TW201722881A - Method for producing glass with fine structure - Google Patents

Abstract

The invention provides a method for producing glass with a fine structure that suppresses formation of low-gradient pores and forms a fine structure of deep holes or grooves and the like having higher straightness in the direction of thickness of the substrate. The invention pertains to a method for producing glass with a fine structure having an etching step for etching by radiating ultrasonic waves onto the glass, the etching solution used in the etching step including hydrofluoric acid; one or more inorganic acids selected from the group comprising nitric acid, hydrochloric acid, and sulfuric acid; and a surfactant. In the etching solution, the hydrofluoric acid concentration is 0.05-8.0 mass%, the inorganic acid concentration is 2.0-16.0 mass%, and the surfactant content is 5-1000 ppm.

Description

Method for manufacturing glass with microstructure

The present invention relates to a method of manufacturing a glass having a microstructure such as a through hole, a bottomed hole, or a groove formed by a laser pulse. More specifically, a modified portion or a processed hole is formed by irradiating a glass substrate or the like with a laser beam, and the modified portion or the processed hole is subjected to ultrasonic irradiation etching to perform removal processing. A method of producing a glass having the above microstructure.

As a method of forming a desired hole or groove on a glass substrate by etching a glass substrate on which a modified portion or a minute processed hole is formed, for example, Patent Document 1 discloses a method of irradiating a glass with a laser. A metamorphic portion is formed by a pulse, and a hole or a groove is formed by etching an etching solution having an etching rate (hereinafter, also referred to as an etching rate) of the modified portion larger than an etching rate of the glass substrate. Further, Patent Document 2 discloses a method of deforming a portion of a substrate, irradiating the portion with a laser to form a minute processing hole, and then processing the substrate by etching. That is, as shown in FIG. 1, the desired hole is formed by etching the glass substrate 11 on which the altered portion or the minute processed hole is formed.

In particular, when a glass substrate or the like having a through hole is used for an electronic substrate for use in a plug-in type or the like, a step of forming a subsequent electrode or the like is considered, and further, in order to secure The predetermined current, for example, the through hole is preferably linear.

However, in the prior art such as Patent Documents 1, 2, etc., there is a case where the inclination of the hole formed by etching becomes small, and even a deep hole cannot be formed. In order to form a desired shape by expanding the fine metamorphic portion or the processed hole by etching, the etching rate of the glass base material is not zero. Moreover, since it is difficult for the etching liquid to enter and exit in the fine degraded portion or the processing hole, even if the rod, the plate or the propeller-like stirrer is rotated in the etching liquid bath, or the etching liquid is stirred by foaming, the etching is performed. The closer the portion closer to the surface of the substrate, the slower the portion closer to the inside of the substrate. When the etching rate in the metamorphic portion is larger than the portion other than the metamorphic portion, the entry or exit of the etching liquid or the like is not so important for the purpose of forming a hole having a large inclination and a high linearity. However, when the glass having the characteristic that the difference between the etching rate of the portion other than the modified portion and the modified portion is small is small, the modified portion is etched to the inside of the substrate, and is deteriorated around the modified portion near the surface of the substrate. The etching of the portion other than the portion is accelerated, and there is a problem that as shown in FIG. 2, the smaller the difference in the etching rate, the smaller the inclination of the hole near the surface of the substrate.

Patent Document 1: Japanese Laid-Open Patent Publication No. 2011-37707

Patent Document 2: Japanese Laid-Open Patent Publication No. 2001-105398

The present invention has been made in view of the above problems, and an object thereof is to provide a method for producing a microstructured glass using a laser pulse as follows, which suppresses the microstructure A method of manufacturing a glass having a low inclination and forming a microstructure having a higher linearity and a deeper hole or groove in the thickness direction of the glass substrate. In particular, the present invention provides a method for manufacturing a microstructured glass using a laser pulse, which suppresses the formation of a low-inclined hole of the microstructure and forms a linear line in the thickness direction of the substrate. The pores serve as a method of manufacturing the microstructured glass. Further, it is an object of the present invention to provide a method for producing a glass having a microstructure which is industrially advantageous and which uses a laser pulse.

The invention provides a method for manufacturing a microstructured glass, which has an etching step of irradiating a glass with ultrasonic waves and etching, wherein the etching liquid used in the etching step contains hydrofluoric acid and is selected from the group consisting of nitric acid, hydrochloric acid and sulfuric acid. One or more inorganic acids and a surfactant in the group, the hydrofluoric acid concentration in the etching solution is 0.05% by mass to 8.0% by mass, and the inorganic acid concentration is 2.0% by mass to 16.0% by mass, and the surfactant is The content is 5 ppm to 1000 ppm.

By using the method for producing a microstructured glass of the present invention, it is possible to manufacture a glass which suppresses the formation of a hole having a low inclination and forms a microstructure having a higher linearity and a deeper hole or groove in the thickness direction of the substrate. In particular, there is provided a method for manufacturing a microstructured glass using a laser pulse as follows, which suppresses formation of a low-tilt hole provided in the microstructure, and forms a through-hole having a higher linearity in a thickness direction of the substrate. As a method of manufacturing a microstructured glass. Moreover, it is an object of the present invention to provide an industrially advantageous combined laser pulse with a microstructure The manufacturing method of glass.

11‧‧‧ glass substrate

12‧‧‧Deformation or processing hole

13‧‧‧Open end generated at the beginning of etching

14‧‧‧through holes

21‧‧‧Laser pulse

51a, 51b‧‧‧An angle formed by the surface of the substrate and the side of the hole

Fig. 1 is a schematic cross-sectional view showing a method of etching a glass substrate of the prior art.

2 is a schematic cross-sectional view showing a method of etching a glass substrate in the prior art, in particular, a case where a difference between etching rates of a modified portion and a glass substrate is small.

Fig. 3 is a schematic cross-sectional view showing a step of forming a modified portion in the first embodiment.

Fig. 4 is a schematic cross-sectional view showing the glass substrate of the first embodiment of the method for measuring the hole after etching.

Fig. 5 is an image of a cross-sectional observation result after etching of the glass substrate of Example 1.

Fig. 6 is an image of a cross-sectional observation result after etching of the glass substrate of Comparative Example 1.

Fig. 7 is an image of a cross-sectional observation result after etching of the glass substrate of Example 12.

Fig. 8 is an observation result image after the formation of the modified portion or the processed hole of the glass substrate of Example 14 and before etching.

Fig. 9 is an image of a cross-sectional observation result after etching of the glass substrate of Example 14.

The method for producing a microstructured glass of the present invention is characterized in that it has an etching step of irradiating a glass with ultrasonic waves and etching, and the etching liquid used in the etching step contains hydrofluoric acid selected from the group consisting of nitric acid, hydrochloric acid and sulfuric acid. One or more inorganic acids and a surfactant in the composition group, and the hydrofluoric acid concentration in the etching solution is 0.05% by mass to 8.0% by mass, The organic acid concentration is 2.0% by mass to 16.0% by mass, and the content of the surfactant (mass concentration) is 5 ppm to 1000 ppm.

Preferably, the method for producing a microstructured glass of the present invention comprises the step of irradiating a laser with a laser pulse to form a modified portion or a processed hole before the etching step. That is, it is preferred that the glass used in the etching step form a metamorphic portion or a processed hole before the etching step.

Before the details of the etching process, the step of forming the modified portion or the processed hole in the glass (hereinafter also referred to as "the modified portion forming step") will be described.

As a step (method) for forming a modified portion which is predetermined to be removed by subsequent etching in order to form a microstructure such as a through hole in the glass, the method described in JP-A-2008-156200 can be used. That is, the laser beam of the wavelength λ is condensed by the lens and irradiated with the glass, and the portion irradiated with the laser pulse in the glass forms a modified portion or a processed hole.

In the glass which can be used in the present invention (hereinafter also referred to as glass for laser processing), quartz glass, borosilicate glass, aluminosilicate glass, soda lime glass, or titanium-containing tellurite glass is suitable as a mine. Shot processing glass. Further, an alkali-free glass which does not substantially contain an alkaline component (alkali metal oxide) or a low-alkali glass which contains only a trace amount of an alkaline component is suitable as a glass for laser processing.

Further, in order to effectively increase the absorption coefficient, the glass may contain at least one of oxides of metals selected from the group consisting of Bi, W, Mo, Ce, Co, Fe, Mn, Cr, V, and Cu as a coloring component.

As the borosilicate glass, Corning's #7059 glass (the composition is expressed by mass%, 49% of SiO ₂ , 10% of Al ₂ O ₃ , 15% of B ₂ O ₃ , 25% of RO (alkaline earth) Metal oxide)) or Pyrex (registered trademark) (glass code 7740) and the like.

Embodiment 1 of the aluminosilicate glass may have the composition described below.

It is composed of 50% to 70% SiO ₂ , 14 to 28% Al ₂ O ₃ , 1 to 5% Na ₂ O, 1 to 13% MgO, and 0 to 14% ZnO glass. Things.

Another embodiment 2 of the aluminosilicate glass may have the composition described below.

It is represented by mass %, containing 56-70% SiO ₂ , 7-17% Al ₂ O ₃ , 0-9% B ₂ O ₃ , 4-8% Li ₂ O, 1-11% MgO, 4~12% ZnO, 0~2% TiO ₂ , 14-23% Li ₂ O+MgO+ZnO, 0~3% CaO+BaO glass composition.

As another embodiment 3 of the aluminosilicate glass, there may be a group as described below to make.

It is represented by mass %, containing 58 to 66% of SiO ₂ , 13 to 19% of Al ₂ O ₃ , 3 to 4.5% of Li ₂ O, 6 to 13% of Na ₂ O, and 0 to 5% of K ₂ O. 10 to 18% of R ₂ O (where R ₂ O=Li ₂ O+Na ₂ O+K ₂ O), 0 to 3.5% of MgO, 1 to 7% of CaO, 0 to 2% of SrO, 0~2% BaO, 2~10% RO (where RO=MgO+CaO+SrO+BaO), 0~2% TiO ₂ , 0~2% CeO ₂ , 0~2% Fe ₂ A glass composition of O ₃ , 0 to 1% of MnO (wherein TiO ₂ +CeO ₂ +Fe ₂ O ₃ +MnO=0.01 to 3%), and 0.05 to 0.5% of SO ₃ .

Another embodiment 4 of the aluminosilicate glass may have the composition described below.

It is represented by mass%, containing 60 to 70% of SiO ₂ , 5 to 20% of Al ₂ O ₃ , 5 to 25% of Li ₂ O+Na ₂ O+K ₂ O, and 0 to 1% of Li ₂ O. 3~18% Na ₂ O, 0~9% K ₂ O, 5-20% MgO+CaO+SrO+BaO, 0~10% MgO, 1~15% CaO, 0~4.5% A glass composition of SrO, 0 to 1% BaO, 0 to 1% TiO ₂ , and 0 to 1% ZrO ₂ .

Another embodiment 5 of the aluminosilicate glass may have the composition described below.

It is represented by mass %, containing 59 to 68% of SiO ₂ , 9.5 to 15% of Al ₂ O ₃ , 0 to 1% of Li ₂ O, 3 to 18% of Na ₂ O, and 0 to 3.5% of K ₂ O. 0 to 15% of MgO, 1 to 15% of CaO, 0 to 4.5% of SrO, 0 to 1% of BaO, 0 to 2% of TiO ₂ , and 1 to 10% of ZrO ₂ glass composition.

Soda lime glass is a glass composition widely used for, for example, sheet glass.

Embodiment 1 of the titanium-containing tellurite glass may have the composition described below.

It is represented by mol%, containing 5~25% of TiO ₂ , and SiO ₂ +B ₂ O ₃ is 50-79%, Al ₂ O ₃ +TiO ₂ is 5~25%, Li ₂ O+Na ₂ O+ K ₂ O+Rb ₂ O+Cs ₂ O+MgO+CaO+SrO+BaO is a glass composition of 5 to 20%.

Further, in the first embodiment of the titanium-containing tellurite glass, it is represented by mol%, and preferably contains 60 to 65% of SiO ₂ , 12.5 to 15% of TiO ₂ , and 12.5 to 15% of Na _{2 .} O, and SiO ₂ + B ₂ O ₃ is 70 to 75%.

Further, in the first embodiment of the titanium-containing niobate glass, it is more preferable to satisfy the following formula (Al ₂ O ₃ + TiO ₂ ) / (Li ₂ O + Na ₂ O + K ₂ O + Rb ₂ O +Cs ₂ O+MgO+CaO+SrO+BaO)≦0.9

(wherein the amount of each component is expressed in mol%).

Further, as another embodiment 2 of the titanium-containing tellurite glass, the composition described below may be provided. It is represented by mole %, containing 10 to 50% of B ₂ O ₃ , 25 to 40% of TiO ₂ , and SiO ₂ + B ₂ O ₃ is 20 to 50%, Li ₂ O+Na ₂ O+K ₂ O +Rb ₂ O+Cs ₂ O+MgO+CaO+SrO+BaO is a glass composition of 10 to 40%.

Embodiment 1 of the low alkali glass may have the composition described below.

In terms of mole %, it contains 45 to 68% of SiO ₂ , 2 to 20% of B ₂ O ₃ , 3 to 20% of Al ₂ O ₃ , 0.1 to 5.0% of TiO ₂ (excluding 5.0%), 0 to 9% of ZnO, and Li ₂ O+Na ₂ O+K ₂ O is a glass composition of 0 to 2.0% (excluding 2.0%).

Further, in the first embodiment of the low alkali glass, the coloring component is represented by mol%, and preferably contains 0 to 3.0% of CeO ₂ and 0 to 1.0% of Fe ₂ O ₃ . Further, in the first embodiment of the low alkali glass, an alkali-free glass which does not substantially contain an alkali metal oxide (Li ₂ O+Na ₂ O+K ₂ O) is more preferable.

The low alkali glass or alkali-free glass of the first embodiment described above contains TiO ₂ as an essential component. The content of TiO ₂ in the above-mentioned low-alkali glass or alkali-free glass is 0.1 mol% or more and less than 5.0 mol%, and the smoothness of the inner wall surface of the pore obtained by laser irradiation is superior. Preferably, it is 0.2 to 4.0 mol%, more preferably 0.5 to 3.5 mol%, and further preferably 1.0 to 3.5 mol%. By appropriately containing TiO ₂ with a low alkali glass or an alkali-free glass having a specific composition, even if it is irradiated with energy such as a weak laser, a metamorphic portion can be formed, and the metamorphic portion can be produced by a subsequent step. Ultrasonic irradiation etches and removes easily. Further, it is known that the bonding of TiO ₂ is substantially the same as the energy of ultraviolet light, and absorbs ultraviolet light. By generally containing TiO ₂ , as is generally known as charge transfer absorption, coloration can also be controlled by interaction with other colorants. Therefore, by adjusting the content of TiO ₂ , the absorption of specific light can be made moderate. By making the glass have an appropriate absorption coefficient, it is easy to form a modified portion to form a hole by etching. Therefore, it is preferable to contain TiO ₂ appropriately from these viewpoints.

Further, the low alkali glass or the alkali-free glass of the first embodiment described above may contain ZnO as an optional component. The content of ZnO in the above low alkali glass or alkali-free glass is preferably 0 to 9.0 mol%, more preferably 1.0 to 8.0 mol%, further preferably 1.5 to 5.0 mol%, and particularly preferably 1.5 to 3.5. Moer%. In the same manner as the TiO ₂ , ZnO exhibits an absorption component in the region of ultraviolet light. Therefore, ZnO is a component which acts effectively on the glass of the present invention as long as it is contained.

The low alkali glass or the alkali-free glass of the first embodiment described above may contain CeO ₂ as a coloring component. In particular, by using in combination with TiO ₂ , the metamorphic portion can be formed more easily. The content of CeO ₂ in the above low alkali glass or alkali-free glass is preferably 0 to 3.0 mol%, more preferably 0.05 to 2.5 mol%, further preferably 0.1 to 2.0 mol%, and particularly preferably 0.2~ 0.9 mol%.

Fe ₂ O _{3 is} also effective as a coloring component in the glass used in the present invention, and may also contain Fe ₂ O ₃ . In particular, by using TiO _{2 in} combination with Fe ₂ O ₃ or by using TiO ₂ , CeO ₂ and Fe ₂ O ₃ together, it becomes easy to form a deteriorated portion. The content of Fe ₂ O ₃ in the above low alkali glass or alkali-free glass is preferably 0 to 1.0 mol%, more preferably 0.008 to 0.7 mol%, still more preferably 0.01 to 0.4 mol%, and particularly preferably 0.02~0.3 mol%.

The low alkali glass or the alkali-free glass according to the first embodiment is not limited to the above-exemplified components, and the absorption coefficient of the specific wavelength (wavelength of 535 nm or less) of the glass may be 1 to 50 by containing an appropriate coloring component. /cm, preferably 3 to 40/cm.

Further, in another embodiment 2 of the low alkali glass, the composition described below may be provided.

In terms of mole %, SiO ₂ is 45-70%, B ₂ O ₃ is 2-20%, Al ₂ O ₃ is 3-20%, CuO is 0.1-2.0%, TiO ₂ is 0-15.0%, ZnO 0~9.0%

Li ₂ O+Na ₂ O+K ₂ O is a glass composition of 0 to 2.0% (excluding 2.0%).

Further, in the second embodiment of the low alkali glass, an alkali-free glass which does not substantially contain an alkali metal oxide (Li ₂ O+Na ₂ O+K ₂ O) is more preferable.

The low alkali glass or alkali-free glass of the above-described second embodiment may contain TiO _{2 in the} same manner as the low alkali glass or the alkali-free glass of the first embodiment. In the low alkali glass or the alkali-free glass of the _second embodiment, the content of TiO ₂ is 0 to 15.0 mol%, and it is preferable that the smoothness of the inner wall surface of the pore obtained by laser irradiation is excellent. 0 to 10.0 mol%, more preferably 1 to 10.0 mol%, further preferably 1.0 to 9.0 mol%, and particularly preferably 1.0 to 5.0 mol%.

Further, the low alkali glass or the alkali-free glass of the second embodiment may contain ZnO. The content of ZnO in the low alkali glass or alkali-free glass of the second embodiment is 0 to 9.0 mol%, preferably 1.0 to 9.0 mol%, more preferably 1.0 to 7.0 mol%. In the same manner as the TiO ₂ , ZnO exhibits an absorption component in the region of ultraviolet light. Therefore, ZnO is a component which acts effectively on the glass of the present invention as long as it is contained.

Further, the low alkali glass or the alkali-free glass of the second embodiment contains CuO. The content of CuO in the above low alkali glass or alkali-free glass is preferably 0.1 to 2.0 mol%, more preferably 0.15 to 1.9 mol%, further preferably 0.18 to 1.8 mol%, and particularly preferably 0.2 to 1.6. Moer%. By containing CuO, the glass is colored, and by setting the absorption coefficient of the wavelength of the specific laser to an appropriate range, the energy of the irradiation laser can be appropriately absorbed, and the deteriorated portion which is the basis of the pore formation can be easily formed.

The low alkali glass or the alkali-free glass according to the second embodiment is not limited to the above-exemplified components, and the absorption coefficient of the specific wavelength (wavelength of 535 nm or less) of the glass may be 1 to 50 by containing an appropriate coloring component. /cm, preferably 3 to 40/cm.

The low alkali glass or the alkali-free glass of the above-described first and second embodiments may contain MgO as an optional component. The MgO alkaline earth metal oxide has a feature of suppressing an increase in the thermal expansion coefficient and preventing the strain point from excessively decreasing, and also improves the meltability, and thus may contain MgO. The content of MgO in the low alkali glass or alkali-free glass is preferably 15.0 mol% or less, more preferably 12.0 mol% or less, further preferably 10.0 mol% or less, and particularly preferably 9.5 mol% or less. Further, the content of MgO is preferably 2.0 mol% or more, more preferably 3.0 mol% or more, further preferably 4.0 mol% or more, and particularly preferably 4.5 mol% or more.

The low alkali glass or the alkali-free glass of the above-described first and second embodiments may contain CaO as an optional component. Similarly to MgO, CaO has a feature of suppressing an increase in the coefficient of thermal expansion and preventing the strain point from being excessively lowered, and also improves the meltability, and therefore may contain CaO. The content of CaO in the low alkali glass or alkali-free glass is preferably 15.0 mol% or less, more preferably 12.0 mol% or less, further preferably 10.0 mol% or less, and particularly preferably 9.3 mol% or less. Further, the content of CaO is preferably 1.0 mol% or more, more preferably 2.0 mol% or more, further preferably 3.0 mol% or more, and particularly preferably 3.5 mol% or more.

The low alkali glass or the alkali-free glass of the above-described first and second embodiments may contain SrO as an optional component. In the same manner as MgO and CaO, SrO has a feature of suppressing an increase in the coefficient of thermal expansion and preventing the strain point from being excessively lowered, and also improves the meltability. Therefore, SrO may be contained in order to improve devitrification characteristics and acid resistance. The content of SrO in the low alkali glass or alkali-free glass is preferably 15.0 mol% or less, more preferably 12.0 mol% or less, further preferably 10.0 mol% or less, and particularly preferably 9.3 mol% or less. Further, the content of SrO is preferably 1.0 mol% or more, more preferably 2.0 mol% or more, further preferably 3.0 mol% or more, and particularly preferably 3.5 mol% or more.

The phrase "substantially free of" means that the content of the component in the glass is less than 0.1 mol%, preferably less than 0.05 mol%, more preferably 0.01 mol% or less. In the present specification, the upper limit and the lower limit of the numerical range (the content of each component, the value calculated from each component, and the physical properties) may be appropriately combined.

The coefficient of thermal expansion of the glass used in the present invention is preferably 100 × 10 ^-7 / ° C or less, more preferably 70 × 10 ^-7 / ° C or less, further preferably 60 × 10 ^-7 / ° C or less, particularly preferably 50 × 10 ^-7 / ° C or less. Further, the lower limit of the coefficient of thermal expansion is not particularly limited, and may be, for example, 10 × 10 ^-7 / ° C or more, or 20 × 10 ^-7 / ° C or more.

The coefficient of thermal expansion was measured by the following method. First, a cylindrical glass sample having a diameter of 5 mm and a height of 18 mm was produced. This was heated from 25 ° C to the drop point of the glass sample, and the elongation of the glass sample at each temperature was measured to calculate the coefficient of thermal expansion. Calculate the average of the thermal expansion coefficients in the range of 50 to 350 ° C to obtain the average thermal expansion coefficient. The average coefficient of thermal expansion can be measured using a thermomechanical analyzer (TMA). The actual coefficient of thermal expansion was measured using a thermomechanical analyzer TMA4000SA from NETZSCH Co., Ltd. at a temperature increase rate of 5 ° C/min.

The shape of the glass is not limited, and for example, a glass plate is used. Further, in the step of forming the metamorphic portion, it is not necessary to use a so-called photosensitive glass, and the range of the glass that can be processed is wide. That is, in the modified portion forming step of the present invention, the glass which does not substantially contain gold or silver can be processed.

In particular, when the glass having high rigidity is subjected to laser irradiation, cracking is less likely to occur on either the upper surface and the lower surface of the glass, and the processing can be suitably performed by the modified portion forming step of the present invention. For example, a glass having a Young's modulus of 80 GPa or more is preferable.

Further, the absorption coefficient α can be calculated by measuring the transmittance and reflectance of the glass substrate having a thickness t (cm). For a glass substrate having a thickness t (cm), a transmittance T at a specific wavelength (wavelength of 535 nm or less) is measured using a spectrophotometer (for example, an ultraviolet visible near-infrared spectrophotometer V-670 manufactured by JASCO Corporation). (%) and reflectance R (%) at an incident angle of 12 °. The absorption coefficient α was calculated from the obtained measured value using the following formula.

α=(1/t)* ln{(100-R)/T}

The absorption coefficient α of the glass used in the present invention is preferably from 1 to 50/cm, more preferably from 3 to 40/cm.

The glass listed above is commercially available and can be obtained by purchasing such glass. Moreover, even if it is not purchased, the desired glass can be produced by a known forming method (for example, an overflow method, a floating method, a slit stretching method, a calendering method, etc.), and After cutting, grinding, etc., it is processed to obtain a glass composition of a target shape.

In the metamorphic portion forming step, the altered portion can be formed by one pulse irradiation. That is, in this step, the deteriorated portion can be formed by irradiating the laser pulse so that the irradiation positions do not overlap. However, it is also possible to illuminate the laser pulse by illuminating the pulse.

In the metamorphic portion forming step, the laser pulse is usually collected by a lens in such a manner as to focus on the inside of the glass. For example, in the case where a through hole is formed in a glass plate, the laser pulse is usually collected by focusing on the vicinity of the center in the thickness direction of the glass plate. Further, in the case where only the upper surface side of the glass plate (the incident side of the laser pulse) is processed, the laser pulse is usually collected by focusing on the upper surface side of the glass plate. On the contrary, in the case where only the lower surface side of the glass plate (the side opposite to the incident side of the laser pulse) is processed, the laser pulse is usually collected by focusing on the lower surface side of the glass plate. However, as long as the glass metamorphic portion can be formed, the laser pulse can also be focused on the outside of the glass. For example, the laser pulse can also be focused from a top or bottom surface of the glass sheet at a specific distance (eg, 1.0 mm) from the glass. In other words, as long as the metamorphic portion can be formed in the glass, the laser pulse can also be focused from the upper surface of the glass to a position within 1.0 mm in the near direction (the direction opposite to the direction of travel of the laser pulse) (including on the glass) Surface), or focusing from the underside of the glass at the rear (laser pulse through the glass) In the direction of 1.0mm (including the position of the surface below the glass) or focused on the inside.

In the case of a nanosecond laser or its device, the pulse width of the laser pulse is preferably from 1 to 200 ns (nanoseconds), more preferably from 1 to 100 ns, and even more preferably from 5 to 50 ns. Further, when the pulse width becomes larger than 200 ns, the peak of the laser pulse is lowered, and the smooth processing cannot be performed. The laser light composed of energy of 5 to 100 μJ/pulse is irradiated to the laser processing glass. By increasing the energy of the laser pulse, the length of the metamorphic portion can be lengthened in proportion thereto. The beam quality M ₂ value of the laser pulse can be, for example, 2 or less. By using a laser pulse having an M ₂ value of 2 or less, it becomes easy to form minute pores or minute grooves. In addition, in the following description, unless otherwise indicated, the description relating to laser is about a nanosecond laser or its apparatus.

In the metamorphic portion forming step, the laser pulse may be a high harmonic of a Nd:YAG laser, a high harmonic of a Nd:YVO ₄ laser, or a high harmonic of a Nd:YLF laser. The high harmonics are, for example, the second high harmonic, the third high harmonic, or the fourth high harmonic. The wavelength of the second harmonic of the lasers is around 532-535 nm. The wavelength of the third harmonic is around 355 to 357 nm. The wavelength of the fourth high harmonic is near 266 to 268 nm. By using these lasers, the glass can be processed inexpensively.

As a device used for laser processing suitable for the metamorphic portion forming step, for example, a high repetition rate solid pulsed UV laser manufactured by Coherent Co., Ltd.: AVIA355-4500 can be cited. The device is a third high harmonic Nd:YVO ₄ laser that achieves a maximum laser power of around 6 W at a repetition rate of 25 kHz. The third harmonic has a wavelength of 350 to 360 nm.

The wavelength of the laser pulse is preferably 535 nm or less, and may be, for example, in the range of 350 to 360 nm. On the other hand, when the wavelength of the laser pulse becomes larger than 535 nm, the irradiation spot becomes large, and the fabrication of a minute structure becomes difficult, and the periphery of the irradiation spot is liable to be broken due to the influence of heat.

As a typical optical system, the beam of the oscillation is expanded by 2 to 4 times by using a beam expander (at this point of time, the spot diameter Φ of the processing part is 7.0 to 14.0 mm), and the center of the laser is cut by a variable aperture. After that, the optical axis was adjusted by a galvanometer mirror, and the focus position was adjusted by using an f θ lens of about 100 mm to condense on the glass.

The focal length L (mm) of the lens is, for example, in the range of 50 to 500 mm, and may be selected from the range of 100 to 200 mm.

Further, the beam diameter D (mm) of the laser pulse is, for example, in the range of 1 to 40 mm, and may be selected from the range of 3 to 20 mm. Here, the beam diameter D is the beam diameter of the laser pulse when incident on the lens, and means the diameter in the range of [1/e ² ] times the intensity with respect to the intensity of the center of the beam.

In the step of forming the metamorphic portion, the value obtained by dividing the focal length L by the beam diameter D, that is, the value of [L/D] is 7 or more, preferably 7 or more and 40 or less, and may be 10 or more and 20 or less. This value is a value relating to the condensing property of the laser irradiated to the glass. The smaller the value, the more concentrated the laser is, and the more difficult it is to produce a uniform and long metamorphic portion. If the value is less than 7, there arises a problem that the laser power near the waist of the beam becomes too strong, and cracks are likely to occur inside the glass.

In the metamorphic portion forming step, it is not necessary to perform pre-treatment of the glass (for example, forming a film that promotes absorption of the laser pulse) before the laser pulse is irradiated. However, any such treatment may be carried out as long as the effects of the present invention are obtained.

The size of the aperture can also be changed to vary the diameter of the laser, thereby changing the numerical aperture (NA) to 0.020 to 0.075. If the NA becomes too large, the energy of the laser is concentrated only in the vicinity of the focus, and the metamorphic portion cannot be effectively formed in the thickness direction of the glass.

Further, by irradiating a pulsed laser having a small NA and irradiating with a single pulse to form a relatively long metamorphic portion in the thickness direction, it is effective for increasing the production time.

Preferably, the repetition frequency is set to 10 to 25 kHz, and the sample is irradiated with a laser. Further, the position (upper surface side or lower surface side) of the deteriorated portion formed on the glass can be adjusted to be optimum by changing the focus position in the thickness direction of the glass.

Further, by controlling the laser output from the control PC, the operation of the laser output and the mirror galvanometer can be controlled, and the laser can be irradiated to the glass substrate at a specific speed based on the two-dimensional drawing data created by using the CAD software or the like. on.

The portion that illuminates the laser forms a metamorphic portion that is different from the rest of the glass. The altered portion can be easily discriminated by an optical microscope or the like. Although there is a difference in each glass depending on the composition, the metamorphic portion is mostly formed in a cylindrical shape. The metamorphic portion reaches the vicinity of the lower surface from the vicinity of the upper surface of the glass.

It is considered that the metamorphic part is photochemically reacted by laser irradiation, and a defect such as E' center or non-crosslinked oxygen is generated, or a high temperature due to rapid heating or rapid cooling caused by laser irradiation is maintained. The area of the loose glass structure in the area.

In the opening technique in which the laser irradiation and the wet etching are used in the step of forming the deteriorated portion of the present invention, the altered portion can be formed by irradiation of one laser pulse.

The conditions selected in the step of forming the metamorphic portion include, for example, an absorption coefficient of glass of 1 to 50/cm, a laser pulse width of 1 to 100 ns, a laser pulse energy of 5 to 100 μJ/pulse, and a wavelength of 350 Å. At 360 nm, the beam diameter D of the laser pulse is 3 to 20 mm, and the focal length L of the lens is a combination of 100 to 200 mm.

Furthermore, it is also necessary to reduce the diameter of the metamorphic portion before etching. The glass plate is ground by the deviation. If the polishing is excessively performed, the effect of etching the modified portion is weakened, so the depth of the polishing is preferably from 1 to 20 μm from the upper surface of the glass plate.

The size of the metamorphic portion formed in the metamorphic portion forming step varies depending on the beam diameter D of the laser beam incident on the lens, the focal length L of the lens, the absorption coefficient of the glass, the power of the laser pulse, and the like. The obtained altered portion has a diameter of, for example, about 5 to 200 μm, and may be about 10 to 150 μm. Further, the depth of the metamorphic portion varies depending on the above-described laser irradiation conditions, the absorption coefficient of the glass, and the thickness of the glass, and may be, for example, about 50 to 300 μm.

Further, a plurality of holes may be formed in a continuous manner thereof, thereby forming grooves. In this case, a plurality of laser beams arranged in a line shape are used to form a plurality of modified portions arranged in a line shape. Thereafter, the groove is formed by etching the altered portion. The irradiation positions of the plurality of laser pulses may not overlap, as long as the holes formed by the etching combine the adjacent holes with each other.

Further, the method of forming the modified portion is not limited to the above. For example, a metamorphic portion or a machined hole may be formed by irradiation from the femtosecond laser device. In the case of a femtosecond laser or a device thereof, the conditions are not particularly limited as long as the effects of the present invention are obtained. For example, the pulse width of the laser pulse is preferably from 100 to 2000 fs (femtoseconds), more preferably from 200 to 1000 fs. Preferably, the repetition frequency is set to 0.5 to 10 kHz, and the sample is irradiated with a laser. The energy of the laser pulse is preferably 1 to 20 μJ/pulse. Further, it is preferable to adjust the optical system of the laser pulse of 1 to 20 μJ per pulse so as to form a point of the processing portion with a spot diameter of Φ 1 to 30 μm on the glass of the object. In the femtosecond laser or the device thereof, those obtained by appropriately combining the above conditions can be used.

Further, instead of the modified portion, a processing hole may be formed in advance in the glass substrate, and a final through hole or the like may be formed by an etching step in a subsequent step. The step of forming the machined hole is for example a suitable glass substrate (for example, for laser processing, reducing the processing threshold) A higher Ti-containing tellurite glass or the like is ablated or evaporated by irradiation with a laser having a specific characteristic, thereby forming a processed hole. As the laser device to be used, for example, a YAG laser having a center wavelength of 266 nm or 355 nm (pulse width of 5 to 8 nm), and a focal length L (mm) of the lens is, for example, in the range of 50 to 500 mm, preferably a repetition frequency is set. It is 10~25kHz, and the glass is irradiated with laser for 0.5~10 seconds.

It is possible to form a hole or a groove having a diameter of 10 to 100 μm or more by laser ablation, and thus, in combination with the etching process of the subsequent step, in addition to the enlargement of the aperture or the improvement of the linearity, The effect of making the deformed portion of the glass such as the debris around the processed portion inconspicuous or removing the fine crack.

The method of forming the metamorphic portion is not limited to the above method as long as the microstructure is formed on the glass substrate by the use of the etching step in the subsequent step.

The manufacturing method of the present invention has an etching step of irradiating the glass with ultrasonic waves. The pitting corrosion, vibration acceleration, and water flow generated by the ultrasonic wave promote the dispersion of the etching liquid and the product generated by the etching into the fine pores or grooves. By irradiating the ultrasonic waves during etching, the difference between the etching of the surface of the substrate of the fine holes or the grooves and the inside can be eliminated, and the holes and grooves having a large inclination and a large inclination (high linearity) and deep can be formed. .

If an ultrasonic wave is transmitted in a liquid, a phenomenon in which a void occurs in the liquid, that is, pitting corrosion occurs. Pitting corrosion is carried out by stretching and compressing water molecules while shaking and decompressing in a very short time, thereby promoting the flow of the etching liquid or the product generated by the etching to the fine holes or grooves. Internal. However, if the oscillation frequency is increased, the threshold value generated by the pitting will rise, and if it exceeds 100 kHz, it will rise sharply according to the exponential function, and it becomes difficult to cause pitting corrosion. The difference between the etching of the substrate surface and the inside of the fine hole or groove can be eliminated. The oscillating frequency of the ultrasonic illuminating etching is preferably in the range of 120 kHz or less, more preferably 10 to 120 kHz, so that the etchant is in the form of a finer, more inclined, deeper hole or groove. In terms of producing sufficient pitting corrosion, it is further preferably 20 to 100 kHz. Regarding the above oscillation frequency, two or more types of oscillation frequencies may be used in combination.

As the intensity of the ultrasound is not particularly limited, is preferably 0.10 ~ 5.0W / cm ^2, more preferably 0.15 ~ 4.0W / cm ^2, further preferably 0.20 ~ 3.0W / cm ^2. As long as the intensity of the ultrasonic waves in the above range is within the range of the glass to be processed, the intensity of the irradiated ultrasonic waves can be increased. The reason why the intensity of the ultrasonic waves in the above range is selected is that the effect of promoting the exchange of the etching liquid in the vicinity of the inside and the outside of the microstructure is increased, which is preferable. The intensity of the ultrasonic wave is obtained by dividing the output (in W) by the bottom area (in cm ² ) of the etching groove.

The ultrasonic treatment is not particularly limited, and a known device can be used. For example, W-113 (model, output 100W, oscillation frequency 28kHz/45kHz/100kHz, manufactured by Bento Electronics Co., Ltd., slot size: W240×D140×H100 (unit: mm)) or US-3R (model, output) 120W, oscillation frequency 40kHz, manufactured by AS ONE Co., Ltd., groove size: W303 × D152 × H150 (unit is mm) and so on.

In the etching step, in order to be able to perform etching only from one side, a surface protective film agent may be applied to the upper surface side or the lower surface side of the glass plate to protect it. A commercially available product can be used as the surface protective film agent, and examples thereof include SILITECT-II (manufactured by Trylaner International Co., Ltd.).

The etching liquid in the ultrasonic irradiation etching of the present invention contains hydrofluoric acid, one or more inorganic acids selected from the group consisting of nitric acid, hydrochloric acid, and sulfuric acid, and a surfactant. The etching liquid may contain other components as long as it does not impair the effects of the present invention. As such other ingredients, Examples thereof include inorganic acids other than hydrofluoric acid, nitric acid, hydrochloric acid, and sulfuric acid; organic acids such as oxalic acid, tartaric acid, iodoacetic acid, fumaric acid, and maleic acid; and chelating agents. The chelating agent is effective by preventing the metal ions from being misaligned and preventing reattachment to the surface of the substrate. Examples of the chelating agent include dimethylglyoxal oxime, dithizone, oxin, ethylenediaminetetraacetic acid, nitrotriacetic acid, hydroxyethylidene diphosphonic acid (HEDP), and nitrotrimethylenephosphonic acid. (NTMP), etc. HEDP and NTMP are effective because they have high solubility in the acidic region of hydrofluoric acid. Further, the etching liquid may be one which does not substantially contain such other components. The etchant "substantially does not contain" a component means that the content of the component in the etching solution is less than 1.0% by mass, preferably less than 0.5% by mass, more preferably less than 0.1% by mass.

Examples of the surfactant which can be used in the present invention include an amphoteric surfactant, a cationic surfactant, an anionic surfactant, and a nonionic surfactant. These may be used singly or in combination of two or more kinds as long as they do not impair the effects of the present invention. Examples of the amphoteric surfactant include 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine, coconut oil fatty amidinopropyl betaine, coconut oil alkyl alaninate, and laurel. Sodium guanyldipropionate. The cationic surfactant may, for example, be a quaternary ammonium salt (for example, lauryl trimethylammonium chloride), a higher amine hydrohalide (for example, hard bovine amine), or an alkyl pyridinium halide (for example, chlorinated 12). Alkylpyridinium). Examples of the anionic surfactant include alkyl sulfate salts, alkyl aryl sulfonates, alkyl ether sulfates, α-olefin sulfonates, alkyl sulfonates, alkyl benzene sulfonates, and the like. Alkyl naphthalene sulfonate, taurine surfactant, creatinate surfactant, isethionate surfactant, N-mercapto acid amino acid surfactant, monoalkyl Phosphate salts, higher fatty acid salts, and deuterated polypeptides. Examples of the nonionic surfactant include polyoxyalkylene alkyl ethers such as polyoxyethylene alkyl ethers; polyoxyethylene alkylphenyl ethers; polyoxyalkylene glycol derivatives; and polyoxyethylene alkyl groups; Amine, polyoxyethylene fatty decylamine, polyoxyethylene a polyoxyethylene derivative such as a fatty acid bisphenyl ether, a polyoxyethylene fatty acid ester or a polyoxyethylene sorbitan fatty acid ester; a monoglycerin fatty acid ester; a polyglycerin fatty acid ester; a sorbitan fatty acid ester; Sucrose fatty acid ester; polyoxyethylene castor oil; polyoxyethylene hydrogenated castor oil. For example, the alkyl group of any of the above surfactants may have a carbon number of 6 to 20 or 8 to 18.

The melting reaction of the glass by hydrofluoric acid is as follows.

SiO ₂ +6HF→2H ₂ O+H ₂ SiF ₆

When the concentration of hydrofluoric acid is increased, the etching rate is increased. However, if it is too fast, the "impurity of the fine pores or the etching liquid inside the grooves and the flow of the product generated by the etching" due to the ultrasonic irradiation becomes impossible. Fully catch up with this speed.

The concentration of the hydrofluoric acid contained in the etching solution is 0.05% by mass to 8.0% by mass, and the difference between the etching of the surface of the substrate and the inside of the substrate by the fine hole or the groove can be eliminated in the etching by the ultrasonic irradiation to form a fine Further, it is preferably from 0.10% by mass to 7.0% by mass, more preferably from 0.20% by mass to 5.0% by mass, in terms of a large inclination or a deep hole or groove. By lowering the concentration of hydrofluoric acid, the inclination of the formed pores can be improved, but if the concentration of hydrofluoric acid is excessively lowered, the etching rate becomes slow, and the treatment efficiency is unnecessarily deteriorated.

Fluoride and ruthenium fluoride which are formed by etching with glass by hydrofluoric acid have a low degree of melting, and thus tend to remain in fine pores or grooves, thereby hindering the progress of etching.

When the etching solution contains a mixed acid of hydrofluoric acid and one or more inorganic acids selected from the group consisting of nitric acid, hydrochloric acid, and sulfuric acid, H ⁺ is sufficiently present by ionization of nitric acid, hydrochloric acid, and sulfuric acid. HF The balance of H ⁺ +F ^- is biased to the left. Since free F ^- is reduced, and therefore inhibits the generation of fluoride and fluorides of silicon, and can be stably held inside of the flow of the etching solution or the fine pores due to the ultrasound irradiation generated by the etching of the grooves and generation of the product of . When the concentration of hydrofluoric acid is simply lowered, the free F ^- can be reduced, but the etching becomes difficult to perform. Therefore, it is preferable to suppress the generation of free F ^- by using a strong acid. When the concentration of nitric acid, hydrochloric acid, and sulfuric acid is increased, the etching rate is increased, and if it is too fast, the flow of the etching liquid in the fine pores or the grooves and the product generated by the etching due to the ultrasonic irradiation is promoted. It became impossible to fully catch up with this rate.

The surfactant is added to increase the wettability of the etching solution to the glass, whereby the etching solution can be easily introduced into and out of the fine pores or grooves. Further, by removing the dirt generated by the surfactant and preventing the re-adhesion of the fine particles or the product, it is possible to satisfactorily maintain the etching of the fine pores or the inside of the groove by the ultrasonic wave. In order to improve the effect of removing dirt, the amount of surfactant may also be increased, but if it is excessively increased, the labor caused by abnormality or rinsing due to foaming may be consumed. The surfactant can be obtained by adding 5 ppm.

The concentration of one or more inorganic acids (preferably nitric acid) selected from the group consisting of nitric acid, hydrochloric acid, and sulfuric acid in the etching solution is 2.0% by mass to 16.0% by mass, and etching can be performed by ultrasonic irradiation. The difference between the surface of the substrate and the inner surface of the fine hole or the groove is eliminated, and the hole or the groove having a large inclination and a deep inclination is preferably 2.5% by mass to 15.0% by mass. More preferably, it is 3.0% by mass to 14.0% by mass.

The content (mass concentration) of the surfactant contained in the etching solution is 5 ppm to 1000 ppm, and in the etching by the ultrasonic irradiation, the difference between the etching of the surface of the substrate and the inside of the fine hole or the groove can be eliminated, and It is preferably from 10 ppm to 800 ppm, more preferably from 15 ppm to 600 ppm, in terms of forming a finer and more inclined hole or groove. The content of the surfactant can be measured, for example, by high performance liquid chromatography (HPLC/High Performance Liquid Chromatography).

The etching time and the temperature of the etching liquid are selected depending on the shape of the metamorphic portion and the intended processing shape. Furthermore, the etching rate can be increased by increasing the temperature of the etching solution during etching. Further, the etching rate can also be adjusted according to the composition of the etching liquid. In the production method of the present invention, the etching rate is not particularly limited as long as it is expressed by the etching rate in the glass substrate other than the modified portion, and is preferably 0.1 to 9.0 μm/min, more preferably 0.2 to 7.0 μm/min. It is preferably 0.5 to 6.0 μm/min. Further, the diameter of the hole can be controlled in accordance with the etching conditions.

Since the etching time varies depending on the thickness of the glass plate, it is not particularly limited, but is preferably about 30 to 180 minutes. The temperature of the etching solution can be changed in order to adjust the etching rate, and is preferably about 5 to 45 ° C, more preferably about 15 to 40 ° C. That is, it is convenient to process at a temperature of 45 ° C or higher, but since the evaporation of the etching liquid is fast, it is not practical. That is, it is easy to process at a temperature of 5 ° C or lower, but it is not practical when the etching rate is extremely slow.

The etching solution of the present invention can be obtained by mixing the above components into a solvent. The solvent is not particularly limited, and is preferably water.

In the microstructured glass obtained by the manufacturing method of the present invention, the inclination of the hole is linearly higher on both the laser pulse incident surface (first surface) and the opposite surface (second surface). In particular, it is preferably 80 degrees or more, and more preferably 85 degrees or more. The method for measuring the inclination of the pores is as described in the following examples. Further, in the microstructure-attached glass obtained by the production method of the present invention, the opening diameter is preferably from 20 to 110 μm, more preferably from 25 to 100 μm, still more preferably from 30 to 95 μm. The opening diameter can be calculated from the image used when observing the inclination of the hole.

[Examples]

In the following, the present invention is more specifically described by the examples, but the present invention is not limited to the embodiments, and a large number of modifications can be made by those skilled in the art within the technical idea of the present invention.

[Example 1]

A glass substrate of 30 mm × 30 mm × t 0.52 mm composed of the components of the glass sample 1 of the following Table 1 was used as a sample.

<metamorphism forming step>

The formation of the metamorphic portion by laser was performed using a high repetition rate solid pulsed UV laser manufactured by Coherent: AVIA355-4500. At the third high harmonic Nd:YVO ₄ laser with a repetition rate of 25 kHz, the maximum laser power of about 6 W is obtained. The dominant wavelength of the third harmonic is 355 nm.

The laser pulse (pulse width 9 ns, power 1.2 W, beam diameter 3.5 mm) emitted from the laser device is expanded by 4 times by a beam expander, and a variable aperture which can be adjusted within a range of 5 to 15 mm in diameter is used. The enlarged beam was cut out, and the optical axis was adjusted by a mirror galvanometer, and the f θ lens having a focal length of 100 mm was incident on the inside of the glass plate. By changing the size of the aperture to change the diameter of the laser, the NA is varied to 0.020 to 0.075. At this time, the laser light was condensed at a position 0.15 mm from the upper surface of the glass plate by the physical length. The laser scanning was performed at a speed of 400 mm/s in such a manner that the irradiation pulses did not overlap.

After the laser beam was irradiated, it was confirmed by an optical microscope on the glass of the sample, and a portion different from the other portions was formed in the portion irradiated with the laser light. Although there is a difference in each glass, the metamorphic portion is mostly formed in a cylindrical shape, as shown in Fig. 3, from the vicinity of the upper surface of the glass to the vicinity of the lower surface.

The sample was irradiated with a laser by setting the repetition frequency to 10 to 25 kHz. Further, by changing the focus position in the thickness direction of the glass, the position (upper surface side or lower surface side) of the deteriorated portion formed on the glass is adjusted to be optimum.

<Supersonic irradiation etching step>

A 1 L container made of polyethylene was used as an etching bath, and the following components were blended at a ratio described in Table 2 using pure water as a solvent to prepare an etching solution.

‧ Hydrofluoric acid 46% Morita Chemical Industry

‧Nitrate 1.38 60% Kanto Chemical

‧High-performance nonionic surfactant NCW-1001 (polyoxyalkylene alkyl ether 30% aqueous solution) and pure pharmaceutical industry

Water was added to the ultrasonic bath to a specific water level, and an etching bath in which the etching liquid having the components of Table 2 was injected was placed therein, and the etching liquid was heated so that the liquid temperature became 30 °C. The sample (glass substrate) was placed in a box made of vinyl chloride and placed in an etching bath to irradiate ultrasonic waves of 40 kHz and 0.26 W/cm ² . Since the temperature of the etching liquid rises by ultrasonic irradiation, one part of the water of the ultrasonic wave tank is replaced and maintained at 30 ° C ± 2 ° C. The following procedure was carried out: the sample was lifted in the middle, the etching rate was determined from the change in the thickness of the substrate, and the etching time was determined so that the thickness of the substrate at the end of the etching was 440 mm, thereby obtaining a microstructured glass. The obtained sample was lifted, thoroughly rinsed with pure water, and dried with hot air.

The intensity of the ultrasonic wave is obtained by dividing the output (in W) by the bottom area of the etching groove (unit: cm ² ). As the ultrasonic groove, US-3R (model, output 120 W, oscillation frequency 40 kHz, manufactured by AS ONE Co., Ltd., groove size: W303 × D152 × H150 (unit: mm)) was used.

The sample was cut with a glass cutter, and the sections were sequentially polished using #1000 and #4000 abrasive pieces. When the altered portion that has been etched at this time is exposed to the cross section, the original contour cannot be observed, so that the amount of polishing is adjusted to prevent exposure. As an image measuring device, a CNC image measuring system NexivVMR-6555 (model, manufactured by Nikon Co., Ltd., magnification 8, field of view 0.58×0.44 (unit: mm)) was used, and the measuring device was used in the cross-sectional direction (thickness direction). The sample was observed so that the hole portion after etching was coincident with the focus. Using the tester, for Figure 4 The angle between the surface of the substrate and the side surface of the hole was measured at two points indicated by 51a and 51b in each surface, and the average value was taken as the inclination of the hole. Regarding the hole inclination, the laser pulse incident surface (hereinafter referred to as "first surface") is 86 degrees, and the opposite surface (hereinafter referred to as "second surface") is 86 degrees. Further, the opening diameter is calculated from the image used when observing the inclination of the hole. The actual observed image is shown in Fig. 5.

As shown in the first embodiment, ultrasonic etching using the etching liquid of the present invention can be performed on the finely altered portion and the processed hole formed on the glass to form a desired fineness and a large hole inclination. Deeper holes (straight holes).

By irradiating the ultrasonic waves, the pitting corrosion, the vibration acceleration, and the water flow promote the dispersion of the etching liquid and the product generated by the etching into the inside of the fine pores.

The etching is performed by adjusting the hydrofluoric acid concentration and the nitric acid concentration of the etching solution, and by elevating the etching liquid of the fine pores generated by the ultrasonic irradiation and the flow of the product formed by the etching. Speed is adjusted. Further, nitric acid can suppress the formation of a fluoride having a low degree of melting and a ruthenium fluoride in the fine pores, and stably maintain the etching liquid inside the fine pores generated by the ultrasonic irradiation and the product formed by the etching. The flow.

The surfactant can improve the wettability of the etching liquid to the glass, and the etching liquid can easily enter and exit the fine pores or the inside of the groove, and can prevent the product from adhering to the inside of the hole, and can be well maintained by the ultrasonic irradiation. The etching of the fine holes or the inside of the grooves is performed.

For these reasons, in the etching by ultrasonic irradiation, the difference between the etching of the surface of the substrate and the inside of the fine hole or the groove can be eliminated, and a fine but deeper and deeper hole can be formed (linear hole). ).

As a modification of the first embodiment, the glass used for the ultrasonic irradiation etching has The structure may be a through hole or a bottom as long as it can etch the deformed portion and structure formed on the glass to obtain a desired shape, and may be a hole or a groove.

The oscillation frequency of the ultrasonic wave of the first embodiment can be oscillated at a plurality of frequencies in sequence, or a plurality of frequencies can be simultaneously transmitted, and modulation can be performed.

When the intensity of the ultrasonic wave is increased, the inclination of the hole is increased, and if the temperature of the etching liquid is raised or the concentration of hydrofluoric acid or one or more inorganic acids selected from the group consisting of nitric acid, hydrochloric acid, and sulfuric acid is increased, the pores are The tilt is reduced and the etch rate is increased. Ultrasonic intensity, etching temperature, and etching solution blending ratio can be appropriately selected depending on the desired inclination and processing speed.

As a modification of the embodiment 1, hydrochloric acid or sulfuric acid may be used instead of the nitric acid blended into the etching solution.

As a modification of the first embodiment, the etching groove may be a general-purpose plastic other than polyethylene, or may be an engineering plastic as long as it is resistant to the etching liquid. In order to improve the transmission efficiency of the ultrasonic wave, the metal may be used. To cover the metal.

As a modification of the first embodiment, when the ultrasonic irradiation etching treatment is performed, the sample may be made parallel to the ultrasonic irradiation direction or may be made vertical, and the sample may be shaken in order to reduce the influence from the ultrasonic unevenness. The sample can also be rotated.

[Examples 2 to 6]

Ultrasonic irradiation etching was performed in the same manner as in Example 1 except that the etching conditions (etching liquid composition and etching rate) shown in Table 3 were changed, and a glass having a microstructure was produced. The etching conditions and evaluation results are shown in Table 3.

In Examples 2 to 6, the type of the sample (glass substrate) and the etch of the sample The thickness before etching and the thickness after etching were the same as in Example 1, and the composition of the etching liquid was different from that of Example 1.

In Example 2, the hydrofluoric acid concentration of the etching solution was reduced to 0.2% by mass, the nitric acid concentration was increased to 14.0% by mass, and the content of the surfactant was increased to 150 ppm as compared with the etching solution of Example 1. In Example 3, the hydrofluoric acid concentration of the etching liquid was increased to 5.0% by mass, and the nitric acid concentration was increased to 14.0% by mass as compared with the etching liquid of Example 1. Both of them obtained good through holes having a hole inclination of 85 degrees or more.

Further, in Example 4, the nitric acid concentration of the etching liquid was reduced to 3.0% by mass as compared with the etching liquid of Example 1, and in Example 5, the nitric acid concentration was increased as compared with the etching liquid of Example 1. To 14.0% by mass, the content of the surfactant was increased to 150 ppm. Both of them obtained good through holes having a hole inclination of 85 degrees or more.

Further, in Example 6, the content of the surfactant was increased to 500 ppm with respect to the etching liquid of Example 5, and as a result, a good through-hole having a pore inclination of 85 or more was obtained.

[Examples 7 to 9]

Ultrasonic irradiation etching was performed in the same manner as in Example 1 except that the etching conditions (etching liquid composition, ultrasonic irradiation conditions, and etching rate) shown in Table 4 were changed to produce a microstructured glass. The etching conditions and evaluation results are shown in Table 4.

In Examples 7 to 9, the type of the sample (glass substrate) and the thickness of the sample before etching and the thickness after etching were the same as in Example 1. The composition of the etching liquid was the same in Examples 7 to 9, and the conditions of the ultrasonic irradiation were different. In the seventh embodiment, an ultrasonic wave having an oscillation frequency of 28 kHz was irradiated during the etching treatment, and in the eighth embodiment, an ultrasonic wave having an oscillation frequency of 45 kHz was irradiated. Both of them produced pitting corrosion well, and a good through hole (straight hole) having a hole inclination of 85 degrees or more was obtained.

As the ultrasonic groove, the W-113 with the oscillation frequency can be changed (model, output 100W, oscillation frequency 28kHz/45kHz/100kHz, manufactured by Bento Electronics Co., Ltd., groove size: W240×D140×H100 (unit: mm)) .

In the ninth embodiment, an ultrasonic wave having an oscillation frequency of 100 kHz was irradiated. Pitting corrosion was hardly generated, and the hole inclination was 81 degrees on the first surface and 82 degrees on the second surface, and the hole inclination was lowered as compared with the result of the oscillation frequency lower than the frequency. The hole inclination can be increased by increasing the intensity of the ultrasonic wave, so that it is advantageous for a sample that is susceptible to damage, but an oscillation frequency higher than the frequency causes the threshold value of the pitting corrosion to rise sharply, which is not preferable.

[Comparative Example 1]

In the same sample (glass sample 1) as in Example 1, an etchant of 0.5% by mass of hydrofluoric acid and 3.0% by mass of nitric acid without using a surfactant was used without using ultrasonic waves. The stirring was carried out at 30 ° C, and etching was performed so as to have the same substrate thickness as in Example 1. The pore inclination was measured in the same manner as in Example 1 for the obtained glass. In the obtained glass, the inclination of the hole was 76 degrees on the first surface and 77 degrees on the second surface, and the through hole was significantly thinner in the middle. The actual observed image is shown in Fig. 6.

[Comparative Example 2]

In the same sample (glass sample 1) as in Example 1, an etching solution of 2.0% by mass of hydrofluoric acid and 3.0% by mass of nitric acid without adding a surfactant was irradiated at 40 ° C and 0.26 W/cm ² at 30 ° C. Sound waves are etched until the holes pass through. The pore inclination was measured in the same manner as in Example 1 for the obtained glass. In the obtained glass, the inclination of the hole was 72 degrees on the first surface and 73 degrees on the second surface, and the through hole was significantly thinner in the middle.

As described above, it has been confirmed that, according to the manufacturing method of the present invention, formation of a hole which suppresses low inclination can be obtained, and a hole or groove having higher linearity and deeper is formed in the thickness direction of the substrate. Microstructured microstructured glass.

[Examples 10 to 12]

A glass substrate of 30 mm × 30 mm × t 0.52 mm composed of the components of the glass samples 2 to 4 of Table 1 was used as a sample. Ultrasonic irradiation etching was performed in the same manner as in Example 1 except that the etching conditions shown in Table 5 were changed, and a microstructured glass was produced. The etching conditions and evaluation results are shown in Table 5. In either case, a good through hole having a hole inclination of 85 degrees or more was obtained. As an example, the image observed in Example 12 is shown in Fig. 7.

[Example 13]

For the same sample as in Example 1, hydrochloric acid (35.0-37.0% aqueous solution Kanto Chemical) was used instead of nitric acid as the inorganic acid, and the etching solution of hydrofluoric acid at 2.0% by mass, 6.0% by mass of hydrochloric acid, and 150 ppm of surfactant at 30 °C. In the middle, an ultrasonic wave of 40 kHz and 0.26 W/cm ^{2 was} irradiated and etched until the hole penetrated. A microstructured glass was obtained in the same manner as in Example 1 except that the conditions described in Table 6 were changed. In the obtained glass, the hole inclination was 85 degrees on the first surface and 88 degrees on the second surface, and a good through hole having a hole inclination of 85 degrees or more was obtained. The etching conditions and evaluation results are shown in Table 6.

[Embodiment 14]

A 30 mm × 30 mm × t 0.50 mm substrate of synthetic quartz (Shin-Etsu Chemical Industries) was used as a glass sample. The formation of the metamorphic portion by the laser irradiation was performed using a femtosecond laser with an output of 6 μJ, a spot diameter of the processing portion of Φ 9 μm, a pulse width of 800 fs, a repetition frequency of 2 kHz, and a processing speed of 0.2 mm/s. It was confirmed by an optical microscope that a portion having a diameter of about 10 μm or a fine void different from the other portions was formed in the portion irradiated with the laser light. The observed image is shown in Fig. 8.

Ultrasonic irradiation etching was performed in the same manner as in Example 1 except that the etching conditions (etching liquid composition, ultrasonic irradiation conditions, and etching rate) shown in Table 7 were changed. Micro-structured glass. In the obtained glass, the inclination of the hole was 90 degrees on the first surface and 89 degrees on the second surface, and a through hole substantially perpendicular to the synthetic quartz was obtained. The etching conditions and evaluation results are shown in Table 7. Further, the observed image is shown in Fig. 9.

[Comparative Example 3]

In the same sample as in Example 1, an ultrasonic wave of 40 kHz and 0.26 W/cm ^{2 was} irradiated in an etching solution of 14.0% by mass of hydrofluoric acid and 150 ppm of surfactant at 30 °C. Even if the etching was performed for 3 hours, the thickness of the glass substrate did not change, and the through holes were not obtained. If hydrofluoric acid is not added, the etching cannot progress, and a microstructure such as a hole or a groove cannot be formed in the glass.

[Comparative Example 4]

The same sample as in Example 1 was irradiated with an ultrasonic wave of 40 kHz and 0.26 W/cm ^{2 in an} etching solution of not less than 2.0% by mass of hydrofluoric acid of nitric acid and 150 ppm of surfactant at 30 ° C, and was etched to the hole. until. In the obtained glass, the inclination of the hole was 78 degrees on the first surface and 81 degrees on the second surface, and a through hole having a hole inclination of 80 degrees or more as in the case of adding nitric acid was not obtained.

[Comparative Example 5]

For the same sample as in Example 1, an ultrasonic wave of 40 kHz and 0.26 W/cm ^{2 was} irradiated in an etching liquid having a nitric acid concentration of 2.0% by mass of hydrofluoric acid, 20.0% by mass of nitric acid, and 150 ppm of a surfactant at 30 ° C. Etching until the hole penetrates. In the obtained glass, the first surface was 78 degrees with respect to the inclination of the hole, and the second surface was 79 degrees, and the through hole having a hole inclination of 80 degrees or more was not obtained.

[Industrial availability]

According to the method for producing a microstructured glass of the present invention, the formation of a hole for suppressing a low inclination is obtained, and a microstructure having a higher linearity and a deeper hole or groove is formed in the thickness direction of the substrate. glass.

Claims (10)

A method for producing a microstructured glass, comprising: an etching step of irradiating a glass with ultrasonic waves and etching, wherein the etching solution used in the etching step contains hydrofluoric acid, and is selected from the group consisting of nitric acid, hydrochloric acid and sulfuric acid; The inorganic acid and the surfactant in the above etching solution have a hydrofluoric acid concentration of 0.05% by mass to 8.0% by mass, a mineral acid concentration of 2.0% by mass to 16.0% by mass, and a surfactant content of 5 ppm. 1000ppm. The method for producing a microstructured glass according to the first aspect of the invention, further comprising the step of irradiating a laser with a laser pulse to form a modified portion or a processed hole before the etching step. The method for producing a microstructured glass according to claim 1 or 2, wherein the ultrasonic wave has an oscillation frequency of 100 kHz or less. The scope of the patent application of the method of manufacturing a glass attachment microstructure of any one of 1 to 3, wherein the intensity of the ultrasound is ^{0.10W / cm 2 ~ 5.0W / cm} 2. The method for producing a microstructured glass according to any one of claims 1 to 4, wherein the inorganic acid is nitric acid. The method for producing a micro-structured glass according to any one of claims 1 to 5, wherein the content of the surfactant is from 10 ppm to 800 ppm. The method for producing a microstructured glass according to any one of claims 1 to 6, wherein the surfactant is a nonionic surfactant. The method for producing a microstructured glass according to any one of claims 1 to 7, wherein the glass is a low alkali glass or alkali-free glass containing 0.1 mol% or more and less than 5.0 mol% of TiO ₂ . glass. The method for producing a micro-structured glass according to any one of claims 1 to 7, wherein the glass is a low alkali glass or an alkali-free glass containing 0.1 mol% or more and 2.0 mol% or less of CuO. The method for producing a microstructured glass according to any one of claims 1 to 9, wherein the microstructure on the glass after the etching step is a through hole, and the angle of the hole inclination is 80 degrees or more.