JP6753347B2 - A method for manufacturing a glass substrate, a method for forming holes in a glass substrate, and a device for forming holes in a glass substrate. - Google Patents

Description

The present invention relates to a method for manufacturing a glass substrate, a method for forming holes in a glass substrate, and an apparatus for forming holes in a glass substrate.

Conventionally, there has been known a technique of forming fine holes in a glass substrate by irradiating the glass substrate with a laser beam from a laser oscillator.

For example, Patent Document 1 describes a laser processing machine for fine hole processing of glass, which includes a pulse CO ₂ laser oscillator and various optical systems including a condenser lens.

JP 2013-241301

In the above-mentioned laser processing machine for fine hole processing of glass described in Patent Document 1, a pulse-shaped CO ₂ laser beam emitted from a pulse CO ₂ laser oscillator is applied to a glass substrate. By irradiating the CO ₂ laser beam, the glass substrate is locally heated, and fine holes are formed at the irradiation position.

Here, in such a conventional hole processing technique, cracks may occur in the glass substrate during or after the hole processing. Therefore, when actually hole machining, a CO ₂ laser beam irradiation time (i.e., CO ₂ laser beam of pulse width) is adjusted to be as short as possible.

However, if the irradiation time of the CO ₂ laser beam is shortened, it becomes difficult to form sufficiently deep holes in the glass substrate. Therefore, when it is necessary to form a deep hole, the peak power of the pulsed CO ₂ laser beam must be increased as much as possible.

However, when the peak power of the CO ₂ laser beam is increased, the impact applied to the glass substrate at the time of irradiation is increased, which eventually results in cracks in the glass substrate.

The present invention has been made in view of such a background, and the present invention provides a method for producing a glass substrate having holes having a desired depth, which can significantly suppress the occurrence of cracks. With the goal. Another object of the present invention is to provide a method for forming holes having a desired depth in a glass substrate, which can significantly suppress the occurrence of cracks. Furthermore, an object of the present invention is to provide an apparatus for forming holes having a desired depth in a glass substrate, which can significantly suppress the occurrence of cracks.

The present invention is a method for manufacturing a glass substrate having holes having a depth of d (μm) or more.
It has a step of irradiating a glass substrate with a laser beam oscillated from a CO ₂ laser oscillator for an irradiation time of t (μsec) to form holes in the glass substrate.
The laser beam is focused by a condenser lens and then irradiated to the glass substrate.
When the power and beam cross-sectional area of the laser beam immediately before entering the condenser lens are P ₀ and S, respectively, the following equation (1)

P _d = P ₀ / S (1)

The power density P _d (W / cm ² ) represented by is 600 W / cm ² or less.
The irradiation time t (μsec) is

t ≧ 10 × d / (P _d ) ^1/2 Eq. (2)

A manufacturing method that meets the requirements is provided.

Further, in the present invention, it is a method of forming holes having a depth of d (μm) or more in a glass substrate.
It has a step of irradiating a glass substrate with a laser beam oscillated from a CO ₂ laser oscillator for an irradiation time of t (μsec) to form holes in the glass substrate.
The laser beam is focused by a condenser lens and then irradiated to the glass substrate.
When the power and beam cross-sectional area of the laser beam immediately before entering the condenser lens are P ₀ and S, respectively, the following equation (1)

P _d = P ₀ / S (1)

The power density P _d (W / cm ² ) represented by is 600 W / cm ² or less.
The irradiation time t (μsec) is
t ≧ 10 × d / (P _d ) ^1/2 Eq. (2)

A method is provided that meets the requirements.

Further, in the present invention, it is an apparatus for forming holes having a depth of d (μm) or more in a glass substrate.
A CO ₂ laser oscillator that oscillates a laser beam,
A condenser lens that concentrates the laser beam on a glass substrate,
Have,
By irradiating the glass substrate with the laser beam for an irradiation time t (μsec), holes are formed in the glass substrate.
When the power and beam cross-sectional area of the laser beam immediately before entering the condenser lens are P ₀ and S, respectively, the following equation (1)

P _d = P ₀ / S (1)

The power density P _d (W / cm ² ) represented by is 600 W / cm ² or less.
The irradiation time t (μsec) is
t ≧ 10 × d / (P _d ) ^1/2 Eq. (2)

A device is provided that meets the requirements.

The present invention can provide a method for producing a glass substrate having holes having a desired depth, which can significantly suppress the occurrence of cracks. Further, the present invention can provide a method for forming holes having a desired depth in a glass substrate, which can significantly suppress the occurrence of cracks. Further, the present invention can provide an apparatus for forming holes having a desired depth in a glass substrate, which can significantly suppress the occurrence of cracks.

It is a figure which showed schematic structure of the hole forming apparatus by one Embodiment of this invention. It is a figure which showed the example of the output waveform of the laser beam oscillated from the continuous wave CO ₂ laser oscillator schematically. It is a figure which showed the example of the output waveform of the laser beam oscillated from the pulse CO ₂ laser oscillator schematically.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(Method for manufacturing a glass substrate according to an embodiment of the present invention)
In one embodiment of the present invention, a method for manufacturing a glass substrate having holes having a desired depth d (μm) or more (hereinafter, referred to as “first manufacturing method”) is provided.

The first manufacturing method is
A step of irradiating a glass substrate with a laser beam oscillated from a CO ₂ laser oscillator for an irradiation time of t (μsec) or more to form holes having a desired depth d (μm) or more in the glass substrate. Have.

Hereinafter, the first manufacturing method will be described in detail with reference to FIG.

(Hole forming device)
FIG. 1 schematically shows a configuration of a hole forming apparatus (hereinafter, referred to as “first hole forming apparatus”) that can be used when carrying out the first manufacturing method.

As shown in FIG. 1, the first hole forming apparatus 100 includes a laser oscillator 110, various optical systems, and a stage 160.

In the example shown in FIG. 1, the optical system is arranged in order from the laser oscillator 110 side with the beam expander 120, the wave plate 130, the aperture 140, and the condenser lens 150. However, the arrangement of this optical system is merely an example, and optical members other than the condenser lens 150 may be omitted.

The laser oscillator 110 is a CO ₂ laser oscillator, and can irradiate the CO ₂ laser beam 113 toward the beam expander 120.

The laser oscillator 110 may be a pulse CO ₂ laser oscillator or a continuous wave CO ₂ laser oscillator. In the former case, a pulsed CO ₂ laser beam is emitted from the laser oscillator 110, and in the latter case, a continuous wave CO ₂ laser beam is emitted from the laser oscillator 110.

The wavelength of the CO ₂ laser beam (hereinafter, simply referred to as “laser beam”) 113 may be in the range of, for example, 9.2 μm to 9.8 μm. The diameter of the laser beam 113 at this stage is φ ₁ , and the beam cross-sectional area is S ₁ .

The beam expander 120 has a role of expanding the laser beam 113 irradiated from the laser oscillator 110 at a predetermined rate. For example, in the example shown in FIG. 1, the beam expander 120, the diameter phi ₁ and the incident laser beam 113 in the beam cross-sectional area _{S 1,} expanding the laser beam 123 of diameter phi ₂ and the beam cross-sectional area _{S 2.} Here, φ ₁ <φ ₂ and S ₁ <S ₂ .

The enlargement ratio is, for example, in the range of 1.5 times to 4.0 times.

The wave plate 130 is arranged on the opposite side of the laser oscillator 110 via the beam expander 120. The wave plate 130 is composed of, for example, a 1/4 wave plate or the like.

When the laser beam 123 is linearly polarized, the wave plate 130 can convert it into a circularly polarized laser beam. Hereinafter, the laser beam emitted from the wave plate 130 will be referred to as "laser beam 133". When the laser beam irradiated to the glass substrate is circularly polarized, the quality of the holes formed on the glass substrate (for example, the verticality of the holes and the perfect circle) are compared with the case where the linearly polarized laser beam is irradiated. Degree etc.) is improved.

The aperture 140 is located on the opposite side of the laser oscillator via the wave plate 130. The aperture 140 has a role of adjusting the incident laser beam 133 into a predetermined shape.

For example, in the example shown in FIG. 1, the aperture 140, the incident laser beam 133 of diameter phi ₂ and the beam cross-sectional area _{S 2,} to adjust the laser beam 143 of diameter phi ₃ and beam cross-sectional area _{S 3.} Here, φ ₃ <φ ₂ and S ₃ <S ₂ .

The condenser lens 150 is arranged on the opposite side of the laser oscillator via the aperture 140.

As shown in FIG. 1, the condensing lens 150 has a role of condensing the incident laser beam 143 at a predetermined position on the member to be processed, that is, the glass substrate 190.

The stage 160 has a role of supporting the glass substrate 190. The stage 160 may be a stage that can move in the XY directions.

As described above, at least one member of the beam expander 120, the wave plate 130, and the aperture 140 may be omitted.

When forming holes in the glass substrate 190 by using the first hole forming apparatus 100 having such a configuration, first, the glass substrate 190 is placed on the stage 160.

The glass substrate 190 has a first surface 192 and a second surface 194 facing each other. The glass substrate 190 is arranged on the stage 160 so that the side of the second surface 194 is the side of the stage 160.

The stage 160 may have a means for fixing the glass substrate 190. For example, the stage 160 may have a suction mechanism, and the glass substrate 190 may be suction-fixed to the stage 160. By using such a stage 160, the misalignment of the glass substrate 190 during processing is suppressed.

Next, the laser beam 113 is irradiated from the laser oscillator 110 toward the beam expander 120.

The laser beam 113 irradiated to the beam expander 120 is expanded here to become an expanded laser beam 123, and the expanded laser beam 123 is irradiated to the wave plate 130. The magnifying laser beam 123 irradiated to the wave plate 130 is converted into circularly polarized light here, and the circularly polarized laser beam 133 is irradiated to the aperture 140. The shape of the circularly polarized laser beam 133 irradiated to the aperture 140 is adjusted here to become the laser beam 143.

After that, the laser beam 143 that has passed through the aperture 140 is irradiated to the condenser lens 150. The laser beam 143 is focused by the condensing lens 150 to become a focused laser beam 153 having a desired shape, and is irradiated to the irradiation position 196 of the glass substrate 190.

The focused laser beam 153 raises the temperature of the irradiation position 196 of the glass substrate 190 and the portion immediately below it, and removes substances existing in this region. As a result, a hole 198 is formed at the irradiation position 196 of the glass substrate 190.

As shown in FIG. 1, the hole 198 formed in the glass substrate 190 may be a through hole. Alternatively, the hole 198 may be a non-through hole.

After that, by moving the stage 160 on the XY plane and performing the same operation, a plurality of holes 198 can be formed in the glass substrate 190.

Here, the first manufacturing method, the power of the laser beam 143 immediately before entering the condenser lens 150 and _P 0 (W), the beam area of the laser beam 143 immediately before entering the condenser lens 150 _{S 3} Then, the following equation (3)

P _d = P ₀ / S ₃ (3)

The laser beam 143 represented by the above has a feature that the power density P _d (W / cm ² ) is 600 W / cm ² or less.

Power density _P d (W / cm ²⁾ is preferably at 320W / cm ² or less, more preferably 160 W / cm ² or less, particularly preferably 80W / cm ² or less. Further, the power density P _d (W / cm ² ) is preferably 5 W / cm ² or more, and more preferably 10 W / cm ² or more in order to proceed with the hole processing.

Further, in the first manufacturing method, when the depth of the holes formed in the glass substrate 190 is d (μm) or more, the time during which the focused laser beam 153 is irradiated to the glass substrate 190, that is, the irradiation time t (μsec). ) Is

t ≧ 10 × d / (P _d ) ^1/2 Eq. (4)

It has the characteristic of satisfying. Here, P _d is the above-mentioned power density P _d (W / cm ² ).

For example, in the first manufacturing method, when a hole having a depth d = 50 μm or more is formed in the glass substrate 190, assuming that the right side of the equation (4) is t _min (hereinafter referred to as “minimum irradiation time”), the depth is Assuming that d = 50 μm and power density P _d (W / cm ² ) = 600 W / cm ² , the minimum irradiation time is t _min ≈ 20 μsec. Therefore, in this case, the time t for the focused laser beam 153 to irradiate the glass substrate 190 is selected to be 20 μsec or more.

Further, for example, when a hole having a depth d = 100 μm or more is formed in the glass substrate 190, the depth d = 100 μm, the power density P _d (W / cm ² ) = 600 W / cm ² , and the minimum irradiation time t _min ≈ It becomes 41 μsec. Therefore, in this case, the time t for the focused laser beam 153 to irradiate the glass substrate 190 is selected to be 41 μsec or more.

As described above, in the first manufacturing method, the power density P _d (W / cm ² ) of the laser beam 143 immediately before being irradiated to the condenser lens 150 is sufficiently suppressed to, for example, 600 W / cm ² or less. .. Therefore, the impact of the focused laser beam 153 irradiated on the glass substrate 190 can be sufficiently reduced, and the occurrence of cracks on the glass substrate 190 can be significantly suppressed.

Further, the focused laser beam 153 irradiates the glass substrate 190 for a sufficiently long time. Therefore, even if the power density P _d (W / cm ² ) is relatively small, holes having a desired depth d or more can be formed in the glass substrate 190.

Due to the above effects, in the first production method, it is possible to form the holes 198 having a desired depth d or more in a state where the occurrence of cracks is significantly suppressed.

Further, in the first manufacturing method, since the power density Pd (W / cm ² ) can be made relatively small, it can be said that the occurrence of cracks can be prevented even if the irradiation is performed for a long time.

(Laser oscillator 110)
As described above, the first hole forming apparatus has a CO ₂ laser oscillator 110, and the laser oscillator 110 may be a continuous wave CO ₂ laser oscillator or a pulse CO ₂ laser oscillator.

Of these, the continuous wave CO ₂ laser oscillator can oscillate a continuous wave CO ₂ laser beam.

FIG. 2 schematically shows an example of the output waveform of the laser beam oscillated from the continuous wave CO ₂ laser oscillator. In FIG. 2, the horizontal axis is the time T (sec) and the vertical axis is the power of the laser beam. The vertical axis represents the power density (W / cm ² ) obtained by dividing the power of the laser beam by the beam cross-sectional area S of the laser beam. However, the same can be said when the vertical axis is represented by the power of the laser beam.

As shown in FIG. 2, the laser beam 212 oscillated from the continuous wave CO ₂ laser oscillator has a flat output waveform that does not substantially change with time T. Therefore, the time average of the power density of the laser beam 212, that is, the average power density (expressed by _Pave ) is substantially equal to the peak power density of the laser beam 212 (expressed by P _max ).

On the other hand, the pulsed CO ₂ laser oscillator can oscillate a pulsed CO ₂ laser beam.

FIG. 3 schematically shows an example of the output waveform of the laser beam oscillated from the pulse CO ₂ laser oscillator. In FIG. 3, the horizontal axis and the vertical axis are the same as in the case of FIG.

As shown in FIG. 3, the laser beam 214 oscillated from the pulsed CO ₂ laser oscillator has a pulsed output waveform. Therefore, _(represented by _{P ave)} average power density of the laser beam 214 becomes a value different from the peak power density of the laser beam 214 _(represented by _{P max).}

In this way, the laser beam 212 oscillated from the continuous wave CO ₂ laser oscillator has _Pave = P _max , whereas the laser beam 214 oscillated from the pulse CO ₂ laser oscillator has _Pave ≠ P _max. There is a feature that becomes.

In the present application, it should be noted that the power density P _d (W / cm ² ) of the laser beam 143 represented by the above equation (3) means the maximum power of the output waveform, that is, P _max . Therefore, when the laser oscillator 110 is a continuous wave CO ₂ laser oscillator, the power density P _d (W / cm ² ) of the laser beam 143 is substantially equal to its average power density, but the laser oscillator 110 is a pulse CO ₂ laser. In the case of an oscillator, the power density P _d (W / cm ² ) of the laser beam 143 represents a value different from its average power density.

Further, the irradiation time t (μsec) in the above equation (4) is, for example, when the focused laser beam 153 has a continuous wave as shown in FIG. 2, the focused laser beam 153 actually irradiates the glass substrate 190. Means total time. On the other hand, when the focused laser beam 153 has a pulsed output waveform as shown in FIG. 3, the irradiation time t (μsec) is such that when the irradiation time t is shorter than the pulse width, the focused laser beam 153 is actually glass. It means the total time of irradiation on the substrate 190, but when the irradiation time t is longer than the pulse width, it is the time including the non-oscillation time between pulses.

With reference to FIGS. 1 to 3, the method for manufacturing a glass substrate according to the embodiment of the present invention and the apparatus for forming holes in the glass substrate have been described above. However, the above description is merely an example, and the present invention may be carried out in other forms. For example, the present invention can also be applied to a method of forming non-through holes in a glass substrate.

Next, examples of the present invention will be described. In the following description, Examples 1 to 6 are Examples, and Examples 7 to 12 are Comparative Examples.

(Example 1)
Using the first hole forming apparatus as shown in FIG. 1 described above, holes were formed in the glass substrate to produce a hole-containing glass substrate. In addition, in the obtained glass substrate, the presence or absence of cracks and the depth of holes (penetration / non-penetration) were evaluated. The depth of the holes was evaluated as follows. The desired hole depth d is set to the thickness of the glass substrate. It was determined that the desired depth d was obtained if the holes formed in the glass substrate were penetrated, and it was determined that the desired depth d was not obtained if the holes were not penetrated.

In the first hole forming apparatus, a continuous wave CO ₂ laser oscillator (DIAMOND-GEM100L-9.6: manufactured by Coherent) was used as the laser oscillator. Using this continuous wave CO ₂ laser oscillator was oscillating a continuous-wave CO ₂ laser beam of the beam diameter phi ₁ = 3.5 mm.

The beam diameter phi ₁ of the continuous-wave CO ₂ laser beam, using a beam expander, expanded to 3.5 times (therefore, the beam diameter _{φ 2 = 3.5mm × 3.5 = 12.25mm} ). A λ / 4 wave plate was used as the wave plate. The aperture, after passing through the aperture, were used as the beam diameter phi ₃ of the laser beam is 9 mm.

An aspherical lens having a focal length of 25 mm was used as the condenser lens. The peak power (= average power) of the laser beam between the aperture and the condenser lens was 50 W. Therefore, the power density P _d of the laser beam at this position is about 79 W / cm ² .

As the glass substrate, 50 mm × 50 mm non-alkali glass was used. The thickness of the glass substrate was 100 μm. Therefore, in Example 1, the desired hole depth d is 100 μm. The irradiation time t of the laser beam on the glass substrate was 120 μsec.

Here, in Example 1, the minimum irradiation time t _min corresponding to the right side of the above equation (4) is about 113 μsec. Therefore, the minimum irradiation time t _min <irradiation time t.

The number of holes formed in the glass substrate was 10,000.

As a result of observing the glass substrate after forming the holes, no abnormality such as cracks was observed in the glass substrate.

Also, the hole was through.

(Example 2)
Holes were formed in the glass substrate by the same method as in Example 1, and a hole-containing glass substrate was produced. Moreover, in the obtained glass substrate, the presence or absence of cracks and the depth of holes were evaluated.

However, in this example 2, the thickness of the glass substrate was set to 300 μm. Therefore, the desired hole depth d was set to 300 μm. The irradiation time t was 380 μsec.

Here, in Example 2, the minimum irradiation time t _min corresponding to the right side of the above equation (4) is about 338 μsec. Therefore, the minimum irradiation time t _min <irradiation time t.

As a result of observing the glass substrate after forming the holes, no abnormality such as cracks was observed in the glass substrate.

Also, the hole was through.

(Example 3)
Holes were formed in the glass substrate by the same method as in Example 1, and a hole-containing glass substrate was produced. Moreover, in the obtained glass substrate, the presence or absence of cracks and the depth of holes were evaluated.

However, in Example 3, the peak power (= average power) of the laser beam was set to 100 W between the aperture and the condenser lens. Therefore, the power density P _d of the laser beam at this position is about 157 W / cm ² .

The irradiation time t was 80 μsec.

Here, in Example 3, the minimum irradiation time t _min corresponding to the right side of the above equation (4) is about 80 μsec. Therefore, the minimum irradiation time t _min = irradiation time t.

As a result of observing the glass substrate after forming the holes, no abnormality such as cracks was observed in the glass substrate.

Also, the hole was through.

(Example 4)
Holes were formed in the glass substrate by the same method as in Example 3, and a hole-containing glass substrate was produced. Moreover, in the obtained glass substrate, the presence or absence of cracks and the depth of holes were evaluated.

However, in this example 4, the thickness of the glass substrate was set to 300 μm. Therefore, the desired hole depth d was set to 300 μm. The irradiation time t was set to 260 μsec.

Here, in Example 4, the minimum irradiation time t _min corresponding to the right side of the above equation (4) is about 239 μsec. Therefore, the minimum irradiation time t _min <irradiation time t.

As a result of observing the glass substrate after forming the holes, no abnormality such as cracks was observed in the glass substrate.

Also, the hole was through.

(Example 5)
Holes were formed in the glass substrate by the same method as in Example 1, and a hole-containing glass substrate was produced. Moreover, in the obtained glass substrate, the presence or absence of cracks and the depth of holes were evaluated.

However, in this Example 5, a pulse CO ₂ laser oscillator (manufactured by Coherent) was used as the laser oscillator. Using this pulsed CO ₂ laser oscillator was oscillating a pulsed CO ₂ laser beam of the beam diameter phi ₁ = 3.5 mm.

Further, the average power of the laser beam was set to 67 W and the peak power of the laser beam was set to 201 W between the aperture and the condenser lens. Therefore, the power density P _d of the laser beam between the aperture and the condenser lens is about 316 W / cm ² .

The irradiation time t was set to 56 μsec.

Here, in Example 5, the minimum irradiation time t _min corresponding to the right side of the above equation (4) is about 56 μsec. Therefore, the minimum irradiation time t _min = irradiation time t.

As a result of observing the glass substrate after forming the holes, no abnormality such as cracks was observed in the glass substrate.

Also, the hole was through.

(Example 6)
Holes were formed in the glass substrate by the same method as in Example 5, and a hole-containing glass substrate was produced. Moreover, in the obtained glass substrate, the presence or absence of cracks and the depth of holes were evaluated.

However, in this example 6, the thickness of the glass substrate was set to 300 μm. Therefore, the desired hole depth d was set to 300 μm. The irradiation time t was 170 μsec.

Here, in Example 6, the minimum irradiation time t _min corresponding to the right side of the above equation (4) is about 169 μsec. Therefore, the minimum irradiation time t _min <irradiation time t.

As a result of observing the glass substrate after forming the holes, no abnormality such as cracks was observed in the glass substrate.

Also, the hole was through.

(Example 7)
Holes were formed in the glass substrate by the same method as in Example 5, and a hole-containing glass substrate was produced. Moreover, in the obtained glass substrate, the presence or absence of cracks and the depth of holes were evaluated.

However, in this Example 7, the average power of the laser beam was set to 130 W and the peak power of the laser beam was set to 390 W between the aperture and the condenser lens. Therefore, the power density P _d of the laser beam between the aperture and the condenser lens is about 613 W / cm ² .

The irradiation time t on the glass substrate was 41 μsec.

Here, in Example 7, the minimum irradiation time t _min corresponding to the right side of the above equation (4) is about 40 μsec. Therefore, the minimum irradiation time t _min <irradiation time t.

As a result of observing the glass substrate after forming the holes, it was confirmed that the glass substrate had cracks. The crack occurrence rate per 10,000 holes was 2%.

The hole was through.

(Example 8)
Holes were formed in the glass substrate by the same method as in Example 7, and a hole-containing glass substrate was produced. Moreover, in the obtained glass substrate, the presence or absence of cracks and the depth of holes were evaluated.

However, in this Example 8, the thickness of the glass substrate was set to 300 μm. Therefore, the desired hole depth d was set to 300 μm. The irradiation time t was 122 μsec.

Here, in Example 8, the minimum irradiation time t _min corresponding to the right side of the above equation (4) is about 121 μsec. Therefore, the minimum irradiation time t _min <irradiation time t.

As a result of observing the glass substrate after forming the holes, it was confirmed that the glass substrate had cracks. The crack occurrence rate per 10,000 holes was 5%.

The hole was through.

(Example 9)
Holes were formed in the glass substrate by the same method as in Example 5, and a hole-containing glass substrate was produced. Moreover, in the obtained glass substrate, the presence or absence of cracks and the depth of holes were evaluated.

However, in this Example 9, the average power of the laser beam is 400 W and the peak power of the laser beam is 1200 W between the aperture and the condenser lens. Therefore, the power density P _d of the laser beam between the aperture and the condenser lens is about 1886 W / cm ² .

The irradiation time t was set to 23 μsec.

Here, in Example 9, the minimum irradiation time t _min corresponding to the right side of the above equation (4) is about 23 μsec. Therefore, the minimum irradiation time t _min = irradiation time t.

As a result of observing the glass substrate after forming the holes, it was confirmed that the glass substrate had cracks. The crack occurrence rate per 10,000 holes was 50%.

The hole was through.

(Example 10)
Holes were formed in the glass substrate by the same method as in Example 9, and a hole-containing glass substrate was produced. Moreover, in the obtained glass substrate, the presence or absence of cracks and the depth of holes were evaluated.

However, in this example 10, the thickness of the glass substrate was set to 300 μm. Therefore, the desired hole depth was set to 300 μm. The irradiation time t was 72 μsec.

Here, in Example 10, the minimum irradiation time t _min corresponding to the right side of the above equation (4) is about 69 μsec. Therefore, the minimum irradiation time t _min <irradiation time t.

As a result of observing the glass substrate after forming the holes, it was confirmed that the glass substrate had cracks. The crack occurrence rate per 10,000 holes was 80%.

The hole was through.

(Example 11)
Holes were formed in the glass substrate by the same method as in Example 1, and a hole-containing glass substrate was produced. Moreover, in the obtained glass substrate, the presence or absence of cracks and the depth of holes were evaluated.

The irradiation time t was 30 μsec.

Here, in Example 11, the minimum irradiation time t _min corresponding to the right side of the above equation (4) is about 113 μsec. Therefore, the minimum irradiation time t _min > irradiation time t.

As a result of observing the glass substrate after forming the holes, no abnormality such as cracks was observed in the glass substrate.

However, since the minimum irradiation time t _min > irradiation time t, a hole having a desired depth could not be obtained, and the hole was not penetrated.

(Example 12)
Holes were formed in the glass substrate by the same method as in Example 10 to produce a hole-containing glass substrate. Moreover, in the obtained glass substrate, the presence or absence of cracks and the depth of holes were evaluated.

The irradiation time t was 35 μsec.

Here, in Example 12, the minimum irradiation time t _min corresponding to the right side of the above equation (4) is about 69 μsec. Therefore, the minimum irradiation time t _min > irradiation time t.

As a result of observing the glass substrate after forming the holes, it was confirmed that the glass substrate had cracks. The crack occurrence rate per 10,000 holes was 40%.

Further, since the minimum irradiation time t _min > irradiation time t, a hole having a desired depth could not be obtained, and the hole was not penetrated.

Table 1 below summarizes the manufacturing method of the hole-containing glass substrate and the evaluation results in each example.

表１に示すように、例１〜例６に示したような孔含有ガラス基板の製造方法を採用することにより、クラックの発生が有意に抑制され、所望の深さの孔が形成できることが確認された。

As shown in Table 1, it was confirmed that by adopting the method for producing a hole-containing glass substrate as shown in Examples 1 to 6, the occurrence of cracks was significantly suppressed and holes having a desired depth could be formed. Was done.

100 Hole forming device 110 Laser oscillator 113 Laser beam 120 Beam expander 123 Laser beam 130 Wave plate 133 Laser beam 140 Aperture 143 Laser beam 150 Condensing lens 153 Focused laser beam 160 Stage 190 Glass substrate 192 First surface 194 Second Surface 196 Irradiation position 198 Through hole 212 Laser beam 214 Laser beam

Claims (16)

A method for manufacturing a glass substrate having holes having a depth of d (μm) or more.
It has a step of irradiating a glass substrate with a laser beam oscillated from a CO ₂ laser oscillator for an irradiation time of t (μsec) to form holes in the glass substrate.
The laser beam is focused by a condenser lens and then irradiated to the glass substrate.
When the power and beam cross-sectional area of the laser beam immediately before entering the condenser lens are P ₀ and S, respectively, the following equation (1)

P _d = P ₀ / S (1)

The power density P _d (W / cm ² ) represented by is 600 W / cm ² or less.
The irradiation time t (μsec) is

t ≧ 10 × d / (P _d ) ^1/2 Eq. (2)

Satisfy, manufacturing method. The manufacturing method according to claim 1, wherein the CO ₂ laser oscillator is a continuous wave CO ₂ laser oscillator. The manufacturing method according to claim 1, wherein the CO ₂ laser oscillator is a pulse CO ₂ laser oscillator. The manufacturing method according to claim 1, wherein the wavelength of the laser beam oscillated from the CO ₂ laser oscillator is in the range of 9.2 μm to 9.8 μm. The manufacturing method according to any one of claims 1 to 3, wherein the hole is a through hole. A method of forming holes with a depth of d (μm) or more on a glass substrate.
It has a step of irradiating a glass substrate with a laser beam oscillated from a CO ₂ laser oscillator for an irradiation time of t (μsec) to form holes in the glass substrate.
The laser beam is focused by a condenser lens and then irradiated to the glass substrate.
When the power and beam cross-sectional area of the laser beam immediately before entering the condenser lens are P ₀ and S, respectively, the following equation (1)

P _d = P ₀ / S (1)

The power density P _d (W / cm ² ) represented by is 600 W / cm ² or less.
The irradiation time t (μsec) is

t ≧ 10 × d / (P _d ) ^1/2 Eq. (2)

How to meet. The method according to claim 6, wherein the CO ₂ laser oscillator is a continuous wave CO ₂ laser oscillator. The method according to claim 6, wherein the CO ₂ laser oscillator is a pulse CO ₂ laser oscillator. The method according to any one of claims 6 to 8, wherein the hole is a through hole. A device that forms holes with a depth of d (μm) or more in a glass substrate.
A CO ₂ laser oscillator that oscillates a laser beam,
A condenser lens that concentrates the laser beam on a glass substrate,
Have,
By irradiating the glass substrate with the laser beam for an irradiation time t (μsec), holes are formed in the glass substrate.
When the power and beam cross-sectional area of the laser beam immediately before entering the condenser lens are P ₀ and S, respectively, the following equation (1)

P _d = P ₀ / S (1)

The power density P _d (W / cm ² ) represented by is 600 W / cm ² or less.
The irradiation time t (μsec) is

t ≧ 10 × d / (P _d ) ^1/2 Eq. (2)

Meet the device. The device according to claim 10, wherein the CO ₂ laser oscillator is a continuous wave CO ₂ laser oscillator. The device according to claim 10, wherein the CO ₂ laser oscillator is a pulse CO ₂ laser oscillator. The apparatus according to any one of claims 10 to 12, wherein the laser beam has a wavelength in the range of 9.2 μm to 9.8 μm. Further, between the CO ₂ laser oscillator and the condenser lens,
The apparatus according to any one of claims 10 to 13, further comprising an aperture for adjusting the beam cross-sectional area of the laser beam. The apparatus according to claim 14, further comprising a λ / 4 wave plate between the CO ₂ laser oscillator and the aperture. The device according to any one of claims 10 to 15, wherein the hole is a through hole.

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