JP2018016518A - Production method of thin glass substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of a glass substrate which can stably be made thin.SOLUTION: A production method of a thin glass substrate is a method for producing a thin glass substrate which can be applied to a flat panel display, and includes at least a masking step, a thinning step, a filling step, a groove formation step, and a separation step. The masking step is a step to mask an unused region of a liquid crystal panel 10 which has a used region positioned on a center part and the unused region on the periphery of the used region. The etching step is a step to make the used region thin by etching an etching panel 10 in a state in which the unused region is masked. The filling step is a step to fill the etched used region with a filler 44. The separation step is a step to separate the unused region from the used region in a state in which the used region is filled with the filler 44.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for manufacturing a thin glass substrate applied to a flat panel display, and more particularly to a method for manufacturing a glass substrate capable of stably performing a thinning process.

  Flat panel displays such as liquid crystal displays using glass substrates are used not only in electronic devices such as televisions and personal computers, but also in the fields of portable electronic devices such as smartphones and tablets. In these fields, further downsizing of products is required, and flat panel displays are also required to be thin.

  As a method of manufacturing a thin display, a display is manufactured using a glass substrate formed in a desired thickness in advance, and a display is manufactured up to a semi-finished product, and the glass substrate is processed to a desired thickness in a later process. There is a method of reducing the thickness. However, in the former method, it is possible to form a glass substrate thinned to about 100 μm, but there may be inconveniences when processing the glass substrate in the manufacturing process. For example, in a flat panel display manufacturing process, a process of applying a stress to the glass substrate in a process of forming a functional film or the like on the main surface of the glass substrate is required, so that a thin glass substrate may have insufficient strength.

  In the latter method, a wet etching process using a chemical solution mainly using hydrofluoric acid is employed. The wet etching process can be roughly divided into a dip method and a single wafer method. The dipping method is a method in which a glass substrate is immersed in an etching solution to perform an etching process. Single-wafer etching is a method in which an etching solution is sprayed onto a glass substrate conveyed in a certain direction using a spray nozzle or the like.

  Although it is possible to reduce the thickness of the glass substrate by any of the methods, the glass substrate that has been reduced to about 100 μm is reduced in strength and cracked during the etching process. It was difficult to handle. In particular, in recent years, a large glass substrate is often used to improve production efficiency, and the larger the glass substrate, the higher the risk that the glass substrate will be damaged during the etching process.

  Therefore, among the prior arts, there is a technique for reducing the thickness of the glass substrate to 100 μm or less by performing etching after securing the strength of the glass substrate by providing a rib whose masking edge is masked (for example, patents). Literature 1.). If this technology is used, the overall strength of the glass substrate can be maintained due to the thickness of the ribs even if the entire glass substrate is thinned, and the glass substrate can be handled during and after the etching process. In some cases, the glass substrate is less likely to break.

JP 2010-173869 A

  Although the above method is disclosed for reducing the thickness of the glass substrate, there is little mention of the post-process. In particular, since the rib is a region that cannot be used as a product, it must be separated from the thinned region. However, it is not easy to separate a glass substrate having a thickness of about 100 μm. The separation by the laser may damage the glass substrate due to the thermal shock from the laser. In addition, the scribe break may cause the glass substrate to be stressed too much and break. Furthermore, since the thinned region falls when the rib is separated, it is necessary to prepare a jig or the like for supporting the thinned region. In particular, when a large glass substrate is used, there is a high possibility that the glass substrate will be broken during the cutting, and there may be a problem in the separation work after the thinning process.

  The objective of this invention is providing the manufacturing method of the glass substrate which solves said problem and can perform a thinning process stably.

  The method for producing a thin glass substrate according to the present invention is a method for producing a thin glass substrate applicable to a flat panel display, and includes at least a masking step, a thinning step, a filling step, and a separation step. The masking step is a process of masking a non-use area of the glass substrate having a use area located in the center and a non-use area around the use area. The use area is an area where the display module is formed as a semi-finished product, and the non-use area is an area that is not used as a display outside the use area. In the masking process, the unused area is covered with a protective member having at least etching resistance. The etching step is a process of thinning the use region by etching the glass substrate in a state where the non-use region is masked. The filling step is a step of filling the etched use area with a filler. The separation step is a process of separating the non-use area from the use area in a state where the filler is filled in the use area.

  According to the present invention, by filling the thinned area with the filler, the thinned area is protected by the filler when the unused area that is not used as a flat panel display product is separated from the used area. Therefore, it becomes possible to perform separation work safely.

  Moreover, it is preferable that a filler is filled until it becomes the same height as a non-use area | region. By filling the filler to the same height as the non-use area, the use area is prevented from falling when the use area is separated from the non-use area, or a jig that supports the use area is used during separation. You don't have to.

  Moreover, it is preferable that the non-use area is separated by an etching process. At this time, the filler has etching resistance, and it is necessary to form a groove so that the filler penetrates the peripheral edge of the filler before the etching process. By separating by the etching process, the glass substrate can be separated with almost no stress. In addition, since the use area is protected by the filler during the etching process, there is no adverse effect on the use area due to the etching. Furthermore, since minute scratches disappear from the divided end surfaces by etching, the strength of the glass substrate is also improved.

  According to this invention, it becomes possible to provide the manufacturing method of the glass substrate which can perform a thinning process stably.

It is a figure which shows the outline of a liquid crystal panel in one Embodiment of this invention. It is a figure which shows a patterning process. It is a figure shown about the etching of a liquid crystal panel. It is a figure shown about filling of the use area | region with the filler. It is a figure shown about formation of the groove part to a filler. It is a figure shown about the division | segmentation of a liquid crystal panel.

  1A and 1B are a liquid crystal panel 10 processed in one embodiment of the present invention. The liquid crystal panel 10 is a semi-finished product of a liquid crystal display in which a plurality of liquid crystal element formation regions 101 are formed at predetermined intervals. The liquid crystal element formation region 101 is a product region that finally becomes a liquid crystal display. In the manufacturing process of a liquid crystal display, a plurality of liquid crystal element forming regions are chamfered on a large glass substrate to improve production efficiency. The liquid crystal panel 10 includes a first glass substrate 12, a second glass substrate 14, a functional layer 16, a liquid crystal sealing material 18, and an outer peripheral sealing material 20. The first glass 12 and the second glass 14 are non-alkali glass and are disposed to face each other. The plate | board thickness of the 1st glass substrate 12 and the 2nd glass substrate 14 is 0.5 mm, and uses the glass substrate of the same dimension.

  The functional layer 16 is a layer in which known image forming elements such as an insulating layer, a transparent electrode layer, a thin film transistor, a liquid crystal element, and a color filter are stacked in the liquid crystal element formation region 101. The functional layer 16 is sandwiched between the first glass substrate 12 and the second glass substrate 14. The liquid crystal sealing material 18 seals the functional layer 16 to partition the liquid crystal element formation region 101. Further, the liquid crystal sealing material 18 joins the first glass substrate 12 and the second glass substrate 14 together. As the liquid crystal sealing material 18, it is preferable to use a known ultraviolet curable resin. The outer peripheral sealing material 20 is configured to join the first glass substrate 12 and the second glass substrate 14 at the peripheral edge of the liquid crystal panel 10. The outer peripheral sealing material 20 is sandwiched between the first glass substrate 12 and the second glass substrate 14 so that gas and moisture do not enter the liquid crystal display element region 101, and is formed at the peripheral portion of the liquid crystal panel 10. . As the outer peripheral sealing material 20, it is preferable to use an ultraviolet curable resin like the liquid crystal sealing material 18. The outer peripheral sealing material 20 may be omitted depending on the design of the liquid crystal panel 10.

  From here, the thinning process and the dividing process of the liquid crystal panel 10 will be described with reference to FIGS. The present embodiment includes a patterning step, an etching step, a filling step, a groove forming step, and a separation step. The patterning step will be described with reference to FIGS. 2 (A) and 2 (B). In the patterning step, the protective film 30 having acid resistance is covered on the peripheral surface and the end surface of the liquid crystal panel 10. As the protective film 30, a film having at least resistance to hydrofluoric acid is used. For example, it is preferable to use a film including a layer made of polymethylpentene, polypropylene, polyethylene, or polyvinyl chloride. The protective film 30 may be covered by applying the protective film 30 to the main surface of the liquid crystal panel 10 using an attaching device such as a laminating device, and then patterning to remove the protective film 30 from the central region. Alternatively, a protective film 30 (polymethylpentene is preferable) formed in a band shape may be attached in a U shape so as to cover the edge portions and end surfaces of both main surfaces of the liquid crystal panel 10. Further, besides the protective film 30, an acid resistant resin or the like may be applied for protection.

  The end surface of the liquid crystal panel 10 may be protected by applying an end surface sealing material 32 to the gap between the first glass substrate 12 and the second glass substrate 14. In this embodiment, the end surface is protected using the protective film 30 and the end surface sealing material 32. As the end surface sealing material 32, an ultraviolet curable resin or a thermosetting resin can be used. The protection of the end face is for preventing the outer peripheral sealing material 20 from being eroded by an acidic solution such as hydrofluoric acid, and appropriate protection is performed according to the etching processing time, the composition of the etching solution, and the like. The end surface sealing material 32 can be applied using a coating device such as a dispenser.

  The protective film 30 is coated on the outer side of at least the liquid crystal sealing material 18 disposed at the outermost part. Moreover, it is preferable to cover the center side of the outer peripheral sealing material 20. The area covered by the protective film 30 is an area that is not finally used as a component of the liquid crystal display, corresponds to a non-use area of the claims, and an area not covered by the protective film 30 is patented. This corresponds to the use area of the claims. The interval between the liquid crystal sealing material 18 and the outer peripheral sealing material 20 can be appropriately adjusted depending on the design of the liquid crystal panel 10.

  In the etching step, the use area is thinned by performing an etching process on the liquid crystal panel 10. In the etching process, the first glass substrate 12 and the second glass substrate 14 are thinned by bringing the liquid crystal panel 10 into contact with an etching solution containing at least hydrofluoric acid. As the etching means, a dip method or a single wafer method can be selected as appropriate. It is preferable to use at least hydrofluoric acid as the etching solution and use an inorganic acid such as hydrochloric acid or a surfactant. As an embodiment of the etching step, as shown in FIG. 3A, a plurality of spray nozzles 42 arranged in the vertical direction with respect to the liquid crystal panel 10 being conveyed in the direction indicated by the arrow by the conveying roller 40. A single-wafer etching method in which an etching solution is sprayed can be given.

  As shown in FIG. 4A, the liquid crystal panel 10 processed in the etching step is in a state where only the central portion of the liquid crystal panel 10 is thinned. The thickness of the central portion is preferably reduced to 150 μm or less, and more preferably to 100 μm or less. Usually, when the liquid crystal panel 10 is etched to 100 μm or less, the liquid crystal panel 10 may flutter or bend during transportation due to the weight of the glass substrate and the jetting of the etching solution. If a problem occurs during conveyance, the liquid crystal panel 10 may be damaged or fall from between the conveyance rollers 40. However, according to the present embodiment, since the region protected by the protective film 30 is not thinned, it is possible to perform the processing stably even during the etching process. According to

  Further, as shown in FIG. 3B, it is preferable that each side of the liquid crystal panel 10 is placed in an oblique direction with respect to the transport roller 40. By placing in this manner, the four sides of the liquid crystal panel 10 are always supported from below by the transport rollers 40 even during the etching process, so that the thinned liquid crystal panel 10 is bent and the space between the transport rollers 40 is increased. It is possible to further prevent falling.

  Although the liquid crystal panel 10 is divided after the etching step, a functional layer may be formed on the first glass substrate 12 or the second glass substrate 14 before the unused area is divided. In portable electronic devices and the like, an interface using a touch panel is used. However, an in-cell method or an on-cell method for providing a touch panel function to a flat panel display is employed in order to reduce the thickness. As described above, when a function other than the display function is imparted to the flat panel display, a functional layer such as a transparent conductive film may be formed before the dividing process. Although it is possible to form a functional film after separation of the non-use area, the thinned liquid crystal panel 10 may have reduced strength. Therefore, the function film should be formed before the non-use area is separated. As a result, the risk of damage to the liquid crystal panel 10 can be reduced.

  The protective film 30 is peeled off after the etching process. When the protective film 30 is peeled off, it can be peeled off by applying a physical force. In addition, if there is little influence in a post process, it is also possible to process a post process, with the protective film 30 covered. Since it is very difficult to remove the end surface sealing material 32, it is preferable to flow without removing.

  From here, the cutting process which divides the peripheral area | region which is not thinned from a center area | region is demonstrated. The separation process includes a filling step, a groove forming step, and a separation step. In the filling step, the filling material 44 is filled in the region thinned by the etching process. In this embodiment, paraffin having acid resistance (etching resistance) is used as the filler 44. Since the paraffin can be removed by being immersed in a peeling solution after the separation process, the peeling process can be performed without applying stress to the liquid crystal panel 10. In addition to paraffin, a photosensitive resin having acid resistance can be used as the filler 44. The photosensitive resin can also be peeled without applying stress to the liquid crystal panel 10 at the time of peeling after the dividing step.

  The filling material 44 is filled in both main surfaces of the liquid crystal panel 10 until the same height as the peripheral edges of the first glass substrate 12 and the second glass substrate 14 is reached. By filling the filling material 44 to the same height as the peripheral portion, it does not fall when the thin region is separated, and a jig or the like for supporting the thin region is not necessary. The filler 44 can be injected using a coating device such as a dispenser, a spin coater, or a slit coater. Further, since the application region is thin and concave, the filler 44 can be easily applied. The paraffin is cured by leaving it for a certain time in a room temperature environment after coating.

  After the filler 44 is cured, a groove 46 is formed on the peripheral edge of the filler 44 as shown in FIG. The groove 46 is a region formed so as to penetrate the filler 44 as shown in FIG. 5A and expose the first glass substrate 12 and the second glass substrate 14. As a means for forming the groove 46, it is preferable to use a laser. In particular, by using a pulse laser such as a pico laser, the groove 46 can be formed without damaging the glass substrate. The position where the groove 46 is formed is formed in a region outside the liquid crystal sealing material 18 arranged on the outermost part. The groove 46 only needs to have a width that allows the etching solution to contact the glass substrate. In the case where a photosensitive resin is used, the groove 46 can be formed by photolithography.

  After forming the groove 46, the liquid crystal panel 10 is etched to separate the non-use area from the use area. For the etching process, a single-wafer etching apparatus can be used as in the above-described etching step. Since the first glass substrate 12 and the second glass substrate 14 are exposed by the groove 46, they come into contact with the etching solution and separate the peripheral region of the liquid crystal panel 10. Since the separation work by the etching process is hardly stressed, the liquid crystal panel 10 is less likely to be damaged. Further, since the use area is protected by the filler 44, there is no possibility that the use area falls during separation. Since it is possible to remove fine scratches on the sectional surface by etching, the strength of the liquid crystal panel 10 is improved.

  In addition, the separation process can be performed by laser, scribe, or the like. It is also possible to separate the liquid crystal panel 10 by scanning a laser or scribe along the groove 46. At this time, even if chipping or the like occurs, the main surface of the liquid crystal panel 10 is protected by the filler 44, so that the separation process can be performed stably. Further, it is preferable to remove minute scratches on the sectional surface by performing an etching process after the separation.

  The filler 44 is removed after the separation process. The filler 44 can be peeled off by being immersed in hot water of 70 ° C. or higher, ether, high-temperature alcohol, or the like. Since almost no stress is applied to the liquid crystal panel 10 at the time of peeling, there is little risk of breakage or the like. In addition, since a minute scratch is removed by etching in the cross section after etching, it is possible to suppress a decrease in strength. The liquid crystal panel 10 from which the filler 44 has been removed is appropriately processed in a subsequent process.

  In the present embodiment, the groove portion 46 is formed in the filler 44 in the groove forming step as a preceding stage of the separation step, but the groove forming step can be omitted. In that case, the liquid crystal panel 10 is divided together with the filler 44 using a scribing device or a laser device. It is possible to prevent the filler 44 from absorbing an impact at the time of dividing, and to prevent the glass pieces scattered at the time of dividing from damaging the main surface of the liquid crystal panel 10. Further, the filler 44 is also configured as a protective material for the liquid crystal panel 10 when removing minute scratches on the end face by etching after dividing.

  Further, in the present embodiment, the thinning and dividing process of the liquid crystal panel has been described, but the present invention can also be applied to the manufacture of an organic EL display, a cover glass, and the like using a glass substrate.

  The above description of the embodiment is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

10-liquid crystal panel 12-first glass substrate 14-second glass substrate 16-functional layer 18-liquid crystal sealing material 20-periphery sealing material 30-protective film 32-end face sealing material 40-conveying roller 42-spray nozzle 44-Filler 46-Groove

Claims (3)

A method of manufacturing a thin glass substrate applicable to a flat panel display,
Masking all or part of the non-use area of the glass substrate having a use area located in the center and a non-use area around the use area;
Thinning the used area by etching the glass substrate with the non-used area masked;
Filling the etched area of use with a filler;
Separating the non-use area from the use area with the filler filled in the use area;
A method for producing a thin glass substrate containing at least   The method for manufacturing a thin glass substrate according to claim 1, wherein the filler is filled up to the same height as the non-use area. The filler further comprises etching resistance, and further includes a step of forming a groove so as to penetrate the filler through a peripheral edge of the filler;
The method for producing a thin glass substrate according to claim 1, wherein the non-use area is separated from the use area by etching.

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