel in Embodiment 4 of this invention. It is a top view which shows roughly the 2nd process of the manufacturing method of the liquid crystal display panel in Embodiment 4 of this invention. It is a top view which shows roughly the 3rd process of the manufacturing method of the liquid crystal display panel in Embodiment 4 of this invention. It is a top view which shows roughly the 4th process of the manufacturing method of the liquid crystal display panel in Embodiment 4 of this invention. It is a top view which shows roughly the 5th process of the manufacturing method of the liquid crystal display panel in Embodiment 4 of this invention. It is a flowchart which shows schematically the manufacturing method of the liquid crystal display panel in the modification of Embodiment 4 of this invention. FIG. 49 is an end view along line XXXIX-XXXIX (FIG. 40) schematically showing one step of a method for manufacturing a liquid crystal display panel in a modification of Embodiment 4 of the present invention. It is a top view which shows roughly 1 process of the manufacturing method of the liquid crystal display panel in the modification of Embodiment 4 of this invention. It is a flowchart which shows schematically the manufacturing method of the liquid crystal display panel in Embodiment 5 of this invention. FIG. 42A is a side view schematically showing the configuration of the instrument used in the method for manufacturing a liquid crystal display panel according to Embodiment 6 of the present invention, and the configuration of the cutting edge of the instrument is indicated by the arrow XLIIB in FIG. It is a top view (B) shown roughly from a viewpoint. It is a top view (A) and (B) which shows each roughly the 1st and 2nd process of the manufacturing method of the liquid crystal display panel in Embodiment 6 of this invention. It is a top view (A) and (B) which shows each roughly the 1st and 2nd process of the manufacturing method of the liquid crystal display panel of the 1st modification of Embodiment 6 of this invention. It is a top view which shows roughly the manufacturing method of the liquid crystal display panel of the 2nd modification of Embodiment 6 of this invention. It is a top view which shows roughly the manufacturing method of the liquid crystal display panel of the 3rd modification of Embodiment 6 of this invention. It is a top view which shows roughly the 1st process of the manufacturing method of the liquid crystal display panel in Embodiment 7 of this invention. It is a top view which shows roughly the 2nd process of the manufacturing method of the liquid crystal display panel in Embodiment 7 of this invention. It is a top view which shows roughly the 3rd process of the manufacturing method of the liquid crystal display panel in Embodiment 7 of this invention. It is a top view which shows roughly the manufacturing method of the liquid crystal display panel of the 2nd modification of Embodiment 7 of this invention. It is a top view (A) and (B) which shows each roughly the 1st and 2nd process of the manufacturing method of the liquid crystal display panel in Embodiment 8 of this invention. It is a top view (A) and (B) which shows each roughly the 1st and 2nd process of the manufacturing method of the liquid crystal display panel in Embodiment 9 of this invention. It is a top view which shows roughly the manufacturing method of the liquid crystal display panel of the modification of Embodiment 9 of this invention. A side view (A) schematically showing the configuration of the instrument used in the method for manufacturing a liquid crystal display panel according to Embodiment 10 of the present invention, and the configuration of the cutting edge of the instrument shown by the arrow LIVB in FIG. 54 (A) It is a top view (B) shown roughly from a viewpoint.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
Referring to FIGS. 1A and 1B, LCD panel 101 of the present embodiment includes a CF (color filter) substrate 11 (first brittle substrate in the present embodiment) and a TFT (thin film transistor) substrate. 12 (second brittle substrate in the present embodiment), a seal portion 21, and a liquid crystal layer 20.

  The CF substrate 11 has an inner surface SF1 (first main surface in the present embodiment) and an opposite outer surface SF2 (second main surface in the present embodiment) as main surfaces. The CF substrate 11 has a thickness direction DT perpendicular to the inner surface SF1. The CF substrate 11 is specifically a glass substrate, and has a color filter, a black matrix, and an alignment film (not shown). The TFT substrate 12 has, as main surfaces, an inner surface SF3 (third main surface in the present embodiment) and an opposite outer surface SF4 (fourth main surface in the present embodiment). The TFT substrate 12 has a thickness direction DT perpendicular to the inner surface SF3. The TFT substrate 12 is specifically a glass substrate, and includes wiring, active elements, electrodes, and an alignment film (not shown).

  The CF substrate 11 and the TFT substrate 12 are bonded to each other through the seal portion 21 so that the inner surfaces SF1 and SF3 face each other. The liquid crystal layer 20 is disposed in the gap between the inner surfaces SF1 and SF3 and is sealed by the seal portion 21. The inner surface SF3 of the TFT substrate 12 has a portion covered with the liquid crystal layer 20 or the seal portion 21. The inner surface SF3 may have an exposed terminal region SF3e. The terminal region SF3e can be used for connecting the TFT substrate 12 to external wiring.

  Next, a substrate scribing method in the manufacturing method of the LCD panel 101 will be described below.

  Referring to FIGS. 3A and 4, a CF substrate 11 is prepared (FIG. 2: step S11). At this time, the CF substrate 11 is a substrate (mother substrate) including a plurality of regions cut out to obtain a plurality of final products. Next, the blade edge is pressed against the inner surface SF1 of the CF substrate 11 (FIG. 2: step S12). The pressed blade edge is slid on the inner surface SF1 of the CF substrate 11 to cause plastic deformation on the inner surface SF1 of the CF substrate 11, thereby forming a trench line TL having a groove shape (FIG. 2: Step S13).

  Referring to FIG. 8A, trench line TL of CF substrate 11 is formed so as to obtain a crackless state. The crackless state means that the substrate (CF substrate 11 in the figure) is in a direction DC that is directly below the trench line TL and intersects the extending direction of the trench line TL (the direction perpendicular to the cross section shown in FIG. 8A). It is a state of continuous connection. In the crackless state, the trench line TL is formed by plastic deformation, but no crack is formed along the trench line TL. Therefore, even if an external force that simply generates a bending moment is applied to the substrate as in the conventional break process, the division along the trench line TL does not easily occur. Therefore, the break process along the trench line TL is not performed in the crackless state.

  Referring to FIGS. 3B and 5, the TFT substrate 12 is prepared (FIG. 2: step S21). At this time, the TFT substrate 12 is a substrate (mother substrate) including a plurality of regions cut out to obtain a plurality of final products. Next, the blade edge is pressed against the outer surface SF4 of the TFT substrate 12 (FIG. 2: Step S22). The pressed blade edge is slid on the outer surface SF4 of the TFT substrate 12 to cause plastic deformation on the outer surface SF4 of the TFT substrate 12, thereby forming a trench line TL having a groove shape (FIG. 2: Step S23).

  3C and 6, next, the CF substrate 11 and the TFT substrate 12 are bonded to each other so that the inner surface SF1 of the CF substrate 11 and the inner surface SF3 of the TFT substrate 12 face each other (FIG. 2). : Step S40). Thereby, the cell substrate 10 which is a laminate of the CF substrate 11 and the TFT substrate 12 is obtained. The trench line TL formed in the CF substrate 11 is covered with the TFT substrate 12. In the present embodiment, the trench line TL formed in the CF substrate 11 is partially covered by the TFT substrate 12. In other words, the trench line TL formed on the inner surface SF1 of the CF substrate 11 is partially exposed.

  Next, referring to FIG. 3D and FIG. 7, along the trench line TL of the CF substrate 11 and the TFT substrate 12, a crack line CL, which is a line in which a crack extends on the substrate, is formed. (FIG. 2: Step S60). Formation of the crack line CL is performed by extending a crack in the substrate in the thickness direction along the trench line TL.

  Referring to FIG. 8B, the direction DC where the CF substrate 11 intersects the extending direction of the trench line TL (the direction perpendicular to the cross section shown in FIG. 8B) immediately below the trench line TL by the crack line CL. The continuous connection is broken. Here, “continuous connection” means a connection that is not interrupted by a crack. In addition, in the state where the continuous connection is cut as described above, the portions of the substrate may be in contact with each other through the cracks of the crack line CL. The same applies to the TFT substrate 12.

  Formation of the crack line CL of the CF substrate 11 is started by applying a stress that releases the distortion of the internal stress in the vicinity of the trench line TL to the CF substrate 11 at the exposed end of the trench line TL. The application of stress can be performed, for example, by applying external stress by pressing the blade edge again on the formed trench line TL, or by heating by laser light irradiation. As a result, a crack extends along the trench line TL from the exposed portion of the trench line TL of the CF substrate 11 to the portion covered with the TFT substrate 12. The same applies to the TFT substrate 12.

  Next, the break process with respect to the cell substrate 10 (FIG. 3D) subjected to the scribe process will be described below.

  With reference to FIG. 9A, the cell substrate 10 is arranged on the break rug 61 affixed to the table 60 so that the outer surface SF2 of the CF substrate 11 which is a surface where the crack line CL is not formed is exposed. Is done.

  Next, the CF substrate 11 and the TFT substrate 12 are warped by applying a load locally on the outer surface SF2. Specifically, loads are sequentially applied at break points B0 to B2 on the outer surface SF2. The break point B0 overlaps with the crack lines CL of the CF substrate 11 and the TFT substrate 12 in a plan view, so that the CF substrate 11 and the TFT substrate 12 move along the crack lines CL of the CF substrate 11 and the TFT substrate 12, respectively. Divided. The break point B1 overlaps only with the crack line CL of the CF substrate 11 in plan view, and thus the CF substrate 11 is divided along the crack line CL of the CF substrate 11. The break portion B2 overlaps only with the crack line CL of the TFT substrate 12 in plan view, and thus the TFT substrate 12 is divided along the crack line CL of the TFT substrate 12.

  Referring to FIGS. 10A and 10B, load LD can be applied to the entire crack line CL by using break bar 71. In this case, the division along the entire crack line CL is performed almost simultaneously. Referring to FIGS. 11A and 11B, or the load LD can be applied by using a break roller 72. In this case, the division along the crack line CL gradually proceeds with the progress PR of the break roller 72 by the rotation RT on the outer surface SF2.

  9B and 12, as described above, as step S90 (FIG. 2), the CF substrate 11 is divided along the crack line CL of the CF substrate 11, and the crack line of the TFT substrate 12 is also divided. The TFT substrate 12 is divided along CL. That is, a break process for the cell substrate 10 is performed.

  Referring to FIG. 1B again, the liquid crystal layer 20 is formed by injecting liquid crystal into the gap between the CF substrate 11 and the TFT substrate 12. Thus, a plurality of LCD panels 101 can be obtained from one cell substrate 10 (FIG. 9A).

  Next, a first comparative example will be described. Referring to FIGS. 13A and 13B, CF substrate 11 and TFT substrate 12 are bonded to each other. Next, scribe lines SL are formed on the outer surfaces SF2 and SF4 of the CF substrate 11 and the TFT substrate 12, respectively. The scribe line SL can be formed by a known typical scribe technique, and has a line of a vertical crack formed at the time of scribing. That is, the scribe line SL includes a crack line. Next, the CF substrate 11 and the TFT substrate 12 are divided along the scribe line SL. At this time, the load application L1 on the outer surface SF4 of the TFT substrate 12 is necessary for the division along the scribe line SL of the CF substrate 11, and the division of the CF substrate 11 along the scribe line SL of the TFT substrate 12 is necessary. The load application L2 on the outer surface SF2 is necessary. For this reason, it is necessary to invert the cell substrate 10 in the break process.

  On the other hand, according to the present embodiment, as described with reference to FIG. 9A, the load is applied only on the outer surface SF2 of the CF substrate 11. Therefore, it is not necessary to invert the cell substrate 10. Thereby, a break process can be performed more easily. For example, the apparatus for a break process can be simplified. In addition, the time required for the break process can be shortened.

  Next, a second comparative example will be described. 14A and 14B, the CF substrate 11 on which the scribe line SL is formed and the TFT substrate 12 on which the scribe line SL is formed are separately prepared. Referring to FIG. 14C, the CF substrate 11 and the TFT substrate 12 are bonded to each other. Thereafter, the CF substrate 11 and the TFT substrate 12 are divided along the scribe line SL by the same method as in FIG. In this comparative example, since the CF substrate 11 and the TFT substrate 12 are bonded together after the scribe line SL accompanied by the vertical crack is formed, the crack of the scribe line SL extends unintentionally in the thickness direction, At least one of the CF substrate 11 and the TFT substrate 12 tends to be divided before the intended time point. As a result, it may be difficult to continue the manufacturing process of the LCD panel 101 (FIG. 1B).

  On the other hand, according to the present embodiment, a trench line TL (FIG. 8A) that does not have a crack is formed immediately below the line that defines the position where the CF substrate 11 is divided. The crack line CL (FIG. 8B) to be used as a direct trigger for the division is formed after the formation of the trench line TL. Thereby, the CF substrate 11 after the formation of the trench line TL and before the formation of the crack line CL is easily divided because the position to be divided is defined by the trench line TL but the crack line CL is not yet formed. It is in a stable state (crackless state) that does not occur. In this stable state, the TFT substrate 12 is disposed on the trench line TL of the CF substrate 11, that is, on a line that defines a position where the CF substrate 11 is divided. Thereafter, the crack line CL to be used as a direct trigger for the division is formed by extending the crack along the trench line TL. Thereby, the crack line CL can be formed at a position covered with the TFT substrate 12. As described above, the portion covered with the TFT substrate 12 on the CF substrate 11 while avoiding the CF substrate 11 being unintentionally divided during the work related to the bonding of the CF substrate 11 and the TFT substrate 12. In addition, it is possible to provide a line to be divided along the line.

  Similarly, while avoiding unintentional division of the TFT substrate 12 during work related to bonding, the portion covered by the CF substrate 11 on the TFT substrate 12 is also divided along that line. A line can be provided.

  Note that the formation process of the crack line CL in the present embodiment is essentially different from a conventional so-called break process. In the break process, the already formed crack is further extended in the thickness direction. On the other hand, the formation process of the crack line CL in the present embodiment brings about a change from a crackless state obtained by forming the trench line TL to a state having a crack. This change is considered to be caused by the release of internal stress that the crackless state has. The state of the plastic deformation at the time of forming the trench line TL and the magnitude and directionality of the internal stress generated by the formation of the trench line TL are the same as in the case where rolling of the rotary blade is used, as in this embodiment. This is considered to be different from the case where the sliding of the blade edge is used, and when the sliding of the blade edge is used, cracks are likely to occur in a wider scribe condition. Moreover, some kind of trigger is necessary to release the internal stress, and it is considered that the occurrence of cracks on the trench line TL due to the application of external stress as described above acts as such a trigger. Details of a preferable method of forming the trench line TL and the crack line CL will be described later.

(Embodiment 2)
15A to 15E are cross-sectional views schematically showing first to fifth steps of the method of manufacturing liquid crystal display panel 101 (FIGS. 1A and 1B) in the present embodiment. It is. The cross sections of FIGS. 15A to 15E are line XVA-XVA (FIG. 16), line XVB-XVB (FIG. 17), line XVC-XVC (FIG. 18), and line XVD-XVD (FIG. 19). And along the line XVE-XVE (FIG. 20). In the present embodiment, unlike the first embodiment, the TFT substrate 12 corresponds to the first brittle substrate, and the CF substrate 11 corresponds to the second brittle substrate. The inner surface SF3 corresponds to the first main surface, the outer surface SF4 corresponds to the second main surface, the inner surface SF1 corresponds to the third main surface, and the outer surface SF2 corresponds to the fourth main surface.

  In the present embodiment, the trench line TL of the TFT substrate 12 is formed on the inner surface SF3 (FIG. 15A), and the trench line TL of the CF substrate 11 is formed on the outer surface SF2 (FIG. 15B). )). Thereby, the crack line CL of the TFT substrate 12 is formed on the inner surface SF3, and the crack line CL of the CF substrate 11 is formed on the outer surface SF2 (FIG. 15D). The break method itself as step S90 (FIG. 2) is substantially the same as that in FIG. 9A of the first embodiment, but the load is applied not on the outer surface SF2 but on the outer surface SF4.

  Since the configuration other than the above is substantially the same as the configuration of the first embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof is not repeated.

  Also according to the present embodiment, substantially the same effect as in the first embodiment can be obtained. In addition, according to the present embodiment, the trench line TL can be arranged on the outer surface SF2 instead of the inner surface SF1, which often has a complicated configuration by arranging a color filter, a black matrix, and the like. Thereby, the trench line TL of the CF substrate 11 can be stably formed.

(Embodiment 3)
FIG. 21 is a flowchart schematically showing a method for manufacturing LCD panel 101 (FIGS. 1A and 1B) in the present embodiment. Each of the cross sections of FIGS. 22A to 22E is a line XXIIA-XXIIA (FIG. 23), a line XXIIB-XXIIB (FIG. 24), a line XXIIC-XXIIC (FIG. 25), and a line XXIID-XXIID (FIG. 26). And along the line XXIIE-XXIIE (FIG. 27).

  With reference to FIG. 22A and FIG. 23, the CF substrate 11 on which the trench line TL is formed is prepared by steps S11 to S13 (FIG. 21) similar to those of the first embodiment.

  With reference to FIG. 22 (B) and FIG. 24, the TFT substrate 12 is prepared (FIG. 21: step S21). The CF substrate 11 and the TFT substrate 12 are bonded to each other so that the inner surface SF1 of the CF substrate 11 and the inner surface SF3 of the TFT substrate 12 face each other (FIG. 21: Step S40). Thereby, the cell substrate 10 which is a laminate of the CF substrate 11 and the TFT substrate 12 is obtained. The trench line TL formed in the CF substrate 11 is covered with the TFT substrate 12. In the present embodiment, the trench line TL formed in the CF substrate 11 is partially covered by the TFT substrate 12. In other words, the trench line TL formed on the inner surface SF1 of the CF substrate 11 is partially exposed.

  With reference to FIG. 22C and FIG. 25, next, a crack line CL is formed along the trench line TL of the CF substrate 11 (FIG. 21: Step S61).

  With reference to FIG. 22D and FIG. 26, next, scribe line SL is formed on outer surface SF4 of TFT substrate 12 (FIG. 21: step S72). As described above, the scribe line SL includes a vertical crack line (crack line) formed during scribing. The scribe line SL is formed by displacing the blade edge on the outer surface SF4 of the TFT substrate 12 along the line where the scribe line SL is to be formed.

  Further, referring to FIGS. 22E and 27, as step S90 (FIG. 21), the CF substrate 11 is divided along the crack line CL of the CF substrate 11, and along the scribe line SL of the TFT substrate 12. The TFT substrate 12 is divided. Note that the dividing method is almost the same as that in FIG.

  Referring to FIG. 1B again, the liquid crystal layer 20 is formed by injecting liquid crystal into the gap between the CF substrate 11 and the TFT substrate 12. Thus, a plurality of LCD panels 101 can be obtained from one cell substrate 10 (FIG. 22D).

  Since the configuration other than the above is substantially the same as the configuration of the first embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof is not repeated.

  Also according to the present embodiment, substantially the same effect as in the first embodiment can be obtained.

  Further, according to the present embodiment, the CF substrate 11 and the TFT substrate 12 are already bonded to each other when the scribe line SL is formed, and the crack line CL is formed in the CF substrate 11. Therefore, even if the vertical crack of the scribe line SL is extended for some reason and the division along the scribe line SL is unintentionally caused, there is usually no problem.

  In addition, the scribe line SL of the TFT substrate 12 is formed on the outer surface SF4 instead of the inner surface SF3, which often has a complicated configuration due to the arrangement of TFTs and the like. Thereby, the scribe line SL can be stably formed.

  Referring to FIG. 28, in the modification of the present embodiment, the order of steps S61 and S72 (FIG. 21) described above is switched. 29 and 30 schematically show the configuration at the time when the scribe line SL is formed in step S72.

(Embodiment 4)
FIG. 31 is a flowchart schematically showing a method for manufacturing LCD panel 101 (FIGS. 1A and 1B) in the present embodiment. The cross sections of FIGS. 32A to 32E are respectively the line XXXIIA-XXXIIA (FIG. 33), the line XXXIIB-XXXIIB (FIG. 34), the line XXXIIC-XXXIIC (FIG. 35), and the line XXXIID-XXXIIID (FIG. 36). And along the line XXXIIE-XXXIIE (FIG. 37).

  Referring to FIGS. 32A and 33, TFT substrate 12 on which trench line TL is formed is prepared by steps S21 to S23 (FIG. 31) similar to those of the first embodiment.

  Referring to FIGS. 32B and 34, the CF substrate 11 is prepared (FIG. 31: step S11). The CF substrate 11 and the TFT substrate 12 are bonded together so that the inner surface SF1 of the CF substrate 11 and the inner surface SF3 of the TFT substrate 12 face each other (FIG. 31: Step S40). Thereby, the cell substrate 10 which is a laminate of the CF substrate 11 and the TFT substrate 12 is obtained. The trench line TL formed in the TFT substrate 12 is covered with the CF substrate 11. In the present embodiment, the trench line TL formed in the TFT substrate 12 is partially covered with the CF substrate 11. In other words, the trench line TL formed on the inner surface SF3 of the TFT substrate 12 is partially exposed.

  Referring to FIG. 32C and FIG. 35, next, a crack line CL is formed along the trench line TL of the TFT substrate 12 (FIG. 31: step S62).

  Referring to FIGS. 32 (D) and 36, scribe line SL is then formed on outer surface SF2 of CF substrate 11 (FIG. 31: step S71). As described above, the scribe line SL can be formed by a known typical scribe technique, and has a line of a vertical crack formed at the time of scribing.

  32E and 37, as step S90 (FIG. 31), the TFT substrate 12 is divided along the crack line CL of the TFT substrate 12, and along the scribe line SL of the CF substrate 11. The CF substrate 11 is divided.

  Next, liquid crystal is injected into the gap between the CF substrate 11 and the TFT substrate 12 to form the liquid crystal layer 20 (FIG. 1B). Thus, a plurality of LCD panels 101 (FIG. 1B) are obtained from one cell substrate 10 (FIG. 32D).

  Since the configuration other than the above is substantially the same as the configuration of the second embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof will not be repeated.

  Also according to the present embodiment, substantially the same effect as in the first embodiment can be obtained.

  In addition, according to the present embodiment, the CF substrate 11 and the TFT substrate 12 are already bonded to each other when the scribe line SL is formed, and the crack line CL is formed on the TFT substrate 12. Therefore, even if the vertical crack of the scribe line SL is extended for some reason and the division along the scribe line SL is unintentionally caused, there is usually no problem.

  Further, the scribe line SL of the CF substrate 11 is formed on the outer surface SF2 instead of the inner surface SF1, which often has a complicated configuration, by arranging a color filter, a black matrix, and the like. Thereby, the scribe line SL can be stably formed.

  Referring to FIG. 38, in the modification of the present embodiment, the order of steps S62 and S71 (FIG. 31) described above is switched. 39 and 40 schematically show the configuration at the time when the scribe line SL is formed in step S71.

(Embodiment 5)
FIG. 41 is a flowchart schematically showing a method for manufacturing LCD panel 101 (FIGS. 1A and 1B) in the present embodiment. Unlike the second to fourth embodiments, in this embodiment, the definition of the position to be divided for either the CF substrate 11 or the TFT substrate 12 is the formation of the trench line TL (step S13 or S23) and the scribe line. This is performed separately from the formation of SL (step S70). This division method is arbitrary. For example, in the XY orthogonal coordinates of the planar layout, a trench line TL along the X axis and a scribe line SL along the Y axis are formed. Note that the order of steps S60 and S70 may be changed.

  Since the configuration other than the above is substantially the same as the configuration of the above-described second to fourth embodiments, the same or corresponding elements are denoted by the same reference numerals, and description thereof is not repeated.

(Embodiment 6)
A cutting tool having a cutting edge used for forming the trench line TL in each of the above embodiments will be described below.

  42A and 42B show a state in which the blade edge 51 is pressed against the CF substrate 11. The cutting instrument 50 has a cutting edge 51 and a shank 52. The blade edge 51 is provided with a top surface SD1 (first surface) and a plurality of surfaces surrounding the top surface SD1. The plurality of surfaces include a side surface SD2 (second surface) and a side surface SD3 (third surface). The top surface SD1, the side surfaces SD2, and SD3 (first to third surfaces) face different directions and are adjacent to each other. The blade edge 51 has a vertex at which the top surface SD1, the side surfaces SD2 and SD3 merge, and the protrusion PP of the blade edge 51 is configured by this vertex. Further, the side surfaces SD2 and SD3 form ridge lines constituting the side portion PS of the blade edge 51. The side part PS extends linearly from the protrusion part PP. Moreover, since the side part PS is a ridgeline as mentioned above, it has the convex shape extended linearly.

  The cutting edge 51 is preferably a diamond point. That is, the cutting edge 51 is preferably made of diamond from the viewpoint that the hardness and the surface roughness can be reduced. More preferably, the cutting edge 51 is made of single crystal diamond. More preferably, crystallographically, the top surface SD1 is a {001} plane, and each of the side surfaces SD2 and SD3 is a {111} plane. In this case, although the side surfaces SD2 and SD3 have different orientations, they are crystal surfaces that are equivalent to each other in terms of crystallography.

  Diamond that is not a single crystal may be used. For example, polycrystalline diamond synthesized by a CVD (Chemical Vapor Deposition) method may be used. Alternatively, polycrystalline diamond that is sintered from fine graphite or non-graphitic carbon without containing a binder such as an iron group element, or sintered diamond obtained by bonding diamond particles with a binder such as an iron group element May be used.

  The shank 52 extends along the axial direction AX. The blade edge 51 is preferably attached to the shank 52 so that the normal direction of the top surface SD1 is approximately along the axial direction AX.

  In order to form the trench line TL (FIG. 8A) using the cutting tool 50, the protrusion PP and the side PS of the cutting edge 51 on the inner surface SF1 of the CF substrate 11 have the thickness that the CF substrate 11 has. Pressed in the direction DT. Next, the cutting edge 51 is slid on the inner surface SF1 approximately along the direction in which the side portion PS is projected onto the inner surface SF1. Thus, a groove-like trench line TL without a vertical crack is formed on the inner surface SF1. Although the trench line TL is generated by plastic deformation of the CF substrate 11, the CF substrate 11 may be slightly shaved at this time. However, since such scraping can generate fine fragments, it is preferable that the amount is as small as possible.

  There are a case where the trench line TL and the crack line CL are simultaneously formed by sliding the blade edge 51 (FIG. 8B), and a case where only the trench line TL is formed (FIG. 8A). The crack line CL is a crack extending in the thickness direction DT from the recess of the trench line TL, and extends linearly on the inner surface SF1. According to the method described later, after only the trench line TL is formed, the crack line CL can be formed along the trench line TL.

  Next, the method for dividing the CF substrate 11 (first brittle substrate in the present embodiment) will be described below with particular attention paid. For easy understanding of the drawings and the explanation, only the division along one direction (the horizontal direction in each plan view) will be described. However, as described in the first to fifth embodiments, the division may be performed in plural. (For example, the horizontal direction and the vertical direction in each plan view) can be divided. A similar dividing method can be applied to the TFT substrate 12 (second brittle substrate in the present embodiment). The TFT substrate 12 may be a first brittle substrate and the CF substrate 11 may be a second brittle substrate. Further, the attachment between the CF substrate 11 and the TFT substrate 12 is as described in the first to fifth embodiments, and the illustration thereof is omitted.

  Referring to FIG. 43A, the CF substrate 11 has a flat inner surface SF1. The edge surrounding the inner surface SF1 includes a side ED1 (first side) and a side ED2 (second side) that face each other. In the example shown in FIG. 43A, the edge has a rectangular shape. Therefore, the sides ED1 and ED2 are sides parallel to each other. In the example shown in FIG. 43A, the sides ED1 and ED2 are rectangular short sides.

  The blade edge 51 is pressed against the inner surface SF1 at the position N1. Details of the position N1 will be described later. 42A, the blade tip 51 is pressed such that the projection PP of the blade tip 51 is disposed between the side ED1 and the side portion PS on the inner surface SF1 of the CF substrate 11 with reference to FIG. The side PS is arranged between the protrusion PP and the side ED2.

  Next, a plurality of trench lines TL (two lines in the drawing) are formed on the inner surface SF1. The formation of the trench line TL is performed between the position N1 (first position) and the position N3. A position N2 (second position) is located between the positions N1 and N3. Therefore, trench line TL is formed between positions N1 and N2 and between positions N2 and N3. The positions N1 and N3 may be located away from the edge of the inner surface SF1 of the CF substrate 11, or one or both of them may be located at the edge of the inner surface SF1. The formed trench line TL is separated from the edge of the CF substrate 11 in the former case, and is in contact with the edge of the CF substrate 11 in the latter case. Of the positions N1 and N2, the position N1 is closer to the side ED1, and the position N2 of the positions N1 and N2 is closer to the side ED2. In the example shown in FIG. 43A, the position N1 is close to the side ED1 of the sides ED1 and ED2. The position N2 is close to the side ED2 of the sides ED1 and ED2, but both the positions N1 and N2 may be located near either one of the sides ED1 or ED2.

  When the trench line TL is formed, in the present embodiment, the blade edge 51 is displaced from the position N1 to the position N2, and is further displaced from the position N2 to the position N3. That is, with reference to FIG. 42A, the blade edge 51 is displaced in the direction DA that is the direction from the side ED1 toward the side ED2. The direction DA corresponds to a direction in which the axial direction AX extending from the blade edge 51 is projected onto the inner surface SF1. In this case, the blade edge 51 is dragged on the inner surface SF <b> 1 by the shank 52.

  Next, the crackless state (FIG. 8A) described in Embodiment 1 is maintained over a desired time. Meanwhile, the CF substrate 11 and the TFT substrate 12 (not shown) are attached as described in the first to fifth embodiments.

  Referring to FIG. 43B, after the trench line TL is formed, the CF substrate 11 in the thickness direction DT extends from the position N2 toward the position N1 along the trench line TL (see the broken line arrow in the figure). The crack line CL is formed by extending the cracks. Formation of the crack line CL is started when the assist line AL and the trench line TL intersect each other at the position N2. For this purpose, the assist line AL is formed after the trench line TL is formed. The assist line AL is a normal scribe line with a crack in the thickness direction DT. The method of forming the assist line AL is not particularly limited, but may be formed using the edge of the inner surface SF1 as a base point as shown in FIG.

  Note that the crack line CL is less likely to be formed in the direction from the position N2 to the position N3 than in the direction from the position N2 to the position N1. That is, the ease of extension of the crack line CL has a direction dependency. Therefore, the phenomenon that the crack line CL is formed between the positions N1 and N2 but not between the positions N2 and N3 may occur. This embodiment is intended to divide the CF substrate 11 along the positions N1 and N2, and is not intended to separate the CF substrate 11 along the positions N2 and N3. Therefore, while it is necessary to form the crack line CL between the positions N1 and N2, the difficulty of forming the crack line CL between the positions N2 and N3 is not a problem.

  Next, the CF substrate 11 is divided along the crack line CL. Specifically, a break process is performed. If the crack line CL is completely advanced in the thickness direction DT when the crack line CL is formed, the formation of the crack line CL and the division of the CF substrate 11 may occur at the same time. In this case, the break process can be omitted.

  Thus, the CF substrate 11 is divided.

  Next, the 1st-3rd modification of the said dividing method is demonstrated below.

  Referring to FIG. 44A, the first modified example relates to a case where the intersection of the assist line AL and the trench line TL is insufficient as a trigger for starting the formation of the crack line CL (FIG. 43B). Is. Referring to FIG. 44B, an external force that generates a bending moment or the like is applied to the CF substrate 11 so that a crack in the thickness direction DT extends along the assist line AL. As a result, the CF substrate 11 is separated. Is done. Thereby, formation of the crack line CL is started. In FIG. 44A, the assist line AL is formed on the inner surface SF1 of the CF substrate 11. However, the assist line AL for separating the CF substrate 11 may be formed on the outer surface SF2 of the CF substrate 11. Good. In this case, the assist line AL and the trench line TL intersect each other at the position N2 in the planar layout, but do not directly contact each other. In this case, unlike the first embodiment, the end of the trench line TL of the CF substrate 11 does not need to be exposed.

  Further, in the first modified example, the separation of the internal stress in the vicinity of the trench line TL is released by the separation of the CF substrate 11, thereby starting the formation of the crack line CL. Therefore, the assist line AL itself may be a crack line CL formed by applying stress to the trench line TL.

  Referring to FIG. 45, in the second modification, the blade edge 51 is pressed against the inner surface SF1 of the CF substrate 11 at the position N3. When the trench line TL is formed, in the present modification, the blade edge 51 is displaced from the position N3 to the position N2, and is further displaced from the position N2 to the position N1. That is, with reference to FIG. 42, the blade edge 51 is displaced in a direction DB that is a direction from the side ED2 toward the side ED1. The direction DB corresponds to a direction opposite to the direction in which the axial direction AX extending from the blade edge 51 is projected onto the inner surface SF1. In this case, the blade edge 51 is pushed forward on the inner surface SF <b> 1 by the shank 52.

  Referring to FIG. 46, in the third modified example, when trench line TL is formed, cutting edge 51 is pressed against inner surface SF1 of CF substrate 11 with a greater force at position N2 than at position N1. . Specifically, the load on the blade edge 51 is increased when the position of the trench line TL reaches the position N4 with the position N4 as the position between the positions N1 and N2. In other words, the load on the trench line TL is increased between the positions N4 and N3, which are the end portions of the trench line TL, as compared with the position N1. Thereby, formation of the crack line CL from the position N2 can be easily induced while reducing a load at a portion other than the terminal portion.

  According to the present embodiment, the crack line CL can be more reliably formed from the trench line TL.

  Further, unlike the seventh embodiment described later, in the present embodiment, the assist line AL has not yet been formed at the time when the trench line TL is formed (FIG. 43A). Therefore, the crackless state can be maintained more stably without being affected by the assist line AL. If the stability in the crackless state does not matter, the crack in the state of FIG. 43A where the assist line AL is formed instead of the state of FIG. 43A where the assist line AL is not formed. The less state may be maintained.

(Embodiment 7)
A method for manufacturing the liquid crystal display panel in the present embodiment will be described below with reference to FIGS.

  Referring to FIG. 47, in the present embodiment, assist line AL is formed before formation of trench line TL. The method of forming the assist line AL is the same as that in FIG. 43B (Embodiment 6).

  Referring to FIG. 48, next, the blade edge 51 is pressed against the inner surface SF1, and the trench line TL is formed. The formation method itself of the trench line TL is the same as that in FIG. 43A (Embodiment 6). The assist line AL and the trench line TL intersect each other at the position N2. Next, as described in the first to fifth embodiments, the CF substrate 11 and the TFT substrate 12 (not shown) are attached.

  Referring to FIG. 49, next, the CF substrate 11 is separated along the assist line AL by a normal break process in which an external force that generates a bending moment or the like is applied to the CF substrate 11. Thereby, formation of the crack line CL (FIG. 8B) is started (see the broken line arrow in the figure). 47, the assist line AL is formed on the inner surface SF1 of the CF substrate 11. However, the assist line AL for separating the CF substrate 11 may be formed on the outer surface SF2 of the CF substrate 11. In this case, the assist line AL and the trench line TL intersect each other at the position N2 in the planar layout, but do not directly contact each other.

  The configuration other than the above is almost the same as the configuration of the sixth embodiment described above.

  Referring to FIG. 50, in the modification, when the trench line TL is formed, the blade edge 51 is pressed against the inner surface SF1 of the CF substrate 11 with a greater force at the position N2 than at the position N1. Specifically, the load on the blade edge 51 is increased when the position of the trench line TL reaches the position N4 with the position N4 as the position between the positions N1 and N2. In other words, the load on the trench line TL is increased between the positions N4 and N3, which are the end portions of the trench line TL, as compared with the position N1. Thereby, formation of the crack line CL from the position N2 can be easily induced while reducing a load at a portion other than the terminal portion.

(Embodiment 8)
Referring to FIG. 51A, in the method of manufacturing the liquid crystal display panel according to the present embodiment, trench line TL reaching position ED2 from position N1 via position N2 is formed. Next, the crackless state (FIG. 8A) described in Embodiment 1 is maintained over a desired time. Meanwhile, the CF substrate 11 and the TFT substrate 12 (not shown) are attached as described in the first to fifth embodiments.

  Referring to FIG. 51B, next, a stress is applied between position N2 and side ED2 so as to release the distortion of internal stress in the vicinity of trench line TL. This induces the formation of crack lines along the trench line TL.

  Specifically, as the application of stress, the pressed blade edge 51 is slid on the inner surface SF1 between the position N2 and the side ED2 (a region between the broken line and the side ED2 in the drawing). This sliding is performed until the side ED2 is reached. The cutting edge 51 is preferably slid so as to intersect the track of the trench line TL formed first, and more preferably to overlap the track of the trench line TL formed first. The length of this second sliding is, for example, about 0.5 mm.

  As a modification, in order to apply a stress between the position N2 and the side ED2, a laser beam is irradiated between the position N2 and the side ED2 on the inner surface SF1 instead of the sliding of the cutting edge 51 described above. May be. Due to the thermal stress generated thereby, the distortion of the internal stress in the vicinity of the trench line TL is released, thereby inducing the start of formation of the crack line.

  The configuration other than the above is almost the same as the configuration of the sixth embodiment described above.

(Embodiment 9)
Referring to FIG. 52A, in the method of manufacturing the liquid crystal display panel in the present embodiment, the blade edge 51 is displaced from the position N1 to the position N2, and further to the position N3, thereby moving away from the edge of the inner surface SF1. A trench line TL is formed. The method of forming the trench line TL itself is almost the same as that in FIG. 43A (Embodiment 6).

  Next, the crackless state (FIG. 8A) described in Embodiment 1 is maintained over a desired time. Meanwhile, the CF substrate 11 and the TFT substrate 12 (not shown) are attached as described in the first to fifth embodiments.

  Referring to FIG. 52B, the same stress application as in FIG. 51B (Embodiment 8 or a modification thereof) is performed. This induces the formation of crack lines along the trench line TL.

  Referring to FIG. 53, as a modification of the process of FIG. 52A, in forming trench line TL, cutting edge 51 may be displaced from position N3 to position N2 and from position N2 to position N1.

  The configuration other than the above is almost the same as the configuration of the sixth embodiment described above.

(Embodiment 10)
Referring to FIGS. 54 (A) and (B), in each of the above embodiments, blade edge 51v may be used instead of blade edge 51 (FIGS. 42 (A) and (B)). The blade edge 51v has a conical shape having a vertex and a conical surface SC. The protruding part PPv of the blade edge 51v is constituted by a vertex. The side part PSv of the blade edge is configured along a virtual line (broken line in FIG. 54B) extending from the apex to the conical surface SC. Thereby, the side part PSv has a convex shape extending linearly.

  In Embodiments 6 to 10, the first and second sides of the edge of the substrate are rectangular short sides, but the first and second sides may be rectangular long sides. The shape of the edge is not limited to a rectangle, and may be a square, for example. Further, the first and second sides are not limited to being linear, and may be curved. In each of the above embodiments, the main surface of the substrate is flat, but the main surface of the substrate may be curved.

  In each of the above embodiments, in order to obtain a plurality of liquid crystal display panels, first, one cell substrate having a brittle substrate is divided into a plurality of parts, and then each part is further divided into a plurality of displays. A panel may be obtained. For example, a plurality of display panels may be obtained by first dividing the cell substrate into rectangular portions and then further dividing the rectangular portion so that the long side is divided.

  Moreover, although a glass substrate is used as a brittle substrate particularly suitable for the dividing method described above, the brittle substrate is not limited to a glass substrate, and for example, a sapphire substrate may be used.

  In the liquid crystal display panel manufacturing method described above, a CF substrate 11 provided with a color filter, a black matrix and an alignment film on a glass substrate, and a TFT substrate 12 provided with wiring, active elements, electrodes and an alignment film on the glass substrate, However, after the trench line is formed on the glass substrate, processing for providing a configuration as the CF substrate 11 or the TFT substrate 12 may be performed on the glass substrate.

  The present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

11 CF substrate (brittle substrate)
12 TFT substrate (brittle substrate)
20 Liquid crystal layer 21 Seal part 51, 51v Cutting edge 60 Table 61 Breaking rug 71 Break bar 72 Break roller 101 LCD panel (liquid crystal display panel)
AL assist line CL crack line ED1 side (first side)
ED2 side (second side)
N1 position (first position)
N2 position (second position)
SF1, SF3 inner surface (main surface)
SF2, SF4 Outer surface (main surface)
SL Scribe line TL Trench line PP, PPv Protrusion PS, PSv Side

Claims (4)

Providing a first brittle substrate having a first main surface and a second main surface opposite to the first main surface and having a thickness direction perpendicular to the first main surface;
Providing a second brittle substrate having a third main surface and a fourth main surface opposite to the third main surface;
Pressing the blade edge against the first main surface of the first brittle substrate;
Plastic deformation is generated on the first main surface of the first brittle substrate by sliding the blade edge pressed by the pressing step on the first main surface of the first brittle substrate. A step of forming a first trench line having a groove shape, wherein the step of forming the first trench line includes the step of forming the first brittle substrate directly under the first trench line. A crackless state that is continuously connected in a direction intersecting with one trench line is obtained, and after the step of forming the first trench line, Bonding the first brittle substrate and the second brittle substrate to each other so that the first main surface and the third main surface of the second brittle substrate face each other, In the step of bonding the first brittle substrate and the second brittle substrate together, the first trench line formed in the first brittle substrate is at least partially covered by the second brittle substrate. And, after the step of bonding the first brittle substrate and the second brittle substrate together, cracks in the first brittle substrate in the thickness direction along the first trench line. A step of forming a first crack line by extending, wherein the first brittle substrate intersects the first trench line immediately below the first trench line by the first crack line; And the step of forming a second crack line on the fourth main surface of the second brittle substrate;
By warping the first brittle substrate and the second brittle substrate by locally applying a load on the second main surface of the first brittle substrate, the first crack line and the second Dividing the first brittle substrate and the second brittle substrate along each of the two crack lines,
A method for manufacturing a liquid crystal display panel.   The step of forming the second crack line is along the line where the second crack line is to be formed after the step of bonding the first brittle substrate and the second brittle substrate together. The manufacturing method of the liquid crystal display panel of Claim 1 performed by displacing a blade edge | tip on the said 4th main surface of a said 2nd brittle board | substrate.   The step of forming the second crack line includes the step of forming a second trench line having a groove shape by generating plastic deformation on the fourth main surface of the second brittle substrate. The manufacturing method of the liquid crystal display panel of Claim 1.   4. The method of manufacturing a liquid crystal display panel according to claim 3, wherein the step of forming the second trench line is performed before the step of bonding the first brittle substrate and the second brittle substrate together.

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