JP2007301624A - Cleaving device and cleaving method - Google Patents

Abstract

The object of the present invention is to cut a substrate to be processed along a vertical plane corresponding to a planned cutting line so as to reduce the amount of soggy.
The cleaving apparatus of the present invention locally heats a substrate to be processed 60 made of a brittle material along a planned cutting line 71, and causes cracks in the substrate to be processed 60 due to thermal stress generated at that time. It will be cut off. The cleaving device irradiates the laser beam LB locally to the substrate holder 50 that holds the substrate to be processed 60 and the laser beam irradiation position LP along the planned cutting line 71 of the substrate to be processed 60 held by the substrate holder 50. Heating to irradiate the heating light HB having a wavelength different from that of the laser heating unit 30 to the laser heating unit 30 to be heated and the heating light irradiation position HP different from the laser light irradiation position LP of the laser light LB in the vicinity of the planned cutting line 71. And a light irradiation unit 35. The inside of the substrate to be processed 60 of the substrate to be processed 60 is heated along the side of the planned cutting line 71 by the heating light HB irradiated from the heating light irradiation unit 35.
[Selection] Figure 2

Description

  The present invention relates to a cleaving apparatus and a cleaving method for irradiating a workpiece substrate with laser light and cleaving due to thermal stress. Regarding the method.

  Conventionally, as a method of cleaving a work substrate made of a brittle material, the work substrate made of a brittle material is locally heated using laser light, and is locally cooled by water fog or the like. There has been proposed a method in which cracks are generated in the substrate to be processed by the thermal stress (see Patent Document 1).

In such a method for cleaving a substrate to be processed, the quality of the cleaving of the substrate to be processed is very important in practice. Generally, in a rectangular glass substrate or the like used in a liquid crystal panel or the like, the quality of the cleaving is evaluated by linearity and the amount of sedges. As shown in FIG. 8, “linearity” refers to the linearity of the breaking line 68 on the surface of the substrate 60 to be processed (the deviation δw _{1 of the} breaking line 68 from the planned breaking line 71). Means the perpendicularity in the thickness direction of the split section 68a with respect to the surface of the substrate 60 to be processed (the deviation δw ₂ of the split section 68a from the vertical plane corresponding to the planned cutting line 71). In an actual product, an upper limit is determined for the linearity and the amount of sedges. Specifically, the linearity is about ± several tens μm or less (± several hundreds μm or less), and the amount of soge is about ± several tens μm or less (± several hundreds μm or less). These numbers vary depending on the manufacturer and product. For example, when cutting a processed substrate having a length of 1900 mm × width of 2200 mm and a thickness of 0.7 mm, the linearity is ± 50 μm or less. The amount of soge is preferably about ± 70 μm (= thickness × 10%) or less.

  The following is considered as a reason why such a sedge (the split section 68a deviates from a vertical plane corresponding to the planned cutting line 71) (see, for example, Non-Patent Document 1). That is, when the substrate 60 to be processed is heated and cooled to cleave, the heated cleave line 71 is cooled, thereby generating a tensile stress on the cleave line 71 of the substrate 60 and causing a crack to develop. At this time, since the surface of the substrate 60 to be heated and the immediately lower portion thereof are heated to a high temperature, the progress of cracks going to proceed inside is suppressed. As a result, a large sodge occurs.

Conventionally, it is known to irradiate a substrate to be processed 60 with a plurality of laser beams (for example, Patent Document 2). However, the purpose of irradiating a plurality of laser beams in this way is to process the substrate 60 to be processed quickly, and not to reduce the amount of soggy. For this reason, naturally, the heating light irradiation position HP different from the laser light irradiation position LP of the laser light is irradiated with heating light having a wavelength different from that of the laser heating portion, and the inside of the substrate to be processed 60 is lateral to the planned cutting line 71. There is no mention of heating along (see FIG. 2 (b)).
Japanese National Patent Publication No. 8-509947 JP 2003-574401 A Thermal stress analysis in glass laser scribe (Precision Engineering Society Vol.71 No.12)

  The present invention has been made in consideration of such points, and provides a cleaving apparatus and a cleaving method for cleaving a substrate to be processed along a vertical plane corresponding to a cleaving line and reducing the amount of soggy. Objective.

  The present invention relates to a cleaving apparatus that heats a substrate to be processed made of a brittle material locally along a planned cutting line and generates a crack in the substrate to be processed by thermal stress generated at that time. A substrate holder for holding the substrate, a laser heating unit for locally heating the laser beam irradiation position along the planned cutting line of the substrate to be processed held by the substrate holder, and the vicinity of the planned cutting line In this case, the heating light irradiation position different from the laser light irradiation position of the laser light is irradiated with heating light having a wavelength different from that of the laser heating portion, and the inside of the substrate to be processed is heated along the side of the cutting line. And a light irradiation unit.

  With such a configuration, the substrate to be processed can be cleaved by a vertical plane corresponding to the planned cleaving line, and the amount of soggy can be kept small.

  The present invention is a cleaving apparatus characterized in that the heating light irradiated from the heating light irradiation unit is irradiated to a heating light irradiation position on one side of the planned cutting line.

  With such a configuration, the temperature distribution in the substrate to be processed can be efficiently and substantially symmetric with respect to the planned cutting line.

  The present invention is a cleaving apparatus characterized in that the heating light irradiated from the heating light irradiation section has an absorptance of 90% or less with respect to the substrate to be processed, and heats the inside of the substrate to be processed.

  With such a configuration, the inside of the substrate to be processed can be efficiently heated.

  The present invention is a cleaving apparatus characterized in that the heating light irradiated from the heating light irradiation section has an absorptance of 90% or less with respect to the substrate to be processed, and forms a focal point inside the substrate to be processed.

  With such a configuration, the inside of the substrate to be processed can be efficiently heated.

  The present invention is a cleaving apparatus characterized in that the heating light irradiated from the heating light irradiation unit is a laser beam.

  The present invention is the cleaving apparatus characterized in that the laser light emitted from the heating light irradiation unit has a wavelength of approximately 2700 nm to 4500 nm.

  The present invention is a cleaving apparatus characterized in that the laser light emitted from the heating light irradiation unit is composed of HF laser light, semiconductor laser light, or YAG laser light having a long wavelength converted.

  The present invention is a cleaving apparatus in which a columnar lens or a columnar mirror is further provided between the heating light irradiation unit and the substrate to be processed.

  With such a configuration, the manufacturing cost of the cleaving device can be kept low.

  The present invention is characterized in that the shape of the heating light irradiation position irradiated to the substrate to be processed through the columnar lens or columnar mirror from the heating light irradiation unit is an elliptical shape whose long side extends along the planned cutting line. This is a cleaving device.

  With such a configuration, the temperature distribution in the substrate to be processed can be efficiently and substantially symmetric with respect to the planned cutting line.

  In the present invention, the laser heating unit has a laser light oscillator that irradiates laser light, the heating light irradiation unit has a heating light oscillator that irradiates heating light, and the laser light oscillator is disposed between the laser light oscillator and the substrate to be processed. A first reflecting portion that reflects the laser light emitted from the laser light oscillator and is swingably connected to the swing shaft, and is provided between the heating light oscillator and the substrate to be processed. The cleaving device is characterized in that it includes a second reflecting portion that reflects the heating light emitted from the first reflecting portion and is slidably connected to the oscillating shaft at a side of the first reflecting portion. .

  With such a configuration, it is possible to reduce the space necessary for arranging the cleaving device.

  The present invention is the cleaving apparatus characterized in that the heating light irradiated from the heating light irradiation unit is incoherent light.

  The present invention is a cleaving apparatus characterized in that the heating light irradiation unit has a plurality of unit heating light irradiation units that irradiate heating light having different wavelengths.

  With such a configuration, the substrate to be processed can be cleaved under conditions suitable for the properties of the substrate to be cleaved, and the amount of soggy can be further reduced.

  The present invention relates to a cleaving method in which a substrate to be processed made of a brittle material is locally heated along a planned cutting line, and the substrate to be processed is cracked by thermal stress generated at that time. A holding step for holding the substrate, a laser heating step for locally heating the laser beam irradiation position along the planned cutting line of the held substrate by irradiating the laser beam, and the vicinity of the planned cutting line A heating light irradiation process in which the heating light irradiation position different from the laser light irradiation position of the laser light is irradiated with heating light having a wavelength different from that of the laser heating unit, and the inside of the substrate to be processed is heated along the side of the cutting line. And a cleaving method characterized by comprising:

  According to the present invention, the inside of the substrate to be processed is cleaved by irradiating the heating light irradiation position near the planned cutting line and different from the laser light irradiation position of the laser light with the heating light having a wavelength different from that of the laser heating unit. By heating along the side of the planned line, the substrate to be processed can be cleaved by a vertical plane corresponding to the planned cleaved line, thereby reducing the amount of soggy.

First Embodiment Hereinafter, a first embodiment of a cleaving apparatus according to the present invention will be described with reference to the drawings. Here, FIG. 1 to FIG. 5 are diagrams showing a first embodiment of the present invention.

  As shown in FIG. 1, the cleaving apparatus according to the present invention locally heats a substrate to be processed 60 made of a brittle material along a planned cutting line 71 and causes the substrate 60 to be processed by thermal stress generated at that time. Cracks are generated and cleaved. In the present application, a bonded substrate 60 in which two glass substrates (a front plate 61 and a back plate 62) are bonded via sealing materials (adhesives) 65a and 65b is used as the substrate 60 to be cleaved. (See FIG. 2 (a)). Moreover, the liquid crystal 66 is dripped in the compartment formed by the front surface plate 61, the back surface plate 62, and the sealing materials 65a and 65b (see FIG. 2A).

As shown in FIG. 1, the cleaving apparatus according to the present invention includes a substrate holder 50 that holds a bonded substrate 60 by a holding unit 51 and a planned cutting line 71 of the bonded substrate 60 that is held by the holding unit 51 of the substrate holder 50. a laser heating unit 30 for locally heating the laser beam irradiation position LP (see FIG. 2 (b)) is irradiated with a CO ₂ laser beam (laser beam) LB along and in the vicinity of the planned cutting line 71, A heating light irradiation position HP (see FIG. 2B) different from the laser light irradiation position LP of the CO ₂ laser light LB is irradiated with a heating laser light (heating light) HB having a wavelength different from that of the laser heating unit 30 and bonded. A heating light irradiation unit 35 that heats the inside of the substrate 60 along the side of the planned cutting line 71 is provided.

In this case, the heating light irradiation position HP of the heating laser light HB is located on one side of the planned cutting line 71 and partially overlaps the laser light irradiation position LP of the CO ₂ laser light LB, but the laser light irradiation position LP And not exactly match.

  Further, as shown in FIG. 1, the laser heating unit 30 moves relative to the bonding substrate 60 held by the holding unit 51 of the substrate holder 50 and is locally localized by the laser heating unit 30 on the downstream side of the laser heating unit 30. A cooling unit 40 is provided that locally cools the planned cutting line 71 that is heated locally at the cooling position CP (see FIG. 2B).

  As shown in FIG. 1, the substrate holder 50 is provided on a moving stage 55 that moves relative to the laser heating unit 30, the heating light irradiation unit 35, and the cooling unit 40. Moreover, as shown in FIG. 1, the laser heating unit 30, the heating light irradiation unit 35, and the cooling unit 40 are configured to move relatively along the planned cutting line 71 on the bonding substrate 60.

  Hereinafter, the details of the laser heating unit 30, the heating light irradiation unit 35, and the cooling unit 40 will be described.

(Laser heating unit 30)
First, the laser heating unit 30 will be described in detail. As shown in FIG. 1, the laser heating unit 30 causes the bonding substrate 60 to crack by irradiating the bonding substrate 60 with CO ₂ laser light LB to locally heat the bonding substrate 60. because are those of the laser beam oscillator 37 that emits tens W~ hundred W about CO ₂ laser beam LB, which reflects the CO ₂ laser beam LB incident from the laser beam oscillator 37 through a lens 31a The reflection mirror 38 and the scanning mirror 39 that scans the CO ₂ laser beam LB reflected by the reflection mirror 38 on the bonding substrate 60 are provided. For this reason, the CO ₂ laser beam LB emitted from the laser beam oscillator 37 is reflected by the scanning mirror 39 via the reflection mirror 38 and within the predetermined length L along the planned cutting line 71 on the bonding substrate 60. By repeatedly scanning, the laser beam LB having the irradiation pattern is generated. As a means for scanning the CO ₂ laser beam LB, a rotary polygon mirror may be used instead of using the scanning mirror as described above.

2B, the linear CO ₂ laser beam LB has a linear irradiation pattern extending in a direction along the planned cutting line 71. As shown in FIG. The width (the length in the direction orthogonal to the planned cutting line 71) W of the CO ₂ laser beam LB is about several millimeters to several tens of millimeters, and the length (the length in the direction along the planned cutting line 71). L is preferably about several mm to a hundred mm.

(Heating light irradiation unit 35)
Next, the heating light irradiation unit 35 will be described in detail. As shown in FIG. 1, the heating light irradiation unit 35 includes a heating laser light oscillator (heating light oscillator) 32 that irradiates a heating laser light HB having an absorption rate of 90% or less with respect to the bonding substrate 60, and a heating laser light oscillator. 32 and the columnar lens 21 provided between the bonding substrate 60 and the laminated substrate 60.

  Moreover, as shown in FIG. 1, the heating laser beam HB irradiated from the heating light irradiation part 35 is irradiated to the bonding board | substrate 60 via the columnar lens 21, The shape of the heating light irradiation position HP is as follows. As shown in FIG. 2B, the long side has an elliptical shape extending along one side of the planned cutting line 71. If such a columnar lens 21 is used, it is not necessary to provide a mechanism for scanning the heating laser beam HB on one side of the planned cutting line 71, and the manufacturing cost of the cutting apparatus can be kept low. In addition, as shown in FIG.2 (b), the heating light irradiation position HP is located in the other side of the sealing material 65a with respect to the cutting projected line 71. FIG.

  As described above, instead of irradiating the bonding substrate 60 with the heating laser beam HB irradiated from the heating beam irradiation unit 35 via the columnar lens 21, the heating laser beam irradiated from the heating beam irradiation unit 35 is used. HB may be reflected by a columnar mirror (not shown) and applied to the bonding substrate 60.

  By the way, since the heating laser beam HB irradiated from the heating beam irradiation unit 35 has an absorptivity of 90% or less with respect to the surface plate 61 of the bonded substrate 60, the heating laser beam HB is placed inside the surface plate 61. While forming the focus FS, the inside of the surface plate 61 can be heated. Specifically, the heating laser beam HB is configured to form a focal point FS having a diameter φ at the position of the internal depth ε of the surface plate 61 (see FIG. 2A). The heating laser beam HB preferably has a wavelength of approximately 2700 nm to 4500 nm. Examples of such heating laser light HB include HF laser light, semiconductor laser light, and long-wavelength converted YAG laser light.

2A shows a cross-sectional view of the bonding substrate 60 that is irradiated with the CO ₂ laser beam LB and the heating laser beam HB, and FIG. 2B shows the CO ₂ laser beam LB. FIG. 2C is a plan view of the bonding substrate 60 that is irradiated with the heating laser beam HB, and FIG. 2C shows the CO ₂ laser beam LB and the heating laser beam HB with respect to the thickness direction of the bonding substrate 60. It shows the strength of.

(Cooling unit 40)
Next, the cooling unit 40 will be described in detail. As shown in FIG. 1, the cooling unit 40 is locally cooled by spraying the coolant C on the planned cutting line 71 of the bonded substrate 60 heated locally by the CO ₂ laser beam LB of the laser heating unit 30. Is to do. As the coolant C, water and mist (a mixture of water and gas), a gas such as nitrogen and helium, a fine particle solid such as carbon dioxide particles (dry ice), a liquid such as alcohol, a mist-like alcohol, snow Dry ice or the like can be used.

  Moreover, as shown in FIG. 1, the cooling unit 40 includes a cooling nozzle 41 that injects the coolant C onto the surface of the bonded substrate 60. In addition, it is preferable that the diameter (inner diameter) of this cooling nozzle 41 is several mm or less.

  Note that the laser heating unit 30, the heating light irradiation unit 35, and the cooling unit 40 shown in FIG. 1 are all aligned in a straight line at appropriate intervals along the planned cutting line 71 on the bonding substrate 60. It can be adjusted.

  Next, the operation of the present embodiment having such a configuration will be described.

(Cleaving method)
First, with reference to FIG. 1, FIG. 2 (a)-(c), and FIG. 5, the method to cleave the bonding board | substrate 60 which dripped the liquid crystal 66 inside is demonstrated.

  First, the bonding substrate 60 is prepared as follows. That is, the sealing materials 65a and 65b (thickness 5 μm) are applied to predetermined portions of the back plate 62 (thickness 0.7 mm) (sealing material application step 81) (see FIGS. 2A and 5).

  Next, on the back surface plate 62, the liquid crystal 66 is dropped into a section surrounded by the sealing materials 65a and 65b (liquid crystal dropping step 82) (see FIGS. 2A and 5).

  Next, the front surface plate 61 (thickness 0.7 mm) is joined to the back surface plate 62 via the sealing materials 65a and 65b and vacuum-sealed. Thus, the bonding board | substrate 60 is manufactured (bonding process 83) (refer Fig.2 (a) and FIG. 5).

  Next, the bonding board | substrate 60 is hold | maintained by the holding part 51 of the board | substrate holder 50 (bonding process 84a) (refer FIG.1 and FIG.5).

Next, the laser heating unit 30 irradiates the CO ₂ laser beam LB to the laser beam irradiation position LP along the planned cutting line 71 of the surface plate 61 of the bonded substrate 60 held by the substrate holder 50 and locally heats it. (Laser heating step 85a) (see FIGS. 1, 2A to 2C, and FIG. 5). Here, as described later, since the CO ₂ laser beam LB is absorbed by the surface plate 61 made of glass, the surface plate 61 is heated and a thermal stress is generated in the vicinity of the planned cutting line 71.

At this time, the heating laser beam HB (for example, HF laser beam) having a wavelength different from that of the CO ₂ laser beam LB irradiated from the laser beam oscillator 37 is applied to the heating beam irradiation position HP on one side of the planned cutting line 71 of the surface plate 61. ) To heat the inside of the bonding substrate 60 along the side of the cutting line 71 (heating light irradiation step 86) (see FIGS. 1, 2A to 2C, and FIG. 5). .

  In this case, as will be described later, by limiting the wavelength of the heating laser beam HB, the inside of the surface plate 61 of the bonded substrate 60 can be sufficiently heated, and the amount of soot generated when the surface plate 61 is cleaved. Can be suppressed. In addition, (suppression of the amount of sores) and (wavelength limitation of the heating laser beam HB) will be described later.

Thereafter, the cleaving line 71 of the surface plate 61 heated locally by the laser heating unit 30 is locally cooled by the cooling unit 40 (cooling step 87a). By cooling in this way, the surface of the surface plate 61 contracts and tensile stress is generated. For this reason, the stress induced by the CO ₂ laser beam LB can be increased, and the surface plate 61 can be efficiently cleaved by the cleaved planned line 71 (see FIGS. 1 and 5).

  Next, the bonding substrate 60 is turned over (inverted), and the turned bonding substrate 60 is held by the holding portion 51 of the substrate holder 50 (holding step 84b) (see FIGS. 1 and 5).

Next, the laser heating unit 30 irradiates the laser beam irradiation position LP along the planned cutting line 71 of the back surface plate 62 of the bonded substrate 60 held by the holding unit 51 of the substrate holder 50 with the CO ₂ laser beam LB. Heat locally (laser heating step 85b) (see FIGS. 1 and 5).

  Finally, the cutting line 71 of the back plate 62 heated locally by the laser heating unit 30 is locally cooled by the cooling unit 40 (cooling step 87b) (see FIGS. 1 and 5). By this, a crack enters into the cutting planned line 71 of the back surface plate 62 of the bonding substrate 60, and the bonding substrate 60 can be cut. Then, the cut bonded substrate 60 is unloaded from the holding unit 51.

(Reducing the amount of soge)
Next, with reference to FIGS. 3 (a) and 3 (b), a method for reducing and suppressing the amount of soggy generated when the surface plate 61 is cleaved will be described. 3A and 3B schematically show the temperature distribution in the bonding substrate 60. FIG.

1 and 3 (b), the heat generated by the CO ₂ laser beam LB from the laser heating unit 30 on the planned cutting line 71 of the surface plate 61 of the bonding substrate 60 is distant from the laser beam irradiation position LP seal It is transmitted to the back plate 62 via a seal material 65a that is closer than the material 65b. In fact, as shown in FIG. 3B, the isotherm (indicated by a broken line) indicating the temperature distribution in the surface plate 61 has a shape greatly deviated from the planned cutting line 71 toward the sealing material 65a. Heat is transmitted to the back plate 62 through the sealing material 65a.

As described above, the heat generated by the CO ₂ laser beam LB is transmitted to the back plate 62 through the sealing material 65a, so that the temperature in the vicinity of the sealing material 65a of the front surface plate 61 is increased. A tensile stress is generated in the vicinity of the sealing material 65a of the surface plate 61. For this reason, as shown in FIG. 3B, the fractured surface 68 a formed by heating and cooling the surface plate 61 is bent toward the sealing material 65 a side with respect to the planned fracture line 71.

  The soge is generated when heat is transferred asymmetrically with respect to the planned cutting line 71 of the substrate to be processed. Therefore, the surface plate 61 and the back plate 62 are bonded to each other by the sealing materials 65a and 65b as described above. It may occur not only when the laminated substrate 60 is cleaved but also when, for example, a single glass substrate is cleaved.

  According to the present invention, the laser beam HB having a wavelength at which the absorption rate of the surface plate 61 is 90% or less is irradiated on the opposite side of the sealing material 65a with respect to the planned cutting line 71 of the surface plate 61. The inside of the composite substrate 60 can be heated on the opposite side of the sealing material 65 a with respect to the planned cutting line 71. For this reason, the temperature distribution in the surface plate 61 can be formed substantially symmetrically with a good balance with respect to the planned cutting line 71. As a result, as shown in FIG. 3A, it is possible to suppress the amount of shading in the split section 68 a that occurs when the surface plate 61 is cut.

  In addition, the isothermal line which shows the temperature distribution in the surface slope 61 at this time is a shape substantially symmetrical with respect to the cutting planned line 71, as shown to Fig.3 (a).

  Moreover, since the temperature in the surface plate 61 can be raised by irradiating the heating laser beam HB from the heating light irradiation unit 35, a large tensile stress can be generated on the planned cutting line 71 of the surface plate 61. it can. For this reason, the cleaving speed of the surface plate 61 can be improved.

(Limiting the wavelength of the heating laser beam HB)
Next, the reason for irradiating the heating laser beam HB having a wavelength at which the absorptivity at the surface plate 61 is 90% or less will be described with reference to FIG. FIG. 4 is a graph showing the relationship between the wavelength of light and the transmittance of the light through a glass substrate (thickness 0.7 mm).

As shown in FIG. 4, the transmittance when the glass substrate is irradiated with light varies depending on the wavelength, and when the light having a wavelength of 5000 nm or more is irradiated, the transmittance is almost 0%. Since the wavelength of the CO ₂ laser beam LB emitted from the laser heating unit 30 is 10,000 nm, the transmittance with respect to the glass substrate is very low, and almost all is near the surface of the glass substrate (several tens of μm). Absorbed. For this reason, the surface of the front plate 61 and the back plate 62 can be efficiently heated by using the CO ₂ laser beam LB as the laser beam LB irradiated to the front plate 61 and the back plate 62 made of glass.

However, since almost all of the CO ₂ laser beam LB is absorbed in the vicinity of the surface of the surface plate 61 made of glass as described above, the inside of the surface plate 61 cannot be heated. As a result, even if the intensity of the CO ₂ laser beam LB emitted from the laser heating unit 30 is adjusted, it is difficult to adjust the temperature inside the surface plate 61.

  According to the present invention, the inside of the surface plate 61 of the bonded substrate 60 can be efficiently heated by irradiating the heating laser beam HB having a wavelength at which the absorption rate at the surface plate 61 is 90% or less. . As a result, the temperature distribution in the surface plate 61 can be formed in a substantially balanced manner with a good balance with respect to the planned cutting line 71, and the amount of soggy can be kept small.

  Note that it is preferable to use HF laser light as the heating laser light HB. This is because, since the wavelength of the HF laser light is 2.9 μm, the transmittance of the surface plate 61 is about 55% (see FIG. 5), and the inside of the surface plate 61 can be efficiently heated. .

  The above-described effects when the wavelength of the heating laser beam is limited will be described in more detail.

The CO ₂ laser beam LB emitted from the laser heating unit 30 has a constant intensity in the atmosphere, but when it enters the surface plate 61 that is a glass substrate, the intensity becomes zero at a depth of several tens of μm. (See FIG. 2C). On the other hand, unlike the CO ₂ laser beam LB, the heating laser beam HB having a wavelength at which the absorption rate at the surface plate 61 is 90% or less is transmitted to the inside of the surface plate 61, and the intensity I = I ₀ × It has exp (−αd) (see FIG. 2C). Here, d represents an arbitrary depth with respect to the thickness direction of the surface plate 61, and α represents the transmittance coefficient of the glass.

When the diameter φ of the focal point FS of the heating beam light formed in the surface plate 61 is represented by φ (d) = F (d−ε), the temperature θ at the focal point FS of the heating laser beam HB is θ 、 exp (−αd) × F (d−ε) ² Here, ε represents the depth of the focal point FS of the heating laser beam HB with respect to the thickness direction of the surface plate 61.

  Therefore, the wavelength of the heating laser beam HB is selected (this corresponds to selecting α), and the function F and the depth ε of the focal point FS are adjusted to appropriately adjust the temperature in the surface plate 61. Can be adjusted.

  In the above description, the heating laser light HB is used as the heating light emitted from the heating light irradiation unit 35. However, the present invention is not limited to this, and incoherent light may be used as the heating light.

  Moreover, the heating light irradiation part 35 may consist of the several unit heating light irradiation part (not shown) which irradiates the heating light from which a wavelength mutually differs. As described above, the heating light irradiation unit 35 has a plurality of unit heating light irradiation units that irradiate heating light having different wavelengths, so that it matches the optical characteristics of the surface plate 61 of the bonded substrate 60 to be cleaved. The heating laser beam HB having a more appropriate wavelength can be selected. As a result, it is possible to further reduce the amount of sedge generated when the surface plate 61 is cleaved. Note that each of the unit heating light irradiators has substantially the same configuration as the heating light irradiator 35 described above.

First Modification Next, a first modification of the present invention will be described with reference to FIG. In the first modification shown in FIG. 6, the heating light irradiation unit 35 emits the heating laser light HB, and the reflection mirror that reflects the heating laser light HB emitted by the heating laser light oscillator 32. 33 and a scanning mirror 34 that scans the bonding substrate 60 with the heating laser beam HB reflected by the reflection mirror 33 and incident through the lens 31b. Other configurations are substantially the same as those of the first embodiment shown in FIGS.

  In the first modification shown in FIG. 6, the same parts as those of the first embodiment shown in FIGS. 1 to 5 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the first modified example shown in FIG. 6, the heating laser beam HB emitted from the heating laser beam oscillator 32 is reflected by the scanning mirror 34 through the reflection mirror 33, and with respect to the planned cutting line 71 in the surface plate 61. Scanning is performed on the opposite side of the sealing material 65a. Thus, the temperature distribution in the surface plate 61 is cleaved by irradiating the heating laser beam HB from the heating light irradiation unit 35 on the opposite side to the sealing material 65a with respect to the cleaving line 71 of the surface plate 61. It can be formed substantially symmetrically with good balance with respect to the planned line 71. For this reason, it is possible to suppress the amount of soggy generated on the surface plate 61.

  As a means for scanning the heating laser beam HB, a rotary polygon mirror may be used instead of using the scanning mirror 34 as described above.

Second Modification Next, a second modification of the present invention will be described with reference to FIG. The second modification shown in FIG. 7 includes a scanning mirror 39 provided between the laser light oscillator 37 and the bonding substrate 60 and a scanning provided between the heating laser light oscillator 32 and the bonding substrate 60. Instead of the mirror 34, a single scanning scanner 45 is provided. The scanning scanner 45 is provided between the laser light oscillator 37 and the bonding substrate 60, reflects the CO ₂ laser light LB emitted from the laser light oscillator 37, and can swing with respect to the swing shaft 48. The first reflection unit 46 connected to the heating laser beam oscillator 32 and the bonding substrate 60 are provided to reflect the heating laser beam HB emitted from the heating laser beam oscillator 32, and the first reflection unit 46 and a second reflecting portion 47 that is swingably connected to the swing shaft 48. Other configurations are substantially the same as those of the first modification shown in FIG.

  In the second modification example shown in FIG. 7, the same parts as those in the first modification example shown in FIG.

In a second modification shown in FIG. 7, CO ₂ laser beam LB emitted by the laser beam oscillator 37 is reflected by the first reflecting portion 46 is repeatedly scanned with respect to expected splitting line 71 on the surface plate 61 Thus, the laser beam LB having the irradiation pattern is generated. Further, the heating laser beam HB emitted from the heating laser beam oscillator 32 is reflected by the second reflecting portion 47 and scanned on the surface plate 61 on the opposite side of the sealing material 65 a with respect to the planned cutting line 71. Thus, the single scanning scanner 45 can scan the CO ₂ laser light LB emitted from the laser light oscillator 37 and the heated laser light HB emitted from the heating laser light oscillator 32. For this reason, the space required to arrange the cleaving device can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS The longitudinal cross-sectional view which shows the whole 1st Embodiment of the cleaving apparatus by this invention. The figure which shows the to-be-processed substrate irradiated with the laser beam and the heating laser beam in 1st Embodiment of the cleaving apparatus by this invention. Sectional drawing for demonstrating the effect obtained by irradiating with a heating laser beam in 1st Embodiment of the cleaving apparatus by this invention. The graph which shows the relationship between the transmittance | permeability in the to-be-processed substrate which consists of glass of the said light in the 1st Embodiment of the cleaving apparatus by this invention. The flowchart which shows 1st Embodiment of the cleaving method by this invention. The longitudinal cross-sectional view which shows the whole the 1st modification of the cleaving apparatus by this invention. The perspective view which shows the 2nd modification of the cleaving apparatus by this invention. The perspective view for demonstrating the linearity of the cutting line of a to-be-processed substrate, and the orthogonality (sedge amount) of a cut surface.

Explanation of symbols

21 Columnar Lens 30 Laser Heating Unit 32 Heating Light Oscillator 35 Heating Light Irradiation Unit 37 Laser Light Oscillator 46 First Reflecting Unit 47 Second Reflecting Unit 48 Oscillating Shaft 50 Substrate Holder 60 Bonding Substrate (Substrate Substrate)
71 Scheduled cutting line 84 Holding process 85 Laser heating process 86 Heating light irradiation process LP Laser light irradiation position LB Laser light HP Heating light irradiation position HB Heating laser light (heating light)

Claims (13)

In a cleaving apparatus that heats a substrate to be processed made of a brittle material locally along a planned cutting line and generates a crack in the substrate to be processed by thermal stress generated at that time,
A substrate holder for holding the substrate to be processed;
A laser heating unit that irradiates a laser beam to a laser beam irradiation position along the planned cutting line of the substrate to be processed held by the substrate holder and locally heats the laser beam;
The heating light irradiation position different from the laser beam irradiation position of the laser beam near the planned cutting line is irradiated with heating light having a wavelength different from that of the laser heating unit, and the inside of the substrate to be processed is lateral to the cutting target line. A heating light irradiation section for heating along
A cleaving device comprising:   The cleaving apparatus according to claim 1, wherein the heating light irradiated from the heating light irradiation unit is irradiated to a heating light irradiation position on one side of the planned cutting line.   2. The cleaving apparatus according to claim 1, wherein the heating light irradiated from the heating light irradiation section has an absorptance of 90% or less with respect to the substrate to be processed, and heats the inside of the substrate to be processed.   2. The cleaving apparatus according to claim 1, wherein the heating light irradiated from the heating light irradiation unit has an absorptance of 90% or less with respect to the substrate to be processed, and forms a focal point inside the substrate to be processed.   2. The cleaving apparatus according to claim 1, wherein the heating light irradiated from the heating light irradiation unit is a laser beam.   6. The cleaving apparatus according to claim 5, wherein the laser light emitted from the heating light irradiation unit has a wavelength of approximately 2700 nm to 4500 nm.   6. The cleaving apparatus according to claim 5, wherein the laser light emitted from the heating light irradiator comprises HF laser light, semiconductor laser light, or YAG laser light having a long wavelength converted.   6. The cleaving apparatus according to claim 5, further comprising a columnar lens or a columnar mirror provided between the heating light irradiation unit and the substrate to be processed.   The shape of the heating light irradiation position irradiated to the substrate to be processed through the columnar lens or columnar mirror from the heating light irradiation unit is an elliptical shape having a long side extending along a planned cutting line. 8. The cleaving device according to 8. The laser heating unit has a laser light oscillator that irradiates laser light,
The heating light irradiation unit has a heating light oscillator that radiates heating light,
Between the laser light oscillator and the substrate to be processed, a first reflecting portion that reflects the laser light emitted from the laser light oscillator and is swingably connected to the swing shaft is provided.
A heating light irradiated from the heating light oscillator is reflected between the heating light oscillator and the substrate to be processed, and the second reflection light is connected to the swing shaft at a side of the first reflecting portion and swingably. The cleaving apparatus according to claim 1, further comprising a second reflecting portion.   The cleaving apparatus according to claim 1, wherein the heating light irradiated from the heating light irradiation unit is incoherent light.   The cleaving apparatus according to claim 1, wherein the heating light irradiation unit includes a plurality of unit heating light irradiation units that irradiate heating light having different wavelengths. In a cleaving method in which a substrate to be processed made of a brittle material is locally heated along a planned cutting line, and the substrate to be processed is cracked by thermal stress generated at that time.
A holding step for holding the substrate to be processed;
A laser heating step of locally heating the laser beam irradiation position to the laser beam irradiation position along the planned cutting line of the held substrate;
The heating light irradiation position different from the laser beam irradiation position of the laser beam near the planned cutting line is irradiated with heating light having a wavelength different from that of the laser heating unit, and the inside of the substrate to be processed is lateral to the cutting target line. A heating light irradiation process for heating along
A cleaving method characterized by comprising:

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