JP5194076B2 - Laser cleaving device - Google Patents

Description

  The present invention relates to a laser cleaving apparatus.

  Conventionally, as a method for cleaving a brittle material substrate such as a glass substrate, a cutter wheel or the like is pressed and rolled to form a scribe line composed of vertical cracks, and then an external force is applied from the direction perpendicular to the substrate along the scribe line. In addition, methods for cleaving the substrate are widely used.

  Usually, when scribing a brittle material substrate using a cutter wheel, the mechanical stress imparted to the brittle material substrate by the cutter wheel is likely to cause defects in the substrate, and when the substrate is cleaved by applying external force, Cracks or the like due to defects may occur.

  Therefore, in recent years, a method of cleaving a brittle material substrate using a laser has been put into practical use. In this method, the substrate is irradiated with a laser beam to heat the substrate to a temperature lower than the melting temperature, and then the substrate is cooled by a cooling medium, thereby generating thermal stress on the substrate. Are formed with cracks (hereinafter sometimes referred to as “vertical cracks”). In this method of cleaving a brittle material substrate using a laser beam, since the thermal stress is used, the tool is not brought into direct contact with the substrate, the fractured surface becomes a smooth surface with few chips and the strength of the substrate is maintained. The

  In order to deepen the vertical crack in the so-called laser cleaving method, it is necessary to increase the laser beam irradiation output or slow down the scanning speed. However, if the laser beam irradiation output is increased, the substrate surface may be damaged by heating. May occur. Further, if the scanning speed of the laser beam is decreased, the processing efficiency is lowered.

  Therefore, a technique for deepening vertical cracks by bending the substrate and irradiating a laser beam in that state has been proposed. For example, in Patent Document 1, the substrate is curved by adsorbing and fixing the substrate on a stage. Further, in Patent Document 2, the substrate is bent by its own weight by changing the height of the support member.

JP-A-7-323384 JP 2007-191363 A

  However, in the proposed technique of Patent Document 1, since the substrate is held on a stage on which a protrusion having a predetermined height or a predetermined curved surface is formed, it corresponds to the curved surface state of the substrate in order to curve the substrate into a desired shape. Each stage had to be used. In addition, when the substrate is thick, the substrate may not be sufficiently curved and cannot be fixed to the stage. Further, even in the proposed technique of Patent Document 2, when the substrate is thick, the substrate may not be sufficiently bent by its own weight.

  An object of the present invention is to provide a laser cleaving apparatus that can bend and fix a substrate to a desired shape without changing the fixing base and even when the substrate is thick.

  According to the present invention, a fixing means for fixing a brittle material substrate, a laser irradiation means, and a cooling means are provided, and the laser irradiation means and the cooling means are moved relative to the substrate to make the laser beam brittle. An apparatus that irradiates a material substrate and heats it to a temperature lower than the melting temperature, blows a cooling medium onto the substrate, cools the substrate, forms vertical cracks by the thermal stress generated on the substrate, and cleaves the substrate. The fixing means includes a fixing base for fixing the substrate, a rod-shaped member for bending the substrate fixed to the fixing table so that the laser beam irradiation surface side is convex, and the rod-shaped member as a center. A pressing member that holds both sides of the substrate against the fixed base, the substrate is placed on the fixed base, and the substrate is pressed and held by the pressing member, and then the substrate is bent by the rod-shaped member. Laser cleaving apparatus characterized by cleaving to form the irradiation and vertical crack in the substrate by performing the spraying of the cooling medium of the laser beam.

  Here, it is preferable that the rod-shaped member is movable between a protruding position and an immersion position with respect to the fixed base, and the substrate is curved by moving the bar-shaped member to a position protruding from the fixed base.

  Further, the amount of protrusion of the rod-shaped member from the fixed base can be switched in at least two stages, the substrate is curved with the rod-shaped member as a first protruding position, and vertical cracks are generated by laser beam irradiation and cooling medium spraying. After forming on the substrate, the substrate may be cleaved by further bending the substrate as a second protruding position that protrudes further than the first protruding position.

  In addition, it is preferable to provide suction fixing means for fixing the substrate to the fixing table.

  In the laser cleaving apparatus according to the present invention, since the substrate is bent by the rod-shaped member after the substrate is held down by the pressing member, the rod-shaped member can be obtained without replacing the fixing base and even when the substrate is thick. The substrate can be bent into a desired shape by adjusting the protruding amount of the member. A deep vertical crack can be formed in the substrate by irradiating the curved substrate with a laser beam.

It is an outline figure showing one embodiment of a laser cleaving device concerning the present invention. It is process drawing in the case of cleaving a board | substrate using the laser cleaving apparatus of FIG. It is process drawing in the case of cleaving a board | substrate using the laser cleaving apparatus of FIG. It is a perspective view explaining the operation state of a laser scribe. It is a figure explaining the movement state at the time of a rod-shaped member moving from a 1st protrusion position to a 2nd protrusion position. It is process drawing in the case of cleaving a board | substrate using the other laser cleaving apparatus which concerns on this invention.

  Hereinafter, although the laser cleaving apparatus according to the present invention will be described in more detail, the present invention is not limited to these embodiments.

  FIG. 1 is a schematic diagram showing an example of a laser cleaving apparatus according to the present invention. In the laser cleaving apparatus of this figure, a brittle material substrate (hereinafter simply referred to as “substrate”) 50 is placed and fixed on a fixing base 11.

  The fixed base 11 has two left and right fixing portions 11a and 11b, and the fixing portion 11a is provided so as to be movable in the left-right direction. Further, a plurality of intake holes (adsorption fixing means) 14 are formed on the surfaces of the fixing portions 11a and 11b, and the plurality of intake holes 14 are connected to a vacuum pump (adsorption fixing means) P. By driving the vacuum pump P and drawing air, the substrate 50 is adsorbed and fixed on the fixing table 11. A rod-like member 12 that is long in the vertical direction (front-rear direction) with respect to the paper surface is located between the center portion of the fixed base 11, that is, between the fixed portion 11 a and the fixed portion 11 b. It is provided so that it can be moved to the immersive position. When the rod-shaped member 12 is in a position protruding from the fixed base 11, the substrate 50 is curved so that the laser beam LB irradiation surface side is convex. This will be described in detail later.

  A support base 31 is provided above the fixed base 11 so as to face the fixed base 11 at a distance. The support base 31 includes a cutter wheel (not shown) for forming a trigger crack on the surface of the substrate 50, an opening for irradiating the substrate 50 with the laser beam LB, and cooling for cooling the surface of the substrate 50. Nozzles 37 (shown in FIG. 4) are provided side by side in the front-rear direction.

  The cutter wheel (not shown) is held so as to be able to move up and down between a position where it is pressed against the substrate 50 and a position where it is not contacted, and a position where the cutter wheel is pressed against the substrate 50 only when a trigger crack is formed as a starting point of the scribe line. To descend. The trigger crack is preferably formed on the inner side of the surface side end of the substrate 50 in order to suppress a pre-cursor phenomenon in which a crack occurs in an unpredictable direction from the trigger crack.

  The laser beam LB emitted from the laser output device 34 is reflected downward by the reflection mirror 44 and is fixed on the fixed base 11 through an opening formed in the support base 31 via an optical system (not shown). Is irradiated.

  Further, water as a cooling medium is ejected together with air from the cooling nozzle 37 (shown in FIG. 4) provided near the opening of the support 31 where the laser beam LB is emitted. The position on the substrate 50 where the cooling medium is ejected is on the scribe line 51 and behind the irradiation region of the laser beam LB (see FIG. 4).

  On both sides of the support base 31 in the left-right direction, rectangular parallelepiped-shaped pressing members 13a, 13b that are elongated in the front-rear direction are provided. These pressing members 13a and 13b can be moved in the left and right direction and the up and down direction by a driving means (not shown). As will be described later, when the substrate 50 is fixed to the fixing base 11, the substrate is centered on the rod-shaped member 12. Hold the left and right sides of 50.

  Above the fixed base 11, a pair of CCD cameras 38 and 39 for recognizing alignment marks preliminarily stamped on the substrate 50 are provided. By these CCD cameras 38 and 39, the position is corrected so that the scribe line 51 (shown in FIG. 4) of the substrate 50 and the rod-like member 12 overlap each other in plan view. Specifically, the position shift of the substrate 50 at the time of setting is detected by the CCD cameras 38 and 39. For example, when the substrate 50 is shifted by the angle θ, the fixed base 11 is rotated by −θ and the substrate 50 is shifted by Y. When this occurs, the fixed base 11 is moved by -Y.

  2 and 3 show process diagrams in the case of cleaving the substrate 50 using the cleaving apparatus having such a configuration. Note that the suction means, the laser beam irradiation means, and the cooling means for sucking and fixing the substrate 50 to the fixing base 11 are omitted from these drawings for the sake of brevity.

  First, the substrate 50 is placed on the fixed base 11, the vacuum pump P (shown in FIG. 1) is driven, and the substrate 50 is sucked and fixed to the fixed base 11 by the intake holes 14 (shown in FIG. 1). Then, the CCD camera 38, 39 images the alignment mark provided on the substrate 50. As described above, the scribe planned line 51 (shown in FIG. 4) of the substrate 50 and the rod-like member 12 are formed based on the imaging data. The fixed base 11 is moved so as to overlap in plan view to position the substrate 50 at a predetermined position (FIG. 2A).

  Next, after the pressing members 13a and 13b are moved to the central portion, the pressing members 13a and 13b are lowered to press and fix the substrate 50 to the fixing base 11 ((b) in the figure). The degree of pressing and fixing of the substrate 50 by the pressing members 13a and 13b is preferably detected by a sensor and controlled to be a predetermined pressing force. Further, the fixing position of the substrate 50 by the pressing members 13a and 13b may be determined as appropriate from the material and thickness of the substrate 50, but when the substrate 50 is bent by the protrusion of the rod-shaped member 12, the radius of curvature of the substrate 50 is 4000 mm. The following is preferable. For this purpose, when the protruding amount of the rod-shaped member 12 is in the range of 5 mm or less, the distance L from the rod-shaped member 12 to the pressing members 13a and 13b is preferably 100 mm or more and 300 mm or less. The pressing members 13a and 13b preferably press the entire front and rear direction of the substrate 50, but may press the substrate 50 at a predetermined interval in the front and rear direction.

  Then, the rod-like member 12 is set as a first protruding position protruding from the fixed base 11. As a result, the substrate 50 is bent ((c) in the figure). As described above, the protrusion amount of the rod-shaped member 12 is preferably such that the radius of curvature of the substrate 50 when the substrate 50 is curved is 4000 mm or less, and is usually in the range of 0.1 mm to 5 mm. .

  Next, as described above, a trigger crack is formed in the substrate 50 by the wheel cutter. Then, a laser beam LB is emitted from the laser output device 34 ((d) in the figure). The laser beam LB is irradiated by the reflecting mirror 44 substantially perpendicularly to the surface of the substrate 50 as shown in FIG. At the same time, water as a cooling medium is ejected from the cooling nozzle 37 in the vicinity of the rear end of the laser beam irradiation region. By irradiating the substrate 50 with the laser beam LB, the substrate 50 is heated in the thickness direction at a temperature lower than the melting temperature, and the substrate 50 tries to thermally expand. Occur. Immediately after the heating, the surface of the substrate 50 is cooled by water, so that the substrate 50 is contracted and a tensile stress is generated. By the action of the tensile stress, the vertical crack 53 is formed on the substrate 50 along the scheduled scribe line 51 starting from the trigger crack. In addition, in the apparatus of the present invention, tensile stress due to the curvature of the substrate 50 is applied to the laser beam irradiation surface side of the substrate 50, so that the vertical crack 53 is formed deeper than usual, and in some cases the vertical crack 53 is formed on the substrate. 50 up to the opposite side.

  Then, by moving the laser beam LB and the cooling nozzle 37 relatively in the front-rear direction according to the scribe line 51, the vertical crack 53 develops in the front-rear direction, and the scribe line 52 is formed on the substrate 50.

The laser beam LB used here is not particularly limited, and may be determined appropriately from the material and thickness of the substrate, the depth of the vertical crack to be formed, and the like. When the brittle material substrate is a glass substrate, a laser beam having a wavelength of 9 to 11 μm, which has a large absorption on the glass substrate surface, is preferably used. An example of such a laser beam is a CO ₂ laser. The shape of the laser beam irradiation spot is preferably an elliptical shape elongated in the relative movement direction of the laser beam. The irradiation length in the relative movement direction is preferably in the range of 10 to 60 mm, and the irradiation width is preferably in the range of 1 to 5 mm.

  Examples of the cooling medium ejected from the cooling nozzle 37 include water and alcohol. Further, an additive such as a surfactant may be added within a range that does not adversely affect the use of the brittle material substrate after cleaving. Usually, the amount of cooling medium sprayed is preferably about several ml / min. The cooling of the substrate by the cooling medium is preferably a so-called water jet method in which water is injected together with gas (usually air) from the viewpoint of rapidly cooling the substrate heated by the laser beam. The cooling region with the cooling medium is preferably circular or elliptical with a major axis of about 1 to 5 mm. The cooling region is preferably formed so that the distance between the center points of the cooling region and the heating region is about several millimeters to several tens of millimeters behind the relative movement direction of the heating region by the laser beam.

  The relative moving speed of the laser beam LB and the cooling nozzle 37 is not particularly limited, and may be appropriately determined from the depth of the vertical crack to be obtained. In general, the slower the relative movement speed, the deeper the vertical cracks that are formed. Usually, the relative movement speed is about several hundred mm / sec.

  Next, the rod-shaped member 12 is further protruded to the second protruding position (FIG. 3E). Thereby, the vertical crack 53 formed in the substrate 50 reaches the opposite surface side of the substrate 50 and the substrate 50 is cleaved. If the vertical crack 53 reaches the opposite side of the substrate 50 in the previous process of forming the vertical crack 53 by irradiation with the laser beam LB, the process shown in FIG. The protruding amount of the rod-shaped member 12 is not particularly limited as long as the vertical crack 53 propagates to the opposite surface side of the substrate 50. Usually, a protruding amount of about 0.1 mm to 1 mm is sufficient from the first protruding position. When the rod-shaped member 12 is moved from the first projecting position to the second projecting position, both ends in the front-rear direction of the rod-shaped member 12 may be projected simultaneously, as shown in FIG. The side end may be protruded first, and the other end side may be protruded with a delay.

  When the substrate 50 is cleaved, the one pressing member 13a rises to release the holding of the substrate 50a, and the fixing portion 11a moves away from the rod-shaped member 12 together with the substrate 50a (FIG. 3 (f)). Thereby, the board | substrates 50a and 50b cut into two are isolate | separated, and generation | occurrence | production of the crack of a broken surface, etc. is prevented. Next, the rod-shaped member 12 moves from the second protruding position to the immersive position ((g) in the figure). In addition, you may perform the process shown in FIG.3 (f) and the same figure (g) simultaneously.

  Then, the fixing of the fixing portion 11a is released, and the substrate 50a is moved to the next step ((h) in the figure). Next, the pressing member 13b is lifted to release the holding of the substrate 50b, and the fixing of the fixing portion 11b is released. And the board | substrate 50b is moved to the predetermined distance beyond the rod-shaped member 12, and the said series of cleaving processes are performed repeatedly.

  There is no particular limitation on the brittle material substrate 50 as a cleaving target of the laser cleaving apparatus according to the present invention, and conventionally known brittle material substrates such as glass, ceramic, silicon, and sapphire can be mentioned. Among these, the laser cleaving apparatus of the present invention can be suitably used for cleaving tempered glass substrates such as chemically tempered glass and air-cooled tempered glass, which have large surface compressive stress and are difficult to cross-scribe. Further, the thickness of the brittle material substrate 50 that can be cleaved by the laser cleaving apparatus of the present invention varies depending on the material of the brittle material substrate 50, but is approximately 2 mm when the brittle material substrate 50 is a glass substrate. .

  FIG. 6 shows another embodiment of the laser cleaving apparatus according to the present invention. The laser cleaving apparatus shown in this figure is different from the apparatus of the above-described embodiment in that the bar-shaped member 12 presses the same surface as the surface pressed by the pressing members 13a and 13b of the substrate 50 to bend the substrate 50. The point is that the laser beam LB is irradiated from the fixed base side of the substrate 50. Hereinafter, a procedure for cleaving the substrate 50 using this apparatus will be outlined with a focus on differences from the apparatus of the above embodiment.

  First, the substrate 50 is sucked and fixed to the fixed base 11 (FIG. 6A). Then, the pressing members 13a and 13b are moved, and both sides of the substrate 50 are pressed and fixed by the pressing members 13a and 13b with the rod-shaped member 12 as the center ((b) in the figure). Next, the rod-shaped member 12 is lowered to curve the substrate 50 (FIG. 3C). As the amount of protrusion of the bar-like member 12 downward from the surface of the fixed base 11, the same range as described above is also exemplified here.

Next, as described above, a trigger crack is formed in the substrate 50 by the wheel cutter. Then, a laser beam LB is emitted from the laser output device 34 ((d) in the figure).
At the same time, water as a cooling medium is ejected from the cooling nozzle 37 (shown in FIG. 4) in the vicinity of the rear end of the laser beam irradiation region, and the vertical crack 53 is formed on the substrate along the scribe line 51 (shown in FIG. 4). 50. Also in the apparatus of this embodiment, since the tensile stress due to the curvature of the substrate 50 is applied to the laser beam irradiation surface side of the substrate 50, the vertical crack 53 is formed deeper than usual. Hereinafter, the same processing as the processing steps shown in FIG. 3 is also performed in the apparatus of this embodiment.

  In the laser cleaving apparatus according to the present invention, the substrate is bent by the rod-shaped member after the substrate is held down by the pressing member, so that the substrate can be formed into a desired shape without changing the fixing base and even when the substrate is thick. Can be curved. By irradiating a curved substrate with a laser beam, deep vertical cracks can be formed in the substrate, which is useful.

DESCRIPTION OF SYMBOLS 11 Fixing base 11a, 11b Fixing part 12 Bar-shaped member 13a, 13b Pressing member 37 Cooling nozzle 50 Brittle material substrate 53 Vertical crack P Vacuum pump LB Laser beam

Claims (4)

A fixing means for fixing the brittle material substrate, a laser irradiation means, and a cooling means are provided, and the laser irradiation means and the cooling means are moved relative to the substrate to irradiate the brittle material substrate with a laser beam. After heating below the melting temperature, the substrate is cooled by spraying a cooling medium on the substrate, and a thermal crack generated on the substrate forms a vertical crack to cleave the substrate,
The fixing means includes: a fixing base for fixing the substrate; a rod-shaped member for bending the substrate fixed to the fixing table so that a laser beam irradiation surface side is convex; and the substrate around the rod-shaped member. A pressing member that holds both sides against the fixed base;
After the substrate is placed on the fixed base and the substrate is held down by the pressing member, the substrate is bent by the rod-shaped member, and laser beam irradiation and cooling medium spraying are performed to cause a vertical crack on the substrate. Laser cleaving apparatus characterized by forming and cleaving.   2. The laser cleaving apparatus according to claim 1, wherein the bar-shaped member is movable to a protruding position and an immersing position with respect to the fixed base, and is bent to move to a position protruding from the fixed base.   The amount of protrusion of the rod-shaped member from the fixed base can be switched to at least two stages, the substrate is curved with the rod-shaped member as a first protruding position, and vertical cracks are formed by irradiating a laser beam and blowing a cooling medium. 3. The laser cleaving apparatus according to claim 2, wherein the substrate is further bent by using the rod-shaped member as a second protruding position that protrudes further than the first protruding position.   The laser cleaving apparatus according to any one of claims 1 to 3, wherein suction fixing means for fixing the substrate to the fixing base is provided.