JP4710732B2 - Substrate and method for dividing the same, electro-optical device and method for manufacturing the same, and electronic device - Google Patents

Description

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

Patent Document 1 discloses a laser scribing method for irradiating a substrate with laser light to form a modified region (hereinafter referred to as a modified portion) inside the substrate in order to cut a light-transmitting substrate with high quality. Has been. 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 at the focal point 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.

  A display device such as a liquid crystal display device is often formed by using a pair of substrates having a rectangular outer shape and disposing a liquid crystal or a light emitting element between the pair of substrates. In the manufacturing method, an element mother substrate in which a plurality of patterns corresponding to a display device of a switching element such as a transistor are arranged and an opposing mother substrate in which a plurality of patterns corresponding to a display device such as a common electrode are arranged are bonded together and divided. This method is widely adopted.

JP 2002-192371 A

  When the element mother substrate and the counter mother substrate are bonded together and the modified mother part is formed by irradiating the counter mother substrate with laser light, a part of the laser light passes through the counter mother substrate and irradiates the element mother substrate. To do. The element mother board is provided with wiring, terminals, and the like, and may be damaged by the laser beam.

  The present invention has been made paying attention to such conventional problems, and its purpose is to prevent damage caused by laser light when laser scribing, a method for dividing the substrate, an electro-optical device, and a method for manufacturing the same, To provide electronic equipment.

  In order to solve the above-described problems, a substrate dividing method according to the present invention is a substrate dividing method for dividing a substrate, wherein a conductive film forming step for forming a conductive film that transmits laser light on the substrate, and a laser on the substrate are provided. A scribing step of irradiating light to form a modified portion in the substrate; and a cutting step of pressing the modified portion to divide the substrate. At least a part of the conductive film is a laser in the scribe step. It is formed where light is irradiated.

  According to this method for dividing a substrate, a conductive film that transmits laser light is formed on the substrate. The substrate has optical transparency, and is formed by arranging the modified portions by irradiating the inside of the substrate with laser light. In the dividing step, the modified portion is pressed to divide the substrate.

A conductive film is formed on the substrate. When the substrate is irradiated with laser light, part of the laser light may irradiate the conductive film. When the laser light irradiates the conductive film, the laser light passes through the conductive film, so that the conductive film is not easily damaged by the laser light. Therefore, the conductive film formed on the substrate is hardly damaged by the laser beam, and the substrate is scribed and divided.
Scribe indicates that the laser beam is condensed and irradiated inside the substrate and the modified portions are arranged.

  In order to solve the above-described problem, a substrate dividing method according to the present invention is a substrate dividing method in which a first substrate and a second substrate are bonded to each other, and the first substrate is divided. A conductive film forming step of forming a conductive film that transmits laser light on the substrate, a bonding step of bonding the first substrate and the second substrate, and irradiating the first substrate with laser light, A scribing step for forming a modified portion inside the substrate and a dividing step for pressing the modified portion to divide the first substrate. At least a part of the conductive film is irradiated with laser light in the scribe step. It is formed in the place irradiated.

  According to this method for dividing a substrate, a conductive film that transmits laser light is formed on the second substrate. The first substrate and the second substrate are joined, and the first substrate is scribed. The first substrate has light transparency, and is formed by irradiating the inside of the first substrate with laser light and arranging the modified portions. In the dividing step, the modified portion is pressed to divide the first substrate.

  When the first substrate is irradiated with laser light, the first substrate is light-transmitting, so that part of the laser light may pass through the first substrate. When the laser light passes through the first substrate, the passing laser light irradiates the second substrate. A conductive film that transmits laser light is formed over the second substrate. When the laser light that irradiates the second substrate irradiates the conductive film, the laser light passes through the conductive film. Is less susceptible to damage by laser light. Therefore, the conductive film formed on the second substrate is hardly damaged by the laser light, and the first substrate is scribed and divided.

  In the substrate cutting method of the present invention, the conductive film is an ITO film.

  According to the method for dividing the substrate, the conductive film is an ITO (Indium Tin Oxide) film. The ITO film has low resistance per unit area compared to other transparent conductive films such as zinc oxide, indium oxide, and tin oxide, so that current can easily flow and it is less susceptible to electromagnetic noise. . Therefore, a conductive film resistant to noise can be obtained.

  The substrate cutting method according to the present invention includes a metal film forming step of forming a metal film on the second substrate, and at least a part of the metal film is formed in a place where the laser beam is not irradiated in the scribing step. It is characterized by.

  According to this method for dividing a substrate, a metal film is formed in at least a part of the place where the conductive film of the second substrate is formed and where the laser beam is not irradiated. Where the metal film is formed, the metal film is not damaged by the laser light in a place where the laser light is not irradiated.

  Since the metal film has a lower electrical resistance than the ITO film, the voltage drop can be reduced when a current is passed through the film. Therefore, the power loss can be reduced as compared with the case where the current flowing place is formed of the ITO film.

  The substrate cutting method according to the present invention is characterized in that, in the scribing step, the modified portion is formed in the vicinity of at least one surface of the substrate.

  Here, “the vicinity of one surface” will be described. When the modified portion is formed by irradiating the laser beam in the thickness direction of the substrate, the length in the thickness direction of the substrate in the formed modified portion is defined as the modified portion length. “Near one surface” means a region where the distance from one surface of the substrate is within twice the length of the modified portion. Since the length of the modified portion varies depending on the intensity of the irradiated laser beam, “near one surface” also varies depending on the intensity of the irradiated laser beam.

  Further, “the modified portion is formed in the vicinity of at least one surface of the substrate” means that a part of the modified portion is formed in a region “in the vicinity of one surface”.

  According to this substrate dividing method, the modified portion is formed in the vicinity of one surface of the substrate. When the modified portion is formed in the vicinity of the surface of the substrate, the laser light is condensed in the vicinity of the surface, so that the conductive film formed in the place irradiated with the laser light is easily damaged. . However, since the conductive film has optical transparency, it is hardly damaged.

  In the substrate cutting method according to the present invention, the modified portion is formed in the vicinity of at least one surface of the first substrate in the scribing step.

  According to this substrate dividing method, the modified portion is formed in the vicinity of one surface of the first substrate. In the first substrate, when the modified portion is formed in the vicinity of the surface on the second substrate side, the laser light is condensed near the surface, so that the laser light easily passes through the first substrate. . When the laser light passes through the first substrate and irradiates the second substrate, the conductive film formed on the second substrate where the laser light is irradiated has light transparency. , Almost no damage.

  The modified portion is formed in the vicinity of at least one surface of the first substrate. When the substrate is divided, the substrate is divided along the modified portions formed in an array. When the modified part is formed in the vicinity of the surface of the substrate, the modified part is divided along the modified part. Since the modified portions are formed in an array and divided along the modified portion, the section to be divided is divided with less unevenness to the vicinity of the surface where the modified portion is formed.

  The substrate cutting method according to the present invention is characterized in that, in the scribing step, the laser beam is transmitted through the first substrate to irradiate the second substrate, and a modified portion is formed inside the second substrate. To do.

  According to the method for dividing the substrate, when the modified portion is formed inside the second substrate, the laser light is transmitted through the first substrate and irradiated on the second substrate. In the second substrate, a light-transmitting conductive film is formed at a place where the laser beam is irradiated. However, since the laser beam is transmitted, the second substrate is hardly damaged and the inside of the second substrate is not damaged. Irradiate. The first substrate and the second substrate are irradiated with laser light from the same first substrate side, and the modified portion is formed inside the first substrate and the second substrate. There is no need to invert the substrate and the second substrate. Therefore, it is possible to scribe with high productivity as compared with a case where a reversing process is required.

  In order to solve the above problems, a method for manufacturing an electro-optical device according to the present invention is a method for manufacturing an electro-optical device that joins a light-transmitting first substrate and a second substrate to divide the first substrate. A method is characterized in that the substrate is formed by using the substrate cutting method described above.

  According to this electro-optical device, the electro-optical device is formed by using the substrate cutting method described above. A light-transmitting conductive film is generated on the second substrate constituting the electro-optical device. When the first substrate is divided, the conductive film formed on the second substrate is less likely to be damaged by the laser light used to form the modified portion. Accordingly, when the first substrate is divided, the conductive film of the second substrate can be a method for manufacturing an electro-optical device that can prevent damage.

  In the electro-optical device manufacturing method of the present invention, the conductive film is a wiring.

  According to this electro-optical device, since the conductive film formed on the second substrate is a wiring, the wiring is a light-transmitting conductive film. Therefore, when the first substrate is divided, the method of manufacturing the electro-optical device can prevent the wiring of the second substrate from being damaged by the laser light applied to the first substrate.

  In the electro-optical device manufacturing method of the present invention, the conductive film is an electrode terminal.

  According to this electro-optical device, since the conductive film formed on the second substrate is an electrode terminal, the electrode terminal is a light-transmitting conductive film. Therefore, when the first substrate is divided, the electrode terminal of the second substrate can be a method for manufacturing an electro-optical device that can prevent damage.

  In the electro-optical device manufacturing method of the present invention, the electro-optical device has a switching element, and the conductive film is electrically connected to the switching element.

  According to this electro-optical device, the electro-optical device has the switching element. The switching element controls the current flowing through the display element by switching the current flow based on the electrical signal. Since the number of wirings can be reduced as compared with a method of forming wirings for supplying current to individual display elements, an electro-optical device that facilitates wiring design can be obtained.

  At least a part of the wiring for supplying an electrical signal to the switching element is formed of a light transmissive conductive film. Since the wiring formed of the light-transmitting conductive film is less likely to be damaged by the laser light when the first substrate is divided, an electro-optical device that can supply an electrical signal to the switching element with high quality can do.

  The substrate of the present invention is characterized by being divided by the substrate dividing method described above.

  According to this substrate, the substrate is divided by the above-described substrate dividing method. The substrate includes a first substrate and a second substrate, and a conductive film is formed on the second substrate. This conductive film is not easily damaged by the laser beam used when dividing the first substrate. Therefore, this substrate can be a substrate that can prevent the conductive film formed on the second substrate from being damaged.

  The electro-optical device of the present invention is manufactured using the above-described method for manufacturing an electro-optical device.

  According to this electro-optical device, the electro-optical device is manufactured using the above-described method for manufacturing an electro-optical device. The electro-optical device has a light-transmitting conductive film, and is a conductive film that is not easily damaged by laser light when the substrate is divided. Therefore, when the substrate is divided, the electro-optical device including the substrate that can prevent the conductive film formed on the substrate from being damaged can be obtained.

  According to another aspect of the invention, there is provided an electronic apparatus including the above-described electro-optical device in a display unit.

  According to this electronic apparatus, the electronic apparatus includes the electro-optical device described above. In this electro-optical device, when the substrate is scribed and divided using laser light, the conductive film formed on the substrate is a conductive film that is not easily damaged by the laser light. Therefore, the conductive film formed over the substrate is hardly damaged by the laser light. Therefore, an electronic apparatus including an electro-optical device including a conductive film that can be prevented from being damaged by laser light in a scribe process can be provided.

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 in which a light-transmitting conductive film is formed and scribed and divided by a laser scribe method will be described. Here, the laser irradiation apparatus will be described before describing the characteristic manufacturing method of the present invention.

(Laser irradiation device)
FIG. 1 is a schematic diagram showing a configuration of a laser irradiation apparatus.
As shown in FIG. 1, the laser irradiation apparatus 1 includes a laser light source 2 that emits laser light, an optical path unit 3 that irradiates the work with the emitted laser light, and a work relative to the optical path unit 3. The table unit 4 is moved mainly and the control device 5 for controlling the operation is 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 dichroic mirror 6. The dichroic mirror 6 is disposed on the optical axis 7 of the laser light emitted from the laser light source 2. The dichroic mirror 6 reflects the laser light emitted from the laser light source 2 and changes the traveling direction of the optical axis 7. A condenser lens 8 is disposed on the optical axis 7 through which the laser light reflected by the dichroic mirror 6 passes. A work 9 is arranged on the table 4, and the work 9 is irradiated with laser light that has passed through the condenser lens 8.

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

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

  An imaging device 12 is provided on the extension line of the optical axis 7 passing through the condenser lens 8 and the dichroic mirror 6 and on the opposite side of the condenser lens 8 with respect to the dichroic mirror 6. The imaging device 12 includes, for example, a coaxial incident light source and a CCD (Charge Coupled Device) (not shown). The visible light emitted from the coaxial incident light source passes through the condenser lens 8 and irradiates the work 9. The imaging device 12 can image the workpiece 9 through the condenser lens 8 and the dichroic mirror 6.

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

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

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

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

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

The laser control device 27 is a device that controls the pulse width of the pulse signal that drives the laser light source 2, the pulse cycle, the start and stop of output, and the like, and is controlled by the control signal of the main computer 24.
The lens control device 28 is a device that controls the movement and stop of the lens moving mechanism 11. The lens moving mechanism 11 has a built-in position sensor (not shown) that can detect the moving distance, and the lens control device 28 detects the output of the position sensor to detect the position of the condenser lens 8 in the direction of the optical axis 7. Recognize position. The lens control device 28 can transmit a pulse signal to the lens moving mechanism 11 to move the lens moving mechanism 11 to a desired position.

  The image processing device 29 has a function of calculating image data output from the imaging device 12. When the work 9 is placed on the stage 20 and an image taken by the imaging device 12 is observed, the lens moving mechanism 11 is operated to change the distance between the condenser lens 8 and the work 9 to make the image clearer. There are times when it is blurred. When the condenser lens 8 is moved to focus on the surface of the work 9 on the stage 20 side and when the work 9 is focused on the surface of the work 9 on the optical path unit 3 side, the image to be captured becomes clear. On the other hand, when the image is out of focus, the captured image is a blurred image.

  The thickness of the work 9 is measured by moving the condensing lens 8 in the direction of the optical axis 7 and detecting the position of the condensing lens 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 imaged by the imaging device 12 and the condensing position that is condensed by the condensing lens 8 when the laser beam is irradiated. And the offset distance, which is the difference between the condensing positions. For example, an object obtained by stacking two transparent substrates is set on the stage 20 as a workpiece 9 and the condenser lens 8 is moved so that the imaging device 12 is focused on a contact portion between the two substrates. Next, the modified portion is formed by irradiating laser light. The offset distance can be set by measuring the distance between the contact portion and the reforming portion of the two substrates.

  The condenser lens 8 is moved in the direction of the optical axis 7 so that the imaging device 12 is focused on the surface of the work 9 on the optical path portion 3 side. The moving distance of the condensing lens 8 is calculated from the position where the laser beam is to be irradiated and the offset distance, and the condensing lens 8 is moved by the distance corresponding to the calculated moving distance. With this method, the laser beam can be condensed to a predetermined depth in the workpiece 9.

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

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

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

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

  As for the irradiation condition of the laser beam for forming such a modified portion, it is necessary to set the output of the laser beam, the pulse width, the pulse period, the laser scan speed, etc. for each workpiece. In particular, it is necessary to consider that the output of the laser light emitted from the laser light source 2 is attenuated by absorption by a transmissive substance disposed on the optical axis 7 such as the dichroic mirror 6 and the condenser lens 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 4 are diagrams for explaining the substrate dividing method.

  In the flowchart of FIG. 2, step S <b> 1 corresponds to a conductive film forming step, and is a step of forming a conductive film that is transparent to laser light as a wiring and an electrode on the second substrate. Next, the process proceeds to step S2. Step S2 corresponds to a bonding step, and is a step of bonding the first substrate and the second substrate. Next, the process proceeds to step S3. Step S3 corresponds to a scribing process, and is a process of scribing by forming laser beam on the first substrate and irradiating the inside of the first substrate with the laser beam to form the modified portions. Next, the process proceeds to step S4. Step S4 corresponds to a dividing step, and is a step in which stress is applied to the reformed portions formed in an array and divided.

  Next, the manufacturing method will be described in detail with reference to FIGS. 3 to 4 in association with the steps shown in FIG. FIG. 3A is a schematic plan view of the bonded substrate formed in the present embodiment. FIG. 3B is a schematic side view of the bonded substrate viewed from the line A-A ′. As shown in FIGS. 3A and 3B, the bonding substrate 34 is formed by bonding a first substrate 35 and a second substrate 36 with an adhesive 37. The first substrate 35 includes a substrate 38, and the second substrate 36 includes a substrate 39. The substrate 38 and the substrate 39 are made of a material that is transmissive to laser light. In this embodiment, for example, quartz glass is employed.

  In the second substrate 36, a pair of electrode terminals 40 a and 40 b are formed on the surface of the substrate 39 in a direction orthogonal to the longitudinal direction of the substrate 39 and are electrically connected by a wiring 41 as a conductive film. Similarly, electrode terminals 42 a and 42 b as a pair of conductive films are formed next to the electrode terminals 40 a and 40 b and are electrically connected by the wiring 43. The electrode terminals 40a, 40b, 42a, 42b and the wirings 41, 43 are formed of a conductive film that is transparent to laser light. The light-transmitting conductive film may be a zinc oxide-based, indium oxide-based, tin oxide-based film or the like having a thickness that allows light to be transmitted. In this embodiment, for example, an ITO (Indium Tin Oxide) film is used. ing.

  A three-terminal transistor 44 and a transistor 45 are formed on the surface of the substrate 39. The transistor 44 and the transistor 45 are electrically connected by a wiring 46a. An electrode terminal 47 and an electrode terminal 48 are disposed on the end surface 39 a side of the substrate 39. The electrode terminal 47 and the transistor 44 are electrically connected via a wiring 46 b and a wiring 49. Similarly, the electrode terminal 48 and the transistor 45 are electrically connected via a wiring 46e and a wiring 50.

  An electrode terminal 51 and an electrode terminal 52 are disposed on the end surface 39 a side of the substrate 39. The electrode terminal 51 is electrically connected to the transistor 44 via the wiring 46c, and the electrode terminal 52 is electrically connected to the transistor 45 via the wiring 46d.

  An electrode terminal 53 is disposed on the end face 39 b side of the substrate 39, and the electrode terminal 53 and the transistor 44 and the transistor 45 are electrically connected via a wiring 46 a and a wiring 54.

  The wirings 46a to 46e as the metal films, the electrode terminals 47, the electrode terminals 48, and the electrode terminals 53 are formed of a film made of metal. In this embodiment, for example, aluminum is employed. Further, the wiring 49, the wiring 50, the wiring 54, the electrode terminal 51, and the electrode terminal 52 as a conductive film are formed of a conductive film that is transparent to laser light. In this embodiment, for example, an ITO film is used as the light transmissive conductive film.

  FIG. 3C and FIG. 3D are diagrams corresponding to step S1. FIG. 3C is a plan view of the substrate 39, and FIG. 3D is a side view of the substrate 39. As shown in FIGS. 3C and 3D, transistors 44 and 45, electrode terminals 40a, 40b, 42a, 42b, 47, 48, 51, 52, and 53, and wiring 41, 43, 46a to 46e, 49, 50, 54 are formed. A method for forming the transistors 44, 45, the electrode terminals 40a, 40b, 42a, 42b, 47, 48, 51, 52, 53 and the wirings 41, 43, 46a to 46e, 49, 50, 54 is a photolithography method or the like. The known method can be used, and the description is omitted.

  A line corresponding to the line divided by the substrate 38 shown in FIG. 3A is set as a division planned line, and the division planned line dividing the substrate 38 is shown as a division planned line 55a and a division planned line shown in FIG. 55b. The planned dividing line 55a and the planned dividing line 55b are virtual lines extending in the longitudinal direction of the substrate 39, and are lines indicated by alternate long and short dash lines.

  FIG. 3E and FIG. 4A are diagrams corresponding to step S2. As shown in FIG. 3E, an adhesive 37 is applied to the substrate 39. The adhesive 37 is applied to a region sandwiched between the planned split line 55a and the planned split line 55b shown in FIG. The application method is only required to apply the application thickness and the application position with high accuracy. In this embodiment, for example, a screen printing method is adopted. The adhesive 37 may be any adhesive that can bond the substrates to each other, and is selected according to the material of the substrate. In the present embodiment, for example, an epoxy adhesive is employed for the adhesive 37.

  As shown in FIG. 4A, the substrate 38 is placed and pressed on the adhesive 37 applied to the substrate 39. Subsequently, the bonding substrate 34 formed by pressing is dried to solidify the adhesive 37.

  4B and 4C are diagrams corresponding to step S3. As shown in FIG. 4B, the substrate 38 is irradiated with the laser beam 56 condensed by the condenser lens 8. Inside the substrate 38, a modified portion 57 is formed at a place where the laser beam 56 is irradiated. A cracked portion 58 that is a cavity is formed in the central portion of the modified portion 57.

  The condensing lens 8 and the substrate 38 are moved relative to each other to irradiate the inside of the substrate 38 with the laser light 56 and form the modified portions 57 in an array. In the substrate 38, a first-stage modified portion 57a is formed at a location near the surface 38a on the second substrate 36 side. It is desirable that the first-stage modified portion 57a is formed in the vicinity so that the crack portion 58 does not intersect the surface 38a. It is desirable that at least the distance between the crack part 58 and the surface 38a be within 10 times the length of the crack part 58 in the longitudinal direction. It is further desirable that the distance between the crack portion 58 and the surface 38a is within twice the length of the crack portion 58 in the longitudinal direction (near the surface).

  A second-stage modified portion 57b is formed at a location adjacent to the formed first-stage modified portion 57a in the thickness direction of the substrate 38. The second-stage modified portion 57b is also condensed and irradiated with the laser beam 56 from the condensing lens 8 inside the substrate 38 to form the second-stage modified portion 57b. Similarly, the third row and the fourth row are arranged so as to overlap the number of rows.

  As a result, as shown in FIG. 4C, a surface on which the reforming portions 57 are arranged is formed. The laser beam 56 is irradiated along the planned split line 55a and the planned split line 55b shown in FIG. As a result, a scribe surface 59a formed along the planned dividing line 55a and a scribe surface 59b formed along the planned divided line 55b are formed.

  FIG. 4D is a diagram corresponding to step S4. As shown in FIG. 4D, the first substrate 35 is disposed on a base 60 made of an elastic material. A place facing the scribe surface 59 a formed on the planned dividing line 55 a is pressed using the pressing member 61. The substrate 38 sinks into the table 60 and tension acts on the crack portion 58. The substrate 38 breaks and breaks starting from the crack portion 58 close to the surface in contact with the table 60.

  Similarly, a place facing the scribe surface 59 b formed on the planned dividing line 55 b is pressed using the pressing member 61. The substrate 38 sinks into the table 60 and tension acts on the crack portion 58. The substrate 38 breaks and breaks starting from the crack portion 58 close to the surface in contact with the table 60.

  As shown in FIG. 3B, as a result, the first substrate 35 is divided by the scribe surface 59a and the scribe surface 59b shown in FIG.

As described above, this embodiment has the following effects.
(1) According to this embodiment, in the second substrate 36, the electrode terminals 42a, 42b, 51, 52 and the wirings 41, 49, 50, 54 are formed of a conductive film that transmits laser light. When irradiating the first substrate 35 with the laser beam 56, the first substrate 35 is light transmissive, so that part of the laser beam 56 may pass through the first substrate 35. When the laser beam 56 passes through the first substrate 35, the passing laser beam 56 irradiates the second substrate 36. In the second substrate 36, electrode terminals 42 a, 42 b, 51, 52 and wirings 41, 49 formed of a conductive film that transmits the laser light 56 are disposed at locations facing the planned dividing lines 55 a and 55 b. , 50, 54 are arranged. When the laser beam 56 irradiating the second substrate 36 irradiates the electrode terminals 42a, 42b, 51, 52 and the wirings 41, 49, 50, 54, the laser beam 56 is applied to the electrode terminals 42a, 42b, 51, 52, and Since the wires 41, 49, 50, 54 pass through, the electrode terminals 42 a, 42 b, 51, 52 and the wires 41, 49, 50, 54 are not easily damaged by the laser beam 56. Therefore, the electrode terminals 42a, 42b, 51, 52 and the wirings 41, 49, 50, 54 formed on the second substrate 36 are hardly damaged by the laser beam 56, and the first substrate 35 is scribed. And divided.

  (2) According to this embodiment, the electrode terminals 40a, 40b, 42a, 42b, 51, 52 and the wirings 41, 43, 49, 50, 54 are formed of a conductive film. In the present embodiment, the conductive film employs an ITO film. The ITO film has low resistance per unit area compared to other transparent conductive films such as zinc oxide, indium oxide, and tin oxide, so that current can easily flow and it is less susceptible to electromagnetic noise. . Therefore, a conductive film resistant to noise can be obtained.

  (3) According to the present embodiment, the electrode terminals 47, 48, 53 and the wirings 46a to 46e made of a metal film are formed on the second substrate 36 where the laser beam is not irradiated. Since the laser beam 56 is not irradiated to the locations where the electrode terminals 47, 48, 53 and the wirings 46 a to 46 e are formed, the electrode terminals 47, 48, 53 and the wirings 46 a to 46 e are damaged by the laser beam 56. Not receive.

  Since the metal film has a lower electrical resistance than the ITO film, the voltage drop can be reduced when a current is passed through the film. Therefore, the power loss can be reduced as compared with the case where the current flowing place is formed of the ITO film.

  (4) According to the present embodiment, the modified portion 57 is formed at a location near the surface 38 a of the first substrate 35. In the first substrate 35, when the first modified portion 57a is formed at a location close to the surface 38a on the second substrate 36 side, the laser beam 56 is condensed at a location close to the surface 38a. The light 56 easily passes through the first substrate 35. When the laser beam 56 passes through the first substrate 35 and irradiates the second substrate 36, the conductive film formed on the second substrate 36 where the laser beam 56 is irradiated is light transmissive. Because of its properties, it is less susceptible to damage.

  The modified portion 57 is formed at a location close to at least one surface 38 a of the first substrate 35. When the first substrate 35 is divided along the modified portion 57, the modified section 57 is formed up to a place close to the surface 38a.

(Second Embodiment)
Next, an embodiment of a substrate cutting method embodying the present invention will be described with reference to FIGS. 2 and 5 to 7. FIG. 2 is a flowchart of the substrate dividing method, and FIGS. 5 to 7 are diagrams for explaining the substrate dividing method. The second embodiment is different from the first embodiment in that, in addition to the first substrate, the second substrate is scribed and divided using laser light.

  In the flowchart of FIG. 2, the contents of each step are the same as those in the first embodiment, and a description thereof will be omitted.

  FIG. 5A is a diagram corresponding to step S1 and corresponding to FIG. 3C in the first embodiment. As shown in FIG. 5A, two identical patterns are formed side by side on the second substrate 65. Further, in FIG. 3C of the first embodiment, electrode terminals 47, 48 and 53 made of a metal film are formed on the substrate 39. On the other hand, in FIG. 5A of the second embodiment, the second substrate 65 has electrode terminals 66, 67, 68 as conductive films made of an ITO film which is a light-transmitting conductive film on the substrate 69. Is formed.

  In step S2, a planned line for dividing the first substrate 72 to be bonded is set, and set as the planned divided lines 70a, 70b, 70c, and 70d. Similarly, a planned line for dividing the second substrate 65 is set as a planned divided line 71. The planned split line 70a to the planned split line 70d and the planned split line 71 are imaginary lines extending in the longitudinal direction of the substrate 69, and are lines indicated by alternate long and short dash lines.

  FIG. 5B is a diagram corresponding to step S2. An adhesive 37 is applied to the substrate 69. The adhesive 37 is applied to a region sandwiched between the planned split line 70a and the planned split line 70b and a region sandwiched between the planned split line 70c and the planned split line 70d. Subsequently, the first substrate 72 and the second substrate 65 are bonded and dried. The first substrate 72 has a light-transmitting property and has the same outer dimensions as the substrate 69.

  FIG. 5C and FIG. 6A to FIG. 6C are diagrams corresponding to step S3. As shown in FIG. 5C, the laser beam 56 is condensed using the condensing lens 8 and irradiated to the inside of the substrate 69. A modified portion 57 is formed at a place where the laser beam 56 is condensed and irradiated, and a crack portion 58 is formed at the center of the modified portion 57. The condenser lens 8 and the substrate 69 are moved relative to each other, and the modified portions 57 are arranged and formed. The laser beam 56 is irradiated along the planned dividing line 71 shown in FIG. 5A, and the modified portions 57 are formed in multiple stages in the thickness direction of the substrate 69 along the planned dividing line 71.

  As a result, as shown in FIG. 6A, a scribe surface 73 in which the reforming portions 57 are arranged in multiple stages is formed along the planned dividing line 71.

  Next, as shown in FIG. 6B, the laser beam 56 is condensed using the condensing lens 8 and irradiated to the inside of the first substrate 72. The laser beam 56 is irradiated along the planned dividing line 70a to the planned dividing line 70d shown in FIG. 5 (a), and the reforming unit 57 performs the first substrate 72 along the planned divided line 70a to the planned dividing line 70d. Are formed in multiple stages in the thickness direction.

  As shown in FIG. 6 (c), as a result, the reforming portion 57 is formed in multiple stages along the planned dividing line 70a to 70d, and corresponding to the planned dividing line 70a to 70d. Scribe surfaces 74a to 74d are formed.

  FIG. 7A and FIG. 7B are diagrams corresponding to step S4. As shown in FIG. 7A, the substrate 69 is placed on a base 60 made of an elastic material. A place facing the scribe surface 73 formed along the planned dividing line 71 is pressed using the pressing member 61. The substrate 69 sinks into the table 60, and tension acts on the crack portion 58. The substrate 69 breaks and breaks starting from the crack portion 58 close to the surface in contact with the table 60.

  Next, as shown in FIG. 7B, the first substrate 72 is placed on the base 60 made of an elastic material. A place facing the scribe surface 74 a to the scribe surface 74 d formed along the planned dividing line 70 a to 70 d is pressed using the pressing member 61. The first substrate 72 sinks into the table 60 and tension acts on the crack portion 58. The first substrate 72 breaks and breaks starting from the crack portion 58 close to the surface in contact with the table 60. Through the above steps, the first substrate 72 and the second substrate 65 are bonded, divided, and separated.

As described above, according to the present embodiment, in addition to the effects (1) to (4) in the first embodiment, the following effects are obtained.
(1) According to the present embodiment, when the modified portion 57 is formed inside the second substrate 65, the laser beam 56 passes through the first substrate 72 and irradiates the second substrate 65. In the second substrate 65, electrode terminals 40a, 40b, 42a, 42b, 51, 52, 66, 67, and 68 made of a light-transmitting conductive film are formed at locations where the laser beam 56 is irradiated. . The electrode terminals 40 a, 40 b, 42 a, 42 b, 51, 52, 66, 67, 68 are hardly damaged because they transmit the laser light 56, and the laser light 56 irradiates the inside of the second substrate 65. To do. The first substrate 72 and the second substrate 65 are irradiated with laser light 56 from the same first substrate 72 side, and a modified portion 57 is formed inside the first substrate 72 and the second substrate 65. Therefore, it is not necessary to invert the first substrate 72 and the second substrate 65. Therefore, since the inversion process is not required, scribing can be performed with high productivity.

(Third 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 of the present invention will be described. Here, before describing the characteristic manufacturing method of the present invention, the liquid crystal display device will be sequentially described.

(Liquid crystal display device)
First, a liquid crystal display device will be described. FIG. 8 is a schematic plan view of the liquid crystal display device, and FIG. 9 is a schematic cross-sectional view taken along the line BB ′ of the liquid crystal display device of FIG.

  8 and 9, a liquid crystal display device 81 as an electro-optical device according to this embodiment has a TFT array substrate 82 and a counter substrate 83 that form a pair, which are bonded together by a seal 84 that is a thermosetting sealing material. A liquid crystal layer made of liquid crystal 85 is provided 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. 8) of the TFT array substrate 82 at a location outside the seal 84, and a side 82b adjacent to the side 82a. The scanning line driving circuit 89 is formed along the side 82c (the left and right sides in FIG. 8). The data line driving circuit 87, the electrode terminal 88, and the scanning line driving circuit 89 are electrically connected by a wiring 90a that is a light transmissive conductive film. On the remaining side 82 d (upper side in FIG. 8) of the TFT array substrate 82, a wiring 90 b that is a light-transmitting conductive film for connecting the two scanning line driving circuits 89 is provided. The electrode terminal 88 and the wirings 90a and 90b may be any conductive film that is transparent to laser light. In this embodiment, for example, an ITO film is employed. 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.

  The liquid crystal display device 81 is configured for color display. On the counter substrate 83, red (R), green (G), and blue (B) color filters 92R, 92G, and 92B are formed together with a protective film. Yes. A light shielding film 93 is formed between the filter elements of the color filters 92R, 92G, and 92B. The light shielding film 93 blocks light that does not pass through the color filters 92R, 92G, and 92B. Further, a counter electrode 94 and an alignment film 95 are disposed on the TFT array substrate 82 side of the protective film of the color filters 92R, 92G, and 92B.

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

  In the region for displaying an image of the liquid crystal display device 81 having such a structure, a plurality of pixels are configured in a matrix of m rows and n columns, and a pixel signal is switched to each of these pixels. A TFT (Thin Film Transistor) which is a switching element is formed. A data line (source wiring) for supplying a pixel signal is electrically connected to the source electrode of the TFT, a scanning line (gate wiring) for supplying a scanning signal is electrically connected to the gate electrode of the TFT, and a drain electrode of the TFT A pixel electrode 96 is electrically connected to the pixel electrode 96. The pixel electrode 96 is formed at a location facing the filter elements of the color filters 92R, 92G, and 92B. 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. By turning on the TFT for a certain period, the pixel signal supplied from the data line is applied to the pixel electrode 96 of each pixel at a predetermined timing. Supplied. The voltage level of the pixel signal of the predetermined level supplied to the pixel electrode 96 in this way is held between the counter electrode 94 of the counter substrate 83 shown in FIG. 9, and the liquid crystal 85 is set according to the voltage level of the pixel signal. The amount of transmitted light changes. The liquid crystal display device 81 includes a color filter, and the liquid crystal display device 81 is controlled by an image signal applied to an electrode that sandwiches a liquid crystal layer made of the liquid crystal 85 by transmitting light transmitted through the color filters 92R, 92G, and 92B. A color image can be displayed.

  An alignment film 97 is disposed on the counter substrate 83 side of the pixel electrode 96. The alignment film 95 and the alignment film 97 have groove-like irregularities formed on the surfaces thereof, and the liquid crystal 85 filled between the alignment film 95 and the alignment film 97 is arranged along the groove-like irregularities. Formed.

  In the TFT array substrate 82 and the counter substrate 83, polarizing sheets 98 and 99 are disposed on the surface opposite to the liquid crystal 85, and light transmission that passes through the liquid crystal display device 81 by the action of the polarizing sheets 98 and 99 and the liquid crystal 85. The amount is changing.

(Manufacturing method of liquid crystal display device)
Next, a method for dividing the substrate in the above-described liquid crystal display device 81 will be described with reference to FIGS. FIG. 10 is a flowchart of a manufacturing method of a liquid crystal display device, and FIGS. 11 to 17 are diagrams illustrating a manufacturing method of the liquid crystal display device.

  In the flowchart of FIG. 10, step S11 corresponds to a process for forming elements, wirings, and electrodes on the TFT array mother substrate, and is a process for forming elements, wirings, electrodes, and the like on the TFT array mother substrate. Next, the process proceeds to step S12. Step S12 corresponds to a bonding process, and is a process for bonding the TFT array mother substrate and the counter mother substrate. Next, the process proceeds to step S13. Step S13 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 S14. Step S14 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 S13 on the counter mother substrate. Next, the process proceeds to step S15.

  Step S15 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 S16. Step S16 corresponds to a second scribing step for the TFT array mother substrate, and is a step for scribing the TFT array mother substrate in a direction orthogonal to the direction scribed in step S15. Next, the process proceeds to step S17. Step S <b> 17 corresponds to a process of dividing the counter mother substrate, and is a process of dividing the counter mother substrate. Next, the process proceeds to step S18. Step S18 corresponds to a TFT array mother substrate dividing step, and is a step of dividing the TFT array mother substrate. 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. 11 to 17 in association with the steps shown in FIG. FIG. 11A is a schematic diagram showing a TFT array mother substrate which is a mother substrate in which the TFT array substrate is partitioned. FIG. 11B is a schematic cross-sectional view taken along line C-C ′ of FIG.

  FIG. 11A and FIG. 11B are diagrams corresponding to step S11. As shown in FIGS. 11A and 11B, a TFT array mother substrate 102 as a substrate and a second substrate is formed in a disk shape on one surface 103a of a substrate 103. An alignment film 97 is formed so as to cover the pixel electrode 96, and an alignment process for forming irregularities on the surface is performed. The substrate 103 only needs to be a light-transmitting material. For example, quartz glass is used in this embodiment.

  On the TFT array mother substrate 102, TFTs (not shown) are formed in correspondence with the pixel electrodes 96, and the pixel electrodes 96 and the TFTs are electrically connected. A data line driving circuit 87 and a scanning line driving circuit 89 that transmit signals to the TFT are formed, and a wiring 104 that electrically connects the TFT to the data line driving circuit 87 and the scanning line driving circuit 89 is formed. . The wiring 104 is made of aluminum as a material. An electrode terminal 88 for inputting a signal from the outside to the data line driving circuit 87 and the scanning line driving circuit 89 is formed, and the data line driving circuit 87, the scanning line driving circuit 89, and the electrode terminal 88 are electrically connected. A wiring 90a to be connected is formed. The wirings 90a and 90b and the electrode terminal 88 are formed of a light-transmitting conductive film. In this embodiment, an ITO film is used as the conductive film.

  The above circuits, elements, wirings and the like formed on the TFT array mother substrate 102 are manufactured by a known method, and a description thereof will be omitted.

  12 to 13 are diagrams corresponding to step S12. As shown in FIG. 12A, a sealing material 105 is applied to the substrate 103. The sealing material 105 may be any material that can adhere to the substrate when solidified and does not affect the liquid crystal. In this embodiment, a thermosetting epoxy resin is used. The sealing material 105 is applied in a frame shape like a seal 84 shown in FIG.

  As shown in FIG. 12B, on the substrate 103, the liquid crystal 85 is applied using a dispenser inside the sealing material 105 applied in a frame shape. The substrate 103 coated with the liquid crystal 85 is placed in a vacuum chamber (not shown), and the inside of the vacuum chamber is evacuated to make a vacuum.

  FIG. 13A is a schematic diagram illustrating a mother substrate, and FIG. 13B is a schematic cross-sectional view taken along the line D-D ′ of FIG. As shown in FIG. 13A and FIG. 13B, in the vacuum chamber that is evacuated, the opposing mother substrate 106 as the first substrate and the TFT array mother substrate 102 are pressed in alignment. On the counter mother substrate 106, color filters 92R, 92G, and 92B, a light shielding film 93, and a counter electrode 94 shown in FIG. After the opposing mother substrate 106 is pressed against the TFT array mother substrate 102, air flows into the vacuum chamber. The TFT array mother substrate 102 and the opposing mother substrate 106 are pressurized by the atmospheric pressure.

  The sealing material 105 is solidified to form a seal 84 by heating and drying in a state where the relative position between the counter mother substrate 106 and the TFT array mother substrate 102 is maintained. The mother substrate 108 in which the counter mother substrate 106 and the TFT array mother substrate 102 are bonded via the seal 84 is completed, and Step S12 is completed.

In order to form the liquid crystal display device 81 shown in FIG. 8, the surfaces on which the opposed mother substrate 106 is to be divided are referred to as an H opposed cutting surface 109 and a V opposed cutting surface 110, and the surfaces on which the TFT array mother substrate 102 is to be divided are formed. They are denoted as H element cut surface 111 and V element cut surface 112.
The H facing cut surface 109 is a cutting surface of the facing mother substrate 106 indicated by a one-dot chain line, and is a cutting surface extending in the X-axis direction of FIG. 109a, 109b, 109c, 109d, and 109e shown in FIG. 13A are H-opposing cut surfaces 109, respectively.

  The V opposing cutting surface 110 is a cutting surface of the opposing mother substrate 106 indicated by a one-dot chain line, and is a cutting surface extending in the Y-axis direction of FIG. Reference numerals 110a, 110b, and 110c shown in FIG.

  The H element cut surface 111 is a cut surface of the TFT array mother substrate 102 indicated by a one-dot chain line, and is a cut surface extending in the X-axis direction of FIG. 111a, 111b, and 111c shown in FIG. 13A are H element cut surfaces 111, respectively.

  The V element cut surface 112 is a cut surface of the TFT array mother substrate 102 indicated by a one-dot chain line, and is a cut surface extending in the Y-axis direction of FIG. The V element cutting surface 112 is located at a position facing the V facing cutting surface 110, and 112a, 112b, and 112c shown in FIG. 13A are V element cutting surfaces 112, respectively.

  FIG. 14A to FIG. 14B are diagrams corresponding to step S13. As shown in FIG. 14A, the laser light 56 is condensed and irradiated by the condenser lens 8 inside the substrate 107 of the counter mother substrate 106. A modified portion 57 is formed at a place where the laser beam 56 is condensed and irradiated, and a crack portion 58 is formed at the center of the modified portion 57. The condensing lens 8 and the substrate 107 are relatively moved to irradiate the laser beam 56, and the modified portions 57 are arranged and formed. First, in the substrate 107, the modified portion 57 is arranged near the surface 107 b on the TFT array mother substrate 102 side, and the first modified portion 57 a is formed along the V facing cut surface 110 of the substrate 107. Subsequently, the reformer 57 is arranged at a location adjacent to the first stage to form the second-stage reformer 57b. In the third and subsequent stages, the reforming portions 57 are arranged and formed in the same manner.

  As shown in FIG. 13A, in the TFT array mother substrate 102, the wiring 90a and the wiring 90b are formed in the vicinity of the place facing the V facing cut surface 110. When the laser beam 56 is irradiated along the V-opposing cut surface 110, the laser beam 56 that passes through the counter mother substrate 106 may irradiate the wiring 90a and the wiring 90b. Since the wiring 90a and the wiring 90b are formed of a light-transmitting conductive film, the laser light 56 passes through the wiring 90a and the wiring 90b. Therefore, the wiring 90 a and the wiring 90 b are not easily damaged by the laser beam 56.

  As a result, as shown in FIG. 14B, the modified portion 57 is formed in an array on all the V facing cut surfaces 110 of the substrate 102, and a crack portion 58 is formed in the center of the modified portion 57. .

  14 (c) to 14 (d) are diagrams corresponding to step S14. As shown in FIG. 14C, the laser light 56 is condensed and irradiated by the condenser lens 8 inside the substrate 107 of the counter mother substrate 106. A modified portion 57 is formed at a place where the laser beam 56 is condensed and irradiated, and a crack portion 58 is formed at the center of the modified portion 57. Similarly to step S13, the condenser lens 8 and the substrate 107 are moved relative to each other and irradiated with the laser light 56, and the modified portions 57 are formed along the H-opposing cut surface 109 of the substrate 107. .

  As shown in FIG. 13A, in the TFT array mother substrate 102, an electrode terminal 88 and a wiring 90b are formed near a place facing the H-opposing cut surface 109. When irradiating the laser beam 56 along the H-opposing cut surface 109, the laser beam 56 passing through the opposing mother substrate 106 may irradiate the electrode terminal 88 and the wiring 90b. Since the electrode terminal 88 and the wiring 90b are formed of a light-transmitting conductive film, the laser light 56 passes through the electrode terminal 88 and the wiring 90b. Therefore, the electrode terminal 88 and the wiring 90 b are not easily damaged by the laser beam 56.

  As a result, as shown in FIG. 14 (d), the modified portion 57 is formed in an array on all the H facing cut surfaces 109 of the substrate 106, and a crack portion 58 is formed in the center of the modified portion 57. .

  15A to 15B are diagrams corresponding to step S15. As shown in FIG. 15A, the laser beam 56 is condensed and irradiated by the condenser lens 8 inside the substrate 103 of the TFT array mother substrate 102. A modified portion 57 is formed at a place where the laser beam 56 is condensed and irradiated, and a crack portion 58 is formed at the center of the modified portion 57. Similarly to step S13, the condenser lens 8 and the substrate 103 are moved relative to each other and irradiated with the laser beam 56, and the modified portions 57 are formed along the V element cut surface 112 of the substrate 103. .

  As shown in FIG. 13A, in the TFT array mother substrate 102, wiring 90 a and wiring 90 b are formed near the V element cut surface 112. When irradiating the laser beam 56 along the V element cut surface 112, the laser beam 56 passing through the TFT array mother substrate 102 may irradiate the wiring 90a and the wiring 90b. Since the wiring 90a and the wiring 90b are formed of a light-transmitting conductive film, the laser light 56 passes through the wiring 90a and the wiring 90b. Therefore, the wiring 90 a and the wiring 90 b are not easily damaged by the laser beam 56.

  As a result, as shown in FIG. 15B, the modified portion 57 is formed and arranged on the entire V element cutting surface 112 of the substrate 103, and the crack portion 58 is formed at the center of the modified portion 57. .

  FIGS. 15C to 15D are diagrams corresponding to step S16. As shown in FIG. 15C, the laser beam 56 is condensed and irradiated by the condenser lens 8 inside the substrate 103 of the TFT array mother substrate 102. A modified portion 57 is formed at a place where the laser beam 56 is condensed and irradiated, and a crack portion 58 is formed at the center of the modified portion 57. Similarly to step S <b> 13, the condenser lens 8 and the substrate 103 are moved relative to each other and irradiated with the laser beam 56, and the modified portions 57 are formed along the H element cut surface 111 of the substrate 103. .

  As shown in FIG. 13A, in the TFT array mother substrate 102, an electrode terminal 88 and a wiring 90b are formed near the H element cut surface 111. As shown in FIG. When the laser beam 56 is irradiated along the H element cut surface 111, the laser beam 56 passing through the TFT array mother substrate 102 may irradiate the electrode terminal 88 and the wiring 90b. Since the electrode terminal 88 and the wiring 90b are formed of a light-transmitting conductive film, the laser light 56 passes through the electrode terminal 88 and the wiring 90b. Therefore, the electrode terminal 88 and the wiring 90 b are not easily damaged by the laser beam 56.

  As a result, as shown in FIG. 15D, the modified portion 57 is formed in an array on all the H element cut surfaces 111 of the substrate 103, and a crack portion 58 is formed in the center of the modified portion 57. . Through the steps S13 to S16, the reforming portions 57 are arranged and formed along all the surfaces of the H facing cutting surface 109, the V facing cutting surface 110, the H element cutting surface 111, and the V element cutting surface 112. The

16A to 16D are diagrams corresponding to step S17. As shown in FIG. 16A, subsequently, the mother substrate 108 is placed on a base 60 made of an elastic material. The opposing mother substrate 106 of the mother substrate 108 is disposed so as to be in contact with the base 60, and the place facing the crack portion 58 formed on the V opposing cutting surface 110 in the TFT array mother substrate 102 is a pressing member. Press using 61. The counter mother substrate 106 sinks into the table 60, and tension acts on the crack portion 58. The counter mother substrate 106 breaks and splits starting from a crack portion 58 close to the surface in contact with the base 60.
As shown in FIG. 16B, as a result, the counter mother substrate 106 is divided at the V counter cut surface 110.

  Next, as shown in FIG. 16C, a place where the TFT array mother substrate 102 faces the crack portion 58 formed in an array on the H-opposing cut surface 109 is pressed using the pressing member 61. To do. The counter mother substrate 106 sinks into the table 60, and tension acts on the crack portion 58. The opposing mother substrate 106 breaks and breaks starting from a crack portion 58 close to the surface in contact with the table 60.

  As shown in FIG. 16D, as a result, the counter mother substrate 106 is divided by the H counter cut surface 109 and divided into several counter substrate pieces 107a.

Next, as shown in FIG. 17A, the TFT array mother substrate 102 of the mother substrate 108 is disposed so as to be in contact with the base 60. In the counter mother substrate 106, a location facing the crack portion 58 formed in an array on the V element cutting surface 112 is pressed using the pressing member 61. The TFT array mother substrate 102 sinks into the base 60, and tension acts on the crack portion 58. The TFT array mother substrate 102 breaks and breaks starting from a crack portion 58 close to the surface in contact with the base 60.
As a result, as shown in FIG. 17B, the TFT array mother substrate 102 is divided at the V element cut surface 112.

  Next, as shown in FIG. 17C, the opposing mother substrate 106 is pressed using the pressing member 61 at a location facing the crack portion 58 formed in an array on the H element cut surface 111. . The TFT array mother substrate 102 sinks into the base 60, and tension acts on the crack portion 58. The TFT array mother substrate 102 breaks and breaks starting from a crack portion 58 close to the surface in contact with the base 60.

  As shown in FIG. 17D, as a result, the TFT array mother substrate 102 is divided at the H element cut surface 111 and divided into several TFT array substrate pieces 103b. Through the above steps, the mother substrate 108 is divided and formed into the shape of the liquid crystal display device 81 shown in FIG. 8, and the polarizing sheets 98 and 99 shown in FIG. 9 are bonded to complete the liquid crystal display device 81.

As described above, this embodiment has the following effects.
(1) According to the present embodiment, in the TFT array mother substrate 102 constituting the liquid crystal display device 81, the electrode terminal 88 and the wiring 90 a are located in the vicinity of the place facing the H facing cutting surface 109 and the V facing cutting surface 110. , 90b are formed. The electrode terminal 88 and the wirings 90a and 90b are formed of a light transmissive conductive film.

  When the counter mother substrate 106 is divided, when the laser beam 56 used for forming the modified portion 57 is irradiated, the electrode terminals 88 and the wirings 90a and 90b formed on the TFT array mother substrate 102 are light transmissive. Therefore, it is hard to be damaged. Therefore, when the opposing mother substrate 106 is divided, a method of manufacturing the liquid crystal display device 81 that can prevent the electrode terminals 88 and the wirings 90a and 90b formed on the TFT array mother substrate 102 from being damaged can be obtained.

  (2) According to the present embodiment, in the TFT array mother substrate 102 constituting the liquid crystal display device 81, the electrode terminal 88 and the wirings 90 a and 90 b are formed near the H element cutting surface 111 and the V element cutting surface 112. Has been. The electrode terminal 88 and the wirings 90a and 90b are formed of a light transmissive conductive film.

  When the TFT array mother substrate 102 is divided, when the laser beam 56 used for forming the modified portion 57 is irradiated, the electrode terminals 88 and the wirings 90a and 90b formed on the TFT array mother substrate 102 are light transmissive. It is less susceptible to damage due to its nature. Therefore, when the TFT array mother substrate 102 is divided, a method for manufacturing the liquid crystal display device 81 that can prevent the electrode terminals 88 and the wirings 90a and 90b formed on the TFT array mother substrate 102 from being damaged can be obtained.

(3) According to this embodiment, the liquid crystal display device 81 has a switching element (TFT). The switching element controls the current flowing through the pixel electrode 96 by switching the current flow based on the electrical signal. Since the number of wirings can be reduced as compared with the method of forming wirings for supplying current to each pixel electrode 96, the liquid crystal display device 81 can be easily designed.
(Fourth embodiment)

Next, an electronic apparatus including the liquid crystal display device 81 according to the third embodiment will be described.
FIG. 18 is a schematic perspective view showing an example in which a liquid crystal display device is mounted on a personal computer. As shown in FIG. 18, the main body of a personal computer 120 as an electronic apparatus includes a display device 121 in a display unit that displays information. The display device 121 is provided with the liquid crystal display device 81 manufactured according to the third embodiment. The display device 121 disposed in the personal computer 120 is manufactured according to the above-described third embodiment, and the substrate in the display device 121 is scribed with the elements disposed on the substrate being hardly damaged by the laser beam. Is divided. Therefore, the personal computer 120 is an electronic device provided with a liquid crystal display device 81 in which the elements and the like arranged on the substrate are scribed and divided without being damaged by the laser light.

  In addition, this invention is not limited to the 1st-4th embodiment mentioned above, A various change and improvement can also be added. A modification will be described below.

(Modification 1)
In the first and second embodiments, two substrates of the first substrate 35, 71 and the second substrate 36, 65 are bonded, but three or more substrates are bonded. Can be carried out in the same manner. At that time, the same effect as in the first and second embodiments can be obtained.

(Modification 2)
In the first and second embodiments, the wiring and mounting terminals formed at locations near the second substrates 36 and 65 corresponding to the locations where the first substrates 35 and 71 are irradiated with the laser light 56, It is formed of a light transmissive conductive film. Wiring and mounting terminals are formed not only on the second substrates 36 and 65 but also on the first substrates 35 and 71, and wirings where the laser beam 56 may be irradiated among the wirings and mounting terminals. The mounting terminal may be formed of a light transmissive conductive film. At that time, the same effect as in the first and second embodiments can be obtained.

(Modification 3)
In the first embodiment, quartz glass is used for the first substrate 35 and the second substrate 36. In the second embodiment, quartz glass is used for the first substrate 71 and the second substrate 65. Used. In the third embodiment, quartz glass is used for the counter mother substrate 106 and the TFT array mother substrate 102. Any brittle material may be used as long as it is light transmissive and can form the liquid crystal display device 81. For example, in addition to quartz glass, soda-lime glass, borosilicate glass such as Pyrex (registered trademark), alkali-free glass such as OA-10 (manufactured by Nippon Electric Glass Co., Ltd.), and heat-resistant crystallized glass such as Neoceram (registered trademark) , Optical glass, crystal and the like.

(Modification 4)
In the third embodiment, the method for dividing a substrate 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 can prevent damage to wiring and mounting terminals by the laser light 56 in the step of dividing the substrate.

(Modification 5)
In the fourth embodiment, the liquid crystal display device 81 is used as the display device 121 of the personal computer 120. However, the present invention is not limited to this. For example, electronic book, mobile phone, digital still camera, LCD TV, viewfinder type or monitor direct-view type video tape recorder, car navigation device, pager, electronic notebook, calculator, word processor, workstation, video phone, POS terminal, touch panel It can be suitably used as an image display means of electronic equipment such as. In any case, it is possible to provide an electronic device having the liquid crystal display device 81 provided with the substrate that can prevent the wiring and the mounting terminal from being damaged by the laser light 56 in the step of dividing the substrate.

(Modification 6)
In the first to second 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 7)
In the third embodiment, in step S13 and step S14, after the opposing mother substrate 106 is scribed, the mother substrate 108 is inverted and the TFT array mother substrate 102 is scribed. After scribing the opposing mother substrate 106, the TFT substrate mother substrate 102 may be irradiated with laser light 56 from the mother substrate 108 side without inverting the mother substrate 108. Since the process of inverting the mother substrate 108 can be reduced, it can be manufactured with high productivity.

Schematic which shows the structure of the laser irradiation apparatus which concerns on 1st Embodiment. The flowchart of the dividing method of a board | substrate. (A)-(e) is a figure explaining the dividing method of a board | substrate. (A)-(d) is a figure explaining the dividing method of a board | substrate. (A)-(c) is a figure explaining the dividing method of the board | substrate which concerns on 2nd Embodiment. (A)-(c) is a figure explaining the dividing method of a board | substrate. (A) And (b) is a figure explaining the dividing method of a board | substrate. FIG. 6 is a schematic plan view of a liquid crystal display device according to a third embodiment. 1 is a schematic cross-sectional view of a liquid crystal display device. The flowchart of the manufacturing method of a liquid crystal display device. (A) And (b) is a schematic diagram which shows the TFT array mother board | substrate with which the liquid crystal display panel was dividedly formed. (A) And (b) is a figure explaining the manufacturing method of a liquid crystal display device. (A) And (b) is a schematic diagram which shows the mother board | substrate with which the liquid crystal display panel was dividedly formed. (A)-(d) is a figure explaining the manufacturing method of a liquid crystal display device. (A)-(d) is a figure explaining the manufacturing method of a liquid crystal display device. (A)-(d) is a figure explaining the manufacturing method of a liquid crystal display device. (A)-(d) is a figure explaining the manufacturing method of a liquid crystal display device. The schematic perspective view which shows the personal computer which concerns on 4th Embodiment.

Explanation of symbols

35, 72 ... first substrate, 36, 65 ... second substrate, 41, 46a, 46b, 46c, 46d, 46e, 49, 50, 54, 90a, 90b ... wiring as conductive films, 42a, 42b, 47, 48, 51, 52, 53, 66, 67, 68, 88 ... Electrode terminals as conductive films, 56 ... Laser light, 57 ... Modification part, 81 ... Liquid crystal display device as electro-optical device, 102 ... Substrate And a TFT array mother substrate as a second substrate, 106... A counter mother substrate as a first substrate, 120... A personal computer as an electronic device.

Claims (11)

A substrate dividing method for dividing a substrate,
A light-transmitting conductive film forming step of forming a light-transmitting conductive film through which laser light is transmitted on the substrate;
A metal conductive film forming step of forming a metal conductive film on the substrate;
A scribing step of irradiating the substrate with the laser light to form a modified portion inside the substrate;
A cutting step of pressing the modified portion to cut the substrate,
The substrate is a material that transmits the laser light,
The light transmissive conductive film is formed across a place where the laser light is irradiated in the scribing step,
The metal conductive film, wherein the laser beam in the scribing step is formed in a location that is not irradiated, and the metal conductive film is electrically in a position sandwiching the place where the laser beam of the light transmitting conductive film is illuminated Ru is connected,
A method for dividing a substrate, comprising: A substrate dividing method for joining a first substrate and a second substrate to divide the first substrate,
A light-transmitting conductive film forming step of forming a light-transmitting conductive film that transmits laser light on the second substrate;
Forming a metal conductive film on the second substrate;
A bonding step of bonding the first substrate and the second substrate;
A scribing step of irradiating the first substrate with the laser light to form a modified portion in the first substrate;
A cutting step of pressing the modified portion to cut the first substrate,
The substrate is a material that transmits the laser light,
The light transmissive conductive film is formed across a place where the laser light is irradiated in the scribing step,
The metal conductive film, wherein the laser beam in the scribing step is formed in a location that is not irradiated, and the metal conductive film is electrically in a position sandwiching the place where the laser beam of the light transmitting conductive film is illuminated Ru is connected,
A method for dividing a substrate, comprising: A method for dividing a substrate according to claim 1 or 2,
The method for dividing a substrate, wherein the light transmissive conductive film is an ITO film. A method for dividing a substrate according to claim 2 or 3,
In the scribing step, a modified portion is formed inside the first substrate by the laser beam, and the laser beam is transmitted through the first substrate to irradiate the second substrate, and the laser A method for dividing a substrate, wherein a modified portion is formed inside the second substrate by light. A method of manufacturing an electro-optical device, in which a first substrate that is light transmissive and a second substrate are joined to divide the first substrate,
5. A method for manufacturing an electro-optical device, wherein the method is formed using the substrate cutting method according to claim 2. A method for manufacturing the electro-optical device according to claim 5,
The method of manufacturing an electro-optical device, wherein the light transmissive conductive film is a wiring. A method for manufacturing the electro-optical device according to claim 5,
The method of manufacturing an electro-optical device, wherein the light transmissive conductive film is an electrode terminal. A method of manufacturing an electro-optical device according to any one of claims 5 to 7,
The electro-optical device includes a switching element, and the light-transmitting conductive film is electrically connected to the switching element. Claims 2-4
A substrate that is divided by the method for dividing a substrate according to any one of the above.   An electro-optical device manufactured using the method for manufacturing an electro-optical device according to claim 5.   An electronic apparatus comprising the electro-optical device according to claim 10 in a display unit.

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