JP2008155269A - Dividing method for substrate, and method of manufacturing laser scribing apparatus and electro-optical apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate dividing method free from the effect of a binding agent through which a laser beam permeates during laser scribing, and a manufacturing method of a laser scribing apparatus and an electro-optical apparatus. <P>SOLUTION: The dividing method of a substrate is used for dividing a first substrate 9a when the first substrate 9a and a second substrate 9b are jointed with a binding agent 9c. In an optical attenuation measurement step, the optical attenuation amount is measured which is the optical attenuation amount of ultraviolet beam 15 during permeation of the ultraviolet beam 15 through the binding agent 9c when the ultraviolet beam 15 is irradiated to the binding agent 9c. Then, in an irradiation step, laser beam 7 is irradiated to the first substrate 9a from the second substrate 9b side to generate a reformed region 60 inside the first substrate 9a. Further, in the dividing step, pressure is applied on the reformed region 60 to divide the first substrate 9a. In the irradiation step, when the laser beam 7 permeates through the binding agent 9c, the laser beam 7 of a large intensity is irradiated to the spot causing the large optical attenuation in comparison to the spot causing the small optical attenuation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for dividing a substrate using a laser beam, a laser scribing device, and a method for manufacturing an electro-optical device, and more particularly to a method for dividing a substrate bonded using an adhesive.

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

  When a substrate on which two substrates are bonded via an adhesive is scribed by irradiating the laser beam, the laser beam may be irradiated through the adhesive. When the laser beam passes through the adhesive, the optical energy of the laser beam may be absorbed by the adhesive. At this time, the light energy of the laser beam that has passed through the adhesive is attenuated. Since the thickness of the adhesive changes depending on the warpage or distortion of the two substrates, the thickness of the adhesive also changes when the location of the substrate changes. In places where the thickness of the adhesive is thick, the amount of laser light absorbed is increased, and the modified portion may not be formed or the modified portion may be formed small.

  When the modified part is not formed or when the modified part is small, even if stress is applied to the substrate, it becomes difficult to break, and is not divided along the modified part, resulting in a large uneven section.

  The present invention has been made paying attention to such a conventional problem, and when laser scribing, a substrate cutting method, a laser scribing device, and an electro-optical device that are hardly affected by an adhesive through which laser light passes are disclosed. An object is to provide a manufacturing method.

  In order to solve the above problems, a method for dividing a substrate according to the present invention is a substrate dividing method for dividing a first substrate in which a first substrate and a second substrate are bonded via an adhesive, Light attenuation corresponding to the amount of light after the amount of measurement light is attenuated when the measurement light irradiates the adhesive located between the first substrate and the second substrate and passes through the adhesive. Measuring the amount of light, measuring the amount of light attenuation, irradiating the first substrate with laser light from the second substrate side, forming the modified portion inside the first substrate, and pressing the modified portion In the irradiation process, when the laser beam passes through the adhesive, the light intensity is larger in a place where the light attenuation is larger than in the place where the light attenuation is small. It is characterized by irradiating with laser light.

  According to this substrate dividing method, the amount of light attenuation by the adhesive is measured, and a laser beam having a light amount corresponding to the amount of light attenuation is irradiated. When the first substrate and the second substrate are bonded via an adhesive, a modified portion is formed on the first substrate by irradiating laser light through the adhesive from the second substrate side. There are things to do.

  At this time, among the adhesives, there is an adhesive having high laser light absorption. Since the adhesive absorbs the laser light, the laser light passing through the adhesive is attenuated. In the place where the adhesive is thick, the laser beam is greatly attenuated compared to the place where the adhesive is thin.

  When the first substrate and the second substrate are bonded, the thickness of the adhesive may vary depending on the location due to warpage and distortion between the first substrate and the second substrate. Therefore, when the laser beam passes through the adhesive, the amount of light attenuation by which the laser beam attenuates may vary depending on the location.

  In the present invention, after measuring the amount of light attenuation at a plurality of locations, a large amount of laser light is irradiated at a location where the amount of light attenuation is large. Therefore, even if the laser beam passes through the adhesive and the amount of light is attenuated, the amount of light necessary for forming the modified portion can be condensed on the first substrate. As a result, the modified portion can be formed with high quality, so that the substrate can be divided with high quality.

  In the substrate cutting method according to the present invention, the light attenuation measurement step is characterized in that the amount of light attenuation is measured by irradiating the adhesive with laser light having substantially the same wavelength as the laser light irradiated in the irradiation step.

  According to this substrate cutting method, the amount of light attenuation is measured using laser light having substantially the same wavelength as the laser light irradiated in the irradiation step. When the adhesive is irradiated with light, the absorbance indicating the rate at which the adhesive absorbs light has different properties depending on the wavelength of the irradiated light. In the present invention, since the wavelength of the laser beam irradiated in the irradiation step and the wavelength when measuring the optical attenuation amount are substantially the same wavelength, the optical attenuation amount at substantially the same wavelength is measured. Therefore, it is possible to accurately measure the amount of light attenuation when the laser light irradiated in the irradiation process passes through the adhesive.

  In the substrate cutting method according to the present invention, the light attenuation measurement step irradiates the adhesive with measurement light having a wavelength different from that of the laser light irradiated in the irradiation step, and measures the light attenuation by the adhesive. Light that calculates optical attenuation in laser light by using correlation data between optical attenuation at the wavelength of measurement light and optical attenuation at the wavelength of laser light irradiated in the irradiation process. An attenuation amount calculating step.

  According to the method for dividing the substrate, after measuring the light attenuation amount in the measurement light having a wavelength different from that of the laser light irradiated in the irradiation step, the light attenuation in the laser light irradiated in the irradiation step is performed using the measured light attenuation amount. The quantity is calculated and estimated. There are several methods for emitting laser light. The laser light used for scribing is emitted using a device capable of irradiating large energy. When measuring the amount of light attenuation, it is possible to measure with less energy than the energy that can be scribed.

  When a device that emits light of low energy emits light, light can be emitted using a principle different from the principle of emitting laser light emitted in the irradiation process. At this time, since the principle of light emission is different, the wavelength of emitted light is often different. In the present invention, after measuring the light attenuation amount in the measurement light having a wavelength different from that of the laser light irradiated in the irradiation step, the light attenuation amount in the laser light irradiated in the irradiation step is calculated using the measured light attenuation amount. Estimated. Therefore, it is possible to estimate the amount of light attenuation using a light emitting device that emits light of weak energy different from the laser light used for scribing. As a result, energy consumption can be reduced, so that a resource saving method can be achieved.

  The substrate cutting method of the present invention has a storage step of storing the light attenuation amount and the measurement location where the light attenuation amount is measured after the light attenuation amount measurement step, and the irradiation step stores the light attenuation amount in the storage step. After calculating the light attenuation amount at the irradiation location using the measurement location and the light attenuation amount, the light attenuation amount is used to calculate and irradiate the amount of laser light that can form the modified portion. It is characterized by.

  According to this substrate dividing method, after measuring the light attenuation, the measured location and the light attenuation are stored. Thereafter, using the measured location and the light attenuation, the amount of light necessary to form the modified portion at the location to be irradiated is calculated and irradiated. Therefore, it is not necessary to perform an irradiation process after the light attenuation measurement process. After performing the light attenuation measurement process and the storage process, another process can be performed, and then the irradiation process can be performed. As a result, it is possible to make the method easy to design the manufacturing process.

  The substrate cutting method of the present invention is characterized in that the light attenuation measurement step and the irradiation step are performed in parallel.

  According to this substrate cutting method, the light attenuation measurement step and the irradiation step are performed in parallel. When the light attenuation measurement process and the irradiation process are performed separately, it takes time to combine the time required for measuring the light attenuation and the time required for irradiation. In the present invention, by performing the light attenuation measurement step and the irradiation step in parallel, it is possible to process in a shorter time than when performing separately. As a result, the method can be manufactured with high productivity.

  In order to solve the above-described problems, a laser scribing apparatus according to the present invention is a laser scribing apparatus that performs scribing by irradiating laser light onto a first substrate in which a first substrate and a second substrate are bonded via an adhesive. Then, when the measurement light is irradiated to the adhesive located between the first substrate and the second substrate, and the measurement light passes through the adhesive, the amount of the measurement light is reduced to the light amount. A light attenuation measurement unit that measures the corresponding light attenuation, and a light amount control unit that controls the amount of laser light applied to the first substrate, and the amount of light attenuation when the laser light passes through the adhesive; Compared with a small area, a large amount of laser light is irradiated in a place where the amount of light attenuation is large.

  According to this laser scribing device, the light attenuation measurement unit measures the light attenuation after being attenuated by the adhesive. The light amount control unit irradiates the laser light while controlling the amount of laser light corresponding to the light attenuation amount. When the first substrate and the second substrate are bonded via an adhesive, a modified portion is formed on the first substrate by irradiating laser light through the adhesive from the second substrate side. There are things to do.

  At this time, among the adhesives, there is an adhesive having high laser light absorption. In the present invention, after measuring the amount of light attenuation at a plurality of locations, a large amount of laser light is irradiated at a location where the amount of light attenuation is large. Therefore, even if the amount of light is attenuated by the laser light passing through the adhesive, the amount of light necessary for forming the modified portion can be condensed on the first substrate. As a result, the modified portion can be formed with high quality, so that the substrate can be divided with high quality.

  In the laser scribing apparatus of the present invention, the light attenuation measurement unit irradiates the adhesive with laser light and measures the light attenuation.

  According to this laser scribing apparatus, the amount of light attenuation is measured using a laser beam having substantially the same wavelength as the laser beam used for laser scribing. When the adhesive is irradiated with light, the absorbance indicating the rate at which the adhesive absorbs light has different properties depending on the wavelength of the irradiated light. In the present invention, when scribing, the wavelength of the laser beam to be irradiated and the wavelength when measuring the amount of light attenuation are substantially the same wavelength, and thus the amount of light attenuation at substantially the same wavelength is measured. Therefore, it is possible to accurately measure the amount of light attenuation when the laser light irradiated in the irradiation process passes through the adhesive.

  In the laser scribing apparatus of the present invention, the light attenuation measurement unit irradiates the adhesive with measurement light having a wavelength different from that of the laser light, and measures the light attenuation by the adhesive. Using the correlation data between the light attenuation at the wavelength of light and the light attenuation attenuated when the laser light irradiated in the irradiation process irradiates the same adhesive thickness, the light attenuation in the laser light is calculated. And an optical attenuation amount calculating unit.

  According to this laser scribing apparatus, after measuring the amount of light attenuation when the adhesive is irradiated with measurement light having a wavelength different from that of the laser light irradiated when scribing, the adhesive having the same thickness is scribed. Correlation data is prepared by measuring the amount of light attenuation when the laser light irradiated when the light passes through. Then, the light attenuation amount in the laser light irradiated when scribing is calculated and estimated using the light attenuation amount when the measurement light is irradiated. There are several methods for emitting laser light. The laser light used for scribing is emitted using a device capable of irradiating large energy. When measuring the amount of light attenuation, it is possible to measure with less energy than the energy that can be scribed.

  When a device that emits light of low energy emits light, light may be emitted using a principle different from the principle of emitting laser light emitted in the irradiation process. At this time, since the principle of light emission is different, the wavelength of emitted light is often different. In the present invention, after measuring the optical attenuation amount in the measurement light having a wavelength different from that of the laser beam irradiated when scribing, the optical attenuation amount in the laser beam irradiated when scribing is measured using the measured optical attenuation amount. Is calculated and estimated. Therefore, it is possible to estimate the amount of light attenuation using a light emitting device that emits light of weak energy different from the laser light used for scribing. As a result, energy consumption can be reduced, so that a resource saving method can be achieved.

  In order to solve the above-described problem, a method for manufacturing an electro-optical device according to the present invention is a method for manufacturing an electro-optical device having a first substrate in which a first substrate and a second substrate are bonded via an adhesive. And when dividing | segmenting a 1st board | substrate, it divides | segments using the division | segmentation method of the board | substrate described above, It is characterized by the above-mentioned.

  According to the method for manufacturing the electro-optical device, the substrate can be divided with high quality by forming the modified portion with high quality even when scribing by irradiating laser light through the adhesive. As a result, an electro-optical device including a substrate divided with high quality can be obtained.

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 device for detecting the thickness of an adhesive is used to scribe and divide by a laser scribing method. Here, the scribing apparatus will be described with reference to FIG. 1 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.
As shown in FIG. 1, the laser scribing apparatus 1 includes a laser light source 2 as a laser light source unit that emits a laser beam, an optical path unit 3 that irradiates a workpiece with the emitted laser beam, and an optical path unit 3. The table unit 4 that relatively moves the workpiece and the control device 5 that controls 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 7 emitted from the laser light source 2. The half mirror 6 reflects the laser beam 7 emitted from the laser light source 2 and changes the traveling direction from the optical axis 7a to the optical axis 7b. A condensing unit 8 is disposed on the optical axis 7b through which the laser light 7 reflected by the half mirror 6 passes. The condensing part 8 is provided with a condensing lens 8a which is a convex lens in the inside thereof so that the laser beam 7 can be condensed on the condensing place 7c. A substrate 9 is disposed on the table unit 4, and the substrate 9 is irradiated with the laser light 7 that has passed through the condensing unit 8.

  The substrate 9 is formed by bonding a first substrate 9a and a second substrate 9b with an adhesive 9c. The first substrate 9a and the second substrate 9b may be light transmissive plates, and quartz glass is used in the present embodiment. The adhesive 9c only needs to be a light-transmitting adhesive after being solidified, and in this embodiment, a photo-curable epoxy resin is employed.

  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), and moves the condensing unit 8 in the direction in which the optical axis 7b travels (Z direction in the figure), so that the laser light 7 that has passed through the condensing unit 8 is collected. The light condensing place 7c is movable.

  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 in the direction of the optical axis 7b. It moves forward or backward along.

  An imaging device 12 is provided on an extension line of the optical axis 7 b that passes through the light collecting unit 8 and the half mirror 6, on the opposite side of the light collecting unit 8 with respect to the half mirror 6. The imaging device 12 includes, for example, a coaxial incident light source and a CCD (Charge Coupled Device) (not shown). Visible light emitted from the coaxial incident light source passes through the condensing unit 8 and irradiates the substrate 9. The imaging device 12 can image the substrate 9 through the light collecting unit 8 and the half mirror 6.

  A light receiving device 13 is provided on the right side of the lens moving mechanism 11, and the light receiving device 13 is located at a location facing the substrate 9. A light projecting device 14 is disposed on the opposite side of the substrate 9 at a location facing the light receiving device 13. The light projecting device 14 includes an ultraviolet light emitting diode therein, and emits ultraviolet light 15 as measurement light. The wavelength of the light emitted from the ultraviolet light emitting diode is preferably close to the wavelength of the laser beam 7, and for example, a wavelength of 386 nm is adopted. And the ultraviolet light 15 irradiates the board | substrate 9 through the light projection lens 14a with which the light projection apparatus 14 is provided. The ultraviolet light 15 applied to the substrate 9 passes through the substrate 9 and is applied to the light receiving unit 13 a of the light receiving device 13.

  The light receiving device 13 includes a phototransistor, and the phototransistor is irradiated with the ultraviolet light 15 irradiated to the light receiving unit 13a. The phototransistor converts the received ultraviolet light 15 into a current value. The light receiving device 13 outputs a light receiving voltage value obtained by converting a current value converted from the ultraviolet light 15 into a voltage value.

  The table unit 4 includes a base 16. On the side of the optical path portion 3 of the base 16, a rail 17 is provided so as to protrude, and an X-axis slide 18 is provided on the rail 17. The X-axis slide 18 includes a linear motion mechanism (not shown) and can move in the X direction on the rail 17. 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 18 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 19 protrudes from the X-axis slide 18 on the optical path section 3 side, and a Y-axis slide 20 is arranged on the rail 19. The Y-axis slide 20 includes a linear motion mechanism similar to that of the X-axis slide 18 and is movable on the rail 19 in the Y direction.

  A rotary table 21 serving as a direction switching device is disposed on the optical path unit 3 side of the Y-axis slide 20. The turntable 21 has a rotation mechanism (not shown), and when the X-axis slide 18 and the Y-axis slide 20 move by rotating the substrate 9, the direction in which the substrate 9 moves can be changed.

  The rotation mechanism is, for example, a rotation mechanism provided with a step motor having a gear on a drive shaft and a reduction gear meshing with the gear. The drive shaft receives a predetermined pulse signal and performs forward / reverse rotation in predetermined step units. When a drive signal corresponding to a predetermined number of steps is input to the step motor, the step motor rotates normally or reversely, and the rotary table 21 rotates by an amount corresponding to the number of steps. .

  A stage 22 is disposed on the optical path section 3 side of the rotary table 21, and a suction chuck mechanism (not shown) is provided on the upper surface of the stage 22. When the substrate 9 is placed, the substrate 9 is positioned and fixed at a predetermined position on the upper surface of the stage 22 by the chuck mechanism.

  The stage 22 is hollow inside, and the light projecting device 14 is provided inside the stage 22. The light projecting device 14 is supported by a support portion 23 erected on the base 16. The stage 22 has a hole portion 22a formed on the surface on the support portion 23 side, and a portion of the support portion 23 passes through the hole portion 22a and extends into the stage 22. Therefore, the support portion 23 can support the light projecting device 14.

  A hole 22 b is formed in the stage 22 on the optical path portion 3 side. The ultraviolet light 15 irradiated by the light projecting device 14 can pass through the hole 22b and the substrate 9 to irradiate the light receiving device 13.

  The control device 5 includes a main computer 26, an interface 27, and a memory 28. The main computer 26 includes a CPU (Central Processing Unit) (not shown). The CPU controls the operation of the laser scribing apparatus 1 according to the program software 29 stored in the memory 28. As specific function realization units, there are a laser light irradiation calculation unit 30, a light attenuation calculation unit 31, and the like.

  The laser beam irradiation calculation unit 30 has a function of calculating a place where the laser beam 7 is irradiated, a light amount of the laser beam 7, and the like. The light attenuation calculation unit 31 calculates the amount of light that attenuates when the laser light 7 irradiated by the laser light source 2 passes through the substrate 9 based on the amount of light that attenuates when the ultraviolet light 15 passes through the substrate 9. Has functions etc.

  The memory 28 is a concept including a semiconductor memory such as a RAM and a ROM, and an external storage device such as a hard disk and a CD-ROM. Functionally, a storage area is set for storing program software 29 in which an operation control procedure in the laser scribing apparatus 1 is described. Furthermore, a storage area for storing irradiation position data 32 which is coordinate data of a position where the laser beam 7 is irradiated in the substrate 9 is also set. In addition, a storage area for storing the light attenuation amount data 33 used when the light attenuation amount calculating unit 31 calculates the attenuation amount of the light amount is set. In addition, a work area for the main computer 26, a storage area that functions as a temporary file, and other various storage areas are set.

  The interface 27 is connected to an input device 34, a display device 35, a laser light control device 36, a lens control device 37, an image calculation device 38, a light attenuation measurement device 39 as an attenuation light amount measurement unit, a stage control device 40, and the like. Yes.

  The input device 34 is a device for inputting data of various processing conditions used in laser processing, and the display device 35 is a device for displaying various information at the time of laser processing. The main computer 26 irradiates the laser beam 7 in accordance with various processing conditions and program software 29 that are input, and displays the processing status on the display device 35. The operator looks at various information displayed on the display device 35 and confirms the machining status for operation.

  The laser light control device 36 is a device that controls the pulse width of the pulse signal that drives the laser light source 2, the pulse period, the start and stop of output, and the like, and is controlled by the control signal of the main computer 26.

  The lens control device 37 is a device that controls the movement and stop of the lens moving mechanism 11. The lens moving mechanism 11 has a built-in position sensor (not shown) that can detect the moving distance, and the lens control device 37 detects the output of the position sensor to detect the position of the light collecting unit 8 in the direction of the optical axis 7b. Recognize position. The lens control device 37 can transmit a pulse signal to the lens moving mechanism 11 to move the lens moving mechanism 11 to a desired position.

  The image calculation device 38 has a function of calculating image data output from the imaging device 12. When the substrate 9 is placed on the stage 22 and an image captured by the imaging device 12 is observed, the lens moving mechanism 11 is operated to change the distance between the light condensing unit 8 and the substrate 9 to make the image clear. There are times when it is blurred. When the condensing unit 8 is moved to focus on the surface of the substrate 9 on the stage 22 side and when the surface of the substrate 9 on the optical path unit 3 side is in focus, 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 substrate 9 is measured by moving the condensing unit 8 in the direction of the optical axis 7b and detecting the position of the condensing unit 8 at which the image captured by the imaging device 12 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 that is in focus when the imaging device 12 takes an image and the condensing position that is condensed by the condensing unit 8 when the laser beam 7 is irradiated. It is possible to know the offset distance that is the difference between the position and the light collection position. For example, an object obtained by superposing two transparent substrates is placed on the stage 22 as the substrate 9, and the light collecting unit 8 is moved so that the imaging device 12 is focused on the contact portion between the two substrates. Next, the modified portion is formed by irradiating the laser beam 7. An offset distance can be set by measuring the distance between the contact portion of the two substrates and the reforming portion.

  The condensing unit 8 is moved in the optical axis 7b direction (Z direction in the drawing), and the imaging device 12 is focused on the surface of the substrate 9 on the optical path unit 3 side. Using the data of the position where the laser beam 7 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 7 can be condensed to a predetermined depth in the substrate 9.

  The light attenuation measurement device 39 is a device that measures the attenuation of the ultraviolet light 15 passing through the substrate 9. After the light receiving device 13 receives the ultraviolet light 15 emitted from the light projecting device 14, the light receiving device 13 converts the ultraviolet light 15 into a received light voltage value corresponding to the received light amount, and outputs it to the light attenuation measuring device 39. The light attenuation measuring device 39 receives the received light voltage value output from the light receiving device 13. Then, the light attenuation amount measuring device 39 calculates the light attenuation amount after converting the light reception voltage value into light amount data that is a light amount corresponding to the light reception voltage value.

  A method for calculating the light attenuation will be described. First, light amount data when there is no attenuation due to the ultraviolet light 15 passing through the substrate 9 is measured, and this light amount data is used as reference light amount data. Subsequently, the light amount data when the ultraviolet light 15 passes through the substrate 9 is measured, and this light amount data is used as measured light amount data. Then, a value obtained by subtracting 1 from the ratio of the measured light amount data to the reference light amount data is set as the light attenuation amount.

  A part of the ultraviolet light 15 passing through the substrate 9 is absorbed by the adhesive 9c, so that the measured light amount data is a value equal to or smaller than the reference light amount data. Therefore, the light attenuation amount is a value between 0 and 1. As the ultraviolet light 15 is absorbed, the measured light quantity data becomes smaller, so the ratio of the measured light quantity data to the reference light quantity data also becomes smaller. The light attenuation amount becomes larger as the ultraviolet light 15 is absorbed because the ratio of the measured light amount data to the reference light amount data is subtracted from 1. Then, the light attenuation measurement device 39 calculates the light attenuation and outputs it to the main computer 26.

  A part of the ultraviolet light 15 passing through the substrate 9 is absorbed by the adhesive 9c. Therefore, the thicker the adhesive 9c, the more the ultraviolet light 15 attenuates. And the amount of light attenuation becomes large.

  The stage control device 40 acquires and moves the position information of the X-axis slide 18, the Y-axis slide 20, and the rotary table 21. The X-axis slide 18, the Y-axis slide 20, and the rotary table 21 have built-in position sensors (not shown), and the stage control device 40 detects the output of the position sensor, so that the X-axis slide 18, the Y-axis slide 20, and The position of the rotary table 21 is detected. The stage control device 40 acquires position information of the X-axis slide 18, the Y-axis slide 20, and the rotary table 21, compares it with position information instructed from the main computer 26, and corresponds to the distance and angle corresponding to the difference. Then, the X-axis slide 18, the Y-axis slide 20, and the rotary table 21 are driven and moved. The stage controller 40 can drive the X-axis slide 18, the Y-axis slide 20, and the rotary table 21 to move the substrate 9 to a desired position and angle.

  After the image calculation device 38 detects the focal position of the condensing lens 8a, the lens control device 37 moves the condensing unit 8 to control the position of the laser beam 7 in the direction of the optical axis 7b. The stage controller 40 moves the substrate 9 in the X and Y directions, thereby controlling the location where the substrate 9 is irradiated with the laser light 7. The laser light control device 36 controls the laser light source 2 to emit the laser light 7. The emitted laser light 7 passes through the optical axis 7 b and is then condensed by the condensing unit 8 to irradiate the inside of the substrate 9. It is possible to collect and irradiate the laser beam 7 at a desired position by performing the control described above.

  Here, formation of the modified portion by multiphoton absorption will be described. The laser beam 7 collected by the condenser 8 is incident on the substrate 9. Even if the substrate 9 is a material that transmits the laser light 7, the substrate 9 absorbs the photon energy when the energy of the photon is much larger than the absorption band gap of the material. This is called multiphoton absorption, and if the energy is increased by making the pulse width of the laser light 7 extremely short and the multiphoton absorption occurs inside the substrate 9, the energy of the multiphoton absorption is not converted into thermal energy. In addition, 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.

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

(Substrate dividing method)
Next, the substrate cutting method of the present invention will be described with reference to FIGS. FIG. 2 is a flowchart of the substrate dividing method, and FIGS. 3 to 6 are diagrams for explaining the substrate dividing method.

  In the flowchart of FIG. 2, step S <b> 1 corresponds to a moving process, which is a process of moving the substrate installed in the scribe device to move the place where the reformer is to be formed to a place facing the light receiving device. . Next, the process proceeds to step S2. Step S2 corresponds to a measuring light attenuation measurement step, and is a step of measuring the amount of light transmitted by irradiating the substrate with ultraviolet rays. Next, the process proceeds to step S3. Step S3 corresponds to a light attenuation amount calculating step, and is a step of calculating the light attenuation amount when irradiating the laser beam using the light amount to be measured in step S2. Step S2 and step S3 are combined to form the light attenuation measurement step of step S21. Next, the process proceeds to step S4.

  Step S4 corresponds to a storage step, and is a step of storing the light attenuation calculated in step S3. Next, the process proceeds to step S5. Step S5 corresponds to a step of determining whether all planned locations have been measured, and is a step of searching for locations where light attenuation has not been measured yet in locations where light attenuation is to be measured. When there is a place where the light attenuation is not yet measured at the place where the light attenuation is to be measured (NO), the process proceeds to step S1. When there is no place where the reforming part is not formed in the place where the reforming part is to be formed (YES), the process proceeds to step S6.

  Step S <b> 6 corresponds to a moving process, and is a process of moving a place where laser light is to be irradiated to a place facing the light collecting unit 8. 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. Next, the process proceeds to step S8.

  Step S8 corresponds to a step of determining whether or not all the planned areas have been irradiated. The area where the reforming part is to be formed is compared with the area where the reforming part is formed, and the reforming part is to be formed. This is a step of searching for a region that has not yet formed the reforming portion. When there is a region where the reforming portion is not yet formed in the region where the reforming portion is to be formed (NO), the process proceeds to step S6. When there is no region where the reforming portion is not formed in the region where the reforming portion is to be formed (YES), the process proceeds to step S9.

  Step S9 corresponds to a step of determining whether or not irradiation is performed in two orthogonal directions, and a step of determining whether or not the reforming portions are arranged and formed in two directions that are directions in which the substrate is to be divided. It is. When an array is formed only in one direction and then a reforming part is formed in another direction orthogonal to each other (NO), the process proceeds to step S10. When the reforming part is formed in two orthogonal directions (YES), the process proceeds to step S11.

  Step S10 corresponds to a rotation process, and is a process of rotating the substrate by 90 degrees using a rotation table. Next, the process proceeds to step S1. Step S11 corresponds to a dividing step, and is a step of dividing the substrate by pressing a place where the modified portions of the substrate are arranged and formed. The process of dividing the substrate is completed by the above steps.

  Next, the manufacturing method will be described in detail with reference to FIGS. 1 and 3 to 6 in association with the steps shown in FIG. FIG. 3A is a schematic plan view of a substrate to be divided in the present embodiment. As shown in FIG. 3A, the substrate 9 is formed of a rectangular plate. The substrate 9 is made of a material that is transparent to the laser light 7 and, for example, quartz glass is used in the present embodiment.

  In the plane direction of the substrate 9, the longitudinal direction of the substrate 9 is arranged in the X direction, and the direction orthogonal to the X direction is defined as the Y direction. The thickness direction of the substrate 9 is the Z direction. In the substrate 9, 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 43. Similarly, in the substrate 9, 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 44. The first scheduled cutting surface 43 is a surface to be scribed in Steps S1 to S9, and the second scheduled cutting surface 44 is scribed by repeating Step S1 to Step S9 after rotating the substrate 9 in Step S10. Surface.

  FIG. 3B is a diagram corresponding to step S1. As shown in FIG. 3 (b), the direction in which the light collecting unit 8 and the light receiving device 13 are arranged is aligned with the direction of the first scheduled cutting surface 43, and is arranged at a location facing the first scheduled cutting surface 43. . At this time, the direction and the location of the substrate 9 are moved by driving the X-axis slide 18, the Y-axis slide 20, and the rotary table 21. A measurement point 45 that is a place to be measured is set on the first scheduled cutting surface 43. In the present embodiment, nine measurement points 45 are set, and measurement points 45a to 45i in the figure indicate the measurement points 45. Then, the substrate 9 is moved, and the substrate 9 is moved such that the first measurement point 45 a is a place facing the light receiving device 13.

  FIG. 3C is a diagram corresponding to step S2. As shown in FIG. 3C, the ultraviolet light 15 is irradiated from the light projecting device 14 toward the light receiving device 13. The ultraviolet light 15 is attenuated by passing through the substrate 9 and then irradiates the light receiving device 13. The light receiving device 13 outputs a voltage value corresponding to the amount of light received to the light attenuation measuring device 39. The light attenuation measuring device 39 calculates the reference light amount data when not passing through the substrate 9 and the light attenuation amount indicating the ratio of the measured light amount data measured this time, and outputs the light attenuation amount to the main computer 26.

  FIG. 4A is a diagram corresponding to step S3. In FIG. 4A, the horizontal axis indicates the thickness 46 of the adhesive, and the right side is thicker than the left side. The vertical axis indicates the light attenuation amount 47, and the light attenuation amount is larger on the upper side than on the lower side. The ultraviolet light attenuation curve 48 shows the relationship of the light attenuation amount 47 with respect to the adhesive thickness 46 when the ultraviolet light 15 irradiated by the light projecting device 14 passes through the substrate 9. Similarly, the laser light attenuation curve 49 shows the relationship of the light attenuation amount 47 with respect to the adhesive thickness 46 when the ultraviolet light 15 emitted from the laser light source 2 passes through the substrate 9.

  In the ultraviolet light attenuation curve 48 and the laser light attenuation curve 49, the amount of light absorbed increases as the thickness 46 of the adhesive increases, so the light attenuation amount 47 increases. The ultraviolet light attenuation curve 48 and the laser light attenuation curve 49 are curves close to the exponential function curve. In step S2, the thickness 51 of the adhesive at the measurement point 45a is estimated using the calculated light attenuation amount 50 and the ultraviolet light attenuation curve 48. Next, by using the adhesive thickness 51 and the laser light attenuation curve 49 at the measurement point 45a, the light attenuation amount 52 when the laser light 7 passes through the adhesive 9c is estimated.

  In step S4, the optical attenuation amount data 33 including the optical attenuation amount 52 calculated in step S3 and the data related to the location of the measurement point are stored in the memory 28.

  In step S5, it is determined whether or not the measurement of the light attenuation amount at all the measurement points 45a to 45i has been completed. When not completed, Steps S1 to S5 are repeated, and the light attenuation amount data 33 at the measurement points 45a to 45i is stored in the memory 28.

  FIG. 4B shows an example of the light attenuation amount data 33 at the measurement points 45a to 45i. In FIG. 4B, the horizontal axis indicates the position 53 in the X direction. The vertical axis indicates the light attenuation amount 47, and the light attenuation amount is larger on the upper side than on the lower side. The light attenuation amount broken line 54 is a broken line connecting the light attenuation amounts 52 at the measurement points 45a to 45i. In the light attenuation amount broken line 54, the light attenuation amount 47 at the measurement point 45e with the position 53 in the X direction at the center is smaller than the light attenuation amounts 47 at the measurement points 45a and 45i at both ends. This is because the thickness of the adhesive 9c is thicker at both ends than the center due to warpage of the first substrate 9a and the second substrate 9b.

  In step S6, the condensing part 8 is moved to a place opposite to the place where the reforming part is to be formed. And the lens moving mechanism 11 moves the condensing part 8 so that the laser beam 7 may be condensed on the place where the reforming part is to be formed.

Step S7 will be described with reference to FIGS. 4B to 5C. In step S7, the light quantity of the laser beam 7 irradiated by the laser beam irradiation calculating unit 30 is calculated. When the position 55 where the laser beam 7 is to be irradiated is between the measurement point 45a and the measurement point 45b, the distance between the measurement point 45a and the position 55 is L1. The distance between the measurement point 45a and the measurement point 45b is L2. The light attenuation amount 47 at the measurement point 45a is Ga, and the light attenuation amount 47 at the measurement point 45b is Gb. The laser light irradiation calculation unit 30 calculates the light attenuation amount 56 that is the light attenuation amount 47 at the position 55 using the following equation.
Light attenuation 56 = Ga + (Gb−Ga) × L1 / L2

  At this time, the light attenuation 56 at the position 55 is plotted on the light attenuation broken line 54. That is, the light attenuation amount 56 is calculated using the light attenuation amount broken line 54. Using this method, the light attenuation amount 47 at a position between the measurement point 45b and the measurement point 45c as the measurement place can be calculated. Similarly, since the light attenuation amount 47 can be calculated between the adjacent measurement points 45, the light attenuation amount 47 can be calculated between the measurement points 45a to 45i.

  FIG. 4C is a diagram showing the relationship between the light attenuation amount 47 at the position 55 and the light irradiation amount 57 necessary for forming the modified portion with respect to the light attenuation amount 47. The horizontal axis indicates the light attenuation amount 47, and the light attenuation amount 47 is larger on the right side than on the left side. The vertical axis indicates the light irradiation amount 57, and the light irradiation amount 57 is larger on the upper side than on the lower side. A light irradiation amount line 58 indicating the relationship between the light attenuation amount 47 and the light irradiation amount 57 is a straight line and is represented by a linear equation. The laser light irradiation calculation unit 30 calculates the light irradiation amount 59 irradiated at the position 55 using the light attenuation amount 56 and the light irradiation amount line 58.

  As shown in FIG. 5A, the condensing unit 8 condenses the laser light 7 and irradiates the inside of the first substrate 9a. A reforming portion 60 is formed at a condensing place 7 c where the laser beam 7 is collected and irradiated, and a hollow crack portion 61 is formed at the center of the reforming portion 60. And the data of the irradiated place are memorize | stored in the irradiation position data 32 as an irradiated position. Since the light amount of the laser light 7 is the light amount calculated by the laser light irradiation calculation unit 30, even if the laser light 7 attenuates when passing through the adhesive 9c, the modified portion 60 is formed.

  In step S <b> 8, the main computer 26 compares the data of the irradiation scheduled position and the irradiated position stored in the irradiation position data 32, and searches for an unirradiated place. At this time, a search is made from the stages forming the reforming unit 60. Then, by repeating step S6 and step S7, first, the first-stage reforming portions 60a are arranged and formed.

  FIG. 5B is a diagram corresponding to step S <b> 7 when the condensing place 7 c that condenses and irradiates the laser light 7 is moved in the Z direction and the processing is continued. As shown in FIG. 5B, the reforming units 60 are arranged at a location adjacent to the reforming unit 60a formed in the first stage to form the second reforming unit 60b. The third and subsequent stages are formed in the same manner.

  After the modified portions 60 are arranged and formed on all the first scheduled cutting surfaces 43 of the first substrate 9a, the first cutting scheduled surfaces 43 of the adhesive 9c are irradiated with the laser beam 7. The adhesive 9c irradiated with the laser beam 7 changes in quality and becomes brittle. Subsequently, in the second substrate 9b, similarly to the first substrate 9a, the modified portions 60 are arranged along the first scheduled cutting surface 43.

  As a result, as shown in FIG. 5C, the first scribe surface in which the modified portions 60 are arranged and formed along the first cut planned surfaces 43 of the first substrate 9a and the second substrate 9b. 62 is formed.

  In step S <b> 9, it is determined whether the first cut planned surface 43 and the second cut planned surface 44 are irradiated with the laser beam 7, the modified portions 60 are arranged, and formed. Since the modified portions 60 are not arranged and formed on the second scheduled cutting surface 44, the process proceeds to step S10.

  FIG. 5D is a diagram corresponding to step S10. As shown in FIG. 5D, the stage control device 40 drives the rotary table 21 to rotate the substrate 9, whereby the light collecting unit 8 and the light receiving device 13 are arranged in the second direction. The direction of the planned cutting surface 44 is matched. Then, the stage control device 40 drives the X-axis slide 18 and the Y-axis slide 20 to move the substrate 9 so that the second cutting scheduled surface 44 comes to a location facing the light receiving device 13.

  Then, Step S1 to Step S8 are repeated. As a result, as shown in FIG. 5C, the second scribe surface 63 in which the reforming portions 60 are arranged and formed is formed along the second scheduled cutting surface 44. In step S <b> 9, after determining that the modified portions 60 are arranged and formed on the second scheduled cutting surface 44, the process proceeds to step S <b> 11.

  FIG. 6A to FIG. 6C are diagrams corresponding to step S11. As shown in FIG. 6A, the substrate 9 is placed on at least a base 64 made of an elastic material or the like. A place facing the first scribe surface 62 formed on the first scheduled cutting surface 43 is pressed using the pressing member 65. The substrate 9 sinks into the base 64 and a tension acts on the crack portion 61. The substrate 9 breaks and breaks starting from the crack portion 61a close to the surface in contact with the base 64.

  Subsequently, as shown in FIG. 6B, similarly, a place facing the second scribe surface 63 formed on the second scheduled cutting surface 44 is pressed using the pressing member 65. The substrate 9 sinks into the base 64 and a tension acts on the crack portion 61. The substrate 9 breaks and breaks starting from the crack portion 61b close to the surface in contact with the base 64.

  As a result, as shown in FIG. 6C, the substrate 9 is divided by the first scribe surface 62 and the second scribe surface 63 and divided into four.

As described above, this embodiment has the following effects.
(1) According to the present embodiment, the amount of light attenuation by the adhesive 9c is measured, and the laser beam 7 is irradiated with a light amount corresponding to the amount of light attenuation. Since the adhesive 9c absorbs the laser light 7, the laser light 7 passing through the adhesive 9c is attenuated. In the place where the adhesive 9c is thick, the laser light 7 is greatly attenuated compared to the place where the adhesive 9c is thin.

  When bonding the first substrate 9a and the second substrate 9b, the thickness of the adhesive 9c may vary depending on the location due to warpage and distortion between the first substrate 9a and the second substrate 9b. Therefore, when the laser beam 7 passes through the adhesive 9c, the amount of light attenuation that the laser beam 7 attenuates may vary depending on the location.

  In the present embodiment, after measuring the light attenuation at a plurality of measurement points 45, the laser light 7 having a large light amount is irradiated at a place where the light attenuation is large. Therefore, even if the laser light 7 passes through the adhesive 9c and the light amount is attenuated, the light amount necessary for forming the modified portion 60 can be condensed on the first substrate 9a. As a result, since the modified portion 60 can be formed with high quality, the substrate can be divided with high quality.

  (2) According to the present embodiment, the amount of light attenuation is measured using the ultraviolet light 15 having a wavelength different from that of the laser light 7 irradiated in the irradiation step of Step S7. The laser beam 7 used for scribing is emitted using a device capable of irradiating large energy. When measuring the amount of light attenuation, it is possible to measure with less energy than the energy that can be scribed.

  In the present invention, after measuring the light attenuation amount in the ultraviolet light 15 emitted by the ultraviolet light emitting diode, the light attenuation amount in the laser light irradiated in the irradiation process of step S7 is calculated and estimated using the measured light attenuation amount. is doing. Therefore, the light attenuation amount is estimated using the light emitting device 14 that emits light of weak energy different from the laser light 7 used for scribing. As a result, energy consumption can be reduced, so that a resource saving method can be achieved. Furthermore, since measurement is performed using light that emits light stably, measurement can be performed with high quality.

  (3) According to the present embodiment, after measuring the light attenuation, the measured measurement point 45 and the light attenuation are stored. Thereafter, using the measured measurement point 45 and the amount of light attenuation, the amount of light necessary to form the modified portion 60 is calculated and irradiated. Therefore, it is not necessary to perform the irradiation process of step S7 after the light attenuation measurement process of step S21. After performing the light attenuation measurement process in step S21 and the storage process in step S4, another process can be performed, and then the irradiation process can be performed. As a result, the process can be easily designed.

(Second Embodiment)
Next, an embodiment of a substrate cutting method embodying the present invention will be described with reference to FIGS. FIG. 7 is a flowchart of the substrate dividing method, and FIG. 8 is a diagram for explaining the substrate dividing method.
This embodiment is different from the first embodiment in that the optical attenuation measurement and the laser light irradiation are performed in parallel when the first-stage modified portion is formed.

  In the flowchart of FIG. 7, step S31 corresponds to a moving process, and is the same process as step S1 of FIG. Next, the process proceeds to step S32. Step S32 corresponds to a measuring light attenuation measurement step, and is a step of measuring the amount of light after attenuation, as in step S2. The difference from step S2 is that all the places where the laser beam 7 is irradiated However, the measurement is different. Step S33 corresponds to the light attenuation calculation step, and is the same step as step S3 in FIG. Step S32 and step S33 are combined to form the light attenuation measurement step of step S51. Next, the process proceeds to step S34. Step S34 corresponds to a storage process, and is the same process as step S4 in FIG. Next, the process proceeds to step S35. Step S <b> 35 corresponds to a first stage irradiation step, and is a step of irradiating the substrate with laser light to form a first stage modified portion.

  Next, the process proceeds to step S36. Step S36 corresponds to a step of determining whether or not all the planned areas in the first stage have been measured, and is a step of searching for a place where the laser light is to be irradiated and a place where the laser light has not been irradiated yet. is there. When there is a place where the laser beam is not irradiated yet at the place where the laser beam is to be irradiated (when NO), the process proceeds to step S31. When there is no place where laser light is not irradiated at a place where laser light is to be irradiated (when YES), the process proceeds to step S37. Steps S37 to S42 are the same as steps S6 to S11 in FIG.

  FIG. 8 is a diagram corresponding to steps S32 to S35. As shown in FIG. 8, in step S <b> 32, the ultraviolet light 15 is irradiated from the light projecting device 14 to the light receiving device 13. At this time, since the ultraviolet light 15 passes through the substrate 9, the amount of the ultraviolet light 15 is attenuated. The light attenuation measuring device 39 calculates the light attenuation using the voltage data corresponding to the amount of light output from the light receiving device 13 and then outputs the light attenuation to the main computer 26.

  In step S33, similarly to step S3, the light attenuation amount in the laser light 7 is calculated using the light attenuation amount in the ultraviolet light 15. In step S 34, the calculated light attenuation amount in the laser beam 7 is stored in the memory 28 as light attenuation amount data 33. In step S <b> 35, the main computer 26 inputs the light attenuation amount data 33 from the memory 28, and calculates light amount data of the laser light 7 that can form the reforming unit 60. The light amount data is output to the laser light control device 36, and the laser light control device 36 causes the laser light source 2 to emit the laser light 7 having the light amount corresponding to the light amount data. And the condensing part 8 condenses and irradiates the laser beam 7 on the condensing place 7c. The reforming part 60 is formed in the condensing place 7c.

  At this time, steps S32 to S34 and step S35 are performed in parallel. Therefore, the table unit 4 moves the substrate 9 and the light receiving device 13 measures the light amount of the ultraviolet light 15 when the light receiving device 13 is located at a place opposite to the place where the light receiving device 13 measures. Subsequently, the light attenuation measuring device 39 calculates the light attenuation using the ultraviolet light 15 received by the light receiving device 13 and then stores it in the memory 28. In parallel with this step, the main computer 26 performs the input of the light attenuation amount data 33 and the calculation of the light amount of the laser light 7 to be irradiated at the next irradiation place. And when the condensing part 8 is located in the place which opposes the place which is going to irradiate the laser beam 7, the laser beam 7 is irradiated.

  Steps S36 to S42 are the same as those in the first embodiment, and a description thereof will be omitted. And the board | substrate 9 is parted and a process is complete | finished.

As described above, according to this embodiment, in addition to the effects (1) and (2) of the first embodiment, the following effects are obtained.
(1) According to the present embodiment, the light attenuation measurement process in step S51 and the first stage irradiation process in step S35 are performed in parallel. When step S51 and step S35 are performed separately, it takes time that is the sum of the time taken for step S51 and the time taken for step S35. In the present invention, by performing step S51 and step S35 in parallel, processing can be performed in a shorter time compared to the case where the steps are performed separately. As a result, the method can be manufactured with high productivity.

(Third embodiment)
Next, an embodiment of a laser irradiation apparatus embodying the present invention will be described with reference to FIG. FIG. 9 is a schematic diagram showing the configuration of the scribe device. This embodiment is different from the first embodiment in that the light attenuation is measured using laser light instead of the light for measuring the light attenuation.

  That is, in the present embodiment, as shown in FIG. 9, the laser scribing device 67 includes a laser light source 2 that emits laser light, an optical path portion 68 that irradiates a workpiece with the emitted laser light, and an optical path portion 68. The table portion 4 for moving the workpiece relative to the head and the control device 5 for controlling the operation are mainly configured. The laser light source 2 and the table unit 4 are the same as those in the first embodiment, and a description thereof will be omitted.

  The optical path unit 68 includes a half mirror 69. The half mirror 69 is disposed on the optical axis 7 a of the laser light 7 emitted from the laser light source 2. The half mirror 69 reflects a part of the laser light 7 emitted from the laser light source 2, changes the traveling direction from the optical axis 7a to the optical axis 7b, and transmits a part of the laser light 7 to the optical axis 7d. To do. On the optical axis 7b through which the laser beam 7 reflected by the half mirror 69 passes, the shutter 70 and the condensing unit 8 are arranged. The shutter 70 is a device that controls the passage and blocking of the laser light 7. When the shutter 70 is shielded, the laser light 7 is blocked, so that the condensing unit 8 is not irradiated.

  A shutter 71 and a reflecting mirror 72 are arranged on an optical axis 7 d through which the laser beam 7 that has passed through the half mirror 69 passes. The shutter 71 is a device that controls passage and blocking of the laser light 7. The reflecting mirror 72 reflects the laser beam 7 and changes the traveling direction from the optical axis 7d to the optical axis 7e. A reflecting mirror 73 is disposed on the optical axis 7e, and the reflecting mirror 73 reflects the laser light 7 and changes the traveling direction from the optical axis 7e to the optical axis 7f. The optical axis 7 f passes through the inside of the stage 22. A reflecting mirror 74 is disposed on the optical axis 7f, and the reflecting mirror 74 reflects the laser beam 7 and changes the traveling direction from the optical axis 7f to the optical axis 7g. The base 16 includes a support portion 75, and the reflection mirror 73 and the reflection mirror 74 are supported by the support portion 75.

  A light receiving unit 13a of the light receiving device 13 is disposed on the optical axis 7g. The laser light 7 emitted from the laser light source 2 passes through the optical axis 7a, the optical axis 7d, the optical axis 7e, the optical axis 7f, and the optical axis 7g, and irradiates the light receiving unit 13a. A substrate 9 is disposed on the optical axis 7g, and the laser light 7 passing through the optical axis 7g is transmitted through the substrate 9 and the amount of light is attenuated. Therefore, the light receiving device 13 can measure the amount of light that the laser light 7 passes through the substrate 9 and attenuates.

  The laser scribing device 67 includes a shutter control device 76. The shutter control device 76 is a device that controls opening and closing of the shutter 70 and the shutter 71. When the shutter 70 and the shutter 71 are opened, the laser light 7 passes, and when the shutter 70 and the shutter 71 are closed, the laser light 7 is blocked.

  Therefore, when measuring the amount of light attenuation without irradiating the laser beam 7 from the condensing unit 8, the shutter control device 76 controls to close the shutter 70 and open the shutter 71. When the light attenuation is not measured by irradiating the laser beam 7 from the condensing unit 8, the shutter control device 76 controls to open the shutter 70 and close the shutter 71. When irradiating the laser beam 7 from the condensing unit 8 and measuring the light attenuation, the shutter control device 76 controls to open the shutter 70 and to open the shutter 71.

As described above, according to the present embodiment, in addition to the effect (1) of the first embodiment, the following effect is obtained.
(1) According to the present embodiment, when the modified portion 60 is formed, the optical attenuation is measured using the same laser light 7 as the laser light 7 to be irradiated. When the adhesive 9c is irradiated with the laser light 7, the absorbance indicating the ratio of the light absorbed by the adhesive 9c varies depending on the wavelength of the irradiated light. In the present embodiment, when the modified portion 60 is formed, the light attenuation amount at the same wavelength is measured because the wavelength of the laser beam 7 to be irradiated and the wavelength at which the light attenuation amount is measured are the same wavelength. ing. Therefore, when forming the modified portion 60, it is possible to accurately measure the amount of light attenuation when the irradiated laser light 7 passes through the adhesive 9c.

(Fourth 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 this embodiment, an example in the case of manufacturing a liquid crystal display device using the substrate cutting method according to the present invention will be described. Here, before describing the characteristic manufacturing method of the present invention, a liquid crystal display device will be 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 AA ′ of the liquid crystal display device of FIG.

  10A and 10B, in a liquid crystal display device 81 as an electro-optical device of this embodiment, a pair of TFT array substrate 82 and counter substrate 83 are thermosetting sealing materials. A liquid crystal layer made of liquid crystal 85 is provided which is bonded by a seal 84 and sealed in a region defined by the seal 84. The seal 84 is formed in a frame shape closed in a region within the substrate surface.

  A peripheral parting 86 for concealing the wiring with a light-shielding material is formed on the surface of the counter substrate 83 on the liquid crystal 85 side inside the seal 84. A data line driving circuit 87 and an electrode terminal 88 are formed along a side 82a (lower side in FIG. 10) of the TFT array substrate 82 at a location outside the seal 84, and a side 82b adjacent to the side 82a. A scanning line driving circuit 89 is formed along the side 82c (left and right sides in FIG. 10). The data line driving circuit 87, the electrode terminal 88, and the scanning line driving circuit 89 are electrically connected by a wiring 90a. On the remaining side 82d (upper side in FIG. 10) of the TFT array substrate 82, a wiring 90b for connecting the two scanning line driving circuits 89 is provided. In addition, inter-substrate conductive members 91 for providing electrical continuity between the TFT array substrate 82 and the counter substrate 83 are disposed at the four corners of the counter substrate 83. A counter electrode 92 is arranged on the counter array 83 side of the counter substrate 83 and is electrically connected to the inter-substrate conductive material 91. Further, an alignment film 93 is disposed on the TFT array substrate 82 side of the counter electrode 92.

  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. In addition, since light does not naturally enter the pixel where the light is blocked by the liquid crystal, it becomes 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 image can be displayed by blinking the pixel.

  In the region for displaying an image of the liquid crystal display device 81 having such a structure, a plurality of pixels 94 are arranged in a matrix of m rows and n columns, and a pixel signal is transmitted to each of these pixels 94. A TFT (Thin Film Transistor) which is a switching element for switching 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 A pixel electrode 96 is electrically connected to the pixel electrode 96. 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 96 is electrically connected to the drain electrode of the TFT, and the pixel signal supplied from the data line is applied to the pixel electrode 96 of each pixel 94 at a predetermined timing by turning on the TFT for a certain period. Supplied in. The voltage level of the pixel signal having a predetermined level supplied to the pixel electrode 96 in this way is held between the counter electrode 92 and the pixel electrode 96 of the counter substrate 83, and the liquid crystal 85 is set according to the voltage level of the pixel signal. The amount of transmitted light changes.

  An alignment film 97 is disposed on the counter substrate 83 side of the pixel electrode 96. The alignment film 93 and the alignment film 97 have groove-like irregularities formed on the surfaces thereof, and the liquid crystal 85 filled between the alignment film 93 and the alignment film 97 is formed between the alignment film 93 and the alignment film 97. It is formed by being arranged along the groove-shaped irregularities that are formed.

  In the TFT array substrate 82, a dustproof glass 98 is disposed on the surface opposite to the liquid crystal 85 via an adhesive 99. In the counter substrate 83, a dustproof glass 100 is disposed on the surface opposite to the liquid crystal 85. It is arranged via an adhesive 101. The dustproof glasses 98 and 100 prevent dust and dirt from adhering to the TFT array substrate 82 and the counter substrate 83. Further, even if dust adheres to the dustproof glasses 98 and 100, the distance between the dust and the dust and the liquid crystal is increased by the thickness of the dustproof glass. When an image formed by the pixel 94 of the liquid crystal display device 81 is projected by an externally arranged projection lens, the dust and the dust image are defocused and displayed on the screen in a largely blurred manner, so that the image becomes inconspicuous. it can.

  In the dustproof glass 98, an optical thin film 98a is formed on the surface opposite to the TFT array substrate 82, and in the dustproof glass 100, the optical thin film 100a is formed on the surface opposite to the counter substrate 83. The optical thin film 98a and the optical thin film 100a have a function of transmitting visible light and blocking ultraviolet light.

  A polarizing sheet is arranged on the optical axis of the light passing through the liquid crystal display device 81, and the amount of light transmitted through the liquid crystal display device 81 is changed by the action of the polarizing sheet and the liquid crystal 85.

(Manufacturing method of liquid crystal display device)
Next, a method for dividing the substrate in the above-described liquid crystal display device 81 will be described with reference to FIGS. FIG. 11 is a flowchart of a manufacturing method of a liquid crystal display device, and FIGS. 12 to 16 are diagrams illustrating a manufacturing method of the liquid crystal display device.

  In the flowchart of FIG. 11, step S61 corresponds to a light attenuation amount measuring step of the counter mother substrate, and is a step of measuring the amount of light after attenuation when transmitting the ultraviolet light on the surface where the counter mother substrate is to be divided. is there. Next, the process proceeds to step S62. Step S62 corresponds to a light attenuation amount measuring step of the TFT array mother substrate, and is a step of measuring the light amount after attenuation when transmitting the ultraviolet light on the surface where the TFT array mother substrate is to be divided. Step S61 and step S62 are combined to form the light attenuation measurement step of step S81. Next, the process proceeds to step S63. Step S63 corresponds to an assembling process and is an assembling process by sandwiching and bonding a liquid crystal between the counter mother substrate and the TFT array mother substrate. Next, the process proceeds to step S64.

  Step S64 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 S65. Step S65 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 S64 on the counter mother substrate. Next, the process proceeds to step S66.

  Step S66 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 S67. Step S67 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 S66 on the TFT array mother substrate. Step S64 to step S67 are combined to form step S82. Step S82 corresponds to a scribe process. Next, the process proceeds to step S68.

  Step S68 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 S69. Step S69 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 S68 on the TFT array mother substrate. Next, the process proceeds to step S70. Step S70 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 S71. Step S71 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 S70 in the counter mother substrate. Step S68 to step S71 are collectively referred to as step S83. Step S83 corresponds to a dividing step. The liquid crystal display device 81 is formed by the above process.

  Next, the manufacturing method will be described in detail with reference to FIGS. 12 to 16 in association with the steps shown in FIG. FIG. 12A and FIG. 12B are diagrams corresponding to step S61. FIG. 12A is a schematic plan view showing an opposing mother substrate on which a liquid crystal display device is partitioned. FIG. 12B is a schematic cross-sectional view along the line B-B ′ in FIG.

  As shown in FIGS. 12A and 12B, the opposing mother substrate 104 has an opposing large substrate 104a as a first substrate and a dust-proof large glass 104b as a second substrate joined by an adhesive 101. Yes. A counter electrode 92, an alignment film 93, and the like are formed on the surface of the counter large substrate 104a opposite to the dust-proof large glass 104b. A method for forming the counter mother substrate 104 is manufactured by a known method, and a description thereof will be omitted.

  In order to form the liquid crystal display device 81 shown in FIG. 10, the surfaces scheduled to divide the opposed mother substrate 104 are referred to as an H opposed cut surface 105 and a V opposed cut surface 106. The H-opposing cut surface 105 is a cut surface of the opposed mother substrate 104 indicated by a one-dot chain line, and is a cut surface extending in the X-axis direction of FIG. Reference numerals 105a, 105b, 105c, 105d, and 105e shown in FIG.

  The V opposing cutting surface 106 is a cutting surface of the opposing mother substrate 104 indicated by a one-dot chain line, and is a cutting surface extending in the Y-axis direction of FIG. Reference numerals 106a, 106b, and 106c shown in FIG.

  As shown in FIG. 12B, the light receiving device 13 is irradiated with ultraviolet light 15 from the light projecting device 14. Then, the ultraviolet light 15 is moved along the V facing cut surface 106, and the light attenuation amount at the V facing cut surface 106 is measured. Subsequently, the ultraviolet light 15 is moved along the H-opposed cut surface 105, and the light attenuation amount at the H-opposed cut surface 105 is measured. Then, the amount of light attenuation when irradiating the laser beam 7 is calculated and stored in the memory 28.

  FIG. 13A and FIG. 13B are diagrams corresponding to step S62. FIG. 13A is a schematic diagram showing an opposing mother substrate on which a liquid crystal display device is partitioned. FIG. 13B is a schematic cross-sectional view taken along line C-C ′ in FIG.

  As shown in FIGS. 13A and 13B, the TFT array mother substrate 107 has a TFT array large substrate 107a as a first substrate and a dust-proof large glass 107b as a second substrate joined by an adhesive 99. Has been. A pixel electrode 96, an alignment film 97, a data line driving circuit 87, a scanning line driving circuit 89, and the like are formed on the surface of the TFT array large substrate 107a opposite to the dust-proof large glass 107b. The method for forming the TFT array mother substrate 107 is manufactured by a known method, and a description thereof will be omitted.

In order to form the liquid crystal display device 81 shown in FIG. 10, the surfaces on which the TFT array mother substrate 107 is to be divided are referred to as an H element cut surface 108 and a V element cut surface 109.
The H element cut surface 108 is a cut surface of the TFT array mother substrate 107 indicated by a one-dot chain line, and is a cut surface extending in the X-axis direction of FIG. 108a, 108b, and 108c shown in FIG. 13A are H element cut surfaces 108, respectively.

  The V element cut surface 109 is a cut surface of the TFT array mother substrate 107 indicated by a one-dot chain line, and is a cut surface extending in the Y-axis direction of FIG. 109a, 109b, and 109c shown in FIG. 13A are V element cut surfaces 109, respectively.

  As shown in FIG. 13B, the light projecting device 14 irradiates the light receiving device 13 with ultraviolet light 15. Then, the ultraviolet light 15 is moved along the V element cutting surface 109 to measure the amount of light attenuation at the V element cutting surface 109. Subsequently, the ultraviolet light 15 is moved along the H element cut surface 108 to measure the amount of light attenuation at the H element cut surface 108. Then, the amount of light attenuation when irradiating the laser beam 7 is calculated and stored in the memory 28.

  FIG. 14A and FIG. 14B are diagrams corresponding to step S63. FIG. 14A is a schematic plan view showing a mother substrate, and FIG. 14B is a schematic cross-sectional view taken along the line D-D ′ of FIG. As shown in FIGS. 14A and 14B, the mother substrate 110 is formed by sealing the liquid crystal 85 between the TFT array mother substrate 107 and the counter mother substrate 104 and bonding them with a seal 84. ing. A plurality of TFT array substrates 82 are formed on the large TFT array substrate 107a, and a plurality of counter substrates 83 are formed on the opposing large substrate 104a. Since the dustproof glass 98 and the dustproof glass 100 are bonded to the TFT array substrate 82 and the counter substrate 83, respectively, the dustproof large format glass 107b and the dustproof large format are arranged on the TFT array large format substrate 107a and the counter large format substrate 104a. The glass 104b is joined and disposed.

  When assembling the TFT array mother substrate 107 and the opposing mother substrate 104, the H opposing cutting surface 105 and the H element cutting surface 108 are opposed to each other, and the V opposing cutting surface 106 and the V element cutting surface 109 are opposed to each other. I do. For example, the H facing cutting surface 105a is opposed to the H element cutting surface 108a, the H facing cutting surface 105c is opposed to the H element cutting surface 108b, and the H facing cutting surface 105e is opposed to the H element cutting surface 108c. Let it assemble.

  Similarly, for example, the V opposing cutting surface 106f is opposed to the V element cutting surface 109a, the V opposing cutting surface 106e is opposed to the V element cutting surface 109b, and the V opposing cutting surface 106d is the V element cutting surface. Assemble with 109c. In addition, the formation method of the mother substrate 110 is manufactured by a well-known method, and description is abbreviate | omitted.

  FIG. 15A to FIG. 15C are diagrams corresponding to step S64. As shown in FIG. 15A, the mother substrate 110 is placed on the stage 22 of the laser scribing apparatus 1. Subsequently, the mother substrate 110 is moved so that the light condensing unit 8 is located at a place opposite to the place where the laser beam 7 is irradiated on the V facing cut surface 106. The main computer 26 inputs the light attenuation amount data 33 from the memory 28, and then calculates the light irradiation amount using the light attenuation amount data 33. The laser light source 2 emits a laser beam 7 having a light quantity that enables irradiation with the calculated light irradiation amount. And the condensing part 8 condenses and irradiates the laser beam 7. FIG.

  A reforming portion 60 is formed in the condensing place 7 c where the laser beam 7 is focused and irradiated, and a crack portion 61 is formed in the center of the reforming portion 60. In the present embodiment, since quartz glass is used for the opposing large substrate 104a and the dust-proof large glass 104b, a cavity is formed in the crack portion 61. Even if a part of the laser beam 7 is absorbed by the adhesive 101 and the amount of light of the laser beam 7 is attenuated, the amount of the laser beam 7 is increased corresponding to the amount of light attenuation. It is surely formed.

  By repeating the above movement and irradiation, scribing is performed, the reforming portions 60 are arranged, and the first reforming portion 60a is formed along the V-opposing cut surface 106 of the opposed large substrate 104a. Subsequently, the reformer 60 is arranged at a location adjacent to the first stage to form a second-stage reformer 60b. In the third and subsequent stages, the reforming portions 60 are arranged and formed in the same manner. As a result, as shown in FIG. 15B, the reforming portion 60 is formed in an array on all the V facing cut surfaces 106 of the facing large substrate 104a, and a crack portion 61 is formed at the center of the reforming portion 60. It is formed. This series of steps is performed using the method described in the first embodiment.

  Subsequently, the adhesive 101 between the opposing large substrate 104a and the dust-proof large glass 104b is irradiated with the laser beam 7 along the V opposing cut surface 106, whereby the adhesive 101 is denatured and divided. Make it easy to do.

  Next, as shown in FIG. 15B, the modified portion 60 is arranged by moving the mother substrate 110 and irradiating the laser beam 7 along the V facing cut surface 106 of the dust-proof large format glass 104b. Form. As a result, as shown in FIG. 15C, the reforming portion 60 is formed in an array on all of the V facing cut surfaces 106 of the facing large substrate 104a and the dust-proof large format glass 104b. The crack part 61 is formed.

  In step S65, the laser beam 7 is irradiated along the H opposing cut surface 105 of the opposing mother substrate 104 to perform scribing. Subsequently, in step 66, the mother substrate 110 is inverted, and the laser beam 7 is irradiated along the V element cut surface 109 of the TFT array mother substrate 107 to perform scribing. Subsequently, in step S67, the laser beam 7 is irradiated along the H element cut surface 108 of the TFT array mother substrate 107 to perform scribing. The scribing method is the same as that in step S64, and detailed description thereof is omitted.

FIG. 16A to FIG. 16B are diagrams corresponding to step S68. As shown in FIG. 16A, the mother substrate 110 is placed on a base 111 made of an elastic material or the like. The dust-proof large-size glass 107b of the mother substrate 110 is disposed so as to be in contact with the base 111, and the pressure member 112 is disposed at a position facing the crack portion 61 formed in the H element cut surface 108 on the counter mother substrate 104. Press with. The TFT array mother substrate 107 sinks into the base 111, and tension acts on the crack portion 61. The TFT array mother substrate 107 breaks and breaks starting from the crack portion 61 close to the surface in contact with the base 111.
As a result, as shown in FIG. 16B, the TFT array mother substrate 107 is divided at the H element cut surface 108.

  In step S69, the crack portion 61 formed along the V element cutting surface 109 of the TFT array mother substrate 107 is divided. Subsequently, in step S <b> 70, the mother substrate 110 is inverted, and the crack portion 61 formed along the H-opposing cut surface 105 of the opposed mother substrate 104 is divided. Subsequently, in step S <b> 71, the crack portion 61 formed along the V-opposing cut surface 106 of the opposed mother substrate 104 is divided. The dividing method is the same as that in step S68, and detailed description thereof is omitted.

  Through the above steps, the mother substrate 110 is divided and formed into the shape of the liquid crystal display device 81 shown in FIG. 10A, and the liquid crystal display device 81 is completed.

As described above, this embodiment has the following effects.
(1) According to this embodiment, the laser beam 7 is irradiated using the method in the first embodiment. Therefore, even when the laser beam 7 is irradiated and scribed through the adhesives 99 and 101, the modified portion 60 is formed with high quality. Therefore, the counter mother substrate 104 and the TFT array mother substrate 107 are formed with high quality. Can be divided. As a result, a liquid crystal display device 81 including a substrate divided with high quality can be obtained.

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 embodiment, the ultraviolet light 15 is irradiated perpendicularly to the substrate 9 in step S2, but the ultraviolet light 15 may be irradiated obliquely to the substrate 9. At this time, since it passes through the layer of the adhesive 9c obliquely, the distance it passes becomes longer. Accordingly, the amount of light attenuation becomes large, and thus the amount of light attenuation when the ultraviolet light 15 is irradiated perpendicularly to the substrate 9 may be calculated by performing a correction operation. At this time, since the light receiving device 13 and the light projecting device 14 may be inclined, the arrangement of the light receiving device 13 and the light projecting device 14 can be easily designed.

(Modification 2)
In the first embodiment, the substrate 9 is irradiated with the ultraviolet light 15 to estimate the amount of light attenuation. However, the thickness of the first substrate 9a, the thickness of the second substrate 9b, and the thickness of the substrate 9 are determined. You may calculate the thickness of the adhesive agent 9c by measuring. Since a widely used thickness measuring device can be used, it is not necessary to arrange the light receiving device 13 and the light projecting device 14, and the laser scribing device 1 can be easily manufactured.

(Modification 3)
In the first embodiment, the light attenuation amount is calculated in step S3, and the light attenuation amount is stored in step S4. In step S7, when irradiating, the irradiation light amount with corrected light attenuation is calculated and irradiated. However, the present invention is not limited to this. In step S3, the light attenuation amount and the irradiation light amount corrected for the light attenuation amount may be calculated, and the light irradiation amount may be stored in step S4. In step S7, since the irradiation light quantity is already known, the time for calculating the irradiation light quantity can be shortened. As a result, since the processing time for irradiation can be shortened in step S7, processing can be performed with high productivity.

(Modification 4)
In the first embodiment, the measurement is performed along the first planned cutting plane 43 and then the laser beam 7 is irradiated. And it measures along the 2nd cutting plan surface 44, and the laser beam 7 is irradiated next. Without being limited thereto, the laser beam 7 may be irradiated along the first scheduled cutting surface 43 and the second scheduled cutting surface 44 after measurement along the first scheduled cutting surface 43 and the second scheduled cutting surface 44. good. By performing the irradiation of the laser light 7 collectively, the warm-up operation that stabilizes the light emission of the laser light source 2 can be performed once.

(Modification 5)
In the first embodiment, in step S7, the light attenuation amount is calculated by the linear equation using the light attenuation amount broken line 54 shown in FIG. 4B, but the second or higher order is calculated by the least square method. An equation may be obtained and calculated using this quadratic or higher order equation. The estimation of the light attenuation amount at each location between the measurement points can be calculated more accurately.

(Modification 6)
In step S3, as shown in FIG. 4A, the thickness of the adhesive is estimated from the light attenuation, and the light attenuation of the laser light 7 is estimated from the thickness of the adhesive. Not only this but the correlation table which shows the relationship between the light attenuation amount of the ultraviolet light 15 and the light attenuation amount in the laser beam 7 may be produced, and it may calculate using the correlation table. Since it does not take time to calculate the thickness of the adhesive, the light attenuation can be calculated with high productivity.

(Modification 7)
In the second embodiment, the light attenuation measured using the light receiving device 13 and the light projecting device 14 is all stored as the light attenuation data 33. Some data may be deleted after irradiation. As shown in FIG. 4B, the number of data that can be estimated for the distribution of the light attenuation amount 47 may be left. Since the capacity required for the memory 28 can be reduced by reducing the number of data, a resource-saving device can be obtained.

(Modification 8)
In the fourth embodiment, the counter mother substrate 104 and the TFT array mother substrate 107 are divided using the substrate dividing method in the first embodiment. However, in the second embodiment, the second embodiment, The substrate may be divided using the third embodiment and the above modification.

(Modification 9)
In the first to fourth embodiments, the YAG laser is used for 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 a modified portion 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. In this case, the condenser lens may be an objective lens having a magnification of 100, a numerical aperture (NA) of 0.8, and a WD (Working Distance) of 3 mm.

  (Modification 10) In the first embodiment, the main computer 26 stores the program software 29 in accordance with the operation procedure in the memory 28 and controls the laser laser scribing apparatus 1 with the program software 29. Not only this but you may control by the control apparatus comprised with an electric circuit. Peripheral devices may be controlled according to the procedure.

(Modification 11)
In the fourth embodiment, the substrate dividing method of the present invention is used for the liquid crystal display device 81, but it can also be used for electro-optical devices other than the liquid crystal display device 81. 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, it is possible to provide an electro-optical device including a substrate that is divided with high quality in the step of dividing the substrate.

(Modification 12)
In the first embodiment, the ultraviolet light 15 is irradiated and the amount of light after the light passing through the adhesive 9c is measured, but light having a wavelength other than the ultraviolet light 15 may be used. An LED with a long wavelength (Light Emitting Diode) is easier to manufacture than an LED with a shorter wavelength, and thus can be an easily manufactured device.

The schematic schematic diagram which shows the structure of the scribing apparatus according to the first embodiment. 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. 9 is a flowchart of a substrate cutting method according to the second embodiment. The figure explaining the division | segmentation method of a board | substrate. The schematic schematic diagram which shows the structure of the scribing apparatus according to the third embodiment. (A) is a schematic plan view of the liquid crystal display device which concerns on 4th Embodiment, (b) is a schematic cross section of a liquid crystal display device. The flowchart of the manufacturing method of a liquid crystal display device. 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. 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. 4A and 4B illustrate a method for manufacturing a liquid crystal display device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Laser light source as a laser light source part, 7 ... Laser light, 9a ... 1st board | substrate, 9b ... 2nd board | substrate, 9c ... Adhesive, 15 ... Ultraviolet light as measurement light, 39 ... Light as attenuation light quantity measurement part Attenuation measuring device 45 ... Measurement point as measurement location, 50 ... Light attenuation, 60 ... Modification part, 81 ... Liquid crystal display device as electro-optical device, 104a ... Counter large substrate as first substrate, 104b, 107b: Dust-proof large format glass as the second substrate, 107a: TFT array large format substrate as the first substrate.

Claims (9)

A substrate dividing method for dividing the first substrate, wherein the first substrate and the second substrate are bonded via an adhesive,
After the measurement light is irradiated to the adhesive located between the first substrate and the second substrate and the measurement light passes through the adhesive, the amount of the measurement light is attenuated. A light attenuation measurement step for measuring a light attenuation corresponding to the amount of light;
An irradiation step of irradiating the first substrate with laser light from the second substrate side to form a modified portion inside the first substrate;
A cutting step of pressing the modified portion to cut the first substrate,
In the irradiation step, when the laser beam passes through the adhesive, the laser beam is irradiated with a large amount of light at a place where the light attenuation amount is large compared to a place where the light attenuation amount is small. How to divide A method for dividing a substrate according to claim 1,
In the optical attenuation measurement step, the substrate is divided by irradiating the adhesive with laser light having substantially the same wavelength as the laser light irradiated in the irradiation step, and measuring the optical attenuation. A method for dividing a substrate according to claim 1,
The light attenuation measurement step includes: measuring light attenuation measurement step for measuring light attenuation by the adhesive by irradiating the adhesive with measurement light having a wavelength different from that of the laser light irradiated in the irradiation step; ,
Light for calculating the light attenuation amount of the laser light using correlation data between the light attenuation amount of the adhesive at the wavelength of the measurement light and the light attenuation amount at the wavelength of the laser light irradiated in the irradiation step. A substrate cutting method, comprising: an attenuation amount calculating step. A method for dividing a substrate according to claim 1,
After the light attenuation measurement step, a storage step of storing the light attenuation and the measurement location where the light attenuation was measured,
In the irradiating step, after calculating the light attenuation amount at the irradiation location using the memorized measurement location and the light attenuation amount in the storage step, the light attenuation amount is used to modify the reforming unit. A method for dividing a substrate, wherein the amount of laser light that can be formed is calculated and irradiated. A method for dividing a substrate according to claim 1,
A method for dividing a substrate, wherein the light attenuation measurement step and the irradiation step are performed in parallel. A laser scribing apparatus that irradiates a laser beam onto the first substrate, in which a first substrate and a second substrate are bonded via an adhesive,
After the measurement light is irradiated to the adhesive located between the first substrate and the second substrate and the measurement light passes through the adhesive, the amount of the measurement light is attenuated. An optical attenuation measurement unit for measuring the optical attenuation corresponding to the amount of light;
A light amount control unit for controlling the light amount of the laser light applied to the first substrate,
When the laser beam passes through the adhesive, the laser scribing device irradiates a laser beam with a large amount of light at a place where the light attenuation amount is large compared to a place where the light attenuation amount is small. The laser scribing device according to claim 6,
The optical attenuation measuring unit irradiates the adhesive with the laser light and measures the optical attenuation. The laser scribing device according to claim 6,
The light attenuation measuring unit is
Irradiating the adhesive with measurement light having a wavelength different from that of the laser light, and measuring light attenuation measurement unit for measuring light attenuation by the adhesive;
Using the correlation data between the light attenuation amount at the wavelength of the measurement light and the light attenuation amount that the laser light irradiated in the irradiation step attenuates when irradiating the same adhesive thickness, A laser scribing apparatus comprising: an optical attenuation amount calculating unit for calculating an optical attenuation amount. A method of manufacturing an electro-optical device having the first substrate in which a first substrate and a second substrate are bonded via an adhesive,
6. A method of manufacturing an electro-optical device, wherein the first substrate is divided using the substrate dividing method according to claim 1.

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