JP3277449B2 - Liquid crystal panel manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a liquid crystal panel. More particularly, the present invention relates to a multi-cavity technique for manufacturing a large number of liquid crystal panels simultaneously by cutting a plurality of empty cells after joining a pair of large-sized substrates to each other. More specifically, the present invention relates to a cutting technique for cutting out empty cells.

[0002]

2. Description of the Related Art A conventional method for manufacturing a liquid crystal panel by a multi-cavity method will be briefly described with reference to FIG. First, a pair of substrates 201 and 202 are prepared as shown in FIG. These substrates 201 and 202 have a large size and are divided into a plurality of sections in advance, and electrodes and the like are formed in advance. For example, a display array is formed for each section on one substrate 202, and includes pixel electrodes and switching elements for driving the pixel electrodes. On the other substrate 201, a counter electrode, a color filter corresponding to the display array, and the like are formed. For example, a seal pattern 204 is formed on the substrate 201 side corresponding to each section 203 by screen printing or the like. An opening 205 is formed in each seal pattern 204 in advance.
Next, as shown in (B), the two substrates 201 and 202 are overlapped with each other and joined via a seal pattern 204. Thereby, a plurality of empty cells 206 are formed. The inside of the empty cell 206 communicates with the outside through the opening 205. Subsequently, as shown in (C), the scribe line 20 is cut along the boundary of each empty cell 206 by a diamond cutter or the like.
Insert 7. The scribe line 207 is formed on both substrates 201 and 20.
2 are formed on the surface in the vertical and horizontal directions, respectively. The scribe line 207 is a so-called shaving line, which is cut very shallowly on the surfaces of the substrates 201 and 202 made of glass or the like. This scribing technique is basically the same as a method of cutting a normal glass plate with a diamond cutter. Finally, as shown in (D), mechanical pressure is applied along the scribe line to break the pair of substrates (break).
Then, the empty cells 206 are individually separated. After this the opening 20
Liquid crystal is injected into the empty cell 206 through the opening 5 and the opening 2 is opened.
05 is sealed. Note that one substrate has a seal pattern 2
The external connection terminal 208 is exposed outside the substrate 04.

[0003]

As described above, in the conventional method of manufacturing a liquid crystal panel, a substrate made of glass or the like is cut by scribing and breaking. However, the following problems to be solved occur in this process. I was First, when a mechanical pressure is applied along a scribe line to break a glass substrate, a large amount of static electricity is generated, and a switching element such as a thin film transistor included in a display array and a peripheral driving circuit are destroyed. A defect had occurred. Further, in the cutting of glass by scribing and breaking, the shape of the cut end face becomes irregular, so that the variation in the outer shape of the liquid crystal panel increases. For this reason, it becomes difficult to precisely position the liquid crystal panel in the inspection and the mounting stage in the post-process. In the worst case, a dimensional abnormality or chipping of the outer shape of the liquid crystal panel occurs at the time of a break, and the yield decreases. Further, if the width of the external connection terminal outside the seal pattern is short in the break after scribing, the glass is less likely to break. For this reason, in the conventional cutting using scribe and break, the width of the terminal usually needs to be secured at 1.5 mm or more, and the outer shape of the liquid crystal panel has been increased. As a result, the number of liquid crystal panels obtained from one large-size glass is reduced correspondingly, and the cost is low.

[0004]

The following means have been taken in order to solve the above-mentioned problems of the prior art. That is, the liquid crystal panel is manufactured by the following steps according to the present invention. First, a plurality of frame-shaped seal patterns having openings are formed on one substrate, and a protective seal pattern for preventing cutting water from entering is formed so as to include these seal patterns. Next, a joining step is performed, and the other substrate is joined to one substrate via the seal pattern to form empty cells having openings for each seal pattern, and a plurality of cells surrounded by the protective seal pattern are formed. Seal the empty cell from the outside. Further, a dicing process is performed, and both substrates are cut one by one along a boundary of each empty cell at a predetermined depth while supplying cutting water from the outside to form a separation groove. Subsequently, a dividing step is performed, pressure is applied along the separation groove to break both substrates, and the cells are separated into individual empty cells. Finally, an encapsulation step is performed to inject liquid crystal into the separated empty cells through the opening and seal the opening. As a characteristic matter, the dicing step is performed by an external
Relatively shallow separation groove on one substrate without connection terminals
And then the remaining one having terminals for external connection
A relatively deep isolation groove is formed in the substrate.

More specifically, the step of forming the seal pattern forms a protective seal pattern having an air hole in at least one place, and the step of joining includes bonding the two substrates in such a manner that the internal air can be discharged from the air hole. After joining, the air holes are sealed to seal a plurality of empty cells surrounded by the protective seal pattern .

According to the present invention, when a seal pattern is formed on the surface of one substrate by screen printing or the like, a protective seal pattern for preventing empty cells from entering cutting water during dicing along the outer periphery of the substrate. Provide. In this case, when the two substrates are heated and joined, the air inside can be exhausted to the outside,
Provide air holes in the protective seal pattern. Note that the number of protective seal patterns does not need to be one for one substrate.
Individual or three or more can be provided. In this case, each of the protective seal patterns except for at least one air hole is continuous with the sealing resin, and includes a plurality of empty cells. After bonding the pair of glass substrates, an adhesive resin or the like is applied to the air holes, and is cured by heating and sealing. Thereby, the empty cell inside is completely sealed from the outside. Subsequently, the first one of the two glass substrates bonded to each other is diced to a depth corresponding to, for example, about 30 to 90% of the substrate thickness to form a separation groove. The separation groove is not completely cut, and a part of the thickness of the substrate remains. The dicing is performed, for example, by using a grinding wheel that rotates at a high speed. In this case, cutting water for cooling and lubrication is supplied from the outside. Since the empty cells inside are sealed in advance by the protective seal pattern, there is no fear that even if a large amount of cutting water is supplied, the empty cells may enter the inside through the openings of the empty cells. After the separation groove is formed on one of the substrates in this manner, the separation groove is similarly formed on the remaining one of the substrates by dicing. After dicing, the remaining thickness of the substrate can be easily cut by applying mechanical pressure along the separation groove. In this way, individual empty cells can be separated with high accuracy. Here, the substrate to be diced and cut first has no terminal for external connection, and the substrate to be diced and cut last has the terminal formed. At this time, the depth of the separation groove is made larger in the last dicing cut than in the first dicing cut. This allows the substrate to be cut more efficiently.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of a liquid crystal panel manufacturing method according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a process chart of a liquid crystal panel manufacturing method according to the present invention. First, a pair of upper and lower substrates 1 and 2 are prepared as shown in FIG. Both substrates are made of, for example, large-sized glass of about several tens of cm square, and desired electrodes and the like are formed in advance for each of the divided sections. For example, a plurality of frame-shaped seal patterns 3 are formed on the lower substrate 2 corresponding to the above-described sections. For example, an ultraviolet curable resin or a thermosetting resin is screen-printed on the surface of the substrate 2 to form the seal pattern 3.
At this time, the opening 4 is left in a part of each seal pattern 3. At the same time, a protective seal pattern 5 for preventing cutting water from entering is formed along the outer periphery of the substrate 2 so as to include these seal patterns 3. In this example, one protective seal pattern 5 is formed so as to include all the seal patterns 3, but the present invention is not limited to this. Protective seal pattern 5 including at least several seal patterns 3
May be formed. The protective seal pattern 5 has an air hole 6 in at least one place.

Next, as shown in FIG. 1B, the upper substrate 1 is joined to the lower substrate 2 via the seal pattern 3. For example, when a thermosetting resin is used as the seal pattern 3, the substrates 1 and 2 are bonded together by heating and pressing. In the case of an ultraviolet curable resin, the substrates 1 and 2 are bonded to each other by irradiating ultraviolet rays in a pressurized state. At this time, the protective seal pattern 5 is also cured. When the two substrates 1 and 2 are joined, an empty cell 7 is formed for each seal pattern 3. The inside of the empty cell 7 surrounded by the seal pattern 3 communicates with the outside through the opening 4. However, all empty cells 7 are surrounded by the protective seal pattern 5 and can be sealed from the outside. In this bonding step, the inside air can be exhausted from the air holes 6 when heating is performed, so that the distance between the substrates 1 and 2 can be precisely controlled.

Next, the process proceeds to (C), after the two substrates 1 and 2 are joined, the air holes 6 are sealed to seal a plurality of empty cells 7 surrounded by the protective seal pattern 5. For example, a sealing material 8 made of an adhesive resin or the like is applied to the air holes 6 and cured by heating.

Proceeding to step (D), the two substrates 1 and 2 are cut one by one at a predetermined depth along the boundaries of the individual empty cells 7 while supplying cutting water from the outside to form separation grooves 9. . For example, the separation groove 9 is formed by dicing at a depth corresponding to about 30 to 90% of the thickness of the substrate without first fully cutting one of the two substrates bonded to each other. Dicing is performed while supplying cutting water for cooling and lubrication using, for example, a rotary grinding wheel. In addition, the other substrate is also diced and cut. At this time, the empty cell 7 is
Therefore, there is no fear that the cutting water enters the empty cell 7 through the opening 4 because it is completely sealed from the outside. As described above, the present invention is characterized in that instead of the conventional glass cutting method such as scribing / breaking, cutting is performed by dicing without cutting water entering empty cells.

Finally, in a step (E), a mechanical pressure is applied along the separation groove to break the remaining thickness of both substrates 1 and 2 to separate them into individual empty cells 7. Thereafter, liquid crystal is injected into the empty cells 7 separated by the above-described dividing step through the openings 4 and the openings 4 are sealed. The liquid crystal panel is completed by this encapsulation process. In addition, a terminal 10 for external connection is provided on a portion of one substrate of the liquid crystal panel which is exposed outward from the seal pattern 3. As described above, in the present invention, the substrate is not completely cut by dicing, but the so-called half-cut is performed, and the thick portion of the substrate left in the separation groove is broken by applying mechanical pressure along the separation groove. ing. All separation grooves are cut in this manner.

FIG. 2 is a process chart showing a specific example of a dicing step and a dividing step which are main parts of the present invention. As shown in (A), first, a separation groove 9a is formed in one of the substrates 2 by dicing. This substrate 2 has no external connection terminals, and is hereinafter referred to as a counter substrate. The counter substrate 2 has a relatively shallow separation groove 9 having a depth of about 50% of the thickness of the substrate, for example.
a is formed. Next, as shown in FIG. 3B, after the upper and lower relations of the substrates are reversed, the other substrate 1 having the terminals 10 for external connection is formed with the separation grooves 9b by dicing in the same manner. In this case, a deep isolation groove 9b reaching, for example, about 90% of the thickness of the substrate is formed. Note that the substrate 1 on which the terminals 10 are formed is hereinafter referred to as a circuit substrate. Since the separation groove 9a on the counter substrate 2 side is relatively shallow, relatively high mechanical strength is maintained. Therefore, even if the relatively deep separation groove 9b is cut in the circuit board 1, there is no possibility that the empty cells 7 are individually separated at this stage. Conversely, first, the deep separation groove 9a is formed on the counter substrate 2 side.
Is formed, there is a problem in dicing when a separation groove is formed on the circuit board 1 side later. Finally, as shown in (C), mechanical pressure is applied along the separation grooves 9a and 9b to separate the cells into individual empty cells 7. At this time, since the separation groove 9b on the circuit board 1 side is deeply cut in advance, it can be broken very easily and accurately, and even if the width dimension of the terminal 10 exposed to the outside from the seal pattern 3 is reduced, as designed. And can be processed without breaking the yield. Further, since the break is performed after forming the separation groove in advance, the mechanical pressure is smaller than in the conventional scribing method, and the electrostatic breakdown on the circuit board side can be suppressed accordingly. Further, since dicing is performed in advance by a considerable thickness, the thickness of the break portion, which tends to have a relatively irregular end surface shape, is reduced, and the accuracy of the panel outer shape is improved accordingly.

Finally, an example of a liquid crystal panel manufactured according to the present invention will be described with reference to FIG. As shown
In the present liquid crystal panel, a circuit board 101 and a counter substrate 102 are joined to each other with a predetermined gap. Both substrates 10
A liquid crystal 103 is sealed in the gap between 1 and 102. Note that a seal pattern is omitted for ease of illustration.
The display array 104 is formed integrally on the inner surface of the circuit board 101. Further, a vertical drive circuit 105 and a horizontal drive circuit 106 are also integratedly formed around the display array 104. On the exposed upper end side of the circuit board 101, a terminal 107 for external connection is formed. This terminal 107
Are connected to a vertical drive circuit 105 and a horizontal drive circuit 106 via a wiring 108. On the other hand, although not shown, a counter electrode and a color filter are formed on the inner surface of the counter substrate 102 in some cases.

The display array 104 has row-like gate wirings 1.
09 and the column-shaped signal wiring 110 are formed by patterning. The gate wiring 109 is connected to the vertical drive circuit 105,
The signal wiring 110 is connected to the horizontal drive circuit 106.
A pixel electrode 111 and a switching element 112 are formed at each intersection of the gate wiring 109 and the signal wiring 110. The switching element 112 is formed of, for example, a thin film transistor. The gate electrode is connected to the gate wiring 109, the drain electrode is connected to the corresponding pixel electrode 111, and the source electrode is connected to the signal wiring 110.
Such a configuration is called an active matrix type.
Note that the present invention is not limited to the active matrix type liquid crystal panel, and it is needless to say that the present invention can be applied to a simple matrix type liquid crystal panel.

[0015]

As described above, according to the present invention, 2
When two glass substrates are bonded by a seal pattern, a protective seal pattern for preventing cutting water from entering is formed on the outer periphery of one of the substrates. The protective seal pattern is provided with air holes in advance, and after heating and joining the two substrates, the air holes are sealed to completely seal the empty cells inside from the outside. In this state, the separation groove is cut by so-called half cutting by dicing while supplying cutting water from the outside. At this time, since the empty cells inside are sealed by the protective seal pattern, there is no fear that the cutting water enters the inside of the empty cells. Thereafter, the relatively thin wall portion of the substrate left in the separation groove is broken by mechanical pressure. Compared to the conventional scribing method, in the present invention, since the glass substrate to be broken is thin, it can be separated into individual empty cells with a small mechanical pressure, and the electrostatic breakdown can be remarkably suppressed accordingly. In addition, since the thickness of the break portion, which tends to be a relatively irregular broken shape, is thin, the variation in the outer dimensions of the liquid crystal panel is reduced by that amount, and the positioning operation and the positioning operation in the subsequent process are facilitated. Further, since the variation in the panel outer dimensions is reduced, the yield is improved. Further, the size of the terminal exposed to the outside from the seal pattern can be suppressed to 1 mm or less, and the size and weight of the liquid crystal panel can be reduced. Also, since the size of the panel can be reduced,
The number of panels taken from large format glass is increased, and the cost is improved.

[Brief description of the drawings]

FIG. 1 is a process chart showing a liquid crystal panel manufacturing method according to the present invention.

FIG. 2 is a process diagram showing an example of a dicing process which is a main part of the liquid crystal panel manufacturing method according to the present invention.

FIG. 3 is a schematic perspective view showing an example of a liquid crystal panel manufactured according to the present invention.

FIG. 4 is a process chart showing an example of a conventional liquid crystal panel manufacturing method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Substrate 3 Seal pattern 4 Opening 5 Protective seal pattern 6 Air hole 7 Empty cell 8 Sealing material 9 Separation groove 10 Terminal

Continuation of front page (56) References JP-A-5-232422 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1/13 101 G02F 1/1341

Claims (2)

(57) [Claims] A step of forming a plurality of frame-shaped seal patterns having openings on one substrate and forming a protective seal pattern for preventing cutting water from entering so as to include the seal patterns; Joining the other substrate to one substrate via a seal pattern to form empty cells having an opening for each seal pattern, and sealing a plurality of empty cells surrounded by the protective seal pattern from the outside A dicing step of cutting both substrates one by one along a boundary of each empty cell at a predetermined depth while supplying cutting water from the outside to form a separation groove, and applying a pressure along the separation groove. A liquid crystal panel manufacturing method comprising: a dividing step of breaking both substrates and separating the cells into individual empty cells; and a sealing step of injecting liquid crystal into the separated empty cells through an opening and sealing the opening . , Serial dicing step, pieces no terminals for external connection
A relatively shallow isolation groove is formed in the other substrate, and then external connection
A relatively deep separation groove on the other substrate with terminals for
A method for manufacturing a liquid crystal panel, comprising: 2. The forming step includes forming a protective seal pattern having an air hole in at least one place, and the joining step includes joining the two substrates in a state where internal air can be discharged from the air hole, and then forming the air hole. 2. The method according to claim 1, wherein a plurality of empty cells surrounded by the protective seal pattern are sealed.