CN1298523C - Method and device for scribing fragile material substrate - Google Patents

Abstract

A method for scribing a fragile material substrate, comprising the steps of cooling a mother glass substrate (50) in an area in proximity to laser spots (LS) along a predicted scribe line (SL) while continuously radiating laser beam onto the surface of the mother glass substrate (50) so that the laser spots (LS) with a temperature lower than the softening point of the mother glass substrate can be formed along the predicted scribe line (SL) to form a main cooling spot (MCP), whereby cracks can be continuously formed along the predicted scribe line (SL), and an assist cooling spot (ACP) for pre-cooling an area positioned on the laser spot (LS) side of the main cooling spot (MCP) can be formed along the predicted scribe line (SL) in proximity to the main cooling spot (MCP).

Description

Scribing method and scribing device for brittle material substrate

technical field

The present invention relates to a scribing method and a scribing device for forming scribe lines on the surface of brittle material substrates such as glass substrates and semiconductor wafers used in flat panel displays (hereinafter referred to as FPDs). .

Background technique

Hereinafter, the prior art in which a scribe line is formed on a glass substrate, which is one of brittle material substrates used in various flat panel displays, or a mother brittle material substrate bonded to the brittle material substrate will be described. .

In an FPD such as a liquid crystal display panel formed by bonding a pair of glass substrates together, after bonding a pair of mother glass substrates to each other, each mother glass substrate is cut into glass substrates of a predetermined size constituting the FPD. Each mother glass substrate was cut along the scribe line after forming the scribe line by a diamond cutter in advance. Also, depending on the type of flat panel display or the manufacturing method, a scribe line may be formed on the mother glass substrate before bonding to cut the mother glass substrate.

When the scribe line is mechanically formed by a cutter, residual stress accumulates in the peripheral portion of the formed scribe line. When the mother glass substrate is cut along the scribe line, residual stress accumulates in the edge portion and the peripheral portion of the side edge on the surface of the cut and formed glass substrate. Such residual stress is a potential stress that causes unnecessary cracks to extend near the surface of the glass substrate. When the residual stress is released, unnecessary cracks may be generated to break the edge of the truncated surface of the glass substrate. Fragments generated by breaking the edge of the truncated surface of the glass substrate may adversely affect the FPD to be manufactured.

In recent years, in practical use, laser beams are often used to form scribe lines on the surface of a mother glass substrate. In the method of forming a scribe line on a mother glass substrate using a laser beam, as shown in FIG. 8 , the mother glass substrate 50 is irradiated with a laser beam LB from a laser oscillator 61 . The laser beam LB irradiated from the laser oscillator 61 forms an elliptical laser spot LS along the scribing line SL on the mother glass substrate 50 on the surface of the mother glass substrate 50 . The mother glass substrate 50 and the laser beam LB irradiated by the laser oscillator 61 are relatively moved along the longitudinal direction of the laser spot LS.

The mother glass substrate 50 is heated by the laser beam LB to a temperature lower than the temperature at which the mother glass substrate 50 is softened. Thereby, the surface of the mother glass substrate 50 on which the laser spot LS is formed is heated without being softened.

Further, a cooling medium such as cooling water is sprayed from the cooling nozzle 62 to the vicinity of the laser beam LB irradiated area on the surface of the mother glass substrate 50 to form scribe lines. On the surface of the mother glass substrate 50 irradiated by the laser beam LB, compressive stress is generated due to heating by the laser beam LB, and tensile stress is generated due to spraying of a cooling medium. In this way, since the tensile stress is generated in the region adjacent to the region where the compressive stress is generated, a stress gradient based on the respective stresses is generated between the two regions. Starting from the notch TR at the portion, a vertical crack is formed in the thickness direction (vertical direction) of the mother glass substrate 50 along the scribing line SL. That is, the lines of the vertical cracks are scratch lines.

In this way, the vertical cracks formed on the surface of the mother glass substrate 50 are extremely small and generally cannot be seen with the naked eye, so they are called blind cracks BC.

9 is a perspective view schematically showing the formation state of the blind crack BC on the mother glass substrate 50 scribed by the laser scribing device, and FIG. 10 is a plan view schematically showing the physical change state on the mother glass substrate 50 .

The laser beam oscillated by the laser oscillator 61 forms an elliptical laser spot LS on the surface of the mother glass substrate 50 . Irradiation is performed so that the major axis of the laser spot LS coincides with the planned scribing line SL.

In this case, the thermal energy intensity of the laser spot LS formed on the mother glass substrate 50 is greater in the outer peripheral portion than in the central portion. Such a laser spot LS forms a laser beam having a Gaussian distribution of thermal energy intensity, that is, the thermal energy distribution is such that the thermal energy intensity is maximum at each end portion in the major axis direction. Therefore, on each end portion in the long-axis direction on the planned scribing line SL, the heat energy intensity is maximum, and the heat energy intensity of the central portion of the laser spot LS sandwiched between each end portion is higher than that of each end portion. The heat energy intensity is smaller.

The mother glass substrate 50 relatively moves along the long axis direction of the laser spot LS, and therefore, the mother glass substrate 50 receives a large thermal energy intensity at one end of the long axis direction of the laser spot LS along the scribing line SL. After heating, the central portion of the laser spot LS is heated with a small thermal energy intensity, and then heated with a large thermal energy intensity. Thereafter, the cooling medium is sprayed from the cooling nozzle 62 onto the cooling point CP having a predetermined distance L from, for example, the rear end of the laser spot LS in the long-axis direction.

As a result, a temperature gradient is generated between the laser spot LS and the cooling point CP, and a large tensile stress is generated in a region opposite to the laser spot LS with respect to the cooling point CP. Utilizing this tensile stress, vertical cracks are formed in the thickness t direction of the mother glass substrate 50 along the planned scribing line from the notch TR formed in advance at the end of the mother glass substrate 50 .

The mother glass substrate 50 is heated by the elliptical laser spot LS. In this case, although the mother glass substrate 50 transfers heat three-dimensionally from its surface to the inside due to the large thermal energy intensity at one end of the laser spot LS, the laser spot LS is relatively opposite to the mother glass substrate 50. After moving, the portion heated by the front end of the laser spot LS is heated by the small thermal energy intensity in the center of the laser spot LS, and then heated again by the large thermal energy intensity in the rear end of the laser spot LS.

In this way, after the surface of the mother glass substrate 50 is heated with a large thermal energy intensity, its heat is surely conducted to the inside while it is heated with a small thermal energy intensity. In addition, at this time, the surface of the mother glass substrate 50 is prevented from being continuously heated by a large thermal energy intensity, so that the softening of the surface of the mother glass substrate 50 can be prevented. Thereafter, when the mother glass substrate 50 is heated again with a large thermal energy intensity, the inside of the mother glass substrate 50 is surely heated, and compressive stress is generated on the surface and inside of the mother glass substrate 50 . Tensile stress is generated by spraying a cooling medium on cooling point CP near the region where such compressive stress is generated.

If compressive stress is generated on the heating area formed by the laser spot LS, and tensile stress is produced on the cooling point CP formed by the cooling medium, then the thermal diffusion area generated between the laser point LS and the cooling point CP The compressive stress generates a large tensile stress in the region opposite to the laser spot LS with respect to the cooling point CP. Utilizing this tensile stress, hidden cracks are generated along the planned scribing line starting from the notch TR formed in advance at the end of the mother glass substrate 50 .

If a concealed crack BC as a scratch line is formed on the mother glass substrate 50, the mother glass substrate 50 is supplied to the next cutting process, and a force is applied to the mother glass substrate 50 on both sides of the concealed crack BC to cause the concealed crack to occur. Bending moment at which the crack BC extends in the thickness direction of the mother glass substrate 50 . As a result, the mother glass substrate 50 is cut along the hidden crack BC formed along the planned scribe line SL.

In such a scribing apparatus, the thermal energy intensity distribution of the laser spot LS formed on the surface of the mother glass substrate 50 is such that the thermal energy intensity is maximized in the long-axis direction. In this way, the heat energy intensity is greatest at each end in the long-axis direction, and the surface of the mother glass substrate 50 is heated in two stages, whereby the mother glass substrate 50 is in a state where heat has been transferred to the inside of the substrate. Therefore, only by cooling with the refrigerant forming the cooling point CP, a sufficient thermal stress gradient cannot be obtained between the cooling point CP and deep hidden cracks (vertical cracks) cannot be formed. Therefore, there is a possibility that a cutting failure of the mother glass substrate 50 may occur in the aforementioned cutting step.

In such a case, the relative movement speed between the mother glass substrate 50 and the laser spot LS must be slowed down, and the heating time by the edge of the laser spot LS must be prolonged. As a result, the blind crack BC may not be efficiently formed.

The present invention was made to solve the above problems, and an object of the present invention is to provide a scribing method and a scribing device for a brittle material substrate capable of efficiently and reliably forming scribe lines on a brittle material substrate such as a mother glass substrate.

Contents of the invention

The scribing method of the brittle material substrate of the present invention continuously irradiates and moves the laser beam along the planned scribing line on the surface of the brittle material substrate to form a laser spot whose temperature is lower than the softening point of the brittle material substrate Cooling the area around the rear of the laser spot along the planned scribing line through the cooling medium, thereby forming a main cooling point, and continuously forming hidden cracks along the planned scribing line, characterized in that, compared with the main cooling point The cooling point is closer to the laser spot, and at least one auxiliary cooling point for cooling the area along the line to be scribed in advance with a refrigerant is formed while scribing is performed.

The auxiliary cooling point is formed using a refrigerant whose cooling temperature is higher than that of the main cooling point.

Also, the scribing device for a brittle material substrate according to the present invention includes: a laser beam irradiation mechanism that moves while continuously irradiating a laser beam so as to form a laser beam at a temperature lower than the softening point of the brittle material substrate on the surface of the brittle material substrate. The laser spot; the main cooling mechanism, through the cooling medium, continuously cools the vicinity of the area along the planned scribing line behind the area heated by the laser spot; forms hidden cracks along the planned scribing line on the surface of the brittle material substrate , which is characterized in that it has at least one auxiliary cooling mechanism, which uses a refrigerant whose temperature is higher than that of the main cooling mechanism to cool the laser beam formed by the aforementioned laser beam irradiation mechanism closer to the area cooled by the main cooling mechanism. Click the area on one side.

Description of drawings

FIG. 1 is a plan view schematically showing an implementation state of the scribing method of the present invention.

Fig. 2 is a front view showing an example of an embodiment of the scribing device of the present invention.

FIG. 3 is a graph showing the results of blind cracks formed in Example 1. FIG.

FIG. 4 is a graph showing the results of blind cracks formed in Example 2. FIG.

FIG. 5 is a graph showing the results of blind cracks formed in Example 3. FIG.

FIG. 6 is a graph showing the results of blind cracks formed in Example 4. FIG.

Fig. 7 is a plan view schematically showing another embodiment of the present invention.

FIG. 8 is a schematic diagram for explaining the operation of a conventional laser scribing device using a laser beam.

Fig. 9 is a perspective view schematically showing a state of formation of hidden cracks on a mother glass substrate scribed by the laser scribing device.

Fig. 10 is a plan view schematically showing a state of physical change on a mother glass substrate scribed by the laser scribing device.

Detailed ways

FIG. 1 is a schematic plan view of the surface of a mother glass substrate schematically showing the implementation state of the scribing method for a brittle material substrate according to the present invention. This scribing method is implemented for the following purposes: For example, when cutting a mother glass substrate to form a plurality of glass substrates constituting FPDs such as liquid crystal display panels, before cutting the mother glass substrate, forming a scribe line on the mother glass substrate. Hidden cracks with trace lines.

As shown in FIG. 1 , on the surface of the mother glass substrate 50 , a laser spot LS1 is formed by irradiation of a laser beam along the planned scribing line SL. In addition, on the side edge portion of the mother glass substrate 50 near the scribing start position of the planned scribing line SL on the surface of the mother glass substrate 50, a notch (fracture) TR along the planned scribing line SL is formed in advance. .

The laser spot LS1 has an elliptical shape and relatively moves in the direction indicated by the arrow A with respect to the surface of the mother glass substrate 50 with the major axis along the planned scribing line SL.

In this case, the thermal energy intensity of the laser spot LS1 formed on the mother glass substrate 50 is greater in the outer peripheral portion than in the central portion. Such a laser spot LS1 forms a laser beam having a Gaussian distribution of thermal energy intensity, that is, a thermal energy distribution such that the thermal energy intensity is maximized at each end portion in the major axis direction. Therefore, on each end portion in the long-axis direction on the planned scribing line SL, the heat energy intensity is respectively the maximum, and the heat energy intensity of the central portion of the laser spot LS1 sandwiched between each end portion is higher than that of each end portion. The thermal energy intensity is smaller.

The elliptical laser spot LS1 moves along the planned scribing line SL on the surface of the mother glass substrate 50 , and sequentially heats the planned scribing line SL.

The laser spot LS1 heats the mother glass substrate 50 while moving at a high speed relative to the mother glass substrate 50 at a temperature lower than the softening point temperature at which the mother glass substrate 50 softens. Thereby, the surface of the mother glass substrate 50 on which the laser spot LS1 is formed is heated without melting.

On the surface of mother glass substrate 50 , main cooling point MCP is formed behind the traveling direction of laser spot LS1 . The main cooling point MCP is formed by spraying cooling water, a mixed fluid of water and compressed air, a cooling medium such as compressed air, helium, nitrogen, carbon dioxide gas, etc. from the cooling nozzle to the surface of the mother glass substrate 50, thereby cooling the mother glass The surface of the substrate 50 is cooled; with respect to the mother glass substrate 50 in the same direction as the laser spot LS1, and at a speed equal to the moving speed of the laser spot LS1, along the scribing predetermined line on the surface of the mother glass substrate 50 SL mobile.

Further, on the surface of the mother glass substrate 50 , an auxiliary cooling point ACP close to the main cooling point MCP is formed along the scribing line SL in front of the main cooling point MCP in the advancing direction. The auxiliary cooling point ACP is formed by spraying cooling water, a mixed fluid of water and compressed air, a cooling medium such as compressed air, helium, nitrogen, carbon dioxide gas, etc. The temperature of the refrigerant on the point ACP is higher than the temperature of the refrigerant sprayed on the main cooling point MCP, and the surface of the mother glass substrate 50 is cooled in this state. The auxiliary cooling point ACP is also the same as the main cooling point MCP, with respect to the mother glass substrate 50 in the same direction as the laser spot LS1, and at a speed equal to the moving speed of the laser spot LS1, along the direction of the mother glass substrate 50. The planned scribing line SL on the surface moves.

After the surface of the mother glass substrate 50 is sequentially heated by the laser spot LS1 along the planned scribing line SL, the heated portion is cooled by the refrigerant forming the auxiliary cooling point ACP before being cooled by the refrigerant forming the main cooling point MCP. The cooling point MCP is cooled at a cooling temperature higher than that of the cooling point MCP, and then cooled to a temperature lower than that of the auxiliary cooling point ACP by passing through the refrigerant forming the main cooling point MCP.

When the mother glass substrate 50 is heated by the laser spot LS1, compressive stress is generated on the surface thereof, and thereafter, after being cooled once by the refrigerant forming the auxiliary cooling point ACP, it is cooled by the refrigerant forming the main cooling point MCP. Cool further. As a result, along the line to be scribed, lines of blind cracks BC that become deeper in the vertical direction are formed.

After the surface of the mother glass substrate 50 is heated by the laser spot LS1 to generate compressive stress, the surface of the mother glass substrate 50 is once cooled by the coolant forming the auxiliary cooling point ACP, thereby generating tensile stress. In the state where such tensile stress has been generated, if further cooling is performed by the refrigerant forming the main cooling point MCP, the surface of the mother glass substrate 50 is in a state where the tensile stress has been generated, so by forming the main cooling point Tensile stress generated by the cooling of the MCP refrigerant tends to act on the surface of the mother glass substrate 50 , forming deep hidden cracks BC in the vertical direction on the mother glass substrate 50 .

Also, in the scribing method by laser of the prior art shown in FIG. , so in addition to the formation of hidden cracks, a useless thermal shock is produced.

In the scribing method of the present invention, by setting the auxiliary cooling point ACP between the main cooling point MCP and the laser point LS1, the above-mentioned useless thermal shock can be alleviated, and the energy lost by the thermal shock can be used to elongate the hidden crack. force.

If a hidden crack as a scratch line is formed on the mother glass substrate 50, the mother glass substrate 50 is supplied to the next cutting process, and a force is applied to the mother glass substrate 50 on both sides of the hidden crack so that the hidden crack is generated along the Bending moment stretched in the thickness direction of the mother glass substrate 50 . As a result, the mother glass substrate 50 is cut along the hidden crack formed along the planned scribing line SL.

Fig. 2 is a schematic configuration diagram showing an embodiment of a scribing device for a brittle material substrate according to the present invention. The scribing device of the present invention is, for example, a device for forming a scribe line for cutting the mother glass substrate 50 into a plurality of glass substrates used for FPDs. As shown in FIG. 2 , this scribing device has a slide table 12 that reciprocates in a predetermined horizontal direction (Y direction) on a horizontal stand 11 .

The slide table 12 is supported in a horizontal state so as to be slidable along respective guide rails 14 and 15 arranged parallel to the Y direction on the upper surface of the stand 11 . A lead screw 13 is provided in parallel to each guide rail 14 and 15 so as to be rotated by a motor (not shown) at an intermediate portion of both guide rails 14 and 15 . The lead screw 13 can rotate forward and reverse, and the ball nut 16 is installed on the lead screw 13 in a screwed state. The ball nut 16 is integrally attached to the slide table 12 in a non-rotating state, and slides along the lead screw 13 in two directions by forward rotation and reverse rotation of the lead screw 13 . Thereby, the slide table 12 to which the ball nut 16 is integrally attached slides in the Y direction along each guide rail 14 and 15 .

The pedestal 19 is arranged on the slide table 12 in a horizontal state. The pedestal 19 is slidably supported on a pair of guide rails 21 arranged in parallel on the slide table 12 . Each guide rail 21 is arranged along the X direction perpendicular to the Y direction which is the sliding direction of the slide table 12 . In addition, a lead screw 22 is disposed parallel to each guide rail 21 at the center between the guide rails 21 , and the lead screw 22 can be rotated forward or backward by a motor 23 .

The ball nut 24 is mounted on the lead screw 22 in a screwed state. The ball nut 24 is integrally attached to the pedestal 19 in a non-rotating state, and moves in two directions along the screw 22 by forward rotation and reverse rotation of the screw 22 . Accordingly, the pedestal 19 slides in the X direction along each guide rail 21 .

A rotation mechanism 25 is provided on the pedestal 19 , and a rotation table 26 on which the mother glass substrate 50 to be cut is placed is installed in a horizontal state on the rotation mechanism 25 . The rotation mechanism 25 rotates the rotation table 26 around a central axis along the vertical direction, and can rotate the rotation table 26 to an arbitrary rotation angle θ from the reference position. The mother glass substrate 50 is fixed to the turntable 26 by, for example, a suction chuck.

The support stand 31 is disposed above the turntable 26 with an appropriate interval therebetween. The support stand 31 is supported in a horizontal state by the lower end portion of an optical holder 33 arranged in a vertical state. The upper end of the optical holder 33 is attached to the lower surface of the mount 32 provided on the stand 11 . A laser oscillator 34 for oscillating a laser beam is provided on the mount 32 , and the laser beam oscillated by the laser oscillator 34 is irradiated to an optical system held in an optical holder 33 .

The laser beam that oscillates and produces from the laser oscillator 34, its heat energy intensity distribution is a normal distribution, passes through the optical system that is arranged in the optical support 33, forms the laser spot LS1 of ellipse shape as shown in Figure 1, and, with its The long-axis direction is irradiated onto the mother glass substrate 50 mounted on the turntable 26 so that it is parallel to the X direction which is the moving direction of the turntable 26 .

The auxiliary cooling nozzle 41 is disposed on the support table 31 with an appropriate interval between the optical mount 33 and the mother glass substrate 50 mounted on the turntable 26 . The auxiliary cooling nozzle 41 sprays a cooling medium such as cooling water, a mixed fluid of water and compressed air, compressed air, helium, etc., onto the laser spot LS1 formed on the mother glass substrate by the laser beam irradiated from the optical holder 33. rear position.

Moreover, the main cooling nozzle 37 is arrange|positioned at the space|interval of 4 mm or more from this auxiliary cooling nozzle 41 on the support base 31. As shown in FIG. The main cooling nozzle 37 sprays a cooling medium such as cooling water, a mixed fluid of water and compressed air, compressed air, or helium gas to a position behind the mother glass substrate cooled by the auxiliary cooling nozzle 41 . The cooling temperature of the cooling medium sprayed onto the mother glass substrate 50 from the main cooling nozzles 37 is lower than that of the cooling medium blown onto the mother glass substrate 50 from the auxiliary cooling nozzles 41 .

In addition, on the support table 31, a cutter wheel is provided on the side opposite to the main cooling nozzle 37 with respect to the laser spot LS1 irradiated from the optical holder 33, so as to face the mother glass substrate 50 placed on the rotary table 26. 35. The cutter wheel 35 is arranged along the long axis direction of the laser spot LS1 irradiated from the optical holder 33, and forms a cut along the direction of the planned scribing line on the side edge of the mother glass substrate 50 placed on the rotary table 26 ( broken seam).

In addition, the positioning of the slide table 12 and the base 19, the rotation mechanism 25, the laser oscillator 34, and the like are controlled by a control unit (not shown).

When forming hidden cracks on the surface of the mother glass substrate 50 by such a scribing device, first, information such as the size of the mother glass substrate 50 and the position of the planned scribing line is input to the control unit.

Then, mother glass substrate 50 is placed on turntable 26 and fixed by a suction mechanism. When such a state is reached, the alignment marks provided on the mother glass substrate 50 are imaged by the CCD cameras 38 and 39 . The imaged alignment marks are displayed on the monitors 28 and 29 , and the positional information of the alignment marks on the mother glass substrate 50 is processed in the image processing device.

When the rotary table 26 is positioned relative to the support table 31 , the rotary table 26 slides in the X direction, and the planned scribing line on the side edge of the mother glass substrate 50 faces the cutter wheel 35 . Then, the cutter wheel 35 descends to form a notch (fracture) TR on the side edge of the mother glass substrate 50 along the planned scribing line.

Thereafter, while the rotary table 26 slides in the X direction along the line to be scribed, the laser beam is oscillated from the laser oscillator 34, and a cooling medium such as cooling water is sprayed from the auxiliary cooling nozzle 41, and the main cooling nozzle 37 Cooling water, etc. are ejected together with compressed air.

The laser beam oscillated by the laser oscillator 34 forms an elliptical laser spot LS1 elongated in the X-axis direction on the mother glass substrate 50 along the scanning direction of the mother glass substrate 50 . Then, at the rear of the laser spot LS1 , a cooling medium is sprayed from the auxiliary cooling nozzle 41 along the planned scribing line to form an auxiliary cooling point ACP. Further, at the rear of the auxiliary cooling point ACP, the cooling medium is sprayed from the main cooling nozzle 37 along the planned scribing line to form the main cooling point MCP.

Thus, as mentioned above, if the laser spot LS1 is used for heating, the stress gradient formed by the cooling of the auxiliary cooling point ACP and the main cooling point MCP is smaller than that of the conventional situation where the auxiliary cooling point ACP is not used. Vertical hidden cracks are formed deeper on the mother glass substrate 50 .

When a hidden crack is formed on the mother glass substrate 50, the mother glass substrate 50 is supplied to the next cutting process, and a force is applied to the mother glass substrate so that a bending moment acts on the width direction of the hidden crack. As a result, the mother glass substrate 50 is cut along the hidden crack from the notch TR provided at the side edge.

In addition, in the description of the above embodiment, although the main cooling point MCP and the auxiliary cooling point ACP are formed by directly spraying the cooling medium from the main cooling nozzle 37 and the auxiliary cooling nozzle 45 onto the scribing line SL, it is preferable For example, it has a mechanism for moving the main cooling nozzle 37 and the auxiliary cooling nozzle 45 independently in the X direction and the Y direction, and can freely adjust the distance between the laser spot LS1 and the auxiliary cooling point ACP on the planned scribing line and The distance between the auxiliary cooling point ACP and the main cooling point MCP, or the positions of the auxiliary cooling point ACP and the main cooling point MCP are set to shift positions on the scribe line.

In addition, in the embodiment of the present invention, although the mother glass substrate of the liquid crystal display panel is used as an example of a brittle material substrate, the present invention is also applicable to bonding glass substrates, single-plate glass, semiconductor wafers, ceramics, etc. Scribing processing.

Also, in the above description, although the case where the thermal energy intensity of the outer peripheral edge of the laser spot LS1 formed on the mother glass substrate 50 is greater than the thermal energy intensity of the central portion has been described, the thermal energy of the laser spot LS1 The energy distribution may be a Gaussian distribution.

(Example)

Next, examples in which hidden cracks are formed on glass substrates under various conditions using this scribing apparatus will be described.

(Example 1)

The laser beam oscillated by the laser oscillator 34 was set at 200 W, and was irradiated on the soda lime glass substrate with a thickness of 3.0 mm to form hidden cracks. The laser spot LS1 formed on the glass substrate has, for example, an elliptical shape with a major axis of 40 mm and a minor axis of 1.5 mm, and the main cooling spot MCP formed by cooling medium sprayed from the main cooling nozzle 37 is formed at a position 85 mm from the center of the laser spot LS1 Also, the auxiliary cooling spot ACP formed by the refrigerant sprayed from the auxiliary cooling nozzle 41 is formed at a position on the laser spot LS1 side away from the main cooling point MCP by 10 mm.

A nozzle with a tip inner diameter of 0.6 mm was used as the main cooling nozzle 37 , and a nozzle with a tip inner diameter of 0.8 mm was used as the auxiliary cooling nozzle 41 .

A mixed fluid of water and compressed air was sprayed at a pressure of 0.5 MPa (flow rate: 10 L/min) from the main cooling nozzle 37 at a height of 5 mm from the surface of the glass substrate. In addition, compressed air was injected at a pressure of 0.2 MPa (flow rate: 14 L/min) from the auxiliary cooling nozzle 41 at a height of 1 mm from the surface of the glass substrate. Furthermore, the moving speed of the glass substrate was changed stepwise in units of 10 mm/s from 100 mm/s to 180 mm/s, a hidden crack was formed on the glass substrate, and its depth δ was measured. The result is shown in Figure 3. In addition, for ease of comparison, the depth δ of the hidden crack when the auxiliary cooling point ACP is not formed by the auxiliary cooling nozzle 41 is also indicated in FIG. 3 .

In this case, by forming the auxiliary cooling point ACP by the auxiliary cooling nozzle 41, the depth δ of the hidden crack becomes deeper by about 10% compared to the case where the auxiliary cooling point ACP is not formed.

(Example 2)

The glass substrate was a soda lime glass substrate with a thickness of 1.1 mm, and a mixed fluid of water and compressed air was sprayed from the main cooling nozzle 37 at a pressure of 0.5 MPa (flow rate: 10 L/min). Also, compressed air is injected from the auxiliary cooling nozzle 41 at a pressure of 0.2 MPa (flow rate: 14 L/min), and furthermore, the auxiliary cooling nozzle 41 is arranged at a distance of 7 mm from the main cooling nozzle 37 . The moving speed of the glass substrate was changed stepwise in units of 20 mm/s from 100 mm/s to 400 mm/s, and hidden cracks were formed on the glass substrate, and the depth δ thereof was measured. The result is shown in Figure 4. In addition, for the sake of comparison, the depth δ of the hidden crack when the auxiliary cooling point ACP is not formed by the auxiliary cooling nozzle 41 is also indicated in FIG. 4 .

In addition, other implementation conditions are the same as in Example 1.

In this case, by forming the auxiliary cooling point ACP by the auxiliary cooling nozzle 41, the depth δ of the hidden crack becomes deeper by about 10% compared to the case where the auxiliary cooling point ACP is not formed.

(Example 3)

The position of the auxiliary cooling point ACP formed by the auxiliary cooling nozzle 41 is changed between 0 mm and 15 mm relative to the position of the main cooling point MCP formed by the main cooling nozzle 37, and the pressure when the cooling medium is injected through the auxiliary cooling nozzle 41 is between 0 mm and 15 mm. 0.1Mpa (flow rate: 7L/min), 0.2Mpa (flow rate: 14L/min) and 0.3Mpa (flow rate: 21L/min) change between the three, and the conditions other than this are the same as in Example 1, thus forming Conceal the crack and measure its depth δ. The result is shown in Figure 5.

In this case, the distance between the auxiliary cooling nozzle 41 and the main cooling nozzle 37 is about 10 mm, and the auxiliary cooling point ACP is formed on the glass substrate, thereby, compared with the case where the auxiliary cooling point ACP is not formed, The depth δ of hidden cracks deepens by about 10%.

(Example 4)

The distance between the auxiliary cooling point ACP formed by the auxiliary cooling nozzle 41 and the main cooling point MCP formed by the main cooling nozzle 37 is changed between 5 mm and 9 mm, and the pressure when the cooling medium is injected through the auxiliary cooling nozzle 41 is 0.1 Mpa (flow rate: 7L/min), 0.2Mpa (flow rate: 14L/min) and 0.3Mpa (flow rate: 21L/min) vary among the three, except that the conditions are the same as in Example 2, thus forming a concealed Crack, measure its depth δ. The result is shown in Figure 6.

In this case, the distance between the auxiliary cooling nozzle 41 and the main cooling nozzle 37 is about 7 mm, and the auxiliary cooling point ACP is also formed on the glass substrate. , the depth δ of hidden cracks deepens by about 10%.

Fig. 7 is a plan view schematically showing another embodiment of the present invention. The laser beam oscillated by the laser oscillator 34 forms an elliptical laser spot LS1 elongated in the X-axis direction on the mother glass substrate 50 along the scanning direction of the mother glass substrate 50 . Then, behind the laser spot LS1, a cooling medium is sprayed from the plurality of auxiliary cooling nozzles 41 along the planned scribing line to form a plurality of auxiliary cooling points ACP. Furthermore, at the rear of the plurality of auxiliary cooling points ACP, the cooling medium is sprayed from the main cooling nozzle 37 along the planned scribing line SL to form the main cooling points MCP.

After the surface of the mother glass substrate 50 is sequentially heated by the laser spot LS1 along the planned scribing line SL, the heated part passes through a plurality of auxiliary cooling points ACP in turn to form a main cooling point before being cooled by the main cooling point MCP. The refrigerant at the point MCP is cooled at a temperature higher than that of the refrigerant forming the auxiliary cooling point ACP.

When mother glass substrate 50 is heated by laser spot LS1 , compressive stress is generated on the surface, and thereafter, after being once cooled by a plurality of auxiliary cooling points ACP, it is further cooled by main cooling point MCP. As a result, along the line to be scribed, lines that conceal cracks that become deeper in the vertical direction are formed.

Also, in the scribing method performed by laser in the prior art shown in FIG. , so in addition to the formation of hidden cracks, a useless thermal shock is produced.

By arranging a plurality of auxiliary cooling points ACP on the side closer to the laser point LS1 than the main cooling point MCP, the above-mentioned useless thermal shock can be alleviated, and the energy lost by the thermal shock can be used to elongate the hidden crack. One auxiliary cooling point can cool the mother glass substrate sequentially without unnecessary thermal shock, and can form deeper hidden cracks (vertical cracks) than when there is one auxiliary cooling point.

Because the cooling medium for forming the main cooling point and the auxiliary cooling point on the glass substrate is the same as that of forming the aforementioned auxiliary cooling point on the mother glass substrate, it will not be described in detail here.

Also, as the configuration of the scribing device, it is preferable to have a mechanism for moving the main cooling nozzle 37 and the plurality of auxiliary cooling nozzles 41 independently in the X direction and the Y direction, for example, so that they can be freely adjusted on the planned scribing line. The distance between the laser spot LS1 and the auxiliary cooling point ACP on the side closest to the laser spot, the distance between the auxiliary cooling point ACP on the side closest to the main cooling point MCP and the main cooling point MCP, and the distance between multiple auxiliary cooling points , and furthermore, the positions of the plurality of auxiliary cooling points ACP and the main cooling point MCP are set to be shifted on the scribing line.

In this way, the present invention is realized by arranging at least one auxiliary cooling point between the laser spot and the main cooling point on the mother glass substrate.

Industrial Applicability

In this way, the scribing method and scribing device for a brittle material substrate of the present invention are formed between the laser spot and the main cooling point formed on the surface of a brittle material substrate such as a mother glass substrate, at a position close to the main cooling point. Since the cooling point is assisted, hidden cracks can be formed deeply, and therefore, hidden cracks can be formed efficiently.

Claims (3)

1. the scribble method of a brittle substrate, lip-deep line preset lines along brittle substrate, illuminating laser beam and moving it continuously, with the formation temperature laser point lower than the softening point of this brittle substrate, by near cooling medium the zone of line preset lines, cooling off to the rear of this laser point, thereby form main cooling point, form hidden crackle continuously along the line preset lines

It is characterized in that, in a side than the more close laser point of described main cooling point, Yi Bian be formed in advance at least one that cool off along the zone of line preset lines being assisted cooling point by refrigerant, Yi Bian rule.

2. the scribble method of brittle substrate as claimed in claim 1, aforementioned auxiliary cooling point utilize chilling temperature, and the refrigerant higher than the chilling temperature of the refrigerant that forms aforementioned main cooling point forms.

3. the chalker of a brittle substrate possesses: the laser beam irradiation means, and meanwhile continuously illuminating laser beam move it, with the laser point lower of formation temperature on the surface of this brittle substrate than the softening point of brittle substrate;

Main cooling body utilizes refrigerant near cooling off continuously the zone of line preset lines by this laser point area heated rear; Lip-deep line preset lines along brittle substrate forms hidden crackle, it is characterized in that,

Have at least one auxiliary cooling body, it utilizes the temperature refrigerant higher than the temperature of the refrigerant of above-mentioned main cooling body, and cooling raio is by the above-mentioned main cooling body institute more close zone by formed laser point one side of aforementioned laser bundle irradiation means of cooled zones.

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