Method for processing a brittle material substrate

Abstract

The present invention provides a substrate processing method that can form a groove line without cracks at a high yield rate and then change it into a groove line with cracks even for a brittle material substrate with an extremely thin plate thickness. The substrate processing method of the present invention includes: a first step of forming a groove line without cracks by pressing and fixing a scribing tool of a fixed blade and moving it in a forward direction from a position of a substrate that is apart from an edge inward as a scribing start point and a scribing end point; and a second step of forming an auxiliary line by pressing and moving a cutter wheel in a manner that intersects at an acute angle of 3 to 25 degrees with the groove line in a direction opposite to the forward direction from the intersection position to guide a crack to the groove line from the intersection position, thereby changing the groove line into a crack line with cracks.

Description

Technical Field

[0001] This invention relates to a method for processing brittle material substrates such as glass substrates for display panels such as liquid crystal displays (LCDs) and organic OLED displays, and solar cell panels. More specifically, it relates to a processing method that enables reliable, high-quality slitting processing even on thin, brittle material substrates with a thickness of 200 μm or less.

[0002] In methods for dividing glass substrates, a linear groove is formed on the substrate surface by scribing with a rotating blade wheel or the tip of a scribing tool. The scribing tool uses a fixed blade such as a pointed diamond cutter. This groove is a notch formed by plastic deformation of the substrate surface, and the linear groove is called a "scribing line".

[0003] It should be noted that in this specification, the tool that uses a fixed blade such as a sharp diamond cutter to carve grooves for plastic deformation on a substrate is called a carving tool, and not a rotating blade such as a cutting wheel.

[0004] When a scribing tool or rotary blade is placed on the edge of a substrate and then slid or rotated on the substrate to form scribing lines, such as Figure 8 As shown in (b), a crack C can extend downward from the scribing line SL at the same time as the scribing is performed. The scribing line with the crack C is referred to as the "crack line CL".

[0005] Then, if a crack line CL with the crack C is formed (at least a portion of it), in the subsequent fracture process, mechanical stress is applied by means of bending the substrate or thermal stress is applied by means of local heating (fracture treatment), so that the depth of the crack C in the crack line CL can advance in the thickness direction and extend in the line direction, thereby reliably dividing the substrate completely.

[0006] In other words, in order to completely divide the substrate, it is sufficient to establish a substrate processing method that can reliably process the crack line CL with crack C in the stage prior to the fracture processing process.

[0007] To form such a crack line CL, a trigger point (starting point crack) is required as its starting point. As mentioned above, the trigger point can be easily formed by placing the tip of a scribing tool or a rotating blade (from the outside of the substrate) on the edge of the substrate. This is because the impact when the rotating blade is placed on the edge of the substrate causes localized damage. By moving the blade tip on the blade further along the surface of the substrate, the crack line can be extended from the trigger point in the direction of the blade tip's movement. Furthermore, a scribing method that includes the edge of the substrate in the case where the blade is moved from the edge of the substrate for scribing is called "external scribing." Conversely, a scribing method that excludes the edge of the substrate and uses a position moving away from the edge of the substrate towards the inside of the substrate as the starting point (or ending point) of the scribing is called "internal scribing."

[0008] In external cutting, excessive impact from the cutting tool tip on the edge of the substrate can damage the tool tip, cause defects at the edge of the substrate, or even break the substrate. Therefore, it is essential to strictly limit the cutting tool tip's movement speed and load.

[0009] Therefore, as a method for forming trigger points without using external cutting, the applicant has previously proposed the processing methods shown in Patent Documents 1 and 2. That is, using a scribing tool or wheel with a fixed blade, scribing is performed from a position near one edge to a position near the other edge of the substrate surface, without excluding the edge, to form a shallow, groove-shaped scribing line SL (see reference 1). Figure 8 (a)). Therefore, since it is possible to perform the scribe process from the starting position without applying a strong impact to the scribe starting point, it is possible to reliably machine groove-shaped scribe lines SL without crack C. Hereinafter, the groove-shaped scribe line SL without crack C will be described (refer to...). Figure 8 (b) is called “groove line TL”.

[0010] Next, near one end of the groove line TL, an "auxiliary line" is formed by scribing with a cutting tip in a direction orthogonal to the groove line TL in Patent Document 1 and in a direction obliquely intersecting the groove line TL in Patent Document 2. Then, by performing a fracture process along the formed auxiliary line, crack C is guided to propagate in the thickness direction on the groove line TL side at the intersection of the auxiliary line and the groove line TL. (Refer to...) Figure 8 (b) and enable the crack C to extend along the groove line TL from this starting point, thus becoming the crack line CL.

[0011] In this processing method, when processing the initial scribing lines, since it is not necessary to form scribing lines accompanied by cracks C (i.e., crack lines CL), the range of scribing conditions is wider. That is, when forming trench lines TL without cracks C, even low scribing loads can be easily processed, thus producing high-quality trench lines TL with minimal damage without causing substrate breakage, and suppressing tool tip wear and damage. Furthermore, since cracks C can be guided from the intersection of the trench line TL and the auxiliary line towards the trench line TL side through the subsequent auxiliary line processing and subsequent auxiliary line fracture treatment, complete division can be achieved by applying stress to the crack line CL in the subsequent fracture treatment.

[0012] Existing technical documents

[0013] Patent documents

[0014] Patent Document 1: Japanese Patent No. 6249091;

[0015] Patent Document 2: Japanese Patent No. 6589358. Summary of the Invention

[0016] The problem the invention aims to solve

[0017] In devices such as display panels and solar cell panels, substrates with a thickness of more than 100 μm, mainly those with a thickness of more than 200 μm, are currently being processed by slitting. When slitting such thick substrates, it has been proven that slitting can be performed by using the slitting method that utilizes the auxiliary lines described in Patent Documents 1 and 2.

[0018] However, there is a strong demand for thinner and lighter-weight devices. Future research aims to achieve unprecedented ultra-thin substrate segmentation, ranging from 10μm to 100μm. When processing such ultra-thin substrates, even with the segmentation methods described in the aforementioned patent documents, there are still instances where high reliability in forming crack lines (CL) cannot be maintained, leading to a deterioration in the yield rate during processing steps before reaching the fracture treatment stage.

[0019] Therefore, the object of the present invention is to provide a method for processing brittle material substrates that can be reliably and with high yield even for extremely thin brittle material substrates by further improving the above-mentioned technology.

[0020] Solution for solving the problem

[0021] As described above, in order to achieve high-quality and reliable segmentation processing, it is necessary to reliably form crack lines with cracks along the groove lines that serve as the predetermined segmentation lines of the substrate in a stage prior to the fracture processing step. As long as crack lines can be obtained, complete segmentation can be achieved by applying mechanical or thermal stress. Therefore, the inventors have developed a substrate processing method that can stably form such crack lines even on substrates with extremely thin thicknesses.

[0022] That is, the processing method for brittle material substrates of the present invention processes the brittle material substrate in the following manner, including: a first step, on the surface of the brittle material substrate, taking a position away from the end edge inward as the starting point of the scribe and pressing a scribe tool with a fixed blade and moving it in the forward direction, taking a position away from the end edge inward as the scribe endpoint to form a groove line without cracks; and a second step, on the surface of the groove line, pressing a cutting wheel with a rotating blade and moving it in the opposite direction of the forward direction and intersecting the groove line at an acute angle θ of 3° to 25° to form an auxiliary line, thereby guiding cracks from the intersection point to the groove line, so that at least a portion of the groove line becomes a crack line with cracks.

[0023] Invention Effects

[0024] In this invention, crack-free groove lines are formed by performing the following process: The starting and ending points of the scribe are defined as the position away from the edge of the substrate, a so-called in-cut-in-cut method. The scribe load is set to a low load and pressed down within a range where the tip of the scribe tool with a fixed blade does not slip, and scribe is performed in the forward direction. Based on this, on the same surface, the scribe tool is moved at an acute angle θ intersecting the groove lines, resulting in an auxiliary line formed in the opposite direction of the forward direction. This allows for processing that guides cracks to crack-free groove lines with a high probability (over 85%), enabling substrate processing with a high yield.

[0025] Furthermore, if the cross angle θ in the second process is an acute angle of 10° to 25°, it is possible to perform processing that guides cracks with a higher probability (over 90%).

[0026] Here, a carving tool with a blade tip that serves as a fixed edge can also be used.

[0027] Alternatively, a slotted cutting wheel with a cutting edge formed on its outer peripheral edge can also be used.

[0028] Furthermore, in the above invention, an inspection process can be performed after the second process to confirm whether the crack line with cracks has been formed near the intersection position. If the crack is not guided to the groove line, an additional second process is performed to form an additional auxiliary line on the groove line at a position different from the previous intersection position.

[0029] As an inspection procedure, the formation of crack C can be confirmed, for example, by optically confirming the reflected light from crack C.

[0030] Therefore, since the inspection process has determined that the crack has not been guided to the vicinity of the intersection position, a second process can be added to guide the crack to the vicinity of the new intersection position. Thus, after adding the second process, as a whole process, a processing method that guides the crack to the side of the groove line with a high success rate can be established.

[0031] In addition, although it is possible to achieve a practically acceptable success rate (yield) by setting the second process as an additional processing step, the success rate (yield) can be further improved by repeatedly performing the second process.

[0032] Furthermore, in the above invention, the brittle material substrate can also be a glass substrate with a thickness of less than 100 μm.

[0033] While the substrate processing method of the present invention is effective in processing high-quality substrates regardless of thickness, it is particularly effective for ultra-thin glass substrates with thicknesses ranging from 10 μm to 100 μm when manufacturing them. Since there is no other effective substrate processing method for such ultra-thin substrates, it is not possible to reliably form crack lines with cracks without breaking the substrate. Attached Figure Description

[0034] Figure 1 This is a diagram illustrating an example of a scribing tool used in the substrate processing method according to Embodiment 1 of the present invention.

[0035] Figure 2 This is a cross-sectional view showing an example of a cutting wheel used in the substrate processing method according to Embodiment 1 of the present invention.

[0036] Figure 3 This is an explanatory diagram showing the first step of Embodiment 1 of the present invention.

[0037] Figure 4 This is an explanatory diagram showing the second step of Embodiment 1 of the present invention.

[0038] Figure 5 This is an explanatory diagram showing the end of the second process described above.

[0039] Figure 6 This is an explanatory diagram showing the additional second step in Embodiment 1 of the present invention.

[0040] Figure 7 yes Figure 6 A magnified view of a portion of the image.

[0041] Figure 8 (a) is a cross-sectional view showing the scribe lines (grooves) formed on the substrate without crack C. Figure 8 (b) is a cross-sectional view showing the criterion line (crack line CL) including crack C.

[0042] Figure 9 This is an explanatory diagram showing the process of Embodiment 2 of the present invention. Detailed Implementation

[0043] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. Examples of substrates that can be processed according to the present invention include glass substrates, ceramic substrates, silicon substrates, compound semiconductor substrates, sapphire substrates, and quartz substrates. Among these, the substrates that are particularly effective for processing according to the present invention are extremely thin glass substrates with a thickness of 100 μm or less, which are very difficult to cut along the predetermined cutting line.

[0044] In this embodiment, using Figure 1 The engraving tool 1 shown and Figure 2 The cutter wheel 2 is shown.

[0045] The engraving tool 1 has a cutting tip 1b composed of a frustum-shaped component supported on a base 1a. The top surface 1c of the cutting tip and the corner formed by connecting the edge 1d around the cutting tip each form a cutting tip 1e (fixed edge). Alternatively, the cutting tip 1b can also be formed as a multi-faceted frustum, such as a triangular or pentagonal frustum, instead of a frustum. Furthermore, the cutting tip 1e can also be formed at the corner of a prism or polygonal plate-shaped cutting tip 1b, with a top surface and edge forming the cutting tip 1e.

[0046] The cutting wheel 2 is an annular body with a bearing hole 2a at its center, and a cutting tip 2b is formed on its circumference with a sharp ridge at the top. Here, a cutting wheel with a diameter of 2mm and a cutting tip angle α of 110 degrees is used.

[0047] In addition, in order to efficiently and reliably guide the crack from the auxiliary line to the groove line and turn it into a crack line, this embodiment uses a grooved cutting wheel formed by a cutting tool with grooves on the outer peripheral edge (for example, see Japanese Patent Application Laid-Open No. 9-188534 for grooved cutting wheels).

[0048] Furthermore, the cutting tip 1b and the cutting wheel 2 of the aforementioned engraving tool are made of ultra-hard materials such as diamond and superhard alloy.

[0049] Next, a substrate processing method according to one embodiment of the present invention will be described. The present invention is an improvement on the substrate slitting method described in Patent Documents 1 and 2, which consists of the following steps: (a) a first step of forming a groove line on a substrate as a groove-shaped scribing line without cracks; (b) a second step of guiding cracks to at least a portion of the groove line to form a crack line; and (c) a fracture processing step of applying stress to the crack line to completely slit the substrate. By improving the substrate processing in steps (a) and (b) before the fracture processing in (c), i.e., the first step and the second step, it is possible to achieve substrate processing that can reliably guide cracks to the groove-shaped groove line without cracks to form a crack line with high reliability.

[0050] <Implementation Method 1>

[0051] In the following description of Embodiment 1, although an example of the substrate processing method of the present invention will be described, in order to facilitate the explanation of the statistical verification results (effects) of the processing method, multiple trench lines are formed, so the substrate shape and the processing method of the trench lines used for statistics will also be described.

[0052] First, such as Figure 3 As shown, a glass substrate W (hereinafter referred to as "substrate") with a flat surface is prepared, which, when viewed from top, is a quadrilateral with sides 3a, 3b and 4a, 4b facing each other on all four sides. As for the thickness of the substrate used, a substrate with a thickness of 100 μm or less, which is particularly difficult to process, is preferably prepared, specifically a substrate with a thickness of 10 to 100 μm. In the verification examples of the present invention, substrates with thicknesses of 30 μm and 50 μm were used.

[0053] Next, as the first step in substrate processing, the tip 1e of the scribing tool 1 is pressed onto the surface of the substrate W at position N1 (scrubbing start point). Position N1 is a position away from the edge of the substrate W and close to edge 3a. Then, with the tip 1e pressed against the surface of the substrate, a groove line TL is formed by scribing in a straight line from position N1 to position N2 (scrubbing end point) close to the opposite edge 3b. This direction is defined as the forward direction. Figure 8 As shown in (a), the trench line TL is a shallow groove formed on the surface of the substrate W, without the formation of a crack C extending in the thickness direction. Therefore, a lower load can be selected than in the case of forming a scribing line SL (crack line CL) with crack C, and scribing processing for forming the trench line can be performed under a wider range of scribing conditions.

[0054] Then, using the same method as described above, a plurality of parallel trench lines TL (only 4 are shown in the figure) are formed on the surface of the substrate W at specified intervals. In the verification of the present invention, the required number of trench lines (e.g., 50 trench lines TL) are processed on a substrate at 30 mm intervals.

[0055] Next, as Figure 4 As shown, as a second step, an auxiliary line AL1 is formed on the same surface of the substrate W as the surface where the groove lines TL are formed, using a cutting wheel 2. In this embodiment, the auxiliary line AL1 intersects the groove line at an angle θ at one end of each groove line TL, near the edge 3b (the end point of the scribe line). In the opposite direction of the forward direction, the auxiliary line AL1 is formed with an intersection angle (entry angle) θ with the groove line TL in the range of 3 to 25° (more preferably 10 to 25°). The cutting wheel 2 starts scribes from the inside of the edge away from the substrate surface until it passes the N3 position of the intersection point P with the groove line TL, at which point the formation of the auxiliary line AL1 ends. The auxiliary line AL1 can be any crack line CL with crack C formed.

[0056] By using an auxiliary line AL1 that intersects the groove line TL in the opposite direction of its forward direction, the crack C extending in the thickness direction is guided at least to the groove of the groove line TL near the intersection point P. The crack C may extend longer to the side of the groove line TL depending on environmental and scribing conditions, and may sometimes extend shorter, only to the vicinity of the intersection point P. However, in either case, it can reliably extend along the entire groove line through subsequent stress application; therefore, it is sufficient that the crack C can be guided to a portion of the groove. Thus, the groove line TL can be transformed into... Figure 8 (b) shows the crack line CL with crack C. Figure 5 ).

[0057] Then, using the optical inspection method described below, the cross angle (entry angle) θ was varied as a parameter to verify whether crack C was guided. The results showed that when the plate thickness was 50 μm, if θ was in the range of 3–25°, crack C was guided with a 100% success rate in 5 measurements. Furthermore, to improve the verification accuracy, θ was set to 10° and 25°, and approximately 50 measurements were performed respectively. The results verified that crack C was guided with a probability of over 96% in each measurement (see Verification Examples 1 and 2 described later).

[0058] Furthermore, when the plate thickness was 30 μm, it was also verified that by optimizing the intersection angle θ of the auxiliary lines formed by the cutter wheel, the scribing speed, and the scribing setting pressure, crack C was guided with a probability of 94–96% in 50 measurements (see verification examples 3 and 4 described later).

[0059] The optical inspection method for the crack C used in the verification is explained. It is known that if light is shone near the intersection P of the groove line TL and the auxiliary line, then when the crack C is guided to the side of the groove line TL, reflected and scattered light from the crack C can be obtained at that location. Therefore, if the reflected and scattered light from the crack C is detected by visual inspection or by automatic inspection using an inspection device with a light-receiving element, it can be applied to the inspection process to measure whether the guidance of the crack C was successful.

[0060] While it has been confirmed that the first and second processes described above can guide crack C to trench line TL with a specified success rate for an extremely thin substrate of 50 μm, it is desirable to establish a substrate processing method that can successfully guide crack C with an even higher success rate. Therefore, a third process (additional second process) as described below has been added.

[0061] That is, in the second step, the optical inspection method described above is used to confirm whether the crack C has been successfully guided to the groove line TL, and to detect whether there is an incomplete crack line CL' of the crack C and its location.

[0062] Then, a second auxiliary line AL2 is formed for the detected incomplete crack lines CL' (groove lines). For example... Figure 6 and Figure 7 As shown in the enlarged view, the second auxiliary line AL2 is formed parallel to and slightly offset from the first auxiliary line AL1. In this embodiment, it is formed at a position offset by a gap L, for example 3 mm, from the inner side of the substrate (the side to be separated) compared to the intersection point P of the first auxiliary line AL1 and the incomplete crack line CL'. It intersects the crack line CL' and ends at position N4. By processing this second auxiliary line AL2, the incomplete crack line can be guided to guide the crack with the same success probability as the previous one. Then, by repeating the same auxiliary line processing multiple times during the inspection process, the success probability of guiding crack C can be increased (to 100%) (see Verification Example 2 described later).

[0063] The above describes the substrate processing method of the present invention, which is able to guide the crack C to the trench line on an extremely thin substrate. After the crack line CL is formed, the desired slitting process can be achieved by using a conventional fracture treatment device that can apply mechanical or thermal stress along the crack line CL.

[0064] (Verification Example 1)

[0065] Objective: To determine the range of the optimal cross angle (entry angle) θ for successfully guiding crack C to the groove line TL.

[0066] Groove lines TL were formed on a 50μm substrate (alkali-free glass) using scribing tool 1. Next, when the cross angle (entry angle) θ was varied as a parameter in the range of 1° to 85°, and an auxiliary line AL was formed using a grooved cutter wheel 2, the success rate (yield) of forming crack C on the groove line TL corresponding to θ was verified (cross angles of θ from 90° to 180° were also verified, but the verification results were omitted because the success rate was low in the overall range).

[0067] The main setup conditions and measurement methods for verification are shown below.

[0068] First step:

[0069] The pressure setting for the engraving tool is 0.04 MPa.

[0070] The engraving speed of the engraving tool is 50 mm / sec.

[0071] Second process:

[0072] The set pressure of the cutter wheel is 0.10 MPa.

[0073] The engraving speed of the cutter wheel is 5 mm / sec.

[0074] Verification was performed for every 1° of the cross angle θ, which ranges from 1 to 85°, and for every 5° of the cross angle θ, which ranges from 1 to 5°.

[0075] Perform 5 measurements (N times) for a given θ to confirm whether crack C is successful, and calculate the success rate (yield).

[0076] [Table 1]

[0077]

[0078] Verification of Example 1 results: As shown in Table 1, at least one crack C was not formed (unsuccessful) when the cross angle θ was 1°, 2° and 30-85° (except 60°), while the success rate (yield rate) was 100% when θ was 3°-25°.

[0079] (Verification Example 2)

[0080] Objective: To specifically study the success rate of a portion of the optimal cross angle (entry angle) θ discovered by verification example 1, and to confirm that the success rate becomes 100% by adding a second step.

[0081] • First step: (Same as verification example 1)

[0082] The pressure setting for the engraving tool is 0.04 MPa.

[0083] The engraving speed of the engraving tool is 50 mm / sec.

[0084] Second process:

[0085] The set pressure of the cutter wheel is 0.10 MPa.

[0086] The engraving speed of the cutter wheel is 5 mm / sec.

[0087] Within the optimal cross angle θ range of 3 to 25° obtained from Verification Example 1, 50 measurements were performed at 10° and 25° to confirm the success of crack C and calculate the success rate (SSP). For lines that did not succeed the first time, an auxiliary line was formed by adding a second process to confirm the success of crack C again, and the success rate and yield were calculated.

[0088] [Table 2]

[0089]

[0090] Verification of Example 2 results: As shown in Table 2, through 50 measurements, a success rate of 96% was achieved for both cross angles θ of 10° and 25°. Furthermore, the results of adding a second process (second cutting) to the two lines that failed in the first attempt, as well as the results of cracks C forming during these processes, all achieved a 100% success rate.

[0091] (Verification Example 3)

[0092] Objective: To specifically investigate the success rate (yield) of the optimal cross angle (entry angle) θ on a portion of a substrate that is thinner (30 μm) than that of Verification Example 1.

[0093] First step:

[0094] The pressure setting for the engraving tool is 0.03 MPa.

[0095] The engraving speed of the engraving tool is 50 mm / sec.

[0096] Second process:

[0097] The set pressure of the cutter wheel is 0.10 MPa.

[0098] The engraving speed of the cutter wheel is 20 mm / sec.

[0099] Forty-nine measurements were performed on 15°, one of the optimal cross angles obtained from the preliminary measurements (preliminary measurements used to determine the optimal cross angle range θ in the same way as in verification 1), to confirm whether crack C was successful and to determine the success rate and yield.

[0100] [Table 3]

[0101]

[0102] The results of Example 3 are shown in Table 3. With 49 measurements, a success rate of 85.7% was achieved with a cross angle θ of 15°.

[0103] (Verification Example 4)

[0104] Objective: In the verification of the substrate (30μm) of Example 3 with the optimal cross angle θ of 15°, to further investigate the success rate when the scribing speed and set pressure are varied as parameters.

[0105] First step:

[0106] The pressure setting for the engraving tool is 0.03 MPa.

[0107] The engraving speed of the engraving tool is 50 mm / sec.

[0108] Second process:

[0109] The set pressure of the cutter wheel is 0.05 to 0.20 MPa.

[0110] The engraving speed of the cutter wheel is 5 to 100 mm / sec.

[0111] By changing the combination of the setting conditions of the cutting wheel pressure and the setting conditions of the scribing speed, and taking 50 (49) measurements with the optimal cross angle θ of 15°, the success rate and yield of the crack C can be determined.

[0112] [Table 4]

[0113] speed Set pressure Finished Product Rate SSP success rate 20mm / sec 0.10MPa 42 / 49 85.7％ 20mm / sec 0.20MPa 32 / 50 64％ 20mm / sec 0.05MPa 46 / 50 92％ 100mm / sec 0.10MPa 33 / 50 66％ 5mm / sec 0.05MPa 47 / 50 94％ 5mm / sec 0.10MPa 47 / 50 94％ 5mm / sec 0.15MPa 48 / 50 96％

[0114] The results of Example 4 are shown in Table 4. Within the parameter setting range, changing the scribing speed has a greater impact than changing the set pressure. In particular, when the scribing speed is set to 5 mm / sec, a success rate of 94-96% is obtained at 0.05-0.15 MPa.

[0115] <Implementation Method 2>

[0116] In Embodiment 1, an example of processing multiple straight lines on a substrate was described. This embodiment can be applied to the case of cutting a square substrate into strips.

[0117] On the other hand, in the following Embodiment 2, an example of performing non-linear processing on the substrate will be described. Here, the processing of cutting out a closed curve will be described.

[0118] like Figure 9As shown, on the substrate W, position N1 is used as the starting point for scribes, passing through positions N2 and N3 to reach position N4, the ending point for scribes. Using the scribe tool 1, a scribe line TL in the form of a figure-6 is formed in one pass along this direction. At this time, a closed curve portion from N1 to N3 and a non-closed curve portion (removed portion) from N3 to N4 are formed.

[0119] Next, an auxiliary line is formed on the non-closed curve portion between N3 and N4 near the end of the incision. That is, an auxiliary line AL1 is formed from position N5 to position N6 at an intersection angle of 3° to 25° in the opposite direction to the direction of travel when the groove line TL is formed. This allows the crack C to be guided to the groove line TL between N3 and N4, and the groove line TL from this portion to the closed curve portion can be transformed into the crack line CL. Therefore, thereafter, by applying thermal stress (not particularly limited to light, heat, hot and cold spraying, etc.) to the closed curve portion, segmentation processing can be performed by penetrating along the closed curve.

[0120] While representative embodiments of the present invention have been described above, the present invention is not necessarily limited to the above-described embodiments. For example, although substrates with a thickness of 100 μm or less made of brittle material are used as processing targets in the above embodiments, the invention can be applied to substrates with a thickness of 100 μm or more. Furthermore, the present invention can be appropriately modified and altered to achieve its objectives without departing from the scope of the claims.

[0121] Industrial availability

[0122] The method of the present invention can be used for substrate processing before fracture treatment when splitting brittle material substrates such as glass substrates.

[0123] Explanation of reference numerals in the attached figures

[0124] AL1: The first auxiliary line;

[0125] AL2: The second auxiliary line;

[0126] C: Crack;

[0127] CL: Crack line;

[0128] SL: Scribe line;

[0129] W: substrate;

[0130] 1: Engraving tools;

[0131] 2: Cutter wheel;

[0132] 3a: One edge of the substrate;

[0133] 3b: The other side of the substrate.

Claims

1. A processing method of a brittle material substrate, comprising: a first process of, on a surface of a brittle material substrate, pressing a scribing tool having a fixed blade against the surface of the substrate and moving the scribing tool in a forward direction, with a position of the substrate away from an edge toward an inner side as a scribing start point, to form at least one groove line in a groove shape without a crack, with a position of the substrate away from the edge toward the inner side as a scribing end point; and a second process of, on the surface of the substrate, pressing a cutter wheel having a rotating blade against the groove line and moving the cutter wheel in a manner of intersecting the groove line at an acute angle θ of 3° to 25° in a direction opposite to the forward direction, to form an auxiliary line, which is a crack line formed with a crack, thereby guiding the crack from an intersection position to the groove line and changing at least a part of the groove line into the crack line with the crack. The brittle material substrate has a plate thickness of 100 μm or less.

2. The processing method of the brittle material substrate according to claim 1, wherein the intersection angle θ in the second process is an acute angle of 10° to 25°.

3. The processing method of the brittle material substrate according to any one of claims 1 to 2, wherein the scribing tool uses a scribing tool having a blade tip with a tip corner as a fixed blade.

4. The processing method of the brittle material substrate according to any one of claims 1 to 2, wherein the cutter wheel is a grooved cutter wheel formed with a blade having a groove formed in an outer peripheral ridge line.

5. The processing method of the brittle material substrate according to any one of claims 1 to 2, wherein a checking process is performed after the second process to confirm whether or not the crack line with the crack is formed in the vicinity of the intersection position, when the crack is not guided to the groove line, an additional second process for forming an additional auxiliary line in a position different from the intersection position of the previous time on the groove line is performed.

6. The processing method of the brittle material substrate according to any one of claims 1 to 2, wherein the brittle material substrate is a glass substrate having a plate thickness of 100 μm or less. ​

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