JP7421162B2 - Glass plate manufacturing method - Google Patents

Description

The present invention relates to a manufacturing technique used to separate a glass plate having an outer contour shape corresponding to a closed curve from a mother glass having a cut line including a closed curve on its surface.

In the field of manufacturing glass plates, there is a manufacturing technology that forms closed curved scribe lines on the surface of the mother glass and separates from the mother glass a product with an outer contour shape corresponding to the closed curve, or a glass plate that is the source of the product. It is publicly known.

A specific example thereof is a method for manufacturing a glass plate disclosed in Patent Document 1. In this manufacturing method, first, a contour scribe line forming a closed curve and an auxiliary scribe line adjacent to the contour scribe line from the outside are formed on a mother glass (brittle material substrate in the publication). Next, the crack is extended along the auxiliary scribe line, and then the crack is extended from the auxiliary scribe line to the contour scribe line, thereby separating the glass plate (product substrate in the publication) from the mother glass. be.

Here, the contour scribe line disclosed in Patent Document 1 is understood to be a narrow groove-like line cut into the surface of the mother glass by a scribe wheel, a scribe cutter, etc. (See paragraphs [0015], [0016], etc. of the cited patent No. 5171522, and [Claim 2] of JP 2014-217982, which is listed as Patent Document 2 in the same document). When a contour scribe line is formed using such a method, a crack (lateral crack) extending in a direction parallel to the surface of the mother glass is formed at the edge of the scribe line. These lateral cracks remain in the glass plate after being separated from the mother glass, and thus become a factor that reduces the mechanical strength of the glass plate. Therefore, the end face of the glass plate needs chamfering or the like to remove lateral cracks, which increases the number of man-hours and prolongs the time required to manufacture the glass plate.

As a manufacturing method for dealing with such problems, there is a method for manufacturing a glass plate disclosed in Patent Document 2. This manufacturing method consists of a step of forming a concave line by plastic deformation on the surface of the mother glass using a scribing tip, a step of forming an initial crack at a position corresponding to the concave line, and a process of extending this initial crack along the concave line. The process includes a step of Note that the scribe line (crack C in the publication) obtained by extending the above-mentioned initial crack is formed not as a closed curve but as a straight line. According to this manufacturing method, concave lines without lateral cracks can be formed by plastically deforming the surface of the mother glass by pressing the scribe tip. As a result, the end face of the glass plate separated from the mother glass can be free from lateral cracks.

JP 2019-43010 Publication JP2019-89672A

By the way, when the method of forming a concave line by plastic deformation as disclosed in Patent Document 2 is applied to the method of forming a scribe line forming a closed curve as disclosed in Patent Document 1, the following problems occur. arise.

That is, if the shape of the planned cutting line having a closed curve includes a long curved portion or repeatedly includes straight and curved portions, the crack may stop extending in the middle of the concave line. When such a situation occurs, the mother glass has to be discarded, which may lead to deterioration in product yield and production efficiency.

In view of the above, the present invention aims to suppress the occurrence of lateral cracks and prevent initial cracks over the entire length of the concave lines due to plastic deformation in the scribing process of forming scribe lines including closed curves on the surface of the mother glass. The challenge is to ensure smooth expansion.

The present invention, which was created to solve the above problems, includes a mother glass and a scribe chip used for forming concave lines by plastic deformation on the surface of the mother glass by moving while pressing the surface of the mother glass. a scribing step of forming a scribe line along a planned cutting line including a closed curve on the surface of the mother glass; and a scribing step of forming a scribe line along the scribe line, and breaking the mother glass along the scribe line. a folding step of separating a glass plate having an outer contour shape corresponding to the closed curve from the substrate, and in the scribing step, the closed curve consists of a plurality of continuously connected unit closed curves on the surface of the mother glass. Assuming that the planned cutting line is composed of a plurality of planned unit cutting lines that separately include the plurality of unit closed curves, the scribe tip is cut separately along the plurality of planned unit cutting lines. By moving while pressing, a unit concave line is formed by plastic deformation for each of the plurality of unit cutting planned lines, and then initial cracks corresponding to each of the unit concave lines are formed, and the The scribe line is characterized in that a plurality of unit scribe lines are continuously connected by extending the initial cracks separately along the unit concave lines.

According to such a configuration, in the scribing step, first, it is assumed that the planned cutting line including the closed curve is composed of a plurality of planned unit cutting lines each including a plurality of unit closed curves separately, and A unit concave line is formed by plastic deformation for each line. This makes it difficult for lateral cracks to occur on the surface of the mother glass. Thereafter, a scribe line is formed by a plurality of initial cracks extending separately along the unit concave lines. Therefore, when forming a scribe line along a closed curve, one initial crack only needs to extend a distance shorter than the entire length of the concave line formed along the planned cutting line. As a result, the problem of the initial crack stopping in the middle of the concave line is less likely to occur, and the amount of discarded mother glass is reduced, thereby improving product yield and production efficiency.

In this manufacturing method, the plurality of unit cutting planned lines may be two unit cutting planned lines.

In this way, by changing the plurality of unit cutting planned lines to two unit cutting planned lines, the plurality of unit closed curves described above become two unit closed curves, and the plurality of unit concave lines due to the plurality of plastic deformations described above become , two unit concave lines due to plastic deformation, the plurality of initial cracks described above become two initial cracks, and the plurality of unit scribe lines described above become two unit scribe lines. In this way, the distance that each initial crack extends along the concave line can be halved.

In the above manufacturing method, in the scribing step, the unit closed curve may have a straight line portion and a curved line portion.

In this way, a special effect can be obtained by forming the closed curve into a plurality of unit closed curves. That is, since the initial crack becomes difficult to extend at a location where the concave line is curved, if the closed curve has curved portions at many locations, the probability that the initial crack will stop extending is increased. On the other hand, if the closed curve is made up of a plurality of unit closed curves, as in the configuration according to the present invention, the number of curved curved portions existing in each unit closed curve can be reduced, and the extension of the initial crack can be stopped. It is possible to reduce the probability of

In the above manufacturing method, in the scribing step, each of the plurality of planned unit cutting lines is made up of the unit closed curve and a unit extension line extending from one end of the unit closed curve to the outside of the closed curve. You can.

In this way, each of the plurality of unit cutting lines includes not only a unit closed curve but also a unit extension line, so each unit concave line formed along the unit cutting line is individually includes individual concave line portions corresponding to unit extension lines of . Therefore, by forming initial cracks in the respective concave line portions corresponding to these unit extension lines, it becomes possible to extend these initial cracks along the respective unit concave lines. This facilitates the work of forming a plurality of initial cracks.

In this manufacturing method, in the scribing step, one unit closed curve and another unit closed curve adjacent thereto among the plurality of unit closed curves each have a straight line portion and a continuous curved line portion, and the A unit extension line extending from one end of one unit closed curve extends along the same straight line as the straight line part of the one unit closed curve and extends along a tangent to the curved part of the other unit closed curve. You can do it like this.

In this way, the unit extension line extending from one end of one unit closed curve and the straight line part of one unit closed curve are connected on a straight line, so that along the concave line formed on the straight line, Initial cracks can be extended smoothly. In addition, since the unit extension line extending from one end of one unit closed curve extends along the tangent to the curved part of the other adjacent unit closed curve, it is formed along one unit closed curve. A connecting portion between a unit scribe line and a unit scribe line formed along another unit closed curve is formed smoothly. Therefore, if the connecting portion between two unit scribe lines is not formed smoothly, defects or the like may occur in the connecting portion, but with the configuration here, such defects are less likely to occur.

In these manufacturing methods, in the scribing step, the unit extension line may reach an edge of the mother glass.

This is advantageous when the scribe chip forms a concave line along the unit extension line from the central region of the mother glass toward the edge. Become. That is, in this case, when the scribe tip passes the edge of the mother glass, the scribe tip can make a cut (a scratch, a chip, etc.) on the edge to form an initial crack. Therefore, there is no need to separately form initial cracks using other tools, and the work for forming scribe lines can be simplified.

According to the present invention, in the scribing process of forming a scribe line including a closed curve on the surface of the mother glass, the initial crack can be smoothly extended over the entire length of the concave line due to plastic deformation while suppressing the occurrence of lateral cracks. can be done.

It is a process diagram showing the procedure of a method for manufacturing a glass plate according to an embodiment of the present invention. 1 is a perspective view showing a mother glass used in a method for manufacturing a glass plate according to an embodiment of the present invention. FIG. 2 is a perspective view showing the main parts of a scribe tip used in the method for manufacturing a glass plate according to an embodiment of the present invention. FIG. 2 is a schematic side view showing the action of a scribe tip used in the method for manufacturing a glass plate according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional front view showing concave lines formed on the surface of mother glass by the method for manufacturing a glass plate according to an embodiment of the present invention. FIG. 7 is a longitudinal sectional front view showing another example of the main part of the scribe chip used in the method for manufacturing a glass plate according to the embodiment of the present invention, and another example of the concave line formed on the surface of the mother glass by the manufacturing method. . FIG. 3 is a plan view for explaining a planned cutting line on the surface of the mother glass used in the method for manufacturing a glass plate according to the embodiment of the present invention. FIG. 2 is a plan view showing a process of forming scribe lines on mother glass by a method for manufacturing a glass plate according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional front view showing a state in which initial cracks are formed in mother glass by the method for manufacturing a glass plate according to an embodiment of the present invention. FIG. 3 is a perspective view showing a process in which an initial crack formed in mother glass expands by the method for manufacturing a glass plate according to an embodiment of the present invention. FIG. 2 is a plan view showing a state in which scribe lines are formed on mother glass by a method for manufacturing a glass plate according to an embodiment of the present invention. It is a top view which shows the state where the scribe line was formed in mother glass by the first modification of the manufacturing method of the glass plate based on embodiment of this invention. It is a top view which shows the state in which the scribe line was formed in mother glass by the second modification of the manufacturing method of the glass plate based on embodiment of this invention. It is a top view which shows the state where the scribe line was formed in mother glass by the third modification of the manufacturing method of the glass plate based on embodiment of this invention. FIG. 15(a) is a plan view showing the process of breaking the mother glass by the method of manufacturing a glass plate according to the embodiment of the present invention, and FIG. 15(b) is a plan view taken along the ZZ line in FIG. 15(a). FIG. FIG. 16(a) is an enlarged longitudinal sectional front view showing the process of breaking the mother glass according to the method of manufacturing a glass plate according to the embodiment of the present invention, and FIG. FIG. 3 is an enlarged longitudinal sectional front view showing a state in which the mother glass has been completely broken by the plate manufacturing method.

EMBODIMENT OF THE INVENTION Hereinafter, the manufacturing method of the glass plate based on embodiment of this invention is demonstrated with reference to an accompanying drawing.

As shown in FIG. 1, the method for manufacturing a glass plate includes a preparation step 1 of preparing a mother glass and a scribe chip, a scribing step 2 of forming a scribe line along a planned cutting line on the surface of the mother glass, and a scribing step 2 of forming a scribe line along a planned cutting line on the surface of the mother glass. A breaking step 3 is provided in which the glass plate is separated from the mother glass by breaking the glass along the scribe line.

FIG. 2 illustrates the mother glass G prepared in the preparation step 1. The mother glass G has a rectangular shape, and the planned cutting line 4 on the surface Gh includes a closed curve 4R. The size of the mother glass G is not particularly limited, but it is preferable that the length of one side is 50 mm or more, and the thickness t is preferably 0.01 mm to 1 mm, and 0.01 mm to 0.7 mm. It is more preferable that there be.

3 and 4 illustrate the scribe tip 5 prepared in the preparation step 1. The scribing tip 5 is of a pencil type and has a shank 5a and a tip 5b fixed to the end of the shank 5a. The holder 5c holding the shank 5a moves the scribing tip 5 vertically and horizontally. Moreover, the holder 5c can freely change the inclination angle of the shank 5a with respect to the mother glass G.

The tip 5b is preferably a monocrystalline or polycrystalline diamond tip, for example, but may also be made of PCBN, ceramic, cemented carbide, or other metal. The shape of the chip 5b is a truncated cone shape with a planar end surface 5d, and a pressing portion 5e that contacts the mother glass G and has an arc shape in plan view is formed at the end of the chip 5b. Specifically, the pressing portion 5e is the edge of the end surface 5d at the axial tip of the chip 5b. In this case, the scribe tip 5 moves in an inclined state (the inclination angle is, for example, 30° to 85°) with respect to the surface Gh of the mother glass G. During movement in this inclined state, the pressing portion 5e (edge of the end surface 5d) moves in the direction of the arrow X while pressing the surface Gh of the mother glass G, causing plastic deformation on the surface Gh, and this plastic deformation portion A concave line 6 is formed. The radius (radius of curvature) of the pressing portion 5e is preferably 0.001 mm to 1 mm, more preferably 0.025 mm to 0.5 mm.

FIG. 5 is a diagram (a sectional view perpendicular to the direction in which the concave line 6 extends) showing the peripheral state of the concave line 6 having a curved cross section. As shown in the figure, the depth D1 of the concave line 6 is, for example, 300 nm to 500 nm, and the width W1 of the concave line 6 is, for example, 15 μm to 30 μm. A compressive stress layer 7 due to plastic deformation is formed inside the concave line 6, and a tensile stress layer 8 is formed in an internal region inside the compressive stress layer 7. In addition, at the ends of the concave lines 6 in the width direction, protrusions 9 that protrude from the surface Gh are formed over the entire length of the concave lines 6 by plastic deformation. The protrusion amount h of the protrusion 9 from the surface Gh is, for example, 10 nm to 20 nm.

In this case, as the scribe tip 5, as shown in FIG. 6, it is possible to use a tip that has a V-shaped tip 5b at the tip of a shank 5a, and the tip of this tip 5b is used as a pressing part 5e. can. The mode of using this scribe tip 5 is substantially the same as the mode shown in FIG. 4. When this scribe tip 5 is used, a concave line 9 having a V-shaped cross section is formed on the surface Gh of the mother glass G, as shown in FIG. A tensile stress layer 8 is formed. In the following description, for convenience, the case where the scribe tip 5 shown in FIG. 3 described above is used will be taken as an example.

FIG. 7 is a plan view illustrating the surface Gh of the mother glass G used when performing the scribing step 2. As shown in the figure, the planned cutting line 4 on the surface Gh of the mother glass G includes a closed curve 4R in which the four corners of a rectangle are curved into circular arcs. The planned cutting line 4 is assumed to be composed of a first planned unit cutting line 4A shown by a thick chain line and a second planned unit cutting line 4B shown by a thin chain line. Further, the closed curve 4R is assumed to be composed of a first unit closed curve 4R1 of the first unit cutting planned line 4A and a second unit closed curve 4R2 of the second unit cutting planned line 4B. It is assumed that the first unit closed curve 4R1 consists of two straight line portions 4A1 and 4A2 and two curved line portions 4a1 and 4a2. The second unit closed curve 4R2 is assumed to consist of two straight line portions 4B1 and 4B2 and two curved line portions 4b1 and 4b2. Furthermore, it is assumed that the first unit cutting line 4A has a first unit extension line 4A3 extending from one end of the first unit closed curve 4R1 to the outside of the closed curve 4R. It is assumed that the second unit cutting line 4B has a second unit extension line 4B3 extending from one end of the second unit closed curve 4R2 to the outside of the closed curve 4R. In this case, the first unit extension line 4A3 extends from one end of the straight portion 4A1 (the upper end in the paper) along the same straight line as the straight portion 4A1, and extends from the edge of the mother glass G (the upper end in the paper). Edge) Gx has been reached. Further, the second unit extension line 4B3 extends from one end of the straight portion 4B1 (the lower end in the paper) along the same straight line as the straight portion 4B1, and extends from the edge of the mother glass G (the lower end in the paper). edge) has reached Gy.

In the scribing step 2, as shown in FIG. 8, the scribing tip 5 is moved while pressing the mother glass G along the first unit cutting line 4A, thereby forming the first unit by plastic deformation. A concave line 6A is formed. Specifically, the scribe tip 5 cuts from the starting point 4Ax (one end of the curved line portion 4a2) of the first unit cutting planned line 4A to the curved line portion 4a2, the straight line portion 4A2, the curved line portion 4a1, the straight line portion 4A1, and the first unit cutting line 4A. It moves on the unit extension line 4A3 in the direction shown by the arrow A, and reaches the end point 4Ay of the first unit cutting planned line 4A (one end of the first unit extension line 4A3). As a result, the first unit concave line 6A having a cross-sectional shape as shown in FIG. 5 described above is formed. In this case, at the end point 6Ay of the first unit concave line 6A, the scribe tip 5 makes a cut (a scratch, a chip, etc.) on the edge Gx of the mother glass G, so that at the end point 6Ay of the first unit concave line 6A, As shown in FIG. 9, a first initial crack 10 is formed in the tensile stress layer 8. As time passes thereafter, the first initial crack 10 extends along the first unit concave line 6A due to the action of the tensile stress of the tensile stress layer 8, thereby extending the entire length of the first unit concave line 6. A first unit scribe line 11A is formed along the line. The extension of this first initial crack 10 starts from the end point 6Ay of the first unit concave line 6A as shown by the arrow Y in FIG. 10, and ends at the start point 6Ax of the first unit concave line 6A shown in FIG. Complete as. The first unit scribe line 11A is formed by the first initial crack 10 extending within the tensile stress layer 8. Therefore, the first unit scribe line 11A does not reach the surface Gh of the mother glass G (the surface of the concave line 6A) due to the presence of the compressive stress layer 7. Note that this first unit scribe line 11A may be made to reach the surface Gh of the mother glass G by reducing the pressing force of the scribe tip 5 and reducing the thickness of the compressive stress layer 7 (described later). The same applies to the second unit scribe line 11B).

Next, in the scribing step 2, as shown in FIG. 11, in the scribing step 2, as shown in FIG. A second unit concave line 6B is formed by deformation. To be more specific, the second unit concave line 6B is formed by the scribing tip 5 moving over the curved line portion 4b2, the straight line portion 4B2, the curved line portion 4b1, the straight line portion 4B1, and the second unit extension line 4B3. This is done by moving in the direction shown by arrow B. Thereafter, a second initial crack 12 as shown in FIG. 9 is formed at the end point 6By of the second unit concave line 6B, and then an initial crack 12 is formed from the end point 6By of the second unit concave line 6B toward the start point 6Bx. By stretching (see FIG. 10), a second unit scribe line 11B is formed along the entire length of the second unit concave line 6B shown in FIG. As a result of the above, the mother glass G has a scribe line 11 in which the first unit scribe line 11A and the second unit scribe line 11B are continuously connected, that is, a scribe line 11 along the entire length of the planned cutting line 4 including the closed curve 4R. is formed.

In the scribing step 2 described here, the second unit concave line 6B is formed after the first unit concave line 6A is formed, but the second initial crack 12 starts to expand after the first initial crack 10 has finished expanding. If so, the two unit concave lines 6A and 6B may be formed at the same time. Further, the scribe chips 5 for forming the two unit concave lines 6A and 6B may be the same or different ones.

According to the scribing step 2 as described above, the following effects are achieved. That is, since both the first unit concave line 6A and the second unit concave line 6B are formed by plastic deformation due to pressure, lateral cracks are less likely to occur on the surface Gh of the mother glass G. Furthermore, since the two initial cracks 10 and 12 extend separately along the two unit concave lines 6A and 6B, in order to form the scribe line 11 along the planned cutting line 4, the two initial cracks 10 and 12 are extended separately. It is sufficient to extend only half of the total length of the two unit concave lines 6A and 6B. This eliminates the problem that may occur when one initial crack extends over the entire length of the concave line, which is the total length of the two unit concave lines 6A and 6B, that is, the problem that the extension of the initial crack stops in the middle of the concave line. It becomes difficult to occur. As a result, the amount of discarded mother glass G is reduced, thereby improving product yield and production efficiency.

In addition, since the initial crack is particularly difficult to extend in the curved portion of the closed curve 4R of the planned cutting line 4, the four curved portions 4a1, 4a2, 4b1, and 4b2 are extended for one initial crack as in the above example. If you try to do so, the probability that the initial crack will stop growing increases. However, in the scribing step 2 here, it is sufficient to extend only two curved portions for one initial crack, so that the probability that the extension of the initial crack stops can be reduced.

Furthermore, in the scribing step 2 here, the straight part 4A1 of the first unit closed curve 4R1 and the first unit extension line 4A3 are connected in a straight line, and the straight part 4B1 of the second unit closed curve 4R2 and the second unit extension line are connected in a straight line. 4B3 are connected in a straight line, so that the initial cracks 10 and 12 can each be extended smoothly along the concave line portion formed in the continuous portion. Further, the first unit extension line 4A3 extends along the tangent to the curved line portion 4b2 of the second unit closed curve 4R2, and the second unit extension line 4B3 extends along the tangent to the curved line portion 4a2 of the first unit closed curve 4R1. , the connecting portion between the two unit scribe lines 11A and 11B can be formed smoothly. Therefore, if the connecting portion between the two unit scribe lines 11A and 11B is not formed smoothly, defects may occur in the connecting portion, but according to the scribing process 2 here, such defects will not occur. It becomes difficult.

In addition, in the scribing step 2 here, since the two unit extension lines 4A3 and 4B3 have reached the edges Gx and Gy of the mother glass G, respectively, the two initial cracks 10 and 12 can be formed. Therefore, there is no need to separately form these initial cracks 10 and 12 using other tools, and the work for forming the scribe line 11 is simplified.

FIG. 12 shows a first modification of the scribing process 2. In this first modification, four unit concave lines 6C, 6D, 6E, and 6F are separately formed on the surface Gh of the mother glass G, and initial cracks are separately formed along these unit concave lines 6C to 6F. By stretching, a scribe line 11 is formed in which four unit scribe lines 11C, 11D, 11E, and 11F are continuously connected. Specifically, the first unit scribe line 11C is such that the scribe tip 5 moves in the direction indicated by the arrow C on the curved line portion 4C1, the straight line portion 4C2, and the first unit extension line 4C3 of the planned cutting line 4. It was formed by this. The second unit scribe line 11D is formed by moving the scribe tip 5 in the direction shown by the arrow D on the curved part 4D1, the straight part 4D2, and the second unit extension line 4D3 of the planned cutting line 4. It is something that The third unit scribe line 11E is formed by moving the scribe tip 5 in the direction shown by the arrow E on the curved part 4E1, the straight part 4E2, and the third unit extension line 4E3 of the planned cutting line 4. It is something that The fourth unit scribe line 11F is formed by moving the scribe tip 5 in the direction shown by the arrow F on the curved part 4F1, the straight part 4F2, and the fourth unit extension line 4F3 of the planned cutting line 4. It is something that Note that the shape of the closed curve 4R is the same as the closed curve 4R shown in FIG. 7 described above. Further, a process of separately forming four unit concave lines 6C to 6F, a process of separately forming four initial cracks, and a process of separately extending four initial cracks along four unit concave lines 6C to 6F. is based on the matters already explained in detail.

FIG. 13 shows a second modification of the scribing process 2. In this second modification, on the surface Gh of the mother glass G, the closed curve 4R is made circular, two unit concave lines 6H and 6I are separately formed, and the unit concave lines 6H and 6I are By extending initial cracks separately, a scribe line 11 in which two unit scribe lines 11H and 11I are continuously connected is formed. Specifically, the first unit scribe line 11H is a scribe tip in the direction shown by the arrow H above the semicircular portion 4H1 of the planned cutting line 4 and the first unit extension line 4H2 extending linearly from one end of the semicircular portion 4H1. 5 was formed by moving. Further, the second unit scribe line 11I is such that the scribe tip 5 moves in the direction indicated by the arrow I above the semicircular portion 4I1 of the planned cutting line 4 and the second unit extension line 4I2 extending linearly from one end of the semicircular portion 4I1. It is formed by movement. In addition, a process of separately forming two unit concave lines 6H and 6I, a process of separately forming two initial cracks, and a process of separately extending four initial cracks along two unit concave lines 6H and 6I. is based on the matters already explained in detail.

FIG. 14 shows a third modification of the scribing process 2. In this third modification, on the surface Gh of the mother glass G, the closed curve 4R is made circular in the same way as above, and four unit concave lines 6J, 6K, 6L, and 6M are formed separately, and these units are A scribe line 11 in which four unit scribe lines 11J, 11K, 11L, and 11M are continuously connected is formed by extending initial cracks separately along concave lines 6J to 6M. Specifically, the first unit scribe line 11J scribes in the direction shown by arrow J above the quarter-circular portion 4J1 of the planned cutting line 4 and the first unit extension line 4J2 extending linearly from one end thereof. It is formed by the movement of the chip 5. On the second unit scribe line 11K, the scribe tip 5 moves in the direction shown by the arrow K on the quarter-circular part 4K1 of the planned cutting line 4 and the second unit extension line 4K2 extending linearly from one end of the quarter-circular part 4K1. It was formed by On the third unit scribe line 11L, the scribe tip 5 moves in the direction indicated by the arrow L over the quarter-circular portion 4L1 of the planned cutting line 4 and the third unit extension line 4L2 extending linearly from one end thereof. It was formed by On the fourth unit scribe line 11M, the scribe tip 5 moves in the direction shown by the arrow M on the quarter-circular portion 4M1 of the planned cutting line 4 and the fourth unit extension line 4M2 extending linearly from one end thereof. It was formed by Note that the process of forming four unit concave lines 6J to 6M separately, the process of forming four initial cracks separately, and the process of extending initial cracks separately along four unit concave lines 6J to 6M are as follows: Based on what has already been explained in detail.

In addition, in the embodiments shown in FIGS. 11 to 14 described above, each unit extension line reaches the edge of the mother glass, but each unit extension line does not reach the edge of the mother glass. It doesn't have to be reached. In this case, the initial crack can be formed, for example, by pressing and moving a scribe wheel across the unit extension line on the surface of the mother glass. Moreover, it is also possible to have a configuration in which each unit extension line is not provided. In this case, the initial crack can be formed, for example, by separately pressing a pin-shaped member or the like onto one location of each unit concave line.

Next, the folding process 3 executed after the above-mentioned scribing process 2 will be explained. This folding step 3 utilizes negative pressure suction. Further, this folding step 3 will be described with reference to the mother glass G on which the scribe line 11 of the form shown in FIG. 11 is formed. To execute the folding process 3, the support member 13 shown in FIGS. 15(a) and 15(b) is used. The support member 13 has a flat support surface 13a for supporting the mother glass G in a horizontal position, and is provided with a groove-shaped recess 14 on the support surface 13a. The recess 14 is formed so that the recess 14 extends along the scribe line 11 when the mother glass G is supported by the support member 13. Note that the support member 13 is preferably made of resin or the like in order to prevent scratches or the like from occurring when the mother glass G is placed thereon.

The recess 14 has a rectangular profile in a cross section perpendicular to the direction in which the groove extends. A large number of suction holes (not shown) are formed in the inner wall surface 14a of the recess 14, and each suction hole is connected to a negative pressure generation source (not shown) such as a vacuum pump. As a result, by operating the negative pressure generation source while the recess 14 is covered with the mother glass G, gas within the recess 14 is sucked through the suction hole, and negative pressure is generated within the recess 14. It is now possible.

When performing the folding step 3 using the apparatus configured as described above, as shown in FIGS. The mother glass G is placed on the support member 13 so that the mother glass G is in contact with the support surface 13a of the support member 13. Further, the mother glass G is placed on the support member 13 so that the scribe line 11 formed on the mother glass G is located at the center of the opening width of the recess 14. In addition, the mother glass G on the support member 13 is covered with the cover member 15. The cover member 15 includes a flexible and airtight sheet body 16 and a holder 17 that holds the sheet body 16. The holding body 17 does not deform even when negative pressure is generated, but the sheet body 16 has a characteristic that it easily bends when negative pressure is generated.

Under such conditions, as shown in FIG. 16(a), the negative pressure source is operated to suck the gas in the sealed recess 14 as shown by the arrow W, and the gas inside the recess 14 is generates negative pressure. Then, by using negative pressure, the peripheral area of the scribe line 11 existing on the recess 14 is curved so that the surface Gh side becomes convex, and the stress generated thereby causes the median crack included in the scribe line 11 to be removed from the mother glass G. Stretch in the thickness direction. Thereby, as shown in FIG. 16(b), the mother glass G is broken starting from the scribe line 11, and the glass plate G1 having an outer contour shape of the closed curve 4R is separated from the mother glass G. This glass plate G1 becomes the product or the source of the product, and the remaining glass portion G2 becomes an unnecessary portion. According to this breaking step 3 using negative pressure suction, advantages such as a high-quality broken surface of the glass plate G1 can be obtained.

The method for manufacturing a glass plate according to the present invention is not limited to the aspects described in the above embodiments. For example, the shape of the closed curve of the planned cutting line may be other than the shape exemplified above, or it may be assumed that the planned cutting line consists of a number of unit cutting planned lines other than the number exemplified above. Furthermore, the breaking process may employ a method of applying an external force by pressing a tool or the like to the outer region of the closed curve of the mother glass, instead of using negative pressure suction.

1 Preparation process 2 Scribe process 3 Folding process 4 Cutting plan line 4A Unit cutting plan line 4A3 Unit extension line 4B Unit cutting plan line 4B3 Unit extension line 4R Closed curve 4R1 Unit closed curve 4R2 Unit closed curve 5 Scribe tip 6 Concave line 6A Unit Concave line 6B Unit concave line 10 Initial crack 11 Scribe line 11A Unit scribe line 11B Unit scribe line 12 Initial crack G Mother glass G1 Glass plate Gh Surface of glass plate Gx Edge of glass plate Gy Edge of glass plate

Claims (6)

a preparation step of preparing a mother glass and a scribing tip used to press and move the surface of the mother glass to form a concave line by plastic deformation on the surface of the mother glass; A scribing step of forming a scribe line along a planned cutting line including a closed curve, and breaking the mother glass along the scribe line to produce a glass plate having an outer contour shape corresponding to the closed curve from the mother glass. A folding process for separating;
In the scribing step, it is assumed that on the surface of the mother glass, the closed curve is composed of a plurality of unit closed curves that are continuously connected, and the planned cutting line is composed of a plurality of units that separately include the plurality of unit closed curves. Assuming that the scribing tip consists of planned cutting lines, by moving the scribe tip while pressing it separately along the plurality of planned unit cutting lines, a unit concave line is formed by plastic deformation for each of the plurality of planned unit cutting lines. , and then forming initial cracks corresponding to the unit concave lines, respectively, and extending these initial cracks separately along the unit concave lines, thereby forming a plurality of unit scribe lines. A method for manufacturing a glass plate, comprising forming the scribe line in which the scribe lines are continuously connected. The method for manufacturing a glass plate according to claim 1, wherein in the scribing step, the plurality of planned unit cutting lines are two planned unit cutting lines. 3. The method for manufacturing a glass plate according to claim 1, wherein in the scribing step, each of the plurality of unit closed curves has a straight line portion and a curved line portion. In the scribing step, each of the plurality of planned unit cutting lines comprises the unit closed curve and a unit extension line extending from one end of the unit closed curve to the outside of the closed curve. A method for manufacturing a glass plate as described in . In the scribing step, one unit closed curve and another adjacent unit closed curve among the plurality of unit closed curves each have a straight line part and a curved part continuous to this, and the unit closed curve of the one unit closed curve 5. The unit extension line extending from one end extends along the same straight line as the straight line part of the one unit closed curve and extends along the tangent to the curved part of the other unit closed curve. A method of manufacturing a glass plate. 6. The method for manufacturing a glass plate according to claim 4, wherein in the scribing step, the unit extension line reaches an edge of the mother glass.