JP7287637B2 - Liquid crystal panel manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a liquid crystal panel in which a pair of glass substrates are bonded together, and more particularly to a liquid crystal panel capable of simplifying wiring and saving space.

Since the liquid crystal panel to which the pair of glass substrates are bonded is not driven by itself, it is connected to an external circuit such as a drive control circuit to control its operation. Generally, a liquid crystal panel and an external circuit are connected by a flexible cable. There are methods such as COG (chip-on-glass) for connecting a flexible cable to a liquid crystal panel, and more efficient connection methods are being developed.

However, the presence of flexible cables still hinders thinning and miniaturization. Further, in mobile electronic devices such as smartphones, there is a demand for a narrower frame of the display, and even with the narrower frame, flexible cables and external circuits have sometimes become a problem.

Therefore, there is a display panel in which through holes are formed in terminal portions extending from a display area to connect terminals of the display panel to an external circuit or the like (see, for example, Patent Document 1). By filling the through-hole with a conductive member, it is possible to connect to an external circuit without using a flexible cable.

JP 2003-075859 A

A drill is used to form the through-holes in Patent Document 1. Drilling a glass substrate used for a liquid crystal panel has a high possibility of damaging the substrate. In particular, liquid crystal panels use thin substrates of about 0.1 to 0.5 mm, and it is difficult to drill through holes in such substrates.

A method of forming through-holes in a thin glass substrate by irradiating a laser is also conceivable, but there is a possibility that the heat of the laser may adversely affect the periphery of the through-holes. In other words, the metal circuit formed in the periphery of the laser irradiation area is melted by the heat from the laser, thereby destroying the electrode or generating debris due to laser ablation. Due to such problems, it is extremely difficult to form a through hole in the substrate.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal panel that can be connected to an external circuit without using wiring such as a flexible cable.

A liquid crystal panel according to the present invention includes at least an array substrate having a terminal portion and a color filter substrate arranged to face the array substrate with a liquid crystal layer interposed therebetween. The terminal portion has a groove formed in the thickness direction along the end face, and the conductive member is filled along the groove.

The conductive member formed on the terminal portion has the same function as the wiring cable by connecting to the circuit of the liquid crystal panel. In addition, filling the grooves with the conductive member reduces the influence on the dimensions of the liquid crystal panel, so that it is possible to provide a liquid crystal panel with a narrow frame. Furthermore, since the conductive portion is provided in the groove, the risk of the conductive portion being damaged can be reduced.

Further, in the liquid crystal panel according to the present invention, a groove may be formed in an area adjacent to the display section in addition to the terminal section. In this case, the groove is formed along the thickness direction on at least one end surface of the array substrate and the color filter substrate, and the conductive member is filled along the groove. Since a liquid crystal panel usually requires a plurality of control circuits, it is possible to make the layout of the circuits more compact by forming the grooves in the area adjacent to the display section as well.

Moreover, it is preferable that the circuit portion is arranged on the surface of the array substrate and the circuit portion is electrically connected to the conductive member. By providing the circuit section on the array substrate side, it is possible to further reduce the size of the liquid crystal panel.

Moreover, it is preferable that the groove is formed so as to penetrate all the way in the thickness direction. Forming the groove along the entire thickness direction facilitates the filling of the conductive member.

According to the present invention, it is possible to provide a liquid crystal panel capable of connecting the liquid crystal panel and an external circuit without using wiring.

It is a figure which shows schematic structure of the liquid crystal panel which concerns on one Embodiment of this invention. 4 is a schematic diagram of a liquid crystal panel according to another embodiment of the present invention; FIG. 1 is a diagram showing a schematic configuration of a multi-panel glass base material including a plurality of liquid crystal panels; FIG. It is a figure which shows the outline of the laser processing with respect to the glass base material for multi-facets. FIG. 3 is a diagram schematically showing modified lines formed in a glass base material for multi-panel production; It is a figure which shows the outline of the affixing of the protective film to the glass base material for multi-panels, and laser processing. It is a figure which shows an example of the etching apparatus applied to this invention. FIG. 5 is a diagram showing variations of etching processes applied to the present invention; FIG. 2 is a diagram showing an outline of cut grooves formed in a glass base material for multi-panel production; It is a figure which shows the outline of the peeling process of a protective film, and the parting process of a liquid crystal panel. It is a figure which shows the outline of the end surface in which the groove part was formed.

1A and 1B show a schematic configuration of a liquid crystal panel 10 according to one embodiment of the invention. As shown in the figure, the liquid crystal panel 10 is constructed such that an array substrate 12 and a color filter substrate 14 are bonded together with a liquid crystal layer 16 interposed therebetween. Glass substrates such as alkali-free glass are used for the array substrate 12 and the color filter substrate 14 . Since the configuration is the same as the configuration of the electrodes and the like formed on the array substrate 12 and the color filter substrate 14, description thereof is omitted here.

The array substrate 12 has electrode terminal portions 122 which are regions extending beyond the color filter substrate 14 . Metal wiring is formed on the main surface of the electrode terminal portion 122 on the color filter substrate 14 side. The metal wiring is electrically connected to electrodes and the like corresponding to the liquid crystal layer 16 .

A circuit section 19 is provided on the main surface of the array substrate 12 . The circuit unit 19 is configured to control signals from the outside and transmit them to the liquid crystal panel 10 . The circuit section 19 is a known integrated circuit board, and is electrically connected to the metal wiring of the electrode terminal section 122 by the end face electrodes 22 .

The end surface electrode 22 is a conductive member formed in the thickness direction on the end surface of the electrode terminal portion 122 . As an example of the end surface electrode 22, it can be formed using a copper paste. The end surface electrodes 22 are also partially formed on the main surface side of the array substrate 12 as shown in FIG.

A groove portion 24 is formed in the end face of the electrode terminal portion 122 to form the end face electrode 22 . The groove portion 24 is formed along the plate thickness direction on the end surface of the array substrate 12 . The groove portion 24 is a recess having a semicircular cross-sectional shape formed throughout the thickness direction of the array substrate 12 , and the recess is filled with a copper paste that will become the end surface electrode 22 . A coating device such as a syringe can be used to fill the copper paste. The width dimension of the groove portion 24 is determined by the resolution of the display portion, etc., and may be 10 μm or less. Since the edge electrodes 22 do not extend beyond the width of the grooves 24 , even if the pitch of the edge electrodes 22 is small, they can be formed without contacting adjacent edge electrodes 22 .

Next, another embodiment of the liquid crystal panel according to the present invention will be described with reference to FIG. FIG. 2 is a diagram showing the configuration of the liquid crystal panel 100 according to this embodiment. The configuration of the liquid crystal panel 100 is substantially the same as the configuration of the liquid crystal panel 10 shown in FIGS. It is A known ITO film, metal nanowires, organic conductive film, or the like can be used for the transparent thin film 18 . The transparent thin film 18 is formed for applications such as touch operation detection and electrostatic discharge (ESD), for example.

Grooves 24 are formed in the thickness direction at the ends of the array substrate 12 and the color filter substrate 14 . The grooves 24 are formed in the peripheral area of the image display section where the liquid crystal layer 16 is arranged, and are formed in the array substrate 12 and the color filter substrate 14 in the vertical direction. In addition, in this embodiment, for convenience of explanation, the groove portion 24 in which the end face electrode 22 is not formed is described.

An edge electrode 22 is formed in the groove 24 . The edge electrode 22 is configured to electrically connect the transparent thin film 18 and the circuit portion 19 provided on the main surface of the array substrate 12 . The edge electrodes 22 can be formed by filling the grooves 24 with copper paste as described above.

By forming the end face electrodes 22, it is possible to connect the electrode circuits of the liquid crystal panel and the external circuit without using flexible cables, etc., so that it is not necessary to consider cable routing, etc., and the liquid crystal panel can be It is possible to reduce the size of the display and narrow the frame.

Next, an example of a method for manufacturing the liquid crystal panel 10 will be described. As shown in FIGS. 3(A) and 3(B), the liquid crystal panel 10 is generally manufactured as a multi-panel glass base material 50 including a plurality of such panels, and the multi-panel glass base material 50 is divided. By doing so, a single liquid crystal panel 10 is obtained. In this embodiment, for the sake of convenience, the processing of the multi-panel glass base material 50 in which six liquid crystal panels 10 are arranged in a matrix of three rows and two columns will be described. The number of 10 can be increased or decreased as appropriate. A transparent thin film 18 is formed on the main surface of the multi-panel glass base material 50 .

In order to remove the liquid crystal panel 10 from the multi-panel glass base material 50, first, as shown in FIGS. 4A and 4B, the multi-panel glass base material 50 is irradiated with a laser beam. A reforming line 20 is thus formed. In this embodiment, the modified line 20 is formed while the transparent thin film 18 is being removed along the planned shape cutting line corresponding to the contour shape of the liquid crystal panel 10 .

In addition, concave modified portions 201 are formed at positions corresponding to the grooves 24 as well as along the intended shape cutting lines of the liquid crystal panel 10 . The concave modified portion 201 can be formed by irradiating a laser beam in the same manner as the modified line 20. The transparent thin film 18 is removed so as to be continuous with the planned shape cutting line, and the array substrate 12 and the array substrate 12 are formed. It is formed on the color filter substrate 14 . In this embodiment, the concave modified portions 201 are formed in the array substrate 12 and the color filter substrate 14 in order to form the groove portions 24 in the regions adjacent to the display portion. When forming the groove portion 24 , the concave modified portion 201 may be formed only on the array substrate 12 .

The modified line 20 (hereinafter, unless otherwise specified, the modified line 20 includes the concave modified portion 201) is, for example, a light beam pulse ( It is a filament array in which a plurality of filament layers formed by a beam diameter of about 1 to 5 μm are arranged. In this embodiment, the reforming line 20 has a plurality of through holes or cracks formed in the plate thickness direction as shown in FIG. 5(A). The reforming line 20 has a property of being etched more easily than other portions of the multi-panel glass base material 50 . Of course, the shape of the reforming line 20 is not limited to such a shape, and any shape that is easy to etch may be used.

The light beam from the pico laser has a depth of focus greater than the range that includes at least both the array substrate 12 and the color filter substrate 14 . Therefore, the modified lines 20 for dividing the liquid crystal panel 10 are simultaneously formed on both the array substrate 12 and the color filter substrate 14 . In principle, both the array substrate 12 and the color filter substrate 14 can be processed by one laser at the same time. After forming the modified lines 20 only on the substrate 12, the modified lines 20 may be formed only on the color filter substrate 14 from the side of the color filter substrate 14 (see FIGS. 5B and 5C). . By performing such processing, the number of man-hours required for laser scanning is increased, but the occurrence of problems in the liquid crystal layer 16 can be easily suppressed. Forming the modification lines 20 along the entire thickness direction of the array substrate 12 and the color filter substrate 14 facilitates the dividing process. It is also possible to appropriately adjust the formation area of the quality line 20 .

As shown in FIG. 6A, after forming the modified lines 20, both main surfaces of the multi-panel glass base material 50 are covered with protective films 26. As shown in FIG. The protective film 26 has resistance to at least an etchant, which will be described later, and serves to protect the multi-panel glass base material 50 and the transparent thin film 18 . Here, polyethylene having a thickness of 50 to 75 μm is used as the protective film 26 . However, the configuration of the protective film 26 is not limited to this. For example, materials such as polypropylene, polyvinyl chloride, and olefin-based resins, which are resistant to an etchant used to etch glass, can be appropriately selected and employed.

When the attachment of the protective film 26 is completed, subsequently, the protective film 26 is scanned with a laser beam along the area where the modified line 20 is formed, as shown in FIG. 6(B). The scanning of this laser beam removes the protective film 26 in the region where the modified line 20 is formed. Then, an opening is formed in the protective film 26, and as a result, as shown in FIG. become.

In this embodiment, the protective film 26 is adhered and patterned after the modified lines 20 are formed, but the present invention is not limited to this order. For example, patterning of the protective film 26 may be performed simultaneously with formation of the modified lines 20 after the protective film 26 is attached to the multi-panel glass base material 50 . In this case, it is necessary to adjust the power, focal length, etc. of the laser beam so that the glass substrate can be sufficiently reformed in the curved area while removing the protective film 26 .

After the protective film 26 has been scanned with the laser, as shown in FIG. 7, the multi-panel glass base material 50 is introduced into an etching apparatus 300 and etched with an etchant containing hydrofluoric acid, hydrochloric acid, or the like. . In the etching apparatus 300, the multi-panel glass base material 50 is conveyed by the carrying rollers, and the etching liquid is brought into contact with one or both surfaces of the multi-panel glass base material 50 in the etching chamber. An etching process for 50 is performed. A cleaning chamber for washing away the etchant adhering to the multi-panel glass base material 50 is provided in the subsequent stage of the etching chamber in the etching apparatus 300. It is discharged from the etching apparatus 300 in a state where it is detached.

As an example of a method of bringing the etchant into contact with the multi-panel glass base material 50, as shown in FIG. and spray etching. Alternatively, instead of spray etching, as shown in FIG. 8B, in an overflow type etching chamber 304, a configuration may be employed in which the multi-panel glass base material 50 is conveyed while being in contact with the overflowing etchant. is also possible.

Further, as shown in FIG. 8(C), dip etching is employed in which one or a plurality of multi-panel glass preforms 50 housed in a carrier are immersed in an etching tank 306 containing an etchant. is also possible.

In any case, it is important to prevent the regions in which the modified lines 20 are formed from penetrating in the thickness direction during the etching process, so that the multi-panel glass base material 50 is not divided. be. If part of the modified line 20 penetrates the array substrate 12 or the color filter substrate 14 during the etching process, the etchant will enter the inside of the liquid crystal panel 10 . Therefore, during the etching process (particularly in the latter half of the etching process), it is necessary to slow down the etching rate and accurately control the etching amount. In this embodiment, thin hydrofluoric acid of 2% by weight or less is used to progress the etching process at a slow speed of 10 μm/min or less, but the method is not limited to this method.

Rather than slowing down the etching rate throughout the etching process, it is possible to shorten the etching process time by adopting a faster etching rate at first and slowing it down step by step. For example, it is preferable to employ a configuration in which the concentration of hydrofluoric acid in the etching solution is gradually decreased within a range of about 1 to 10% by weight as the etching apparatus 300 proceeds to the later stage.

When the multi-panel glass base material 50 passes through the etching device 300, the reforming lines 20 are etched. Therefore, even if scratches or the like have occurred during laser irradiation, the scratches can be easily removed. In addition, since the etchant permeates the reforming line 20 faster than other locations, the amount of etching is greater in the depth direction of the glass substrate than in the width direction. FIG. 9 shows a cross section of the kerf 28 formed by the etching process. The cut groove 28 is formed by etching the region where the modified line 20 is formed.

The cut groove 28 has a large aspect ratio in the depth direction with respect to the width direction, unlike a groove formed by a normal etching process. Therefore, the cut grooves 28 can be formed without affecting the liquid crystal panel 10 even in the multi-panel glass base material 50 in which the liquid crystal panels are adjacent to each other. The cut groove 28 is formed in the array substrate 12 or the color filter substrate 14 so as not to penetrate completely in the plate thickness direction. At this time, it is preferable to adjust the thickness of the lower portion of the cut groove 28 to 100 μm or less. If the plate thickness of the unetched portion exceeds 100 μm, it may become difficult to divide the liquid crystal panel 10 in the later-described dividing process.

The protective films 26 are removed from both main surfaces of the etched multi-panel glass base material 50 . When removing the protective film 26 , at one of the four corners of the multi-panel glass base material 50 , the protective film 26 is lifted using a physical force, and then the protective film 26 is removed from the multi-panel glass base material 50 . It can be easily peeled off by pulling it in the diagonal direction (see FIG. 10(A)).

The multi-panel glass base material 50 from which the protective film 26 has been peeled off forms a groove for terminal cutting in order to remove the color filter substrate 14 in the region facing the electrode terminal portion 122 . The terminal cutting grooves are formed by scanning a known scribing wheel along the color filter substrate 14 .

After forming the terminal cutting grooves, the liquid crystal panel 10 is separated from the multi-panel glass base material 50 . By applying a mechanical stress to the cut grooves 28 and the terminal cutting grooves, cracks progress vertically from the bottom of the cut grooves 28, and the liquid crystal panel 10 is divided along the intended shape cutting lines. Further, by applying stress to the terminal cutting grooves in the same manner as the liquid crystal panel 10 is divided, a portion of the color filter substrate 12 in the region facing the electrode terminal portions 122 can be removed. If there is a risk that cracks may develop in an unexpected region during division, the liquid crystal panel 10 may be divided using an ultrasonic cutting tool.

FIGS. 11A and 11B show schematic configurations of end surfaces of the liquid crystal panel 10 after division. FIG. 11A shows the end surface of the liquid crystal panel 10 after being cut. An end surface of the liquid crystal panel 10 has an inclined portion 80 and a vertical portion 82 . The inclined portion 80 is an end face region that is inclined outward from the main surfaces of the array substrate 12 and the color filter substrate 14 . The inclined portion 80, for example, reduces the taper widths (L1 and L2 in FIG. 11A) generated on the end surfaces of the array substrate 12 and the color filter substrate 14, each having a thickness of about 0.15 mm to 0.25 mm. , 50 μm or less (mostly 20 to 35 μm). By controlling the taper width in such a manner, the influence of side etching hardly occurs, so that it is possible to design the multi-panel glass base material 50 in which the liquid crystal panels 10 are arranged close to each other. For example, if the laser width is 2 μm+α and there is a total gap of about 10 μm, the multi-panel glass base material 50 can be properly separated into the single liquid crystal panels 10 .

As shown in FIG. 11B, grooves 24 are formed in the end faces of the liquid crystal panel 10 by etching the concave modified portions 201 . The groove portion 24 is formed so as to taper from the surface portion toward the central portion by being etched. In addition, since etching is not performed over the entire thickness direction, the groove 24 is not formed in the central portion in the thickness direction. Even in this state, it is possible to form the end face electrodes 22 by filling copper paste along the formation direction of the grooves 24 .

If necessary, by irradiating the groove 24 of the liquid crystal panel 10 after division with a laser, it is possible to remove the glass substrate remaining in the central portion and allow the groove 24 to penetrate in the plate thickness direction. Since the amount of the glass substrate removed by this laser irradiation is very small, there is almost no possibility that the peripheral portion will be affected by heat. Further, since the central portion where the glass substrate should be removed is the vertical portion 82 protruding from the inclined portion 80, it is easy to irradiate the laser. Forming the grooves 24 over the entire thickness direction of the liquid crystal panel 10 further facilitates the formation of the end face electrodes 22 .

The circuit section 19 can be arranged at desired timing in a post-process. After the circuit section 19 is provided, it is electrically connected to the end surface electrode 22 and further connected to the lead wiring of the liquid crystal panel 10, thereby manufacturing the liquid crystal panel.

In the above-described embodiment, the protective film 26 is used to protect the transparent thin film 18, but in the mode in which the transparent thin film 18 is not formed, the protective film 26 is not necessarily attached. In that case, after forming the modified lines 20 in the desired regions, the glass base material 50 for multi-panel formation may be etched. Although the thickness of the multi-panel glass base material 50 is reduced as a whole, no particular problem occurs in the liquid crystal panel 10. Therefore, by dividing the liquid crystal panel 10 by the above-described method, the liquid crystal panel 10 can be obtained. manufactured.

The description of the above-described embodiments should be considered illustrative in all respects and not restrictive. The scope of the invention is indicated by the claims rather than the above-described embodiments. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and range of equivalents of the claims.

10-liquid crystal panel 12-array substrate 14-color filter substrate 16-liquid crystal layer 18-transparent thin film 20-modification line 22-end surface electrode 24-groove 122-electrode terminal

Claims (4)

an array substrate having a terminal portion;
a color filter substrate arranged to face the array substrate with a liquid crystal layer interposed therebetween;
A liquid crystal panel comprising at least
The terminal portion has a groove formed in the thickness direction along the end face,
In the method for manufacturing a liquid crystal panel, characterized in that a conductive member is filled along the groove,
By irradiating a laser beam to the multi-panel glass base material for multi-panel cutting of the liquid crystal panel, the positions corresponding to the planned shape cutting lines of the liquid crystal panel and the grooves are easily etched continuously. modifying properties;
After the step of modifying, simultaneously etching the positions corresponding to the intended shape cutting lines of the liquid crystal panel and the grooves;
A liquid crystal panel manufacturing method comprising: an array substrate having a terminal portion;
a color filter substrate arranged to face the array substrate with a liquid crystal layer interposed therebetween;
wherein a groove is formed along the thickness direction in at least one end surface of the array substrate or the color filter substrate and adjacent to the display area,
In the method for manufacturing a liquid crystal panel, the conductive member is filled along the groove,
By irradiating a laser beam to the multi-panel glass base material for multi-panel cutting of the liquid crystal panel, the positions corresponding to the planned shape cutting lines of the liquid crystal panel and the grooves are easily etched continuously. modifying properties;
After the step of modifying, simultaneously etching the positions corresponding to the intended shape cutting lines of the liquid crystal panel and the grooves;
A liquid crystal panel manufacturing method comprising: A circuit part is arranged on the surface of the array substrate,
3. The method of manufacturing a liquid crystal panel according to claim 1, wherein the circuit section is electrically connected to the conductive member. 4. The method of manufacturing a liquid crystal panel according to claim 1, wherein the groove is formed so as to penetrate all the way in the thickness direction.

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