JP2016049542A - Laser processing method, manufacturing method of glass processing part and laser processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser processing method which can form a fine and favorable hole, a manufacturing method of a glass processing part, and a laser processor.SOLUTION: A laser processing method has: a process for forming a modified part 50 by radiating an ultrashort pulse laser beam thereto while moving a focus point 56 of the ultrashort pulse laser beam A which progresses to a direction toward the other main surface from one main surface of a glass base board 46 to one main surface side from the other main surface side of the glass base board; and a process for opening a hole by etching the modified part. When setting the energy of the ultrashort pulse laser beam per one-pulse unit area as E, a moving speed of the focus point as v, and a repeating frequency as f, the following relationships are established. 0.05×10[J/m]≤E≤0.5×10[J/m]. 0.22×10[m.s]≤(v/f)≤10×10[m.s]. 0.018×10[J/(m.s)]≤(E.f/v)≤0.81×10[J/(m.s)].SELECTED DRAWING: Figure 3

Description

  The present invention relates to a laser processing method, a glass processing component manufacturing method, and a laser processing apparatus.

  As a technique for making a hole in an object, mechanical drilling using a drill or the like is known.

  However, in mechanical drilling, it is not easy to open a fine hole having a diameter of several μm to several tens of μm in a hard and brittle material.

  On the other hand, a technique for making a hole in an object by performing ablation using a laser beam has been proposed.

  However, when trying to form a hole by ablation using laser light, cracks are likely to occur, and the object may be broken.

  Recently, a technique has been proposed in which a modified portion is formed by irradiating glass or the like with laser light and a hole is formed by etching the modified portion (Patent Documents 1 and 2). If this technique is used, holes can be formed without causing cracks.

JP 2004-351494 A JP 2011-178642 A

  However, when a modified portion is formed simply by irradiating a laser beam, and this modified portion is etched, a good hole cannot always be formed.

  An object of the present invention is to provide a laser processing method, a glass processing component manufacturing method, and a laser processing apparatus that can satisfactorily form fine holes.

According to one aspect of the embodiment, the condensing point of the ultrashort pulse laser light traveling in the direction from one main surface of the glass substrate to the other main surface is determined from the other main surface side of the glass substrate. By irradiating the glass substrate with the ultrashort pulse laser light while moving to one main surface side, forming a modified portion on the glass substrate, and etching the modified portion, Forming a hole in a glass substrate, wherein E is energy per unit area of one pulse of the ultrashort pulse laser beam, v is a moving speed of the condensing point of the ultrashort pulse laser beam, and When the repetition frequency of the pulse laser beam is f, 0.05 × 10 ⁶ [J / m ² ] ≦ E ≦ 0.5 × 10 ⁶ [J / m ² ] and 0.22 × 10 ⁻¹² [m S] ≦ (v / f ² ) ≦ 10 × 10 ⁻¹² [M · s], 0.018 × 10 ¹⁸ [J / (m ³ · s)] ≦ (E · f ² /v)≦0.81×10 ¹⁸ [J / (m ³ · s)] A laser processing method is provided.

  According to another aspect of the embodiment, a step of stacking a plurality of plate-shaped bodies, and a pulse laser that travels in a direction from one main surface of the stacked body in which the plurality of plate-shaped bodies are stacked to the other main surface By irradiating the stacked body with the pulsed laser light while gradually moving a light condensing point from the other main surface side of the stack to the one main surface, There is provided a laser processing method including a step of forming a modified portion and a step of forming a hole in the plate-like body by etching the modified portion.

According to still another aspect of the embodiment, the condensing point of the ultrashort pulse laser light traveling in the direction from one main surface of the glass substrate toward the other main surface is set to the other main surface side of the glass substrate. Irradiating the glass substrate with the ultra-short pulse laser light while gradually moving from the main surface to the one main surface, and etching the modified portion. A step of opening a hole in the glass substrate, wherein E is the energy per unit area of one pulse of the ultrashort pulse laser beam, and v is the moving speed of the condensing point of the ultrashort pulse laser beam. If the repetition frequency of the ultrashort pulse laser beam is f, 0.05 × 10 ⁶ [J / m ² ] ≦ E ≦ 0.5 × 10 ⁶ [J / m ² ] and 0.22 × 10 ^{-12 [m · s] ≦ (} v / f 2) ≦ 10 10 ^-12 a [m · s], 0.018 × 10 18 [J / (m 3 · s)] ≦ (E · f 2 /v)≦0.81×10 18 [J / (m 3 · s)] is provided.

  According to still another aspect of the embodiment, a step of stacking a plurality of glass substrates, and a pulsed laser beam that travels in a direction from one main surface of the stack of the plurality of glass substrates to the other main surface The glass substrate is modified by irradiating the stack with the pulsed laser light while gradually moving the condensing point of the stack from the other main surface of the stack to the one main surface. There is provided a method for manufacturing a glass processed part, which includes a step of forming a portion and a step of forming a hole in the glass substrate by etching the modified portion.

According to still another aspect of the embodiment, a light source that emits ultrashort pulse laser light and a condensing point of the ultrashort pulse laser light traveling in a direction from one main surface of the glass substrate to the other main surface are provided. Control of forming a modified portion on the glass substrate by irradiating the glass substrate with the ultrashort pulse laser light while moving from the other main surface side of the glass substrate to the one main surface side. The energy per unit area of one pulse of the ultrashort pulse laser light, v the moving speed of the condensing point of the ultrashort pulse laser light, and the repetition frequency of the ultrashort pulse laser light If f is 0.05 × 10 ⁶ [J / m ² ] ≦ E ≦ 0.5 × 10 ⁶ [J / m ² ], 0.22 × 10 ⁻¹² [m · s] ≦ (v / F ² ) ≦ 10 × 10 ⁻¹² [m · s], 0.01 There is provided a laser processing apparatus that satisfies 8 × 10 ¹⁸ [J / (m ³ · s)] ≦ (E · f ² /v)≦0.81×10 ¹⁸ [J / (m ³ · s)]. .

  According to still another aspect of the embodiment, a light source that emits pulsed laser light and the pulsed laser light that travels in a direction from one main surface to the other main surface of a stacked body in which a plurality of plate-like bodies are stacked. The focusing point is irradiated with the pulse laser beam while gradually moving the condensing point from the other main surface side to the one main surface side of the stack. There is provided a laser processing apparatus having a control part for forming a mass part.

  According to the present invention, the modified portion is formed on the glass substrate by irradiating the ultrashort pulse laser light while moving the condensing point from the lower surface side to the upper surface side of the glass substrate. At this time, the energy E per unit area of one pulse of the ultrashort pulse laser beam, the moving speed v of the condensing point of the ultrashort pulse laser beam, and the repetition of the ultrashort pulse laser beam so as to satisfy the predetermined formula Set the frequency f. For this reason, according to this invention, a moderate modification part can be formed in a glass substrate. If the modified portion is etched, fine holes can be formed satisfactorily.

  Moreover, according to this invention, a modification part is formed by irradiating a laser beam in the state which accumulated the some plate-shaped object. In a plate-like body whose upper and lower sides are sandwiched between other plate-like bodies, laser light is irradiated in a state where the surface layer portion is not exposed in the air. For this reason, it is possible to prevent the processing threshold from being extremely lowered in a plate-like body whose upper and lower sides are sandwiched between other plate-like bodies. For this reason, according to the present invention, in the plate-like body whose upper and lower sides are sandwiched by other plate-like bodies, it is possible to form a good modified portion, and consequently, the upper and lower sides are sandwiched by other plate-like bodies. Good holes can be formed in the plate-like body.

It is a block diagram which shows the laser processing apparatus by 1st Embodiment of this invention. It is a time chart which shows notionally the waveform of the laser beam emitted from a laser light source. It is process sectional drawing which shows the laser processing method and manufacturing method of glass processing components by 1st Embodiment of this invention. It is process sectional drawing which shows the laser processing method and manufacturing method of glass processing components by 1st Embodiment of this invention. FIG. 5A is a table showing the relationship between the feed speed of the laser beam condensing point, the repetition frequency of the laser light, and the determination result of the quality of the formed hole, and FIG. It is a table | surface which shows the product Y of the spatial irradiation interval D of the laser beam in the feed direction of a point, and the temporal irradiation interval T of the laser beam. It is a figure which shows the SEM image of the hole formed in the glass substrate. It is a figure which shows the SEM image of the hole formed in the glass substrate. It is a table | surface which shows the relationship between the mixing amount of the 1st chemical | medical solution in a etching liquid, and the 2nd chemical | medical solution, and the taper angle of the formed hole. It is a figure which shows the optical microscope photograph of the hole formed in the glass substrate. It is a figure which shows the optical microscope photograph of the hole formed in the glass substrate. It is a block diagram which shows the laser processing apparatus by 2nd Embodiment of this invention. It is process sectional drawing which shows the laser processing method by 2nd Embodiment of this invention, and the manufacturing method of glass processing components. It is process sectional drawing which shows the laser processing method by 2nd Embodiment of this invention, and the manufacturing method of glass processing components. It is a figure which shows the SEM image which observed the hole formed in the glass substrate from the upper surface side of the glass substrate.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment, In the range which does not deviate from the summary, it can change suitably. In the drawings described below, components having the same function are denoted by the same reference numerals, and the description thereof may be omitted or simplified.

[First Embodiment]
A laser processing method, a glass processing component manufacturing method, and a laser processing apparatus according to a first embodiment of the present invention will be described with reference to the drawings.

(Laser processing equipment)
First, the laser processing apparatus used in the laser processing method and the crow processing part manufacturing method according to the present embodiment will be described. FIG. 1 is a block diagram showing the laser processing apparatus according to the present embodiment. In FIG. 1, the connection between each component is shown with the continuous line, and the optical path of a laser beam is shown with the broken line.

  The laser processing apparatus 2 according to the present embodiment forms a modified portion (deformed portion) 50 (see FIG. 3) in the workpiece 16 by irradiating the workpiece 16 with laser light. Since the modified portion 50 is easily etched, holes (through holes) 52 (see FIG. 4B) can be formed by etching the modified portion 50. Then, if a conductor is embedded in the hole 52, a through electrode (via) 54 can be formed in the hole 52.

  The laser processing apparatus 2 according to the present embodiment includes a laser light source 10 that emits laser light A and a control unit 14 that controls the entire laser processing apparatus according to the present embodiment. The laser processing apparatus 2 according to the present embodiment further includes a stage 18 on which the processing object 16 is placed.

  The laser processing apparatus 2 according to the present embodiment is provided in a manufacturing apparatus that manufactures glass processing parts, for example. Here, the case where the processing target 16 is the glass substrate 46 will be described as an example, but the processing target 16 is not limited to the glass substrate 46. The laser processing apparatus 2 according to the present embodiment can form the modified portion 50 on various workpieces 16 and can manufacture various articles.

  The control unit 14 has a CPU (not shown) that executes processing such as various calculations, control, and determination. The control unit 14 includes a ROM (not shown) that stores various control programs executed by the CPU. The control unit 14 includes a RAM (not shown) that temporarily stores data being processed by the CPU, input data, and the like.

  The control unit 14 is connected to an input operation unit 38 for a user to input predetermined commands and data. For example, a keyboard and various switches are used as the input operation unit 38.

  A display unit 40 for performing various displays is connected to the control unit 14. On the display unit 40, for example, the operating state of the laser processing apparatus 2 according to the present embodiment, the state of the stage 18, the image acquired by the CCD camera 42, and the like are displayed. For example, a liquid crystal display or the like is used as the display unit 40.

The laser light source 10 emits laser light (laser beam) A. More specifically, the laser light source 10 emits pulsed laser light A. Here, as the pulse laser beam A, for example, an ultrashort pulse laser is used. For example, femtosecond laser light is used as the ultrashort pulse laser light A. The femtosecond laser beam is generally a laser beam having a pulse width of the order of femtosecond (fs: ^10-15 seconds), that is, a laser beam having a pulse width of 1 fs or more and less than 1 ps. From the laser light source 10, for example, a pulse laser beam A having a pulse width on the order of femtoseconds is emitted. In the present embodiment, for example, a laser oscillator having a center wavelength of about 1045 nm and a pulse width of about 800 fs is used as the laser light source 10. The reason why the ultrashort pulse laser beam is used as the pulse laser beam A in the present embodiment is that the ultrashort pulse laser beam can realize precise fine processing without causing thermal melting.

  Although the case where the pulse width of the laser beam A is set to about 800 fs is described as an example here, the pulse width of the laser beam A is not limited to about 800 fs. Further, the pulse width of the laser light A is not limited to the femtosecond order, but may be the picosecond order. In the specification and claims of the present application, ultrashort pulse laser light is not limited to pulse laser light having a pulse width of femtoseconds, but a picosecond laser having a pulse width of several tens of picoseconds or less. Including light. In the specification and claims of the present application, femtosecond laser light is not limited to laser light having a pulse width of femtoseconds, but a picosecond laser having a pulse width of several tens of picoseconds or less. Including light.

  Further, the center wavelength of the laser light A emitted from the laser light source 10 is not limited to about 1045 nm, and can be set as appropriate.

  The rated output of the laser light source 10 that emits the laser light A is about 120 mW, for example. The rated output of the laser light source 10 that emits the laser light A is not limited to about 120 mW, and can be set as appropriate.

  The laser light source 10 is controlled by the control unit 14. The controller 14 emits the pulsed laser light A from the laser light source 10 with a preset pulse width and repetition frequency. The pulse width, repetition frequency, and the like of the laser light A emitted from the laser light source 10 can be appropriately set by the user via the input operation unit 38. FIG. 2 is a time chart conceptually showing the waveform of the laser light emitted from the laser light source. As shown in FIG. 2, a pulse of the laser beam A is emitted at a predetermined repetition period T. The repetition frequency of the laser light pulse is, for example, about 1 kHz to 1 MHz. In addition, the repetition frequency of the pulse of the laser beam A is not limited to about 1 kHz to 1 MHz, and can be set as appropriate. Various setting information input by the user is appropriately stored in a storage unit (not shown) provided in the control unit 14.

  A beam expander 12 for adjusting the beam diameter of the laser light A is provided at the subsequent stage of the laser light source 10 that emits the laser light A. A half-wave plate 20 that controls the polarization direction of the laser light is provided at the subsequent stage of the beam expander 12. A polarizing beam splitter 22 that adjusts the output of the laser light is provided at the subsequent stage of the half-wave plate 20. The half-wave plate 20 is an optical element that can change the polarization direction of the laser light by rotating. The polarization beam splitter 22 is an optical element that can branch the polarization component of incident light. When the polarization direction of the laser light is changed by rotating the half-wave plate 20, the ratio of the polarization component branched in the polarization beam splitter 22 changes. By appropriately adjusting the rotation angle of the half-wave plate 20, the power of the laser light emitted from the polarization beam splitter 22 can be adjusted as appropriate. The half-wave plate 20 and the polarization beam splitter 22 are combined to form an output attenuator 24. As described above, the laser intensity of the pulsed laser light emitted from the laser light source 10 can be adjusted by the output attenuator 24. The user can set the laser intensity (pulse energy) of the pulsed laser light applied to the workpiece 16 through the input operation unit 38 as appropriate.

  It is preferable that the pulse energy of the laser beam A adjusted by the output attenuator 24, that is, the pulse energy of the laser beam A irradiated to the workpiece 16 is set appropriately. More specifically, it is preferable to set the pulse energy per unit area of the laser beam A irradiated to the workpiece 16 appropriately. This is because when the pulse energy per unit area of the laser beam A irradiated to the workpiece 16 (energy per unit area of one pulse) is excessively high, fine and good holes 52 cannot be formed. . On the other hand, when the pulse energy per unit area of the laser beam A irradiated to the workpiece 16 is excessively low, the modification cannot be performed sufficiently, which causes a defective opening.

  Here, the case where the intensity of the laser beam is adjusted using the output attenuator 24 constituted by the half-wave plate 20 and the polarization beam splitter 22 has been described as an example, but the intensity of the laser beam A is adjusted. The means to do is not limited to this. The intensity of the laser beam A can be adjusted as appropriate using any adjusting means.

  A beam expander 26 for adjusting the beam diameter of the laser light A is provided at the subsequent stage of the output attenuator 24. A mirror 30 is disposed downstream of the beam expander 26. The laser beam A introduced into the mirror 30 is reflected by the mirror 30 and introduced into the lens (objective lens) 32. The magnification of the lens 32 is about 20 times, for example. The numerical aperture (NA) of the lens 32 is about 0.4, for example. The beam diameter at the condensing point (focal point, beam waist) 55 (see FIG. 3) of the laser beam A is, for example, about φ2.6 μm. The beam diameter is obtained by dividing the wavelength by the numerical aperture (NA). Further, the beam diameter of the laser beam A at the condensing point 55 is not limited to about φ2.6 μm and can be set as appropriate.

  The stage 18 is located below the lens 32. A workpiece 16 is placed on the stage 18. The workpiece (workpiece, object, article) 16 is, for example, a glass substrate 46. The glass substrate 46 is, for example, a multicomponent glass substrate (multicomponent glass substrate). More specifically, the glass substrate 46 is made of alkali-free glass. The glass substrate 46 is not limited to a multi-component glass substrate. Various glass substrates 46 can be used as the workpiece 16. The processing object 16 is not limited to the glass substrate, and various objects can be used as the processing object.

  The traveling direction of the laser beam A irradiated to the workpiece 16 is a direction from the one main surface (upper surface in FIG. 1) side of the workpiece 16 toward the other main surface (lower surface in FIG. 1).

  A stage driving unit 36 for driving the stage 18 is connected to the stage 18. The control unit 14 drives the stage 18 via the stage driving unit 36. As the stage 18, for example, an XYZθ axis stage can be used. For example, the control unit 14 can move the stage 18 up and down at a desired speed in the normal direction of the upper surface of the stage 18. Since the stage 18 can be moved up and down at a desired speed, the condensing point (focal point, beam waist) 56 (see FIG. 3) of the laser light A can be moved in the vertical direction at a desired feed speed. The feed speed of the condensing point 56 of the laser light A is the moving speed of the condensing point 56 of the laser light A when the condensing point 56 is moved along the optical axis of the laser light A. The direction in which the condensing point 56 of the laser beam A is sent is the direction from the other main surface (lower surface in FIG. 1) side of the workpiece 16 toward the one main surface (upper surface in FIG. 1) side of the workpiece 16. To do. The feed direction of the condensing point 56 of the laser beam A is the moving direction of the condensing point 56 of the laser beam A when the condensing point 56 is moved along the optical axis of the laser beam A.

  The stage 18 is not limited to the XYZθ axis stage, and may be, for example, an XYZ axis stage.

  The beam diameter of the laser beam A at the condensing point 56 is appropriately set within a range of several μm to several tens of μm, for example. The beam diameter of the laser beam A at the condensing point 56 is not limited to several μm to several tens of μm, and can be set as appropriate.

  The cross-sectional shape of the laser beam A at the condensing point 56 is, for example, a circle. Note that the cross-sectional shape of the laser beam A at the condensing point 56 is not limited to a circle, and may be, for example, an ellipse.

  A CCD camera 42 is provided above the stage 18. An image acquired by the CCD camera 42 is input to the control unit 14. The control unit 14 uses the image acquired by the CCD camera 42 to position the processing target 16.

  Before the scanning of the laser beam A with respect to the workpiece 16 is started, the position of the workpiece 16 is set to a predetermined position. The control unit 14 appropriately controls the stage 18 via the stage control unit 36 and positions the workpiece 16 within a range where the laser beam A can be irradiated.

  When starting irradiation of the laser beam A onto the workpiece 16, for example, the user gives an instruction to start irradiation of the laser beam A via the input operation unit 38.

  When an instruction to start irradiation with the laser beam A is input, the control unit 14 moves the stage 18 in the XY direction (on the upper surface of the stage 18 so that the laser beam A is irradiated onto a predetermined portion of the workpiece 16. (In-plane direction). Then, the control unit 14 moves the stage 18 in the Z direction (the normal direction of the upper surface of the stage 18), thereby moving the condensing point 56 of the laser beam A at a desired feed speed, while processing the workpiece 16. Is irradiated with laser light A. Instead of moving the stage 18 in the Z direction, the condensing point 56 may be moved by moving the lens 32 in the Z direction.

  Irradiation with the laser beam A is sequentially performed on each irradiation target portion. When the irradiation with the laser beam A is completed for all the planned irradiation locations, the step of irradiating the laser beam A is completed.

(Laser processing method and glass processing part manufacturing method)
Next, the laser processing method and the glass processing part manufacturing method according to the present embodiment will be described with reference to the drawings. 3 and 4 are process cross-sectional views illustrating the laser processing method and the glass processing component manufacturing method according to the present embodiment.

  The laser processing method and the glass processing component manufacturing method according to the present embodiment can be implemented using, for example, the laser processing apparatus according to the present embodiment described above with reference to FIG.

  First, the workpiece 16 is prepared. The workpiece 16 is a glass substrate 46, for example. As the glass substrate 46, for example, a multi-component glass substrate is used. The thickness of the glass substrate 46 is about 100 μm, for example. The glass substrate 46 is not limited to a multi-component glass substrate, and various glass substrates 46 can be used as appropriate. Further, the processing object 16 is not limited to the glass substrate 46, and various objects can be used as the processing object 16.

  Next, the irradiation of the laser beam A to the irradiation scheduled part is started. FIG. 3A shows a stage where the irradiation of the laser beam A is started on the planned irradiation position. The traveling direction of the laser beam A is a direction from one main surface (upper surface in FIG. 3A) side of the workpiece 16 toward the other main surface (lower surface in FIG. 3A). The position of the condensing point 56 of the laser beam A at the stage of starting the irradiation with the laser beam A is set near the lower surface of the workpiece 16. As the laser beam A, for example, an ultrashort pulse laser beam is used. The ultra-short pulse laser beam is used as the laser beam A. When the ultra-short pulse laser beam is used, the fine and good modified portion 50 can be formed, and consequently the fine and good hole 52 is formed. This is because it is possible. Here, for example, femtosecond laser light having a pulse width of about 800 fs is used as the laser light A. Note that the pulse width of the ultrashort laser beam A is not limited to 800 fs, and can be set as appropriate. The wavelength of the laser beam A is about 1045 nm, for example. Note that the wavelength of the laser light is not limited to 1045 nm, and can be set as appropriate.

  The diameter of the cross section of the laser beam A at the condensing point 56 is, for example, about φ2.6 μm. The diameter of the cross section of the laser beam A at the condensing point 56 is not limited to about φ2.6 μm, and may be set as appropriate according to the diameter of the hole 52 to be formed.

  When the energy per unit area (pulse energy per unit area) of one pulse of the laser beam A irradiated to the workpiece 16 is E, it is preferable that E satisfies the following formula (1).

0.05 × 10 ⁶ [J / m ² ] ≦ E ≦ 0.5 × 10 ⁶ [J / m ² ] (1)

  The reason why the pulse energy E per unit area of the laser light A irradiated to the workpiece 16 is set within the range shown in the equation (1) is as follows. That is, when the pulse energy E per unit area of the laser beam A irradiated to the workpiece 16 is relatively small, sufficient modification cannot be performed, which causes a defective opening. On the other hand, when the pulse energy E per unit area of the laser beam A irradiated to the workpiece 16 is relatively large, excessive modification occurs, and the good hole 52 cannot be formed. In order to form a good hole 52, it is preferable to appropriately set the pulse energy E per unit area of the laser light A irradiated to the workpiece 16, and set it within the range of the formula (1). Very important. For this reason, in this embodiment, the pulse energy E per unit area of the laser light irradiated onto the workpiece 16 is set so as to satisfy the formula (1).

  The converging point 56 of the laser beam A is sent in the direction from the other main surface (the lower surface in FIG. 3A) side of the workpiece 16 toward the one main surface (the upper surface in FIG. 3A). And The reason why the converging point 56 of the laser beam A is sent from the lower surface side to the upper surface side of the workpiece 16 is as follows. That is, when the workpiece 16 is irradiated with the laser beam A, the modification occurs in the vicinity of the condensing point 56. The laser beam A is difficult to reach below the modified portion. Therefore, when the feeding direction of the condensing point 56 of the laser beam A is a direction from the upper surface side to the lower surface side of the workpiece 16, the laser beam is hindered by the modified portion formed on the upper surface side, It becomes difficult to make the laser beam reach the lower surface side. For this reason, the feeding direction of the condensing point 56 of the laser light A is the direction from the lower surface side to the upper surface side of the workpiece 16.

  The feeding speed of the condensing point 56 of the laser beam A is preferably in the range of 1 mm / s to 20 mm / s. The reason why the feeding speed of the condensing point 56 of the laser beam A is preferably in the range of 1 mm / s to 20 mm / s is as follows. That is, when the feeding speed of the condensing point 56 of the laser beam A is relatively slow, excessive modification may occur and the good hole 52 may not be formed. Further, when the feeding speed of the laser beam A at the condensing point 56 is relatively slow, the throughput is also lowered. On the other hand, when the feeding speed of the condensing point 56 of the laser beam A is relatively high, sufficient modification cannot be performed, which causes a defective opening or the like. Therefore, in order to form a good hole 52 with high throughput, it is preferable to set the feed speed of the condensing point 56 of the laser light A within the range of 1 mm / s to 20 mm / s.

  The feeding speed of the condensing point 56 of the laser beam A is not limited to 1 mm / s to 20 mm / s, and can be set as appropriate.

  It is preferable that the spatial irradiation interval D of the laser beam A in the direction in which the condensing point 56 of the laser beam A is sent is set appropriately. The reason why the spatial irradiation interval D of the laser beam A in the feeding direction of the condensing point 56 of the laser beam A is preferably set appropriately is as follows. That is, when the spatial irradiation interval D of the laser light A in the feeding direction of the condensing point 56 is relatively small, the portions where the laser light A is condensed overlap each other, resulting in excessive modification and good The hole 52 may not be formed. Further, when the spatial irradiation interval D of the laser beam A in the feeding direction of the condensing point 56 is relatively large, sufficient modification cannot be performed, which causes a defective opening or the like. The spatial irradiation interval of the laser beam A in the feeding direction of the condensing point 56 is defined by the feed speed v of the condensing point 56 of the laser beam A and the repetition frequency f of the laser beam A. Therefore, the feed speed v of the condensing point 56 of the laser light A and the repetition frequency f of the laser light A are set so that the spatial irradiation interval D of the laser light A in the feed direction of the condensing point 56 becomes an appropriate size. Is preferably set as appropriate.

FIG. 5A is a table showing the relationship between the laser beam condensing point feed speed v, the laser beam repetition frequency f, and the quality of the hole 52 formed. The horizontal axis in FIG. 5A indicates the feed speed v of the condensing point 56 of the laser beam A, and the vertical axis in FIG. 5A indicates the repetition frequency f of the laser beam A. The circles in FIG. 5A indicate that the holes 52 formed under the conditions were good. The crosses in FIG. 5 (a) indicate that the holes 52 formed under the conditions were not good. The Δ mark in FIG. 5A indicates that the hole 52 formed under the condition is not always satisfactory. In FIG. 5A, the case where the good hole 52 is formed, that is, the case where it is ◯, is highlighted by being surrounded by a thick line. A blank in FIG. 5A indicates that the experiment was not performed under the conditions. In the experiment, the center wavelength λ of the laser beam A was set to 1045 μm. The numerical aperture NA of the lens 32 is about 0.4. Further, the diameter of the laser beam A at the condensing point 56 was about 2.6 μm. The cross-sectional area of the laser beam A at the condensing point 56 was set to about 5.3 μm ² . In addition, the pulse energy E per unit area of the laser beam A irradiated to the workpiece 16 is about 0.18 × 10 ⁶ [J / m ² ].

FIG. 5B is a table showing the product Y of the spatial irradiation interval D of the laser beam and the temporal irradiation interval T of the laser beam in the feed direction of the condensing point. The horizontal axis in FIG. 5B indicates the feed speed v of the condensing point 56 of the laser light A, and the vertical axis in FIG. 5B indicates the repetition frequency f of the laser light A. The unit of the product Y shown in FIG. 5B is 10 ⁻¹² [m · s].

  Assuming that the spatial irradiation interval of the laser beam A in the feeding direction of the focusing point 56 is D, the feeding speed of the focusing point 56 of the laser beam A is v, and the repetition frequency of the laser beam A is f, Equation (2) is established.

  D = v / f (2)

  Further, when the temporal irradiation interval of the laser beam A is T, the following formula (3) is established.

  T = 1 / f (3)

  When the product of the spatial irradiation interval D of the laser beam A and the temporal irradiation interval T of the laser beam A in the feeding direction of the condensing point 56 is Y, the following equation (4) is established.

Y = D · T = (v / f) · (1 / f) = v / f ² (4)

  FIG. 5B shows the product Y of the spatial irradiation interval D of the laser beam A and the temporal irradiation interval T of the laser beam A in the feeding direction of the condensing point 56 as described above. The value calculated by the equation (4) is described.

As can be seen by comparing FIG. 5A and FIG. 5B, the spatial irradiation interval D of the laser light A and the temporal irradiation interval T of the laser light A in the feed direction of the condensing point 56 Is related to the quality of the hole 52 to be formed. When the product Y of the spatial irradiation interval D of the laser beam A and the temporal irradiation interval T of the laser beam A in the feeding direction of the condensing point 56 is too large, the favorable hole 52 cannot be formed. On the other hand, even when the product Y of the spatial irradiation interval D of the laser beam A and the temporal irradiation interval T of the laser beam A in the feeding direction of the condensing point 56 is too small, a good hole 52 can be formed. Absent. As can be seen by comparing FIG. 5A and FIG. 5B, in order to form a good hole 52, the spatial irradiation interval D of the laser light A in the feed direction of the condensing point 56 is The product Y with the temporal irradiation interval T of the laser beam A, that is, the value of v / f ² needs to satisfy the following formula (5).

0.2222 × 10 ⁻¹² [m · s] ≦ v / f ² ≦ 10 × 10 ⁻¹² [m · s] (5)

As described above, when the modified portion 50 is formed, the pulse energy E per unit area of the laser beam A irradiated to the workpiece 16 is 0.18 × 10 ⁶ [J / m ² ]. did.

  Therefore, the following formula (6) can be obtained based on the pulse energy E per unit area of the laser beam A and the formula (5) when the modified portion 50 is formed. Equation (6) shows the range of the ratio of the pulse energy E per unit area of the laser beam to the product Y of the spatial irradiation interval D of the laser beam and the temporal irradiation interval T of the laser beam.

{(0.18 × 10 ⁶ [J / m ² ]) / (10 × 10 ⁻¹² [m · s])} ≦ (E / Y) ≦ {(0.18 × 10 ⁶ [J / m ² ] ) / (0.2222 × 10 ⁻¹² [m · s])} (6)

  Summarizing the equation (6), the following equation (7) is obtained.

0.018 × 10 ¹⁸ [J / (m ³ · s)] ≦ (E · f ² /v)≦0.81×10 ¹⁸ [J / (m ³ · s)] (7)

Thus, the pulse energy E per unit area of the laser beam A, the repetition frequency f of the laser beam A, and the feed of the laser beam A so as to satisfy the equations (1), (5), and (7) If the speed v is set, a good hole 52 can be formed. Therefore, the pulse energy E per unit area of the laser light A, the repetition frequency f of the laser light, and the feed speed v of the laser light are set so as to satisfy the expressions (1), (5), and (7). To do. Here, the pulse energy E per unit area of the laser light A is, for example, about 0.18 × 10 ⁶ [J / m ² ]. Here, the repetition frequency f of the laser light A is set to about 100 kHz, for example. Further, here, the feed speed v of the condensing point 56 of the laser light A is, for example, about 20 mm / s. Note that the pulse energy E per unit area of the laser light A, the repetition frequency f of the laser light A, and the feed speed v of the laser light A are not limited to these, and the expressions (1), (5), and What is necessary is just to set suitably in the range with which Formula (7) is satisfy | filled.

  FIG. 3B is a cross-sectional view showing a state in which the condensing point 56 of the laser beam A is moved halfway. As can be seen from FIG. 3B, the modified portion 65 is formed up to the position where the condensing point 56 of the laser beam A is moved.

  FIG. 3C is a cross-sectional view showing a state in which the condensing point 56 of the laser light A is moved to the upper surface of the workpiece 16. As can be seen from FIG. 3C, the modified portion 50 is formed up to the upper surface of the workpiece 16.

  FIG. 4A shows a state in which the irradiation of the laser beam A to all the irradiation scheduled locations is completed. When the irradiation of the laser beam A is completed for all the planned irradiation positions, the workpiece 16 is removed from the stage 18.

Next, the workpiece 16 is etched. As the etching method, for example, wet etching is used. As described above, a multi-component glass substrate is used here as the glass substrate 46 that is the workpiece 16. The multi-component glass substrate includes, for example, at least a silicon oxide that is a first component and a second component that is a component different from the first component. Hydrofluoric acid tends to react with silicon oxide, and particularly reacts with modified silicon oxide, but does not react very much with the second component. For this reason, when it is going to etch the modification part 50 using only hydrofluoric acid, a long time will be required for etching. Therefore, in the present embodiment, as the etching solution, hydrofluoric acid (HF) that is a first chemical solution that reacts with silicon oxide that is the first component, and a second chemical solution that is an acidic chemical solution that reacts with the second component. An etching solution containing a chemical solution is used. For example, nitric acid (NHO ₃ ), hydrochloric acid (HCl), phosphoric acid (H ₃ PO ₄ ), or sulfuric acid (H ₂ SO ₄ ) can be used as the second chemical solution. Here, for example, nitric acid is used as the second chemical solution. Since etching is performed using such an etchant, the modified portion 52 can be etched at a sufficiently fast etching rate.

  When the ratio of the mixing amount of the second chemical solution to the mixing amount of the first chemical solution in the etching solution is increased, the taper angle of the hole 52 formed in the glass substrate 46 tends to increase. The reason why the taper angle of the hole 52 increases when the ratio of the mixing amount of the second chemical solution to the mixing amount of the first chemical solution in the etching solution is increased is as follows. That is, the first chemical solution has a very high selectivity for the modified silicon oxide. On the other hand, the second chemical solution is not so selective with respect to the modified silicon oxide. For this reason, if the ratio of the mixing amount of the second chemical liquid to the mixing amount of the first chemical liquid in the etching liquid is increased, the etching anisotropy is weakened. For this reason, if the ratio of the mixing amount of the second chemical solution to the mixing amount of the first chemical solution in the etching solution is increased, the taper angle of the hole 52 is increased.

  Note that the taper angle of the hole 52 formed in the glass substrate 46 tends to increase when the ratio of the mixing amount of the second chemical solution to the mixing amount of the first chemical solution in the etching solution is increased. This is a phenomenon that the inventors have found for the first time.

  If the mixing ratio of hydrofluoric acid as the first chemical liquid and nitric acid as the second chemical liquid is, for example, 1: 1, the hole 52 having a small taper angle can be formed. Here, the mixing ratio of hydrofluoric acid as the first chemical liquid and nitric acid as the second chemical liquid is, for example, 1: 1.

  The etching time can be about 5 to 10 minutes, for example. The etching time is not limited to about 5 to 10 minutes, and may be set as appropriate according to the thickness of the glass substrate 46 that is the workpiece 16.

  During the etching, the etching solution may be stirred or the etching solution may not be stirred. Here, the etching solution is not stirred.

  The temperature of the etching solution is, for example, room temperature. Note that the temperature of the etching solution is not limited to room temperature, and can be set as appropriate.

  Since the etching rate of the modified layer 50 is sufficiently faster than the etching rate of the unmodified portion of the glass substrate 46, when etching is performed, holes (through-holes) are formed in the glass substrate 46 that is the workpiece 16. ) 52 is formed. The diameter of the hole 52 is, for example, about φ15 μm. The diameter of the hole 52 is not limited to about φ15 μm, and can be set as appropriate.

  Next, as shown in FIG. 4C, a via (conductor) 54 is embedded in the hole 52. For example, copper (Cu) is used as the material of the via 54. For example, the via 54 can be embedded in the hole 52 by using an electroless plating method and an electroplating method.

  Thus, a glass processed part in which the via 54 is embedded in the hole 52 is obtained. Examples of the glass processed part that can be manufactured in this manner include a glass interposer. In addition, the glass processed part manufactured in this way is not limited to a glass interposer.

(Evaluation results)
Next, evaluation results of the laser processing method and the glass processing component manufacturing method according to the present embodiment will be described with reference to the drawings.

FIG. 6A is a view showing an SEM (Scanning Electron Microscope) image in which holes formed in the glass substrate by the laser processing method according to the present embodiment are observed from the upper surface side of the glass substrate. FIG. 6B is a view showing an SEM image of a cross section of the hole 52 formed in the glass substrate by the laser processing method according to the present embodiment. FIG. 6B is an observation of a cross section along the longitudinal direction of the hole 52. When the hole 52 shown in FIG. 6 is formed, the pulse energy E per unit area of the laser beam A and the repetition of the laser beam are satisfied so as to satisfy the above-described formulas (1), (5), and (7). The frequency f and the laser beam feed speed v were set. Specifically, when the hole 52 shown in FIG. 6 is formed, the pulse energy E per unit area of the laser beam A is set to 0.18 × 10 ¹⁶ [J / m ² ], and the laser beam A is condensed. The feed speed v at point 56 was 20 mm / s, and the repetition frequency f of the laser beam A was 100 kHz. The mixing amount of hydrofluoric acid in the etching solution was 1 mol / kg, and the mixing amount of nitric acid in the etching solution was 1 mol / kg. The etching time was 5 minutes.

  As can be seen from FIG. 6, fine and good holes 52 could be formed in the glass substrate 46. The diameter of the hole 52 was about φ15 μm.

FIG. 7 is an electron micrograph of a cross section in the longitudinal direction of the hole. FIG. 7A shows the case of the first embodiment. In Example 1, the pulse energy E per unit area of the laser light A, the repetition frequency f of the laser light, and the laser light so as to satisfy the above-described expressions (1), (5), and (7) The feed speed v was set. Specifically, in Example 1, the pulse energy E per unit area of the laser beam A is 0.18 × 10 ¹⁶ [J / m ² ], and the feed speed v of the condensing point 56 of the laser beam A is 20 mm. / S, and the repetition frequency f of the laser beam A was 100 kHz. FIG. 7B shows the case of Comparative Example 2. In Comparative Example 2, the spatial irradiation interval D of the laser beam A was set to be small. Specifically, in Comparative Example 2, the pulse energy E per unit area of the laser beam A is 0.18 × 10 ¹⁶ [J / m ² ], and the feed speed v of the condensing point 56 of the laser beam A is 20 mm. / S, and the repetition frequency f of the laser beam A was 400 kHz. In Comparative Example 2, the value of v / f ² was 12.5 × 10 ⁻¹² [m · s] and did not satisfy the formula (5).

  As can be seen from FIG. 7B, in the case of Comparative Example 2, large irregularities were generated on the inner wall of the hole 152. In Comparative Example 2, the large unevenness on the inner wall of the hole 152 is considered to be due to the excessive modification due to the overlapping of the portions where the laser light A is collected.

  On the other hand, as can be seen from FIG. 7A, in the case of Example 1, that is, in the case of the present embodiment, large irregularities were not confirmed on the inner wall of the hole 52. Thus, according to this embodiment, it is possible to form fine and good holes 52.

  FIG. 8 is a table showing the relationship between the mixing amount of the first chemical solution and the second chemical solution in the etching solution and the taper angle of the hole formed in the glass substrate. As the first chemical solution, hydrofluoric acid was used. Nitric acid was used as the second chemical solution. Comparative Example 1 shows a case where the mixed amount of hydrofluoric acid is 1 mol / kg and the mixed amount of nitric acid is 0 mol / kg. Example 2 shows a case where the amount of hydrofluoric acid is 1 mol / kg and the amount of nitric acid is 1 mol / kg. Example 3 shows a case where the amount of hydrofluoric acid is 1 mol / kg and the amount of nitric acid is 3 mol / kg. In Example 4, the amount of hydrofluoric acid mixed was 1 mol / kg, and the amount of nitric acid mixed was 5 mol / kg. In Example 5, the amount of hydrofluoric acid mixed was 1 mol / kg, and the amount of nitric acid mixed was 7 mol / kg.

  9 and 10 are diagrams showing optical micrographs of the holes formed in the glass substrate. 9A corresponds to Comparative Example 1, FIG. 9B corresponds to Example 2, and FIG. 9C corresponds to Example 3. FIG. 10A corresponds to the fourth embodiment, and FIG. 10B corresponds to the fifth embodiment.

  As can be seen from FIGS. 8 to 10, when the ratio of the mixing amount of the second chemical solution to the mixing amount of the first chemical solution in the etching solution increases, the taper angle of the hole 52 to be formed increases. Therefore, the ratio between the mixing amount of the first chemical solution and the mixing amount of the second chemical solution in the etching solution may be set so that a desired taper angle is obtained. A desired taper angle can be obtained by appropriately setting the ratio of the mixing amount of the second chemical solution to the mixing amount of the first chemical solution.

  Thus, according to the present embodiment, the modified portion 50 is applied to the glass substrate 46 by irradiating the ultrashort pulse laser beam A while moving the condensing point 56 from the lower surface side to the upper surface side of the glass substrate 46. Form. At this time, the energy E per unit area of the ultrashort pulse laser beam A and the condensing of the ultrashort pulse laser beam A so as to satisfy the above formulas (1), (5), and (7). The moving speed v of the point 56 and the repetition frequency f of the ultrashort pulse laser beam A are set. For this reason, according to the present embodiment, an appropriate modified portion 50 can be formed on the glass substrate 46. And if the modification part 50 is etched, the fine and favorable hole 52 can be formed.

  Moreover, according to this embodiment, the acidic chemical | medical solution which not only contains the hydrofluoric acid which is the 1st chemical | medical solution which reacts with the 1st component contained in a glass substrate but reacts with the 2nd component contained in a glass substrate. The modified portion 50 is etched using an etching solution that also contains the second chemical solution. For this reason, according to this embodiment, even when the glass substrate is multi-component glass, the modified portion 50 can be etched in a very short time. In addition, the taper angle of the hole 52 can be set to a desired angle by appropriately setting the mixing ratio of the first chemical liquid and the second chemical liquid in the etching liquid.

[Second Embodiment]
A laser processing method, a glass processing component manufacturing method, and a laser processing apparatus according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 11 is a block diagram showing the laser apparatus according to the present embodiment. 12 and 13 are process cross-sectional views illustrating the laser processing method and the glass processing component manufacturing method according to the present embodiment. The same components as those in the laser processing method according to the first embodiment shown in FIGS. 1 to 10 are denoted by the same reference numerals, and description thereof is omitted or simplified.

  The laser processing method and the glass processing component manufacturing method according to the present embodiment irradiate the laser beam A with a plurality of plate-like bodies 46a to 46e being stacked.

  As the laser processing method and the glass processing component manufacturing method according to the present embodiment, for example, a laser processing apparatus similar to the laser processing apparatus according to the first embodiment described above with reference to FIG. 1 can be used.

  First, as shown in FIG. 11, the workpiece 16 is placed on the stage 18. The workpiece 16 is, for example, a stacked body 48 in which a plurality of plate-like bodies 46a to 46e are stacked. In this embodiment, the laser beam A is irradiated in a state where the plurality of plate-like bodies 46a to 46e are stacked. The laser beam A is emitted in a state where other plate-like bodies exist above and below a certain plate-like body. Then, it is because the favorable modified part 50 can be formed in the said plate-shaped object. Since there is no other plate-like body below the lowermost plate-like body 46a, a good modified portion 50 cannot always be formed in the lowermost plate-like body 46a. Further, since there is no other plate-like body on the upper side of the uppermost plate-like body 46e, the good reforming portion 50 cannot always be formed on the uppermost plate-like body 46e. Accordingly, the lowermost plate 46a and the uppermost 46e may not be used for a product. Here, as an example, the plate-like bodies 46b to 46d having other plate-like bodies on the upper and lower sides are used for the product, and the lowermost plate-like body 46a and the uppermost plate-like body 46e are not used for the product. explain. The lowermost plate-like body 46a and the uppermost plate-like body 46e are not limited to the case where they are not used in the product, and the plate-like bodies 46a and 46e are used in the product as long as a predetermined quality is satisfied. It may be.

  Each of the plate-like bodies 46b to 46d is, for example, a glass substrate. As the glass substrates 46b to 46d, for example, multi-component glass substrates are used. More specifically, the glass substrates 46b to 46d are made of alkali-free glass. The glass substrates 46b to 46d are not limited to multi-component glass substrates. The plate-like bodies 46b to 46d made of various materials can be processed objects.

  The lowermost plate-like body 46a and the uppermost plate-like body 46e may be made of a material different from the plate-like bodies 46b to 46d, or may be the same material as the plate-like bodies 46b to 46d. Here, the same material as that of the plate bodies 46b to 46d is used as the plate bodies 46a and 46e.

  The thickness of each of the plate-like bodies 46b to 46d is, for example, about 100 μm. The thicknesses of the plate-like bodies 46b to 46d are not limited to 100 μm and can be set as appropriate. The thickness of each of the plate-like bodies 46a and 46e is, for example, about 1 mm. The thickness of the plate-like bodies 46a and 46e is not limited to 1 mm, and can be set as appropriate.

  Next, the laser beam A is irradiated to the irradiation planned portion. FIG. 12A shows a stage where the irradiation of the laser beam A is started on the irradiation scheduled portion. The traveling direction of the laser beam A is a direction from one main surface (upper surface in FIG. 12A) side of the workpiece 16 toward the other main surface (lower surface in FIG. 12A). The position (starting point) of the condensing point 56 of the laser light A at the stage where the irradiation of the laser light A is started at the planned irradiation position is below the interface between the glass substrate 46a and the glass substrate 46b. As the laser beam A, for example, an ultrashort pulse laser beam is used. The ultra-short pulse laser beam is used as the laser beam A. When the ultra-short pulse laser beam is used, the fine and good modified portion 50 can be formed, and consequently the fine and good hole 52 is formed. This is because it is possible. Here, for example, femtosecond laser light having a pulse width of about 800 fs is used as the laser light. Note that the pulse width of the ultrashort pulse laser light is not limited to 800 fs, and can be set as appropriate. The wavelength of the laser light is, for example, about 1045 nm. Note that the wavelength of the laser light is not limited to 1045 nm, and can be set as appropriate. The diameter of the cross section of the laser beam A at the condensing point 56 is, for example, about φ2.6 μm. The diameter of the cross section of the laser beam A at the condensing point 56 is not limited to φ2.6 μm, and may be set as appropriate according to the diameter of the hole 52 to be formed.

Similarly to the first embodiment, the converging point 56 of the laser beam A is sent from the other main surface (the lower surface in FIG. 12A) side of the workpiece 16 to the one main surface (FIG. 12A). ) In the direction toward the upper surface) side. The pulse energy E per unit area of the laser beam A irradiated onto the workpiece 16, the feed speed v of the condensing point 56 of the laser beam A, and the repetition frequency f of the laser beam A are not particularly limited. Similarly to the first embodiment, it is possible to set so as to satisfy Expression (1), Expression (5), and Expression (7). Here, the pulse energy E per unit area of the laser beam A irradiated to the workpiece 16 is, for example, about 0.18 × 10 ⁶ [J / m ² ]. The feed speed v of the condensing point 56 of the laser beam A is set within a range of 1 mm / s to 20 mm / s, for example. Here, the feed speed v of the condensing point 56 of the laser beam A is 20 mm / s. Here, the repetition frequency f of the laser beam A is set to 100 kHz, for example.

  FIG. 12B is a cross-sectional view showing a state where the condensing point 56 of the laser beam A is moved halfway. As can be seen from FIG. 12B, the modified portion 56 is formed up to the location where the laser beam A is moved.

  FIG. 12C is a cross-sectional view showing a state where the condensing point 56 of the laser light A is moved above the interface between the glass substrate 46d and the glass substrate 46e. The position (end point) at which the irradiation of the laser beam A is terminated is above the interface between the glass substrate 46d and the glass substrate 46e. As can be seen from FIG. 12C, the modified portion 50 is formed so as to reach the end point from the start point of the irradiation with the laser beam A.

  In the present embodiment, the laser beam A is irradiated with the glass substrates 46a to 46e being superposed for the following reason. That is, when the modified portion 50 is formed by simply irradiating the laser beam A on a single glass substrate, the good modified portion 50 is not necessarily obtained, and hence the good hole 52 is not necessarily obtained. There is a case. Specifically, a defect may occur in the upper part or the lower part of the hole 52. The reason why a good modified portion 50 may not be obtained if a single glass substrate is simply irradiated with the laser beam A is that the processing threshold of the surface layer portion of the glass substrate exposed in the air is excessively low. It is thought that it is because. On the other hand, if the laser light is irradiated with the glass substrates 46a to 46e being stacked as in the present embodiment, the glass substrates 46b to 46d are in a state where the surface layer portions of the glass substrates 46b to 46d are not exposed in the air. Thus, the reforming part 50 is formed. Since the surface layer portions of the glass substrates 46b to 46d are not exposed in the air, the processing threshold value of the surface layer portions of the glass substrates 46b to 46d can be prevented from becoming excessively low. For this reason, according to this embodiment, the favorable modified | denatured part 50 can be formed in the glass substrates 46b-46d, and by extension, the favorable hole 52 can be formed in the glass substrates 46b-46d. For this reason, in this embodiment, the laser light A is irradiated with the glass substrates 46a to 46e being overlapped.

  FIG. 13A shows a state in which the irradiation with the laser beam A is completed for all the irradiation scheduled portions. When the irradiation of the laser beam A is completed for all the irradiation planned locations, the workpiece 16 is removed from the stage 18.

Next, as shown in FIG.13 (b), it etches with respect to each glass substrate 46b-46d. As the etching method, for example, wet etching is used. As described above, also in this embodiment, for example, multi-component glass substrates are used as the glass substrates 46b to 46d. Therefore, also in this embodiment, an etching solution containing hydrofluoric acid (HF) that is a first chemical solution that reacts with the first component and a second chemical solution that is an acidic chemical solution that reacts with the second component is used. Use. As the second chemical solution, for example, nitric acid (NHO ₃ ), hydrochloric acid (HCl), or sulfuric acid (H ₂ SO ₄ ) can be used as in the first embodiment. The mixing ratio of the first chemical solution and the second chemical solution can be set as appropriate as in the first embodiment.

  Next, as shown in FIG. 13C, a via (through electrode) 54 is formed by embedding a conductor in the hole 52.

  Thus, a glass processed part in which the via 54 is embedded in the hole 52 is obtained.

(Evaluation results)
Evaluation results of the laser processing method and the glass processing component manufacturing method according to the present embodiment will be described with reference to FIG. FIG. 14 is a view showing an SEM image in which holes formed in the glass substrate are observed from the upper surface side of the glass substrate. FIG. 14A shows Example 6, that is, the case of this embodiment. In Example 6, the holes 52 were formed by irradiating the laser beam A with a plurality of glass substrates stacked and then etching the modified portion 50. FIG. 14B shows the case of Comparative Example 3. In Comparative Example 3, a hole 252 was formed by irradiating one glass substrate with the laser beam A and then etching the modified portion 50.

  As can be seen from FIG. 14B, in the case of the comparative example 3, a defect has occurred in the upper portion of the hole 252.

  On the other hand, in the case of Example 6, that is, in the case of this embodiment, a good hole 52 was obtained.

  Thus, according to the present embodiment, the modified portion 50 is formed by irradiating the laser beam A with the plurality of plate-like bodies 46a to 46e being overlapped. In the plate-like bodies 46b to 46d whose upper and lower sides are sandwiched by other plate-like bodies, the laser beam A is irradiated in a state where the surface layer portion is not exposed in the air. For this reason, in the plate-like bodies 46b to 46d whose upper and lower sides are sandwiched by other plate-like bodies, it is possible to prevent the processing threshold from being extremely lowered. For this reason, according to this invention, the favorable modified part 50 can be formed in the plate-shaped bodies 46b-46d by which the upper and lower sides were pinched | interposed by the other plate-shaped bodies, and by extension, the upper and lower sides are other plate-shaped bodies. Good holes 52 can be formed in the plate-like bodies 46b to 46d sandwiched between the two.

[Modified Embodiment]
The present invention is not limited to the above embodiment, and various modifications are possible.

  For example, in the second embodiment, the case where the laser light source 10 emits the ultrashort pulse laser light A has been described as an example, but the present invention is not limited to this. For example, the laser light A emitted from the laser light source 10 may be a short pulse laser light having a pulse width larger than that of the ultrashort pulse laser light. For example, the laser light A emitted from the laser light source 10 may be a nanosecond laser light, or the laser light A emitted from the laser light source 10 may be a picosecond laser light. A nanosecond laser beam is a laser beam having a pulse width on the order of nanoseconds. A picosecond laser beam is a laser beam having a pulse width on the order of picoseconds.

  In the first embodiment, the case where the modified portion 50 is formed by irradiating the single glass substrate 46 with the laser beam A has been described as an example. However, the present invention is not limited to this. In 1st Embodiment, you may make it irradiate the laser beam A in the state which accumulated the some glass substrate like 2nd Embodiment. In the first embodiment, if the laser light A is irradiated in a state where a plurality of glass substrates are stacked, it is possible to surely prevent the hole 52 from being lost at the upper part or the lower part of the hole 52, which is better. A simple hole 52 can be formed.

  Moreover, although the said embodiment demonstrated the case where the laser beam A was irradiated to a desired location by moving the stage 18, it is not limited to this. For example, the laser beam A may be irradiated to a desired location using a galvanometer mirror (not shown) and an Fθ (F-Theta) lens (not shown).

  Moreover, although the case where the hole 52 was a through-hole was demonstrated to the example in the said embodiment, the hole 52 is not limited to a through-hole. The present invention can also be applied to the case where the hole 52 having the bottom surface is formed.

  Regarding the above embodiment, the following additional notes are disclosed.

(Appendix 1)
While moving the condensing point of the ultra-short pulse laser light traveling in the direction from one main surface of the glass substrate toward the other main surface, moving from the other main surface side of the glass substrate to the one main surface side Irradiating the glass substrate with the ultrashort pulse laser light to form a modified portion on the glass substrate;
A step of opening a hole in the glass substrate by etching the modified portion,
When the energy per unit area of the ultrashort pulse laser beam is E, the moving speed of the condensing point of the ultrashort pulse laser beam is v, and the repetition frequency of the ultrashort pulse laser beam is f,
0.05 × 10 ⁶ [J / m ² ] ≦ E ≦ 0.5 × 10 ⁶ [J / m ² ],
0.22 × 10 ⁻¹² [m · s] ≦ (v / f ² ) ≦ 10 × 10 ⁻¹² [m · s],
A laser processing method that satisfies 0.018 × 10 ¹⁸ [J / (m ³ · s)] ≦ (E · f ² /v)≦0.81×10 ¹⁸ [J / (m ³ · s)].

(Appendix 2)
A process of stacking a plurality of plates,
The focusing point of the pulse laser beam traveling in the direction from one main surface of the stacked body in which the plurality of plate-shaped bodies are stacked to the other main surface is set to the one from the other main surface side of the stacked body. Irradiating the stacked body with the pulsed laser light while gradually moving to the main surface side of the plate, and forming a modified portion on the plate-like body,
Forming a hole in the plate-like body by etching the modified portion.

(Appendix 3)
The laser processing method according to appendix 2, wherein the pulse laser is an ultrashort pulse laser beam.

(Appendix 4)
The laser processing method according to appendix 2 or 3, wherein the plate-like body is a glass substrate.

(Appendix 5)
The glass substrate is a multi-component glass substrate including at least a silicon oxide that is a first component and a second component that is a component different from the first component;
The step of forming a hole in the plate-like body includes hydrofluoric acid that is a first chemical solution that reacts with the first component and a second chemical solution that is an acidic chemical solution that reacts with the second component. The laser processing method according to appendix 1 or 4, wherein the modified portion is etched using an etchant.

(Appendix 6)
The second component is magnesium oxide or calcium oxide;
The laser processing method according to appendix 5, wherein the second chemical liquid is nitric acid, hydrochloric acid, or sulfuric acid.

(Appendix 7)
The condensing point of the ultrashort pulse laser beam traveling in the direction from one main surface of the glass substrate to the other main surface is gradually moved from the other main surface side of the glass substrate to the one main surface side. And forming a modified portion on the glass substrate by irradiating the glass substrate with the ultrashort pulse laser light, and
A step of opening a hole in the glass substrate by etching the modified portion,
When the energy per unit area of the ultrashort pulse laser beam is E, the moving speed of the condensing point of the ultrashort pulse laser beam is v, and the repetition frequency of the ultrashort pulse laser beam is f,
0.05 × 10 ⁶ [J / m ² ] ≦ E ≦ 0.5 × 10 ⁶ [J / m ² ],
0.22 × 10 ⁻¹² [m · s] ≦ (v / f ² ) ≦ 10 × 10 ⁻¹² [m · s],
0.018 × 10 ¹⁸ [J / (m ³ · s)] ≦ (E · f ² /v)≦0.81×10 ¹⁸ [J / (m ³ · s)] Method.

(Appendix 8)
A process of stacking a plurality of glass substrates;
A condensing point of pulsed laser light traveling in a direction from one main surface of the stacked body in which the plurality of glass substrates are stacked to the other main surface is arranged from the other main surface side of the stacked body to the one main surface. Irradiating the stack with the pulsed laser light while gradually moving to the main surface side, thereby forming a modified portion on the glass substrate;
Forming a hole in the glass substrate by etching the modified portion.

(Appendix 9)
The manufacturing method of the glass processing component of appendix 7 or 8 which further has the process of embedding a conductor in the said hole.

(Appendix 10)
A light source that emits ultrashort pulse laser light;
The condensing point of the ultrashort pulse laser light traveling in the direction from one main surface of the glass substrate to the other main surface is moved from the other main surface side of the glass substrate to the one main surface side. However, by irradiating the glass substrate with the ultrashort pulse laser light, and having a control unit for forming a modified portion on the glass substrate,
When the energy per unit area of the ultrashort pulse laser beam is E, the moving speed of the condensing point of the ultrashort pulse laser beam is v, and the repetition frequency of the ultrashort pulse laser beam is f,
0.05 × 10 ⁶ [J / m ² ] ≦ E ≦ 0.5 × 10 ⁶ [J / m ² ],
0.22 × 10 ⁻¹² [m · s] ≦ (v / f ² ) ≦ 10 × 10 ⁻¹² [m · s],
A laser processing apparatus that satisfies 0.018 × 10 ¹⁸ [J / (m ³ · s)] ≦ (E · f ² /v)≦0.81×10 ¹⁸ [J / (m ³ · s)].

(Appendix 11)
A light source that emits pulsed laser light;
A focusing point of the pulsed laser light traveling in a direction from one main surface of the stacked body in which a plurality of plate-shaped bodies are stacked to the other main surface is set to the one from the other main surface side of the stacked body. A control unit that forms a modified portion on the plate-like body by irradiating the stacked body with the pulsed laser light while gradually moving to the main surface side of the plate.

16 ... Processing object 30 ... Mirror 32 ... Lens 46 ... Glass substrates 46a to 46e ... Plate-like body 48 ... Stacking body 50 ... Modified portions 52, 152, 252 ... Hole 54 ... Via 56 ... Condensing point

Claims (10)

While moving the condensing point of the ultra-short pulse laser light traveling in the direction from one main surface of the glass substrate toward the other main surface, moving from the other main surface side of the glass substrate to the one main surface side Irradiating the glass substrate with the ultrashort pulse laser light to form a modified portion on the glass substrate;
A step of opening a hole in the glass substrate by etching the modified portion,
When the energy per unit area of the ultrashort pulse laser beam is E, the moving speed of the condensing point of the ultrashort pulse laser beam is v, and the repetition frequency of the ultrashort pulse laser beam is f,
0.05 × 10 ⁶ [J / m ² ] ≦ E ≦ 0.5 × 10 ⁶ [J / m ² ],
0.22 × 10 ⁻¹² [m · s] ≦ (v / f ² ) ≦ 10 × 10 ⁻¹² [m · s],
A laser processing method that satisfies 0.018 × 10 ¹⁸ [J / (m ³ · s)] ≦ (E · f ² /v)≦0.81×10 ¹⁸ [J / (m ³ · s)]. A process of stacking a plurality of plates,
The focusing point of the pulse laser beam traveling in the direction from one main surface of the stacked body in which the plurality of plate-shaped bodies are stacked to the other main surface is set to the one from the other main surface side of the stacked body. Irradiating the stacked body with the pulsed laser light while gradually moving to the main surface side of the plate, and forming a modified portion on the plate-like body,
Forming a hole in the plate-like body by etching the modified portion.   The laser processing method according to claim 2, wherein the pulse laser is an ultrashort pulse laser beam.   The laser processing method according to claim 2, wherein the plate-like body is a glass substrate. The glass substrate is a multi-component glass substrate including at least a silicon oxide that is a first component and a second component that is a component different from the first component;
The step of forming a hole in the plate-like body includes hydrofluoric acid that is a first chemical solution that reacts with the first component and a second chemical solution that is an acidic chemical solution that reacts with the second component. The laser processing method according to claim 1, wherein the modified portion is etched using an etchant. The second component is magnesium oxide or calcium oxide;
The laser processing method according to claim 5, wherein the second chemical liquid is nitric acid, hydrochloric acid, or sulfuric acid. The condensing point of the ultrashort pulse laser beam traveling in the direction from one main surface of the glass substrate to the other main surface is gradually moved from the other main surface side of the glass substrate to the one main surface side. And forming a modified portion on the glass substrate by irradiating the glass substrate with the ultrashort pulse laser light, and
A step of opening a hole in the glass substrate by etching the modified portion,
When the energy per unit area of the ultrashort pulse laser beam is E, the moving speed of the condensing point of the ultrashort pulse laser beam is v, and the repetition frequency of the ultrashort pulse laser beam is f,
0.05 × 10 ⁶ [J / m ² ] ≦ E ≦ 0.5 × 10 ⁶ [J / m ² ],
0.22 × 10 ⁻¹² [m · s] ≦ (v / f ² ) ≦ 10 × 10 ⁻¹² [m · s],
0.018 × 10 ¹⁸ [J / (m ³ · s)] ≦ (E · f ² /v)≦0.81×10 ¹⁸ [J / (m ³ · s)] Method. A process of stacking a plurality of glass substrates;
A condensing point of pulsed laser light traveling in a direction from one main surface of the stacked body in which the plurality of glass substrates are stacked to the other main surface is arranged from the other main surface side of the stacked body to the one main surface. Irradiating the stack with the pulsed laser light while gradually moving to the main surface side, thereby forming a modified portion on the glass substrate;
Forming a hole in the glass substrate by etching the modified portion. A light source that emits ultrashort pulse laser light;
The condensing point of the ultrashort pulse laser light traveling in the direction from one main surface of the glass substrate to the other main surface is moved from the other main surface side of the glass substrate to the one main surface side. However, by irradiating the glass substrate with the ultrashort pulse laser light, and having a control unit for forming a modified portion on the glass substrate,
When the energy per unit area of the ultrashort pulse laser beam is E, the moving speed of the condensing point of the ultrashort pulse laser beam is v, and the repetition frequency of the ultrashort pulse laser beam is f,
0.05 × 10 ⁶ [J / m ² ] ≦ E ≦ 0.5 × 10 ⁶ [J / m ² ],
0.22 × 10 ⁻¹² [m · s] ≦ (v / f ² ) ≦ 10 × 10 ⁻¹² [m · s],
A laser processing apparatus that satisfies 0.018 × 10 ¹⁸ [J / (m ³ · s)] ≦ (E · f ² /v)≦0.81×10 ¹⁸ [J / (m ³ · s)]. A light source that emits pulsed laser light;
A focusing point of the pulsed laser light traveling in a direction from one main surface of the stacked body in which a plurality of plate-shaped bodies are stacked to the other main surface is set to the one from the other main surface side of the stacked body. A control unit that forms a modified portion on the plate-like body by irradiating the stacked body with the pulsed laser light while gradually moving to the main surface side of the plate.