KR20160062694A - Dividing method of brittle substrate - Google Patents

Abstract

(Challenge) Directly beneath it is a break along a trench line that has been formed into a crack that does not have cracks.
(Solution) A trench line TL extending through one point N2 on the surface SF1 of the brittle substrate 11 is formed so as to obtain a crackle state by moving the blade tip. The brittle substrate 11 is separated along the line BL intersecting the trench line TL at one point N2 so that the cross section SE exposed by the trench line TL is maintained in a cracked state . The surface roughness of the end face SE is increased. Next, the brittle substrate 11 is divided along the trench line TL.

Description

[0001] DIVIDING METHOD OF BRITTLE SUBSTRATE [0002]

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

In the production of electric devices such as flat display panels or solar panels, it is often necessary to separate 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 machining the substrate using a blade tip. As the end of the blade slides or rolls on the substrate, a trench due to plastic deformation is formed on the substrate, and a vertical crack is formed immediately below the trench. Thereafter, a stress imparting called a braking process is performed. By this, the vertical crack is completely advanced in the thickness direction, whereby the substrate is divided.

The process of dividing the substrate is performed relatively immediately after the process of forming the scribe line on the substrate. However, it has also been proposed to perform a step of machining the substrate between the step of forming the scribe line and the step of breaking.

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

Further, according to the technique of International Publication No. 2003/006391, for example, in a method of manufacturing a liquid crystal display panel, two glass substrates are bonded after a scribe line is formed. Thus, two brittle substrates can be simultaneously braked by one braking process.

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

According to the above conventional technique, the brittle substrate is processed after formation of the scribe line, and the braking process is performed by the subsequent stress application. This means that a vertical crack already exists along the entire scribe line at the time of processing the brittle substrate. Therefore, additional stretching in the thickness direction of the vertical cracks occurs unintentionally during processing, so that the brittle substrate, which should be integrated during processing, may be separated. Even when the substrate processing step is not carried out between the scribing line forming step and the substrate breaking step, it is usually necessary to carry or store the substrate after the scribing line forming step and before the breaking step of the substrate. The substrate may unintentionally be divided at the time.

In order to solve the above-described problems, the present inventor has developed an independent division technique. According to this technique, as a line defining the position where the brittle substrate is divided, first, a trench line having no crack is formed immediately under the line. By forming the trench line, the position at which the brittle substrate is divided is defined. Thereafter, if a state in which no crack is present immediately below the trench line is maintained, division along the trench line is unlikely to occur easily. By using this state, it is possible to prevent the brittle substrate from being unintentionally divided before the time when the brittle substrate should be divided, while stipulating in advance the position where the brittle substrate is divided.

As described above, the trench line is less susceptible to breakage as compared with a conventional scribe line. This is useful in the sense of preventing inadvertent division along the trench line, while in order to effect intentional division along the trench line, it is necessary to have a process that is particularly suited for generating a crack along the trench line do. The present inventors have already found that one such process can use a process of dividing a brittle substrate along a line intersecting a trench line. However, when the load applied to the edge of the blade becomes relatively small when forming the trench line, cracks along the trench line may not occur in the above-described processing. Reduction of the load may be required for the reason such as prevention of unintentional division more surely or longevity of the end of the blade. Therefore, in such a case, a treatment capable of generating a crack along the trench line is also required.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and an object of the present invention is to provide a method of manufacturing a semiconductor device, which is capable of performing a division along a trench line not having a crack immediately below the trench line, Method.

The brittle substrate cutting method has the following steps.

By creating a plastic deformation on the surface by pressing and moving the blade tip onto the surface of the brittle substrate, a trench line extending through one point on the surface is formed. The step of forming the trench line is carried out so as to obtain a crackle state immediately below the trench line in a state in which the brittle substrate is continuously connected in the direction intersecting the trench line.

By separating the brittle substrate along a line intersecting the trench line at one point on the surface of the brittle substrate, a cross-section in which the trench line is exposed is formed. The process of separating the brittle substrate is performed so that the crackle state is maintained.

The surface roughness of the cross section is increased. After the surface roughness of the cross section is increased, the brittle substrate is divided along the trench line. The step of dividing the brittle substrate includes a step of extending a crack along the trench line starting from a point by applying a stress to a portion where the trench line is exposed on a cross section.

According to the present invention, the surface roughness of the cross-section where the trench line is exposed is increased. As a result, cracks tend to occur starting from the point where the trench line is exposed on the end face. Therefore, it is possible to perform the division along the trench line which does not have a crack immediately below the trench line, even when the trench line is formed in the lowered state.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart schematically showing a method of dividing a brittle substrate according to Embodiment 1 of the present invention. FIG.
2 is a top view schematically showing one step of a brittle substrate cutting method according to Embodiment 1 of the present invention.
Fig. 3 is a schematic partial cross-sectional view taken along a line IIIA-IIIA of Fig. 2, which shows a trench line in a cracked state and a diagram (B) showing a comparative example thereof.
4 is a top view schematically showing one step of a brittle substrate cutting method according to Embodiment 1 of the present invention.
5 is a schematic partial side view of a section of a brittle substrate according to the view of arrow (V) in Fig.
6 is a cross-sectional view schematically showing one step of a brittle substrate cutting method according to Embodiment 1 of the present invention.
7 is a cross-sectional view schematically showing one step of a brittle substrate cutting method according to Embodiment 1 of the present invention.
Fig. 8 is a schematic partial side view according to the view of arrow VIII in Fig. 7;
9 is a cross-sectional view schematically showing one step of a brittle substrate cutting method according to Embodiment 1 of the present invention.
10 is a cross-sectional view schematically showing one step of a brittle substrate cutting method according to Embodiment 1 of the present invention.
11 is a side view (A) schematically showing a configuration of a scribing mechanism used in a brittle substrate cutting method according to Embodiment 1 of the present invention, and FIG. 11 (B) is the bottom view of the edge of the blade by visual field.
Fig. 12 is a bottom view of a blade edge according to a visual field corresponding to a side view (A) schematically showing a configuration of the scraping mechanism in the modified example of Fig. 11 and an arrow (XII) B).
13 is a top view schematically showing one step of a brittle substrate cutting method according to Embodiment 2 of the present invention.
14 is a top view schematically showing one step of a brittle substrate cutting method according to Embodiment 2 of the present invention.
15 is a side view schematically showing a configuration of a scribing mechanism used in a brittle substrate cutting method according to Embodiment 2 of the present invention.
Fig. 16 is a front view (A) schematically showing the configuration of the scribing wheel and pin in Fig. 15, and a partially enlarged view (B) of Fig. 16 (A).

Hereinafter, a method for separating a brittle substrate according to each embodiment of the present invention will be described with reference to the drawings. In the following drawings, the same reference numerals are assigned to the same or corresponding parts, and the description thereof is not repeated.

(Embodiment 1)

Fig. 1 is a flow chart schematically showing a method of dividing a glass substrate 11 (brittle substrate) in the present embodiment. Fig. 2 is a top view schematically showing a state immediately after step S20 (Fig. 1).

First, a glass substrate 11 is prepared (Fig. 1: step S10). The glass substrate 11 has an upper surface SF1 (surface) and a lower surface that is the opposite surface. In detail, as will be described later, a scribing mechanism having a blade tip is prepared.

Next, the edge of the blade is moved while being pressed on the upper surface SF1 of the glass substrate 11. As a result, plastic deformation occurs on the upper surface SF1. As a result, a trench line TL extending from the point N1 to the point N3 via the point N2 (one point) is formed on the upper surface SF1 (Fig. 1: step S20). When the trench line TL is formed, the blade edge moves on the point N2 in the scribe direction DL (one direction). The points N1 to N3 indicate positions on the upper surface SF1.

The above-described process of forming the trench line TL is repeated as necessary, so that a desired number of trench lines TL can be formed. FIG. 2 illustrates a case where three trench lines TL are formed.

3A, the process of forming the trench line TL is performed in a direction (DC) in which the glass substrate 11 intersects with the trench line TL immediately below the trench line TL So that a state in which they are continuously connected (called a crackle state) is obtained.

3 (B) shows the trench line TL which is not in a crackle state. In this state, the glass substrate 11 is tilted by a crack line CL extending along the trench line TL immediately below the trench line TL in the direction (DC ). A conventional typical scribe line formed for dividing a glass substrate is accompanied by a crack line CL and is not formed in a crackle state.

Next, the glass substrate 11 is separated along the line BL intersecting the trench line TL at the point N2 on the upper surface SF1 of the glass substrate 11. This separation can be carried out, for example, by the formation of a conventional scribe line along the line BL, followed by a typical braking process.

Referring to FIG. 4, the separation SE exposes the trench line TL (FIG. 1: step S30). The normal direction (normal vector) DN of the cross section SE at the point where the trench line TL is exposed has a component in the scribe direction DL (Fig. 2). The normal direction DN and the scribe direction DL are preferably substantially the same.

Referring to Fig. 5, the process of separating the glass substrate 11 is carried out so that the cracked state is maintained. In order to do so, the load applied to the blade tip at the time of forming the above-described trench line TL may be sufficient to cause plastic deformation at the top surface SF1, but not to excessively increase.

Next, the surface roughness of the end face SE is increased. This step can be carried out by subjecting at least the trench line TL of the cross section SE to a mechanical exposure accompanied by minute crushing. Specifically, the trench line TL of the cross section SE TL) is exposed. This grinding can be carried out by using a tool such as, for example, a line or shaft grindstone.

Next, the glass substrate 11 is divided along the trench line TL (Fig. 1: step S40). For this purpose, a crack is caused to extend along the trench line TL starting from this point by a breaking process in which the trench line TL stresses the exposed portion on the end face SE. The braking process can be performed a plurality of times in accordance with the number of trench lines (TL). Hereinafter, the details of the preferred braking process will be described.

6, a glass substrate 11 (Fig. 2) on which a trench line TL is formed is arranged so that the top surface SF1 of the glass substrate 11 faces the table 80 via the rug 81, Is placed on the table (80) through the opening (81). The rug 81 is made of a material that is more easily deformed than the materials of the glass substrate 11 and the table 80.

Referring to Figs. 7 and 8, a brake bar 85 is prepared. As shown in Fig. 8, the brake bar 85 preferably has a protruding shape so as to locally pressurize the surface of the glass substrate 11, and has a substantially V-shaped shape in Fig. As shown in Fig. 7, this projecting portion extends in a straight line.

Next, the brake bar 85 is brought into contact with a part of the lower surface SF2 of the glass substrate 11. This contact portion is away from the end face SE of the glass substrate 11. [

Next, as shown by the arrow CT1, the contact portion expands along the trench line TL and approaches the end face SE. The break bar 85 is brought into contact with the portion opposed to the trench line TL on the lower surface SF2 and also from the end surface SE by the extension of the contact portion following the above- A state in which it is separated occurs.

9, the contact portion reaches the end face SE of the glass substrate 11, as indicated by the arrow CT2. As a result, stress is applied to the section SE. As a result, a crack occurs starting from the point where the trench line TL is exposed on the end face SE (Fig. 5). This crack is extended along the trench line TL (see arrow PR in Fig. 10).

By the breaking process described above, the glass substrate 11 is divided.

11 (A) and 11 (B), a description will now be given of a scribing mechanism 50 preferable for use in the present embodiment. The scribing mechanism 50 scribes the glass substrate 11 by moving relative to the glass substrate 11 by being mounted on a scribe head (not shown). The scribing mechanism 50 has a blade tip 51 and a shank 52. The blade tip 51 is held by the shank 52.

The blade tip 51 has a plurality of surfaces surrounding a top surface SD1 (first surface) and a top surface SD1. These plural surfaces include a side surface SD2 (second surface) and a side surface SD3 (third surface). The ceiling surface SD1 and the side surfaces SD2 and SD3 face each other in directions different from each other and are adjacent to each other. The blade tip 51 has a vertex at which the top face SD1 and the side faces SD2 and SD3 join together and forms the protrusion PP of the blade edge 51 by the vertex. The side faces SD2 and SD3 form a ridge constituting the side portion PS of the blade edge 51. [ The side portion PS extends linearly from the projection PP. Further, the side portion PS has a convex shape extending in a line on the ridgeline point as described above.

The blade tip 51 is preferably a diamond point. That is, the blade tip 51 is preferably made of diamond. In this case, the hardness can be increased and the surface roughness can be easily reduced. More preferably, the blade tip 51 is made of single crystal diamond. More preferably, the crystal plane SD1 is a {001} plane and each of side faces SD2 and SD3 is a {111} plane. In this case, the side faces SD2 and SD3 are crystal planes which have different directions but are equivalent to each other in terms of crystallography.

Further, a diamond other than a single crystal may be used. For example, a polycrystalline diamond synthesized by a CVD (Chemical Vapor Deposition) method may be used. Alternatively, polycrystalline diamond sintered without containing a binder such as iron family elements, or sintered diamond obtained by bonding diamond particles with a binding material such as an iron family element from fine graphite or graphitic carbon may be used.

The shank 52 extends along the axial direction AX. The blade tip 51 is preferably mounted on the shank 52 so that the normal direction of the surface SD1 substantially follows the axial direction AX.

When the scribing mechanism 50 is applied to this embodiment, the pressurized blade end 51 is slid in the advancing direction DA on the upper surface SF1. The advancing direction DA is a direction in which the direction extending from the projection PP along the side portion PS is projected on the upper surface SF1 and the axial direction AX is projected on the upper surface SF1 Direction. In addition, when the traveling direction DB opposite to the traveling direction DA is used, cracks along the trench line TL do not occur in the present embodiment. This direction dependence is presumed to be due to the distribution of the stress in the glass substrate 11 caused by the formation of the trench line TL.

Referring to Figs. 12 (A) and 12 (B), as a modification, a scribing mechanism 50v may be used. The blade tip 51v of the scribing mechanism 50v has a conical shape with a vertex and a conical surface SC. The projecting portion PPv of the blade tip 51v is constituted by apices. The side portion PSv of the blade tip is formed along an imaginary line (broken line in (B) of Fig. 12) extending from the apex to the conical surface SC. As a result, the side portion PSv has a convex shape extending in a line.

According to the present embodiment, the surface roughness of the end surface SE (FIG. 5) where the trench line TL is exposed is increased. As a result, cracks tend to occur starting from the point where the trench line TL is exposed on the end face SE as a starting point. Therefore, it is possible to perform the division along the trench line TL (FIG. 3A) which does not have a crack immediately below the trench line TL, even when the trench line TL is formed in the lowered state.

(Embodiment 2)

Referring to Fig. 13, a trench line TL is formed on the upper surface SF1 of the glass substrate 11 in substantially the same manner as in Embodiment 1 (Fig. 2). However, the posture of the scribe mechanism or the edge of the blade which is preferably used for forming the trench line TL is different between the first and second embodiments. The details of this point will be described later.

Next, as in Embodiment 1, the glass substrate 11 is separated along the line BL.

Referring to Fig. 14, by the separation, a cross-section SE in which the trench line TL is exposed is formed. The normal direction DN of the section SE at the point where the trench line TL is exposed has components in the direction opposite to the scribe direction DL (Fig. 13) in the present embodiment. The normal direction DN and the scribe direction DL are preferably substantially opposite.

Next, a process substantially similar to that of Embodiment 1 is carried out. That is, the surface roughness of the cross section SE is increased, and the glass substrate 11 is then divided along the trench line TL.

Referring to Fig. 15, a description will now be given of a scribe mechanism 50R preferable for use in the present embodiment. Fig. The scribing mechanism 50R has a scribing wheel 51R, a holder 52R, and a pin 53. [ The scribing wheel 51R has a substantially disc-shaped shape, and its diameter is typically on the order of several millimeters. The scraping wheel 51R is rotatably held around the rotating shaft RX via a pin 53 to the holder 52R.

The scribing wheel 51R has an outer peripheral portion PF formed with a blade edge. The outer peripheral portion PF extends in an annular shape around the rotation axis RX. As shown in Fig. 16 (A), the outer peripheral portion PF is formed in a ridge line at the naked eye level, thereby constituting a blade edge composed of a ridge line and an inclined plane. On the other hand, at the microscopic level, the ridgeline of the outer peripheral portion PF at the portion (actually below the two-point chain line in Fig. 16B) actually operated by the penetration of the scribing wheel 51R into the glass substrate 11 is fine And has a surface shape (MS). It is preferable that the surface shape MS has a curved shape having a finite curvature radius when viewed from the front (Fig. 16 (B)).

The scribing wheel 51R is formed using a hard material such as a hard metal, sintered diamond, polycrystalline diamond, or single crystal diamond. From the viewpoint of reducing the surface roughness of the above-mentioned ridgelines and slopes, the entire scribing wheel 51R may be made of single crystal diamond.

To form the trench line TL (Fig. 15) using the scribing mechanism 50R, the blade end of the scribing mechanism 50R is placed on the upper surface SF1 of the glass substrate 11, (See Fig. 15). In other words, the blade tip is turned (arrow RT) on the upper surface SF1 of the glass substrate 11.

At this time, the load F applied to the blade edge has a vertical component Fp parallel to the thickness direction DT of the glass substrate 11 and an in-plane component Fi parallel to the upper surface SF1. The advancing direction DB of the scribing wheel 51R by the transmission of the scribing wheel 51R is the same as the direction of the in-plane component Fi. In other words, the scribe direction DL (Fig. 13) is the same as the direction of the in-plane component Fi.

The same effects as those of the first embodiment can be obtained also by this embodiment. According to the present embodiment, the scribing wheel 51R can be used for forming the trench line TL. Also, when the scribing wheel 51R is applied to the first embodiment, a crack along the trench line TL is less likely to occur as compared with the present embodiment.

Also, a scribing mechanism 50 or 50v may be used instead of the scribing mechanism 50R. In this case, contrary to the first embodiment, it is preferable that not the advancing direction DA but the advancing direction DB which is the opposite direction is used. As a result, cracks along the trench line TL are more likely to occur.

The brittle substrate cutting method according to each of the above embodiments is particularly preferably applied to a glass substrate, but the brittle substrate may be made of a material other than glass. For example, ceramics, silicon, compound semiconductors, sapphire, or quartz may be used as materials other than glass.

N2 points (one point)
SF1 upper surface (surface)
SF2
TL trench line
11 Glass substrate (brittle substrate)
50, 50R, 50v scribing mechanism
51, 51v blade tip
51R scriing wheel
85 Brake bar

Claims (7)

Forming a trench line extending through a point on said surface by causing plastic deformation on said surface by pressing and moving said blade tip onto the surface of said brittle substrate; The forming step is carried out so as to obtain a crackle state in a state in which the brittle substrate is continuously connected in the direction crossing the trench line immediately below the trench line,
And separating the brittle substrate along a line intersecting the trench line at the one point on the surface of the brittle substrate to form a cross-section in which the trench line is exposed, The process is performed to maintain the crackle state, and further,
A step of increasing the surface roughness of the cross section,
And a step of dividing the brittle substrate along the trench line after the step of increasing the surface roughness of the cross section, wherein the step of dividing the brittle substrate includes a step of compressing stress at a point where the trench line is exposed on the cross section Thereby extending a crack along the trench line from the point as a starting point. The method according to claim 1,
Wherein the step of increasing the surface roughness of the cross section includes a step of performing mechanical processing on the cross section. 3. The method of claim 2,
Wherein the step of mechanically machining comprises a step of grinding the cross section. 4. The method according to any one of claims 1 to 3,
In the step of forming the trench line, the end of the blade moves the one point in one direction,
Wherein a normal direction of the cross section at a point where the trench line is exposed has a component in the one direction. 5. The method of claim 4,
Wherein the step of forming the trench line comprises the step of sliding the blade tip on the surface of the brittle substrate. 4. The method according to any one of claims 1 to 3,
In the step of forming the trench line, the end of the blade moves the one point in one direction,
Wherein a normal direction of the section at a point where the trench line is exposed has a component opposite to the one direction. The method according to claim 6,
Wherein the step of forming the trench line comprises the step of rolling the blade tip on the surface of the brittle substrate.

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