JP2008018547A - Manufacturing method of substrate, manufacturing method of tft substrate, manufacturing method of multilayered structural substrate and manufacturing method of display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a substrate capable of enhancing the yield of the substrate by enhancing the impact resistance of the substrate at the time of handling of the substrate and suppressing the occurrence of the chipping of the corner part of the substrate. <P>SOLUTION: The manufacturing method of a substrate P as the substrate is constituted so as to irradiate the substrate P as the substrate with a laser beam 45 to form a divided piece Q1 and includes a process for forming a material deteriorated part 47 by obliquely irradiating the surface Pu of the substrate P with the laser beam 45 and a process for forming the divided piece Q1 by applying stress F to the substrate P. By this method, an inclined surface M is formed to the substrate P. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a substrate using laser light, a method for manufacturing a TFT substrate, a method for manufacturing a multilayer structure substrate, and a method for manufacturing a display device.

  Conventionally, when a substrate such as a semiconductor material substrate, a piezoelectric material substrate, or a glass substrate is cut, there is a method of cutting and dividing the substrate by irradiating the substrate with laser light.

  For example, as disclosed in Patent Document 1, in a method of cutting and dividing a substrate such as a semiconductor material substrate, a piezoelectric material substrate, or a glass substrate, laser light that is absorbed by the substrate is irradiated along the planned cutting line, There has been proposed a method in which a modified region portion by multiphoton absorption is formed from the front surface to the back surface of a substrate, and a divided piece is formed by cutting and dividing along the modified region portion.

JP 2002-192371 A

  However, in the method of Patent Document 1, chipping (chips) may occur in the corner portion of the substrate due to the impact force applied to the substrate when handling the substrate. In particular, semiconductor material substrates and glass substrates, etc., vary depending on the rigidity and thickness of the substrate, but chipping during handling tends to occur, and chipping tends to increase as the substrate thickness becomes thinner. there were. If chipping occurs in these semiconductor material substrates or glass substrates, depending on the size of the chipping, the substrate may become defective and cause a decrease in yield. It is not preferable in cutting and dividing.

  An object of the present invention is to provide a method of manufacturing a substrate capable of improving the yield by improving the impact resistance of the substrate when handling the substrate and suppressing the occurrence of chipping at the corner of the substrate. It is.

  The base body manufacturing method of the present invention is a base body manufacturing method in which a laser beam is irradiated onto a base to form divided pieces, and the surface of the base is irradiated obliquely with the laser light, and a material altered portion And forming a divided piece by applying stress to the base body, and forming an inclined surface on the base body.

  According to the present invention, since the laser beam is obliquely applied to the surface of the substrate, a material altered portion inclined obliquely with respect to the surface of the substrate can be formed. If the substrate is cut and divided along the surface, an inclined surface can be formed so as to connect the surface and the side surface of the substrate. If an inclined surface can be formed on the substrate, chipping that is likely to occur due to an impact during handling can be suppressed.

  In the substrate manufacturing method of the present invention, in the material altered portion forming step, the material altered portion is formed by irradiating the laser beam so as to pass through the surface of the substrate and the side surface of the substrate. desirable.

  According to the present invention, since the material altered portion can be formed obliquely by irradiating the laser beam so as to pass through the surface of the substrate and the side surface of the substrate, even if the substrate is thin, it is inclined to the substrate. Can be formed.

  In the method for manufacturing a substrate according to the present invention, in the material altered portion forming step, it is desirable to form the plurality of material altered portions by changing the irradiation angle of the laser beam and irradiating the laser beam a plurality of times.

  According to this invention, by changing the irradiation angle of the laser beam and irradiating the substrate with the laser beam a plurality of times, a plurality of material altered portions can be formed so as to pass through the surface and the side surface of the substrate. If the substrate is cut and divided along the plurality of material-affected portions formed, a polygonal surface can be formed on the substrate. If a polygonal surface can be formed on the substrate, chipping that is likely to occur due to an impact during handling can be further suppressed.

  In the substrate manufacturing method of the present invention, the substrate is made of a material that is transmissive to the laser beam. In the material altered portion forming step, the laser beam is collected on the substrate by a condensing element. It is desirable to form the material altered portion by irradiating with light.

  According to the present invention, since the laser beam is condensed by the condensing element and irradiated onto the substrate, the material altered portion can be formed at a predetermined position of the substrate.

  In the substrate manufacturing method of the present invention, in the material altered portion forming step, the laser beam is either a titanium sapphire laser or a YAG laser, and a fundamental wave of the titanium sapphire laser or the YAG laser is used. It is desirable to form the material altered portion by irradiation.

  According to this invention, when the fundamental wave of the titanium sapphire laser or YAG laser is irradiated to the substrate, the fundamental wave of the titanium sapphire laser or YAG laser has a wavelength that is transparent to the substrate. The material altered portion can be formed at a predetermined position of the substrate.

  The base body manufacturing method of the present invention is a base body manufacturing method in which a laser beam is irradiated onto a base body to form a segment, and the laser light is irradiated substantially vertically from the front surface to the back surface of the base body. A step of forming a first material altered portion, and a second material altered portion is formed by irradiating the laser beam obliquely to the surface of the base so as to be connected to the first material altered portion. And a step of applying a stress to the substrate to form a divided piece, wherein an inclined surface is formed on the divided piece.

  According to the present invention, the second material alteration portion can be formed obliquely so as to be connected to the first material alteration portion formed substantially at right angles to the surface of the base body. If the substrate is divided along the portion and the second material-modified portion, a divided piece having an inclined surface can be formed.

  In the substrate manufacturing method of the present invention, in the step of forming the divided pieces, it is desirable to form the divided pieces by applying either one of bending stress or tensile stress to the substrate.

  According to the present invention, since the base can be cut and divided only by applying stress to the base, the divided pieces can be easily formed.

  The TFT substrate manufacturing method of the present invention is characterized by being formed by the above-described substrate manufacturing method.

  According to this invention, since the TFT substrate is formed by the above-described substrate manufacturing method, a TFT substrate with less chipping can be manufactured.

  The method for producing a multilayer structure substrate of the present invention is characterized in that it is formed by the method for producing a substrate described above.

  According to the present invention, since the multilayer structure substrate is formed by the above-described substrate manufacturing method, a multilayer structure substrate with less chipping can be manufactured.

  The display device manufacturing method of the present invention is characterized by being formed by the above-described substrate manufacturing method.

  According to this invention, since the display device is formed by the above-described substrate manufacturing method, a display device with less chipping can be manufactured.

Hereinafter, embodiments of the method for producing a substrate of the present invention will be described in detail with reference to the accompanying drawings. Before describing the characteristic manufacturing method of the present invention, a substrate used in the present embodiment and a forming method for forming a material-modified portion in the substrate will be described.
<Substrate>

The substrate that can be used in this embodiment can be made of a material (mainly a ceramic material) such as glass, quartz, quartz, or silicon. Here, quartz is used as the substrate material.
<Formation method of material alteration part>

  A formation method for forming a material altered portion in the substrate by irradiating the substrate with laser light will be described.

  FIG. 1 is an explanatory diagram for explaining a method for forming a material-affected portion as a modified layer by laser light.

  In FIG. 1, the laser beam 45 is condensed and irradiated inside the substrate P, and the laser beam 45 is scanned in the scanning direction X (dividing direction). Since the laser beam 45 is condensed by the lens 46 as a condensing element, the laser beam 45 can be focused inside the substrate P. When the laser beam 45 is scanned in the scanning direction X (division direction), the material altered portion 47 as a modified layer can be formed inside the substrate P. The moving speed of the laser beam 45 in the scanning direction X is 100 mm / sec. The thickness of the substrate P is about 200 μm.

  Further, since the amount of the material altered portion 47 as the modified layer can be several tens of μm only by scanning the laser beam 45 once, in order to form the material altered portion 47 in the entire depth direction of the substrate P. Needs to scan the laser beam 45 several times in the scanning direction X (division direction). Each time the laser beam 45 is scanned, the focal position of the lens 46 as a condensing element is raised from the lower surface of the substrate P toward the upper surface. Here, the reason why the focal position of the laser beam 45 is raised from the lower surface to the upper surface of the substrate P is that the laser beam 45 is scattered by the material altered portion 47 formed earlier, and the entire region in the depth direction of the substrate P. This is to prevent the material altered portion 47 from being unable to be formed.

(First embodiment)
In this embodiment, laser beam is obliquely irradiated from the surface of the substrate toward the side surface to form a material altered portion inside the substrate, and stress is applied from the outside of the substrate to cut and divide the substrate to obtain divided pieces. A method for manufacturing the substrate to be manufactured will be described.

  FIG. 2 is a schematic diagram of the laser processing apparatus in the present embodiment, and FIG. 3 is a block diagram of a control system of the laser processing apparatus.

  The laser processing apparatus will be described with reference to FIGS.

  As shown in FIG. 2, the laser processing apparatus 100 includes a laser light source 101 that emits a laser beam 45 and a dichroic mirror 102 as a reflector that reflects the laser beam 45 emitted from the laser light source 101. . Further, the dichroic mirror 102 has a function of reflecting the amount of incident laser light 45. The dichroic mirror 102 is arranged so that the laser beam 45 can be applied to the surface of the substrate P as shown in FIG.

  The laser processing apparatus 100 includes a lens 46 as a condensing element that condenses the laser light 45 reflected by the dichroic mirror 102. And the lens 46 is arrange | positioned so that the laser beam 45 can be irradiated with respect to the surface of the board | substrate P, as shown to the same figure.

  In addition, a stage 107 on which a substrate P, which is a processing target, is placed, and an X-axis slide unit 110 and a Y-axis slide that move the stage 107 in the X-axis direction and the Y-axis direction with respect to the lens 46 as a condensing element. Part 108 is provided.

  The laser processing apparatus 100 has a function of tilting the substrate P by tilting the stage 107 at an arbitrary angle (not shown).

  Further, a Z-axis slide mechanism 104 that adjusts the position of the condensing point of the laser light 45 by changing the position of the lens 46 as a condensing element in the Z-axis direction with respect to the substrate P placed on the stage 107 is provided. Yes. The lens 46 as a condensing element is supported by a slide arm 104 a extending from the Z-axis slide mechanism 104. The lens 46 as a condensing element is an objective lens having a magnification of 50 times, a numerical aperture of 0.8, and a WD (Working Distance) of 3 mm.

  Further, the laser processing apparatus 100 includes an imaging device 112 positioned on the opposite side of the lens 46 as a light condensing element with the dichroic mirror 102 interposed therebetween. The imaging device 112 includes a coaxial incident light source (not shown) and a CCD (Charge Coupled Device) (not shown). The imaging device 112 can capture an image, and the captured image data is configured to be captured by the image processing unit 124. The visible light emitted from the coaxial incident light source (not shown) passes through the lens 46 as a condensing element and is focused.

Here, a laser beam 45 having transparency to the substrate P is employed. In the present embodiment, a YAG laser that excites a semiconductor laser is employed as the laser light emitted from the laser light source 101. The YAG laser is a so-called nanosecond laser that emits with a nanosecond pulse width. Detailed conditions of the laser beam 45 are as follows. The laser light source 101 excites a semiconductor laser. Laser medium: Nd: YAG. Laser wavelength: 1064 nm. Laser light spot cross section: 3.14 × 10 ⁻⁸ cm ² . Oscillation form: Q switch pulse. Repeat frequency: 100 KHz. Pulse width: 30 ns. Output: 20 μJ / pulse. Laser light quality: TEM ₀₀ . Polarization characteristics: linearly polarized light (C). Condenser lens magnification: 50 times. NA: 0.55. Transmittance with respect to laser light wavelength: 60% (D). Movement speed: 100 mm / sec.

  The laser wavelength of the YAG laser does not stick to 1064 nm, and for example, the second harmonic of the YAG laser may be used. The laser wavelength of the second harmonic is 532 nm. Further, the laser beam 45 may not be a YAG laser, and for example, an ultrashort pulse laser represented by a titanium sapphire laser may be adopted. If a titanium sapphire laser, which is an ultrashort pulse laser, is used, even if the beam diameter is somewhat increased due to the influence of aberrations, internal processing can be performed without any problem, and the material altered portion 47 (see FIG. 1) can be formed. . Detailed conditions of the laser beam 45 in this case are as follows. Laser wavelength: about 800 nm. Pulse width: about 300 fs (femtosecond). The pulse period is 1 kHz. Output: about 700 mW.

  The laser light source 101 that emits the laser beam 45 is controlled by the laser control unit 121 under predetermined conditions.

  As shown in FIG. 3, the laser processing apparatus 100 (see FIG. 2) includes a main computer 120 that can control each of the above components. The main computer 120 includes a CPU 127 (Central Processing Unit), a RAM 128 (Random Access Memory), and an image processing unit 124. The CPU 127 has a function capable of determining when a machining abnormality occurs. The RAM 128 has a function capable of storing the coordinate position of the scheduled cutting line.

  The main computer 120 is connected to an input unit 125 and a display unit 126. The input unit 125 can input data of various processing conditions used in laser processing. The display unit 126 can display various information at the time of laser processing.

  The laser control unit 121 is connected to the main computer 120 by a buffer 129 via the I / F 131, and can control the output of the laser light source 101, the pulse width, the pulse period, and the like.

  The lens control unit 122 is connected to the main computer 120 by a buffer 129 via the I / F 131. The lens control unit 122 has a built-in position sensor (not shown) that can detect the moving distance. Then, by detecting the output of this position sensor, the Z-axis slide mechanism 104 shown in FIG. 2 can be driven to control the position of the lens 46 as a condensing element in the Z-axis direction.

  The stage control unit 123 is connected to the main computer 120 by a buffer 129 via the I / F 131. The stage control unit 123 drives a servo motor (not shown) that moves the X-axis slide unit 110 and the Y-axis slide unit 108 shown in FIG. 2 along the rails 111 and 109 (see FIG. 2), respectively. Can do.

  The image processing unit 124 is connected to the imaging device 112 (see FIG. 2). The image processing unit 124 confirms the position in the Z-axis direction of the lens 46 as the light condensing element based on the image data of the image information acquired by the image pickup device 112, and the focus of the lens 46 as the light condensing element. Processing for adjusting the position can be performed. Further, the image processing unit 124 can confirm the position of the planned cutting line on the substrate P and can perform a process of adjusting the position.

  The laser processing apparatus 100 includes a main computer 120 as a control unit that can control the laser control unit 121, the lens control unit 122, the stage control unit 123, and the image processing unit 124.

  FIG. 4 is a diagram of a substrate in the present embodiment, FIG. 4A is a diagram illustrating a formation process in which a material-affected portion is formed by irradiating a laser beam, and FIG. 4B illustrates divided pieces. FIG. 4C is a diagram illustrating a formation process in which a material-affected portion is formed by irradiating a laser beam, and FIG. 4D is a schematic perspective view illustrating a divided state. FIG. 5 is a flowchart for explaining a manufacturing procedure for forming a divided piece by cutting and dividing a substrate in the present embodiment.

  With reference to FIG. 4 and FIG. 5, the manufacturing method of a base | substrate is demonstrated. More specifically, a description will be given of a method for manufacturing a substrate in which a material alteration portion is formed obliquely inside the substrate with respect to the surface of the substrate and the divided pieces are removed.

  In step S1 of FIG. 5, as shown in FIG. 4A, internal processing is performed (internal processing 1). In this internal processing, the laser beam 45 is condensed by a lens 46 as a condensing element and irradiated onto the substrate P to form a material altered portion 47 inside the substrate P. The laser beam 45 to be irradiated is irradiated while being inclined with respect to the surface Pu of the substrate P, and the irradiation angle θ is about 45 degrees. The laser beam 45 applied to the surface Pu of the substrate P is emitted to the side surface Ps of the substrate P. And the material alteration part 47 inclined about 45 degree | times can be formed. The laser beam 45 emitted here is a nanosecond laser employing a YAG laser.

  In step S2 of FIG. 5, as shown in FIG. 4B, division is performed (pressurization / division 1). In this dividing method, stress F is applied to the substrate P from the upper surface side of the substrate P. As a method of applying the stress F from the outside of the substrate P, for example, bending or shearing stress is applied to the substrate P along a planned cutting line in which the material altered portion 47 is formed. It is also possible to generate thermal stress by giving a temperature difference to the substrate P. When a stress F is applied from the outside to the substrate P having the material-affected portion 47, the substrate P is broken along the material-affected portion 47, and the divided pieces Q1 can be formed.

  In step S3 of FIG. 5, as shown in FIG. 4C, internal processing is performed (internal processing 2). In this internal processing, the substrate P is turned over, and the laser beam 45 is tilted and irradiated to the back surface Pd of the substrate P. The laser beam 45 applied to the back surface Pd of the substrate P is emitted to the side surface Ps of the substrate P. The internal machining method at this time is the same as step S1 in FIG.

  In step S4 of FIG. 5, as shown in FIG. 4D, division is performed (pressurization / division 2). And the board | substrate P is cracked along the material alteration part 47, and the division | segmentation piece Q1 can be formed. At the same time, a surface M can be formed on the substrate P, and this surface M is inclined by about 45 degrees. The division method here is the same as that in step S2 in FIG.

According to the manufacturing method of the first embodiment as described above, the following effects are obtained.
(1) Since the laser beam 45 is obliquely irradiated onto the surface Pu of the substrate P as a base body, the material altered portion 47 inclined obliquely with respect to the surface Pu of the substrate P can be formed. If the substrate P is cut and divided along the material altered portion 47, the inclined surface M can be formed so as to connect the surface Pu and the side surface Ps of the substrate P. If the inclined surface M can be formed on the substrate P, chipping that is likely to occur due to an impact during handling can be suppressed.
(2) Since the material altered portion 47 can be formed obliquely by irradiating the laser beam 45 so as to pass through the surface Pu and the side surface Ps of the substrate P, even if the substrate P becomes thin, An inclined surface M can be formed.
(3) Since the laser beam 45 is condensed by the lens 46 as a condensing element and irradiated onto the substrate P, the material altered portion 47 can be easily formed at a predetermined position on the substrate P.
(4) When the substrate P is irradiated with a fundamental wave of a titanium sapphire laser or YAG laser, the fundamental wave of the titanium sapphire laser or YAG laser has a wavelength that is transmissive to the substrate P. The material altered portion 47 can be easily formed at a predetermined position of the substrate P.
(5) Since the substrate P can be cut and divided simply by applying the stress F to the substrate P, the divided piece Q1 can be easily formed, and a new surface M can be formed obliquely on the substrate P. it can.

(Second Embodiment)
In this embodiment, laser light is irradiated obliquely multiple times from the surface of the substrate toward the side surface of the substrate to form a plurality of material altered portions inside the substrate, and the substrate is cut and divided by applying stress from the outside of the substrate. Then, the manufacturing method of the base | substrate which manufactures a division piece is demonstrated. The difference from the first embodiment described above is that a plurality of material altered portions are formed by changing the irradiation angle of the laser light a plurality of times. The laser processing apparatus used here is the same as that employed in the first embodiment. The same parts as those in the first embodiment described above and parts having the same functions are denoted by the same reference numerals and description thereof is omitted.

  FIG. 6 is a diagram of a substrate in the present embodiment, and FIGS. 6A to 6C are diagrams illustrating a formation process in which a plurality of material altered portions are formed by laser irradiation. ) Is a schematic perspective view showing a divided state. FIG. 7 is a flowchart for explaining a manufacturing procedure for cutting and dividing a substrate in this embodiment to form divided pieces.

  In step S11 of FIG. 7, as shown in FIG. 6A, internal processing is performed (internal processing 1). The laser beam 45 irradiated by this internal processing is irradiated with an inclination with respect to the surface Pu of the substrate P, and the irradiation angle θ1 is about 60 degrees. The laser beam 45 irradiated to the surface Pu is emitted to the side surface Ps of the substrate P. And the material alteration part 47a inclined about 60 degree | times with respect to the surface Pu is formed.

  In step S12 of FIG. 7, as shown in FIG. 6B, internal processing is performed (internal processing 2). The laser beam 45 irradiated by this internal processing is irradiated with an inclination with respect to the surface Pu of the substrate P, and the irradiation angle θ2 is about 45 degrees. The laser beam 45 irradiated to the surface Pu is emitted to the side surface Ps of the substrate P. And the material alteration part 47b inclined about 45 degree | times with respect to the surface Pu is formed. In addition, since the internal processing method at this time is the same as that of step S11 of FIG. 7, description is abbreviate | omitted.

  In step S13 of FIG. 7, as shown in FIG. 6C, internal processing is performed (internal processing 3). The laser beam 45 irradiated by this internal processing is irradiated with an inclination with respect to the surface Pu of the substrate P, and the irradiation angle θ3 is about 30 degrees. The laser beam 45 irradiated to the surface Pu is emitted to the side surface Ps of the substrate P. And the material alteration part 47c inclined about 30 degree | times with respect to the surface Pu is formed. In addition, since the internal processing method at this time is the same as that of step S11 of FIG. 7, description is abbreviate | omitted. Thus, a plurality of material altered portions 47a, 47b, 47c having an inclination can be formed.

  In step S14 of FIG. 7, division is performed as shown in FIG. In this dividing method, when the stress F is applied from the outside along the planned cutting line in which the material-affected portions 47a, 47b, 47c are formed, the substrate P is cracked and divided along the material-affected portions 47a, 47b, 47c. The piece Q1 can be formed. A polygonal surface M (M1, M2, M3) can be formed on the substrate P. Here, in this embodiment, the material altered portions 47a, 47b, 47c are formed at three locations, but this is not particular, and the irradiation angle of the laser beam 45 is set to various angles to irradiate the substrate P. More may be formed. In this way, it is possible to form the substrate P having more surfaces M (M1, M2, M3,... Mn) and to increase the surfaces M (M1, M2, M3,... Mn). If it can be formed, the occurrence of chipping can be further reduced. Further, since the laser processing apparatus 100 (see FIG. 2) has a function of controlling the irradiation angle θ of the laser light 45, a larger quantity of the material altered portions 47 (47a, 47b, 47c,... 47n ) Can also be formed. For example, the material-affected portions 47 (47a, 47b, 47c,... 47n) can be distributed in a semicircular shape (R shape). If the material altered portions 47 (47a, 47b, 47c,... 47n) can be distributed in a semicircular shape (R shape), the semicircular (R shape) surface M (M1, M2, M3,... A substrate P having Mn) can also be formed.

According to the manufacturing method of the second embodiment as described above, the following effects are obtained.
(6) By changing the irradiation angle of the laser beam 45 and irradiating the substrate P as the base with the laser beam 45 a plurality of times, a plurality of material altered portions 47 (passing through the surface Pu and the side surface Ps of the substrate P) 47a, 47b, 47c) can be formed. If the substrate P is cut / divided along the formed material altered portions 47 (47a, 47b, 47c), polygonal surfaces M (M1, M2, M3) can be formed on the substrate P. If a polygonal surface M (M1, M2, M3) can be formed on the substrate P, chipping that is likely to occur due to an impact during handling can be further suppressed.

(Third embodiment)
In this embodiment, a laser beam is irradiated from both a direction substantially perpendicular to the surface of the substrate and an oblique direction to form a material altered portion inside the substrate, and stress is applied from outside the substrate to apply the substrate to the substrate. A method for manufacturing the substrate to be cut and divided will be described. The difference from the first embodiment and the second embodiment described above is that a laser beam is irradiated to the entire thickness of the substrate to form a first material altered portion, and the laser beam is emitted a plurality of times from an oblique direction of the substrate. The second material altered portion was formed by irradiation. The laser processing apparatus used here is the same as that employed in the first embodiment. The same parts as those in the first embodiment and the second embodiment described above and parts having the same functions are denoted by the same reference numerals and description thereof is omitted.

  FIG. 8 is a diagram of a substrate in the present embodiment, and FIGS. 8A to 8C are diagrams illustrating a formation process in which a plurality of material altered portions are formed by irradiating a laser beam a plurality of times. (D) is a schematic perspective view which shows a division | segmentation state. FIG. 9 is a flowchart for explaining a manufacturing procedure for cutting and dividing the substrate in this embodiment to form divided pieces.

  In step S21 of FIG. 9, as shown in FIG. 8A, internal processing is performed (internal processing 1). The laser beam 45 irradiated by this internal processing is irradiated at a substantially right angle to the surface Pu of the substrate P, and the laser beam 45 irradiated to the surface Pu is emitted to the back surface Pd of the substrate P. Then, the first material altered portion 47a is formed in a direction substantially perpendicular to the surface Pu of the substrate P.

  In step S22 of FIG. 9, as shown in FIG. 8B, internal processing is performed (internal processing 2). The laser beam 45 radiated in this internal processing is radiated with an inclination with respect to the surface Pu of the substrate P, and the irradiation angle θ is about 45 degrees. The laser beam 45 irradiated to the front surface Pu is emitted to the back surface Pd of the substrate P. And the 2nd material alteration part 47b inclined about 45 degree | times is formed. As shown in the figure, the second material altered portion 47b is formed in two places. In addition, since the internal processing method at this time is the same as that of step S21 of FIG. 9, description is abbreviate | omitted.

  In step S23 of FIG. 9, as shown in FIG. 8C, internal processing is performed (internal processing 3). The substrate P is turned over, and the laser beam 45 is tilted and irradiated to the back surface Pd of the substrate P. The laser beam 45 applied to the back surface Pd of the substrate P is emitted to the front surface Pu of the substrate P. And the 2nd material alteration part 47b inclined about 45 degree | times is formed. The internal machining method at this time is the same as that in step S22 in FIG.

  In step S24 of FIG. 9, division is performed as shown in FIG. In this dividing method, stress F is applied to the substrate P from the upper surface side of the substrate P (see FIG. 8C). As a method of applying the stress F from the outside of the substrate P, for example, bending or applying shear stress to the substrate P along the planned cutting line in which the first material altered portion 47a and the second material altered portion 47b are formed. It is. It is also possible to generate thermal stress by giving a temperature difference to the substrate P. When a stress F is applied from the outside to the substrate P having the first material altered portion 47a and the second material altered portion 47b, the substrate P is moved along the first material altered portion 47a and the second material altered portion 47b. Can be divided to form divided pieces Q (two in this case) and divided pieces Q1 (two in this case). At the same time, the surface M can be formed on the divided piece Q.

According to the manufacturing method of the third embodiment as described above, the following effects are obtained.
(7) Since the second material altered portion 47b can be formed obliquely so as to be connected to the first material altered portion 47a formed substantially perpendicular to the surface Pu of the substrate P, the first material If the substrate P is divided along the altered portion 47a and the second material altered portion 47b, the divided piece Q having the inclined surface M can be formed. Since the divided piece Q has the surface M, chipping that is likely to occur due to impact force applied during handling can be suppressed.

(Fourth embodiment)
In this embodiment, a laser beam is irradiated from both a direction substantially perpendicular to the surface of the substrate and an oblique direction to form a material altered portion inside the substrate, and stress is applied from outside the substrate to apply the substrate to the substrate. A method for manufacturing the substrate to be cut and divided will be described. The difference from the first embodiment, the second embodiment, and the third embodiment described above is that the first material altered portion is formed by irradiating laser light halfway through the thickness of the substrate, and further the oblique direction of the substrate. Thus, the second material altered portion was formed by irradiating the laser beam multiple times. The laser processing apparatus used here is the same as that employed in the first embodiment. The same parts as those in the first to third embodiments and parts having the same functions are denoted by the same reference symbols, and description thereof is omitted.

  FIG. 10 is a diagram of a substrate in the present embodiment, and FIGS. 10A and 10B are diagrams illustrating a formation process in which a material-affected portion is formed by irradiating laser light, and FIG. It is a schematic perspective view which shows a division | segmentation state. FIG. 11 is a flowchart for explaining a manufacturing procedure for forming divided pieces by cutting and dividing a substrate in the present embodiment.

  In step S31 of FIG. 11, as shown in FIG. 10A, internal processing is performed (internal processing 1). The laser beam 45 irradiated by this internal processing is irradiated at a substantially right angle to the surface Pu of the substrate P, and the laser beam 45 irradiated to the surface Pu is emitted to the back surface Pd of the substrate P. Then, the first material altered portion 47a is formed in a substantially perpendicular direction. As shown in the figure, the formed first material altered portion 47a is up to the height H2, and the height H2 is lower than the thickness H1 of the substrate P. That is, the first material altered portion 47a is formed halfway through the thickness of the substrate P.

  In step S32 of FIG. 11, as shown in FIG. 10B, internal machining is performed (internal machining 2). The laser beam 45 radiated in this internal processing is radiated with an inclination with respect to the surface Pu of the substrate P, and the irradiation angle θ is about 45 degrees. The laser beam 45 irradiated to the front surface Pu is emitted to the back surface Pd of the substrate P. And the 2nd material alteration part 47b inclined about 45 degree | times with respect to the surface Pu is formed. As shown in the figure, the second material altered portion 47b is formed at two locations, and is formed so as to be connected to the first material altered portion 47a. In addition, since the internal processing method at this time is the same as that of step S31 of FIG. 11, description is abbreviate | omitted.

  In step S33 of FIG. 11, division is performed as shown in FIG. In this division method, stress F is applied to the substrate P from the upper surface side of the substrate P (see FIG. 10B). As a method of applying the stress F from the outside of the substrate P, for example, bending or applying shear stress to the substrate P along the planned cutting line in which the first material altered portion 47a and the second material altered portion 47b are formed. It is. It is also possible to generate thermal stress by giving a temperature difference to the substrate P. When a stress F is applied from the outside to the substrate P having the first material altered portion 47a and the second material altered portion 47b, the substrate P is moved along the first material altered portion 47a and the second material altered portion 47b. Can be divided to form divided pieces Q (two in this case) and divided pieces Q1 (one in this case). At the same time, a new surface M can be formed on the divided piece Q.

According to the manufacturing method of the fourth embodiment as described above, the following effects are obtained.
(8) Since the first material altered portion 47a can be suppressed to the minimum necessary height H2 in the thickness direction of the substrate P, the time required for forming the first material altered portion 47a is reduced. It can be efficient.

  Next, a liquid crystal panel as a display device according to the present invention will be described.

  FIG. 12 is a schematic view showing the structure of the liquid crystal panel in the present embodiment, FIG. 12 (a) is a schematic plan view, and FIG. 12 (b) is cut along the line AA in FIG. FIG.

  As shown in FIGS. 12A and 12B, the liquid crystal panel 10 includes a TFT substrate 1 having a TFT 3, a counter substrate 2 having a counter electrode 6, and a TFT substrate 1 bonded by a sealing material 4. And a liquid crystal 5 filled in a gap with the substrate 2.

As the TFT substrate 1, a quartz substrate having a thickness of about 1.2 mm is used, and the surface thereof is composed of a pixel electrode (not shown) constituting a pixel and a plurality of transistor elements (not shown). TFT3 is formed. One of the three terminals of the individual transistor elements constituting the TFT 3 is connected to the pixel electrode, and the other two are data lines (in the figure) arranged in a grid in a state of being insulated from each other surrounding the pixel electrode. And a scanning line (not shown). The data line and the scanning line are connected to the drive circuit unit 9 in the terminal unit 1a through the wiring pattern 11. The input side wiring pattern 12 of the drive circuit unit 9 is connected to the mounting terminals 13 arranged in the terminal unit 1a. The TFT substrate 1 has a surface M (material altered portion 47) formed according to this embodiment.

  The counter substrate 2 includes a counter substrate body 2a, a microlens 15, and a cover glass 16. A quartz substrate having a thickness of about 1.1 mm is used as the counter substrate main body 2a, and a microlens surface 2b is formed on a portion of the TFT substrate 1 facing the pixel electrode. The microlens 15 is formed by filling the microlens surface 2b of the counter substrate body 2a with a compatible resin. A quartz substrate having a thickness of about 50 μm is used for the cover glass 16, and is bonded to the counter substrate body 2 a with a compatible resin forming the microlens 15. The counter substrate 2 has a surface M (material altered portion 47) formed according to the present embodiment.

The microlens 15 functions to improve the aperture ratio of the liquid crystal panel 10 and has a one-to-one correspondence with the pixel electrode. The cover glass 16 protects the microlens 15 by covering the entire area of the counter substrate body 2a.

The counter substrate 2 is provided with a counter electrode 6 as a common electrode. The counter electrode 6 is electrically connected to a wiring pattern (not shown) provided on the TFT substrate 1 side through vertical conduction parts 14 provided at the four corners of the counter substrate 2, and the wiring pattern is also provided in the terminal part 1a. Connected to the mounting terminals 13. Alignment films 7 and 8 are respectively formed on the surface of the TFT substrate 1 facing the liquid crystal 5 and the surface of the counter substrate 2.

The liquid crystal panel 10 is a relay board (not shown) that is electrically connected to an external drive circuit (not shown).
Is connected to the mounting terminal 13. When an input signal from the external drive circuit is input to the drive circuit unit 9, the TFT 3 is switched for each pixel electrode, and a drive voltage is applied between the pixel electrode and the counter electrode 6 to perform display. .

  Since the TFT substrate 1 is manufactured by the cutting and dividing method of the present invention and has a new surface M, the TFT substrate 1 capable of suppressing chipping can be manufactured. Further, since the multilayer structure substrate 17 composed of the TFT substrate 1 and the counter substrate 2 is manufactured by the cutting / dividing method of the present invention and has a new surface M, chipping can be suppressed. Can be manufactured. Since the liquid crystal panel 10 as a display device includes the multilayer substrate 17 described above, the liquid crystal panel 10 as a display device capable of suppressing chipping can be provided.

  Next, a liquid crystal display device which is an example of the electro-optical device according to the invention will be described.

  FIG. 13 is an exploded perspective view of a liquid crystal display device as an electro-optical device.

  As shown in FIG. 13, the liquid crystal display device 500 includes a multilayer circuit board 30. The liquid crystal display device 500 includes a color display liquid crystal panel 10, a multilayer circuit board 30 connected to the liquid crystal panel 10, a liquid crystal driving IC 300 mounted on the multilayer circuit board 30, and the like. If necessary, an illumination device such as a backlight and other auxiliary devices are attached to the liquid crystal panel 10. The liquid crystal display device 500 has a COF (Chip / On / Film) structure.

  The liquid crystal panel 10 has a pair of TFT substrates 1 and a counter substrate 2 bonded by a sealing material 4, and liquid crystal is formed in a gap (cell gap) formed between the TFT substrate 1 and the counter substrate 2. 5 (see FIG. 12B) is sealed, and the sealed liquid crystal 5 (see FIG. 12B) is sandwiched between the TFT substrate 1 and the counter substrate 2. The TFT substrate 1 and the counter substrate 2 are generally formed of a translucent material such as quartz, glass, synthetic resin or the like. A polarizing plate 56 is attached to the outer surfaces of the TFT substrate 1 and the counter substrate 2.

  Further, the pixel electrode 66 is formed on the inner surface of the TFT substrate 1, and the counter electrode 6 is formed on the inner surface of the counter substrate 2. The pixel electrode 66 and the counter electrode 6 are formed of a light-transmitting material such as ITO ((Indium / Tin / Oxide): indium tin oxide). The TFT substrate 1 has a projecting portion that projects from the counter substrate 2, and a plurality of mounting terminals 13 are formed on the projecting portion. These mounting terminals 13 are formed simultaneously with the pixel electrode 66 when the pixel electrode 66 is formed on the TFT substrate 1. Accordingly, these mounting terminals 13 are made of, for example, ITO. These mounting terminals 13 include one that extends integrally from the pixel electrode 66 and one that is connected to the counter electrode 6 via a conductive material (not shown).

  On the other hand, wiring patterns 39 a and 39 b are formed on the surface of the multilayer circuit board 30. That is, an input wiring pattern 39a is formed from one short side to the center of the multilayer circuit board 30, and an output wiring pattern 39b is formed from the other short side to the center. Electrode pads (not shown) are formed at the ends of the input wiring pattern 39a and the output wiring pattern 39b on the center side.

  A liquid crystal driving IC 300 is mounted on the surface of the multilayer circuit board 30. Specifically, with respect to a plurality of electrode pads (not shown) formed on the surface of the multilayer circuit board 30, a plurality of bump electrodes formed on the active surface of the liquid crystal driving IC 300 are formed by an ACF (Anisotropic Conductive • (Film: anisotropic conductive film) 160 is connected. The ACF 160 is formed by dispersing a large number of conductive particles in a thermoplastic or thermosetting adhesive resin. Thus, by mounting the liquid crystal driving IC 300 on the surface of the multilayer circuit board 30, a so-called COF structure is realized.

  A multilayer circuit board 30 including a liquid crystal driving IC 300 is connected to the TFT substrate 1 of the liquid crystal panel 10. Specifically, the output wiring pattern 39 b of the multilayer circuit board 30 is electrically connected to the mounting terminal 13 of the TFT substrate 1 via the ACF 140. Since the multilayer circuit board 30 has flexibility, space saving can be realized by freely folding it.

  In the liquid crystal display device 500 configured as described above, a signal is input to the liquid crystal driving IC 300 via the input wiring pattern 39 a of the multilayer circuit board 30. Then, a driving signal is output from the liquid crystal driving IC 300 to the liquid crystal panel 10 via the output wiring pattern 39 b of the multilayer circuit board 30. As a result, an image is displayed on the liquid crystal panel 10.

  Since the liquid crystal display device 500 includes the liquid crystal panel 10 as a display device capable of suppressing chipping, the yield can be improved and the liquid crystal display device 500 as an electro-optical device with lower cost can be obtained. Can be provided.

  Next, an electronic apparatus equipped with a liquid crystal display device as an electro-optical device according to the invention will be described.

  FIG. 14 is a perspective view of a mobile phone as an electronic device.

  As shown in FIG. 14, a mobile phone 2000 as an electronic apparatus according to the present embodiment includes the above-described liquid crystal display device 500 as a display unit. The mobile phone 2000 includes a display unit 2001. As described above, since the mobile phone 2000 as an electronic apparatus according to the present invention can include the liquid crystal display device 500 as an electro-optical device with good production efficiency, the mobile phone 2000 as an electronic apparatus with good production efficiency. Can be provided. Also, the electronic device is not particular about the mobile phone 2000. For example, a portable information device called a printer, a wristwatch, a NOTE-PC, a PDA, an electronic paper, a portable terminal device, a personal computer, a word processor, a digital still camera, It can be suitably used as an image display means for a vehicle-mounted monitor, a monitor direct-view digital video recorder, a car navigation device, an electronic notebook, a workstation, a video phone, a POS terminal, and the like. By doing so, the use of the liquid crystal display device 500 as an electro-optical device is expanded, and various electronic devices can be provided.

  The present invention has been described above with reference to preferred embodiments. However, the present invention is not limited to the above-described embodiments, and includes modifications as described below, as long as the object of the present invention can be achieved. It can be set to any other specific structure and shape.

(Modification)
In the first embodiment described above, the irradiation angle θ of the laser beam 45 to be irradiated is set to about 45 degrees and the surface Pu of the substrate P is irradiated. However, the present invention is not limited to this. For example, the irradiation angle θ may be set smaller than about 45 degrees or larger. Even in this way, the surface M can be formed at the corners of the substrate P (in this case, the corners of the front surface Pu and the side surface Ps and the corners of the back surface Pd and the side surface Ps), so the first embodiment. The same effect can be obtained.

Explanatory drawing for demonstrating the formation method of the material alteration part as a modified layer by a laser beam. Schematic of the laser processing apparatus in 1st Embodiment. The block diagram of the control system of a laser processing apparatus. FIG. 4A is a view of a substrate, FIG. 1A is a view showing a formation process in which a material altered portion is formed by irradiating a laser beam, FIG. 2B is a view showing divided pieces, and FIG. These are figures which show the formation process which irradiates a laser beam, and forms a material alteration part, FIG. (D) is a schematic perspective view which shows a division | segmentation state. The flowchart for demonstrating the manufacturing procedure which cut | disconnects and divides | segments a board | substrate and forms a division | segmentation piece. It is a figure of the board | substrate in 2nd Embodiment, A figure (a)-a figure (c) are figures which show the formation process which irradiates a laser beam and forms a some material alteration part, and figure (d) is a figure. The schematic perspective view which shows a division | segmentation state. The flowchart for demonstrating the manufacturing procedure which cut | disconnects and divides | segments a board | substrate and forms a division | segmentation piece. It is a figure of the board | substrate in 3rd Embodiment, A figure (a)-a figure (c) are figures which show the formation process which irradiates a laser beam and forms a some material alteration part, and figure (d) is a figure. The schematic perspective view which shows a division | segmentation state. The flowchart for demonstrating the manufacturing procedure which cut | disconnects and divides | segments a board | substrate and forms a division | segmentation piece. It is a figure of the board | substrate in 4th Embodiment, FIG. (A), FIG. (B) is a figure which shows the formation process which irradiates a laser beam and forms a material alteration part, FIG. (C) is a division | segmentation state FIG. The flowchart for demonstrating the manufacturing procedure which cut | disconnects and divides | segments a board | substrate and forms a division | segmentation piece. It is the schematic which shows the structure of the liquid crystal panel as a display apparatus, A figure (a) is a schematic plan view, A figure (b) is a schematic sectional drawing cut | disconnected along the AA line of Fig. (A) . 1 is an exploded perspective view of a liquid crystal display device as an electro-optical device. The perspective view of the mobile telephone as an electronic device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... TFT substrate, 10 ... Liquid crystal panel as a display device, 17 ... Multi-layered structure substrate, 45 ... Laser light, 46 ... Lens as a condensing element, 47 ... Material alteration part as a modified layer, 47a ... 1st Material alteration section, 47b ... second material alteration section, 100 ... laser processing apparatus, 101 ... laser light source, 102 ... dichroic mirror as a reflector, 107 ... stage, 112 ... imaging apparatus, 120 ... main computer as control section , 121 ... laser control unit, 122 ... lens control unit, 123 ... stage control unit, 500 ... liquid crystal display device as an electro-optical device, 2000 ... mobile phone as electronic equipment, F ... stress, H1 ... substrate thickness, H2 ... height of the first material alteration part, M (M1, M2, M3) ... surface, P ... substrate as substrate, Pu ... front surface, Pd ... back surface, Ps ... side surface, Q (Q1) Divided pieces, θ (θ1, θ2, θ3) ... irradiation angle.

Claims (10)

A method of manufacturing a substrate by irradiating the substrate with laser light to form divided pieces,
A material altered portion forming step of obliquely irradiating the surface of the substrate with the laser beam to form a material altered portion;
Applying stress to the base body to form divided pieces,
A method of manufacturing a substrate, comprising forming an inclined surface on the substrate. In the manufacturing method of the base according to claim 1,
In the material altered portion forming step,
A method of manufacturing a substrate, comprising forming the material altered portion by irradiating the laser beam obliquely so as to pass through a surface of the substrate and a side surface of the substrate. In the manufacturing method of the base according to claim 1 or 2, In the material alteration part formation process,
A method of manufacturing a substrate, wherein the laser beam is irradiated a plurality of times while changing the irradiation angle of the laser beam to form a plurality of the material altered portions. In the manufacturing method of the base according to any one of claims 1 to 3,
The base is made of a material having transparency to the laser beam;
In the material altered portion forming step,
A method of manufacturing a substrate, wherein the material-affected portion is formed by condensing and irradiating the substrate with the laser beam by a condensing element. In the manufacturing method of the base according to any one of claims 1 to 4,
In the material altered portion forming step,
The laser beam is either a titanium sapphire laser or a YAG laser,
A substrate manufacturing method, wherein the material altered portion is formed by irradiating a fundamental wave of the titanium sapphire laser or the YAG laser. A method of manufacturing a substrate by irradiating the substrate with laser light to form divided pieces,
Irradiating the laser beam substantially perpendicularly from the front surface to the back surface of the substrate to form a first material altered portion;
Irradiating the laser beam obliquely with respect to the surface of the base so as to be connected to the first material altered portion, and forming a second material altered portion;
Applying stress to the substrate to form a divided piece,
A method of manufacturing a substrate, comprising forming an inclined surface on the divided piece. In the manufacturing method of the base according to any one of claims 1 to 6,
In the step of forming the divided pieces,
A method of manufacturing a substrate, comprising applying the stress to one of bending stress or tensile stress to the substrate to form the divided pieces.   A method for manufacturing a TFT substrate, wherein the TFT substrate is formed by the method for manufacturing a substrate according to any one of claims 1 to 7.   It is formed with the manufacturing method of the base | substrate as described in any one of Claims 1-7, The manufacturing method of the multilayer structure board | substrate characterized by the above-mentioned. A method for manufacturing a display device, characterized in that the display device is formed by the method for manufacturing a substrate according to any one of claims 1 to 7.

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