JPWO2017038075A1 - Manufacturing method of glass with microstructure - Google Patents

Abstract

The present invention provides a method for producing a glass with a microstructure in which formation of holes with a low gradient is suppressed, the straightness is higher in the thickness direction of the substrate, and microstructures such as deep holes or grooves are formed. The present invention has an etching process for etching glass by irradiating ultrasonic waves, and an etching solution used in the etching process is one or more inorganic acids selected from the group consisting of hydrofluoric acid; nitric acid, hydrochloric acid and sulfuric acid And a surfactant, in the etching solution, the hydrofluoric acid concentration is 0.05% by mass to 8.0% by mass, the inorganic acid concentration is 2.0% by mass to 16.0% by mass, and the interface It is related with the manufacturing method of the glass with a microstructure whose content of an activator is 5 ppm-1000 ppm.

Description

  The present invention relates to a method for producing a glass with a fine structure such as a through hole, a bottomed hole, and a groove by a laser pulse. More specifically, a glass in which the above-described fine structure is formed by forming an altered portion or a processed hole by laser irradiation to a glass substrate or the like, and removing the altered portion or the processed hole by ultrasonic irradiation etching. It relates to the manufacturing method.

  As a method for forming a desired hole or groove in a glass substrate by etching a modified substrate or a glass substrate in which minute processed holes are formed, for example, Patent Document 1 discloses that a modified portion is formed by irradiating a glass with a laser pulse. And the method of forming a hole or a groove | channel by etching using the etching liquid with a larger etching rate with respect to a modified part than the etching rate (henceforth an etching rate) with respect to the glass substrate is disclosed. Patent Document 2 discloses a method of processing a substrate by altering a portion of the substrate, irradiating the portion with a laser to form a minute processed hole, and then etching. That is, as shown in FIG. 1, a desired hole is formed by etching the glass substrate 11 in which the altered portion or minute processed hole is formed.

  In particular, when using a glass substrate or the like in which a through hole is formed for an electronic substrate application such as an interposer, the subsequent electrode forming process is taken into consideration, and in order to ensure a stable current, for example, the through hole It is desirable that the straightness is high.

  However, in the prior arts such as Patent Documents 1 and 2, the gradient of holes formed by etching becomes small, and deep holes may not be formed. Since the fine altered portion or the processed hole is expanded by etching to form a desired shape, the etching rate of the glass base material is not zero. In addition, since it is difficult for the etching solution to enter and exit the minute altered part or the processing hole, even if the rod, plate or propeller stirrer is rotated in the etching solution tank or the etching solution is stirred by bubbling, Advances closer to the surface of the substrate and is delayed later in the substrate. When the etching rate in the altered portion is larger than the portion other than the altered portion, the entry / exit or replacement of the etching solution occupies a large factor for the purpose of forming a hole having a large gradient and high straightness. It was not a thing. However, in the case of glass that has characteristics such that the difference in etching rate between the altered portion and the portion other than the altered portion is small, the altered portion near the substrate surface is etched before the altered portion is etched to the inside of the substrate. As the etching of the portion other than the altered portion proceeds and the difference in the etching rate is smaller, there is a case where the hole gradient of the altered portion near the substrate surface becomes smaller as shown in FIG.

JP 2011-37707 A JP 2001-105398 A

  The present invention has been made in view of the above problems, and its object is to suppress the formation of low-gradient holes provided in the fine structure in a method for producing a glass having a fine structure using a laser pulse in combination with the glass. It is to provide a method for producing glass in which the straightness is higher in the thickness direction of the substrate and a fine structure such as a deep hole or groove is formed. In particular, in a method of manufacturing a glass having a microstructure using laser pulses in combination, the formation of low-gradient holes provided in the microstructure is suppressed, and through holes with higher straightness are formed as the microstructure in the thickness direction of the substrate. It is to provide a method for producing a finished glass. Another object of the present invention is to provide an industrially advantageous method for producing a glass having a fine structure combined with a laser pulse.

The present invention
It has an etching process for etching by irradiating glass with ultrasonic waves,
An etching solution used in the etching step is hydrofluoric acid;
One or more inorganic acids selected from the group consisting of nitric acid, hydrochloric acid and sulfuric acid; and a surfactant,
In the etching solution, the hydrofluoric acid concentration is 0.05 mass% to 8.0 mass%, the inorganic acid concentration is 2.0 mass% to 16.0 mass%, and the surfactant content is 5 ppm to 1000 ppm,
A method for producing a microstructured glass is provided.

  By using the method for producing a glass with a fine structure of the present invention, a glass having a fine structure such as a deep hole or a groove is formed which suppresses the formation of low-gradient holes and has higher straightness in the thickness direction of the substrate. Can be manufactured. In particular, in a method of manufacturing a glass having a microstructure using laser pulses in combination, the formation of low-gradient holes provided in the microstructure is suppressed, and through holes with higher straightness are formed as the microstructure in the thickness direction of the substrate. It is to provide a method for producing a finished glass. Another object of the present invention is to provide an industrially advantageous method for producing a glass having a fine structure combined with a laser pulse.

FIG. 1 is a schematic cross-sectional view showing a conventional glass substrate etching method. FIG. 2 is a schematic cross-sectional view showing a conventional technique, particularly a method for etching a glass substrate when the difference in etching rate between the altered portion and the glass substrate is small. FIG. 3 is a schematic cross-sectional view illustrating a process of forming an altered portion according to the first embodiment. FIG. 4 is a schematic cross-sectional view of the glass substrate according to Example 1 for explaining a method for measuring a hole after etching. FIG. 5 is an image of the observation result of the cross section of the glass substrate according to Example 1 after etching. FIG. 6 is an image of the observation result of the cross section after etching of the glass substrate according to Comparative Example 1. FIG. 7 is an image of the observation result of the cross section of the glass substrate according to Example 12 after etching. FIG. 8 is an image of the observation result after the formation of the altered portion or the processed hole of the glass substrate according to Example 14 and before the etching. FIG. 9 is an image of the observation result of the cross section of the glass substrate according to Example 14 after etching.

  The manufacturing method of the glass with a microstructure of the present invention has an etching process of irradiating the glass with ultrasonic waves and etching, and the etching solution used in the etching process is selected from the group consisting of hydrofluoric acid; nitric acid, hydrochloric acid and sulfuric acid. One or more selected inorganic acids; and a surfactant. In the etching solution, the hydrofluoric acid concentration is 0.05% by mass to 8.0% by mass, and the inorganic acid concentration is 2.0% by mass to 16%. 0.0 mass%, and the surfactant content (mass concentration) is 5 ppm to 1000 ppm.

  The manufacturing method of the glass with a microstructure of the present invention preferably includes a step of forming a modified portion or a processed hole by irradiating the glass with a laser pulse before the etching step. That is, it is preferable that the glass used for the etching process has an altered portion or a processed hole formed before the etching process.

Before touching the details of the etching process, a process for forming a modified part or processed hole in the glass (hereinafter also referred to as “modified part forming process”) will be described.
In order to form a fine structure such as a through-hole in glass, the method described in JP-A-2008-156200 can be used as a step (method) for forming an altered portion that is expected to be removed by subsequent etching. . That is, a laser pulse having a wavelength λ is condensed by a lens and irradiated on the glass, thereby forming an altered portion or a processed hole in a portion of the glass irradiated with the laser pulse.

  As glass that can be used in the present invention (hereinafter also referred to as laser processing glass), quartz glass, borosilicate glass, aluminosilicate glass, soda lime glass, or titanium-containing silicate glass is suitable as the laser processing glass. Further, non-alkali glass that is substantially free of alkali components (alkali metal oxides) or low alkali glass that contains only a small amount of alkali components is also suitable as the laser processing glass. .

  Further, in order to effectively increase the absorption coefficient, the glass contains at least one oxide of a metal selected from Bi, W, Mo, Ce, Co, Fe, Mn, Cr, V and Cu as a coloring component. May be included.

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

Embodiment 1 of the aluminosilicate glass may have the following composition.
Expressed in mass%,
SiO ₂ 50~70%,
Al ₂ O ₃ 14-28%,
Na ₂ O 1-5%,
MgO 1-13%, and ZnO 0-14%,
A glass composition comprising:

Another embodiment 2 of the aluminosilicate glass may have the following composition.
Expressed in mass%,
SiO ₂ 56~70%,
Al ₂ O ₃ 7-17%,
B ₂ O ₃ 0-9%,
Li ₂ O 4~8%,
MgO 1-11%,
ZnO 4-12%,
TiO ₂ 0-2%,
Li ₂ O + MgO + ZnO 14-23%,
CaO + BaO 0-3%,
A glass composition comprising:

Another embodiment 3 of the aluminosilicate glass may have the following composition.
Expressed in mass%,
SiO ₂ 58~66%,
Al ₂ O ₃ 13-19%,
Li ₂ O 3 to 4.5%,
Na ₂ O 6-13%,
K ₂ O 0-5%,
R ₂ O 10-18% (where R ₂ O = Li ₂ O + Na ₂ O + K ₂ O),
MgO 0-3.5%,
CaO 1-7%,
SrO 0-2%,
BaO 0-2%,
RO 2-10% (however, RO = MgO + CaO + SrO + BaO),
TiO ₂ 0-2%,
CeO ₂ 0-2%,
Fe ₂ O ₃ 0-2%,
MnO 0 to 1% (however, TiO ₂ + CeO ₂ + Fe ₂ O ₃ + MnO = 0.01 to 3%),
SO ₃ 0.05~0.5%,
A glass composition comprising:

Another embodiment 4 of the aluminosilicate glass may have the following composition.
Expressed in mass%,
SiO ₂ 60~70%,
Al ₂ O ₃ 5-20%,
Li ₂ O + Na ₂ O + K ₂ O 5-25%,
Li ₂ O 0-1%,
Na ₂ O 3-18%,
K ₂ O 0~9%,
MgO + CaO + SrO + BaO 5-20%,
MgO 0-10%,
CaO 1-15%,
SrO 0-4.5%,
BaO 0-1%,
TiO ₂ 0-1%,
ZrO ₂ 0 to 1%,
A glass composition comprising:

Another embodiment 5 of the aluminosilicate glass may have the following composition.
Indicated by mass%
SiO ₂ 59~68%,
Al ₂ O ₃ 9.5-15%,
Li ₂ O 0-1%,
Na ₂ O 3-18%,
K ₂ O 0-3.5%,
MgO 0-15%,
CaO 1-15%,
SrO 0-4.5%,
BaO 0-1%,
TiO ₂ 0-2%,
ZrO ₂ 1-10%,
A glass composition comprising:

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

Embodiment 1 of the titanium-containing silicate glass may have the following composition.
Displayed in mol%
Comprises TiO ₂ 5 to 25%,
SiO ₂ + B ₂ O ₃ 50-79%,
Al ₂ O ₃ + TiO ₂ 5-25%,
Li ₂ O + Na ₂ O + K ₂ O + Rb ₂ O + Cs ₂ O + MgO + CaO + SrO + BaO 5-20%,
A glass composition.

In Embodiment 1 of the titanium-containing silicate glass,
Displayed in mol%
SiO ₂ 60~65%,
TiO ₂ 12.5-15%,
Na ₂ O 12.5-15%,
SiO ₂ + B ₂ O ₃ 70-75%,
It is preferable that

Furthermore, in Embodiment 1 of the titanium-containing silicate glass,
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
It is more preferable to satisfy (wherein the amount of each component is expressed in mol%).

Moreover, as other Embodiment 2 of a titanium containing silicate glass, it is good to have the following compositions. Displayed in mol%
B ₂ O ₃ 10-50%,
TiO ₂ 25-40%,
SiO ₂ + B ₂ O ₃ 20-50%,
Li ₂ O + Na ₂ O + K ₂ O + Rb ₂ O + Cs ₂ O + MgO + CaO + SrO + BaO 10-40%,
A glass composition.

As Embodiment 1 of a low alkali glass, it is good to have the following compositions.
Displayed in mol%
SiO ₂ 45~68%,
B ₂ O ₃ 2-20%,
Al ₂ O ₃ 3-20%,
TiO ₂ 0.1-5.0% (excluding 5.0%),
ZnO 0-9%,
A glass composition which is Li ₂ O + Na ₂ O + K ₂ O 0-2.0% (excluding 2.0%).

In Embodiment 1 of the low alkali glass, as a coloring component,
Displayed in mol%
CeO ₂ 0-3.0%,
Fe ₂ O ₃ 0 to 1.0%,
It is preferable to contain. Furthermore, in Embodiment 1 of the low alkali glass, an alkali-free glass substantially not containing an alkali metal oxide (Li ₂ O + Na ₂ O + K ₂ O) is more preferable.

The low alkali glass or non-alkali glass of Embodiment 1 contains TiO ₂ as an essential component. The content of TiO _{2 in} the low alkali glass or non-alkali glass is 0.1 mol% or more and less than 5.0 mol%, and is 0.2 because it is excellent in the smoothness of the inner wall surface of the hole obtained by laser irradiation. -4.0 mol% is preferable, 0.5-3.5 mol% is more preferable, 1.0-3.5 mol% is further more preferable. By appropriately including TiO ₂ in a low alkali glass or non-alkali glass having a specific composition, it becomes possible to form an altered portion even by irradiation of energy such as a relatively weak laser, and the altered portion is a post-process. It can be easily removed by ultrasonic irradiation etching. In addition, TiO ₂ has a binding energy substantially equal to that of ultraviolet light, and is known to absorb ultraviolet light. By appropriately including TiO ₂ , it is possible to control the coloration by utilizing the interaction with other colorants, as is generally known as charge transfer absorption. Therefore, by adjusting the content of TiO _2, the absorption for predetermined light can be made moderate. Since the glass has an appropriate absorption coefficient, it becomes easy to form an altered portion in which a hole is formed by etching. From these viewpoints, it is preferable that TiO ₂ is appropriately contained.

Moreover, the low alkali glass or non-alkali glass of Embodiment 1 may contain ZnO as an optional component. The content of ZnO in the low alkali glass or non-alkali glass is preferably 0 to 9.0 mol%, more preferably 1.0 to 8.0 mol%, and even more preferably 1.5 to 5.0 mol%. 1.5 to 3.5 mol% is particularly preferable. Since ZnO is a component that absorbs in the ultraviolet light region as in TiO ₂ , if it is contained, it is a component that brings about an effective action on the glass of the present invention.

The low alkali glass or non-alkali glass of Embodiment 1 may contain CeO ₂ as a coloring component. In particular, by using together with TiO ₂ , the altered portion can be formed more easily. The content of CeO _{2 in} the low alkali glass or non-alkali glass is preferably 0 to 3.0 mol%, more preferably 0.05 to 2.5 mol%, still more preferably 0.1 to 2.0 mol%. 0.2 to 0.9 mol% is particularly preferable.

Fe ₂ O _{3 is} also effective as a coloring component in the glass used in the present invention, and may be contained. In particular, the combined use of TiO ₂ and Fe ₂ O ₃ , or the combined use of TiO ₂ , CeO _2, and Fe ₂ O ₃ facilitates formation of the altered portion. The content of Fe ₂ O ₃ in the low alkali glass or non-alkali glass is preferably 0 to 1.0 mol%, more preferably 0.008 to 0.7 mol%, and 0.01 to 0.4 mol%. Further preferred is 0.02 to 0.3 mol%.

  The low alkali glass or non-alkali glass of Embodiment 1 is not limited to the components listed above, but the absorption coefficient of the glass at a predetermined wavelength (wavelength of 535 nm or less) is 1 to 50 due to the inclusion of an appropriate coloring component. / Cm, preferably 3 to 40 / cm.

Moreover, as other Embodiment 2 of a low alkali glass, it is good to have the following compositions.
Displayed in mol%
SiO ₂ 45~70%,
B ₂ O ₃ 2-20%,
Al ₂ O ₃ 3-20%,
CuO 0.1-2.0%,
TiO _{2 0 to} 15.0%,
ZnO 0-9.0%,
A glass composition which is Li ₂ O + Na ₂ O + K ₂ O 0-2.0% (excluding 2.0%).
Furthermore, in Embodiment 2 of the low alkali glass, an alkali-free glass substantially not containing an alkali metal oxide (Li ₂ O + Na ₂ O + K ₂ O) is more preferable.

The low alkali glass or non-alkali glass of Embodiment ₂ may contain TiO ₂ in the same manner as the low alkali glass or non-alkali glass of Embodiment 1. The content of TiO ₂ in the low alkali glass or non-alkali glass of the _second embodiment is 0 to 15.0 mol%, and 0 to 10.0 because of excellent smoothness of the inner wall surface of the hole obtained by laser irradiation. Mol% is preferable, 1-10.0 mol% is more preferable, 1.0-9.0 mol% is further more preferable, and 1.0-5.0 mol% is especially preferable.

Further, the low alkali glass or non-alkali glass of Embodiment 2 may contain ZnO. The content of ZnO in the low alkali glass or non-alkali glass of Embodiment 2 is 0 to 9.0 mol%, preferably 1.0 to 9.0 mol%, and 1.0 to 7.0 mol%. More preferred. Since ZnO is a component that absorbs in the ultraviolet light region as in TiO ₂ , if it is contained, it is a component that brings about an effective action on the glass of the present invention.

  Further, the low alkali glass or non-alkali glass of Embodiment 2 contains CuO. The content of CuO in the low alkali glass or alkali-free glass is preferably 0.1 to 2.0 mol%, more preferably 0.15 to 1.9 mol%, and 0.18 to 1.8 mol%. Further preferred is 0.2 to 1.6 mol%. By containing CuO, coloring occurs in the glass, and by setting the absorption coefficient at a predetermined laser wavelength to an appropriate range, it is possible to appropriately absorb the energy of the irradiation laser, and the altered portion that forms the basis of hole formation Can be easily formed.

  The low alkali glass or non-alkali glass of Embodiment 2 is not limited to the above-described components, but the absorption coefficient of the glass at a predetermined wavelength (wavelength of 535 nm or less) is 1 to 50 by containing an appropriate coloring component. / Cm, preferably 3 to 40 / cm.

  The low alkali glass or non-alkali glass of Embodiments 1 and 2 may contain MgO as an optional component. Among the alkaline earth metal oxides, MgO has the characteristics that it suppresses an increase in the thermal expansion coefficient and does not excessively lower the strain point, and may improve the solubility. The content of MgO in the low alkali glass or non-alkali glass is preferably 15.0 mol% or less, more preferably 12.0 mol% or less, further preferably 10.0 mol% or less, and 9.5 mol% or less. Particularly preferred. 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 non-alkali glass of Embodiments 1 and 2 may contain CaO as an optional component. CaO, like MgO, has the characteristics that it suppresses an increase in the thermal expansion coefficient and does not excessively lower the strain point, and may improve the solubility. The CaO content in the low alkali glass or non-alkali glass is preferably 15.0 mol% or less, more preferably 12.0 mol% or less, still more preferably 10.0 mol% or less, and 9.3 mol% or less. Particularly preferred. Further, the CaO content 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 non-alkali glass of Embodiments 1 and 2 may contain SrO as an optional component. SrO, like MgO and CaO, has the characteristics that it suppresses the increase in thermal expansion coefficient and does not excessively lower the strain point, and also improves the solubility, thus improving the devitrification characteristics and acid resistance. For this purpose, it may be contained. The content of SrO in the low alkali glass or non-alkali glass is preferably 15.0 mol% or less, more preferably 12.0 mol% or less, further preferably 10.0 mol% or less, and 9.3 mol% or less. Particularly preferred. The SrO content 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.

  “Substantially free” of a component 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. Means. In the present specification, the upper limit value and the lower limit value of the numerical ranges (content of each component, values calculated from each component, physical properties, etc.) can be appropriately combined.

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

  The thermal expansion coefficient is measured as follows. First, a cylindrical glass sample having a diameter of 5 mm and a height of 18 mm is prepared. This is heated from 25 ° C. to the yield point of the glass sample, and the thermal expansion coefficient is calculated by measuring the elongation of the glass sample at each temperature. An average value of thermal expansion coefficients in the range of 50 to 350 ° C. can be calculated to obtain an average thermal expansion coefficient. The average thermal expansion coefficient can be measured by a thermomechanical analyzer (TMA). The actual coefficient of thermal expansion was measured using a thermomechanical analyzer TMA4000SA manufactured by NETZSCH at a temperature increase rate of 5 ° C./min.

  There is no limitation in the shape of glass, for example, a glass plate is used. In the altered part forming step, it is not necessary to use so-called photosensitive glass, and the range of glass that can be processed is wide. That is, in the altered part forming step of the present invention, glass that does not substantially contain gold or silver can be processed.

  In particular, a highly rigid glass is less likely to be cracked on both the upper and lower surfaces of the glass when irradiated with a laser, and can be suitably processed by the altered portion forming step of the present invention. For example, a glass having a Young's modulus of 80 GPa or more is preferable.

The absorption coefficient α can be calculated by measuring the transmittance and reflectance of a glass substrate having a thickness t (cm). For a glass substrate having a thickness t (cm), a transmittance T (%) at a predetermined wavelength (wavelength 535 nm or less) and a reflectance R (%) at an incident angle of 12 ° are measured with a spectrophotometer (for example, JASCO Corporation). Measurement is performed using an ultraviolet-visible near-red spectrophotometer V-670). The absorption coefficient α is calculated from the obtained measured value using the following formula.
α = (1 / t) * ln {(100−R) / T}

  1-50 / cm is preferable and, as for the absorption coefficient (alpha) of the glass used for this invention, 3-40 / cm is more preferable.

  About the glass mentioned above, it may be marketed and can be obtained by purchasing them. Even if this is not the case, a desired glass can be produced by a known molding method (for example, overflow method, float method, slit draw method, casting method, etc.), and further by post-processing such as cutting and polishing. A glass composition of the shape can be obtained.

  In the altered part forming step, the altered part can be formed by one pulse irradiation. That is, in this step, the altered portion can be formed by irradiating the laser pulse so that the irradiation positions do not overlap. However, the laser pulses may be irradiated so that the irradiation pulses overlap.

  In the altered part forming step, the laser pulse is usually condensed by a lens so as to be focused inside the glass. For example, when forming a through-hole in a glass plate, the laser pulse is usually focused so as to be focused near the center in the thickness direction of the glass plate. When processing only the upper surface side (laser pulse incident side) of the glass plate, the laser pulse is usually focused so as to be focused on the upper surface side of the glass plate. Conversely, when processing only the lower surface side of the glass plate (the side opposite to the laser pulse incident side), the laser pulse is usually focused so as to be focused on the lower surface side of the glass plate. However, the laser pulse may be focused on the outside of the glass as long as the altered glass portion can be formed. For example, the laser pulse may be focused at a position away from the glass by a predetermined distance (for example, 1.0 mm) from the upper and lower surfaces of the glass plate. In other words, as long as an altered portion can be formed in the glass, the laser pulse is located within 1.0 mm from the upper surface of the glass in the front direction (the direction opposite to the traveling direction of the laser pulse) (including the upper surface of the glass). Alternatively, it may be focused to a position (including the position of the lower surface of the glass) or the position within 1.0 mm from the lower surface of the glass to the rear (the direction in which the laser pulse transmitted through the glass travels).

In the case of a nanosecond laser or an apparatus thereof, the pulse width of the laser pulse is preferably 1 to 200 ns (nanosecond), more preferably 1 to 100 ns, and further preferably 5 to 50 ns. In addition, when the pulse width is larger than 200 ns, the peak value of the laser pulse is lowered, and processing may not be performed well. The laser processing glass is irradiated with a laser beam having an energy of 5 to 100 μJ / pulse. By increasing the energy of the laser pulse, it is possible to increase the length of the altered portion in proportion to it. The beam quality M ₂ value of the laser pulse may be 2 or less, for example. By using a laser pulse having an M ₂ value of 2 or less, formation of minute pores or minute grooves is facilitated. In the following description, unless otherwise specified, the description regarding the laser relates to a nanosecond laser or an apparatus thereof.

In the altered portion forming step, the laser pulse may be a harmonic of an Nd: YAG laser, a harmonic of an Nd: YVO ₄ laser, or a harmonic of an Nd: YLF laser. The harmonic is, for example, a second harmonic, a third harmonic, or a fourth harmonic. The wavelength of the second harmonic of these lasers is around 532-535 nm. The wavelength of the third harmonic is in the vicinity of 355 to 357 nm. The wavelength of the fourth harmonic is in the vicinity of 266 to 268 nm. By using these lasers, glass can be processed at low cost.

As an apparatus used for the laser processing applied to the altered part forming step, for example, a high repetition solid-state pulse UV laser: AVIA355-4500 manufactured by Coherent is cited. This apparatus is a third harmonic Nd: YVO ₄ laser, and a maximum laser power of about 6 W can be obtained when the repetition frequency is 25 kHz. The wavelength of the third harmonic is 350 to 360 nm.

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

  As a typical optical system, the oscillated laser is expanded 2 to 4 times with a beam expander (at this time, the spot diameter of the processed portion is 7.0 to 14.0 mm), and the center portion of the laser is cut off with a variable iris. After that, the optical axis is adjusted with a galvanometer mirror, and the light is condensed on the glass while adjusting the focal position with an fθ lens of about 100 mm.

  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.

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 a beam diameter of a laser pulse when entering the lens, and means a diameter in a range where the intensity is [1 / e ² ] times the intensity at the center of the beam.

  In the altered part forming step, 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 related to the light condensing property of the laser irradiated on the glass. The smaller this value is, the more the laser is focused locally, and the more difficult it is to produce a uniform and long altered portion. . If this value is less than 7, the laser power becomes too strong in the vicinity of the beam waist, causing a problem that cracks are likely to occur inside the glass.

  In the altered portion forming step, pretreatment of the glass (for example, forming a film that promotes absorption of the laser pulse) is unnecessary before the laser pulse irradiation. However, such a process may be performed as long as the effect of the present invention is obtained.

  The numerical aperture (NA) may be varied from 0.020 to 0.075 by changing the diameter of the iris and changing the laser diameter. If the NA is too large, the laser energy is concentrated only in the vicinity of the focal point, and the altered portion is not formed effectively over the thickness direction of the glass.

  Furthermore, by irradiating a pulse laser having a small NA, a deteriorated portion that is relatively long in the thickness direction is formed by one pulse irradiation, which is effective in improving the tact time.

  The repetition frequency is preferably 10 to 25 kHz, and the sample is preferably irradiated with laser. Further, by changing the focal position in the thickness direction of the glass, the position (upper surface side or lower surface side) of the altered portion formed in the glass can be optimally adjusted.

  Furthermore, the laser output and the operation of the galvanometer mirror can be controlled by the control from the control PC, and the laser is irradiated onto the glass substrate at a predetermined speed based on the two-dimensional drawing data created by CAD software or the like. Can do.

  An altered portion different from other portions of the glass is formed in the portion irradiated with the laser. This altered portion can be easily identified with an optical microscope or the like. Although there is a difference for each glass depending on the composition, the altered portion is generally formed in a cylindrical shape. The altered portion reaches from the vicinity of the upper surface of the glass to the vicinity of the lower surface.

  The altered part is a sparse glass in a high temperature region where a photochemical reaction has occurred due to laser irradiation and a defect such as E ′ center or non-bridging oxygen has occurred, or due to rapid heating or rapid cooling by laser irradiation. It is considered that the site retained the structure.

  In the perforating technique using both laser irradiation and wet etching according to the altered part forming step of the present invention, the altered part can be formed by one-time laser pulse irradiation.

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

  Further, if necessary, the glass plate may be polished before etching to reduce the variation in the diameter of the altered portion. Since the effect of etching on the altered portion is weakened if the polishing is excessively performed, the polishing depth is preferably 1 to 20 μm from the upper surface of the glass plate.

  The size of the altered portion formed in the altered portion forming step varies depending on the beam diameter D of the laser when entering 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, for example, a diameter of about 5 to 200 μm and may be about 10 to 150 μm. Further, the depth of the altered portion varies depending on the laser irradiation conditions, the glass absorption coefficient, and the glass plate thickness, but may be, for example, about 50 to 300 μm.

  Moreover, it is possible to form a groove | channel by forming a some hole so that they may continue. In this case, a plurality of altered portions arranged in a line are formed by irradiating a plurality of laser pulses so as to be arranged in a line. Thereafter, a groove is formed by etching the altered portion. Irradiation positions of a plurality of laser pulses do not have to overlap, and holes formed by etching only need to connect adjacent holes.

  Further, the method for forming the altered portion is not limited to the above-described mode. For example, the altered portion or the processed hole may be formed by irradiation from the femtosecond laser apparatus described above. In the case of a femtosecond laser or an apparatus thereof, the conditions are not particularly limited as long as the effects of the present invention are exhibited. For example, the pulse width of the laser pulse is preferably 100 to 2000 fs (femtosecond), and more preferably 200 to 1000 fs. The repetition frequency is preferably 0.5 to 10 kHz, and the sample is preferably irradiated with a laser. The energy of the laser pulse is preferably 1 to 20 μJ / pulse. Moreover, it is preferable to adjust the optical system so that a laser pulse of 1 to 20 μJ per pulse forms a spot having a processed portion spot diameter of φ1 to 30 μm on the target glass. In the femtosecond laser or the apparatus thereof, a combination of the above-described suitable conditions as appropriate can be used.

  In addition, instead of the altered portion, a processed hole may be formed in advance in the glass substrate, and a final structure such as a through hole may be formed by an etching process that is a subsequent process. The step of forming the processed hole is performed by, for example, ablation by irradiating a suitable glass substrate (for example, a Ti-containing silicate glass having a high effect of lowering the processing threshold for laser processing) with laser having predetermined characteristics. Alternatively, the processing hole is formed by evaporation. As a laser apparatus to be used, for example, a YAG laser having a center wavelength of 266 nm or 355 nm (pulse width 5 to 8 nm), the focal length L (mm) of the lens is, for example, in the range of 50 to 500 mm, and the repetition frequency is It is preferable to irradiate the glass with a laser at 10 to 25 kHz for 0.5 to 10 seconds.

  Depending on the laser ablation, a hole or groove with a diameter of 10 to 100 μm or more can be formed by itself, so that it can be used in combination with subsequent etching to increase the hole diameter and improve straightness. There is also an effect of making the deformation portion of the glass such as debris around the portion inconspicuous and removing fine cracks.

  The method for forming the altered portion is not limited to the above as long as the microstructure can be formed on the glass substrate in combination with the subsequent etching step.

  The production method of the present invention includes an etching step of irradiating glass with ultrasonic waves. Ultrasonic cavitation, vibration acceleration, and water flow promote the dispersion of the etchant and the product from the etching into the fine holes or grooves. By irradiating with ultrasonic waves at the time of etching, the difference in etching progress between the substrate surface and the inside of the fine holes or grooves can be eliminated, and the fine holes or grooves can be formed with a large gradient (high straightness).

  When an ultrasonic wave is propagated in a liquid, cavitation, which is a phenomenon that creates a cavity in the liquid, occurs. Cavitation repeatedly increases and decreases pressure in a very short time, and pulls and compresses while shaking water molecules, thereby accelerating the movement of the etching solution or the product by etching to the inside of fine holes or grooves. However, as the oscillation frequency is increased, the threshold value for generating cavitation increases, and particularly when it exceeds 100 kHz, it rapidly increases exponentially and it becomes difficult to generate cavitation. The oscillation frequency of the ultrasonic irradiation etching is preferably in the range of 120 kHz or less from the point that the difference in etching progress between the substrate surface and the inside of the fine hole or groove can be eliminated, and the fine and large gradient can be formed. 10 to 120 kHz is more preferable, and 20 to 100 kHz is more preferable in that sufficient cavitation is generated in the etching solution. Two or more types of oscillation frequencies may be used in combination.

The intensity of the ultrasonic wave is not particularly limited, but is preferably 0.10~5.0W / cm ^2, more preferably ^{0.15~4.0W / cm 2, 0.20~3.0W / cm} 2 is Further preferred. If it is the intensity | strength of the ultrasonic wave in the said range, the intensity | strength of the ultrasonic wave to irradiate can be enlarged in the range which does not damage the to-be-processed glass. The ultrasonic intensity within the above range is selected because it is preferable because the effect of promoting the exchange of the etching solution in the vicinity of the inside and outside of the microstructure is increased. The intensity of the ultrasonic wave means the output (unit W) divided by the bottom area (unit cm ² ) of the etching tank.

  The ultrasonic treatment is not particularly limited, and a known device can be used. For example, W-113 (model number, output 100 W, oscillation frequency 28 kHz / 45 kHz / 100 kHz, manufactured by Honda Electronics Co., Ltd., tank dimensions: W240 × D140 × H100 (unit is mm)) or US-3R (model number, output 120 W, An oscillation frequency of 40 kHz, manufactured by AS ONE Co., Ltd., tank dimensions: W303 × D152 × H150 (unit: mm)) and the like can be used.

  In the etching step, in order to enable etching from only one side, a surface protective film agent may be applied and protected on the upper surface side or the lower surface side of the glass plate. As such a surface protective film agent, a commercially available product can be used, and examples thereof include silicate-II (manufactured by Trylaner International).

  The etching solution 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 solution may contain other components as long as the effects of the present invention are not hindered. Examples of such other components 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 because it prevents redeposition to the substrate surface by complexing metal ions. Examples of the chelating agent include dimethylglyoxime, dithizone, oxine, ethylenediaminetetraacetic acid, nitrilotriacetic acid, hydroxyethylidene diphosphonic acid (HEDP), nitrilotrismethylenephosphonic acid (NTMP), and the like. HEDP and NTMP are effective because of their high solubility in the hydrofluoric acid-based acidic region. The etching solution may be substantially free of these other components. The term “substantially does not contain” a certain component in the etching solution 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 0.1% by mass. Means less than%.

  Examples of the surfactant that can be used in the present invention include amphoteric surfactants, cationic surfactants, anionic surfactants, and nonionic surfactants. These may be used alone or in combination of two or more as long as they do not interfere with the effects of the present invention. Examples of amphoteric surfactants include 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyl betaine, coconut oil sodium alkylaminopropionate, sodium laurylaminodipropionate, and the like. . Examples of the cationic surfactant include quaternary ammonium salts (for example, lauryltrimethylammonium chloride), higher amine halogenates (for example, hard beef tallow amine), halogenated alkylpyridinium-based (for example, dodecylpyridinium chloride), and the like. It is done. As an anionic surfactant, alkyl sulfate ester salt, alkyl aryl sulfonate, alkyl ether sulfate ester salt, α-olefin sulfonate, alkyl sulfonate, alkyl benzene sulfonate, alkyl naphthalene sulfonate, taurine series Surfactants, sarcosinate surfactants, isethionate surfactants, N-acyl acidic amino acid surfactants, monoalkyl phosphate salts, higher fatty acid salts, acylated polypeptides and the like can be mentioned. Nonionic surfactants include polyoxyalkylene alkyl ethers such as polyoxyethylene alkyl ethers; polyoxyethylene alkyl phenyl ethers; polyoxyalkylene glycol derivatives; polyoxyethylene alkylamines, polyoxyethylene fatty acid amides, polyoxyethylenes Polyoxyethylene derivatives such as fatty acid bisphenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester; monoglycerin fatty acid ester; polyglycerin fatty acid ester; sorbitan fatty acid ester; sucrose fatty acid ester; polyoxyethylene castor oil; Examples include ethylene hardened castor oil. For example, the carbon number of the alkyl group of any of the above-described surfactants may be 6-20 or 8-18.

The glass melting reaction with hydrofluoric acid is described 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 the concentration is increased too much, the flow of the etching solution inside the fine holes or grooves caused by ultrasonic irradiation and the product due to the etching cannot be sufficiently caught up.

  The concentration of hydrofluoric acid contained in the etching solution is 0.05% by mass to 8.0% by mass, eliminating the difference in etching progress between the substrate surface and the inside of the fine holes or grooves in the etching by ultrasonic irradiation, 0.10 mass% to 7.0 mass% is preferable, and 0.20 mass% to 5.0 mass% is more preferable from the viewpoint of being fine and having a large gradient and capable of forming deep holes or grooves. Although it is possible to improve the gradient of the formed pores by lowering the hydrofluoric acid concentration, if the hydrofluoric acid concentration is lowered too much, the etching rate becomes slower and the processing efficiency becomes unnecessarily worse.

  Since the fluoride and silicofluoride generated by etching the glass with hydrofluoric acid have low solubility, they tend to stay inside the minute holes or grooves and inhibit the progress of the 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 due to ionization of nitric acid, hydrochloric acid, and sulfuric acid. ⇔H ^{+ +} F ^- parallel is leftward. Since the free F ⁻ is reduced, the generation of fluoride and silicofluoride is suppressed, and the flow of the etching solution inside the fine holes or grooves by ultrasonic irradiation and the product by etching can be stably maintained. When the concentration of hydrofluoric acid is simply lowered, free F ⁻ can be reduced, but etching is difficult to proceed. Therefore, it is better to suppress the generation of free F ^{− with} a strong acid. If the concentration of nitric acid, hydrochloric acid and sulfuric acid is increased, the etching rate is increased. If the concentration is too high, the flow of the etching solution inside the fine holes or grooves due to the ultrasonic irradiation and the product due to the etching are not sufficiently promoted.

  By adding a surfactant to improve the wettability of the etchant to the glass, the etchant can easily enter and exit the fine holes or grooves. Further, the removal of dirt by the surfactant and the effect of preventing the reattachment of particles and products can keep the etching progress inside the fine holes or grooves by ultrasonic irradiation well. In order to enhance the effect of removing dirt, the amount of the surfactant may be increased. However, if it is excessively increased, troubles due to foaming and excessive labor are required. The effect can be obtained by adding 5 ppm of a surfactant.

  The concentration of one or more inorganic acids (preferably nitric acid) selected from the group consisting of nitric acid, hydrochloric acid and sulfuric acid contained in the etching solution is 2.0% by mass to 16.0% by mass, and is obtained by ultrasonic irradiation. In etching, the difference in etching progress between the substrate surface and the inside of the fine holes or grooves is eliminated, and from 2.5 mass% to 15.0 mass% from the point that fine, large gradient and deep holes or grooves can be formed. Preferably, 3.0 mass% to 14.0 mass% is more preferable.

  The content (mass concentration) of the surfactant contained in the etching solution is 5 ppm to 1000 ppm. In etching by ultrasonic irradiation, the difference in etching progress between the substrate surface and the inside of the fine holes or grooves is eliminated, and is fine. 10 ppm to 800 ppm is preferable and 15 ppm to 600 ppm is more preferable from the viewpoint that the gradient is large and deep holes or grooves can be formed. The content of the surfactant can be measured using, for example, high performance liquid chromatography (HPLC / High Performance Liquid Chromatography).

  The etching time and the temperature of the etching solution are selected according to the shape of the altered portion and the target processing shape. Note that the etching rate can be increased by increasing the temperature of the etching solution during etching. The etching rate can also be adjusted by the composition of the etching solution. In the production method of the present invention, the etching rate is not particularly limited when expressed by the etching rate in the glass substrate other than the altered portion, but is preferably 0.1 to 9.0 μm / min, and preferably 0.2 to 7.0 μm / min. Min is more preferable, and 0.5 to 6.0 μm / min is more preferable. Furthermore, the diameter of the hole can be controlled by the etching conditions.

  The etching time depends on the thickness of the glass plate and is not particularly limited, but is preferably about 30 to 180 minutes. The temperature of the etching solution can be changed to adjust the etching rate, preferably about 5 to 45 ° C, more preferably about 15 to 40 ° C. Processing is possible even at a temperature of 45 ° C. or higher, but it is not practical because of the rapid volatilization of the etching solution. Processing is possible even at a temperature of 5 ° C. or lower, but it is not practical when the etching rate is extremely low.

  The etching solution of the present invention can be obtained by mixing the above-described components in a solvent. The solvent is not particularly limited, but water is preferable.

  In the glass with a microstructure obtained by the production method of the present invention, the hole gradient is 80 degrees or more from the viewpoint of high straightness on both the laser pulse incident surface (first surface) and the opposite surface (second surface). What becomes becomes more preferable, and what becomes 85 degree | times or more is more preferable. The method for measuring the pore gradient is as described in the examples described later. Moreover, 20-110 micrometers is preferable in the glass with a microstructure obtained by the manufacturing method of this invention, 25-100 micrometers is more preferable, 30-95 micrometers is further more preferable. The opening diameter can be calculated from the image used for observation of the hole gradient.

  EXAMPLES Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples at all, and many variations are within the technical idea of the present invention. This is possible by those with ordinary knowledge.

[Example 1]
A glass substrate of 30 mm × 30 mm × t 0.52 mm composed of the components of glass sample 1 shown in Table 1 below was used as a sample.

<Deformed part formation process>
For the formation of the altered portion by the laser, a high repetition solid-state pulse UV laser: AVIA355-4500 manufactured by Coherent was used. This is a third harmonic Nd: YVO ₄ laser, and a maximum laser power of about 6 W can be obtained when the repetition frequency is 25 kHz. The dominant wavelength of the third harmonic is 355 nm.

  A laser pulse (pulse width 9 ns, power 1.2 W, beam diameter 3.5 mm) emitted from the laser device is expanded four times by a beam expander, and this expanded beam is adjusted within a range of 5 to 15 mm in diameter. The optical axis was adjusted with a galvano mirror, and the light was made incident on the inside of the glass plate with an fθ lens having a focal length of 100 mm. The laser diameter was changed by changing the size of the iris to vary the NA from 0.020 to 0.075. At this time, the laser beam was condensed at a position separated by 0.15 mm in physical length from the upper surface of the glass plate. The laser beam was scanned at a speed of 400 mm / second so that the irradiation pulses did not overlap.

  After the laser light irradiation, it was confirmed with an optical microscope that a modified portion different from other portions was formed in the glass portion of the sample in the portion irradiated with the laser light. Although there is a difference for each glass, the altered portion is generally formed in a cylindrical shape, and as shown in FIG. 3, it has reached the vicinity of the lower surface from the vicinity of the upper surface of the glass.

  The repetition frequency was 10 to 25 kHz, and the sample was irradiated with laser. Moreover, the position (upper surface side or lower surface side) of the altered portion formed on the glass was optimally adjusted by changing the focal position in the thickness direction of the glass.

<Ultrasonic irradiation etching process>
The etching liquid was produced by mix | blending the following component in the ratio described in Table 2 by making a 1L container made from polyethylene into an etching tank, and using pure water as a solvent.
・ Hydrofluoric acid 46% Morita Chemical Industry ・ Nitric acid 1.38 60% Kanto Chemical ・ High-performance nonionic surfactant NCW-1001 (Polyoxyalkylene alkyl ether 30% aqueous solution) Wako Pure Chemical Industries

Water was put into an ultrasonic bath to a predetermined water level, an etching bath containing an etching solution having the components shown in Table 2 was set therein, and the etching solution was heated so that the temperature of the solution became 30 ° C. The sample (glass substrate) was placed on a cassette made of vinyl chloride, placed in an etching tank, and irradiated with ultrasonic waves of 40 kHz and 0.26 W / cm ² . Since the temperature of the etching solution was increased by the ultrasonic irradiation, a part of the water in the ultrasonic bath was replaced and kept at 30 ° C. ± 2 ° C. The sample was pulled up halfway, the etching rate was determined from the change in substrate thickness, and the etching time was determined so that the substrate thickness at the end of etching was 440 μm. The obtained sample was pulled up, rinsed thoroughly with pure water, and dried with hot air.
The intensity of the ultrasonic wave was obtained by dividing the output (unit W) by the bottom area (unit cm ² ) of the etching tank. As an ultrasonic tank, US-3R (model number, output 120 W, oscillation frequency 40 kHz, manufactured by AS ONE Corporation, tank dimensions: W303 × D152 × H150 (unit: mm)) was used.

  The sample was cut with a glass cutter, and the cross-sections were polished sequentially with # 1000 and # 4000 polishing sheets. At this time, if the etched altered portion is exposed in the cross section, the original contour cannot be observed. Therefore, the amount of polishing is adjusted so as not to be exposed. As an image measuring device, a CNC image measuring system NexivVMR-6555 (model number, manufactured by Nikon Corporation, magnification 8, visual field 0.58 × 0.44 (unit: mm)) is used, and the sample is cross-sectional direction ( Observed from the thickness direction), the hole after the etching was focused. The angle formed by the two substrate surfaces 51a and 51b shown in 51a and 51b on each surface of FIG. 4 and the hole side surface was measured by the measuring instrument, and the average was defined as the hole gradient. The hole gradient was 86 degrees on the laser pulse incident surface (hereinafter referred to as “first surface”) and 86 degrees on the opposite surface (hereinafter referred to as “second surface”). The opening diameter was calculated from the image used for observation of the hole gradient. An actually observed image is shown in FIG.

  As shown in Example 1, by performing ultrasonic irradiation etching using the etching solution of the present invention on finely altered portions and processed holes formed in glass, a desired fine and hole gradient is obtained. Large and deep holes (straight holes) could be formed.

  By irradiating with ultrasonic waves, cavitation, vibration acceleration, and water flow promote the dispersion of the etching solution and the product by etching into the fine holes.

  By adjusting the hydrofluoric acid concentration and nitric acid concentration of the etching solution, the etching rate is adjusted so as to catch up with the flow promotion of the fine hole etching solution and the product by etching by ultrasonic irradiation. Nitric acid can suppress the formation of fluoride and silicofluoride having low solubility in fine pores, and can stably maintain the flow of the etching solution inside the fine pores by ultrasonic irradiation and the product by etching.

  The surfactant improves the wettability of the etchant to the glass, facilitates the entry and exit of the etchant into the fine holes or grooves, prevents the product from adhering to the inside of the hole, and by ultrasonic irradiation. The etching progress inside the fine holes or grooves can be kept good.

  For these reasons, in etching by ultrasonic irradiation, the difference in etching progress between the substrate surface of the fine hole or groove and the inside is eliminated, and a deep hole (straight hole) having a large gradient can be formed while being fine.

  As a modification of Example 1, the structure of the glass used for the ultrasonic irradiation etching has a through-hole, a bottomed hole, a hole, as long as a desired shape can be obtained by etching the altered portion and structure formed in the glass, It may be a groove.

  The ultrasonic oscillation frequency according to the first embodiment may be generated by sequentially oscillating a plurality of frequencies, transmitting a plurality of frequencies simultaneously, or modulating the plurality of frequencies.

  Increasing the intensity of the ultrasonic wave improves the pore gradient, increasing the temperature of the etching solution, or increasing the concentration of one or more inorganic acids selected from the group consisting of hydrofluoric acid; or nitric acid, hydrochloric acid and sulfuric acid. Instead, the etching rate is increased. Depending on the desired gradient and processing speed, the ultrasonic intensity, etching temperature, and etchant composition ratio can be selected appropriately.

  As a modification of the first embodiment, hydrochloric acid or sulfuric acid may be used instead of nitric acid mixed in the etching solution.

  As a modification of the first embodiment, the etching tank may be a general-purpose plastic other than polyethylene or an engineering plastic as long as it is resistant to the etching solution, and may be a metal or a metal to increase the ultrasonic wave propagation efficiency. You may have done.

  As a modification of the first embodiment, the sample may be parallel or perpendicular to the ultrasonic irradiation direction during the ultrasonic irradiation etching process, or the sample may be reduced in order to reduce the influence of ultrasonic unevenness. It may be rotated or rotated.

[Examples 2 to 6]
Except having changed into the etching conditions (etching liquid composition and etching rate) shown in Table 3, ultrasonic irradiation etching was performed similarly to Example 1, and the glass with a fine structure was manufactured. Table 3 shows the etching conditions and evaluation results.

In Examples 2 to 6, the type of the sample (glass substrate), the thickness of the sample before etching, and the thickness after etching are the same as in Example 1, and the composition of the etching solution is different from that in Example 1.
In Example 2, compared with the etching liquid of Example 1, the hydrofluoric acid concentration of the etching liquid was reduced to 0.2% by mass, the nitric acid concentration was increased to 14.0% by mass, and the surfactant content was increased. Increased to 150 ppm. In Example 3, compared with the etching liquid of Example 1, the hydrofluoric acid concentration of the etching liquid was increased to 5.0 mass%, and the nitric acid concentration was increased to 14.0 mass%. In both cases, good through-holes having a hole gradient of 85 degrees or more were obtained.

  Further, in Example 4, the nitric acid concentration of the etching solution was reduced to 3.0 mass% compared to the etching solution of Example 1, and in Example 5, the nitric acid concentration was 14 compared to the etching solution of Example 1. The content of the surfactant was increased to 150 ppm. In both cases, good through-holes having a hole gradient of 85 degrees or more were obtained.

  Furthermore, in Example 6, when the content of the surfactant was increased to 500 ppm with respect to the etching solution of Example 5, good through holes having a hole gradient of 85 degrees or more were obtained.

[Examples 7 to 9]
Ultrasonic irradiation etching was performed in the same manner as in Example 1 except that the etching conditions (etching solution composition, ultrasonic irradiation conditions, and etching rate) shown in Table 4 were changed, and a glass with a microstructure was manufactured. Table 4 shows the etching conditions and evaluation results.

In Examples 7 to 9, the type of the sample (glass substrate), the thickness of the sample before etching, and the thickness after etching are the same as in Example 1. The composition of the etching solution is the same in Examples 7 to 9, and the conditions for ultrasonic irradiation are different. In Example 7, ultrasonic waves with an oscillation frequency of 28 kHz were applied during the etching process, and in Example 8, ultrasonic waves with an oscillation frequency of 45 kHz were applied. In both cases, cavitation occurred frequently, and good through holes (straight holes) having a hole gradient of 85 degrees or more were obtained.
As an ultrasonic tank, W-113 (model number, output 100 W, oscillation frequency 28 kHz / 45 kHz / 100 kHz, manufactured by Honda Electronics Co., Ltd., tank dimensions: W240 × D140 × H100 (unit: mm)) whose oscillation frequency can be changed is used. Using.

  In Example 9, ultrasonic waves with an oscillation frequency of 100 kHz were applied. Cavitation did not occur so much, and the hole gradient was 81 degrees on the first surface and 82 degrees on the second surface, which was lower than the result obtained at a lower oscillation frequency. Since the pore gradient can be improved by increasing the intensity of the ultrasonic wave, it is beneficial for a sample that is easily damaged, but an oscillation frequency higher than this is not preferable because the threshold for cavitation rises rapidly.

[Comparative Example 1]
The same sample as in Example 1 (Glass Sample 1) was added with an etchant containing 0.5% by mass of hydrofluoric acid and 3.0% by mass of nitric acid without addition of a surfactant at 30 ° C. The resulting mixture was stirred and etched so as to have the same substrate thickness as in Example 1. For the obtained glass, the pore gradient was measured in the same manner as in Example 1. In the obtained glass, the hole gradient was 76 degrees on the first surface and 77 degrees on the second surface, and the through holes were clearly constricted. An actually observed image is shown in FIG.

[Comparative Example 2]
The same sample (glass sample 1) as in Example 1 was prepared by adding an etching solution containing 2.0% by mass of hydrofluoric acid and 3.0% by mass of nitric acid without adding a surfactant at 30 ° C., 40 kHz, 0.26 W / Etching was performed until ultrasonic waves of cm ² were irradiated and the holes penetrated. For the obtained glass, the pore gradient was measured in the same manner as in Example 1. In the obtained glass, the hole gradient was 72 degrees on the first surface and 73 degrees on the second surface, and the through holes were clearly constricted.

  As described above, the manufacturing method of the present invention suppresses the formation of low-gradient holes, has a higher straightness in the thickness direction of the substrate, and has a microstructured glass formed with a microstructure such as deep holes or grooves. It was confirmed that it was obtained.

[Examples 10 to 12]
A glass substrate of 30 mm × 30 mm × t 0.52 mm composed of the components of glass samples 2 to 4 in Table 1 was used as a sample. Except having changed into the etching conditions shown in Table 5, ultrasonic irradiation etching was performed like Example 1 and the glass with a fine structure was manufactured. Table 5 shows etching conditions and evaluation results. In any case, good through-holes having a hole gradient of 85 degrees or more were obtained. As an example, an image observed for Example 12 is shown in FIG.

[Example 13]
The same sample as Example 1 was used, using hydrochloric acid (35.0-37.0% aqueous solution Kanto Chemical) as an inorganic acid instead of nitric acid, hydrofluoric acid 2.0% by mass, hydrochloric acid 6.0% by mass, interface Etching was performed until the hole penetrated by irradiating ultrasonic waves of 40 kHz and 0.26 W / cm ² at 30 ° C. with an etching solution of 150 ppm of activator. Except having changed into the conditions described in Table 6, the glass with a microstructure was obtained like Example 1. In the obtained glass, the hole gradient was 85 degrees on the first surface and 88 degrees on the second surface, and good through holes having a hole gradient of 85 degrees or more were obtained. Table 6 shows the etching conditions and evaluation results.

[Example 14]
A synthetic quartz (Shin-Etsu Chemical Co., Ltd.) 30 mm × 30 mm × t 0.50 mm substrate was used as the glass sample. Formation of the altered portion by laser was performed using a femtosecond laser at an output of 6 μJ, a processed portion spot diameter of Φ9 μm, a pulse width of 800 fs, a repetition frequency of 2 kHz, and a processing speed of 0.2 mm / second. It was confirmed with an optical microscope that an altered portion or a fine cavity having a diameter of about 10 μm different from other portions was formed in the portion irradiated with the laser light. The observed image is shown in FIG.

  Ultrasonic irradiation etching was performed in the same manner as in Example 1 except that the etching conditions (etching solution composition, ultrasonic irradiation conditions, and etching rate) shown in Table 7 were changed, and a glass with a fine structure was manufactured. In the obtained glass, the hole gradient was 90 degrees on the first surface and 89 degrees on the second surface, and a through hole almost perpendicular to the synthetic quartz was obtained. Table 7 shows the etching conditions and evaluation results. Moreover, the observed image is shown in FIG.

[Comparative Example 3]
The same sample as in Example 1 was irradiated with ultrasonic waves of 40 kHz and 0.26 W / cm ² at 30 ° C. with an etching solution of 14.0% by mass of nitric acid and 150 ppm of surfactant without adding hydrofluoric acid. Even when etching was carried out for 3 hours, the thickness of the glass substrate did not change, and no through-holes were obtained. If hydrofluoric acid is not added, etching does not proceed, and a fine structure 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 ultrasonic waves of 40 kHz, 0.26 W / cm ² at 30 ° C. in an etching solution containing 2.0% by mass of hydrofluoric acid and 150 ppm of surfactant without adding nitric acid, Etching was performed until it penetrated. In the obtained glass, the pore gradient was 78 degrees on the first surface and 81 degrees on the second surface, and through-holes with a pore gradient of 80 degrees or more as in the case of adding nitric acid were not obtained.

[Comparative Example 5]
The same sample as in Example 1 was increased in nitric acid concentration, hydrofluoric acid 2.0 mass%, nitric acid 20.0 mass%, surfactant 150 ppm etching solution at 30 ° C., 40 kHz, 0.26 W / cm ^2. Were etched until the holes penetrated. In the obtained glass, the hole gradient was 78 degrees on the first surface and 79 degrees on the second surface, and through-holes with a hole gradient of 80 degrees or more were not obtained.

  The method for producing a glass with a microstructure of the present invention suppresses the formation of low-gradient holes, and a glass with a microstructure having a higher straightness in the thickness direction of the substrate and having a microstructure such as deep holes or grooves is obtained. It is done.

Claims (10)

It has an etching process for etching by irradiating glass with ultrasonic waves,
An etching solution used in the etching step is hydrofluoric acid;
One or more inorganic acids selected from the group consisting of nitric acid, hydrochloric acid and sulfuric acid; and a surfactant,
In the etching solution, the hydrofluoric acid concentration is 0.05 mass% to 8.0 mass%, the inorganic acid concentration is 2.0 mass% to 16.0 mass%, and the surfactant content is 5 ppm to 1000 ppm,
Manufacturing method of glass with fine structure.   Furthermore, the manufacturing method of the glass with a microstructure of Claim 1 which has the process of irradiating a laser pulse to glass and forming a modified part or a processed hole before an etching process.   The manufacturing method of the glass with a fine structure of Claim 1 or 2 whose oscillation frequency of an ultrasonic treatment is 100 kHz or less. The intensity of the ultrasonic wave is ^{0.10W / cm 2 ~5.0W / cm 2} , the production method of the fine structure with a glass according to any one of claims 1 to 3.   The manufacturing method of the glass with a microstructure of any one of Claims 1-4 whose inorganic acid is nitric acid.   The manufacturing method of the glass with a microstructure of any one of Claims 1-5 whose content of surfactant is 10 ppm-800 ppm.   The manufacturing method of the glass with a microstructure according to any one of claims 1 to 6, wherein the surfactant is a nonionic surfactant. The manufacturing method of the glass with a microstructure according to any one of claims 1 to 7, wherein the glass is a low alkali glass or non-alkali glass containing TiO ₂ in an amount of 0.1 mol% or more and less than 5.0 mol%. .   The manufacturing method of the glass with a microstructure of any one of Claims 1-7 whose glass is the low alkali glass or alkali free glass containing 0.1 mol% or more and 2.0 mol% or less CuO.   The method for producing a glass with a microstructure according to any one of claims 1 to 9, wherein the microstructure in the glass after the etching step is a through-hole, and the angle of the hole gradient is 80 degrees or more.

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