JP2016069195A - Substrate segmentation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably segment a substrate along lines crossing each other in a plane layout.SOLUTION: A first trench line TL1 is formed by sliding a tip pressed to a first main face SF1 of a first brittle substrate 11. The first trench lie TL1 is formed so as to get a crack free state. A first crack line CL1 is formed by extending a crack along the first trench line TL1. Continuity of the first brittle substrate 11 is broken by the first crack line CL1 in the direction crossing the first trench line TL1 right under the first trench line TL1. A second crack line CL2 is formed on a second main face SF2. The first brittle substrate 11 is segmented along each of the first and the second crack lines CL1 and CL2.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for dividing a substrate made of a brittle material.

  2. Description of the Related Art Conventionally, in order to define a position where a brittle substrate such as a glass substrate is cut, a scribe line is mechanically formed using a cutter. At the same time as the scribe line is formed, a crack along the scribe line is also formed (see, for example, Patent Document 1). When the scribe line is formed, the crack does not reach the surface opposite to the surface on which the scribe line is formed. After that, by applying a stress called a break process, the crack is completely extended in the thickness direction, so that the substrate is divided.

JP-A-9-188534

  The inventor has independently studied a dividing method using a trench (referred to as a trench line) extending on the substrate without a crack. Internal stress is accumulated in the vicinity of the trench line in the substrate, and a crack line along the trench line can be formed by performing a process of releasing it at an arbitrary timing. The subsequent break process is the same as the conventional method.

  Depending on the position where the line is formed, the trench line is likely to be formed more stably than the conventional scribe line. This is the case, for example, when forming a line from a starting point away from the edge of the substrate. Also, a substrate with a conventional scribe line is likely to be broken at an inappropriate timing due to unintended extension of the crack, but such a phenomenon occurs in a substrate with a trench line not accompanied by a crack. Is unlikely to occur.

  As described above, the method of defining the dividing position of the substrate by the trench line without cracks has various advantages. On the other hand, according to further studies by the present inventors, it has been found that when trench lines that intersect each other are formed on the same surface of the substrate, it is difficult to stably form crack lines along the trench lines. If the formation of the crack line is unstable, the break process, which is a process for completely extending the crack in the thickness direction, also becomes unstable. Since it is often required to divide the substrate along lines that intersect each other in the planar layout, a method that can stably form a crack line from a trench line is desired even in such a case.

  The present invention has been made to solve the above-described problems, and its purpose is to use a trench line without a crack as a part of a line for defining a position where the substrate is divided. The present invention provides a substrate cutting method capable of stably dividing a substrate along lines intersecting each other in a planar layout.

  The substrate cutting method of the present invention includes the following steps. A first brittle substrate having a first main surface and a second main surface opposite to the first main surface and having a thickness direction perpendicular to the first main surface is prepared. The cutting edge is pressed against the first main surface of the first brittle substrate. By causing plastic deformation on the first main surface of the first brittle substrate by sliding the pressed blade edge on the first main surface of the first brittle substrate, at least the groove shape is obtained. One first trench line is formed. In the step of forming the first trench line, a crackless state is obtained in which the first brittle substrate is continuously connected in the direction intersecting the first trench line immediately below the first trench line. It is done as follows. At least one first crack line is formed by extending a crack in the first brittle substrate in the thickness direction along the first trench line. The first brittle substrate is disconnected from the first crack line immediately below the first trench line in the direction intersecting the first trench line. A second crack line is formed on the second main surface of the first brittle substrate. The first brittle substrate is divided along each of the first and second crack lines. The first and second crack lines intersect each other in the planar layout.

  According to the present invention, the process of forming the first crack line from the first trench line is performed on the first main surface, and the process of forming the second crack line is performed on the second main surface. Is called. Thereby, the first and second crack lines can be formed without being affected by the intersecting crack lines in the planar layout. Specifically, the first crack line can be formed from the first trench line without being affected by the second crack line, and the second crack is not affected by the first crack line. A line can be formed. Therefore, the first and second crack lines can be stably formed regardless of whether or not the first and second crack lines intersect in the planar layout. Therefore, the first brittle substrate can be stably provided along the lines intersecting each other in the planar layout while using the first trench line as a part of the line for defining the position where the first brittle substrate is divided. Can be divided.

FIG. 1A is a side view schematically showing the configuration of the instrument used in the substrate cutting method according to Embodiment 1 of the present invention, and the configuration of the cutting edge of the instrument is outlined from the viewpoint of arrow IB in FIG. It is a top view (B) shown in figure. It is a top view (A)-(C) showing roughly each of the 1st-3rd process of the parting method of the substrate in Embodiment 1 of the present invention. 2A to 2C are planar layout diagrams (A) to (C) in which a trench line is indicated by a broken line, a crack line is indicated by a solid line, and an arrow indicating a line forming direction is attached. . It is the end view (A) which shows schematically the structure of the trench line formed in the board | substrate cutting method in Embodiment 1 of this invention, and the end view (B) which shows schematically the structure of a crack line. It is a top view which shows 1 process of the cutting method of the board | substrate in a comparative example. In each of the first to third steps of the comparative example, the trench line is indicated by a broken line, the crack line is indicated by a solid line, and the plane layout diagrams (A) to (C) with arrows indicating the line forming direction are attached. is there. In the step of the substrate cutting method according to the second embodiment of the present invention, the schematic plan layout diagram (A) to FIG. 9A, in which the trench line is indicated by a broken line, the crack line is indicated by a solid line, and an arrow indicating the line forming direction is attached. (C). It is the top view (A) and (B) which each shows roughly each of the 1st and 2nd process of the cutting method of the board | substrate in Embodiment 3 of this invention. It is a top view which shows roughly 1 process of the cutting method of the board | substrate in Embodiment 4 of this invention. The side view (A) which shows schematically the structure of the instrument used for the board | substrate cutting method in Embodiment 5 of this invention, and the structure of the blade edge | tip which the said instrument has is outlined from the viewpoint of arrow XB of FIG. 10 (A). It is a top view (B) shown in figure.

  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)
Referring to FIGS. 1A and 1B, a cutting instrument 50 used in the substrate cutting method in the present embodiment has a blade edge 51 and a shank 52. The blade edge 51 is held by a shank 52 as its holder.

  The blade edge 51 is provided with a top surface SD1 (first surface) and a plurality of surfaces surrounding the top surface SD1. The plurality of surfaces include a side surface SD2 (second surface) and a side surface SD3 (third surface). 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, polycrystalline diamond sintered from fine graphite or non-graphitic carbon without containing a binder such as an iron group element, or sintered diamond obtained by bonding diamond particles with a binder such as an iron group element May be used.

  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, the substrate cutting method of this embodiment will be described below.

  A glass substrate 11 (first surface) having an upper surface SF1 (first main surface) and a lower surface SF2 (second main surface opposite to the first main surface) and having a thickness direction DT perpendicular to the upper surface SF1. A brittle substrate) is prepared.

  The blade edge 51 is pressed against the upper surface SF1 of the glass substrate 11. Specifically, the protrusion part PP and the side part PS of the blade edge 51 are pressed in the thickness direction DT of the glass substrate 11.

  Next, the pressed blade edge 51 is slid in the direction DA on the upper surface SF1. The direction DA is obtained by projecting the direction extending from the protrusion PP along the side part PS onto the upper surface SF1, and roughly corresponds to the direction in which the axial direction AX is projected onto the upper surface SF1. When sliding, the blade edge 51 is dragged on the upper surface SF 1 by the shank 52. By this sliding, plastic deformation is generated on the upper surface SF <b> 1 of the glass substrate 11.

  Furthermore, referring to FIGS. 2A and 3A, trench line TL1 (first trench line) having a groove shape toward direction DA (rightward in the figure) by the plastic deformation described above. Is formed. In this embodiment, trench line TL1 includes trench lines TL1a to TL1c and TL1t.

  Referring to FIG. 4A, the step of forming trench line TL1 is a crackless state in which glass substrate 11 is continuously connected in a direction DC intersecting trench line TL1 immediately below trench line TL1. Is carried out to obtain In the crackless state, although the trench line TL1 is formed by plastic deformation, no crack is formed along the trench line TL1. 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.

  Next, a trench line TL2 (second trench line) is formed on the lower surface SF2 of the glass substrate 11 by a method substantially similar to the method for forming the trench line TL1 described above. The number of trench lines TL2 is arbitrary, and the trench line TL2 of the present embodiment includes trench lines TL2a to TL2d. The order in which the trench lines TL1 and TL2 are formed is not particularly limited.

  In the planar layout (FIG. 3A), at least one of the trench lines TL1a to TL1c and at least one of the trench lines TL2a to TL2d intersect each other. In the present embodiment, each of trench lines TL1a to TL1c intersects with each of trench lines TL2a to TL2d. In the planar layout, the trigger trench line TL1t intersects each of the trench lines TL2a to TL2d.

  Next, the glass substrate 11 is divided along the dividing line BL intersecting with each trench line TL1 in the planar layout. This division can be performed by ordinary techniques. For example, formation of a scribe line along the dividing line BL and division by a break process along the scribe line are performed.

  Further, referring to FIG. 2B and FIG. 3B, the glass substrate 11 in the thickness direction DT (FIG. 4B) along the trench line TL1 triggered by the division along the division line BL described above. The crack is extended. As a result, a crack line CL1 (first crack line) is formed. Specifically, crack lines CL1a to CL1c and CL1t are formed from trench lines TL1a to TL1c and TL1t, respectively. The crack line CL1t is also referred to as a trigger crack line in view of its function described later.

  The extension direction of the crack line CL1 (see the arrow in FIG. 3B) is opposite to the direction in which the trench line TL1 is formed (see the arrow in FIG. 3A) in the present embodiment. In other words, the direction in which the crack extends along the trench line TL1 is opposite to the direction DA (FIG. 1A) in which the blade edge 51 slides in the process of forming the trench line TL1. That is, the ease of extending the crack line CL1 has direction dependency. This direction dependency is presumed to be caused by the distribution of internal stress generated in the glass substrate 11 when the trench line TL1 is formed.

  Directly below the trench line TL1, the glass substrate 11 has a continuous connection broken by the crack line CL1 in the direction DC (FIG. 4B) intersecting the trench line TL1. Here, “continuous connection” means a connection that is not interrupted by a crack. In addition, in the state where the continuous connection is broken as described above, the portions of the glass substrate 11 may be in contact with each other through the cracks of the crack line CL1.

  Next, the glass substrate 11 is divided along the trigger crack line CL1t. This division can be performed, for example, by bending the glass substrate 11 by applying an external force to the glass substrate 11.

  Further, referring to FIG. 2C and FIG. 3C, by the above-mentioned division, the crack of the glass substrate 11 in the thickness direction is extended along the trench line TL2. As a result, a crack line CL2 (second crack line) is formed on the lower surface SF2 of the glass substrate 11. Since trench lines TL1 and TL2 (FIG. 3A) intersect with each other in the planar layout, crack lines CL1 and CL2 (FIG. 3C) also intersect with each other in the planar layout. The extension direction of the crack line CL2 (see the arrow in FIG. 3B) is opposite to the formation direction of the trench line TL2 (see the arrow in FIG. 3A) in this embodiment.

  Next, the glass substrate 11 is divided along each of the crack lines CL1 and CL2. That is, a so-called break process is performed. The break process can be performed, for example, by bending the glass substrate 11 by applying an external force to the glass substrate 11.

  In the above, the glass substrate 11 is divided along the dividing line BL in order to obtain a trigger of the crack line CL1, but a sufficient trigger may be obtained only by forming a scribe line along the dividing line BL. In that case, the division along the scribe line can be omitted.

  Next, a comparative example will be described below.

  Referring to FIGS. 5 and 6A, trench lines TL1x and TL1y intersecting each other in the planar layout are both formed on upper surface SF1 of glass substrate 11. Next, the glass substrate 11 is divided along a dividing line BL that intersects with each of the trench lines TL1x in the planar layout.

  With reference to FIG. 6B, the crack line CL1x is formed along the trench line TL1x, triggered by the division. With the formation of the crack line CL1x as a trigger, the crack line CL1y is formed along the trench line TL1y. However, a crack may not be formed in a part of the trench line TLy depending on the type of substrate and the scribe conditions. In the trench line TL1y, it is highly uncertain whether cracks are formed in all of the portions where cracks are scheduled to be formed.

  Further, referring to FIG. 6C, further formation of crack line CL1y along trench line TL1y may occur, triggered by the division along one of crack lines CL1x. However, as with the formation of the crack line CL1y triggered by the formation of the crack line CL1x, in this process as well, it is uncertain whether cracks will be formed in all the portions of the trench line TL1y where the cracks were planned to be formed. High nature.

  As described above, in this comparative example, due to the influence of the previously formed intersecting crack lines CLx, are crack lines CLy formed in all of the trench lines TLy where cracks are scheduled to be formed? The uncertainty about is high. That is, it is difficult to stably form all planned crack lines CLy formed later. If the formation of the crack line is unstable, the break process, which is a process for completely extending the crack in the thickness direction, also becomes unstable.

  On the other hand, according to the present embodiment, the process of forming the crack line CL1 from the trench line TL1 (FIG. 2B and FIG. 3B) is performed on the upper surface SF1 to form the crack line CL2. 2C and 3C are performed on the lower surface SF2, so that cracks can be generated from the trench line TL2 without being affected by the crack line CL1 formed earlier and intersecting in the planar layout. Therefore, the crack line CL2 can be stably formed from the trench line TL2 regardless of whether or not the crack lines CL1 and CL2 intersect in the planar layout. The trench line TL1 is not affected by the crack line CL2 that intersects The crack line CL1 can be stably formed, so that the glass substrate 11 can be stably formed using the trench lines TL1 and TL2 that intersect each other in the planar layout as a line that defines the position where the glass substrate 11 is divided. Can be divided.

  Further, in order to give the glass substrate 11 a trigger for forming the crack line CL2 from the trench line TL2, the cutting along the trigger crack line CL1t (FIGS. 2B and 3B) included in the crack line CL1 is performed. Is done. Thereby, the crack line CL2 can be easily formed from the trench line TL2.

  In the present embodiment, the blade edge 51 is slid toward the direction DA (FIGS. 1A and 1B) to form the trench lines TL1 and TL2, but instead, the slid toward the direction DB. It may be moved. In this case, the direction in which the crack extends along the trench lines TL1 and TL2 is the same as the direction DB (FIG. 1A) in which the blade edge 51 slides in the process of forming the trench lines TL1 and TL2. Therefore, in order to make the extension direction of the cracks the same as in FIGS. 3B and 3C, the formation direction of the trench lines TL1 and TL2 may be opposite to that in FIG.

(Embodiment 2)
In the present embodiment, after the same steps as those up to FIG. 3B are performed, the glass substrate 11 is divided along the crack line CL1a. As a result, as shown in FIG. 7A, the crack line CL2 is formed on the trench line TL2 (FIG. 3B) on one side of the crack line CL1a (the side where the crack line CL1b or the like is not formed). It is formed. Further referring to FIGS. 7B and 7C, next, the glass substrate 11 is divided in this order along the crack lines CL1b, CL1c, and CL1t, thereby further forming the crack line CL2. That is, the trench line TL2 located in either the direction DA or the direction DB (FIGS. 1A and 1B) according to the sliding direction of the blade edge 51 from the location divided by the crack lines CL1a to CL1c, CL1t. The crack line CL2 is formed in the portion. The order of dividing the crack lines CL1a to CL1c, CL1t is not limited to this, and may be divided in any order.

  Since the configuration other than the above is substantially the same as the configuration of the first embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof is not repeated.

  According to the present embodiment, not only the crack line CL1t but also the crack lines CL1a to CL1c can function as trigger crack lines.

(Embodiment 3)
Referring to FIG. 8A, also in the present embodiment, trench line TL1 is formed by the same method as in the first embodiment (FIGS. 2A and 3A). On the other hand, in the present embodiment, crack line CL2 on lower surface SF2 is formed as a normal scribe line. For example, the crack line CL2 is directly formed by displacing the blade edge on the lower surface SF2 of the glass substrate 11 along the line where the crack line CL2 is to be formed.

  Further, referring to FIG. 8B, the glass substrate 11 is divided along the dividing line BL as in the first embodiment. Thereby, the crack line CL1 is formed.

  According to this embodiment, while using trench line TL1 as a part of a line for defining a position where glass substrate 11 is divided, glass substrate 11 is stably provided along lines that intersect each other in a planar layout. Can be divided.

  Note that the split line BL (FIG. 8A) is not particularly provided, and the crack line CL1 may be formed by dividing the glass substrate 11 at the crack line CL2. At this time, the order of dividing the crack line CL2 may be any order as in the case of dividing the crack line CL1 of the second embodiment.

(Embodiment 4)
Referring to FIG. 9, in the present embodiment, after the step of forming trench lines TL1 and TL2 in glass substrate 11 (see FIG. 2A), trench line TL1 is at least partially covered. The glass substrate 12 (second brittle substrate) is bonded to the glass substrate 11. Thereby, a cell substrate having glass substrates 11 and 12 is obtained.

  Next, crack lines CL <b> 1 and CL <b> 2 are formed on the glass substrate 11 by the same process as in FIGS. Thereby, the glass substrate 11 can be divided along the crack lines CL1 and CL2. On the other hand, the position where the glass substrate 12 is to be divided can be defined, for example, by forming a normal scribe line. By the above, the position where the cell substrate having the glass substrates 11 and 12 is divided is defined. Next, the cell substrate is divided by performing a break process.

  According to the present embodiment, trench line TL1 is formed in advance in the portion of upper surface SF1 of glass substrate 11 that is covered by glass substrate 12. Thereby, crack line CL1 can be formed from trench line TL1 also in the part covered by glass substrate 12 among upper surfaces SF1 of glass substrate 11.

  Further, at the time when the glass substrate 12 is bonded to the glass substrate 11, the crack line CL1 has not yet been formed on the upper surface SF1 of the glass substrate 11. Therefore, it is prevented that the glass substrate 11 is unintentionally divided during the bonding operation.

(Embodiment 5)
With reference to FIG. 10 (A) and (B), in each said embodiment, the blade edge | tip 51v may be used instead of the blade edge | tip 51 (FIG. 1 (A) and (B)). The blade edge 51v has a conical shape having a vertex and a conical surface SC. The protruding part PPv of the blade edge 51v is constituted by a vertex. The side portion PSv of the blade edge is configured along a virtual line (broken line in FIG. 10B) extending from the apex to the conical surface SC. Thereby, the side part PSv has a convex shape extending linearly.

  In addition to the glass substrate, for example, a ceramic substrate made of low-temperature fired ceramics or high-temperature fired ceramics, a silicon substrate, a compound semiconductor substrate, a sapphire substrate, or a quartz substrate may be used as the brittle substrate in each of the above embodiments. .

CL1 crack line (first crack line)
CL2 crack line (second crack line)
SF1 Upper surface (first main surface)
SF2 Lower surface (second main surface)
TL1 trench line (first trench line)
TL2 trench line (second trench line)
11 Glass substrate (first brittle substrate)
12 Glass substrate (second brittle substrate)
50 Cutting tool 51, 51v Cutting edge

Claims (5)

Providing a first brittle substrate having a first main surface and a second main surface opposite to the first main surface and having a thickness direction perpendicular to the first main surface;
Pressing the blade edge against the first main surface of the first brittle substrate;
The first brittleness is caused by sliding the blade edge pressed by the step of pressing the blade edge against the first main surface of the first brittle substrate on the first main surface of the first brittle substrate. Forming at least one first trench line having a groove shape by generating plastic deformation on the first main surface of the substrate, and forming the first trench line comprises: The first brittle substrate is directly below the first trench line so as to obtain a crackless state in which the first brittle substrate is continuously connected in a direction intersecting the first trench line. At least one first crack line is formed by extending a crack of the first brittle substrate in the thickness direction along one trench line The first brittle substrate is disconnected from the first crack line immediately below the first trench line by the first crack line in a direction intersecting the first trench line, and Forming a second crack line on the second main surface of the first brittle substrate;
Cutting the first brittle substrate along each of the first and second crack lines,
The substrate cutting method, wherein the first and second crack lines intersect each other in a planar layout. The step of forming the second crack line includes:
Pressing the blade edge against the second main surface of the first brittle substrate;
The first brittleness is caused by sliding the blade edge pressed by the step of pressing the blade edge against the second main surface of the first brittle substrate on the second main surface of the first brittle substrate. Forming a second trench line having a groove shape by generating plastic deformation on the second main surface of the substrate, and the step of forming the second trench line includes the step of forming the second trench line. A crackless state in which the first brittle substrate is continuously connected in a direction intersecting the second trench line immediately below the trench line, and the second trench is further obtained. The substrate cutting method according to claim 1, further comprising a step of extending a crack of the first brittle substrate in the thickness direction along a line. The at least one first crack line is a plurality of crack lines including a trigger crack line;
The step of extending the crack of the first brittle substrate in the thickness direction along the second trench line is performed by dividing the first brittle substrate along the trigger crack line. Item 3. A substrate cutting method according to Item 2.   The step of forming the second crack line is performed by displacing the blade edge on the second main surface of the first brittle substrate along the line where the second crack line is to be formed. The substrate cutting method according to claim 1, which is performed.   After the step of forming the first trench line, the first brittle substrate is second brittle so that the first trench line formed in the first brittle substrate is at least partially covered. The board | substrate cutting method of any one of Claims 1-4 further provided with the process of bonding a board | substrate.

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