JP2008100257A - Scribing apparatus, method for parting substrate, and method for producing electrooptical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scribing apparatus by which, when laser scribing is performed, a modified part can be formed at high productivity, to provide a method for parting a substrate, and to provide a method for producing an electrooptical device. <P>SOLUTION: The invention refers to a scribing apparatus by which a substrate 41 is irradiated with laser light 37 so as to be scribed, and a method for parting the substrate. The scribing apparatus is provided with: a laser light source for emitting the laser light 37; and a light collecting part 8 where the laser light 37 is collected on the inside of the substrate 41 so as to be emitted, and a modified part 45 is formed. The light collecting part 8 performs light collection in such a manner that, compared with a first direction 38 orthogonal to the optical axis of the laser light 37, in a second direction 39 orthogonal to the optical axis and the first direction 38, the number of apertures in the laser light 37 is made large, and the substrate 41 is irradiated with the light. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a scribing apparatus, a method for dividing a substrate, and a method for manufacturing an electro-optical device.

Patent Document 1 discloses a laser scribing method in which a modified region (hereinafter referred to as a modified portion) is formed inside a substrate by irradiating the substrate with laser light in order to cut a light transmissive substrate with high quality. ing. According to this, a laser beam having a pulse width of 1 μs or less is emitted and condensed inside the substrate by a condenser lens, and the peak power density in the condensing part is set to 1 × 10 ⁸ (W / cm ² ) or more. Thereby, the modified part by multiphoton absorption is formed inside the workpiece.

In this laser scribing method, the size of the modified portion formed inside the object to be processed or the modified portion formed from this depends on the characteristics of the condenser lens and the peak power density of the laser beam. Dependent. For example, in an embodiment in which the glass (thickness: 700 μm) disclosed in Patent Document 1 is cut using a YAG laser, the peak power density is approximately 1 × when the condensing lens has a numerical aperture of 0.55. At 10 ¹¹ (W / cm ² ), the size of the modified portion is approximately 100 μm. Further, when the peak power density is about 5 × 10 ¹¹ (W / cm ² ), it is about 250 μm. By forming the reforming portions in the substrate and pressing the reforming portions, the substrate can be divided along the reforming portions with good quality.

JP 2002-192371 A

  In order to cut the substrate with high quality, the modified portions are arranged and formed inside the substrate. When the glass is thick, it is necessary to arrange a plurality of modified portions in the thickness direction. Since a large number of reforming portions are required when the substrate is large, a method for forming the reforming portions with high productivity has been desired.

  The present invention has been made paying attention to such conventional problems, and provides a scribing device, a substrate cutting method, and an electro-optical device manufacturing method that can form a modified portion with high productivity when laser scribing. The purpose is to provide.

  In order to solve the above problems, a scribing apparatus of the present invention is a scribing apparatus that irradiates a substrate with laser light and scribes the laser light source that emits laser light, and condenses the laser light inside the substrate. And a condensing part that forms a modified part, and the condensing part is in a second direction orthogonal to the optical axis and the first direction, compared to a first direction orthogonal to the optical axis of the laser beam. The laser beam is condensed so as to increase the numerical aperture of the laser beam and irradiated onto the substrate.

Here, irradiating the substrate with laser light and scribing means irradiating the substrate with laser light, arranging the modified portions, and along the modified portions formed by arranging the substrates. The manufacturing method for making the substrate easy to be divided will be described.
The numerical aperture is a luminous flux that enters or exits the optical system and indicates the sine value of the angle formed by the most peripheral light beam and the optical axis.

  According to this scribing apparatus, the scribing apparatus includes a laser light source and a condensing unit. A laser light source emits laser light. A condensing part condenses and irradiates a laser beam inside a board | substrate. The condensing unit condenses on the substrate so that the numerical aperture of the laser light is larger in the second direction perpendicular to the optical axis and the first direction than in the first direction perpendicular to the optical axis of the laser light. Irradiate.

  A modified portion is formed in a place where the laser beam is focused on the substrate. Since the numerical aperture of the laser beam is larger in the second direction than in the first direction, the formed modified portion has a shape that is longer in the first direction than in the second direction. That is, a reforming portion that is long in the first direction can be formed. Therefore, when arranging the modified portions side by side on a substrate having a predetermined length, the modified portions can be formed with a smaller number of irradiation than when the modified portions having the same length are formed in the first direction and the second direction. Can be arranged. As a result, it is possible to scribe with high productivity.

  In the scribing apparatus of the present invention, the light condensing unit includes an objective lens, and the objective lens is an aspheric lens having a short focal length in the second direction with respect to the focal length in the first direction.

  According to this scribing apparatus, the scribing apparatus includes the objective lens. This objective lens is an aspheric lens, and is formed such that the focal length in the second direction is shorter than the focal length in the first direction. Therefore, the numerical aperture of the laser light passing through the objective lens can be increased in the second direction compared to the first direction. As a result, a modified portion that is long in the first direction can be formed on the substrate on which the laser light is collected and irradiated using this objective lens.

  In the scribing apparatus of the present invention, the objective lens is a columnar lens.

  According to this scribing apparatus, the scribing apparatus includes an objective lens, and the objective lens is a columnar lens. In the columnar lens, one direction of the cross section is formed by a curve, and another direction is formed by a straight line. When forming all directions in a curved line with respect to the optical axis of the lens, it is necessary to polish the entire direction to form a curved line. On the other hand, when one direction of the lens is a straight line, it can be said that the lens is easy to form because it can be polished in one direction to form a curve. Therefore, a scribing apparatus including an objective lens that can be formed with high productivity can be obtained.

  The scribing device of the present invention is characterized in that the condensing unit rotates around the optical axis, and the first direction and the second direction are changed.

  According to this scribing device, the scribing device includes the light collecting unit, and the first direction and the second direction are changed as the light collecting unit rotates about the optical axis. A modified portion that is long in the first direction can be formed on the substrate that condenses and irradiates laser light using this condensing portion. Therefore, by changing the first direction and the second direction, the first direction in which the reforming portion is formed longer can be set to a desired direction. As a result, it is possible to form a modified portion that is long in a desired direction.

  In order to solve the above-described problems, the substrate dividing method of the present invention is a method for dividing a substrate in which a substrate that transmits visible light is irradiated with laser light from a light converging unit, a modified portion is formed, and the substrate is divided. Irradiation that condenses and irradiates the substrate in a second direction orthogonal to the optical axis and the first direction so that the numerical aperture of the laser light is larger than that in the first direction orthogonal to the optical axis of the laser light. A process, a moving process for relatively moving the substrate and the light collecting unit in the first direction, and a dividing process for pressing and dividing the substrate, and repeating the irradiation process and the moving process in the first direction. The modification part is arranged and scribed.

According to the method for dividing a substrate, the substrate that transmits visible light is irradiated with laser light from a light collecting unit to form a modified unit, a moving step, and a dividing step.
In the irradiation process, the laser beam is condensed and irradiated on the substrate in a second direction orthogonal to the optical axis and the first direction as compared with the first direction orthogonal to the optical axis of the laser light. To do. In the moving step, the substrate and the light collecting unit are relatively moved in the first direction. The irradiation process and the moving process are repeated, and the modified portions are arranged and scribed in the first direction. Subsequently, in the dividing step, the substrate is pressed and divided.

  In the irradiation step, the numerical aperture of the laser beam to be irradiated is larger in the second direction than in the first direction, so that the formed modified portion has a shape longer in the first direction than in the second direction. . That is, a reforming portion that is long in the first direction can be formed. In the moving step, the substrate and the light collecting unit are relatively moved in the first direction. By repeating the irradiation step and the moving step, the modified portions that are long in the first direction can be formed by being arranged in the first direction. Therefore, when arranging the modified portions side by side on a substrate having a predetermined length, the modified portions can be formed with a smaller number of irradiation than when the modified portions having the same length are formed in the first direction and the second direction. Can be arranged. As a result, it is possible to scribe with high productivity.

  In order to solve the above problems, a method for manufacturing an electro-optical device according to the present invention is a method for manufacturing an electro-optical device in which an optical element is sandwiched and formed between a first substrate and a second substrate. A first scribing step for scribing a first mother substrate in which the first substrate is formed in a plurality of rows and columns, and a second scribing step for scribing a second mother substrate in which the second substrate is formed in a plurality of rows and columns. And a dividing step of dividing the first mother substrate and the second mother substrate, and in at least one of the first scribe step and the second scribe step, the first mother substrate or the first mother substrate 2 Mother substrate is irradiated with laser light from the condensing part, a modified part is formed, and a scribing process for scribing is included. The scribing process includes an irradiation process and a moving process. Compared with the first direction orthogonal to the optical axis, the laser beam is condensed so as to increase the numerical aperture of the laser beam in the second direction orthogonal to the optical axis and the first direction. In the scribing process, the irradiation process and the moving process are repeated, and the modification parts are arranged in the first direction for scribing.

  According to this method for manufacturing an electro-optical device, the electro-optical device is formed by bonding an optical element between a first substrate and a second substrate. The method for manufacturing an electro-optical device includes a first scribe process, a second scribe process, and a dividing process. In the first scribing step, the first mother substrate on which the first substrate is formed in a plurality of rows and a plurality of columns is scribed. In the second scribing step, the second mother substrate in which the second substrate is formed in a plurality of rows and a plurality of columns is scribed. In the dividing step, the first mother substrate and the second mother substrate are divided. At least one of the first scribe step and the second scribe step is used to scribe one or both of the first mother substrate and the second mother substrate using laser light.

  And the scribing method using this laser beam has an irradiation process and a movement process. In the irradiating step, the substrate is condensed so that the numerical aperture of the laser light is larger in the second direction perpendicular to the optical axis and the first direction than in the first direction perpendicular to the optical axis of the laser light. Irradiate. In the moving step, the substrate and the light collecting unit are relatively moved in the first direction. The irradiation process and the moving process are repeated, and the modified portions are arranged in the first direction to perform scribing.

  In the irradiation step, the numerical aperture of the laser beam to be irradiated is larger in the second direction than in the first direction, so that the formed modified portion has a shape longer in the first direction than in the second direction. . That is, a reforming portion that is long in the first direction can be formed. In the moving step, the substrate and the light collecting unit are relatively moved in the first direction. By repeating the irradiation step and the moving step, the modified portions that are long in the first direction can be formed by being arranged in the first direction. Therefore, when arranging the modified portions side by side on a substrate having a predetermined length, the modified portions can be formed with a smaller number of irradiation than when the modified portions having the same length are formed in the first direction and the second direction. Can be arranged. As a result, it is possible to scribe with high productivity.

Embodiments of the present invention will be described below with reference to the drawings.
In addition, each member in each drawing is illustrated with a different scale for each member in order to make the size recognizable on each drawing.

(First embodiment)
In the present embodiment, an example will be described in which a scribing device having a columnar lens as an objective lens is used for scribing and dividing by a laser scribing method. Here, the scribing apparatus will be described with reference to FIGS. 1 and 2 before describing the characteristic manufacturing method of the present invention.

(Scribe device)
FIG. 1 is a schematic schematic diagram showing the configuration of the scribing apparatus, and FIG. 2 is a schematic schematic diagram of the main part showing the configuration of the light collecting unit.
As shown in FIG. 1, the scribing apparatus 1 includes a laser light source 2 that emits laser light, an optical path portion 3 that irradiates the work with the emitted laser light, and a workpiece that is relatively relative to the optical path portion 3. The table 4 to be moved and the control device 5 for controlling the operation are mainly configured.

The laser light source 2 may be any light source that can collect the emitted laser light inside the object to be processed and form a modified portion by multiphoton absorption. For example, in the present embodiment, the laser light source 2 is composed of a laser medium of LD excitation Nd: YAG (Nd: Y ₃ Al ₅ O ₁₂ ), and is a third harmonic (wavelength: 355 nm) Q-switch pulse oscillation laser light. The light emission conditions for emitting light are employed. The light emission conditions for emitting a laser beam with a pulse width of about 14 ns (nanoseconds), a pulse period of 10 kHz, and an output of about 60 μJ / pulse are employed.

  The optical path unit 3 includes a half mirror 6. The half mirror 6 is disposed on the optical axis 7 a of the laser light emitted from the laser light source 2. The half mirror 6 reflects the laser light emitted from the laser light source 2 and changes the traveling direction from the optical axis 7 a to the optical axis 7. A condenser 8 is disposed on the optical axis 7 through which the laser light reflected by the half mirror 6 passes. A work 9 as a substrate is disposed on the table unit 4, and the work 9 is irradiated with laser light that has passed through the light collecting unit 8.

  The condensing unit 8 is supported by the lens moving mechanism 11 by the lens support unit 10. The lens moving mechanism 11 has a linear motion mechanism (not shown), moves the condensing unit 8 in the direction of the optical axis 7 (Z direction in the figure), and determines the position where the laser light that has passed through the condensing unit 8 is condensed. It can be moved.

  The linear motion mechanism is, for example, a screw type linear motion mechanism provided with a screw shaft (drive shaft) extending in the Z direction and a ball nut screwed to the screw shaft, and the drive shaft receives a predetermined pulse signal. It is connected to a Z-axis motor (not shown) that rotates forward and backward in predetermined step units. When a drive signal corresponding to a predetermined number of steps is input to the Z-axis motor, the Z-axis motor rotates normally or reversely, and the lens moving mechanism 11 corresponds to the number of steps corresponding to the optical axis 7 direction. It moves forward or backward along.

  The condensing unit 8 includes a condensing lens 8 a as a columnar objective lens and a lens rotating mechanism 12. The lens rotation mechanism 12 can rotate the condenser lens 8 a about the optical axis 7.

  An imaging device 13 is provided on the extension line of the optical axis 7 that passes through the light collector 8 and the half mirror 6, on the opposite side of the light collector 8 with respect to the half mirror 6. For example, the imaging device 13 includes a coaxial incident light source (not shown) and a CCD (Charge Coupled Device). Visible light emitted from the coaxial incident light source passes through the condensing unit 8 and irradiates the work 9. The imaging device 13 can image the workpiece 9 through the light collecting unit 8 and the half mirror 6.

  The table unit 4 includes a base 15. On the side of the optical path portion 3 of the base 15, a rail 16 is provided so as to protrude, and an X-axis slide 17 is provided on the rail 16. The X-axis slide 17 includes a linear motion mechanism (not shown) and can move in the X direction on the rail 16. The linear motion mechanism is a mechanism similar to the linear motion mechanism included in the lens moving mechanism 11, and the X-axis slide 17 corresponds to the number of steps corresponding to the drive signal corresponding to the predetermined number of steps in the X direction. It moves forward or backward along.

  A rail 18 is provided so as to protrude from the X-axis slide 17 on the optical path section 3 side, and a Y-axis slide 19 is provided on the rail 18. The Y-axis slide 19 includes a linear motion mechanism similar to that of the X-axis slide 17 and can move on the rail 18 in the Y direction.

  A stage 20 is disposed on the optical path section 3 side of the Y-axis slide 19, and a suction chuck mechanism (not shown) is provided on the upper surface of the stage 20. When the workpiece 9 is placed, the workpiece 9 is positioned and fixed at a predetermined position on the upper surface of the stage 20 by the chuck mechanism.

The control device 5 includes a main computer 24. The main computer 24 includes a CPU (Central Processing Unit) and a memory (not shown). The CPU controls the operation of the scribe device 1 according to program software stored in the memory.
The main computer 24 includes an input / output interface (not shown), and is connected to an input device 25, a display device 26, a laser control device 27, a lens control device 28, an image processing device 29, and a stage control device 30.

  The input device 25 is a device for inputting data of various processing conditions used in laser processing, and the display device 26 is a device for displaying various information at the time of laser processing. The CPU performs laser processing according to various processing conditions and program software that are input, and displays the processing status on the display device 26. The operator looks at various information displayed on the display device 26 and confirms the laser processing status for operation.

  The laser control device 27 is a device that controls the pulse width of the pulse signal that drives the laser light source 2, the pulse cycle, the start and stop of output, and the like, and is controlled by the control signal of the main computer 24.

  The lens control device 28 is a device that controls the movement and stop of the lens moving mechanism 11 and the rotation angle of the condenser lens 8a. The lens moving mechanism 11 has a built-in position sensor (not shown) capable of detecting the moving distance, and the lens control device 28 detects the output of the position sensor to detect the position of the light collecting unit 8 in the direction of the optical axis 7. Recognize position. The lens control device 28 can transmit a pulse signal to the lens moving mechanism 11 to move the lens moving mechanism 11 to a desired position.

  The condensing unit 8 incorporates an angle sensor (not shown) that can detect the rotation angle of the condensing lens 8a, and the lens control device 28 detects the angle of the condensing lens 8a by detecting the output of the angle sensor. Recognize The lens control device 28 can transmit a drive signal to the lens rotation mechanism 12 to rotate the condenser lens 8a to a desired angle and stop it.

  The image processing device 29 has a function of calculating image data output from the imaging device 13. When the work 9 is placed on the stage 20 and an image picked up by the image pickup device 13 is observed, the image is sharpened by operating the lens moving mechanism 11 and changing the distance between the light condensing unit 8 and the work 9. There are times when it is blurred. When the condensing unit 8 is moved to focus on the surface of the work 9 on the stage 20 side and when the work 9 is focused on the surface of the work 9 on the optical path unit 3 side, the captured image becomes clear. On the other hand, when the image is out of focus, the captured image is a blurred image.

  The thickness of the work 9 is measured by moving the condensing unit 8 in the direction of the optical axis 7 and detecting the position of the condensing unit 8 at which the image picked up by the imaging device 13 becomes clear by a built-in position sensor. It becomes possible to do.

  The in-focus position is obtained by measuring the distance between the in-focus position where the image is focused by the imaging device 13 and the condensing position where the light is condensed by the condensing unit 8 when the laser beam is irradiated. And the offset distance, which is the difference between the condensing positions. For example, an object in which two transparent substrates are stacked is placed on the stage 20 as a work 9, and the light condensing unit 8 is moved so that the imaging device 13 is focused on a contact portion between the two substrates. Next, the modified portion is formed by irradiating laser light. The offset distance can be set by measuring the distance between the contact portion and the reforming portion of the two substrates.

  The condensing unit 8 is moved in the direction of the optical axis 7 (Z direction in the figure), and the imaging device 13 is focused on the surface of the work 9 on the optical path unit 3 side. Using the data of the position where the laser beam is to be irradiated and the offset distance, the moving distance of the condensing unit 8 is calculated, and the condensing unit 8 is moved by the distance corresponding to the calculated moving distance. With this method, the laser beam can be condensed to a predetermined depth in the workpiece 9.

  The stage control device 30 performs acquisition of position information and movement control of the X-axis slide 17 and the Y-axis slide 19. The X-axis slide 17 and the Y-axis slide 19 have built-in position sensors (not shown), and the stage control device 30 detects the positions of the X-axis slide 17 and the Y-axis slide 19 by detecting the output of the position sensor. To detect. The stage control device 30 acquires the position information of the X-axis slide 17 and the Y-axis slide 19, compares the position information instructed from the main computer 24, and corresponds to the distance corresponding to the difference to the X-axis slide. 17 and the Y-axis slide 19 are driven to move. The stage control device 30 can drive the X-axis slide 17 and the Y-axis slide 19 to move the workpiece 9 to a desired position.

  The laser control device 27 controls the laser light source 2 to emit laser light. The image processing device 29 detects the position in the direction of the optical axis 7 on the surface of the workpiece 9. The lens control device 28 controls the position in the direction of the optical axis 7 where the laser light is condensed. The stage control device 30 moves the workpiece 9 in the XY directions, and controls the position where the workpiece 9 is irradiated with laser light. It is possible to collect and irradiate laser light at a desired position by performing the above-described control.

  Here, formation of the modified portion by multiphoton absorption will be described. The laser beam condensed by the condensing unit 8 enters the workpiece 9. Even if the workpiece 9 is a material that transmits laser light, the workpiece 9 absorbs photon energy when the energy of the photon is much larger than the absorption band gap of the material. This is called multiphoton absorption. When the energy is increased by making the pulse width of the laser light extremely short and the multiphoton absorption is caused inside the work 9, the energy of the multiphoton absorption is not converted into thermal energy. A region in which a permanent structural change is induced is formed.

  In the present embodiment, this structure change region is called a modified portion. Of the modified portion, a region where a plurality of cracks are formed as a result of a large structural change is referred to as a crack portion. Depending on the type of material, for example, in the case of quartz or the like, the crack portion may not be a plurality of cracks, and a cavity may be formed.

  As for the irradiation condition of the laser beam for forming such a modified portion, it is necessary to set the output of the laser beam, the pulse width, the pulse period, the laser scan speed, etc. for each workpiece. In particular, it is necessary to consider that the output of the laser light emitted from the laser light source 2 is attenuated by absorption by a transmissive substance disposed on the optical axis 7 such as the half mirror 6 or the light collecting unit 8. Therefore, it is desirable to carry out a preliminary test using an actual workpiece to derive optimum irradiation conditions.

  FIG. 2A is a schematic plan view of a main part showing the light collecting unit 8. 2B is a schematic cross-sectional view of the main part taken along the line AA ′ in FIG. 2A, and FIG. 2C is a schematic cross-sectional view of the main part taken along the line BB ′ in FIG. FIG.

  As shown in FIG. 2A, the light collecting unit 8 includes a cylindrical fixed tube 31 connected to the lens support unit 10. A moving tube 33 is disposed inside the fixed tube 31 via a ball 32. A ball bearing is formed by the fixed tube 31, the ball 32, and the moving tube 33, and the moving tube 33 is rotatable.

  A support plate 34 having a rectangular hole is disposed inside the moving tube 33. A condensing lens 8a formed in a rectangular shape is disposed in the rectangular hole. The condensing lens 8a and the moving tube 33 are arranged so that the center of the condensing lens 8a, the center of the moving tube 33, and the optical axis 7 overlap. Thereby, the condensing lens 8a formed in a rectangle is configured such that the center of the rectangle overlaps with the optical axis 7 and rotates around the optical axis 7 as a rotation center.

  The lens support unit 10 is provided with a lens rotation motor 35 in which the drive shaft 35a receives a predetermined pulse signal and rotates forward and backward in a predetermined step unit. A gear 36 is disposed on the drive shaft 35 a, and the outer peripheral portion 36 a of the gear 36 is in contact with the outer peripheral portion 33 a of the moving tube 33. Further, teeth are formed on the outer peripheral portion 33 a of the moving tube 33, and mesh with the teeth formed on the outer peripheral portion 36 a of the gear 36. Therefore, when the gear 36 rotates, the power of the gear 36 is transmitted to the moving tube 33 so that the moving tube 33 rotates.

  When a drive signal corresponding to a predetermined number of steps is input to the lens rotation motor 35, the drive shaft 35a of the lens rotation motor 35 rotates forward or reverse. The rotation of the drive shaft 35a of the lens rotation motor 35 is transmitted to the moving tube 33 via the gear 36, and the moving tube 33 rotates. Since the condensing lens 8a is disposed on the moving tube 33 via the support plate 34, when the moving tube 33 rotates, the condensing lens 8a rotates. That is, when the drive shaft 35a of the lens rotation motor 35 rotates, the condenser lens 8a rotates about the optical axis 7 according to the rotation angle of the drive shaft 35a.

  As shown in FIGS. 2B and 2C, the condensing lens 8a is rectangular when viewed from the AA ′ direction, and is columnar in the form of a convex lens when viewed from the BB ′ direction. It is a lens. When irradiating the condensing lens 8a with the laser light 37 from the Z direction, the condensing lens 8a is not condensed in the X direction but condensed in the Y direction. Therefore, the condensing place 37a which the laser beam 37 condenses becomes a linear shape long in the X direction.

  A direction (X direction) in which the cross section of the condensing lens 8a is rectangular is defined as a first direction 38, and a direction (Y direction) in which the cross section of the condensing lens 8a is a convex lens is defined as a second direction 39. Since the laser light 37 that has passed through the condensing lens 8a is not condensed in the first direction 38, the numerical aperture of the condensing lens 8a in the first direction 38 is close to zero. On the other hand, since the laser light 37 that has passed through the condenser lens 8a is condensed in the second direction 39, the numerical aperture of the condenser lens 8a in the second direction 39 is larger than the numerical aperture in the first direction 38. It is getting bigger.

  Further, since the laser light 37 that has passed through the condenser lens 8a is not condensed in the first direction 38, the focal length of the condenser lens 8a with respect to the first direction 38 becomes an infinite value. On the other hand, since the laser light 37 that has passed through the condensing lens 8a is condensed in the second direction 39, the focal length of the condensing lens 8a in the second direction 39 is a finite value. Therefore, the condensing lens 8 a is an aspherical lens having a shorter focal length in the second direction 39 than the focal length in the first direction 38.

(Substrate dividing method)
Next, the substrate cutting method of the present invention will be described with reference to FIGS. FIG. 3 is a flowchart of the substrate dividing method, and FIGS. 4 to 9 are diagrams for explaining the substrate dividing method.

  In the flowchart of FIG. 3, step S <b> 1 corresponds to a substrate installation process, and is a process of installing a substrate on a scribe device and initializing the scribe device. Next, the process proceeds to step S2. Step S2 corresponds to an irradiation process, and is a process of forming a modified portion by irradiating the substrate with laser light. At this time, the condenser lens is a columnar lens, and irradiation is performed in the second direction of the condenser lens so that the numerical aperture of the laser light is increased. Next, the process proceeds to step S3. Step S3 corresponds to a step of determining whether or not all the planned areas have been irradiated. The area to be scribed is compared with the area to be scribed, and the areas not yet scribed are searched for in the areas to be scribed. It is a process. When there is an area that is not yet scribed in the area to be scribed (NO), the process proceeds to step S4. When there is no area that is not scribed in the area to be scribed (YES), the process proceeds to step S5. Step S4 corresponds to a moving step, and is a step of relatively moving the condenser lens and the table portion to the next scribe area in the first direction of the condenser lens. Next, the process proceeds to step S2.

  Step S5 corresponds to a rotation process, and is a process of rotating the condenser lens and changing the first direction and the second direction of the condenser lens with respect to the substrate. Next, the process proceeds to step S6. Step S6 corresponds to a moving step, and is a step of moving to a region that is scribed in a direction different from the direction scribed in step S2. Next, the process proceeds to step S7. Step S7 corresponds to an irradiation step, and is a step of forming a modified portion by irradiating the substrate with laser light. At this time, the condenser lens is a columnar lens, and irradiation is performed in the second direction of the condenser lens so that the numerical aperture of the laser light is increased. Next, the process proceeds to step S8. Step S8 corresponds to the step of determining whether all the planned areas have been irradiated. The area to be scribed is compared with the area to be scribed, and the areas not yet scribed are searched for in the areas to be scribed. It is a process. If there is an area that is not yet scribed in the area to be scribed (NO), the process proceeds to step S9. When there is no area that is not scribed in the area to be scribed (YES), the process proceeds to step S10. Step S9 corresponds to a moving step, and is a step of relatively moving the condenser lens 8a and the table unit 4 to the next scribe area in the first direction of the condenser lens. Next, the process proceeds to step S7. Steps S1 to S9 are collectively referred to as step S11. Step S11 corresponds to a scribe process.

  Step S10 corresponds to a dividing step, and is a step of dividing the substrate by pressing the scribed place of the substrate. The process of dividing the substrate is completed by the above process.

  Next, the manufacturing method will be described in detail using FIGS. 4 to 9 in association with the steps shown in FIG. FIG. 4A is a schematic plan view of a substrate to be divided in this embodiment. FIG. 4B is a schematic side view of the bonded substrate shown in FIG. 4A as viewed from the line C-C ′. As shown in FIGS. 4A and 4B, the substrate 41 is formed of a rectangular plate. The substrate 41 is made of a material that is transmissive to laser light. In this embodiment, for example, quartz glass is used.

  In the plane direction of the substrate 41, the longitudinal direction of the substrate 41 is defined as the X direction, and the direction orthogonal to the X direction is defined as the Y direction. The thickness direction of the substrate 41 is the Z direction. In the substrate 41, a surface in the thickness direction (Z direction) passing through the center line in the X direction is defined as a first scheduled cutting surface 42. Similarly, in the substrate 41, a surface in the thickness direction (Z direction) passing through the center line in the Y direction is defined as a second scheduled cutting surface 43. The first scheduled cutting surface 42 is a surface to be scribed in steps S2 to S4, and the second scheduled cutting surface 43 is a surface to be scribed in steps S7 to S9.

  FIG. 4C and FIG. 5A are diagrams corresponding to step S1. As shown in FIG. 4C, the substrate 41 is placed on the table unit 4 of the scribing apparatus 1 shown in FIG. The substrate 41 is fixed to the stage 20 by a suction type chuck mechanism. The scribing apparatus 1 moves the condensing unit 8 to a place where the laser light 37 can be irradiated to a place 42 a that is an end of the substrate 41 on the first scheduled cutting surface 42. In this step, the operator sets the light emission conditions of the laser light source 2 that irradiates the laser light 37.

  As shown to Fig.5 (a), it arrange | positions so that the 1st direction 38 from which the cross section of the condensing lens 8a becomes a rectangle may become the same direction as the 1st cutting plan surface 42. FIG. Therefore, the second direction 39 in which the cross-section of the condenser lens 8a is a convex lens is a direction orthogonal to the first scheduled cutting surface 42.

  FIG. 5B and FIG. 5C are diagrams corresponding to step S2. As shown in FIGS. 5B and 5C, the laser beam 37 is condensed in the Y direction and irradiated from the condensing unit 8 to the inside of the substrate 41. A reforming portion 45 is formed at the condensing place 37 a where the laser beam 37 is condensed and irradiated, and a crack portion 46 is formed at the center of the reforming portion 45. In the present embodiment, since quartz glass is used for the substrate 41, a cavity is formed in the crack portion 46.

  Compared with the first direction 38, the laser beam 37 is condensed and irradiated on the substrate 41 in the second direction 39 so that the numerical aperture of the laser light 37 is increased. That is, the condensing lens 8a does not condense the laser light 37 in the first direction 38, but condenses it in the second direction 39, so that the reforming unit 45 is long in the first direction 38 and the second direction. 39 is formed in a short shape.

  Since the first direction 38 is arranged in the direction of the first scheduled cutting surface 42, the reforming portion 45 is formed in a shape that is long along the first scheduled cutting surface 42 and short in the Y direction.

  In step S2, after the laser beam 37 is irradiated, the process proceeds to step S3. In step S <b> 3, the main computer 24 determines whether the reforming portion 45 has been formed on all of the first scheduled cutting surfaces 42. The main computer 24 includes a storage unit. The storage unit stores data on a location where the reforming portion 45 is to be formed and a location where the reforming portion 45 has already been formed on the first cut planned surface 42. In step S2, the main computer 24 stores the data of the place formed in the storage unit every time the reforming unit 45 is formed. It is determined whether or not there is a place where the reforming part 45 is to be formed and the reforming part 45 is not formed. When there is a place where the reforming unit 45 is not formed, the process moves to that place in step S4.

  FIG. 6A is a diagram corresponding to step S4. As shown in FIG. 6A, the substrate 41 and the light collector 8 are relatively moved in the first direction 38. The moving distance is an interval at which the reforming part 45 is formed, and in this embodiment, for example, is a distance slightly shorter than the width of the reforming part 45 in the first direction 38. The interval for forming the reforming portion 45 may be an interval at which the reforming portion 45 is arranged in step S10 so that it can be divided with good quality, and it is desirable to set the interval by trial.

  FIG. 6B and FIG. 6C are diagrams corresponding to step S2. As shown in FIG. 6B, the laser beam 37 is condensed and irradiated in the Y direction from the condensing unit 8 to the inside of the substrate 41. A reforming portion 45 is formed at the condensing place 37 a where the laser beam 37 is condensed and irradiated, and a crack portion 46 is formed at the center of the reforming portion 45. As a result, the reforming portions 45 are formed in an array.

  As shown in FIG. 6C, the reforming portions 45 are arranged and formed to form the first-stage reforming portion 45a. Subsequently, the reforming portions 45 are arranged and formed at positions adjacent to the first-stage reforming portion 45a in the Z direction to form the second-stage reforming portion 45b. In this way, the reforming portions 45 are formed in multiple stages, and the first scribe surface 47 on which the reforming portions 45 are formed is formed on all the first scheduled cutting surfaces 42.

  FIG. 7A corresponds to steps S5 and S6. As shown in FIG. 7A, in step S5, the scribing apparatus 1 rotates the condenser lens 8a around the optical axis 7 of the condenser lens 8a. The first direction 38 in the light collector 8 is changed from the direction of the first scheduled cutting surface 42 to the direction of the second scheduled cutting surface 43.

  In step S <b> 6, the scribing apparatus 1 moves the light converging unit 8 to a place where the laser beam 37 can be irradiated to the place 43 a that becomes the end of the substrate 41 on the second scheduled cutting surface 43.

  FIG. 7B and FIG. 7C are diagrams corresponding to step S7. As shown in FIGS. 7B and 7C, the laser beam 37 is condensed in the X direction and irradiated from the condensing unit 8 to the inside of the substrate 41. A reforming portion 45 is formed at the condensing place 37 a where the laser beam 37 is condensed and irradiated, and a crack portion 46 is formed at the center of the reforming portion 45.

  Compared with the first direction 38, the laser beam 37 is condensed and irradiated on the substrate 41 in the second direction 39 so that the numerical aperture of the laser light 37 is increased. That is, the condensing lens 8a does not condense the laser light 37 in the first direction 38, but condenses it in the second direction 39, so that the reforming unit 45 is long in the first direction 38 and the second direction. 39 is formed in a short shape.

  Since the first direction 38 is arranged in the direction of the second scheduled cutting surface 43, the reforming portion 45 is formed in a shape that is long along the second scheduled cutting surface 43 and short in the X direction.

  In step S7, after the laser beam 37 is irradiated, the process proceeds to step S8. In step S <b> 8, the main computer 24 determines whether the reforming portion 45 has been formed on all of the second scheduled cutting surfaces 43. In the storage unit of the main computer 24, data of a place where the reforming unit 45 is to be formed and a place where the reforming unit 45 has already been formed are stored on the second scheduled cutting surface 43. In step S <b> 7, each time the reforming unit 45 is formed, the main computer 24 stores the data of the place formed in the storage unit. It is determined whether or not there is a place where the reforming part 45 is to be formed and the reforming part 45 is not formed. When there is a place where the reforming unit 45 is not formed, the process moves to that place in step S9.

  FIG. 8A is a diagram corresponding to step S9. As shown in FIG. 8A, the substrate 41 and the light collecting unit 8 are relatively moved in the first direction 38. For example, in this embodiment, the moving distance is a distance slightly shorter than the width of the reforming unit 45 in the first direction 38.

  FIG. 8B and FIG. 8C are diagrams corresponding to step S7. As shown in FIG. 8B, the laser beam 37 is condensed and irradiated in the X direction from the condensing unit 8 to the inside of the substrate 41. A reforming portion 45 is formed at the condensing place 37 a where the laser beam 37 is condensed and irradiated, and a crack portion 46 is formed at the center of the reforming portion 45. As a result, the reforming portions 45 are formed in an array.

  As shown in FIG. 8C, the reforming portions 45 are arranged and formed to form the first-stage reforming portion 45c. Subsequently, the reforming portions 45 are arranged and formed at positions adjacent to the first-stage reforming portion 45c in the Z direction to form the second-stage reforming portion 45d. In this manner, the modified portions 45 are formed in multiple stages, and the second scribe surface 48 on which the modified portions 45 are formed is formed on the entire second cut planned surface 43.

  FIG. 9A and FIG. 9B are diagrams corresponding to step S10. As shown in FIG. 9A, the substrate 41 is placed on a base 49 made of at least an elastic material. A place facing the first scribe surface 47 formed on the first cut planned surface 42 is pressed using the pressing member 50. The substrate 41 sinks into the base 49 and a tension acts on the crack portion 46. The substrate 41 breaks and breaks starting from the crack portion 46 close to the surface in contact with the base 49.

  Similarly, as shown in FIG. 9B, a place facing the second scribe surface 48 formed on the second scheduled cutting surface 43 is pressed using the pressing member 50. The substrate 41 sinks into the base 49 and a tension acts on the crack portion 46. The substrate 41 breaks and breaks starting from the crack portion 46 close to the surface in contact with the base 49.

  As a result, the substrate 41 shown in FIG. 4A is divided by the first scheduled cutting surface 42 and the second scheduled cutting surface 43 and divided into four.

As described above, this embodiment has the following effects.
(1) According to the present embodiment, the scribing apparatus 1 includes the laser light source 2 and the light collecting unit 8. The laser light source 2 emits laser light 37. The condensing unit 8 condenses and irradiates the laser light 37 inside the substrate 41. The condensing unit 8 has a larger numerical aperture of the laser light 37 in the second direction 39 orthogonal to the optical axis 7 and the first direction 38 than in the first direction 38 orthogonal to the optical axis 7 of the laser light 37. In this way, the light is condensed and applied to the substrate 41.

  A reforming portion 45 is formed at a condensing place 37 a where the laser beam 37 is condensed on the substrate 41. Since the numerical aperture of the laser beam 37 is larger in the second direction 39 than in the first direction 38, the formed modified portion 45 has a shape that is longer in the first direction 38 than in the second direction 39. Become. In other words, the modified portion 45 that is long in the first direction 38 can be formed. Therefore, when the modified portions 45 are arranged side by side on the substrate 41 having a predetermined length, the number of irradiations is smaller than when the modified portions 45 having the same length are formed in the first direction 38 and the second direction 39. Thus, the reforming portions 45 can be arranged. As a result, it is possible to scribe with high productivity.

  (2) According to the present embodiment, the scribe device 1 includes the condenser lens 8a. The condensing lens 8 a is an aspheric lens, and has a focal length in the second direction 39 that is shorter than a focal length in the first direction 38. Therefore, the numerical aperture of the laser light 37 that passes through the condenser lens 8 a is larger in the second direction 39 than in the first direction 38. As a result, the long modified portion 45 in the first direction 38 can be formed on the substrate 41 that condenses and irradiates the laser light 37 using the condensing lens 8a.

  (3) According to the present embodiment, the scribe device 1 includes the condensing lens 8a, and the condensing lens 8a is a columnar lens. In the columnar lens, one direction of the cross section is formed by a curve, and another direction is formed by a straight line. When forming all directions in a curved line with respect to the optical axis 7 of the condensing lens 8a, it is necessary to polish the all directions to form a curve, and it takes effort to form the lens. On the other hand, when one direction of the lens is a straight line, it can be said that the lens is easy to form because it can be polished in one direction to form a curve. Therefore, a scribing apparatus including the condensing lens 8a that can be formed with high productivity can be obtained.

  (4) According to the present embodiment, the scribing apparatus 1 includes the light collecting unit 8, and the light collecting unit 8 rotates in the first direction by the condensing lens 8 a rotating about the optical axis 7. 38 and the second direction 39 are changed. A long modified portion 45 in the first direction 38 can be formed on the substrate 41 that condenses and irradiates the laser light 37 using the condensing portion 8. Therefore, by changing the first direction 38 and the second direction 39, the first direction 38 in which the reforming portion 45 is formed long can be set to a desired direction. As a result, the modified portion 45 that is long in a desired direction can be formed.

  (5) According to the present embodiment, the substrate 41 is irradiated with the laser beam 37 from the light converging unit 8 to form the modified unit 45, the irradiation process of Step S2 and Step S7, and the movement of Step S4 and Step S9. Process. In the irradiating step, the substrate 41 is condensed and irradiated in the second direction 39 so that the numerical aperture of the laser light 37 is larger than the first direction 38 orthogonal to the optical axis 7 of the laser light 37. In the moving process, the substrate 41 and the light collector 8 are relatively moved in the first direction 38. The irradiation process and the movement process are repeated, and the modified portions 45 are arranged and scribed in the first direction 38. Subsequently, in the dividing step, the substrate is pressed and divided.

  In the irradiation process, since the numerical aperture of the laser beam 37 to be irradiated is larger in the second direction 39 than in the first direction 38, the modified portion 45 to be formed is in the first direction compared with the second direction 39. 38 becomes a long shape. In other words, the modified portion 45 that is long in the first direction 38 can be formed. In the moving step, the substrate 41 and the light collecting unit 8 are relatively moved in the first direction 38. By repeating the irradiation process and the movement process, the modified portions 45 that are long in the first direction 38 can be formed in an array in the first direction 38. Therefore, when the modified portions 45 are arranged side by side on the substrate 41 having a predetermined length, the number of irradiations is smaller than when the modified portions 45 having the same length are formed in the first direction 38 and the second direction 39. Thus, the reforming portions 45 can be arranged. As a result, it is possible to scribe with high productivity.

(Second Embodiment)
Next, an embodiment of a method for manufacturing a liquid crystal display device embodying the present invention will be described with reference to FIGS.
In the present embodiment, an example in the case of manufacturing a liquid crystal display device using a method for dividing the substrate of the present invention will be described. Here, before describing the characteristic manufacturing method of the present invention, the liquid crystal display device will be sequentially described.

(Liquid crystal display device)
First, a liquid crystal display device will be described. FIG. 10A is a schematic plan view of the liquid crystal display device, and FIG. 10B is a schematic cross-sectional view taken along the line DD ′ of the liquid crystal display device of FIG.

  10A and 10B, a liquid crystal display device 55 as an electro-optical device according to this embodiment includes a TFT array substrate 56 as a pair of second substrates and a counter substrate 57 as a first substrate. Are bonded together by a sealing material which is a thermosetting sealing material. A liquid crystal layer including at least a liquid crystal 59 as an optical element enclosed in a partitioned region is provided by a seal 58 in which the sealing material is solidified. The seal 58 is formed in a frame shape closed in a region within the substrate surface.

  A peripheral parting 60 for concealing the wiring with a light-shielding material is formed on the surface of the counter substrate 57 on the liquid crystal 59 side inside the seal 58. A data line driving circuit 61 and an electrode terminal 62 are formed along a side 56a (lower side in FIG. 10A) of the TFT array substrate 56 at a location outside the seal 58, and adjacent to the side 56a. The scanning line driving circuit 63 is formed along the side 56b and the side 56c (left and right sides in FIG. 10A). The data line driving circuit 61, the electrode terminal 62, and the scanning line driving circuit 63 are electrically connected by a wiring 64a that is a light transmissive conductive film. On the remaining side 56d (the upper side in FIG. 10A) of the TFT array substrate 56, a wiring 64b, which is a light transmissive conductive film for connecting the two scanning line driving circuits 63, is provided. Yes. In addition, inter-substrate conductive members 65 for providing electrical continuity between the TFT array substrate 56 and the counter substrate 57 are disposed at the four corners of the counter substrate 57.

  The liquid crystal display device 55 is configured for color display. On the counter substrate 57, red (R), green (G), and blue (B) color filters 66R, 66G, and 66B are formed together with a protective film. Yes. A light shielding film 67 is formed between the filter elements of the color filters 66R, 66G, and 66B, and the light shielding film 67 blocks light that does not pass through the color filters 66R, 66G, and 66B. Further, a counter electrode 68 and an alignment film 69 are disposed on the TFT array substrate 56 side of the protective film of the color filters 66R, 66G, and 66B.

  The liquid crystal has the property that the tilt angle of the liquid crystal molecules changes when a voltage is applied to the electrodes sandwiching the liquid crystal, and the tilt angle of the liquid crystal is controlled by controlling the voltage applied to the liquid crystal by the switching operation of the TFT. Then, an operation of transmitting or blocking light is performed for each pixel. Thereby, the transmitted light passes through a color filter having three color filters of red (R), green (G), and blue (B) that are installed relative to each pixel. The color of each corresponding color filter is transmitted as colored light. In addition, since light does not naturally enter the color filter corresponding to the pixel where the light is blocked by the liquid crystal, the color filter is black. In this way, by operating the liquid crystal as a shutter by the switching operation of the TFT, the transmission of light is controlled for each pixel, and the color image can be displayed by blinking the pixel.

  A plurality of pixels are arranged in a matrix of m rows and n columns in the region for displaying an image of the liquid crystal display device 55 having such a structure, and a pixel signal is switched to each of these pixels. A TFT (Thin Film Transistor) which is a switching element is formed. A data line (source wiring) for supplying a pixel signal is electrically connected to the source electrode of the TFT, a scanning line (gate wiring) for supplying a scanning signal is electrically connected to the gate electrode of the TFT, and a drain electrode of the TFT The pixel electrode 70 is electrically connected to the first electrode. The pixel electrode 70 is formed at a location facing the filter elements of the color filters 66R, 66G, and 66B. A scanning signal of a pulse signal is supplied from the scanning line to the gate electrode of the TFT to which the scanning line is connected at a predetermined timing.

  The pixel electrode 70 is electrically connected to the drain electrode of the TFT. By turning the TFT on for a certain period, the pixel signal supplied from the data line is applied to the pixel electrode 70 of each pixel at a predetermined timing. Supplied. The voltage level of the pixel signal of the predetermined level supplied to the pixel electrode 70 in this way is held between the counter electrode 68 of the counter substrate 57 shown in FIG. 10B and according to the voltage level of the pixel signal. The light transmission amount of the liquid crystal 59 changes. The liquid crystal display device 55 includes a color filter, and the light transmitted through the color filters 66R, 66G, and 66B is controlled by an image signal applied to an electrode that sandwiches at least a liquid crystal layer made of the liquid crystal 59, whereby the liquid crystal display device 55 is controlled. Can display color images.

  An alignment film 71 is disposed on the counter electrode 57 side of the pixel electrode 70. The alignment film 69 and the alignment film 71 have groove-like irregularities formed on the surfaces thereof, and the liquid crystal 59 filled between the alignment film 69 and the alignment film 71 is arranged along the groove-like irregularities. Formed.

  In the TFT array substrate 56 and the counter substrate 57, polarizing sheets 72 and 73 are arranged on the surface opposite to the liquid crystal 59, and light transmission that transmits through the liquid crystal display device 55 by the action of the polarizing sheets 72 and 73 and the liquid crystal 59. The amount is changing.

(Manufacturing method of liquid crystal display device)
Next, a method for dividing the substrate in the above-described liquid crystal display device 55 will be described with reference to FIGS. FIG. 11 is a flowchart of a method for manufacturing a liquid crystal display device, and FIG. 12 is a schematic view showing a mother substrate on which a liquid crystal display panel is partitioned. 13 and 14 are diagrams for explaining a method of manufacturing a liquid crystal display device.

  In the flowchart of FIG. 11, step S <b> 11 corresponds to the first scribing process of the counter mother substrate, and is a process of scribing in one direction of the counter mother substrate. Next, the process proceeds to step S12. Step S12 corresponds to the second scribing process of the counter mother substrate, and is a process of scribing in the direction orthogonal to the direction scribed in step S11 on the counter mother substrate. Step S11 and step S12 are collectively referred to as step S21. Step S21 corresponds to a first scribe process. Next, the process proceeds to step S13.

  Step S13 corresponds to the first scribing process of the TFT array mother substrate, and is a process of scribing in one direction of the TFT array mother substrate. Next, the process proceeds to step S14. Step S14 corresponds to the second scribing process of the TFT array mother substrate, and is a process of scribing in the direction orthogonal to the direction scribed in step S13 on the TFT array mother substrate. Step S13 and step S14 are combined into step S22. Step S22 corresponds to a second scribe process. Next, the process proceeds to step S15.

  Step S15 corresponds to the first dividing step of the TFT array mother substrate, and is a step of dividing one direction of the TFT array mother substrate. Next, the process proceeds to step S16. Step S16 corresponds to a second dividing step of the TFT array mother substrate, and is a step of dividing the direction perpendicular to the direction divided in step S15 in the TFT array mother substrate. Next, the process proceeds to step S17. Step S <b> 17 corresponds to a first dividing step of the counter mother substrate, and is a step of dividing one direction of the counter mother substrate. Next, the process proceeds to step S18. Step S18 corresponds to a second dividing step of the counter mother substrate, and is a step of cutting the direction orthogonal to the direction divided in step S17 in the counter mother substrate. Step S15 to step S18 are combined to form step S23. Step S23 corresponds to a dividing step. Through the above steps, the liquid crystal display device 55 is formed.

  Next, the manufacturing method will be described in detail with reference to FIGS. 12 to 14 in association with the steps shown in FIG. FIG. 12A is a schematic diagram showing a mother substrate in which a liquid crystal display device is partitioned. FIG. 12B is a schematic cross-sectional view taken along line E-E ′ of FIG.

  As shown in FIG. 12A and FIG. 12B, a counter mother substrate 80 as a first mother substrate and a TFT array mother substrate 76 as a second mother substrate are bonded together by a sealing material 79, and a mother substrate 82 is obtained. Is formed. A method for manufacturing the counter mother substrate 80 and the TFT array mother substrate 76 and a method for assembling the counter mother substrate 80 and the TFT array mother substrate 76 are well known, and a description thereof will be omitted. The substrate 77 constituting the TFT array mother substrate 76 and the substrate 81 constituting the counter mother substrate 80 are made of quartz glass.

In order to form the liquid crystal display device 55 shown in FIG. 10, the surface on which the counter mother substrate 80 is to be divided is defined as an H counter cutting surface 83 and a V counter cutting surface 84, and the surface on which the TFT array mother substrate 76 is to be divided is formed. They are represented as an H element cut surface 85 and a V element cut surface 86.
The H-opposed cut surface 83 is a cut surface of the opposed mother substrate 80 indicated by a one-dot chain line, and is a cut surface extending in the X-axis direction of FIG. Reference numerals 83a, 83b, 83c, 83d, and 83e shown in FIG.

  The V-opposing cut surface 84 is a cut surface of the opposed mother substrate 80 indicated by a one-dot chain line, and is a cut surface extending in the Y-axis direction of FIG. 84a, 84b, and 84c shown in FIG. 12A are V opposing cut surfaces 84, respectively.

  The H element cut surface 85 is a cut surface of the TFT array mother substrate 76 indicated by a one-dot chain line, and is a cut surface extending in the X-axis direction of FIG. 85a, 85b, and 85c shown in FIG. 12A are H element cut surfaces 85, respectively.

  The V element cut surface 86 is a cut surface of the TFT array mother substrate 76 indicated by a one-dot chain line, and is a cut surface extending in the Y-axis direction of FIG. The V element cutting surface 86 is located at a location facing the V facing cutting surface 84, and 86a, 86b, 86c shown in FIG. 12A are V element cutting surfaces 86, respectively.

  FIG. 13A to FIG. 13B are diagrams corresponding to step S11. As shown in FIG. 13A, in step S11, the irradiation process of irradiating the laser beam 37 along the V facing cut surface 84 of the substrate 81 and the moving process of moving to the next irradiation place are repeated. Do a scribe.

  First, the mother substrate 82 is placed on the stage 20 of the scribing apparatus 1. Subsequently, in the irradiation step, the laser beam 37 is condensed and irradiated by the condensing lens 8 a of the condensing unit 8 inside the substrate 81 of the counter mother substrate 80.

  The condensing lens 8a is arranged so that the first direction 38 in which the cross section of the condensing lens 8a shown in FIG. Accordingly, the second direction 39 in which the cross-section of the condensing lens 8a is a convex lens is a direction orthogonal to the V-opposing cut surface 84.

  Similarly to FIGS. 5B and 5C, the laser beam 37 is condensed in the X direction and irradiated from the condensing unit 8 to the inside of the substrate 81. A reforming portion 45 that is long in the Y direction is formed at the condensing place 37 a irradiated with the laser beam 37. A crack portion 46 is formed at the center of the reforming portion 45. In the present embodiment, since quartz glass is used for the substrate 81, a cavity is formed in the crack portion 46.

  Subsequently, in the moving step, the condensing unit 8 and the substrate 81 are relatively moved in the first direction 38 so that the condensing lens 8a is positioned at a place opposite to the place where the laser light 37 is next irradiated. To do. Subsequently, in the irradiation step, the laser beam 37 is irradiated and the modified portions 45 are arranged and formed. First, in the substrate 81, the modified portion 45 is arranged near the surface 81 a on the TFT array mother substrate 76 side, and a first-stage modified portion 45 e is formed along the V facing cut surface 84 of the substrate 81. Subsequently, the reforming part 45 is arranged at a location adjacent to the first stage to form a second-stage reforming part 45f. In the third and subsequent stages, the reforming portions 45 are arranged and formed in the same manner.

  As a result, as shown in FIG. 13B, the modified portion 45 is formed in an array on all the V facing cut surfaces 84 of the substrate 81, and the crack portion 46 is formed in the center of the modified portion 45. .

  In step S12, the laser beam 37 is irradiated along the H facing cut surface 83 of the substrate 81 to perform scribing. Subsequently, in step S <b> 13, the mother substrate 82 is reversed, and the laser beam 37 is irradiated along the V element cut surface 86 of the substrate 77 to perform scribing. Subsequently, in step S14, the laser beam 37 is irradiated along the H element cut surface 85 of the substrate 77 to perform scribing. The scribing method is the same as in step S11, and detailed description thereof is omitted.

FIG. 14A to FIG. 14B are diagrams corresponding to step S15. As shown in FIG. 14A, the mother substrate 82 is disposed on a base 49 made of at least an elastic material. The TFT array mother substrate 76 of the mother substrate 82 is disposed so as to be in contact with the base 49, and a place where the opposing mother substrate 80 is opposed to the crack portion 46 formed by being arranged on the H element cutting surface 85 is a pressure member. Press using 50. The TFT array mother substrate 76 sinks into the base 49 and a tension acts on the crack portion 46. The TFT array mother substrate 76 breaks and breaks starting from the crack portion 46 close to the surface in contact with the base 49.
As a result, as shown in FIG. 14B, the TFT array mother substrate 76 is divided at the H element cut surface 85.

  In step S16, the crack portion 46 formed along the V element cut surface 86 of the TFT array mother substrate 76 is divided. Subsequently, in step S <b> 17, the mother substrate 82 is inverted to divide the crack portion 46 formed along the H-opposing cut surface 83 of the opposed mother substrate 80. Subsequently, in step S <b> 17, the crack portion 46 formed along the V-opposing cut surface 84 of the opposed mother substrate 80 is divided. The dividing method is the same as that in step S15, and detailed description thereof is omitted.

  Through the above process, the mother substrate 82 is divided and formed into the shape of the liquid crystal display device 55 shown in FIG. 10A, and the polarizing sheets 72 and 73 shown in FIG. Is completed.

As described above, this embodiment has the following effects.
(1) According to this embodiment, the method of manufacturing an electro-optical device includes a first scribe process, a second scribe process, and a dividing process, and irradiates a laser beam 37 to face the TFT array mother substrate 76. Scribe with the mother board 80.

  The scribing method using the laser beam 37 includes an irradiation process and a movement process. In the irradiation step, the TFT array mother substrate 76 and the opposing mother substrate are condensed so that the numerical aperture of the laser light 37 is larger in the second direction 39 than in the first direction 38 orthogonal to the optical axis of the laser light. And 80. In the moving step, the TFT array mother substrate 76 and the counter mother substrate 80 and the light collecting unit 8 are relatively moved in the first direction 38. By repeating the irradiation process and the moving process, the modified portions 45 are arranged in the first direction 38 and scribed.

  In the irradiation process, since the numerical aperture of the laser beam 37 to be irradiated is larger in the second direction 39 than in the first direction 38, the modified portion 45 to be formed is in the first direction compared with the second direction 39. 38 becomes a long shape. In other words, the modified portion 45 that is long in the first direction 38 can be formed. In the moving process, the TFT array mother substrate 76, the counter mother substrate 80 and the light collecting unit 8 are relatively moved in the first direction 38. By repeating the irradiation process and the movement process, the modified portions 45 that are long in the first direction 38 can be formed in an array in the first direction 38. Therefore, when the modified portions 45 are arranged side by side on the TFT array mother substrate 76 and the opposite mother substrate 80 having a predetermined length, the modified portions 45 having the same length are formed in the first direction 38 and the second direction 39. Compared to the case, the modified portions 45 can be arranged with a smaller number of irradiations. As a result, it is possible to scribe with high productivity.

In addition, this invention is not limited to embodiment mentioned above, A various change and improvement can also be added. A modification will be described below.
(Modification 1)
In the first and second embodiments, the condensing lens 8a employs a columnar lens in which the cross section in the first direction 38 is rectangular and the cross section in the second direction 39 is a convex lens. Not only this but the cross section of the 1st direction may be a convex lens or a concave lens. At this time, the lens may be a lens in which the numerical aperture of the laser beam is increased in the second direction so that the modified portion 45 is formed at a condensing place.

  FIG. 15 shows an example of a condensing lens. In this figure, the X direction indicates the first direction 38, and the Y direction indicates the second direction 39. For example, a condensing lens 90 as an objective lens shown in FIG. 15A is a columnar lens whose cross section in the YZ direction has a bowl shape. The condenser lens 91 as the objective lens shown in FIG. 15B has a concave lens in the XZ direction and a convex lens in the YZ direction. The condenser lens 92 as the objective lens shown in FIG. 15C has a concave lens in the XZ direction and a convex lens in the YZ direction. Further, the surface in the direction opposite to the Z direction is a flat surface.

  The condensing lens 93 as an objective lens shown in FIG. 15D has a convex cross section in the YZ direction, and has a curved columnar cross section in the XZ direction. A condenser lens 94 as an objective lens in FIG. 15E is a modification of the condenser lens 92 in FIG. The cross section in the YZ direction is a convex lens, and the surface in the opposite direction to the Z direction is convex. The condenser lens 95 as the objective lens in FIG. 15F is a convex lens having a divided shape on the XY plane passing through the center of gravity of the elliptic sphere. The condenser lens 96 as the objective lens in FIG. 15G is a rugby ball-shaped lens. In either case, the lens can be employed as a lens having a larger numerical aperture of laser light in the Y direction than in the X direction.

(Modification 2)
In the first embodiment and the second embodiment, the condensing lens 8a is used for the condensing unit 8, but a concave mirror may be used instead of the condensing lens 8a. As shown in FIG. 16, the concave mirror 97 having different curvatures in the first direction 38 and the second direction 39 in the cross-sectional shape of the concave mirror 97 may be used. By irradiating the concave mirror 97 with the laser beam 37 through the mirror 98, the laser beam having a larger numerical aperture in the second direction 39 than in the first direction 38 is condensed and irradiated onto the substrate. The mass part 45 may be formed. The same effects as those of the first embodiment and the second embodiment can be obtained.

(Modification 3)
In the first and second embodiments, the substrate 41, the substrate 77, and the substrate 81 are made of quartz glass, but other glasses may be used. Any brittle material may be used as long as it is light transmissive and can form the liquid crystal display device 55 in the second embodiment. For example, in addition to quartz glass, soda-lime glass, borosilicate glass such as Pyrex (registered trademark), alkali-free glass such as OA-10 (manufactured by Nippon Electric Glass Co., Ltd.), and heat-resistant crystallized glass such as Neoceram (registered trademark) , Optical glass, crystal and the like.

(Modification 4)
In the second embodiment, the substrate dividing method of the present invention is used for the liquid crystal display device 55, but it can also be used for electro-optical devices other than the liquid crystal display device 55. As an electro-optical device provided with a substrate, for example, it can be suitably used as a means for dividing a substrate in a plasma display, an organic EL (ELECTROLUMINESCENCE) display, a vacuum fluorescent display, a field emission display, or the like. In any case, in the step of scribing by irradiating the substrate with the laser beam 37, the laser beam 37 is condensed and modified so that the numerical aperture of the laser beam 37 is larger in the second direction 39 than in the first direction 38. By forming the portion 45, it is possible to scribe with high productivity.

(Modification 5)
In the first embodiment and the second embodiment, the YAG laser is used as the laser light source 2, but a femtosecond laser may be used. Any light source may be used as long as the emitted laser light is condensed inside the object to be processed to form the modified portion 45 by multiphoton absorption. For example, a so-called femtosecond laser that emits laser light using titanium sapphire as a solid light source with a pulse width of femtosecond may be employed. As an example of the light emission conditions and the condensing lens conditions, the pulsed laser light has wavelength dispersion characteristics, the center wavelength is 800 nm, and the half width is about 20 nm. The pulse width is about 300 fs (femtosecond), the pulse period is 1 kHz, and the output is about 700 mW. Even in this case, the condensing lens employs a lens in which the numerical aperture of the laser light 37 is different between the first direction 38 and the second direction 39.

(Modification 6)
In the second embodiment, scribing is performed by irradiating the laser beam 37 on the cross section of the H-facing cutting surface 83, the V-facing cutting surface 84, the H-element cutting surface 85, and the V-element cutting surface 86. Depending on the processing conditions, some of the cut surfaces may be scribed by irradiating the laser beam 37, and the other cut surfaces may be cut using other methods. For example, a glass cutter equipped with a diamond wheel or a carbide wheel may be used for scribing and cutting. As another method, cutting may be performed by using a dicing method in which a blade such as a diamond blade is rotated and cut.

(Modification 7)
In the second embodiment, in the first scribing process of step S21, the laser beam 37 is irradiated along the V facing cutting surface 84 and the H facing cutting surface 83 of the substrate 81 to perform scribing. Subsequently, in the second scribe process in step S22, the laser beam 37 is irradiated along the V element cut surface 86 and the H element cut surface 85 of the substrate 77 to perform scribing. The order of the steps is not limited and may be changed. For example, scribing may be performed in the order of the V-facing cutting surface 84, the V-element cutting surface 86, the H-facing cutting surface 83, and the H-element cutting surface 85. At this time, a first scribe process, a second scribe process, a first scribe process, and a second scribe process are performed. Even in this case, the same effect as in the second embodiment can be obtained.

The schematic schematic diagram which shows the structure of the scribing apparatus according to the first embodiment. The principal part schematic diagram which shows the structure of a condensing part. The flowchart of the dividing method of a board | substrate. The figure explaining the division | segmentation method of a board | substrate. The figure explaining the division | segmentation method of a board | substrate. The figure explaining the division | segmentation method of a board | substrate. The figure explaining the division | segmentation method of a board | substrate. The figure explaining the division | segmentation method of a board | substrate. The figure explaining the division | segmentation method of a board | substrate. The schematic diagram of the liquid crystal display device which concerns on 2nd Embodiment. The flowchart of the manufacturing method of a liquid crystal display device. The schematic diagram which shows the mother board | substrate with which the liquid crystal display panel was dividedly formed. 4A and 4B illustrate a method for manufacturing a liquid crystal display device. 4A and 4B illustrate a method for manufacturing a liquid crystal display device. The principal part schematic diagram which shows the condensing lens which concerns on the modification 1. FIG. The principal part schematic diagram which shows the condensing part which concerns on the modification 2. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Scribe device, 2 ... Laser light source, 7, 7a ... Optical axis, 8a, 90, 91, 92, 93, 94, 95, 96 ... Condensing lens as an objective lens, 8 ... Condensing part, 9 ... Substrate 38 ... first direction, 39 ... second direction, 41 ... substrate, 45e ... first-stage modified portion, 55 ... liquid crystal display device as electro-optical device, 56 ... TFT array as second substrate Reference numeral 57: Counter substrate as a first substrate, 59: Liquid crystal as an optical element, 76: TFT array mother substrate as a second mother substrate, 80 ... Counter mother substrate as a first mother substrate

Claims (6)

A scribing device for scribing a substrate by irradiating a laser beam,
A laser light source for emitting the laser light;
Condensing and irradiating the laser light inside the substrate, forming a reforming portion, and
The condensing unit concentrates so that the numerical aperture of the laser beam is larger in the second direction perpendicular to the optical axis and the first direction than in the first direction orthogonal to the optical axis of the laser beam. A scribing apparatus for irradiating the substrate with light. The scribing device according to claim 1,
The condensing unit includes an objective lens,
The scribing apparatus according to claim 1, wherein the objective lens is an aspherical lens having a focal length in the second direction that is shorter than a focal length in the first direction. The scribing device according to claim 2,
The scribing apparatus, wherein the objective lens is a columnar lens. The scribing device according to any one of claims 1 to 3,
The condensing unit rotates about the optical axis, and the first direction and the second direction change, and the scribing apparatus is characterized in that A substrate dividing method in which a substrate that transmits visible light is irradiated with laser light from a condensing part, a modified part is formed, scribed, and divided.
Compared with the first direction orthogonal to the optical axis of the laser beam, the laser beam is condensed and focused on the substrate in the second direction orthogonal to the optical axis and the first direction so that the numerical aperture of the laser beam is increased. An irradiation process of irradiating;
A moving step of relatively moving the substrate and the light collecting unit in the first direction;
A dividing step of pressing and dividing the substrate,
The substrate cutting method, wherein the irradiation step and the moving step are repeated to scribe and scribe the modified portions in the first direction. A method for manufacturing an electro-optical device, in which an optical element is sandwiched and bonded between a first substrate and a second substrate,
A first scribing step of scribing a first mother substrate in which the first substrate is formed in a plurality of rows and columns;
A second scribing step of scribing a second mother substrate in which the second substrate is formed in a plurality of rows and columns;
A dividing step of dividing the first mother substrate and the second mother substrate;
At least in any one of the first scribe process and the second scribe process,
The first mother substrate or the second mother substrate is irradiated with a laser beam from a condensing part, a modified part is formed, and a scribing step is performed for scribing.
The scribing step has an irradiation step and a moving step,
In the irradiation step, the laser beam is condensed so that the numerical aperture of the laser beam is larger in the second direction orthogonal to the optical axis and the first direction than in the first direction orthogonal to the optical axis of the laser beam. And irradiate the substrate,
In the moving step, the substrate and the light collecting unit are relatively moved in the first direction,
In the scribing step, the irradiation step and the moving step are repeated, and the modification portion is arranged in the first direction for scribing.

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