JP7251704B2 - Etching liquid for glass and method for manufacturing glass substrate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a glass etchant for cutting and perforating glass, and a glass substrate manufacturing method using the same.

Various techniques exist for cutting and perforating glass. Conventionally, methods such as scribe break, laser ablation processing, ultrasonic spindle, and wet etching processing were often used.

Among these methods, when the scribe break is adopted, it is difficult to form a glass panel having a rounded contour. In addition, laser ablation processing tends to cause problems such as slow processing speed and contamination caused by ablation debris. With an ultrasonic spindle, there is a risk that the strength will decrease due to scratches after processing, and it has been difficult to keep the processing end face perpendicular to the main surface in wet etching processing.

Therefore, some conventional techniques use both laser technology and etching technology so as to modify the parts of the glass to be cut or perforated with a laser, and then wet-etch the modified parts. (see, for example, Patent Document 1). With such a technique, it was said that the rate of etching of the altered parts of the glass is about 3 to 5 times faster than that of the other parts, so that the glass can be suitably cut or perforated.

JP 2011-124752 A

However, even in the above-described prior art, it was sometimes impossible to obtain cut surfaces and through-holes of desired shapes due to the nature (isotropy) of etching to progress equally in the vertical and horizontal directions. For example, in the cut surface, the central portion in the thickness direction often becomes convex. Also, in the through-hole, the inner diameter of the central portion in the thickness direction farther from both main surfaces is smaller than the opening diameter near the two main surfaces, and when viewed in cross section, the through-hole has a constricted portion in the central portion in the thickness direction. I often lost it.

An object of the present invention is to provide an etchant for glass and a method for manufacturing a glass substrate that can minimize the isotropic influence of wet etching.

The glass etchant according to the present invention is for etching glass (in particular, a portion modified by laser processing so that etching proceeds easily). This glass etchant contains at least an etching inhibitor that reduces the etching rate of glass and contains at least one of an alkali and a fluorine complexing agent.

Examples of etching inhibitors include alkalis such as ammonium hydroxide, sodium hydroxide and potassium hydroxide, and fluorine complexing agents such as titanium oxide, aluminum chloride, boric acid and silicon dioxide.

The presence of such an etching inhibitor prevents active species such as hydrofluoric acid that contribute to glass etching from being consumed in the vicinity of the main surface of the glass substrate. Furthermore, a compound (e.g., fluoro complex, etc.) of the active species and the etching inhibitor may release the active species after moving to a position away from the main surface of the glass substrate. It becomes easy for the active species to reach even a position away from the . Therefore, etching in the direction perpendicular to the main surface of the glass substrate (eg, thickness direction, depth direction) is facilitated, and etching in the direction parallel to the main surface (eg, width direction) is minimized. can be suppressed.

In the glass etchant described above, it is preferable that the etching inhibitor adheres to the modified portion of the glass that has been modified to facilitate etching, thereby generating a reaction product that inhibits the etching reaction.

It is presumed that the etchant containing the above-mentioned etching-inhibiting substance tends to adhere reaction-inhibiting products (fences) to the cut surface and the inner wall of the through-hole more easily than a general etchant consisting of hydrofluoric acid and strong acid. ing. Therefore, the reaction in the direction parallel to the main surface of the glass substrate (e.g., width direction) is suppressed, and only the etching in the direction perpendicular to the main surface of the glass substrate (e.g., thickness direction, depth direction) is likely to proceed. It is considered. In fact, in experiments conducted by the applicant, anisotropic etching that minimizes the isotropic influence of wet etching was realized.

Moreover, the glass substrate manufacturing method which concerns on this invention uses the above-mentioned etching liquid for glass. This glass substrate manufacturing method includes at least a modification step and a first etching step. In the modifying step, the intended etching position of the glass substrate is modified by irradiating the glass substrate with a laser beam so that a focal line having a relatively high energy density is formed in the thickness direction of the intended etching position of the glass substrate. In the first etching step, after the modifying step, the intended etching position is etched using a glass etchant.

Furthermore, it is preferable to further include a second etching step of etching the intended etching position with an etchant containing at least hydrofluoric acid after the first etching step, if necessary. The second etching step is performed using a normal etchant (eg, hydrofluoric acid + hydrochloric acid + remaining water) that does not contain the above etching inhibitor from the beginning. Since the etching rate of such an etching solution increases as the concentration of hydrofluoric acid increases, it is possible to reduce the etching time as required.

According to the present invention, it is possible to minimize the isotropic influence of wet etching.

It is a figure which shows schematic structure of the liquid crystal panel which concerns on one Embodiment of this invention. 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 process included in one Embodiment of a liquid crystal panel manufacturing method. It is a figure which shows the process included in one Embodiment of a liquid crystal panel manufacturing method. It is a figure which shows the process included in one Embodiment of a liquid crystal panel manufacturing method. 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 scribing and breaking of a multi-panel glass base material; FIG. 2 is a diagram showing an outline of a divided multi-panel glass base material. It is a figure which shows the characteristic of the structure of a liquid crystal panel. It is a figure explaining the modification step concerning perforation processing. It is a figure explaining the modification step and etching step which concern on perforation processing. It is a figure which shows the structural example of the apparatus used for the etching step regarding perforation processing. It is a figure explaining the modification step concerning perforation processing. FIG. 4 is a schematic diagram for explaining the effects of etching inhibitors; FIG. 4 is a schematic diagram for explaining the effects of etching inhibitors;

An embodiment of a method for manufacturing a liquid crystal panel according to the present invention will be described below with reference to the drawings. FIG. 1A shows 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 an intermediate layer such as a liquid crystal layer interposed therebetween. Since the configurations of the array substrate 12 and the color filter substrate 14 can employ configurations similar to known configurations, description thereof is omitted here.

The array substrate 12 has electrode terminal portions 122 extending from the region where the color filter substrate 14 is bonded. A plurality of electric circuits are connected to the electrode terminal portion 122, and the liquid crystal panel 10 and the electric circuits are accommodated in the housing, so that, for example, the smartphone 100 as shown in FIG. Configured.

Next, an example of a method for manufacturing the liquid crystal panel 10 will be described. As shown in FIGS. 2(A) and 2(B), the liquid crystal panel 10 is generally manufactured as a multi-panel glass base material 50 including a plurality of such panels. A single liquid crystal panel 10 is obtained by cutting the multi-panel glass base material 50 .

In this embodiment, for convenience, six liquid crystal panels 10 are arranged in a matrix of 3 rows and 2 columns, and a transparent thin film (a transparent conductive film such as an ITO film or an organic conductive film, or a transparent protective film, etc.) is formed on the surface. ) 17 will be described below. However, the number of liquid crystal panels 10 included in the multi-panel glass base material 50 is not limited to this, and can be increased or decreased as appropriate.

First, as shown in FIGS. 3(A) and 3(B), the multi-panel glass base material 50 has a modified line 20 along a planned shape cutting line corresponding to the shape (contour) of the liquid crystal panel 10. It is formed. The modified line 20 is a filament array in which a plurality of filament layers are formed by a light beam pulse (with a beam diameter of about 1 to 5 μm) emitted from a pulse laser such as a picosecond laser or a femtosecond laser. (See FIGS. 4A and 4B). The modification line 20 has, for example, a perforation shape having a plurality of through-holes or modification layers, as shown in FIGS. 4(A) and 4(B). 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 this shape, and may have other shapes.

If the array substrate 12, the color filter substrate 14, and the transparent thin film 17 are treated with one laser beam at the same time, the liquid crystal layer may be damaged. Therefore, in the present embodiment, by adopting laser processing as shown in FIGS. 3(C) and 3(D), it is possible to suppress the occurrence of such problems. That is, as shown in FIG. 3C, after adjusting the focus and the intensity so that the modified lines 20 are formed only on the array substrate 12 from the array substrate 12 side, the laser beam is irradiated to the vicinity of the liquid crystal layer. It is preferable to make it difficult for energy to be transmitted. In this state, if it is possible to divide the multi-panel glass base material 50 by applying a physical action or a thermal action, the laser processing ends here.

On the other hand, if it is difficult to divide the multi-panel glass base material 50 in this state, as shown in FIG. It is preferable to irradiate the laser after adjusting the focus and intensity so as to form the modified line 20 . By performing the process shown in FIG. 3D, although the number of laser processing steps increases, it is possible to easily divide the multi-panel glass base material 50 while suppressing the occurrence of defects in the liquid crystal layer. become.

It is preferable that the light beam from the pico laser is appropriately adjusted in the condensing area. For example, by adjusting the condensing region of the laser light so that it does not reach the intermediate layer, it is possible to prevent the terminal wiring from corroding due to excessive penetration of the etchant in the etching process.

After the reforming lines 20 are formed along the planned shape cutting lines in the multi-panel glass preform 50, the multi-panel glass preform 50 is formed as shown in FIGS. 5(A) and 5(B). , an etching-resistant film 16 having etching resistance is attached to both main surfaces. Here, polyethylene having a thickness of 50 to 75 μm is used as the etching resistant film 16 . However, the structure of the etching resistant film 16 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 etching resistant film 16 is completed, subsequently, as shown in FIG. 5C, the etching resistant film 16 is irradiated with a laser beam along the planned shape cutting line corresponding to the shape of the liquid crystal panel 10 to be taken out. done. This laser beam irradiation removes the etching-resistant film 16 along the intended shape cutting line. Then, an opening is formed in the etching-resistant film 16 along the planned shape cutting line, and as a result, the multi-panel glass base material 50 is reformed in the same manner as in the configuration shown in FIG. 3(C). The formation position of the line 20 is exposed to the outside.

After the above-described laser processing is completed, as shown in FIG. 6, the glass base material 50 for multi-panel processing is introduced into an etching apparatus 300 and subjected to a first etching step using an etching liquid containing hydrofluoric acid and an etching inhibitor. If necessary, a second etching step (optional treatment) is performed using a normal etchant containing hydrofluoric acid, hydrochloric acid, or the like. Usually, an etchant containing about 1 to 10% by weight of hydrofluoric acid and about 5 to 20% by weight of hydrochloric acid is used, and if necessary, a surfactant or the like is used in combination. The liquid further contains an etching inhibitor.

Examples of etching inhibitors include alkalis such as ammonium hydroxide, sodium hydroxide and potassium hydroxide, and fluorine complexing agents such as titanium oxide, aluminum chloride, boric acid and silicon dioxide. Etching inhibitors have the effect of reducing the etching rate of an etchant mainly composed of hydrofluoric acid and strong acid. Normally, there is a positive correlation between the hydrofluoric acid concentration or the fluorine concentration and the etching rate, and the etching rate increases as the hydrofluoric acid concentration or the fluorine concentration increases.

However, by adding an etching inhibiting substance in an amount of about 0.05 to 5.00 molar equivalents with respect to the substance amount of hydrofluoric acid, the etching rate can be reduced from 0.01 to 3.0 even if the concentration of hydrofluoric acid or fluorine is increased. The applicant speculates that the anisotropic etching can be suppressed to a low level of about 00 μm/min, and by forming such a state, anisotropic etching that minimizes the isotropic effect of wet etching is realized. there is

Examples of compounds of hydrofluoric acid and etching inhibitors that have successfully achieved anisotropic etching include fluorotitanic acid (H ₂ TiF ₆ ), ammonium fluoride (NH ₄ F), and tetrafluoroborate. acid ( _HBF4 ), hexafluorophosphoric acid ( _HPF6 ), hexafluorosilicic acid ₍ H2SiF6), _{hexafluoroaluminic} acid ( _H3AlF6 ), hexafluoroantimonic acid ( _{HSbF6 )} , arsenic hexafluoride acid (HAsF ₆ ), hexafluorozirconic acid (H ₂ ZrF ₆ ), tetrafluoroberylic acid (H ₂ BeF ₄ ), heptafluorotantalic acid (H ₂ TaF ₇ ) and salts thereof.

In the etching apparatus 300, the multi-panel glass base material 50 is transported 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. 7B, a configuration may be adopted in which the multi-panel glass base material 50 is transported while being in contact with the overflowing etching solution in an overflow type etching chamber 304. is also possible.

Further, as shown in FIG. 7(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 bath 306 containing an etchant. It is also possible to

In any case, it is important not to cut the multi-panel glass base material 50 during the etching process by piercing the shape cutting lines in the thickness direction. 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.

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 adopt a configuration in which the concentration of hydrofluoric acid in the etching liquid is lowered as the etching apparatus 300 progresses to the subsequent stage.

When the multi-panel glass base material 50 passes through the etching device 300, the reforming lines 20 are etched. The etchant permeates the modified lines 20 faster than other locations, and the glass is melted along the lines, making it easier to cut the color filter substrate along the modified lines 20 . In addition, even if scratches or the like have occurred during laser irradiation, the scratches are likely to disappear.

When the etching process is finished, the attached etching resistant film 16 is peeled off. Subsequently, as shown in FIGS. 8A to 8C, the multi-panel glass base material 50 is removed in order to remove the regions of the color filter substrate 14 facing the electrode terminal portions 122 of the array substrate 12 . A process for forming terminal cut grooves 30 is performed. In this embodiment, a scribing wheel (wheel cutter) 250 is used to form terminal cut grooves 30 inside regions of the color filter substrate 14 facing the electrode terminal portions 122 of the array substrate 12 . The terminal cutting grooves 30 are formed along the planned terminal cutting lines in order to remove the regions of the color filter substrate 14 facing the electrode terminal portions 122 of the array substrate 12 .

After the formation of the terminal section cut grooves 30 by the scribing wheel 250 is completed, the division of the multi-panel glass base material 50 and the removal of the regions facing the electrode terminal sections 122 are performed. Modified lines 20 are formed in the multi-panel glass preform 50 by laser filament processing, and by further etching the reformed lines, the multi-panel glass preform 50 is reformed with only a slight mechanical pressure. A split can be made at the quality line 20 . For example, by applying a minute pressing force or a tensile force to the multi-panel glass base material 50 or by applying a minute ultrasonic vibration, the multi-panel glass base material 50 is soiled as shown in FIG. It is possible to divide without

Since the end faces of the separated liquid crystal panel 10 do not dare to be completely cut by the etching process, it is possible to prevent the occurrence of such a problem that the separated end faces of the liquid crystal panel 10 collide with each other during the etching process and are damaged. Further, it becomes possible to transport the multi-panel glass base material 50 as it is (in a large-sized state) in an incompletely cut state after the etching process. Furthermore, since the etchant does not reach the electrode terminals, it is not necessary to protect the electrode terminals with a masking agent having etching resistance. In addition, since the edge faces of the liquid crystal panel 10 are etched at least except for the central portion, the strength (for example, bending strength) of the liquid crystal panel is higher than when cutting is performed only by laser processing.

10(A) to 10(C) show a schematic configuration of the liquid crystal panel 10 after division. As shown in the figure, the end surfaces of the liquid crystal panel 10 are substantially perpendicular to the main surface. That is, it is possible to suppress the taper width (L1 to L4 in FIG. 10C) generated on each end surface of the thick array substrate 12 and the color filter substrate 14 to almost zero (specifically, 30 μm or less). be.

In this way, since the influence of side etching hardly occurs in manufacturing the liquid crystal panel 10, it is possible to design the multi-panel glass preform 50 in which the liquid crystal panels 10 are arranged close to each other. On the other hand, the proportion of the treatment with an etchant containing an etching inhibitor (first etching step) is reduced, and the proportion of the treatment with an etchant containing hydrofluoric acid, hydrochloric acid, etc. (second etching step) is increased. , it is possible to increase the values of the taper widths L1 to L4. It is preferable to appropriately adjust the ratio of the treatment with the etchant containing the etching inhibitor in consideration of the required shape of the end face, the required etching rate, and the like.

Next, another embodiment of punching processing will be described with reference to FIGS. 11 to 14. FIG. FIG. 11 shows one step in processing a glass substrate 510 to fabricate a glass interposer with multiple through holes. In this embodiment, the glass substrate 510 undergoes at least a modification step and an etching step in manufacturing the glass interposer.

The type of the glass substrate 510 is not particularly limited as long as it is glass, but non-alkali glass is preferable when used for packaging semiconductor elements like a glass interposer. This is because, in the case of alkali-containing glass, the alkali component in the glass may precipitate and adversely affect the semiconductor device. Further, the thickness of the glass substrate 510 is not particularly limited, and the glass substrate 10 can be suitably processed with a thickness of 0.1 mm to 2.0 mm, for example.

In the modifying step, laser light is irradiated from the laser head 512 to the formation planned positions of the plurality of through holes in the glass substrate 510 . The irradiated laser light passes through an optical system unit 514 for forming a focal line with relatively high energy density over the thickness direction of the glass substrate 510 .

The optical system unit 514 is composed of a single or a plurality of optical elements (such as lenses), and converts the laser light from the laser head 512 into a laser light having a length within a predetermined range in the thickness direction of the glass substrate 510. configured to focus to a focal line.

Therefore, by irradiating the glass substrate 510 with this laser beam, the through-hole formation planned positions in the glass substrate 510 are reformed over the entire thickness direction, and for example, void-shaped reformed portions 102 are formed. In order to form a plurality of modified portions 102 on the glass substrate 510, a stage that moves the glass substrate 510 on the XY plane may be used, or a laser processing apparatus having a laser head 512 and an optical system unit 514 may be used. The apparatus may be provided with a driving mechanism for moving these members in the XY directions.

The type and irradiation conditions of the laser light are not limited as long as the position where the through-hole is to be formed in the glass substrate 510 can be modified so as to be easily etched. In this embodiment, the laser head 512 irradiates laser light oscillated from a short pulse laser (eg, picosecond laser, femtosecond laser), but, for example, CO ₂ laser, UV laser, etc. may be used. . In this embodiment, the output is controlled so that the average laser energy of the laser light is about 30 μJ to 300 μJ.

After the modifying step, by etching the modified portion formed at the through hole formation planned position in the glass substrate 510, the modified portion 102 is dissolved, and the through hole is formed at the through hole formation planned position.

The modification step and subsequent etching step will be described with reference to FIGS. 12(A) to 12(C). FIG. 12(A) shows the modification step described above. The laser light emitted from the laser head 512 is condensed by the optical system unit 514 at the position where the through hole is to be formed in the glass substrate 510, and a focal line is formed in the thickness direction of the through hole position. The optical system unit 514 includes, for example, at least a diffusion lens for diffusing the laser light and a condenser lens for condensing the laser light. can do.

As a result, as shown in FIG. 12B, the modified portion 102 is formed over the entire thickness direction of the glass substrate 10 at the position where the through hole is to be formed. The modified portion 102 exhibits the property of being more easily etched than other portions by receiving energy from the laser beam. By bringing an etchant into contact with the modified portion 102, the modified portion 102 is dissolved, and as a result, a through hole 104 is formed at the position where the through hole is to be formed as shown in FIG. 12(C). Become.

In the etching step, as shown in FIG. 13A, the glass substrate 510 is introduced into an etching apparatus 520 and etched with an etching solution containing hydrofluoric acid, hydrochloric acid, and the like. In the etching apparatus 520 , the glass substrate 510 is etched by bringing an etchant into contact with one or both surfaces of the glass substrate 510 in the etching chamber 522 while the glass substrate 510 is transported by transport rollers.

Here, as shown in FIG. 13B, spray etching is performed in each etching chamber 522 of the etching apparatus 520 by spraying an etchant onto the glass substrate 510 . As the etchant, for example, an etchant containing 1 to 10% by weight of hydrofluoric acid, 5 to 20% by weight of hydrochloric acid, and the above-described etching inhibitor is used. Since a cleaning chamber for washing away the etchant adhering to the glass substrate 510 is provided in the subsequent stage of the etching chamber 522 in the etching device 520, the glass substrate 510 is removed from the etching device 520 with the etchant removed. discharged from

In addition to the technique of spraying the etchant, it is also possible to bring the etchant into contact with the glass substrate 10 by immersing the glass substrate 510 in the etchant. However, from the viewpoint of allowing the etchant to permeate the narrow through-holes, it is preferable to employ a method of spraying the etchant as shown in FIGS. 13(A) and 13(B).

By spraying the etchant onto the glass substrate 510 with a sufficient pressure, the modified portion 102 of the glass substrate 510 is normally appropriately dissolved to form the through hole 104 in the glass substrate 510 as shown in FIG. 12(C). is formed. In this embodiment, the discharge pressure during spraying is, for example, 0.05 Mpa to 0.10 Mpa, and the amount of etchant sprayed from each spray nozzle is about 1.25 to 2.50 liters/minute. Favorable results were obtained.

In processing using a conventional etchant, depending on the spray pressure, concentration, and viscosity of the etchant, or the size of the modified portion 102, as shown in FIG. Sometimes it was formed. Such a through-hole 105 is not very preferable because it may cause problems such as poor conduction when used as an interposer.

In this embodiment, by appropriately using an etchant containing an etching inhibitor, a narrowed portion is less likely to be formed in the central portion in the thickness direction of the glass substrate 510, as shown in FIG. 14(B).
In this way, by using an etchant containing an etching inhibitor, side etching caused by the isotropy of wet etching hardly occurs, so that a through hole without a constricted portion can be formed. On the other hand, by decreasing the proportion of the treatment with the etchant containing the etching inhibitor (first etching step) and increasing the proportion of the treatment with the normal etchant (second etching step), It is possible to adjust the shape. The ratio between the first etching step and the second etching step may be appropriately adjusted in consideration of the required shape of the through hole, the required etching rate, and the like. As mentioned above, the second etching step is an optional process, so the ratio can be zero.

Microcracks in the through-holes formed by employing the above-described method are reduced in size or eliminated by spray etching. Therefore, there is an advantage that not only can the shape of the through-hole be preferably maintained, but also the strength of the glass interposer can be maintained. Also, although an example in which the glass substrate 510 is used as a glass interposer has been described here, the application of the glass substrate 510 is not limited to this. For example, it can be applied to MEMS packaging, microchip devices for life science, and the like.

Here, the mechanism of anisotropic etching in the above embodiment will be described with reference to FIG. 15 . As shown in the figure, in a chemical equilibrium state, the fluoro complex (here, fluorotitanic acid) becomes an active species at a position away from the main surface of the glass substrate as the hydrofluoric acid is consumed by the etching process. It is easy to release hydrofluoric acid. As a result, the hydrofluoric acid can easily reach a position distant from the main surface of the glass substrate. Therefore, etching in a direction perpendicular to the main surface of the glass substrate (eg, thickness direction, depth direction) easily progresses.

When hydrofluoric acid is continuously consumed in the vicinity of the main surface of the glass substrate, etching progresses in the direction parallel to the main surface of the glass (eg, width direction), and the influence of isotropic etching tends to occur. We speculate that the action of the etch inhibitor may allow the effects of isotropic etching to be minimized.

Subsequently, the effect of the etching liquid for glass containing the etching inhibitor according to the embodiment of the present invention will be described by actually using examples. First, with reference to FIGS. 16(A) to 16(D), an experimental method for verifying the effect of the etching solution for glass will be described. As shown in FIG. 16(A), prior to the etching process, first, the average laser energy of the laser light was controlled to be about 250 μJ, and then the glass substrate was reformed to a thickness of about 200 μm. A hole was formed.

Subsequently, an etching treatment was performed for about 40 minutes using an etchant (40° C.) having the composition shown in Table 1 below. FIG. 16B shows a glass substrate after etching with an etching solution according to a comparative example, and FIG. 16C shows a glass substrate after etching with an etching solution according to each example. is shown.

The etchant according to Comparative Example 1 is an etchant containing a hydrofluoric acid concentration of 0.90 mol/L adjusted so that the etching rate is about 1.0 μm.

On the other hand, Examples 1 to 6 are etching solutions in which ammonium hydroxide, potassium hydroxide, sodium hydroxide, silicon dioxide, boric acid, and aluminum chloride are added as etching inhibitors to hydrofluoric acid. . Since addition of these etching inhibitors reduces the etching rate, the concentration of hydrofluoric acid is higher than that of the etching liquid according to Comparative Example 1 so that the etching rate is about 1.0 μm/min.

After the etching process, as shown in FIG. 16(D), the width of the formed hole (W0 in the case of the comparative example, W1 in the case of the example) and the depth D of the hole were measured, and the depth value The value obtained by dividing D by the width value (W0 or W1) was defined as the "anisotropic frequency". It can be said that the larger the value of this anisotropic frequency, the more anisotropic etching has been achieved. In addition, the measurement of the glass substrate after etching was performed using an optical microscope.

As shown in Table 1, the anisotropic degree obtained with the etching liquid according to Comparative Example 1 was 3.1. Normally, in the case of isotropic etching, the anisotropy degree is 1, but here, since modified holes are formed by laser processing, the anisotropic degree greatly exceeds 1 even without adding an etching inhibitor. degrees are obtained.

Furthermore, the anisotropy degrees obtained with the etching solutions according to Examples 1 to 6, each containing an etching inhibitor, are all higher than the anisotropy degrees obtained with the etching solution according to Comparative Example 1. value is obtained. From this, it can be seen that anisotropic etching is further realized by the etching inhibitor.

Here, Table 2 is used to explain another experimental result.

The etchant according to Comparative Example 2 is an etchant adjusted to have a hydrofluoric acid concentration of 0.10 mol/L. The etching solutions according to Examples 7 to 12 contained 0.10 molar equivalents of etching inhibitors (ammonium hydroxide, potassium hydroxide, sodium hydroxide, silicon dioxide, boric acid, and aluminum chloride) with respect to the amount of hydrofluoric acid. ) is added.

As shown in Table 2, the anisotropic degree obtained with the etchant according to Comparative Example 2 was 3.0. On the other hand, the anisotropy degrees obtained with the etching solutions according to Examples 7 to 12, to which the etching inhibitors were respectively added, were all higher than the anisotropy degrees obtained with the etching solution according to Comparative Example 2. High values (up to 6.8) are obtained. From the experimental results shown in Table 2, it can be seen that the anisotropic etching is further realized by the etching inhibitor.

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-Etching resistant film 17-Transparent thin film 20-Modification line 30-Terminal cut groove 50-Multi-panel glass base material 100-Smartphone 122-Electrode terminal part 250—scribing wheel 300—etching device 302, 304—etching chamber 306—etching tank

Claims (3)

A glass etchant for anisotropically etching a modified portion of glass that has been modified so as to be easily etched by irradiation with a laser beam and that dissolves upon contact with the etchant . There is
hydrofluoric acid;
An etching inhibitor that reduces the etching rate of glass, and is either an alkali containing ammonium hydroxide, sodium hydroxide, or potassium hydroxide, or a fluorine complexing agent containing titanium oxide, aluminum chloride, boric acid, or silicon dioxide. an etching inhibitor containing at least one;
Etching liquid for glass containing at least . A method for manufacturing a glass substrate using the etching solution for glass according to claim 1,
A reforming step of modifying the intended etching position by irradiating the glass substrate with a laser beam so that a focal line having a relatively high energy density is formed in the thickness direction of the intended etching position of the glass substrate;
After the modifying step, a first etching step of etching the intended etching position using the glass etchant;
A glass substrate manufacturing method comprising at least 3. The method of manufacturing a glass substrate according to claim 2, further comprising a second etching step of etching the intended etching position with an etchant containing at least hydrofluoric acid after the first etching step.

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