HK1155691A - Cutter wheel, scribing method and cutting method for fragile material substrate using the cutter wheel, and method of manufacturing cutter wheel - Google Patents

Description

Cutter wheel, scribing method and dividing method for brittle material substrate using same, and method for manufacturing cutter wheel

The present invention is filed in filed application No. 200580003903.4 filed on 2005, 02/01, entitled "cutter wheel, method for scribing and dividing brittle material substrate using the same, and method for manufacturing cutter wheel

Technical Field

The present invention relates to a cutter wheel, and more particularly, to a cutter wheel for scribing a brittle material substrate, in which a V-shaped ridge portion is formed as a blade along a circumferential portion of a disk-shaped wheel, and a plurality of protrusions having a predetermined shape are formed at substantially equal intervals on the ridge portion, and a method for scribing and dividing a brittle material substrate using the cutter wheel, and a method for manufacturing the cutter wheel.

Background

A liquid crystal display panel, which is one type of flat panel display panel (hereinafter referred to as FPD), is configured by bonding 2 glass substrates and injecting liquid crystal into a gap between the substrates. In the case of a reflective substrate in a projection substrate called LCOS, a pair of brittle substrates obtained by bonding a quartz substrate and a semiconductor wafer is used. A bonded substrate obtained by bonding the brittle substrates as described above is generally divided into unit substrates of predetermined sizes by forming scribe lines on the surface of the bonded substrate as a mother substrate and then breaking the substrate along the formed scribe lines.

In the present specification, forming a scribe line is referred to as "dicing", and separating a substrate piece along the formed scribe line is referred to as "dividing". In the present invention, the property of the cutter wheel that "a vertical crack is formed relatively deep in the thickness of the glass substrate in the vertical direction from the surface of the glass substrate" is referred to as "permeability". In the case of using a cutter wheel having high permeability, which will be described later, the substrate can be in a "divided" state only by the "dicing" step.

Patent documents 1 and 2 disclose the following configurations: a mother substrate is bonded by a cutter wheel pair to form a scribe line, and then the glass substrate is divided into unit glass substrates of a desired size along the formed scribe line.

(patent document 1) Japanese patent application laid-open No. 11-116260

(patent document 2) Japanese patent No.3,074,143

Fig. 17 is a front view of a known scribing apparatus used for the scribing operation.

A conventional scribing method will be described with reference to fig. 17. In fig. 17, the left-right direction is defined as the X direction, and the direction perpendicular to the paper surface is defined as the Y direction.

As shown in fig. 17, the scribing apparatus 100 includes: a table 28 for holding the glass substrate G by a vacuum suction mechanism and horizontally rotating; a pair of guide rails 21, 21 parallel to each other and supporting the table 28 so as to be movable in the Y direction; a ball screw 22 for moving the table 28 along the guide rails 21, 21; a guide bar 23 which is erected above the table 28 in the X direction; a scribe head 1 provided on the guide bar 23 to be slidable in the X direction and applying a cutting pressure to a cutter wheel 10 described later; a motor 24 for sliding the scribing head 1 along the guide bar 23; a cutter wheel holder 4 which is provided at the lower end of the scribing head 1 in a manner of being capable of lifting and swinging; a cutter wheel 10 rotatably mounted on the lower end of the cutter wheel holder 4; and a pair of CCD cameras 25 disposed above the guide bar 23 for recognizing a reference mark of the glass substrate G formed on the stage 28.

Fig. 18 and 19 are views for explaining the dividing step of the glass substrate, that is, the step of forming the scribe line on the surface of the glass substrate and the step of dividing the glass substrate along the formed scribe line.

Referring to fig. 18 and 19, two examples of the dividing step of the glass substrate will be described. In the following description, a glass substrate G used as a laminated glass for a liquid crystal panel is exemplified, and one glass substrate is an a-side glass substrate and the other is a B-side glass substrate.

In example 1, (1) first, as shown in fig. 18(a), a glass substrate G is placed on a scribing table of a scribing apparatus with the a-side glass substrate being on the upper side, and a scribe line Sa is formed on the a-side glass substrate by scribing with a cutter wheel 10.

(2) Next, the glass substrate G is turned upside down and conveyed to a breaking apparatus. Then, as shown in fig. 18(B), the breaking device presses the dividing bar 3 against the B-side glass substrate of the glass substrate G placed on the pad 4 along the line facing the scribe line Sa. Accordingly, the lower a-side glass substrate is upwardly cracked from the scribe line Sa, and the a-side glass substrate is cracked along the scribe line Sa.

(3) Next, the glass substrate G is conveyed to a scribing table of a scribing apparatus. Then, with this scribing apparatus, as shown in fig. 18(c), a scribe line Sb is formed by scribing the B-side glass substrate with the cutter wheel 10.

(4) Then, the glass substrate G is turned upside down and conveyed to a breaking apparatus. Then, as shown in fig. 18(d), the dividing bar 3 is pressed against the a-side glass substrate of the glass substrate G mounted on the pad 4 along a line facing the scribe line Sb. Accordingly, the lower B-side glass substrate is cracked upward from the scribe line Sb, and the B-side glass substrate is cracked along the scribe line Sb.

In the present invention, the division method formed by the above steps is called an SBSB method (S denotes scribe lines, and B denotes splits).

In example 2, (1) first, as shown in fig. 19(a), the a-side glass substrate is placed on the scribing table of the scribing apparatus with the a-side glass substrate on the upper side, and the scribing Sa is formed on the a-side glass substrate by scribing with the cutter wheel 10.

(2) Next, the glass substrate G is turned upside down, and the glass substrate G is placed on a scribing table, and a scribe line Sb is formed on the B-side glass substrate by scribing with a cutter wheel 10 (fig. 19 (B)).

(3) Then, the glass substrate G is conveyed to a breaking apparatus. Then, as shown in fig. 19(c), the breaking apparatus presses the dividing bar 3 against the B-side glass substrate of the glass substrate G placed on the pad 4 along the line facing the scribe line Sa. Accordingly, the lower a-side glass substrate is upwardly cracked from the scribe line Sa, and the a-side glass substrate is cracked along the scribe line Sa.

(4) Next, the glass substrate G is turned upside down and placed on the pad 4 of the breaking device as shown in fig. 19 (d). Then, the dividing bar 3 is pressed against the a-side glass substrate of the glass substrate G along the line of the opposing scribe line Sb. Accordingly, the lower B-side glass substrate is cracked upward from the scribe line Sb, and the B-side glass substrate is cracked along the scribe line Sb.

In the present invention, the division scheme formed by the above steps is referred to as an SSBB scheme.

By performing the steps (1) to (4) of the above two examples, the glass substrate G is divided into 2 pieces along the scribe lines at desired positions.

In addition, one of the conditions required for dividing the glass substrate is a rib-shaped blade surface which generates a so-called "rib mark" by intermittently progressing a vertical crack during scribing.

When a pressing load (hereinafter, referred to as "cutting pressure") of a cutter wheel against the glass substrate during scribing is set to an appropriate cutting area where a good scribe line can be formed, a rib mark can be generated. However, when scribing is performed with an increased cutting pressure, the occurrence of so-called chipping (chipping) or an increase in horizontal cracks is conspicuously observed on the surface of the glass substrate G. If the cutting pressure is set to a small suitable cutting area, it is difficult to set the cutting pressure, and if the lower limit value of the cutting pressure is high, chipping or horizontal cracking is likely to occur. As described above, it is preferable that the cutting pressure has a wide suitable cutting area and a low lower limit.

Disclosure of Invention

Unlike the case where the scribe line is formed only in one direction on the glass substrate by using the conventional scribing apparatus, when the scribe line is performed vertically and horizontally so that a plurality of scribe lines intersect to form an intersection, a phenomenon called cross-over may occur. This phenomenon is a phenomenon in which, as shown in fig. 20, when the cutter wheel 20 attempts to form the scribe lines L4 to L6 by the initially formed scribe lines L1 to L3, the scribe lines L4 to L6 to be formed later are locally not formed near the intersection point of these scribe lines.

If such a cross point jump occurs in the glass substrate, when the glass substrate is to be divided by the breaking device, the glass substrate cannot be divided by scribing, resulting in a large number of defective products and a significant reduction in production efficiency.

The reason for the cross point jump is as follows. That is, when the scribe line is formed first, internal stress exists inside the vicinity of the glass surface on both sides across the scribe line. Next, when the cutter wheel passes through the scribe line formed first, the force required for scribing the cutter wheel in the direction perpendicular to the glass substrate surface is reduced by the internal stress in the vicinity thereof, and as a result, the scribe line to be formed later cannot be formed in the vicinity of the intersection.

On the other hand, when the scribing line is formed by using the cutter wheel, there are disadvantages that a deep cut (vertical crack) cannot be obtained on the surface of the glass substrate, and the scribing line easily slips on the surface of the glass substrate and cannot form an original normal scribing line.

Fig. 1 and 2 are schematic views (including partially enlarged views) illustrating the blade shape of a conventional high permeability cutter wheel and the blade shape of the present invention.

Patent document 2 discloses a cutter wheel 20 for scribing a brittle material substrate, as shown in fig. 1 and 2, in which a V-shaped ridge portion is formed as a blade 2 along a circumferential portion of a disk wheel, and a plurality of projections j of a predetermined shape are formed by cutting grooves 10b at substantially equal intervals in the ridge portion. By forming a scribe line using the cutter wheel 20, a relatively deep vertical crack can be formed in the thickness of the glass substrate in the vertical direction from the surface of the glass substrate.

In the case of using the cutter wheel 20 having high permeability as described above, the above-described crossing point jump or slipping on the surface of the glass substrate during scribing can be suppressed, and the breaking step after scribing can be simplified. In some cases, the SBSB method cleavage step shown in fig. 18(b) and 18(d) or the SSBB method cleavage step shown in fig. 19(c) and 19(d) may be omitted.

In recent years, glass substrates used for liquid crystal display panels and the like have been increasingly used for mobile terminals such as cellular phones, and therefore, in view of ease of carrying, there has been an increasing demand for weight reduction, and therefore, the thickness of the glass substrate has been increasingly thinner, and in order to compensate for the reduction in rigidity caused by the thinner glass substrate, the material of the glass substrate has been improved, and as a result, even when a cutter wheel 20 having high permeability is used, it has been increasingly difficult to form a good scribe line on the glass substrate. In other words, if scribing is performed with the same load as a glass substrate having a conventional thickness, the glass substrate is easily broken. In order to prevent breakage of the glass substrate, it is difficult to form a rib mark on the surface of the glass substrate by scribing with a low load, and it is difficult to divide the glass substrate into unit substrates.

In view of the above-mentioned problems of the prior art, an object of the present invention is to provide: a cutter wheel capable of stably forming a high-precision scribing line even when the thickness of a brittle material substrate is thin when the brittle material substrate is divided, a scribing method for the brittle material substrate using the cutter wheel, and a manufacturing method for the cutter wheel.

The inventors of the present invention have intensively studied to find that: the present invention has been accomplished by providing a cutter wheel capable of suppressing the occurrence of crossing point jump and stably forming a scribe line with high accuracy even when the thickness of a brittle material substrate is small, and a method for scribing a brittle material substrate using the cutter wheel.

That is, according to the present invention, there is provided a cutter wheel for scribing a brittle material substrate, comprising a disk-shaped wheel having a circumferential edge portion formed with a V-shaped ridge line portion as a blade edge, and a plurality of projections of a predetermined shape formed at substantially equal intervals on the ridge line portion, wherein:

the outer diameter of the cutter wheel is 1.0-2.5mm, the protrusions are formed at intervals of 8-35 μm around the ridge portion, the height of the protrusions is 0.5-6.0 μm, and the angle of the blade is 85-140 deg.

According to another aspect of the present invention, there is provided a scribing method for a brittle material substrate, comprising pressing and rotating a cutter wheel against the brittle material substrate to form a scribe line on a surface of the brittle material substrate; the knife wheel is characterized in that a V-shaped ridge line part is formed along the circumference part of the disc-shaped wheel to be used as a knife edge, and a plurality of bulges are formed on the ridge line part at approximately equal intervals; the method is characterized in that:

when scribing a brittle material substrate, a cutter wheel having an outer diameter of 1.0 to 2.5mm, projections formed at a pitch of 8 to 35 μm over the entire circumference of the ridge line portion, a height of 0.5 to 6.0 μm, and an angle of a blade edge of 85 to 140 DEG is used.

According to another aspect of the present invention, there is provided a method for dividing a brittle material substrate, comprising: a scribe line is formed on a brittle material substrate using a cutter wheel, and then a load is applied along the formed scribe line to perform breaking.

In the method for dividing a brittle material substrate according to the present invention, the breaking step can be omitted, and the brittle material substrate can be divided along the scribe line by forming the scribe line only on the brittle material substrate, and thus the brittle material substrate can be separated.

By using the cutter wheel of the invention to perform scribing, the generation of crossing point jump can be inhibited, and the scribing with high precision can be stably formed even if the thickness of the brittle material substrate is thin.

The method for dividing a brittle material substrate according to the present invention can suppress the occurrence of crossing point jump, and can stably form a scribe line with high accuracy even when the brittle material substrate has a small thickness.

A brittle material substrate having a thickness of 0.4mm to 0.7mm is scribed by applying a load of 0.03 to 0.19MPa to the blade of a cutter wheel, so that a highly accurate scribe line can be stably formed with a relatively small cutting pressure.

Examples of the brittle material substrate to be divided include alkali-free glass, synthetic quartz glass, and glass substrates for TFT liquid crystal panels.

In the method for dividing a brittle material substrate according to the present invention, the strength of the divided brittle material substrate can be improved by using the cutter wheel according to the present invention. In the present invention, the strength of the brittle material substrate means a bending strength in a 4-point bending test defined in JIS R3420.

Drawings

Fig. 1 is a front view of the cutter wheel of the present invention and a conventional cutter wheel as viewed from a direction orthogonal to the rotation axis thereof.

Fig. 2 is a side view of fig. 1.

Fig. 3(a) and 3(b) are views illustrating a liquid crystal panel dividing line using the cutter wheel of the present invention.

Fig. 4 is a graph showing the evaluation of the separability of the cutter wheel of experiment 1 with respect to the glass substrate.

Fig. 5 is a graph showing the evaluation of the separability of the cutter wheel of experiment 2 with respect to the glass substrate.

Fig. 6 is a diagram for explaining the cause of the corner defect in experiment 2.

Fig. 7 is a diagram for explaining the cause of the squeeze crack in experiment 2.

Fig. 8 is a graph showing the evaluation of the separability of the cutter wheel of experiment 3 with respect to the glass substrate.

Fig. 9 shows a glass bending strength test apparatus used for the glass bending strength test in experiment 4.

Fig. 10 is a graph plotting the results of the glass bending strength test obtained for each sample cutter wheel used in experiment 4 on weber probability paper.

Fig. 11 is a graph calculated by analyzing each fracture surface of the sample substrate fractured at the end of the glass bending strength test in experiment 4 and correlating the data with the sample cutter wheel as the occurrence rate of the fracture pattern.

Fig. 12 is a graph plotting the results of the glass bending strength test obtained for each sample cutter wheel used in experiment 4 on weber probability paper.

Fig. 13 is a graph calculated by analyzing each fracture surface of the sample substrate fractured at the end of the glass bending strength test in experiment 4 and correlating the data with the sample cutter wheel as the occurrence rate of the fracture pattern.

Fig. 14 is a graph plotting the results of the glass bending strength test obtained for each sample cutter wheel used in experiment 4 on weber probability paper.

Fig. 15 is a graph calculated by analyzing each fracture surface of the sample substrate fractured at the end of the glass bending strength test in experiment 4 and correlating the data with the sample cutter wheel as the occurrence rate of the fracture pattern.

Fig. 16 is a front view of the cutter wheel with the front end side of the cutting edge enlarged, illustrating an example of a two-stage polishing method for explaining the method of manufacturing the cutter wheel according to the present invention.

Fig. 17 is a front view of a conventional scribing apparatus used for scribing.

Fig. 18(a) - (d) are diagrams for explaining the steps of forming a scribe line on the surface of a glass substrate by the conventional SBSB method and dividing the glass substrate along the formed scribe line.

Fig. 19(a) - (d) are used to illustrate the steps of forming a scribe line on the surface of a glass substrate by a conventional SSBB method and dividing the glass substrate along the formed scribe line.

Fig. 20 is a perspective view for explaining a phenomenon of crossing point jump which occurs when a cross-hatch is performed.

1: marking head 2: blade point

3: the dividing rod 10: knife flywheel (conventional)

20: cutter wheel (conventional) 20 a: edge line part

20 b: groove 40: knife flywheel (the invention)

40 a: ridge line portion 40 b: trough

100: marking device

Detailed Description

To further explain the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description of the embodiments, structures, features and effects according to the present invention will be made with reference to the accompanying drawings and preferred embodiments.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The brittle material substrate of the present invention is not particularly limited in form, material, use, and size, and may be a substrate made of a single plate, a bonded substrate made by bonding 2 or more single plates, or a thin film or a semiconductor material may be attached to the surface or the inside of such a substrate.

The brittle material substrate of the present invention may be made of glass, ceramic, silicon, sapphire, etc., and its application may be a panel for flat panel display such as a liquid crystal display panel, a plasma display panel, an organic EL display panel, etc.

The "number of divided projections" of the present invention is the number of projections represented by the number of equally divided circumferences, in which a plurality of projections of a predetermined shape are formed at appropriate intervals in a portion where a ridge line portion of a V shape is formed along the circumference of a cutter wheel and serves as a blade.

In the following embodiments, examples relating to the shape of the cutter wheel according to the present invention are shown, but the cutter wheel according to the present invention is not limited to these examples.

Referring to fig. 1 and 2, an embodiment of a cutter wheel 40 according to the present invention is illustrated.

Fig. 1 is a front view as viewed from a direction orthogonal to the rotational axis of the cutter wheel 40, and fig. 2 is a side view of fig. 1.

The cutter wheel 40 is a cutter wheel that can be mounted on the scribing head 1 of the conventional scribing apparatus 100 described with reference to fig. 17.

As shown in fig. 1, the cutter wheel 40 is a disk-shaped wheel having an outer diameter Φ and a wheel thickness W, and has a cutter edge 2 having a cutter edge angle α formed on the outer periphery of the wheel.

As shown in fig. 1 and 2, the cutter wheel 40 has a ridge 40a forming the blade 2. That is, in this example, as shown in the partially enlarged view of fig. 2, a U-shaped or V-shaped groove 40b is formed. The grooves 40b are formed by cutting at each pitch P from the flat ridge line portion 40a to a depth h. By forming these grooves 40b, projections j (corresponding to ridge portions 40a) having a height h are formed at each pitch P. The grooves 40b are of a micron size that cannot be seen with the naked eye.

Fig. 3 is a diagram illustrating liquid crystal panel dividing lines 30A and 30B using the cutter wheel 40 of the present invention. Fig. 3(a) shows a line 30A for implementing the SBSB system shown in fig. 18, and fig. 3(B) shows a line 30B for implementing the SSBB system shown in fig. 19.

As shown in fig. 3, the liquid crystal panel dividing lines 30A and 30B include: liquid crystal panel dividing devices 32 and 34, a chamfering device 36, and transfer robots 31, 33, and 35 disposed between these devices.

As shown in fig. 3(a), the liquid crystal panel dividing device 32 includes: scribing devices S (S1, S2) and breaking devices B (B1, B2) for implementing the SBSB system, inverting conveyance robots R1 and R2 for inverting and conveying the upper and lower surfaces of a glass substrate G, and a conveyance robot M for conveying the glass substrate G without inverting the glass substrate G are provided.

As shown in fig. 3(b), the liquid crystal panel dividing device 34 includes: the scribing apparatus S (S1, S2) and the breaking apparatus B (B1, B2) which implement the SSBB system are configured by the turning conveyance robots R1 and R2 and the conveyance robot M for conveying the glass substrate G, as in fig. 3 a.

Each scribing apparatus S1, S2 has the same configuration as the scribing apparatus 100 of fig. 17, and the cutter wheel 40 is attached to the cutter wheel holder 4 instead of the cutter wheel 10 in fig. 17.

Experiments to evaluate the cutting characteristics of the cutter wheel of the present invention with respect to the glass substrate and the results thereof will be described with reference to fig. 4 to 15.

(experiment 1)

In experiment 1, when the glass substrate was divided by using the cutter wheel 40, the relationship between the depth of the rib mark formed by the blade 2 of the cutter wheel 40 and the cutting region (range where the cutting can be performed) of the cutting pressure was measured. The "rib mark" is a visual indication of whether or not a good scribe line is formed on a rib-like fractured surface generated by the intermittent progress of cracking.

The division conditions are shown below.

Alkali-free glass of object glass substrate (glass veneer with thickness of 0.4 mm)

The material of the cutter wheel is as follows: sintered diamond

Outer diameter phi: 2.0mm

Thickness W: 0.65mm

The shaft aperture is as follows: 0.8mm

Pitch P of protrusions: 8.7-34.1 μm (circumference is equalized)

Divided into 230-900)

Height h of the protrusion: 0.5-3 μm

Blade angle α: 90-115 degree

Marking device Mitsu Diamond Industrial Co Ltd MS model

Setting conditions of the glass substrate cutting depth: 0.1mm

Scribing speed: 300mm/sec

Cutting pressure: 0.03-0.22MPa

(the cutting pressure means the pressure applied when forming the scribe line

Pressure on the cutter wheel. )

Table 1 shows the characteristics of the blade edge of the cutter wheel used as a sample.

[ TABLE 1 ]

Referring to fig. 4, the separability of the glass substrate by the cutter wheel of experiment 1 was evaluated. That is, the relationship between the depth of the rib mark (formed by the edge of the cutter wheel) and the cutting area of the cutting pressure is measured in accordance with the cutting edge.

As can be seen from fig. 4, the blades of samples nos. 7, 8, 10 and 11, particularly the blades of nos. 7, 10 and 11, formed relatively deep rib marks and obtained wide cutting regions for cutting pressure.

(experiment 2)

In experiment 2, the glass substrate was cross-scribed using a cutter wheel, and the end surface condition of the intersection of the cross-scribed glass substrate was observed. The conditions for division and the cutter wheel 40 used as a sample are shown in table 1 in the same manner as in experiment 1.

FIG. 5 shows the result of evaluation of the separability of experiment 2. That is, the relationship between the end surface condition of the intersection of the glass substrates subjected to the cross scribing and the cutting region of the cutting pressure was measured for the blade of each of the samples 1 to 11.

In fig. 5, it is shown that "<" > is a particularly good state, ". smallcircle" is a good state, ". DELTA" is a low-damaged state, ". X" is a high-damaged state, and "-" is a non-cuttable state.

Fig. 6 and 7 are views for explaining damage to a glass substrate such as "chipping" or "chipping", which will be described later, and each upper view shows a cross section of a scribe line L4 formed from a lower scribe line L1 shown in each figure, and each lower view shows each plane.

The "unfilled corner" in the examination section in fig. 5 means, as shown in fig. 6: when the cutter wheel C is pressed against and rotated on the glass substrate and the side forming the scribe line L4 advances in the direction of the arrow in the figure and reaches the existing scribe line L1, the scribe line L1 in the half-divided state (the state where the vertical crack K reaches about 90% of the thickness of the glass substrate G) is divided in the oblique direction in the vicinity of the back surface of the glass substrate G, and a defect such as γ in fig. 6 occurs.

The term "squeeze crack" as shown in FIG. 7 means: the cutter wheel C is pressed against and rotated on the glass substrate, and the edge of the glass substrate is advanced in the arrow direction of the figure to form a scribe line L4, and as shown in fig. 20, the glass substrate G in a half-divided state (a state where the vertical crack K is about 90% of the thickness of the glass substrate G) is pushed against each other just before the existing scribe lines L1-L3 (only the scribe line L1 is shown in fig. 7), and a small notch is formed in each end surface portion, and a defect shown by β in fig. 7 is generated.

In experiment 2, as shown in fig. 5, the blade tips of samples nos. 2, 3, 5, 6, 9, 10 and 11, particularly the blade tips of samples nos. 3, 5, 6 and 10, obtained good intersections in a relatively wide cutting region with respect to the cutting pressure.

From experiments 1 and 2, it is known that: if used: the outer diameter of the wheel is 1.0-2.5mm, the projections are formed at 8-35 μm on the whole circumference of the ridge line part, the height of the projections is 0.5-6.0 μm, and the angle of the blade is 90-115 degrees, so that the occurrence of defects such as unfilled corners and squeezing cracks can be suppressed at the intersection point and the end face, and the strength of the end face of the divided glass substrate G is improved. As a result of further enlarging the angle range, the improvement of the strength of the end face was confirmed in the range of 85 to 140 degrees.

(experiment 3)

In experiment 3, the glass substrate was cross-scribed using a cutter wheel. The state of the intersection end face of the glass substrate subjected to cross scribing and the degree of depth (permeability) of the formed vertical crack were correlated with the cutting region of the cutting pressure, and the separability of the glass substrate was measured for each blade.

The division conditions are shown below.

Alkali-free glass of object glass substrate (glass veneer with thickness of 0.7 mm)

The material of the cutter wheel is as follows: sintered diamond

Outer diameter phi: 2.0mm

Thickness W: 0.65mm

The shaft aperture is as follows: 0.8mm

Pitch P of protrusions: 17.4 μm (equal division of the circumference)

Is 360)

Height h of the protrusion: 3 μm

Blade angle α: 110 deg. 115 deg. 120 deg

Marking device Mitsu Diamond Industrial Co Ltd MS model

Setting conditions of the glass substrate cutting depth: 0.1mm

Scribing speed: 300mm/sec

Cutting pressure: 0.04-0.21MPa

FIG. 8 shows the shape of the blade of the cutter wheel used as a sample and the result of cutting.

FIG. 8 shows the evaluation of the resolution of experiment 3, the evaluation method being as follows: 10 straight cross scribe lines were formed on the surface of the glass substrate along the X axis and the Y axis orthogonal to each other at 8mm × 8mm, and the state of crossing point jump was evaluated at 100 points formed. In the figure, n is 1, n is 2, and n is 3, and the evaluation n number (the number of times of repeated evaluations using a new blade, respectively) is indicated.

In the intersection check column in fig. 8, "full skip" indicates that no scribe line is formed before and after the intersection in the scribe line advancing direction, and "half skip" indicates that no scribe line is formed before and after the intersection in the scribe line advancing direction.

In the column of "penetration" in the cross point check column in fig. 8, the "o" mark indicates that the vertical crack stops to 10 to 20% of the thickness of the glass substrate and does not penetrate deep, and the "Δ" mark indicates that the vertical crack reaches 90% or more of the thickness of the glass substrate.

As is clear from fig. 8, when the cutting pressure is set to 0.08 to 0.17MPa, the occurrence of cross-over can be widely suppressed, and excessive penetration of the blade of the glass substrate can be suppressed.

Moreover, the angle alpha of the blade point is in the range of 110-120 degrees, so that a wider cutting area can be ensured for the cutting pressure. In this case, the angle range was further widened, and improvement of the corner chipping and the chipping was confirmed in the range of 85 to 140 °.

From experiment 3 it follows that: if used: the outer diameter of the wheel is 1.0-2.5mm, the projections are formed at 8-35 μm on the whole circumference of the ridge line part, the height of the projections is 0.5-6.0 μm, and the angle of the blade is 85-140 degrees, so that defects such as unfilled corners and squeezing cracks can be suppressed at the intersection point and the end face, and highly accurate scribing can be stably formed even when the thickness of the brittle material substrate is thin.

As is clear from the above-described embodiments, in the conventional cutter wheel 20 of the high penetration type, the cutter wheel 40 in which the pitch of the protrusions is further reduced (that is, the number of divisions is increased for the circumference) is used for scribing, whereby the strength of the end face of the glass substrate divided by the formed scribe line is increased, and a good scribe line can be formed even with a thin plate thickness.

Further, since the scribe line can be formed in a good condition in a wide cutting region, the scribe line can be formed stably for a long time without being affected by wear of the blade or variation in the forming position of the scribe line on the glass substrate.

By selectively using the conventional high-permeability cutter wheel 20 and the cutter wheel 40 of the present invention, a good scribing line can be formed for a wide range of substrate to be scribed from a thin plate to a thick plate.

Further, by reducing the pitch of the protrusions and the height of the protrusions, the strength of the divided end surface of the glass substrate divided by the formed scribe line can be increased, which can be easily understood by those skilled in the art.

Further, by adjusting the height or pitch of the projections of the cutter wheel 40, a good scribe line can be formed on a substrate having a thickness of 0.4mm or less, and the occurrence and extension of an unnecessary crack after division can be prevented.

(experiment 4)

In experiment 4, a split glass substrate (hereinafter, referred to as a sample substrate) as a sample was obtained by cross-scribing an uncoated glass substrate using cutter wheels (hereinafter, referred to as sample cutter wheels) having different numbers (pitches) of projections or different heights of projections at each blade portion, and then splitting the substrate.

The obtained sample substrate was subjected to a glass bending strength test, and the form of the protrusions was evaluated in relation to the strength of the glass substrate.

The division conditions are shown below.

Object glass substrate A) alkali-free glass (glass single plate with thickness of 0.63 mm)

Glass density 2.37

Uncoated glass substrate size: 370 x 470mm

Sample substrate: 100 x 15mm

B) Alkaline glass (glass veneer with thickness of 0.7 mm)

Glass density 2.50

Uncoated glass substrate size: 300X 400mm

Sample substrate: 100 x 15mm

C) Alkali-free glass (glass veneer with thickness of 0.7 mm)

Glass density 2.54

Uncoated glass substrate size: 360 x 460mm

Sample substrate: 100 x 15mm

The material of the sample cutter wheel is as follows: sintered diamond

Outer diameter phi: 2.0mm

Thickness W: 0.65mm

The shaft aperture is as follows: 0.8mm

Pitch P of protrusions: 17.4-57.1 μm (equally dividing the circumference into

110-360)

Height h of the protrusion: 3-10 μm

Blade angle α: 125 degree

Marking device Mitsu Diamond Industrial Co Ltd MS model

Scribing set-condition outside-outside cutting method (sample cutter wheel on uncoated glass substrate)

From one substrate end face portion to the other substrate end

Method for forming mark on face

Setting the cutting depth of the glass substrate: 0.15mm

Scribing speed: 300mm/sec

Cutting pressure: 0.22-0.25MPa

FIG. 9 shows a glass bending strength testing apparatus used for a glass bending strength test.

The test conditions for the glass bending strength test are shown below.

EzTest/CE, Shimadzu corporation of testing apparatus

Test method JIS R34204 Point bending test

Distance a between upper fulcrums: 20mm

Distance B between lower fulcrums: 60mm

Length C of one sample substrate: 100mm

Table 2 shows the form of the sample cutter wheel used, and the values of the cutting pressure and the amount of rib marks (depth of rib marks) were set. Samples nos. 1 and 2 in table 2 below are conventional cutter wheels having high permeability (cutter wheels described in patent document 2), and nos. 3 to 8 are cutter wheels according to the present invention.

[ Table 2]

The specific procedure of experiment 4 is shown below.

First, one side of the uncoated glass substrate was cross-scribed using the sample cutter wheels 1 to 6 of table 2. At this time, scribe lines were formed at the set cutting pressures shown in table 2 so that rib marks having a reference depth of 100 μm were formed on each uncoated glass substrate. In scribing, first, the sample cutter wheel is positioned outside the uncoated glass substrate and is formed from one substrate end surface portion to the other substrate end surface portion (outside-outside cutting method). The actual depth of the rib mark formed at each set cutting pressure is indicated in table 2 as "rib mark amount".

Thereafter, the uncoated glass substrate was divided by a manual folding method to obtain a plurality of sample substrates (100mm × 15 mm).

Next, a glass bending strength test was performed on each of the obtained sample substrates using a glass bending strength test apparatus shown in fig. 9.

In the glass bending strength test, a sample substrate was supported so that the surface on the side where the scribe line is formed by the cross scribe line was the lower surface side in the drawing, and the test was performed.

The numerical value (glass bending strength test result) of each sample cutter wheel for each sample substrate obtained by the glass bending strength test was plotted on weber (Weibull) probability paper. The results are shown in fig. 10, 12 and 14. Fig. 10 shows the results when the target glass substrate is a) alkali-free glass, fig. 12 shows the results when the target glass substrate is B) alkali-free glass, and fig. 14 shows the results when C) alkali-free glass.

Further, the sample substrate broken at the end of the glass bending strength test is analyzed for each broken surface, and the data is correlated with the sample cutter wheels 1 to 8 to calculate the occurrence rate of the breakage pattern.

The results are shown in fig. 11, 13 and 15. Fig. 11 shows the results when the target glass substrate is a) alkali-free glass, fig. 13 shows the results when the target glass substrate is B) alkali-free glass, and fig. 15 shows the results when C) alkali-free glass.

Further, the strength against the breakage of the sample substrate itself is high as the breakage pattern is shifted from left to right in the drawing (from pattern a to pattern H).

As is clear from fig. 10, 12, and 14, the strength of the obtained sample substrate tends to increase as the number of divided projections increases and the projection height is set from high to low in the sample cutter wheel used for scribing.

As is clear from fig. 11, 13, and 15, the sample cutter wheel used for scribing has a projection height set from high to low as the number of divided projections increases, and the strength of the end face of the sample substrate broken at the end of the glass bending strength test becomes large.

As shown in experiment 4, when the cutter wheel of the present invention in which the number of divided projections was increased and the height of the projection was set to be low was used to form a scribe line on a glass substrate, it was found that the bending strength and the end face strength of the glass substrate obtained by dividing the glass substrate into pieces and finally using the pieces as a sample substrate were increased, as compared with the case of using a conventional cutter wheel having high permeability (cutter wheel described in patent document 2).

(experiment 5)

In experiment 5, when the bonded glass substrate was cut using the cutter wheel 40 of the present invention, the relationship between the thickness of the bonded glass substrate and the condition of the blade and the cutting region of the cutting pressure was measured.

As shown in fig. 19, the method of cutting the bonded glass substrate includes placing a glass substrate G on a scribing table of a scribing apparatus with a glass substrate a facing upward, forming a scribe line Sa on the glass substrate a using a cutter wheel 40, then placing the glass substrate G on the scribing table with the glass substrate G turned upside down, and scribing the glass substrate B using the same cutter wheel 40 to form a scribe line Sb (hereinafter referred to as SS system).

The measurement results of the lower limit value and the upper limit value are expressed as the cutting region of the bonded glass substrate, which is a common cutting region between the cutting region (composed of the lower limit value and the upper limit value) of the cutting pressure of the SS type a-side glass substrate and the cutting region (composed of the lower limit value and the upper limit value) of the cutting pressure of the B-side glass substrate.

The division conditions are shown below.

Alkali glass and alkali-free glass for object-bonded glass substrate

The thickness of the glass substrate is 0.2-0.35mm (thickness of each of the A and B surfaces)

The material of the cutter wheel is as follows: sintered diamond

Outer diameter phi: 2.0mm

Thickness W: 0.65mm

The shaft aperture is as follows: 0.8mm

Pitch P of protrusions: 17.4 μm (circumference divided equally into 360)

Height h of the protrusion: 3 μm

Blade angle α: 95-120 deg. C

Marking device Mitsu Diamond Industrial Co Ltd MS model

Setting conditions of the glass substrate cutting depth: 0.1mm

Scribing speed: 200mm/sec

Cutting pressure: 0.04-0.18MPa

Table 3 shows the thickness and type of the bonded glass substrate used as a sample, the condition of the blade of the cutter wheel, and the lower limit value and upper limit value of the cutting region of the bonded glass substrate.

In table 3, "glass thickness" means the thickness of each of the a-side glass substrate and the B-side glass substrate constituting the bonded glass substrate. ") indicates" same as above.

As can be seen from table 3, when scribing bonded glass substrates of different materials and thicknesses using the cutter wheel 40, a wide and relatively low cutting region was obtained.

(other embodiment)

Fig. 16 is a front view of the cutter wheel 40 showing an enlarged front end side of the blade, illustrating an example of the method of manufacturing the cutter wheel 40 according to the present invention. The cutter wheel 40 is formed with a blade of a V-shaped ridge portion 20a along the circumferential portion of the disc-shaped wheel, and then, as shown in fig. 1 and 2, a concave-convex portion (groove 40b) is formed in the ridge portion 40 a.

In the present embodiment, the method of forming the blade edge is explained, and therefore, the formation of the unevenness (groove 40b) is not explained. The formation of the irregularities (grooves 40b) can be referred to the disclosure of japanese patent No. 3074143.

A method for forming the blade edge of the cutter wheel 40 according to the present invention (hereinafter referred to as "two-stage polishing method") will be specifically described with reference to fig. 16.

First, the blade of the disc wheel 10A is formed by rough grinding at least 1 blade angle θ 1 (blade of the profile shown by the solid line in the drawing).

When the cutter wheel 40 with the angle of the blade θ 1 is required, the disc-shaped wheel 10A with the rough-ground blade is ground again to form the wheel 10B with the angle of the blade θ 1. Next, by forming the unevenness (groove 40B) on this wheel 10B by the above-described method, the cutter wheel 40 having the blade angle θ 1 is obtained.

In the case of the cutter wheel 40 having the blade angle θ 2, the above-mentioned disc-shaped wheel 10A having the rough-ground blade is subjected to finish grinding to form a wheel 10C having the blade angle θ 2 (blade having a contour shown by a broken line in the figure). Next, by forming the unevenness (groove 40b) on this wheel 10C by the above-described method, the cutter wheel 40 having the blade angle θ 2 is obtained.

As described above, when a plurality of cutter wheels 40 (which can satisfy the requirement for stability) previously machined to one blade angle θ 1 are stored as a standard product and only a minute finishing polishing is performed, since various blade angles (θ 2.) can be manufactured in a short time, the number of man-hours can be greatly reduced, and a production system suitable for various small-scale production can be constructed.

The "two-stage polishing method" described above is applicable not only to the cutter wheel of the present invention but also to the cutter wheel 10 described in patent document 1 (i.e., a cutter wheel in which a V-shaped ridge portion is formed as a blade along the circumferential portion of a disk wheel) and the cutter wheel 20 described in patent document 2 (i.e., a cutter wheel in which a plurality of protrusions having a predetermined shape are formed at substantially equal intervals on the ridge portion of the cutter wheel 10).

As can be seen from embodiments 1 to 5, in the conventional cutter wheel 20 of the high penetration type, the strength of the end face of the glass substrate divided along the formed scribe line can be increased by using the cutter wheel 40 in which the pitch of the protrusions is reduced for scribing, and a satisfactory scribe line can be formed even in a thin plate.

Further, since the scribe region in which a good scribe line can be formed is wide, it is not easily affected by wear of the blade or variation in the formation position of the scribe line on the glass substrate, and a stable scribe line can be formed for a long time.

By selectively using the conventional high-permeability cutter wheel 20 and the cutter wheel 40 of the present invention, a good scribe line can be formed on a wide range of substrate to be scribed from a thin plate to a thick plate.

Further, by reducing the pitch of the protrusions and the height of the protrusions, the strength of the rear end face of the glass substrate split along the formed scribe line can be increased, which can be easily understood by those skilled in the art.

Further, even for a substrate having a plate thickness of 0.4mm or less, by adjusting the height of the projection of the cutter wheel 40, a satisfactory scribe line can be formed, and generation and extension of an unnecessary crack after chipping can be prevented.

Further, when the scribe line is formed on the glass substrate by using the cutter wheel 40 of the present invention, the glass substrate obtained by dividing the glass substrate thereafter can be improved in bending strength and end face strength.

Further, when the scribing line is formed on the glass substrate by using the cutter wheel 40 of the present invention, a wide and relatively low cutting area can be obtained for the bonded glass substrate of different material and thickness.

In the above-described embodiment, the cutter wheel 40 is shown by way of example in which the projections are formed uniformly around the entire circumference of the wheel, but the present invention is not limited to this, and the projections are formed only in a part of the circumference of the wheel, or are formed non-uniformly around the entire circumference of the wheel.

The cutter wheel and the scribing method of the brittle material substrate using the cutter wheel can inhibit the generation of crossing point jump, can stably form a scribing line with high precision even if the thickness of the brittle material substrate is thin, and can be used for scribing the brittle material substrate such as glass.

In particular, the scribing method of the present invention is very effective in scribing a brittle material substrate having a thickness in the range of 0.4mm to 0.7mm by applying a load of 0.03 to 0.19MPa to the brittle material substrate by the blade of the cutter wheel.

The present invention is particularly effective for glass substrates of alkali-free glass or synthetic quartz glass, and applications thereof include various brittle material substrates for various flat display panels such as TFT liquid crystal panels, TN liquid crystal panels, and STN panels.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (7)

1. A cutter wheel for cross scribing of a brittle material substrate, wherein a V-shaped ridge line portion is formed as a blade edge along a circumferential portion of a disk-shaped wheel, and a plurality of protrusions of a predetermined shape are formed at substantially equal intervals on the ridge line portion, characterized in that:

the outer diameter of the cutter wheel is 1.0-2.5mm, the protrusions are formed at intervals of 8-35 μm around the ridge portion, the height of the protrusions is 0.5-6.0 μm, and the angle of the blade is 85-140 deg.

2. The cutter wheel for cross scribing according to claim 1, wherein an angle of a blade of the cutter wheel is 95 to 140 °.

3. The cutter wheel for cross scribing according to claim 1, which is formed by sintering diamond or a super hard alloy material.

4. A scribing method of brittle material substrate, through pressing the cutter wheel to rotate on the brittle material substrate, in order to form the scribing on the surface of the brittle material substrate; the knife wheel is characterized in that a V-shaped ridge line part is formed along the circumference part of the disc-shaped wheel to be used as a knife edge, and a plurality of bulges are formed on the ridge line part at approximately equal intervals; the method is characterized in that:

the method for cross-scribing a brittle material substrate comprises using a cutter wheel having an outer diameter of 1.0-2.5mm, projections formed at a pitch of 8-35 μm over the entire circumference of the ridge line portion, a height of 0.5-6.0 μm, and an angle of a blade of 85-140 deg.

5. A method for dividing a brittle material substrate, comprising: the method comprises forming a scribe line on a brittle material substrate by cross scribing using the cutter wheel according to claim 1, and then applying a load along the formed scribe line to perform breaking.

6. A method for manufacturing a cutter wheel for cross scribing of a brittle material substrate, for manufacturing the cutter wheel according to claim 1, comprising the steps of:

roughly grinding the blade of the disc-shaped wheel at an angle theta 1 of at least 1 blade;

secondly, finely grinding the front end side of the blade at a blade angle theta 2 different from the blade angle theta 1; and

a plurality of grooves are formed at substantially equal intervals on a ridge portion where a V-shape is formed as a blade, thereby forming a plurality of protrusions.

7. A cutter wheel according to claim 1, wherein the cutter wheel is manufactured by the method for manufacturing a cutter wheel for cross scribing of a brittle material substrate according to claim 6.