TWI462792B - Lightning scribing method and mine scribing device for brittle material substrate - Google Patents

Description

Laser scribing method for brittle material substrate and laser scribing device

The present invention relates to a laser scribing method and a laser scribing device for forming a scribe line by irradiating a laser beam onto a brittle material substrate to cause a vertical crack to occur on the substrate, in particular, coating a transparent conductive film or the like. A scribing method and a scribing device for irradiating laser light to form a slab brittle material substrate in the vicinity of a coating film of a brittle material substrate of a film or an edge of a brittle material substrate.

Here, the brittle material substrate means a glass substrate, a ceramic of a sintered material, a single crystal germanium, a semiconductor wafer, a ceramic substrate, a sapphire substrate, or the like. Further, the brittle material substrate includes a bonding substrate on which the substrate is bonded, in addition to a single board composed of one substrate.

It is known that a brittle substrate such as a glass substrate or a sapphire substrate is used, and a heating point (also referred to as a beam spot) formed on a substrate by irradiation of a laser beam is relatively moved along a predetermined line of a predetermined line on the substrate to heat the substrate. Further, a cooling point formed by the ejection of the refrigerant is moved as follows following the trajectory of the heating point to cool the substrate, thereby forming a laser scribing method for scribing on a predetermined line of the scribe line (see, for example, Patent Document 1).

Such laser scribing is based on the formation of a vertical crack based on the compressive stress generated around the heating point and the tensile stress generated around the cooling point. At this time, a scoring (initial crack) is formed on the end surface of the substrate by using a tool such as a scribing wheel before the vertical crack is formed, and then the heating point generated by scanning the laser beam and the cooling point generated by the refrigerant are started by using the scoring as a starting point. Thereby, the vertical cracks which are impregnated in the thickness direction of the substrate progress in the direction of the surface of the substrate.

Generally, in the laser scribing process, the beam spot of the laser beam is shaped into a bilaterally symmetrical shape (circle, ellipse, oblong, etc.), and the illumination position is positioned such that the center of the beam spot is routed through the line of the scribe line before scanning the laser. beam. Specifically, the circular beam point is the center of the circle, and the elliptical or oblong beam point is the center of the beam point in the left-right direction, the center line of the front-rear direction, that is, the intersection of the major axis and the minor axis, so that It scans in a manner that moves on a predetermined line of the line.

Further, a brittle material substrate such as a glass substrate subjected to laser scribing is used to prevent obstacles in the vicinity of a predetermined line of the line to be scanned.

Under such conditions, the laser scribing process is performed such that the thermal stresses occurring in the regions on the left and right sides of the traveling line (i.e., the predetermined line of the scribe line) moving at the center of the clip beam point are equal and move at the center of the beam spot. The thermal stress near the lower line of the traveling line is the largest, and as a result, the crack due to the thermal stress is formed near the lower side of the traveling line (near the line below the predetermined line).

Patent Document 1 Japanese Patent No. 3027768

Conventional laser scribing methods are premised on the existence of a factor that includes a predetermined line of scribe lines that does not interfere with the illumination of the irradiated laser in the vicinity of the line. It is considered to be a substance that hinders the cause, such as that which is present on the substrate and which is different from the case of only the substrate, and which is abnormally absorbed or reflected by the irradiated laser beam. If such a substance exists in the vicinity of a predetermined line on the substrate, the light energy absorbed in the substrate on the left and right sides of the line when the center of the laser beam moves on the line is different, and the magnitude of the thermal stress generated is also different. As a result, the change in thermal stress that occurs when the vicinity of the predetermined line is cooled is also different on the line. At this point, the resulting crack will not coincide with the position of the predetermined line. Specifically, in the case of the following, the crack and the line to be scribed may not coincide.

(the first situation)

A substance that hinders the heating caused by the irradiation of the laser light is present as a foreign matter on the substrate. In a specific example, a substrate for a flat panel display (FPD), which is a flat display, is used. In the film formation process in which a TFT element or the like is formed, a film component which is not formed in the vicinity of a predetermined line of scribe lines is erroneously attached or should be The film component that has been removed by the previous treatment remains in the vicinity of the predetermined line of the scribe line. In each case, when the film component has an optical characteristic that is greatly affected by the laser beam irradiated onto the substrate, the film component exists in the vicinity of the predetermined line of the scribe line and is irradiated onto the substrate by the laser beam to the substrate. When the influence of heat is greatly different on the left and right sides of the line, the position of the crack formed by the laser heating and cooling is deviated from the position of the predetermined line of the scribe line.

(the second situation)

A transparent conductive film formed as a functional member is provided on the substrate, and it is necessary to draw a line as close as possible to the vicinity of the conductive film to form a crack. For example, it is conceivable to take into consideration the size of the substrate and the size of the resulting display screen to produce the above-mentioned demand. In such a transparent conductive film, the laser beam irradiated to the substrate is reflected, and the film component exists in the vicinity of the predetermined line of the scribe line and the influence of the laser beam irradiated onto the substrate on the heat of the substrate greatly differs between the lines on the line The position of the crack formed by the laser heating and cooling also deviates from the position of the predetermined line of the scribe line.

(the third situation)

It is necessary to scribe the vicinity of the substrate end as close as possible to the substrate end to make the crack form. For example, it is conceivable to take into consideration the size of the substrate and the size of the resulting display screen to produce the above-mentioned demand. At this time, there is a substrate end near the predetermined line of the scribe line, and one of the laser beams is not irradiated onto the substrate, and the influence of the heat on the substrate is greatly different when the left and right sides of the line are substantially different, and the crack formed by the laser heating and cooling is formed. The position also deviates from the position of the line to be scribed.

That is, if foreign matter is asymmetrically present in the vicinity of the line to be scribed, the laser light is irradiated to the foreign matter portion, and one portion of the laser light is reflected and absorbed by the foreign matter. As a result, the irradiation area of the substrate differs around the predetermined line of the scribe line, and an error occurs in the energy absorbed by the substrate.

Further, an ITO film may be applied as a transparent conductive film on a glass substrate or the like. The ITO film has a characteristic of reflecting light of a wavelength of a CO ₂ laser. Thus, when the glass substrate and irradiated with a CO ₂ laser is reflected at the surface of the ITO film, a glass substrate under the ITO film side of the area and substantially reduces the energy absorbed by the substrate, the temperature rise is suppressed not illuminated.

On the other hand, when the coating film has the property of absorbing the wavelength light of the laser beam, the glass substrate region on the lower side of the coating film substantially increases the absorption energy, and the temperature rise is accelerated.

Further, the thickness of the coating film formed in the vicinity of the predetermined line of the scribe line may also change the energy absorbed.

Further, when the film thickness of the coating film is close to the wavelength of the laser light, multiple reflection occurs, and when the relationship between the wavelength of the laser light and the film thickness of the coating film satisfies a specific condition, even if it is a coating film having absorption characteristics, absorption is also performed. It may become extremely small and absorb energy changes. On the other hand, even in the case of a coating film having a reflection property, when the relationship between the wavelength of the laser light and the film thickness of the coating film satisfies a specific condition, the absorption may become extremely large and the absorption energy changes.

If the asymmetric arrangement of the foreign matter such as the coating film in the vicinity of the predetermined line is caused to affect the energy absorbed by the substrate, the heat distribution generated on the substrate is also on the predetermined line. The left and right sides become asymmetrical, and the heat distribution occurring inside the substrate is also asymmetric around the predetermined line of the scribe line. If the heat distribution is asymmetrical, the thermal stress change caused by the refrigerant injection after the laser irradiation is also asymmetric around the predetermined line of the scribe line, and as a result, the position where the scribe line (crack) is actually formed is predetermined from the scribe line. Line deviation.

Further, when a scribe line is formed in the vicinity of the end portion of the substrate, if the laser beam is moved along the predetermined line of the scribe line near the end portion and irradiated, the beam spot on the end side of the substrate is irradiated only to the substrate. One end is exposed from the substrate end. As a result, the predetermined line of the underlined line has different irradiation areas on the left and right sides, and the absorbed energy is also different, and the distribution of the thermal stress is still asymmetrical around the predetermined line of the scribe line. As a result, the position at which the scribe line (crack) is actually formed is deviated from the predetermined line of the scribe line.

A specific example in which a scribe line formed in the vicinity of a predetermined line of scribe line or a scribe line formed on the end of the substrate is formed will be described with reference to the drawing.

Fig. 14 is a view showing an example in which a unit display substrate U is cut out from one glass mother substrate A by a laser scribing method.

The center of the beam point P of the oblong shape (the center line of the left-right direction, that is, the intersection of the long axis and the center line of the front-rear direction, that is, the short axis) is set on the mother substrate A set to the laser scribing apparatus to be on the predetermined line S The upper moving mode is scanned for local heating, and the refrigerant (not shown) is blown by following the trajectory of the beam spot P to cool.

When there is a coating film region C (foreign matter) such as a transparent conductive film in the region where the unit display substrate U is present, if the vicinity of the edge C1 of the coating film region C is scanned along the predetermined line S of the laser beam, the beam spot of the laser beam is scanned. P, one portion of the beam spot P is also irradiated to the cladding film region C near the predetermined line S.

At this time, the portion where the coating film region C exists and the portion of the beam spot P which is not present in the coating film region C are different in the degree of absorption of heat (that is, the degree of heat reflection is different), so The heat distribution of the surface of the substrate when the left and right beam spots P of the predetermined line S is passed becomes asymmetrical.

At this time, the scribe line T1 at the position where the beam spot P and the coating film region C do not intersect with each other coincides with the scribe line S, and the scribe line T2 at the region where the beam spot P and the coating film region C intersect each other The coating film region C is away from the scribe line S.

Therefore, a positional shift occurs between the formed scribe line T1 and the scribe line T2.

Moreover, FIG. 15 is a view showing an example in which the unit display substrate U is cut out in the vicinity of the substrate end of one glass mother substrate A. The center of the circular beam point P (the beam shape is an ellipse or an ellipse as shown in FIG. 14) is scanned with respect to the mother substrate A set to the laser scribing device to move on the predetermined line S of the scribe line. Local heating is performed, and a refrigerant (not shown) is blown to follow the trajectory of the beam spot P to cool.

When the scribe line S is set at a position where the distance d2 from the edge M1 of the substrate to the predetermined line S is smaller than the distance d1 from the edge C1 of the coating film region C to the predetermined line S of the scribe line, the substrate is The oblique line portion in the map of the irradiated beam point P is not irradiated to the substrate A and is deviated outside the substrate. Therefore, the irradiation area on the left and right sides of the scribe line S is different, and the heat distribution generated by the laser irradiation on the surface of the substrate A becomes asymmetric about the line S of the scribe line, and is the same as the position where the foreign matter is asymmetric. The problem of shifting occurs.

Further, the line S of the scribe line is non-parallel to the edge M1 of the substrate A, and the distance from the predetermined line S to the edge M1 is varied, and the heat distribution by the laser irradiation is still on the scribe line S. The left and right become asymmetrical, and the same problem arises.

Further, the above problem is also likely to occur in a substrate composed of a material other than glass.

In view of the above problems, in the first aspect of the present invention, it is possible to perform laser scribing processing by avoiding the influence of the presence of foreign matter such as a coating film which is obstructed by irradiation in the vicinity of a predetermined line.

Secondly, even if a transparent conductive film (such as an ITO film) is formed on a substrate such as a glass substrate for a flat panel display, it can be regarded as a foreign matter, and a predetermined line is set in the vicinity thereof, and a line is drawn along the line. The scribing method of processing is for the purpose.

Thirdly, it is intended to provide a scribing method in which scribing is performed along a predetermined line of scribing even if it is a predetermined line for scribing near the end of the substrate.

In order to solve the above problems, the present invention heats the substrate by moving the laser beam irradiation mechanism relative to the brittle material substrate and irradiating the laser beam to scan the beam spot of the laser beam along a predetermined line of the scribe line, thereby heating the substrate. The laser scribing method for cooling the substrate to form a slab brittle material substrate along a predetermined line of scribe line, and arranging the laser light to a surface of the substrate irradiated with the laser light to a predetermined line of the scribe line The range of the surface of the substrate on which the laser light is irradiated in a state where the symmetrical irradiation area adjusting means is mounted on one of the surfaces of the laser beam irradiation means or the substrate irradiates the laser beam to the area where the predetermined line of the scribe line is asymmetric .

Here, the laser beam can be used for a laser that is generally used for a material corresponding to a substrate of a brittle material, and can be applied to a laser such as an excimer laser, a YAG laser, a CO ₂ laser, or a CO laser. In the practice of the invention.

Further, "the range of the surface of the substrate on which the laser light is irradiated is an asymmetrical region to the predetermined line of the scribe line". Specifically, the state of the surface of the substrate including the vicinity of the predetermined line is a difference between the left and right, and a predetermined line for the scribe line. On the surface of the substrate nearby, foreign matter such as a coating film is asymmetrically formed, and the shape of the substrate in the vicinity of the left and right sides of the predetermined line is different.

According to the present invention, an irradiation area adjusting means is attached to one of the surfaces of the laser beam irradiation means or the substrate. When scanning the beam spot of the laser beam along a predetermined line of the scribe line, the range of the surface of the substrate on which the laser light is irradiated is asymmetric with respect to the predetermined line of the scribe line, and the laser light is shielded into the laser light by the irradiation area adjusting means. The range of the surface of the substrate to be illuminated is symmetrical with respect to the predetermined line of the scribe line. Thereby, the heat distribution on the left and right sides is adjusted to be symmetrical with respect to the entire line of the scribe line. As a result, a line with good straightness can be formed.

(means and effects to solve other problems)

In the above invention, the brittle material substrate can form a coating film region on one surface of the substrate, and the coating film region is provided at a position where one of the scanned beam spots passes through the coating film region.

Here, the "coating film" forming the coating film region is not particularly limited as long as it has a reflection property or an absorption property to the laser beam. For example, a transparent conductive film (for example, an ITO film) used for electrode or non-reflective coating, a metal film (for example, aluminum, silver, gold) used as an electrode or a light reflecting surface is exemplified. As another example, it may be a photoresist film, various protective films, or various functional films.

According to the present invention, even if a coating film is formed in the vicinity of a predetermined line of scribe line, the scribe line can be formed without being affected by the coating film, and as a result, a scribe line having good straightness can be formed.

Further, in the above invention, the beam spot may be scanned by one of the scanned beam spots to pass through the outside of the substrate.

According to the present invention, even in a case where, for example, a predetermined line of the scribe line is set at a position close to the edge of the substrate, a predetermined line of the scribe line cannot be set to a position parallel to the edge of the substrate, or a substrate end near the predetermined line of the scribe line The beam spot from the laser beam irradiation mechanism is irradiated to the edge of the predetermined line in the width direction, and the line is not affected by the distance from the predetermined line to the edge of the substrate, thereby forming a straight line with good straightness. line.

Further, in the above invention, the irradiation area adjusting means attached to the laser beam irradiation means may be constituted by a shutter member that is shielded from light in a manner that reduces the expansion of the beam spot in the width direction of the predetermined line of the scribe line, and restricts the door member. The opening is such that the heat distribution generated by the surface of the substrate by the beam spot irradiated to the substrate through the shutter member is bilaterally symmetrical with respect to a predetermined line of the scribe line.

According to the present invention, by reducing the opening of the shutter member, the expansion of the beam spot in the width direction of the predetermined line of the scribe line (that is, the width of the beam spot, hereinafter referred to as the beam spot width) is reduced, and the beam spot is made on the entire line of the scribe line. The generated heat distribution is to illuminate the substrate symmetrically with respect to a predetermined line of the scribe line. Thereby, a straight line with good straightness can be formed.

Further, the shape of the beam spot of the laser beam is preferably a shape in which the heat distribution is symmetrical with respect to a predetermined line of the scribe line. For example, it is generally circular, elliptical or oblong, but the shape is substantially not limited as long as it is substantially bilaterally symmetrical.

For example, a pair of beam spots may be formed to be separated from a position symmetrical with respect to a predetermined line of the scribe line and formed in a bilaterally symmetrical shape. Forming a pair of beam spots as described above can improve the stress distribution in the vicinity of the predetermined line of the scribe line, so that the vertical crack progresses in the thickness direction of the substrate (refer to WO2006/038365).

Moreover, in the above invention, the irradiation area adjusting means attached to the brittle material substrate may be constituted by a temporary coating film formed on the opposite side of the coating film region in the vicinity of the predetermined line of the scribe line along the predetermined line of the scribe line.

According to the present invention, when the coating film region is formed on either side of the predetermined line of the scribe line, the predetermined line of the scribe line is formed on the other side to form the temporary coating film, so that the reflection and absorption of the laser beam can cause heat. The influence is balanced to the left and right of the planned line of the scribe line so that the heat distribution is symmetrical about the left and right lines of the scribe line.

Here, the material of the temporary coating film is not particularly limited, and may be the same as the material for forming the coating film region, and may have different optical properties such as reflection and absorption. For example, when a transparent conductive film (for example, an ITO film or the like) used as an electrode or a non-reflective coating is formed on one side of a predetermined line of a scribe line as a coating film region, a temporary transparent conductive film may be formed on the other side. Cover film. The mother substrate for a liquid crystal display panel has a pattern in which a transparent conductive film is formed as a coating film region. However, when the transparent conductive film pattern is formed, a predetermined line in which a transparent conductive film is not originally formed is formed. The temporary coating film can be efficiently formed by simultaneously forming a temporary coating film in a region on the opposite side of the coating film region.

According to another aspect of the present invention, a laser scribing apparatus is provided with a laser beam irradiation mechanism, a cooling mechanism, and the laser beam irradiation mechanism and the cooling mechanism are moved relative to the substrate. The scanning mechanism moves the laser beam irradiation mechanism relative to the substrate such that the beam spot of the laser beam is scanned along a predetermined line of the substrate and is scanned on the predetermined line of the scribe line to heat the substrate at a temperature below the softening point. a laser scribe line device for a brittle material substrate which is formed by moving a light guide along a trajectory of a beam spot to cool the substrate to form a scribe line along a predetermined line of scribe lines, and has an expansion of a beam spot in a width direction of a predetermined line of the scribe line The heat distribution on the surface caused by the beam spot being irradiated onto the substrate is a gate that is symmetrical about the entire length of the predetermined line.

According to the present invention, the beam width of the beam spot is reduced by the shutter, and the heat generated by the beam spot is distributed to the entire line of the scribe line to be bilaterally symmetrical with respect to the predetermined line of the scribe line. Thereby, a straight line with good straightness can be formed.

In the scribing device, the shutter has a door width adjusting mechanism for adjusting an expansion of a beam spot in a width direction of a predetermined line of a scribe line, and an expansion of a beam spot in a width direction of a predetermined line of the scribe line is set to a predetermined line from a scribe line. Up to 2 times or less the shortest distance between the coating film region and the substrate edge existing in the vicinity of the predetermined line of the scribe line.

According to the present invention, since the beam spot does not touch the cover film region and the substrate edge when the beam spot is scanned, the heat distribution can be made symmetric by illuminating the beam spot symmetrically along the predetermined line of the scribe line.

In the above-described scribing device, the shutter has a door width adjusting mechanism that adjusts the expansion of the beam spot in the width direction of the predetermined line of the scribe line, and further includes a scanning mechanism that relatively moves along the entire line of the predetermined line and captures the image. a camera portion of the image of the coating film and the image of the edge of the substrate near the predetermined line of the line, based on the image information captured by the camera unit, extracting the shortest distance from the predetermined line of the scribe line to the edge of the film or the edge of the substrate and based on the extraction The shortest distance determines the beam spot width in the width direction of the predetermined line to control the door width control portion of the door width adjusting mechanism.

According to the present invention, the camera unit is relatively moved along the entire length of the predetermined line by the scanning mechanism, and the coating film region and the substrate end edge existing in the vicinity of the predetermined line are drawn. The door width control unit extracts the shortest distance from the predetermined line of the scribe line to the cover film area or the edge of the substrate from the captured image information. Then, based on the shortest distance extracted, the beam spot width in the width direction of the predetermined line is determined to control the gate width adjusting mechanism to control the beam width.

Thereby, the shortest distance to the coating film region existing near the predetermined line of the scribe line and the edge of the substrate can be automatically detected, and the width of the spot to be irradiated can be automatically adjusted.

In the scribing device, the shutter has a door width adjusting mechanism for adjusting an expansion of a beam spot in a width direction of a predetermined line of scribe lines, and further includes a predetermined line from a scribe line to a coating film region or a substrate edge The shortest distance is the distance from the data input data input unit, the distance data input from the data input unit is recorded, the distance data recorded in the distance from the data recording unit is read, and the line is determined based on the read distance data. The beam spot width in the width direction of the predetermined line is controlled to control the door width control portion of the door width adjusting mechanism.

According to the present invention, the shortest distance from the predetermined line of the scribe line to the edge of the coating film or the edge of the substrate is input in advance by distance data, so that the distance data input is recorded. The door width control unit reads the recorded distance data and determines the beam spot width in the width direction of the predetermined line based on the read distance data to control the door width adjusting mechanism.

Thereby, the width of the spot to be irradiated can be automatically adjusted as long as the shortest distance between the coating film region existing near the predetermined line of the scribe line and the edge of the substrate is recorded.

(Embodiment 1)

Hereinafter, embodiments of the present invention will be described based on the drawings. Fig. 1 is a schematic configuration diagram of a laser scribing device LS1 according to an embodiment of the present invention. Fig. 2 is a view showing the configuration of a control system of the laser scribing device LS1 of Fig. 1. Fig. 3 is a view for explaining the configuration of an optical holder in which an optical system for adjusting a beam spot is incorporated.

First, the overall configuration of the laser scribing device LS1 will be described based on Fig. 1 .

The pair of guide rails 3, 4, which are arranged in parallel on the horizontal stage 1, are provided with a sliding platform 2 which reciprocates in the rear direction (hereinafter referred to as the Y direction) of the paper of Fig. 1. A lead screw 5 is disposed between the two guide rails 3 and 4 in the Y direction, and the lead screw 5 is screwed to the support post 6 fixed to the sliding platform 2 by a motor (illustrated The forward/reverse lead screw 5 reciprocates the slide platform 2 along the guide rails 3, 4 in the Y direction.

A water platform seat 7 that reciprocates in the left-right direction (hereinafter referred to as the X direction) of FIG. 1 is disposed on the slide platform 2 along the guide rail 8. The lead screw 10 fixed to the pedestal 7 is screwed with a lead screw 10a that is rotated by the motor 9, and the lead screw 10a is reversible so that the pedestal 7 reciprocates along the guide rail 8 in the X direction.

The pedestal 7 is provided with a rotating platform 12 that is rotated by a rotating mechanism 11, and the rotating platform 12 is mounted with a brittle material substrate such as a glass substrate, which is an object to be cut, in a horizontal state (hereinafter, simply referred to as a mother substrate A). The rotating mechanism 11 rotates the rotating platform 12 about a vertical axis and is rotatable to an arbitrary rotation angle with respect to the reference position. Further, the mother substrate A, which is the object to be separated, is fixed to the rotary table 12 by, for example, a suction chuck.

Above the rotating platform 12, an optical holder 14 connected to the laser oscillator 13 is held by the mounting frame 15. The laser beam emitted by the laser oscillator is a beam point of a predetermined shape (here, a beam point of a substantially oblong shape extending in a predetermined line direction along the scribe line) by an optical system inside the optical holder 14. Irradiation onto the mother substrate A. In addition, the optical system inside the optical holder 14 will be described later.

A pair of CCD cameras 20 (21) that are freely positionally adjustable are disposed above the rotating platform 12. The mother substrate A, which is the object to be cut, is provided with one of the processing reference marks which are normally set on the rotating table 12 at both ends of the substrate, and the pair of CCD cameras 20 (21) are respectively arranged to be separately separable. Take these alignment marks. Further, in Fig. 1, only the CCD camera 20 on the near side of the paper surface is displayed, and the CCD camera 21 on the far side of the paper surface is not displayed.

The optical holder 14 is controlled to move over the rotating platform 12 by the control unit 56 of FIG. In general, in the basic machine configuration using a laser scribing device, the center position of the beam spot formed on the mother substrate A due to the emission of the laser beam is generally inconsistent with the center position of the optical holder 14, but will lie in The coordinate of the center position of the optical holder 14 that moves away from the surface at a predetermined distance from the surface of the object to be processed is regarded as coordinate data processing, whereby the control device side can measure the center position of the beam spot irradiation as position data. If the position of the other device portion is used as the coordinate data, the offset amount is recorded in the control unit of the mobile data of the management device, and the movement of the optical holder 14 can be controlled in accordance with the need to increase or decrease the amount of the offset.

Further, when the shape of the light beam emitted from the optical holder 14 is substantially circular, and the center coordinate (Rx, Ry) is the central coordinate data of the light beam, if the beam shape is a shape extending in the traveling direction and is in the traveling direction Symmetrical ellipse, with the position where the long axis and the short axis intersect (Ex, Ey) is the central coordinate data of the beam.

When the center position of the beam does not coincide with the center position of the optical holder 14, the value of the difference between the two positions is regarded as the amount of deviation. As long as the position of one of the positions is grasped, the position of the other can be quickly added by the amount of offset. Seek.

For example, the offset of the center position coordinate of the optical holder 14 and the center coordinate (Rx, Ry) of the light beam is used as the offset amount, and the position data of the optical holder 14 is input into the program in advance by the control data of the device. The actual coordinate position of the light beam on the substrate can be determined by the calculation of the amount of deviation when necessary.

In addition, grasp the coordinates of the beam and the seat of the optical holder 14 described above. The data can be confirmed by screening the current position of the optical holder 14 in the scribing action and the current position of the center of the beam on the display connected to the control unit.

In the following description, for simplification, it is assumed that the center position of the beam coincides with the center position of the optical holder 14.

Further, a cooling nozzle 16 is provided in the mounting frame 15 near the optical holder 14. Thereby, the cooling nozzle 16 sprays a cooling medium such as cooling water, helium gas or carbon dioxide gas to the glass substrate. This cooling medium is blown to a position close to the end in the longitudinal direction of the beam spot irradiated from the optical holder 14 to the mother substrate A, and a cooling point is formed on the surface of the mother substrate A.

Further, the scribing wheel 18 is attached through the vertical movement adjustment mechanism 17. The scribing wheel 18 is made of sintered diamond or superhard alloy, and has a V-shaped ridge line portion whose apex is the leading edge of the blade on the outer peripheral surface, and the crimping force to the mother substrate A can be finely adjusted by the up-and-down movement adjusting mechanism 17 . The scribing wheel 18 is used to move the pedestal 7 from the standby position to the X direction when the initial crack is formed at the edge of the mother substrate A, and the scribing wheel 18 is temporarily lowered to return to the standby position.

Next, the control system will be described based on Fig. 2 . The laser scribing device LS1 drives a platform driving portion 51 of a motor (motor 9 or the like) that performs positioning of the sliding platform 2 and the pedestal 7, and a laser driving portion 52 that drives the laser oscillator 13 for irradiation of a laser beam. The nozzle drive unit 53 that drives the on-off valve (not shown) that is connected to the cooling nozzle 16 and controls the injection of the refrigerant, the wheel drive unit 54 that performs the positioning of the scribing wheel 18 and the adjustment of the pressure contact force to the mother substrate A, and blocks Each of the drive systems of the door drive unit 55 that adjusts the opening width Wo of the door 44 is controlled by a control unit 56 composed of a computer (CPU). An input unit (not shown) including an input device such as a keyboard or a mouse is connected to the control unit 56, and various displays are performed. The display unit 58 that displays the screen configuration can display the necessary information on the display screen and can input the necessary instructions or settings.

Further, the control unit 56 further includes a distance data input unit 57 that inputs the coordinate data corresponding to the shortest distance from the planned line S to the coating film area C or the substrate edge M1, and the distance is entered. The distance data recording unit 59 that inputs the distance data from the data input unit 57 reads the distance data recorded in the distance from the data recording unit 59 and determines the expansion of the beam spot in the width direction of the predetermined line of the scribe line, that is, the limit beam spot width W. The door width control unit 44 that adjusts the opening width Wo of the shutter 44b based on the read distance data. Thereby, the opening width Wo of the shutter panel 44b can be automatically determined and then scribed.

The internal configuration of the optical holder 14 will be described below based on FIG. As shown in FIG. 3, the optical holder 14 is provided with collecting lenses 42 and 43 for deforming the laser beam LB from the laser oscillator 13 into a laser beam LC having a long-circular beam spot, and shielding the laser beam LC. The outer portion is such that it is a shutter 44 that limits the beam spot LD of the beam width. In addition, the limit point width of the restriction beam spot LD is represented by W.

Further, as shown in FIG. 4, a light-shielding portion may be provided along a center line of the long-axis direction of the beam spot LD, and a pair of restricted beam spots LD2 having a width of the restriction point of W may be formed. At this time, an optical dividing element 41 (for example, a slit plate that shields the center line) that shields the central portion of the beam spot is mounted on the optical path. Thereby, a scribe line which progresses vertically to a deeper position can be formed in the thickness direction of the substrate.

Further, as shown in FIG. 4, a light beam point in which a non-irradiated portion which is not irradiated with a laser beam is formed on a scribe line is described in Patent Document 3 below. Such The beam point is irradiated by the laser beam and the refrigerant jet prevents the internal compressive force field from being formed near the bottom of the scribe line in the thickness direction of the brittle material substrate when the vertical crack progresses, so that the thickness direction of the brittle material substrate can be A completely vertical crack is formed (refer to WO2006/038365).

FIG. 5 is a schematic configuration view showing the configuration of the shutter 44. The shutter 44 is provided with a shutter 44b formed of a light-shielding material (for example, a metal strip) on the base 44a having the window 45 through which the laser beam LC is transmitted. The door panel 44b is composed of two shutter pieces, and each of the shutters is separated from the center line of the window 45 by the shutter driving portion 55 in the direction (X direction) and the vertical direction (Y direction) in which the laser beam LC is scanned. Any arbitrary moving distance Wo' of each sliding equal to 0 can be adjusted to the opening width Wo (wherein the opening width Wo = Wo'*2).

Fig. 6 is a side view showing the positional relationship with the shutter 44 when the mother substrate A on which the coating film region C is formed is irradiated with the laser light. Fig. 7 is a plan view showing the positional relationship with the shutter 44 when the mother substrate A on which the coating film region C is formed is irradiated with the laser light. The opening width Wo of the shutter 44b adjusts the distance between the shutter 44b and the beam spot formed on the mother substrate A based on the shortest distance from the predetermined line S to the coating film region C or the edge C1. For example, as shown in FIG. 6, the opening width Wo of the shutter plate 44b is adjusted so that one portion of the beam spot LD is not irradiated to the region of the coating film region C formed of the transparent conductive film formed on the mother substrate A. Thereby, the center of the beam spot on the mother substrate A is located on the scribe line S, and the beam spot LD whose beam width is limited can be formed.

In addition, in FIG. 6, the position of the shutter 44 is shown only by the shutter 44b for the simplification of a figure.

The operation of the above-described laser scribing device LS1 will be described below with reference to Figs. 1 and 2 .

First, the size of the mother substrate A which is divided into a predetermined size, the formation position of the scribe line (i.e., the scribe line S), and the pressure contact force (line load) of the scribing wheel 18 on the mother substrate A are input.

The position at which the scribe line is formed is set by one pair of cameras 20 (21), and is attached to one of the pair of mother substrates A, and the positioning of the slide table 2 and the pedestal 12 is performed based on image processing. The method of performing such positioning is a well-known technique, such as Japanese Patent No. 3078668, and the detailed description is omitted.

Thereafter, the shortest distance from the scribe line S to the coating film region C or the substrate edge M1 set in advance from the distance input unit 57 is input as the distance data.

The distance data recording unit 59 records the distance data input to the distance data input unit 57, reads the distance data recorded in the distance data recording unit 59, and determines the limit beam spot width W to adjust the shutter plate 44b based on the read distance data. Opening width Wo.

Further, the distance data recorded in the distance from the data recording unit 59 may be the shortest distance per one predetermined line S, or may be the smallest shortest distance available from one mother substrate.

Thereafter, the opening width Wo of the shutter 44b is set such that the long axis of the beam spot LD is superposed on the predetermined line S of the scribe line and as illustrated in FIGS. 6 and 7, one portion of the laser beam is not irradiated to the predetermined line S. The vicinity of the coating film area C. The mother substrate A is then fixed to a predetermined position on the rotary table 12.

Thereafter, the adjustment mechanism 17 is moved upward and downward to form an initial crack. When the scribing wheel 18 is lowered, the mother substrate A is moved to form an initial crack at the substrate end.

The laser oscillator 13 and the cooling nozzle 16 are then driven. Then, the beam spot of the laser beam is scanned along the predetermined line S, and the mother substrate A is moved to eject the cooling medium for scribing. At this time, as shown in FIG. 7, the beam spot LC is a limiting beam spot LD in a state where the width of the line in the width direction of the predetermined line S is restricted by the shutter plate 44b of the optical holder 14 (see FIGS. 3 and 4). ) is illuminated. Therefore, it is possible to prevent the heat distribution from being symmetrical to the entire line of the predetermined line S by the reflection or absorption of the coating film region C, so that a straight line with good straightness can be formed.

Moreover, FIG. 8 is a view for explaining a state in which a scribe line is formed along a predetermined line S in the vicinity of the edge M1 of the substrate formed on the mother substrate A.

When the scribe line S is located in the vicinity of the substrate edge M1 of the mother substrate A, as shown in the figure, one portion (hatched portion) of the beam spot LC is irradiated to the outside of the mother substrate A. At this time, the irradiation adjusts the opening width Wo of the adjustment shutter plate 44b so as to be shorter than the interval d1 between the planned line S of the scribe line and the edge M1 of the substrate, and the interval d2 between the predetermined line S of the scribe line and the coating film area C. The left and right symmetrical limit point width W (that is, the width of the point which is twice the shorter of d1 or d2) limits the beam spot LD.

In addition, although FIG. 5 illustrates a configuration in which the shutter 44 composed of two flaps is used as a shutter member, the shutter member is not limited to such a configuration, and the shape, moving direction, and sheet of the shutter are not limited. The number is variable, and a well-known technique can be applied.

(Embodiment 2)

Fig. 9 is a view showing the schematic configuration of a laser scribing device LS2 according to another embodiment of the present invention. Fig. 10 is a view showing the configuration of a control system of the laser scribing device LS2 of Fig. 9. The same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and the description of the common portions will be omitted.

The laser scribing device LS2 has a basic structure of the above-described laser scribing device LS1, and has a predetermined line S set on the substrate A as the center of the imaging region and reflects the substrate A along the predetermined line S of the scribe line. Surface camera 61. The camera 61 is supported by the robot arm 24 so as to be freely movable. The robot arm 24 is controlled by the camera drive unit 63 shown in FIG. The camera 61 is optimally used from an infrared camera, an optical camera (visible light camera), an X-ray camera or the like in accordance with the type of the coating film so that the coating film region formed on the substrate A can be extracted.

Further, the control unit 56 of the laser scribing device LS2 includes the image information identification pattern captured by the camera 61, and extracts the shortest distance from the predetermined line S to the coating film region C or the substrate edge M1, based on the extraction. The shortest distance determines the beam width expansion width of the beam line in the width direction of the predetermined line to adjust the door width control portion 62 of the opening width Wo of the shutter 44b.

The operation of the door width control unit 62 will be described with reference to Fig. 11 .

Fig. 11 (a to g) is a series of images of the image information captured when the camera 61 is scanned along a predetermined line S of the scribe line.

Each of the imaging regions is formed by a rectangular region formed by a short side extending in a direction orthogonal to the predetermined line S, and a short side extending in a direction parallel to the predetermined line S, and the length of the long side is set to a dot width. The dot width of the light beam before the restriction is set such that the center point O of the photographing area of the camera is the center position coordinate (X ₀ , Y ₀ ) of the camera, and the travel line of the camera 61 is set such that the Y axis overlaps the predetermined line S. Further, the substrate A has a square shape, and a predetermined line is formed in a direction perpendicular to one side S _x1 and its opposite side S _xn .

First, as shown in FIG. 11(a), the X-axis of the imaging area of the camera 61 is overlapped with one side _Sx1 of the substrate A set to be parallel to the X-axis, and the imaging start point is set so that the center point O of the imaging area is It overlaps with one end So of the predetermined line of the scribe line.

The camera 61 is caused to travel along a predetermined line S of the scribe line and as shown in FIG. 11(g), the X-axis of the photographing area of the camera 61 is moved to the other side S _xn of the substrate A set to be parallel to the X-axis. The overlapping shooting end point Se.

Based on the image obtained by the traveling, the coating film on the left and right of the predetermined line S is recognized by a known pattern, and the left side of the planned line S and the right side of the predetermined line S are respectively calculated from the predetermined line S to the package. The shortest distance of the film. For example, the shortest distance dL (Fig. 11 (d)) of the coating film to the left of the scribe line S is calculated and the shortest distance dR to the coating film on the right side of the scribe line S (Fig. 11 (f )) and make it a distance record. Thereafter, the minimum value is compared between the two, and the limit point width W of the predetermined line S of the scribe line photographed by the camera 61 is determined based on the minimum value. Thereafter, the determined limit point width W is input to the relationship between the shape and size of the laser beam input in advance and the distance from the mother substrate A to the shutter 44, and the opening width Wo of the shutter 44b is calculated. Thereby, the opening width Wo of the shutter panel 44b can be automatically determined and then scribed.

In the second embodiment, the door width control unit 62 recognizes the coating film located in the vicinity of the predetermined line S based on the image information pattern to be imaged, and calculates the shortest distance from the predetermined line S to the coating film. The opening width Wo of the shutter 44b is similar to that of the substrate edge instead of the cover film.

In the second embodiment, the shortest distance from the planned line S to the coating film area C or the edge M1 of the substrate is extracted based on the image information pattern recognition by the camera 61, and the shutter panel 44b is adjusted based on the shortest distance of the extraction. The opening width Wo is constituted, but the use of the camera 61 is not limited to the above. For example, as described in the first embodiment, the shortest distance from the predetermined line S to the coating film area C or the substrate edge M1 can be input as the distance data, and the distance data based on the recording is based on the camera 61. Both of the distance data obtained by the captured image information pattern are adjusted to adjust the opening width Wo of the shutter 44b.

Further, in the second embodiment, the laser scribing device LS2 includes one of the positions for forming the alignment marks attached to one of the mother substrates A to obtain the respective scribe lines on the mother substrate A, and the CCD camera 20 (21). The camera 61 is photographed along the line S of the scribe line to adjust the opening width Wo of the shutter 44b. However, the camera unit of the one or two cameras may also be used.

(Embodiment 3)

In the above-described first to second embodiments, the irradiation area adjustment means is attached to the side of the laser scribing apparatus, and the heat distribution of the substrate A centering on the predetermined line after the laser irradiation is bilaterally symmetrical, and in the present embodiment, The irradiation area adjusting means is attached to the side of the substrate A so as to adjust the heat distribution of the substrate A which is a predetermined line of the scribe line after the laser irradiation to be bilaterally symmetrical.

Fig. 12 is a view for explaining a scribing method in which an irradiation area adjusting means is attached to a substrate A side of the present invention. In this example, a coating film region C is formed in a region of the mother substrate A (mother substrate) which becomes the unit display substrate U.

Further, the temporary coating film 71 is formed in advance so that the interval d1 between the planned line S of the scribe line and the edge C1 of the coating film region C and the interval D between the predetermined line S of the scribe line and the temporary coating film 71 (hereinafter referred to as The "temporary coating film interval" is equidistant.

When the unit display substrate U is cut out from the mother substrate A, the mother substrate A is set to a laser scribing device (for example, the laser scribing device LS1 described with reference to FIG. 1) to illuminate the laser beam. In this case, the beam spot LE may have a shape that is bilaterally symmetrical about the line S of the scribe line. In other words, when one portion of the beam spot LE is reflected in the coating film region C, since it is also reflected on the side of the temporary coating film 71, it can be made to be thermally symmetrical about the predetermined line S of the scribe line. distributed.

Fig. 13 is a view showing an example of a temporary coating film which is patterned. C1, C2, C3, and C4 are coating film regions, and 72, 73, 74, and 75 are temporary coating films corresponding to the coating film regions. For convenience of description, the coating film region is displayed in various shapes, but may have the same shape, a simple shape, or the like.

Each of the temporary coating film intervals is equal to the interval between the predetermined line S of the scribe line and the edge of each of the coating film regions. In addition, the shape of the temporary coating film may correspond to the shape of the peripheral portion of the coating film region C close to the predetermined line S of the scribe line, and may correspond to the predetermined line S of the scribe line. The width of the temporary coating film is set as long as the dot width (width width) corresponding to the beam spot LE is set, for example, in the region 76 on the side opposite to the predetermined line S of the scribe line across the temporary coating film 71 in FIG. The range to be illuminated is sufficient.

The formation of the temporary coating film may be performed simultaneously with the formation of the coating film region C, or may be performed on the substrate on which the coating film region C has been formed, or before the coating film region C is formed.

When the temporary coating film 71 made of a transparent conductive film of the same material as the coating film region C is formed, the temporary coating film 71 can be formed at the same time when the coating film region C is formed, so that it can be manufactured. Process simplification.

[Examples]

Specific examples of the embodiments of the present invention will be described below.

(Experiment 1)

The glass substrate on which the transparent conductive film (ITO film) was formed was used to adjust the opening width Wo of the shutter using the laser scribing device LS1 of the present invention, and the results were compared. The experimental conditions are as follows.

Substrate specifications: material is alkali-free glass, thickness is 0.5mm

Beam point shape: ellipse

Marking speed: 200mm/sec

Door: When the light is blocked, the opening width Wo is 0.4mm (the beam width W is limited to 0.4mm), and the height (the height from the glass surface) is 3mm.

(Experiment 2)

The substrate on which the transparent conductive film (ITO film) is formed is scribed at a position where the predetermined line is symmetrical, and the substrate on which the temporary coating film of the present invention is formed and the substrate on which the substrate is formed are compared. The experimental conditions are as follows.

Substrate specifications: material is alkali-free glass, thickness is 0.5mm

Beam point shape: ellipse

Marking speed: 200mm/sec

Temporary coating film: made of reflective aluminum tape

The results of arranging these experiments are as follows. In either case, the positional deviation of the scribe line is greatly reduced by the point-symmetric illumination of the beam, and the straightness of the scribe line is improved.

Further, in the above-described first to second embodiments, the elliptical beam spot is used. However, the shape of the beam spot in the present invention is not particularly limited as long as it is symmetrical with respect to the left-right direction of the predetermined line of the scribe line.

Further, although the glass substrate is used as a target for scribing, the object to be processed is not limited to the glass substrate.

The laser scribing method and the laser scribing apparatus of the present invention can be applied to ceramics of glass, sintered materials, single crystal germanium, semiconductor wafers, ceramic substrates, sapphire substrates, liquid crystal display substrates in which glass substrates are bonded to each other, A scribed line of a transmissive liquid crystal display substrate, an organic EL element substrate, a PDP substrate, and a reflective liquid crystal display substrate in which a glass substrate and a ruthenium substrate are bonded together is formed.

2‧‧‧ sliding platform

12‧‧‧Rotating platform

13‧‧‧Laser oscillator

14‧‧‧Optical holder

16‧‧‧Cooling nozzle

18‧‧‧marking wheel

41‧‧‧Optical segmentation components

42, 43‧‧‧ concentrating lens

44‧‧ ‧ blocking

44b‧‧‧ door panel

51‧‧‧ Platform Drive Department

52‧‧‧ Laser Drive Department

53‧‧‧Nozzle Drive Department

54‧‧‧Cutter drive department

55‧‧‧Door drive unit

56‧‧‧Control Department

57‧‧‧ Input Department

58‧‧‧Display Department

59‧‧‧Distance data recording department

61‧‧‧ camera

62‧‧‧Door width control

71~75‧‧‧ temporary coating film

A‧‧‧glass substrate (mother substrate)

C‧‧‧coated film area

D‧‧‧Interim coating film interval

LD‧‧‧Limited beam spot

Wo‧‧‧ opening width

W‧‧‧Limit beam spot width

Fig. 1 is a schematic block diagram showing a laser scribing apparatus according to an embodiment of the present invention.

Fig. 2 is a view showing the configuration of a control system of the laser scribing apparatus of Fig. 1.

Figure 3 is a diagram illustrating an optical holder forming a beam spot.

Fig. 4 is a view showing another example of an optical holder for forming a beam spot.

Fig. 5 is a schematic block diagram showing the configuration of a door.

Fig. 6 is a side view showing the positional relationship with the shutter when the glass substrate on which the coating film region is formed is irradiated with the laser light.

Fig. 7 is a plan view showing the positional relationship with the shutter when the glass substrate on which the coating film region is formed is irradiated with the laser light.

Fig. 8 is a view for explaining a state in which a scribe line is formed along a line near the edge of the substrate formed on the glass substrate.

Fig. 9 is a schematic block diagram showing a laser scribing apparatus according to another embodiment of the present invention.

Fig. 10 is a view showing the configuration of a control system of the laser scribing apparatus of Fig. 9.

Fig. 11 is a view showing a continuous image of a laser scribing apparatus according to still another embodiment of the present invention taken along a predetermined line S of a scribe line.

Fig. 12 is a view for explaining a laser scribing method according to another embodiment of the present invention.

Fig. 13 is a view showing an example of a coating film region and a temporary coating film to be patterned.

Fig. 14 is a view showing a scribe line formed by scanning a beam spot along a predetermined line on a mother substrate formed on a mother substrate in the vicinity of a predetermined line of a scribe line in a conventional technique.

15 is a scribe line which is formed when a beam spot is scanned along a predetermined line of a scribe line on a mother substrate on which a predetermined line is formed at a position where the distance from the edge M1 of the substrate is extremely short. Schematic diagram.

13‧‧‧Laser oscillator

14‧‧‧Optical holder

42, 43‧‧‧ concentrating lens

44b‧‧‧ door panel

A‧‧‧glass substrate (mother substrate)

C‧‧‧coated film

C1‧‧‧ edge

LB‧‧‧Laser beam

LC‧‧‧Laser beam

LD‧‧‧Limited beam spot

W‧‧‧Limit beam spot width

Claims (3)

A laser scribing method for a brittle material substrate is performed by moving a laser beam irradiation mechanism relative to a brittle material substrate and irradiating a laser beam to scan a beam spot of a laser beam along a predetermined line of a scribe line to heat the substrate, and then borrowing The substrate is cooled by a predetermined line along the scribe line to form a scribe line along a predetermined line of the scribe line, and is characterized in that the irradiation area is shielded from the surface of the substrate on which the laser light is irradiated to the predetermined line of the scribe line. The adjustment means is mounted on the surface of the substrate to irradiate the laser beam to a region where the surface of the substrate on which the laser light is irradiated is asymmetric with respect to the area where the predetermined line of the scribe line is asymmetrical. The laser scribing method according to claim 1, wherein the irradiation area adjusting means attached to the brittle material substrate is formed on the opposite side of the coating film region near the predetermined line along the scribe line by a predetermined line along the scribe line. The temporary coating film is formed. The laser scribing method according to claim 1, wherein the brittle material substrate forms a coating film region on one of the surface of the substrate, and the coating film region is provided at one of the scanned beam spots. The location of the coating film area.