JP2017039619A - Scribe line checking method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discriminate whether or not a crack line has been properly formed.SOLUTION: The first face SF1 of a brittle substrate 4 is formed thereon with a scribe line SL having a trench line TL extending in an extending direction at one position over a first face SF1. An incident light L1 by a laser is irradiated just below one position of the first face SF1 of the fragile substrate 4 from the outside of the fragile substrate 4 through the first face SF1. The optical axis direction of the incident light L1 has an inclination component in a direction perpendicular to the extending direction on the first face SF1 with respect to a direction vertical to the first face SF1. A crack line CL reflects the incident light LI thereby to establish a reflection light LR toward a second face SF2. By reflecting the reflection light LR, there is established an ejection light LO from a second face SF2 through the first face SF1 toward the outside of the fragile substrate 4 via the first surface SF1. The intensity of the ejection light LO is measured.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a method for inspecting a scribe line formed on a brittle substrate.

  In the manufacture of electrical equipment such as flat display panels or solar cell panels, it is often necessary to break a brittle substrate such as a glass substrate. First, a scribe line is formed on the substrate, and then the substrate is divided along the scribe line. The scribe line can be formed by mechanically processing the substrate using a cutting tool. When the cutting tool slides or rolls on the substrate, a trench due to plastic deformation is formed on the substrate, and at the same time, a vertical crack is formed immediately below the trench. Thereafter, stress is applied, which is called a breaking process. The substrate is divided by causing the crack to proceed completely in the thickness direction by the breaking process.

  The step of dividing the substrate is often performed immediately after the step of forming a scribe line on the substrate. However, it has also been proposed to perform a step of processing the substrate between the step of forming the scribe line and the breaking step. The process of processing a board | substrate is a process of providing a certain member on a board | substrate, for example.

  For example, according to the technique of International Publication No. 2002/104078, in the method of manufacturing an organic EL display, a scribe line is formed on a glass substrate for each region to be each organic EL display before mounting a sealing cap. For this reason, the contact with a sealing cap and a glass cutter which may be a problem when a scribe line is formed on a glass substrate after providing a sealing cap can be avoided.

  For example, according to the technique of International Publication No. 2003/006391, in a method for manufacturing a liquid crystal display panel, two glass substrates are bonded together after a scribe line is formed. As a result, two brittle substrates can be simultaneously broken in a single breaking step.

International Publication No. 2002/104078 International Publication No. 2003/006391

  According to the above-described conventional technique, the brittle substrate is processed after the scribe line is formed, and then the breaking process is performed by applying stress. This means that vertical cracks already exist when processing into brittle substrates. If further extension in the thickness direction of the vertical crack occurs unintentionally during the processing, the brittle substrate that should be united may be separated during the processing. Also, even when the substrate processing step is not performed between the scribe line forming step and the substrate breaking step, the substrate is usually transported or stored after the scribe line forming step and before the substrate breaking step. In this case, the substrate may be unintentionally divided.

  In order to solve the above-mentioned problems, the present inventor has developed a unique cutting technique. According to this technique, as a line that defines a position where a brittle substrate is divided, first, a trench line having no crack is formed immediately below the line. The formation of the trench line defines the position where the brittle substrate will be divided. Thereafter, if a state in which no crack exists immediately below the trench line (hereinafter also referred to as a “crackless state”) is maintained, division along the trench line is difficult to occur. By using this state, it is possible to prevent the brittle substrate from being unintentionally divided before the time point at which it should be divided, while predefining the position where the brittle substrate is to be divided. However, when a crack line is formed after the crackless state is maintained, a crack line formation defect is relatively likely to occur. Therefore, a method for easily discriminating the presence or absence of crack line formation failure has been demanded.

  Further, even when a scribe line is formed by a normal method without a crackless state, a method for easily determining the presence or absence of crack line formation may be required. For example, when the scribe line is formed by rolling of a cutting tool, the perpendicularity of the extension in the depth direction of the crack line is likely to be disturbed. As a result, there may be a problem in the breaking process along the crack line.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a scribe line inspection method that can determine whether or not a crack line is appropriately formed. It is.

  A scribe line inspection method of the present invention is a scribe line inspection method including a trench line and a crack line extending along the trench line immediately below the trench line, and includes the following steps. A brittle substrate having a first surface and a second surface opposite to the first surface is prepared. A scribe line having a trench line extending in the extending direction at one position on the first surface is provided on the first surface. Incident light from a laser is irradiated from the outside of the brittle substrate to a position immediately below one position of the first surface of the brittle substrate via the first surface. The optical axis direction of the incident light has an inclination component in the direction perpendicular to the extending direction on the first surface with reference to the direction perpendicular to the first surface. When the crack line reflects incident light, reflected light directed to the second surface is generated. By reflecting the reflected light, outgoing light is generated from the second surface to the outside of the brittle substrate via the first surface. The intensity of the emitted light is measured.

  According to the present invention, the intensity of the emitted light depends on whether or not the crack line is appropriately formed. Therefore, it is possible to determine whether or not the crack line is properly formed by measuring the intensity of the emitted light.

It is a flowchart which shows schematically the structure of the inspection method of the scribe line in Embodiment 1 of this invention. It is a top view which shows roughly 1 process of the inspection method of the scribe line in Embodiment 1 of this invention. It is a fragmentary end view which shows roughly the structure of the scribe line which has a normal crack line. It is a fragmentary end view which shows roughly the structure of the scribe line which has the crack line in which the perpendicularity was disturb | confused. It is a fragmentary end view which shows roughly the structure of the scribe line which lacks a crack line. It is sectional drawing which shows schematically the structure of the inspection apparatus used for the inspection method of the scribe line in Embodiment 1 of this invention. It is sectional drawing which shows roughly 1 process of the inspection method of the scribe line in Embodiment 1 of this invention. FIG. 8 is a top view schematically showing the step of FIG. 7. It is sectional drawing which shows roughly 1 process of the inspection method of the scribe line in Embodiment 1 of this invention. FIG. 10 is a top view schematically showing the step of FIG. 9. It is a fragmentary sectional view which shows schematically advancing of light when the inspection method of the scribe line in Embodiment 1 of this invention is performed with respect to a normal scribe line. It is a fragmentary sectional view which shows roughly advancing of light when the inspection method of the scribe line in Embodiment 1 of this invention is performed with respect to the scribe line which has the crack line in which the perpendicularity was disturb | confused. It is a fragmentary sectional view which shows roughly advancing of light when the inspection method of the scribe line in Embodiment 1 of this invention is performed with respect to the scribe line which lacks a crack line. It is a flowchart which shows schematically the structure of the formation method of the scribe line in Embodiment 2 of this invention. It is a side view which shows roughly the structure of the instrument used for the cutting method of the brittle board | substrate in Embodiment 2 of this invention. It is a schematic plan view in the viewpoint of the arrow XVI of FIG. It is a top view which shows roughly the formation process of the trench line in Embodiment 2 of this invention. It is a top view which shows roughly the formation process of the crack line in Embodiment 2 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
In the present embodiment, a case where a scribe line is formed by a normal method not involving a crackless state will be described.

  FIG. 1 is a flowchart schematically showing a configuration of a scribe line inspection method in the present embodiment. Hereinafter, a scribe line inspection method will be described with reference to FIG.

  2 and 3, first, a glass substrate 4 (brittle substrate) having a flat upper surface SF1 (first surface) and a flat lower surface SF2 (second surface opposite to the first surface). ) Is prepared (FIG. 1: Step S10). A scribe line SL is provided on the upper surface SF1.

  The scribe line SL has a trench line TL and a crack line CL extending along the trench line TL immediately below the trench line TL. The trench line TL extends in the extending direction (lateral direction in FIG. 2). The trench line TL is typically linear, but a curved trench line may be formed. In this case, the trench line extends in one extending direction at at least one position on the upper surface SF1. It is extended. The crack line CL is a crack extending from the recess of the trench line TL into the glass substrate 4 in the thickness direction DT perpendicular to the upper surface SF1.

  The continuous connection is broken in the direction DC (FIG. 3) where the glass substrate 4 intersects the extending direction of the trench line TL immediately below the trench line TL by the crack line CL. Here, “continuous connection” means a connection that is not interrupted by a crack. In addition, in the state where the continuous connection is cut as described above, the portions of the glass substrate 4 may be in contact with each other through the cracks of the crack line CL.

  In the present embodiment, scribe line SL can be formed by a normal scribe method. Specifically, when a cutting tool such as a diamond cutter slides or rolls on the upper surface SF1 of the glass substrate 4, a trench due to plastic deformation is formed on the glass substrate 4, and at the same time immediately below this trench. Vertical cracks are formed.

  In some cases, the scribe line SL (FIG. 3) having the normal crack line CL may not be formed on the upper surface SF1 due to some factor. Specifically, as shown in FIG. 4, a scribe line SA having a crack line CA whose verticality is disturbed (curved or inclined) may be formed. Alternatively, as shown in FIG. 5, the scribe line may lack the crack line CL (FIG. 3). Therefore, an inspection is performed to determine whether the scribe line SL is properly formed.

  Referring to FIG. 6, an inspection apparatus 40 is prepared for the purpose of the inspection. The inspection device 40 includes a reflecting member 10, a substrate holder 11, a table 12, a laser head 20, a head position adjustment unit 28, and an amplifier 29. The laser head 20 has a light source 21 and a sensor 22.

  The table 12 supports the glass substrate 4 via the reflecting member 10. The table 12 is for displacing the glass substrate 4. For example, as shown by arrows A1 and A2 in the figure, the table 12 adjusts the horizontal position and the inclination angle of the glass substrate 4. The substrate holder 11 presses the glass substrate 4 onto the table 12. By being pressed by the substrate presser 11, the deflection of the glass substrate 4 can be corrected. Thereby, the glass substrate 4 and the reflecting member 10 are more closely adhered to each other. Therefore, it becomes difficult to form a gap between them.

  The light source 21 emits light from a laser as incident light LI to the glass substrate 4 to be inspected. The wavelength of the laser is selected so that the incident light LI can easily pass through the glass substrate 4. When the inspection target is the glass substrate 4 as in the present embodiment, for example, a wavelength in the visible light region can be used. The sensor 22 detects the emitted light LO from the glass substrate 4. The signal detected by the sensor 22 is processed by the amplifier 29, whereby the intensity of the emitted light LO is measured. The head position adjusting unit 28 is for displacing the laser head 20 and, for example, adjusts the height position parallel to the thickness direction of the glass substrate 4 as indicated by an arrow A3 in the drawing. When the laser head 20 is displaced, the light source 21 and the sensor 22 included in the laser head 20 are moved together.

  The reflecting member 10 has a surface that can efficiently reflect the laser light from the light source 21. For this reason, it is preferable that the surface of the reflecting member 10 has a flat shape and a high reflectance in the wavelength region of the laser light. When laser light in the visible light region is used, for example, a silicon wafer having a polished surface can be used as the reflecting member 10.

  7 and 9 are cross-sectional views showing a state of inspection using the inspection apparatus 40 (FIG. 6). 8 and 10 are top views schematically showing the steps of FIGS. 7 and 9 respectively. 8 and 10 illustrate five scribe lines SL, but only one of them is shown in FIGS. 7 and 9 for simplification.

  Referring to FIG. 7, first, lower surface SF <b> 2 of glass substrate 4 is placed on reflecting member 10. Next, the glass substrate 4 is pressed against the table 12 via the reflecting member 10 by the substrate presser 11. Incident light LI to the glass substrate 4 is emitted from the light source 21. Thereby, the spot light SP (FIGS. 7 and 8) of the incident light LI is locally applied onto the upper surface SF1 of the glass substrate 4. The optical axis direction of the incident light LI is perpendicular to the extending direction of the trench line TL (the direction perpendicular to the paper surface in FIG. 7) on the upper surface SF1, with reference to the direction perpendicular to the upper surface SF1 (the vertical direction in FIG. 7). It has an inclination component in the direction (lateral direction in FIG. 7). Preferably, the optical axis direction of the incident light LI is the direction in which the trench line TL extends on the upper surface SF1 (the direction perpendicular to the paper surface in FIG. 7) on the basis of the direction perpendicular to the upper surface SF1 (vertical direction in FIG. 7). It inclines toward the direction perpendicular | vertical (lateral direction in FIG. 7).

  The upper surface SF1 is scanned with the spot light SP of the incident light LI along the direction intersecting the trench line TL (the horizontal direction in FIG. 9 and the scanning direction SC in FIG. 10). As a result, the incident light LI is irradiated from the outside of the glass substrate 4 directly below the one position of the upper surface SF1 where the trench line TL extends in the extending direction via the upper surface SF1 (FIG. 1: Step S20). The phenomenon caused by this will be described below in three cases.

  Referring to FIG. 11, first, when a normal crack line CL that is substantially perpendicular to the upper surface SF1 is formed, the crack line CL reflects the incident light LI, so that the reflected light LR toward the lower surface SF2 is reflected. Occurs. A part of the incident light LI may pass through the crack line CL as the transmitted light LT. When the reflecting member 10 disposed on the lower surface SF2 reflects the reflected light LR, outgoing light LO is generated from the lower surface SF2 to the outside of the glass substrate 4 via the upper surface SF1 (FIG. 1: step S30). . By detecting the emitted light LO by the sensor 22 (FIG. 9), the intensity of the emitted light LO is measured (FIG. 1: step S40). This strength is sufficiently high due to the presence of the crack line CL.

  Referring to FIG. 12, secondly, when crack line CA having a disordered (curved) verticality is formed, crack line CA diffuses incident light LI, so that it is sufficiently high as in FIG. The reflected light LR is not obtained. As a result, the intensity of the emitted light LO to be measured is smaller than when the crack line CL (FIG. 11) is formed. Similarly, when the inclined crack line is formed, reflected light having a different reflection angle is generated as compared with the case where the normal crack line CL is formed. In this case, the emitted light is not received by the sensor 22 set to receive the reflected light of the normal crack line CL, and the crack line CL (FIG. 11) is formed as the intensity of the emitted light LO to be measured. It becomes smaller than the case.

  Referring to FIG. 13, thirdly, when the crack line CL is missing directly below the trench line TL, the reflected light LR (FIG. 11) is not generated. As a result, the intensity of the emitted light LO to be measured is substantially zero.

  According to the present embodiment, as described above with reference to FIGS. 11 to 13, the crack line CL (FIG. 11) that generates the reflected light LR is appropriate for the intensity of the emitted light LO obtained from the reflected light LR. It depends on whether or not it is formed. Therefore, it is possible to determine whether or not the crack line CL is properly formed by measuring the intensity of the emitted light LO. Thereby, the process of forming the crack line CL can be managed. By forming an appropriate crack line CL, it is possible to increase the yield of the glass substrate 4 along the crack line CL that is performed thereafter, that is, the breaking step.

  The step of irradiating the incident light LI can be performed by scanning the upper surface SF1 with the spot light SP (FIG. 10) of the incident light LI along the direction intersecting the scribe line SL. Thereby, the incident light LI can be reliably incident on the crack line CL located immediately below the trench line TL.

  The light source 21 and the sensor 22 (FIG. 6) included in the laser head 20 can be moved together by the movement of the laser head 20. In this case, the relative relationship between the generation position of the incident light LI and the observation position of the outgoing light LO is maintained. Therefore, the predetermined light path can be easily maintained in the optical measurement system. Therefore, stable measurement can be easily performed.

  Instead of the substrate holder 11 (FIG. 6), the glass substrate 4 may be fixed by other means. For example, vacuum suction or adhesive tape may be used. In addition, an interval may be provided between the glass substrate 4 and the reflecting member 10 as long as the disturbance of the optical path is not a problem. The displacement of the laser head 20 and the table 12 is performed to adjust the relative position between them. Therefore, part or all of the displacement of one of the laser head 20 and the table 12 can be replaced by the other displacement.

(Embodiment 2)
In the present embodiment, a case will be described in which the step of preparing the glass substrate 4 having the scribe line SL (FIG. 3) (FIG. 1: step S10) includes a step with a crackless state (FIG. 14).

  With reference to FIG. 15 and FIG. 16, first, the cutting tool 50 for forming the trench line TL (FIG. 5) of a crackless state (FIG. 14: step S11) is demonstrated. The cutting instrument 50 has a cutting edge 51 and a shank 52.

  The blade edge 51 is held by being fixed to a shank 52 as its holder. The blade edge 51 is provided with a top surface SD1 and a plurality of surfaces surrounding the top surface SD1. The plurality of surfaces include a side surface SD2 and a side surface SD3. The top surface SD1 and the side surfaces SD2 and SD3 face different directions and are adjacent to each other. The blade edge 51 has a vertex at which the top surface SD1, the side surfaces SD2 and SD3 merge, and the protrusion PP of the blade edge 51 is configured by this vertex. Further, the side surfaces SD2 and SD3 form ridge lines constituting the side portion PS of the blade edge 51. The side part PS extends linearly from the protrusion part PP. Moreover, since the side part PS is a ridgeline as mentioned above, it has the convex shape extended linearly. The cutting edge 51 is preferably a diamond point. That is, the cutting edge 51 is preferably made of diamond from the viewpoint that the hardness and the surface roughness can be reduced. More preferably, the cutting edge 51 is made of single crystal diamond. More preferably, crystallographically, the top surface SD1 is a {001} plane, and each of the side surfaces SD2 and SD3 is a {111} plane. In this case, although the side surfaces SD2 and SD3 have different orientations, they are crystal surfaces that are equivalent to each other in terms of crystallography. Diamond that is not a single crystal may be used. For example, polycrystalline diamond synthesized by a CVD (Chemical Vapor Deposition) method may be used. Alternatively, sintered diamond obtained by bonding polycrystalline diamond particles, which are sintered from fine graphite or non-graphitic carbon without containing a binder such as an iron group element, with a binder such as an iron group element is used. May be.

  The shank 52 extends along the axial direction AX. The blade edge 51 is preferably attached to the shank 52 so that the normal direction of the top surface SD1 is approximately along the axial direction AX.

  Next, formation of the trench line TL using the cutting tool 50 (FIG. 14: step S11) will be described below.

  Referring to FIG. 17, first, glass substrate 4 on which trench line TL is to be formed is prepared. The glass substrate 4 has a flat upper surface SF1. The edge surrounding the upper surface SF1 includes a side ED1 and a side ED2 that face each other. In the example shown in FIG. 17, the edges are rectangular. Therefore, the sides ED1 and ED2 are sides parallel to each other. In the example shown in FIG. 17, the sides ED1 and ED2 are rectangular short sides.

  Next, the blade edge 51 (FIG. 15) is pressed against the upper surface SF1 at the position N1 (FIG. 17). Details of the position N1 will be described later. Referring to FIG. 15, the cutting edge 51 is pressed such that the protrusion PP of the cutting edge 51 is disposed between the side ED1 and the side portion PS on the upper surface SF <b> 1 of the glass substrate 4 and the side portion PS of the cutting edge 51. Is arranged between the protrusion PP and the side ED2.

  Next, the cutting tool 50 is slid on the upper surface SF1. This sliding is performed between the position N1 and the position N3. A position N2 is located between the positions N1 and N3. Therefore, trench line TL is formed between positions N1 and N2 and between positions N2 and N3. The positions N1 and N3 may be located away from the edge of the upper surface SF1 of the glass substrate 4 as shown in FIG. 17, or one or both of them may be located at the edge of the upper surface SF1. The formed trench line TL is separated from the edge of the glass substrate 4 in the former case, and is in contact with the edge of the glass substrate 4 in the latter case. Of the positions N1 and N2, the position N1 is closer to the side ED1, and the position N2 of the positions N1 and N2 is closer to the side ED2. In the example shown in FIG. 17, the position N1 is close to the side ED1 of the sides ED1 and ED2, and the position N2 is close to the side ED2 of the sides ED1 and ED2, but both the positions N1 and N2 are either the side ED1 or ED2. It may be located near either.

  In the present embodiment, the blade edge 51 is displaced from the position N1 to the position N2, and is further displaced from the position N2 to the position N3. That is, with reference to FIG. 15, the blade edge 51 is displaced in a direction DA that is a direction from the side ED1 toward the side ED2. The direction DA is approximately parallel to the direction in which the side portion PS is projected onto the upper surface SF1, and is substantially directed to the direction in which the axial direction AX extending from the blade edge 51 to the shank 52 is projected onto the upper surface SF1. In this case, the blade edge 51 is dragged on the upper surface SF <b> 1 by the shank 52. That is, the pressed blade edge 51 is slid on the upper surface SF1 of the glass substrate 4 (see the arrow in FIG. 17). This sliding causes plastic deformation on the upper surface SF1 of the glass substrate 4. By this plastic deformation, a trench line TL having a groove shape is formed on the upper surface SF1. At this time, the glass substrate 4 may be slightly shaved. However, it is preferable that such shaving be as small as possible since fragments may be generated.

  The above-described process of forming the trench line TL has a crackless state in which the glass substrate 4 is continuously connected in a direction DC (FIG. 5) immediately below the trench line TL and intersecting the extending direction of the trench line TL. To be obtained. In the crackless state, the trench line TL is formed by plastic deformation, but no crack is formed along the trench line TL. Therefore, even if an external force that simply generates a bending moment or the like is applied to the glass substrate 4 as in the conventional break process, the division along the trench line TL does not easily occur. For this reason, in the crackless state, the dividing step along the trench line TL is not performed. In order to obtain a crackless state, the load applied to the blade edge 51 is so small that cracks do not occur and is large enough to cause plastic deformation.

  The crackless state is maintained for a necessary time (FIG. 14: Step S12). In order to maintain the crackless state, an operation in which excessive stress is applied to the glass substrate 4 in the trench line TL, for example, heating with application of a large external stress that causes damage to the substrate or a large temperature change, Should be avoided. While the crackless state is maintained, the glass substrate 4 may be conveyed or the glass substrate 4 may be processed.

  Referring to FIG. 18, after the crackless state is maintained, in other words, with a time lag from the formation of trench line TL, glass substrate 4 in thickness direction DT (FIG. 3) along trench line TL. Cracks are extended. Specifically, the crack of the glass substrate 4 in the thickness direction DT is extended from the position N2 toward the position N1 along the trench line TL (see the broken line arrow in the figure). As a result, a crack line CL extending along the trench line TL is formed (FIG. 14: Step S13). Formation of the crack line CL is started when the assist line AL and the trench line TL intersect each other at the position N2. For this purpose, the assist line AL is formed after the trench line TL is formed. The assist line AL is a normal scribe line with a crack in the thickness direction DT, and releases strain of internal stress in the vicinity of the trench line TL. The method of forming the assist line AL is not particularly limited, but may be formed using the edge of the upper surface SF1 as a base point as shown in FIG.

  Note that the crack line CL is less likely to be formed in the direction from the position N2 to the position N3 than in the direction from the position N2 to the position N1. That is, the ease of extension of the crack line CL has a direction dependency. Therefore, the phenomenon that the crack line CL is formed between the positions N1 and N2 but not between the positions N2 and N3 may occur. The present embodiment is intended to divide the glass substrate 4 along the positions N1 and N2, and is not intended to separate the glass substrate 4 along the positions N2 and N3. Therefore, while it is necessary to form the crack line CL between the positions N1 and N2, the difficulty of forming the crack line CL between the positions N2 and N3 is not a problem.

  As described above, the assist line AL is formed with the intention of forming the crack line CL. However, even if the assist line AL is formed, the crack line CL may not be formed, or an abnormal crack line CL (FIG. 4) may be formed. For this reason, after the assist line AL is formed, the scribe line inspection method is performed as described in the first embodiment. When the crack line CL is formed after the crackless state is maintained as in the present embodiment, the crack line CL is formed as compared with the case where the crack line CL is formed without going through the crackless state. The certainty of is reduced. The presence or absence of such a formation defect can be easily determined by the scribe line inspection method described in the first embodiment.

  In forming the trench line TL, the blade edge 51 may be displaced from the position N3 to the position N1 instead of being displaced from the position N1 to the position N3 as shown by the arrow in FIG. In this case, the blade edge 51 is displaced in the direction DB instead of the direction DA in FIG. The instrument for forming the trench line TL is not limited to the cutting edge 51 (FIG. 15), and a conical cutting edge may be used. Further, instead of the sliding blade edge, a rolled blade edge may be used. In this case, the rolling direction is preferably a direction corresponding to the direction DB (FIG. 15).

  The crack line CL can be started by applying a stress on the glass substrate 4 on the trench line TL so as to release the strain of the internal stress in the vicinity of the trench line TL. In order to generate a larger stress, the glass substrate 4 may be divided along the assist line AL. Instead of forming the assist line AL, for example, external stress may be applied by pressing the blade edge again on or near the formed trench line TL, or heating by laser light irradiation may be performed.

  The edges ED1 and ED2 of the edge of the glass substrate 4 are rectangular short sides in FIG. 17, but may be rectangular long sides. The shape of the edge is not limited to a rectangle, and may be a square, for example. Further, the sides ED1 and ED2 are not limited to a linear shape and may be a curved shape. Further, the upper surface SF1 of the glass substrate 4 is not limited to a flat one, and may be curved.

  Further, although the case where the glass substrate 4 is used as the brittle substrate has been described in detail, the brittle substrate is not limited to the glass substrate. For example, a ceramic, silicon, compound semiconductor, sapphire, or quartz substrate may be used. Good. The wavelength of the laser beam and the material of the reflecting member 10 can be appropriately selected according to the material of the brittle substrate. For example, when the brittle substrate is a silicon substrate, it is preferable to use an infrared laser.

4 Glass substrate (brittle substrate)
DESCRIPTION OF SYMBOLS 10 Reflective member 12 Table 20 Laser head 21 Light source 22 Sensor 28 Head position adjustment part 29 Amplifier 40 Inspection apparatus 50 Cutting instrument 51 Cutting edge 52 Shank AL Assist line CA, CL Crack line LI Incident light LO Output light LR Reflected light LT Transmitted light SA , SL Scribe line SF1 Upper surface (first surface)
SF2 bottom surface (second surface)
SP Spot light TL Trench line

Claims (5)

A scribe line inspection method comprising: a trench line; and a crack line extending along the trench line immediately below the trench line,
Providing a brittle substrate having a first surface and a second surface opposite to the first surface, and extending on the first surface at a position on the first surface. The scribe line having the trench line extending in a current direction is provided, and the one position of the first surface of the brittle substrate from the outside of the brittle substrate via the first surface. Irradiating the incident light by the laser directly below the optical axis direction of the incident light with the direction perpendicular to the first surface as a reference and perpendicular to the extending direction on the first surface A reflected light component directed to the second surface by the crack line reflecting the incident light, and further reflecting the reflected light from the second surface. To the outside of the brittle substrate via the first surface. A step of generating the outgoing light Cow,
Measuring the intensity of the emitted light;
A method for inspecting a scribe line.   2. The scribe line inspection method according to claim 1, wherein the step of irradiating the incident light is performed by scanning the first surface with the incident light along a direction intersecting the trench line.   3. The scribe line inspection method according to claim 1, wherein the step of generating the emitted light is performed by a reflection member disposed on the second surface reflecting the reflected light. 4. The step of irradiating the incident light is performed by emitting laser light from a light source,
The step of measuring the intensity of the emitted light is performed by a sensor detecting the emitted light,
The scribe line inspection method according to any one of claims 1 to 3, further comprising a step of moving the light source and the sensor together. The step of preparing the brittle substrate includes
Forming a trench line on the first surface of the brittle substrate so as to obtain a crackless state;
Maintaining the crackless state;
Forming a crack line extending along the trench line;
The scribe line inspection method according to any one of claims 1 to 4, further comprising:

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