KR100649894B1 - Method and device for scribing fragile material substrate - Google Patents

Abstract

Along the scribe line SL on the surface of the mother glass substrate 50, the laser beam is continuously irradiated to form a laser spot LS at a temperature lower than the mother glass softening point, while the area near the scribe line SL is swept along the scribe line SL. By cooling, the main cooling spot MCP is formed to continuously form cracks along the scribe scheduled line SL. In this case, an assist cooling spot ACP is formed on the laser spot LS side rather than the main cooling spot MCP, which cools the area along the scribe line SL close to the main cooling spot MCP in advance.

Description

Scribing method and scribing apparatus of a brittle material substrate {METHOD AND DEVICE FOR SCRIBING FRAGILE MATERIAL SUBSTRATE}             

The present invention is brittle in order to cut brittle material substrates such as glass substrates, semiconductor wafers and the like used in flat panel displays (hereinafter referred to as flat panel displays). A scribe method and scribe device for forming a scribe line on a surface of a material substrate.

Hereinafter, the prior art in the case of forming a scribe line on a glass substrate, which is a type of brittle material substrate used for various flat panel displays, or a mother brittle material substrate formed by bonding the brittle material substrate to each other, is formed. Explain.

A pair of glass substrates bonded (接合) by FPD such as a liquid crystal display panel (液晶表示panel) consisting of the pair of mother glass substrate (mother glass基板) to the respective mother glass substrate FPD to each other after joined together It cuts so that it may become a glass substrate of the predetermined magnitude | size which comprises. Each mother glass substrate is cut along the scribe line after a scribe line is formed by a cutter made of diamond in advance. Also be due to the difference of the flat panel display type and the production method of forming a scribe line on the mother glass substrate before bonding when cutting the mother glass substrate.

When a scribe line is mechanically formed by a cutter or the like, the peripheral portion of the formed scribe line is in a state where residual stress is accumulated. When the mother glass substrate is cut along the scribe line, the residual stress is accumulated at the edge portion and the peripheral portion of the edge of the surface of the glass substrate to be cut and formed. This residual stress is a potential stress that causes an unnecessary crack to be extended near the surface of the glass substrate. When the residual stress is released, unnecessary cracks are generated and the cut surface of the glass substrate is removed. There is a risk of breakage of the edges. Debris generated by breaking the edge portion of the cut surface of the glass substrate may adversely affect the produced FPD.

Recently, a method of using a laser beam has been put into practical use to form a scribe line on the surface of a mother glass substrate. In the method of forming a scribe line on the mother glass substrate using a laser beam, the laser beam LB is irradiated from the laser oscillator 61 on the mother glass substrate 50 as shown in FIG. . Laser beam emitted from the laser oscillation device 61 is LB, to form a bonded mother glass substrate 50 on the planned scribing line (scribe line豫定) the laser spot on the oval along the SL (laser spot) LS on the surface of the mother glass substrate 50. The laser beam LB irradiated from the mother glass substrate 50 and the laser oscillation device 61 is relatively moved along the longitudinal direction of the laser spot LS.

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

In the vicinity of the irradiation area of the laser beam LB on the surface of the mother glass substrate 50, a cooling medium such as cooling water is provided with a cooling nozzle 62 so that a scribe line is formed. It is to be injected from the. On the surface of the mother glass substrate 50 to which the laser beam LB is irradiated, compressive stress is generated by heating with the laser beam LB, and a tensile stress is generated by ejecting a cooling medium. As the tensile stress is generated in the region close to the region where the compressive stress is generated in this way, a stress gradient based on the respective stresses is generated between the two regions, and the mother glass substrate 50 has an end portion of the mother glass substrate 50 ( Vertical cracks are formed in the thickness direction (vertical direction) of the mother glass substrate 50 along the scribe planned line SL from the cut-off TR previously formed in the back part. In other words, this vertical crack line is a scribe line.

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

FIG. 9 is a schematic perspective view showing the formation of blind cracks BC on a mother glass substrate 50 scribed by a laser scribe device, and FIG. 10 is a diagram schematically illustrating a physical change state on the mother glass substrate 50. It is a top view showing.

The laser beam oscillated from the laser oscillation device 61 forms an elliptical laser spot LS on the surface of the mother glass substrate 50. The laser spot LS is irradiated so that a long axis may correspond with the scribe scheduled line SL.

In this case, the laser spot LS formed on the mother glass substrate 50 is such that the thermal energy intensity of the outer circumferential edge portion is larger than the thermal energy intensity of the central portion. Such a laser spot LS is formed by making the laser beam whose heat energy intensity is Gaussian distribution into the heat energy distribution in which each edge part of a long axis direction becomes the maximum heat energy intensity. Therefore, at each end portion in the long axis direction positioned on the scribe line SL, the heat energy intensity is maximized, respectively, and the heat energy intensity at the center portion of the laser spot LS inserted between the ends is smaller than the heat energy intensity at each end portion. It is meant to be built.

The mother glass substrate 50 is relatively moved along the major axis direction of the laser spot LS. Therefore, the mother glass substrate 50 is a large thermal energy at one end of the major axis direction of the laser spot LS along the scheduled scribe line SL. After being heated to the intensity, it is heated to a small thermal energy intensity at the center of the laser spot LS and thereafter to a large thermal energy intensity. Thereafter, the cooling medium is injected from the cooling nozzle 62 to the cooling point CP on the scribe line at a predetermined distance L, for example, from the rear end of the laser spot LS.

As a result, a temperature gradient occurs between the laser spot LS and the cooling point CP, and a large tensile stress is generated in the region on the side opposite to the laser spot LS with respect to the cooling point CP. And by using the tensile stress along the planned scribing line TR from the notches formed at an end of the mother glass substrate 50 in the direction of the thickness t of the mother glass substrate 50 it is formed with a vertical crack.

The mother glass substrate 50 is heated by an elliptical laser spot LS. In this case, the mother glass substrate 50 is three-dimensionally transferred heat from the surface toward the inside by the large thermal energy intensity at one end of the laser spot LS, but the laser spot LS is relative to the mother glass substrate 50. The portion heated by the front end of the laser spot LS by being moved to the front end of the laser spot LS is heated by the small thermal energy intensity at the center of the laser spot LS, and then again at the rear end of the laser spot LS. It is heated by a large thermal energy intensity of.

In this way, the surface of the mother glass substrate 50 is heated by a large thermal energy intensity and then the heat is surely conducted to the inside while being heated by 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, and the softening of the surface of the mother glass substrate 50 is prevented. Once again after the thermal energy by the larger strength the mother glass substrate 50 is heated, the mother glass substrate 50 is being heated inside reliably generating a compressive stress (壓縮應力) on the surface and inside of the mother glass substrate 50 to the. The tensile stress is generated by spraying the cooling medium on the cooling point CP near the region where the compressive stress is generated.

When compressive stress is generated in the heating area by the laser spot LS and tensile stress is generated in the cooling point CP by the cooling medium, the compression is generated in the thermal diffusion region between the laser spot LS and the cooling point CP. Due to the stress, a large tensile stress is generated in the region opposite to the laser spot LS with respect to the cooling point CP. Using this tensile stress, a blind crack is generated along the scribe scheduled line from the cut TR formed at the end of the mother glass substrate 50.

When the blind crack BC as a scribe line formed on the mother glass substrate 50 the mother glass substrate 50 is fed to the next cutting step of the bending moment to diffuse in the thickness direction of the blind crack BC on both sides of the blind crack BC mother glass substrate 50 ( A force is applied to the mother glass substrate 50 so that a bending moment occurs. As a result, the mother glass substrate 50 is cut along the blind crack BC formed along the scribe scheduled line SL.

In such a scribe device, the laser spot LS formed on the surface of the mother glass substrate 50 has a heat energy intensity distribution in which the heat energy intensity is maximized in the major axis direction. Thus, there is a maximum intensity of thermal energy in each of the end portions in the major axis direction, by heating the surface of the mother glass substrate 50 in step two mother glass substrate 50 is a thermal heat transfer (轉熱) state in the substrate. For this reason, only cooling by the refrigerant | coolant which forms cooling point CP does not acquire sufficient thermal stress gradient between cooling point CP, and deep blind cracks (vertical cracks) are not formed. For this reason, there exists a possibility that the cutting | disconnection defect of the mother glass substrate 50 may arise in the said cutting process.

In this case, since the relative movement speed between the mother glass substrate 50 and the laser spot LS must be slowed down, the heating time by the end of the laser spot LS must be lengthened. As a result, the blind crack BC can be efficiently formed. There is a risk of missing.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object thereof is to provide a scribing method and a scribing apparatus for a brittle material substrate which can efficiently and reliably form a scribe line on a brittle material substrate such as a mother glass substrate.

The scribe method of the brittle material substrate of the present invention is lower than the softening point of the brittle material substrate along a scribe predetermined line on the surface of the brittle material substrate. The laser beam continuously irradiates and moves the laser beam so that a laser spot of temperature is formed, and a cooling medium moves around the area along the scribe line scheduled behind the laser spot. In the scribing method of a brittle material substrate in which a cooling spot is formed by cooling to continuously form a blind crack along a scribe scheduled line,

It is characterized by scribing at least one assist cooling spot for cooling the area along the scribe scheduled line by a refrigerant in advance as the laser spot side rather than the cooling spot.

The assist cooling spot is formed by a refrigerant having a cooling temperature higher than that of the refrigerant forming the cooling spot.

In addition, the scribing apparatus for the brittle material substrate of the present invention is a laser beam irradiation means for moving while continuously irradiating a laser beam so that a laser spot having a temperature lower than the softening point of the brittle material substrate is formed on the surface of the brittle material substrate. A scribe line on the surface of the brittle material substrate, having cooling means for continuously cooling the area near the region along the scribe line on the rear of the region heated by the laser spot with a refrigerant. In the scribing apparatus of a brittle material substrate which forms a blind crack along the surface, the area | region on the side of the laser spot formed by the said laser beam irradiation means rather than the area | region cooled by the cooling means has temperature higher than the temperature of the refrigerant | coolant of a cooling means. In the refrigerant of To open the cooling it characterized in that it comprises at least one cooling means, the assist (assist 冷却 手段).

1 is a schematic plan view showing an embodiment of a scribing method according to the present invention.

2 is a front view showing an example of an embodiment of a scribing apparatus according to the present invention.

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

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

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

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

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

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

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

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

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic plan view of a mother glass substrate surface schematically showing an embodiment of a scribe method for a brittle material substrate in the present invention. The scribing method is, for example, when forming the plurality of glass substrates (glass基板) constituting the FPD such as a mother cutting the glass substrate and the liquid crystal display panel (液晶表示panel), before cutting the mother glass substrate mother glass This is done to form blind cracks that become scribe lines on the substrate.

As shown in FIG. 1, a laser spot LS1 is formed on the surface of the mother glass substrate 50 by irradiation of a laser beam along a scribe predetermined line SL. . Also, the edge portions of the mother glass substrate 50 near the scribe start position of the planned scribing line SL, TR that follows the planned scribing line notches (cut line (cut line)) is formed in advance on the surface of the mother glass substrate 50 .

The laser spot LS1 has an elliptical shape and is relatively moved in the direction indicated by the arrow A with respect to the surface of the mother glass substrate 50 while the long diameter is along the scribe scheduled line SL.

In this case, the laser spot LS1 formed on the mother glass substrate 50 is such that the thermal energy intensity of the outer circumferential edge portion is greater than the thermal energy intensity of the central portion. Such a laser spot LS1 is formed by making the laser beam whose heat energy intensity is Gaussian distribution into the heat energy distribution which each edge part of a major axis direction becomes the maximum heat energy intensity. Therefore, at each end portion in the major axis direction positioned on the scribe line SL, the heat energy intensity is maximized, respectively, and the heat energy intensity at the center portion of the laser spot LS1 inserted between the ends is smaller than the heat energy intensity at each end portion. It is meant to be built.

The elliptical laser spot LS1 moves along the scribe scheduled line SL on the surface of the mother glass substrate 50 to sequentially heat the scribe scheduled line SL.

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

On the surface of the mother glass substrate 50, the main cooling point MCP is formed in the rear of the advancing direction of the laser spot LS1. The main cooling point MCP includes a mixture of cooling water, water and compressed air, compressed air, He gas and N ₂ from the cooling nozzle on the surface of the mother glass substrate 50. It is formed so as to cool the surface of the mother glass substrate 50 by spraying a cooling medium such as gas, CO ₂ gas, and the like in the same direction as the laser spot LS1 for the mother glass substrate 50. It is moved along the scribe scheduled line SL of the surface of the mother glass substrate 50 at the same speed as the movement speed.

On the surface of the mother glass substrate 50, an assist cooling point ACP is formed along the scribe scheduled line SL near the main cooling point MCP in front of the main cooling point MCP. Assist cooling point ACP is a mother glass substrate 50 by spraying a cooling medium, such as cooling water, mixed fluid of water and compressed air, compressed air, He gas, N ₂ gas, CO ₂ gas from the cooling nozzle to the surface of the mother glass substrate 50 The surface of is cooled in the state where the temperature of the refrigerant injected to the assist cooling point ACP is higher than the temperature of the refrigerant injected to the main cooling point MCP. Assist cooling point ACP is also moved along the main cooling point MCP as with the planned scribing line of the mother glass substrate to 50 the same direction as the laser spot LS1 of the addition at the same speed as the moving speed of the laser spot LS1 mother glass substrate 50 surface SL .

The surface of the mother glass substrate 50 is sequentially heated by the laser spot LS1 along the scribe scheduled line SL, and then forms the assist cooling point ACP just before the heating portion is cooled by the refrigerant forming the main cooling point MCP. The refrigerant is cooled at a cooling temperature higher than the main cooling point MCP, and then the refrigerant forming the main cooling point MCP is cooled at a cooling temperature lower than the assist cooling point ACP.

When the mother glass substrate 50 is heated by the laser spot LS1, a compressive stress is generated on the surface thereof, and after that, the mother glass substrate 50 is once cooled by a refrigerant that forms the assist cooling point ACP, and then forms a main cooling point MCP. Is further cooled. As a result, a line of blind crack BC deepened vertically along the scribe line is formed.

After the surface of the mother glass substrate 50 is heated by the laser spot LS1 to generate a compressive stress, a tensile stress is generated by cooling the surface of the mother glass substrate 50 once with the refrigerant forming the assist cooling point ACP. . In the state where the tensile stress is generated, if the cooling is further performed by the refrigerant forming the main cooling point MCP, the surface of the mother glass substrate 50 is already in the state of tensile stress. so the tensile stress generated by the cooling tends to act on the surface of the mother glass substrate 50, the mother glass substrate 50 is considered to be formed with a deep blind crack BC in the vertical direction.

Further, in the scribing method using a laser in the prior art shown in Fig. 10, after cooling the surface of the mother glass substrate 50 by laser spot LS, a cooling medium is sprayed to cool the surface of the mother glass substrate 50. Therefore, it is considered that unnecessary thermal shock occurs after the formation of blind cracks.

In the scribing method of the present invention, the assist cooling point ACP is provided between the main cooling point MCP and the laser spot LS1 to alleviate the unnecessary thermal shock, and the energy lost by the thermal shock extends the blind crack. I think it is consumed.

When the blind crack as a scribe line formed on the mother glass substrate 50, the mother glass substrate 50 is supplied to the next cutting step of the bending moment of extending the blind crack on either side of the blind crack in the thickness direction of the mother glass substrate 50 (bending moment) A force is applied to the mother glass substrate 50 so as to generate. Accordingly, the mother glass substrate 50 is cut along the blind crack formed along the scribe line SL.

Fig. 2 is a schematic block diagram showing an embodiment of a scribing apparatus for a brittle material substrate in the present invention. The scribing apparatus of this invention is an apparatus which forms the scribe line for cutting into the several glass substrate used for FPD from the mother glass substrate 50, for example. This scribe apparatus is provided with the slide table 12 which reciprocates along a predetermined horizontal direction (Y direction) on the horizontal mounting base 11 as shown in FIG.

The slide table 12 can slide along the guide rails 14 and 15 in a horizontal state on a pair of guide rails 14 and 15 arranged in parallel in the Y direction on the upper surface of the mounting table 11. Is supported. In the middle part of both guide rails 14 and 15, the ball screw 13 is installed in parallel with each guide rail 14 and 15 so that it may rotate with a motor (not shown). The ball screw 13 is capable of forward rotation and reverse rotation, and a ball nut 16 is screwed into the ball screw 13. The ball nut 16 is integrally provided on the slide table 12 so as not to rotate, and slides in both directions along the ball screw 13 by forward and reverse rotation of the ball screw 13. As a result, the slide table 12 integrally provided with the ball nut 16 slides along the guide rails 14 and 15 in the Y direction.

On the slide table 12, the base 19 is arrange | positioned in the horizontal state. The base 19 is slidably supported by a pair of guide rails 21 arranged in parallel on the slide table 12. Each guide rail 21 is arrange | positioned along the X direction orthogonal to the Y direction which is the slide direction of the slide table 12. As shown in FIG. In addition, the ball screw 22 is arrange | positioned in parallel with each guide rail 21 in the center part between each guide rail 21, The ball screw 22 is made to perform forward rotation and reverse rotation by the motor 23. As shown in FIG.

The ball screw 22 is attached with the ball nut 24 screwed. The ball nut 24 is integrally installed on the pedestal 19 so as not to rotate, and moves in both directions along the ball screw 22 by the forward and reverse rotation of the ball screw 22. Accordingly, the pedestal 19 slides in the X direction along each guide rail 21.

On the base 19, a rotating mechanism 25 is provided, and on the rotating mechanism 25, a rotating table 26 on which the mother glass substrate 50 to be cut is placed is placed in a horizontal state. have. The rotary mechanism 25 is configured to rotate the rotary table 26 about the central axis along the vertical direction, and can rotate the rotary table 26 so as to have an arbitrary rotation angle θ with respect to the reference position. On the rotary table 26, a mother glass substrate 50 is fixed by, for example, a suction chuck.

Above the turntable 26, the support base 31 is arrange | positioned with the appropriate space | interval with the turntable 26. FIG. The support 31 is supported in a horizontal state at the lower end of the optical holder 33 arranged in a vertical state. The upper end of the optical holder 33 is attached to the lower surface of the mounting table 32 provided on the mounting table 11. On the mounting table 32, a laser oscillator 34 for oscillating a laser beam is provided, and a laser beam oscillating from the laser oscillator 34 is supported in the optical holder 33. Irradiated with an optical device.

The laser beam oscillated from the laser oscillator 34 has a regular distribution of thermal energy intensity and has an elliptical laser spot as shown in FIG. 1 by an optical device installed in the optical holder 33. It is irradiated with the mother glass substrate 50 mounted on the rotating table 26 so that it may become (laser spot) LS1 and its long axis direction may become parallel to the X direction which is the moving direction of the rotating table 26. As shown in FIG.

On the support base 31, an assist cooling nozzle 41 is disposed facing the mother glass substrate 50 placed on the rotary table 26 at an appropriate distance from the optical holder 33. As shown in FIG. The assist cooling nozzle 41 is a mixed fluid of cooling water, water and compressed air at a position rearward of the laser spot LS1 formed on the mother glass substrate by the laser beam irradiated from the optical holder 33. ), Compressed air, He gas or the like is injected.

In addition, a main cooling nozzle 37 is disposed on the support 31 at intervals of 4 mm or more with respect to the assist cooling nozzle 41. The main cooling nozzle 37 injects a cooling medium such as cooling water, a mixed fluid of water and compressed air, compressed air, and He gas to a rear position of the mother glass substrate cooled by the assist cooling nozzle 41. The cooling temperature of the cooling medium injected from the main cooling nozzle 37 to the mother glass substrate 50 is smaller than the cooling temperature of the cooling medium injected from the assist cooling nozzle 41 to the mother glass substrate 50.

The support wheel 31 is provided with a cutter wheel 35 facing the mother glass substrate 50 placed on the rotary table 26 on the opposite side to the main cooling nozzle 37 with respect to the laser spot LS1 irradiated from the optical holder 33. The cutter wheel 35 is arranged along the major axis direction of the laser spot LS1 irradiated from the optical holder 33, and cuts in the direction along the scribe line to the edge of the mother glass substrate 50 placed on the rotary table 26 (cut line ( cut line).

The positioning of the slide table 12 and the pedestal 19, the rotating mechanism 25, the laser oscillator 34, and the like are controlled by a controller (not shown).

In the case where a blind crack is formed on the surface of the mother glass substrate 50 by such a scribing apparatus, first, information such as the size of the mother glass substrate 50, the position of the scribe line to be input, and the like are input to the controller.

Then, the mother glass substrate 50 is placed on the turntable 26 and fixed by the suction means. In this state, alignment marks formed on the mother glass substrate 50 by the CCD cameras 38 and 39 are captured. The photographed alignment marks are displayed by monitors 28 and 29, and the positional information of the alignment marks on the mother glass substrate 50 is processed by the image processing apparatus.

When the rotary table 26 is positioned relative to the support 31, the rotary table 26 slides along the X direction so that the scribe scheduled line at the edge of the mother glass substrate 50 faces the cutter wheel 35. As shown in FIG. Then, the cutter wheel 35 is lowered to form a cut line (cut line) TR at the edge portion of the scheduled scribe line of the mother glass substrate 50.

Thereafter, the rotary table 26 slides in the X direction along the scribe scheduled line, and a laser beam is oscillated from the laser oscillation device 34, and a cooling medium such as cooling water is injected from the assist cooling nozzle 41, and cooling water and the like from the main cooling nozzle 37. Sprayed with compressed air.

The laser beam LS1 oscillated from the laser oscillation device 34 forms a long elliptical laser spot LS1 along the X-axis direction along the scanning direction of the mother glass substrate 50 on the mother glass substrate 50. At the rear of the laser spot LS1, a cooling medium is ejected along the scribe scheduled line from the assist cooling nozzle 41 to form an assist cooling point ACP. Further, behind the assist cooling point ACP, a cooling medium is injected along the scribe scheduled line SL from the main cooling nozzle 37 to form a main cooling point MCP.

Accordingly, as described above, the assist cooling point ACP is not adopted in the mother glass substrate 50 due to the stress gradient formed by the heating by the laser spot LS1 and the assist cooling point ACP and the cooling by the main cooling point MCP. Compared with the case so far, vertical blind cracks are formed deeper.

When the blind crack is formed on the mother glass substrate 50, the mother glass substrate 50 becomes the force acting on the mother glass substrate is supplied to the next cutting step of the bending moment in the transverse (幅) direction of the blind crack to act. As a result, the mother glass substrate 50 is cut along the blind crack from the cut TR formed in the edge portion thereof.

In the above description of the embodiments, the main cooling point MCP and assist cooling point ACP are formed by directly irradiating the cooling medium on the scribe scheduled line SL from each of the main cooling nozzle 37 and the assist cooling nozzle 41. For example, the main cooling nozzle 37 and the assist cooling nozzle 41 are independently moved in the X direction and the Y direction, and the distance between the laser spot LS1 and the assist cooling point ACP and the assist cooling point ACP and the main cooling point MCP on the scribe scheduled line. It is preferable that it is a structure which allows the space | interval of to be adjusted, or can set the position of the assist cooling point ACP and the main cooling point MCP to the position which shifted on the scribe plan line.

In addition, in the embodiment of the present invention, as one example of the brittle material substrate has been described by using the mother glass substrate of the liquid crystal display panel, the present invention is bonded glass substrate (glass接合基板), single-plate glass (單板glass), a semiconductor wafer ( The present invention can also be applied to scribe processing such as a thin wafer and ceramics.

In the above description, the case where the thermal energy intensity of the outer circumferential edge portion of the laser spot LS1 formed on the mother glass substrate 50 is larger than the thermal energy intensity of the center portion has been described, but the thermal energy distribution of the laser spot LS1 may be a Gaussian distribution. .

(Example)                 

Next, the Example which forms a blind crack in a glass substrate on various conditions using this scribe apparatus is demonstrated.

Example 1

A laser beam oscillated from the laser oscillator 34 was set to 200 W to irradiate a soda glass substrate having a thickness of 3.0 mm to form a blind crack. The laser spot LS1 formed on the glass substrate has, for example, an elliptical shape having a long axis of 40 mm and a short axis of 1.5 mm, and the main cooling point MCP formed of a refrigerant injected from the main cooling nozzle 37. The assist cooling point ACP, which is formed 85 mm from the center of the laser spot LS1 and is formed by the refrigerant injected from the assist cooling nozzle 41, is formed at a position of 10 mm from the main cooling point MCP to the laser spot LS1, respectively.

For the main cooling nozzle 37, the inner diameter of the tip of the nozzle is 0.6 mm, and for the assist cooling nozzle 41, the inner diameter of the tip of the nozzle is 0.8 mm.

From the main cooling nozzle 37, a mixed fluid of water and compressed air is injected from the height of 5 mm against the surface of the glass substrate at a pressure of 0.5 MPa (flow rate: 10 L / min). In addition, the assist cooling nozzle 41 is configured to blow compressed air at a height of 0.2 MPa (flow rate: 14 L / min) from the height of 1 mm to the surface of the glass substrate. In addition, the moving speed of the glass substrate, by 180mm / s change to 10mm / s by stepwise from 100mm / s to form a blind crack in the glass substrate was measured, the depth δ. The results are shown in the graph of FIG. For comparison, the depth δ of the blind crack when the assist cooling point ACP was not formed by the assist cooling nozzle 41 was written in the graph of FIG. 3.

In this case, by forming the assist cooling point ACP by the assist cooling nozzle 41, the depth of the blind crack δ is about 10% deeper than when the assist cooling point ACP is not formed.

Example 2

A 1.1 mm thick soda glass substrate is used to inject a mixture of water and compressed air from the main cooling nozzle 37 at a pressure of 0.5 MPa (flow rate: 10 L / min) and to provide compressed air from the assist cooling nozzle 41. The injection was made at a pressure of 0.2 MPa (flow rate: 14 L / min), and the assist cooling nozzles 41 were disposed at intervals of 7 mm with respect to the main cooling nozzles 37. And the movement speed of the glass substrate to thereby 400mm / s change to 20mm / s by stepwise from 100mm / s to form a blind crack in the glass substrate was measured, the depth δ. The results are shown in the graph of FIG. For comparison, the depth δ of the blind crack when the assist cooling point ACP is not formed by the assist cooling nozzle 41 is shown in the graph of FIG. 4.

Incidentally, the other conditions were the same as those in the first embodiment.

Also in this case, by forming the assist cooling point ACP by the assist cooling nozzle 41, the depth of the blind crack δ is about 10% deeper than when the assist cooling point ACP is not formed.

Example 3

The position of the assist cooling point ACP by the assist cooling nozzle 41 is changed from 0 mm to 15 mm with respect to the main cooling point MCP by the main cooling nozzle 37, and the pressure when the cooling medium is ejected by the assist cooling nozzle 41 is 0.1 MPa. The depth δ was measured by forming a blind crack under the same conditions as in Example 1 except that the flow rate was changed to 7 L / min, 0.2 MPa (14 L / min) and 0.3 MPa (21 L / min). The results are shown in the graph of FIG.

In this case, by forming the assist cooling point ACP on the glass substrate so that the distance between the assist cooling nozzle 41 and the main cooling nozzle 37 is about 10 mm, the depth of the blind crack as compared with the case where the assist cooling point ACP is not formed. Became about 10% deeper.

Example 4

The pressure at which the position of the assist cooling point ACP by the assist cooling nozzle 41 is changed from 5 mm to 9 mm at a distance from the main cooling point MCP by the main cooling nozzle 37, and the cooling medium is ejected by the assist cooling nozzle 41. Was changed to 0.1 MPa (7 L / min), 0.2 MPa (14 L / min) and 0.3 MPa (21 L / min), except that blind cracks were formed under the same conditions as in Example 2, and the depth δ was measured. The results are shown in the graph of FIG.                 

In this case also, the assist cooling point ACP is formed on the glass substrate so that the distance between the assist cooling nozzle 41 and the main cooling nozzle 37 is about 7 mm, and thus the depth of the blind crack as compared with the case where the assist cooling point ACP is not formed. Became about 10% deeper.

7 is a schematic plan view showing another embodiment of the present invention. By the laser beam oscillated from the laser oscillation unit 34 along the scanning direction of the mother glass substrate 50 formed on the mother glass substrate 50, the laser spot LS1 on a long oval shape is formed along the X-axis direction. In the rear of the laser spot LS1, a cooling medium is injected along the scribe scheduled line from the plurality of assist cooling nozzles 41 to form a plurality of assist cooling points ACP. Further, behind the plurality of assist cooling point ACPs, a cooling medium is injected from the main cooling nozzle 37 along the scribe scheduled line SL to form the main cooling point MCP.

After the surface of the mother glass substrate 50 is sequentially heated by the laser spot LS1 along the scribe scheduled line SL, the surface of the mother glass substrate 50 is sequentially controlled by a plurality of assist cooling point ACP immediately before the heating portion is cooled by the main cooling point MCP. The cooling is performed at a temperature higher than the temperature of the refrigerant forming the cooling point MCP, and then cooled by a temperature lower than the temperature of the refrigerant forming the assist cooling point ACP by 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 after that, the mother glass substrate 50 is once cooled by the plurality of assist cooling point ACPs, and then further cooled by the main cooling point MCP. As a result, a line of blind cracks deepened in the vertical direction along the scribe line is formed.

In addition, in the scribing method using the laser of the prior art shown in Fig. 8, after cooling the surface of the mother glass substrate 50 by laser spot LS, the cooling medium is sprayed to cool the surface of the mother glass substrate 50, so that the blind crack is removed. After formation it is believed that unwanted thermal shock occurs.

By providing a plurality of assist cooling point ACPs on the laser spot LS1 side from the main cooling point MCP, the above unnecessary thermal shocks are alleviated, and it is considered that energy lost by the thermal shocks is consumed by the force for extending the blind crack. By plural cooling points, the mother glass substrate can be sequentially cooled to eliminate the occurrence of unnecessary thermal shock, thereby forming a blind crack (vertical crack) deeper than when there is only one assist cooling point.

The cooling medium for forming the main cooling point and the assist cooling point on the glass substrate is the same as the case where the above one assist cooling point is formed on the mother glass substrate, and thus, the detailed description will not be given herein.

In addition, the scribing apparatus includes, for example, a mechanism in which the main cooling nozzle 37 and the plurality of assist cooling nozzles 41 are independently moved in the X direction and the Y direction, so that the laser spot LS1 and the laser spot are most on the scribe schedule line. The distance between the assist cooling point ACP located on the side, the assist cooling point ACP and the main cooling point MCP located on the most main cooling point MCP side, and the mutual distance between the plurality of assist cooling points can be adjusted, and the plurality of assist cooling points are also adjusted. It is preferable that the position of the point ACP and the main cooling point MCP be set to the position which shifted on the scribe plan line.

Thus, the present invention is achieved by providing at least one assist cooling point between the laser spot on the mother glass substrate and the main cooling point.

The scribing method and apparatus for brittle material substrates in the present invention are assisted cooling spots at positions close to the main cooling spots between the laser spots formed on the surface of the brittle material substrates such as mother glass substrates and the main cooling spots. Since it is possible to form blind cracks deeply, blind cracks can be efficiently formed.

Claims (3)

A laser beam is formed along the scribe setting line on the surface of the brittle material substrate to form a laser spot at a temperature lower than the softening point of the brittle material substrate. While continuously irradiating and moving a laser beam, a cooling spot is formed by cooling a vicinity of an area along the scribe scheduled line behind the laser spot with a cooling medium to form a cooling spot. In the scribing method of a brittle material substrate to continuously form a blind crack along the The scribing of the brittle material substrate, characterized in that the laser spot is formed on the side of the laser spot rather than the cooling spot while forming at least one assist cooling spot for cooling the area along the scribe line in advance by the refrigerant. Scribe method. The method of claim 1, And the assist cooling spot is formed by a refrigerant having a cooling temperature higher than that of the refrigerant forming the cooling spot. Laser beam irradiation means for moving while continuously irradiating a laser beam such that a laser spot having a temperature lower than the softening point of the brittle material substrate is formed on the surface of the brittle material substrate; Blind cracks along the scribe line on the surface of the brittle material substrate, with cooling means for continuously cooling the area near the region along the scribe line on the rear of the region heated by the laser spot with a coolant. In the scribing apparatus of a brittle material substrate to form a, At least one assist cooling means for cooling the area on the laser spot side formed by the laser beam irradiation means rather than the area cooled by the cooling means by a refrigerant having a temperature higher than the temperature of the refrigerant of the cooling means. ) A scribing apparatus for a brittle material substrate, characterized in that it comprises a.

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