JP2017019704A - Method and apparatus for cutting hard fragile plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for cutting a thermoplastic hard fragile plate being a comparatively thin glass plate and other plates such as the display substrate of a portable terminal without the occurrence of microcrack and cullet.SOLUTION: A method for cutting a thermoplastic hard fragile plate w comprises: moving an irradiation point P of a laser beam B along the cutting line of the thermoplastic hard fragile plate w fixed on a table 1; pressing and moving a scribe cutter on the cutting line heated by the irradiation of the laser beam B and softened s on a front surface side; pressing and extending the front surface of the glass plate without generating micro cracks by softening s the front surface side of the glass plate w just before scribing when pressing the cutter on the glass plate w to form a scribe groove; and cutting the glass plate w by vertical cracks extended from the tip of the scribe groove.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a cleaving method and apparatus particularly suitable for cleaving (breaking and cutting) a glass plate or other thin thermoplastic rigid / brittle plate used for a display of a portable terminal.

  The cutting of the glass plate is usually performed by two steps of scribe and break. Scribe is a crack (vertical) in a direction perpendicular to the surface of the glass plate by running a scribe cutter (hereinafter simply referred to as “cutter”) consisting of a roller with a sharp edge or a sharp needle along the cutting line. Crack). Breaking is a process of dividing a glass plate by growing vertical cracks by applying local stress to the scribed breaking line.

  FIG. 4 is a diagram showing an example of a cleaving device that breaks due to thermal stress of a laser beam. In FIG. 4, w is a glass plate to be cleaved, a is a breaking line of the glass plate w, 1 is a table for fixing the glass plate w, 21 is a guide girder mounted on a non-illustrated immovable member, and 2 is a guide girder. 21 is a moving table that travels along 21, d is the moving direction of the moving table 2 when the glass plate w is cleaved, 4 is a cutter mounted on the moving table 2 via the urging cylinder 26, and 3 is mounted on the moving table 2 The laser oscillator, Q is the pressing point of the cutter 4, and P is the irradiation point of the laser beam B irradiated from the laser oscillator 3. The irradiation point P of the laser beam is located rearward in the moving direction when the glass plate is cut at the pressing point Q of the cutter.

  In the apparatus of FIG. 4, the cutter 4 and the laser oscillator 3 are moved along the breaking line a of the glass plate w fixed to the table 1 by moving the movable table 2 in the arrow direction d in the figure. Immediately after scribing, local thermal stress is applied by the laser beam B, and the glass plate w is cut.

  FIG. 5 is an enlarged cross-sectional view schematically showing a scribed glass plate. A scribe groove g having a V-shaped cross section along the breaking line a is formed on the surface of the glass plate w (the surface on the side where the cutter 4 is pressed), and a vertical crack c is generated from the bottom end toward the back surface of the glass plate. ing.

  On the other hand, a small crack m called a horizontal crack or microcrack is generated on the wall surface of the scribe groove g on the surface side of the glass plate w due to the force that the cutter 4 pushes it to both sides with the cutting line a as a boundary. Along with this, cullet (fine glass particles that are chipped and scattered) is generated.

  The microcrack m grows by an external force acting on the glass plate at the time of transporting the glass plate after the cleaving or in a subsequent process, and causes the glass plate to be damaged. Moreover, in a glass substrate for a display, the scattered cullet adheres to the surface of the glass substrate and does not peel off, resulting in a defective substrate caused by a defective circuit pattern formed on the glass plate or a poorly attached polarizing plate. Will occur.

  As another method of cutting the glass plate, the applicant of the present application provided a protrusion along the cutting line of the glass plate on the table that vacuum-sucks the glass plate, and when the glass plate was sucked on the table 1, the cutting was performed. A cleaving method that omits the break process is proposed in which bending stress is applied along the line and the cutter is run along the cleaving line in that state (Patent Document 1). As a cutting method that eliminates the need for scribing, a method of cutting a glass plate only by a process of irradiating a laser beam along a cutting line has been put into practical use.

JP 2003-261345 A

  A glass substrate used for a display of a portable terminal is strongly required to be thin in order to reduce the size and weight. For example, the glass plate used for the display of a smart phone has been 0.3 mm or 0.2 mm, but has become 0.15 mm. There is a request to do. It is difficult for such a thin glass plate to grind the cleaved edge after cleaving. In addition, since the price competition of mobile terminals is fierce, reduction of manufacturing cost is also an important issue.

  When a glass substrate with a thickness of about 0.15 mm for a display of a portable terminal is cleaved by a scribe-break method and the subsequent process is performed without grinding the cleaved edge, the damage (cracking) of the substrate in the subsequent process increases. To do. In addition, the occurrence of defective products due to the scattered cullet adhering to the glass substrate increases.

  According to the method of cutting a glass plate with only a laser beam without performing scribing, microcracks are not generated, and therefore, generation of a defective substrate due to cracks and adhesion of cullet in the subsequent process can be prevented. However, cutting with a laser beam alone is due to thermal stress, so the effect of heat transfer rate is large. Especially when the glass plate is thin, the heat diffusion is fast, so the stress difference is difficult to occur. It is difficult to set conditions by thickness.

  Furthermore, when cutting only with a laser, a thin and powerful laser is required, so a powerful and expensive laser oscillator must be used, and there is a problem that the apparatus cost and running cost required for cutting increase. Further, in the method of cleaving by the scribe by the cutter and the break by the laser, the microcracks generated at the time of the scribe remain even after the break, and thus the above problem cannot be solved.

  The present invention has been made to solve the above-described problems, and an object thereof is to obtain a cleaving method and apparatus capable of cutting a relatively thin glass plate without generating microcracks or cullet.

  In the method for cleaving a thermoplastic hard brittle plate according to the present invention, the irradiation point P of the laser beam B is moved along the desired cleaving line a of the thermoplastic hard brittle plate w fixed on the table 1 to irradiate the laser beam B. A step of pressing and moving the scribe cutter 4 on the breaking line a heated by the surface and softened on the surface side. The cleaving of the present invention includes a scribing step for generating a vertical crack c in the glass plate w, and is characterized in that the surface side of the glass plate w is softened by irradiation with a laser beam B immediately before scribing. .

  Immediately before scribing, the surface side of the glass plate w is softened so that when the cutter 4 is pressed against the glass plate w, the surface of the glass plate is expanded without causing microcracks to form a scribe groove g. The glass plate w is cut by the vertical crack c extending from the tip of the scribe groove g.

  The depth of the softened region can be adjusted by the intensity of the laser beam B preceding the cutter 4, and the scribe groove g having a desired depth can be formed without causing microcracks. When scribing with a normal roller cutter, vertical cracks enter 0.3 to 0.4 mm. Therefore, if a thin glass plate such as a substrate having a thickness of 0.15 mm is used, the vertical crack c is removed from the glass plate w when scribing. Breakless cleaving that does not require a break process by reaching the back surface can be realized. Moreover, the breakless cleaving of a thicker glass plate can be performed by scribing with the bending stress applied to the cut portion of the glass plate w as disclosed in Patent Document 1.

  The present invention is not characterized by breakless cleaving, and it is possible to prevent the occurrence of microcracks on the surface side of the glass plate against which the cutter is pressed during scribing, resulting in defective products due to adhesion of cullet, etc. It is intended to reduce the occurrence of. Therefore, for example, when a relatively thick glass plate is cut, the surface side of the glass plate is softened by the laser beam B preceding the cutter 4, and then scribe is performed by the cutter 4. Further, after the scribing, the thermal shock by the laser is performed. It is also possible to break with a break.

  Microcracks do not occur in the vertical crack c and the fractured surface on the back side of the glass plate on which the vertical crack is grown. In the method of the present invention, the surface side of the glass plate on which the scribe groove g is engraved is softened to prevent generation of microcracks and cullet on the glass plate surface side during scribing. Accordingly, the cracked section of the glass plate cleaved by the method of the present invention does not generate microcracks or cullet, and can prevent generation of defective products due to breakage of the glass plate after cleaving or adhesion of cullet.

  As described above, the cleaving of the thermoplastic hard brittle plate according to the method of the present invention can suppress microcracks that occur during scribing, and can suppress the occurrence of cullet during scribing, so there are no microcracks or chips. A split section of the mirror surface can be obtained, and the occurrence of defective products due to breakage of the glass plate after cleaving and adhesion of cullet can be greatly reduced.

  Especially when cleaving a thin glass plate that is used as a display board for a portable terminal, it can be cleaved without break, and it has a lower output than the method of cutting only with a laser beam or the method of breaking with a laser beam after scribing. The laser oscillator can be used, and the conditions of the laser beam at the time of cutting can be easily set, so that the manufacturing cost of the substrate can be reduced.

The perspective view which shows an example of the cleaving apparatus of an Example Schematic partial cross-sectional view of a softened glass plate Schematic partial cross-sectional view of a glass plate scribed with a softened surface A perspective view showing an example of a conventional cleaving device Schematic enlarged cross-sectional view of a glass plate scribed by a conventional method

  Embodiments of the present invention will be described below with reference to the drawings. The cleaving apparatus of the present invention is different from the conventional apparatus shown in FIG. 4 in that the front-rear relationship between the irradiation point P of the laser beam and the pressing point Q of the cutter 4 with respect to the moving direction d of the moving table 2 at the time of cleaving is reversed. It is a point. That is, in the apparatus of the present invention, the glass plate w is heated by the laser beam B prior to the generation of the vertical crack by the scribe cutter 4.

  During scribing of the glass plate w, the laser beam irradiation point P moves along the breaking line a prior to the pressing point Q of the scribe cutter 4 by the movement of the moving table 2, and the surface side of the glass plate w is softened. Let Then, the scribe cutter 4 is pressed and moved on the surface of the glass plate that has been softened, whereby a scribe groove g is formed, which is perpendicular to the portion of the glass plate that is not softened from the tip of the scribe groove g. A crack c (see FIG. 3) is generated.

  In FIG. 1 showing an example of the cleaving apparatus of the present invention, w is a glass plate to be cleaved, a is a cleaving line of the glass plate w, 1 is a table for fixing the glass plate w, and 21 is mounted on a non-illustrated immovable member. The guide girder 2, 2 is a moving base that is screwed into a feed screw 23 that rotates forward and backward by a feed motor 22 and travels along the guide girder 21, d is the moving direction of the moving base 2 when the glass plate w is scribed, 24 is a lifting motor provided on the moving table 2, 25 is a lifting table guided by a vertical guide provided on the moving table 2, and is lifted by the lifting motor 24, 3 is a cutter mounted on the lifting table 25, and 26 is a cutter. 4 is an urging cylinder for applying a pressing force to 4, 3 is a laser oscillator mounted on the movable table 2 through a height adjuster 27 for focus adjustment, Q is a pressing point of the cutter 4, and P is irradiated from the laser oscillator 3. Irradiation point of the laser beam B, Is located in the band of adhered by thin narrow in Table 1 material immediately below the cutting line a (projection on the table. For example narrow adhesive tape.). The irradiation point P of the laser beam is located in front of the moving direction when the glass plate scribes the pressing point Q of the cutter.

  The upper surface of the table 1 is provided with a large number of suction holes (not shown) communicated with a vacuum source, and the glass plate w placed on the table 1 has a negative pressure acting on the suction holes. It is adsorbed and fixed. When the cutting line a is positioned immediately above the strip 5 and the glass plate w is adsorbed, as shown in an exaggerated manner in FIGS. By bending, tensile stress is applied to the upper surface side and compressive stress is applied to the lower surface side of the portion of the glass plate.

  In this state, if necessary, the table 1 is moved so that the cutting line a of the glass plate w is positioned on the movement trajectory of the laser beam irradiation point P and the scribe cutter pressing point Q, and the laser beam B is irradiated. While the cutter 4 is pressed against the glass plate w by the cylinder 26, the moving table 2 is moved in the moving direction d during scribing. Then, the irradiation point P of the laser beam on the cutting line is heated and softened s (FIG. 2), and the scribe cutter 4 is pressed to the softened s to form a scribe groove g, and a vertical crack is formed at the tip. c is generated (FIG. 3), and the bending stress in which the upper part acting on this portion is the tensile side is promoted, the growth of the vertical crack c is promoted to reach the back surface of the glass plate w, and the glass plate w is cleaved. The By this action, the glass plate w is continuously cut as the moving table 2 moves.

  Although the above example shows an example in which the band material 5 stuck on the table 1 is cleaved in a state in which bending stress is applied to the breaking line a portion of the glass plate w, as described above, the thickness of the glass plate w When the thickness is thin, breakless cleaving is possible without applying bending stress to the portion of the cleaving line a. For a thick glass plate that cannot be brokenlessly cut using the band material 5, after scribing, the elevating platform 25 is raised so that the cutter 4 is separated from the glass plate w with the laser beam B. By moving the moving table 2 back while irradiating, it is possible to break by thermal break caused by laser.

  It is also effective to use a fiber laser that has high energy conversion efficiency, high output, no optical axis shift, and excellent beam quality as the laser. If a fiber laser is used, the distance between the tip of the output fiber and the cutter can be made narrower, and the position of the tip of the output fiber can be adjusted with a screw or the like in the moving direction of the moving table. It is relatively easy to adjust the interval between the laser beam irradiation point P and the cutter pressing point Q in accordance with the material and thickness of the plate.

1 Table 3 Laser oscillator 4 Scribe cutter a Split line B Laser beam c Vertical crack g Scribe groove P Irradiation point s Softening w Glass plate

Claims (3)

  The irradiation point of the laser beam is moved along a desired breaking line of the hard brittle plate fixed on the table, and the scribe cutter is moved on the breaking line heated by the irradiation and softened on the surface side. Cleaving method of hard brittle board.   Irradiation of the laser beam in a state in which a protrusion is provided on a portion of the table below the breaking line, and a hard brittle plate fixed on the table is caused to bend upward with the breaking line as a ridge. The method for cleaving a hard brittle plate according to claim 1, wherein the point is moved and the pressing point of the scribe cutter is moved.   A table that sucks and fixes the hard brittle plate to be cleaved with negative pressure air, a moving table that moves above the table parallel to the table surface, and a laser beam that is mounted on the moving table and that is mounted on the moving table. A laser oscillator for irradiating the plate and a scribe cutter biased toward the hard brittle plate, and the moving table moves the irradiation point of the laser beam preceding the pressing point of the scribe cutter at the time of scribing A crushing device for hard brittle plates that moves in the direction of movement.

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