WO2015115604A1

WO2015115604A1 - Laser melt-cutting method and plate-form glass product having melt-cut face

Info

Publication number: WO2015115604A1
Application number: PCT/JP2015/052697
Authority: WO
Inventors: 尚利稲山
Original assignee: 日本電気硝子株式会社
Priority date: 2014-02-03
Filing date: 2015-01-30
Publication date: 2015-08-06
Also published as: TW201542479A; JPWO2015115604A1; JP6350884B2

Abstract

When irradiating a laser (11) onto a workpiece (1) having a plate form, while causing the laser (11) to scan along a planned cutting line which is a closed curve (4) on the workpiece (1), and melting the workpiece (1) in order to cut the work piece (1) into a product portion (2) and a non-product portion (3), the method adopts a trajectory wherein the laser (11) is caused to enter from the non-product portion (3) side onto the planned cutting line (4) and scan along the planned cutting line (4), and then the laser (11) is caused to leave from above the planned cutting line (4) to the non-product portion (3) side. Then, a leaving start position (P4), which is where the laser (11) starts leaving from above the planned cutting line (4), is offset more to the tailing side of the laser (11) scanning direction than an entry start position (P3), which is where the laser (11) starts entering onto the planned cutting line (4).

Description

Laser cutting method and sheet glass product having a melting section

The present invention relates to a laser fusing method for cutting a workpiece into a predetermined shape by irradiating a workpiece such as a plate glass with a laser and melting a region irradiated with the laser, and a plate glass product having a molten section. About.

For example, one of the processing methods for sheet glass products is a technique called laser fusing. This method irradiates a sheet glass with a laser and scans the laser along a trajectory along the cutting line of the sheet glass, thereby melting the region of the sheet glass irradiated with the laser, It is a method of cutting out a sheet glass product having a shape according to the scanning trajectory from the sheet glass.

In the manufacturing process of a sheet glass product, cutting the peripheral part of the sheet glass formed by a known method to cut out the product part, or cutting out a plurality of product parts from one sheet of glass is performed. It has been broken. Such a cut-out operation is performed, for example, by cutting a product portion from a sheet glass by laser fusing (see, for example, FIG. 2 (c) of Patent Document 1).

In this way, when considering cutting out the product part from the sheet glass by laser cutting, a laser irradiation start position will be provided on the planned cutting line, but if laser irradiation is started from such a position, irradiation will be performed. There is a problem that microcracks are likely to occur in the vicinity of the start position. There is a similar problem with respect to the irradiation end position. Therefore, means for preventing the occurrence of microcracks in the product part by setting the irradiation start position and the irradiation end position of the laser at positions away from the product part (or planned cutting line) of the workpiece has been proposed. (See Patent Document 2).

JP-A-60-251138 JP 2007-319888 A

In this way, the cutting of the sheet glass product by laser fusing is performed by melting the workpiece by heating by laser irradiation, so in order to reduce the influence of heating on the product portion, It is necessary to devise ways to avoid laser irradiation as much as possible. Here, when laser cutting was examined for cutting out an actual sheet glass product, if the method described in Patent Document 2 was applied to cutting out a sheet glass product, the product portion (sheet glass product) A certain deterrent effect was observed against the occurrence of microcracks. However, on the other hand, it has been found that the product portion is heated to a level that cannot be ignored in the vicinity of the region where the laser scanning traces intersect. Hereinafter, it will be described in detail with reference to the drawings.

FIG. 13 is a plan view for conceptually explaining an example of cutting out the product portion 102 from the sheet glass 101 by laser cutting. As shown in FIG. 13, laser fusing to the plate glass 101 is performed by irradiating a laser 112 from the laser irradiation device 111 (indicated by a two-dot chain line in FIG. 13) toward the plate glass 101 and this laser irradiation device. This is performed by scanning the laser 112 by relative movement between the glass 111 and the plate glass 101. The laser 112 scans around the product portion 102 (draws a closed curve) along a planned cutting line 103 (indicated by a one-dot chain line in FIG. 13) according to the shape of the product portion 102 to be cut out. Is done. Here, as described in Patent Document 2, the irradiation start position P11 and the irradiation end position P12 of the laser 112 are set outside the planned cutting line 103 as viewed from the product part 102, that is, on the non-product part 104 side. The laser 112, for example, enters the straight line region 103a along the predetermined side of the product portion 102 of the planned cutting line 103 that forms a closed curve, and makes a round along the planned cutting line 103 and then on the straight line region 103a. A trajectory 120 that departs from the outside is drawn.

FIG. 14 is an enlarged view of the vicinity of the entry start position P13 of the laser 112 on the planned cutting line 103 and the separation start position P14 on the planned cutting line 103. FIG. As shown in FIG. 14, the slits 121 that have a certain width dimension L around the planned cutting line 103 and penetrate the plate glass 101 in the front and back directions are melted by the irradiation of the laser 112. It is formed. Since the width dimension L of the slit 121 is necessarily smaller than the width dimension of the irradiation region 113 of the laser 112 on the surface of the plate-like glass 101 (in FIG. 14, the region subjected to fine line hatching), that is, the spot diameter D. The laser 112 is also irradiated on both sides in the width direction of the slit 121, and the regions on both sides in the width direction of the slit 121 are heated not a little. Therefore, as shown in FIGS. 13 and 14, when the laser 112 scans around the product portion 102 along the planned cutting line 103 for just one round, the laser 112 enters the start start position P13 and the start start position P14. The scanning trajectory 120 of the laser 112 intersects at the entry start position P13 (that is, the departure start position P14). As a result, the peripheral portion of the product portion 102 is irradiated with the laser 112 twice immediately after the start of fusing and immediately before the end of fusing. As described above, the region irradiated with the laser 112 in an overlapping manner is excessively heated as compared with the other portions, so that deformation due to softening or the like is caused, resulting in deterioration of the shape quality of the product portion 102. There is a fear.

In view of the above circumstances, it is a technical problem to be solved by the present invention to cut out a product part from a workpiece by laser cutting while ensuring shape quality.

The solution to the above problem is achieved by the laser fusing method according to the present invention. That is, this fusing method irradiates a part or the whole of a plate-shaped workpiece with laser, scans the laser along the planned cutting line of the workpiece that is a closed curve, and melts the workpiece, A laser fusing method that divides a workpiece into a product part and a non-product part. The laser enters the cutting line from the non-product part side, scans along the cutting line, and then the laser is cut off from the cutting line. In a product that has a trajectory to be separated to the product part side, the separation start position at which the laser starts separation from the planned cutting line is set behind the laser scanning direction from the entry start position at which the laser starts entering the planned cutting line. Characterized by a point offset to the side.

As described above, in the present invention, normally, the laser is scanned so as to make a round around the product part or the non-product part along the planned cutting line according to the shape of the product part or the non-product part to be cut. However, the departure start position where the laser starts to leave the planned cutting line is intentionally offset to the rear side in the scanning direction of the laser from the start position where the laser starts entering the planned cutting line. In other words, the laser starts to leave the planned cutting line before going around the planned cutting line. In this way, without sticking to the shape of the planned cutting line, by separating the laser from the planned cutting line to the non-product part side as early as possible so that substantial cutting is possible, out of the peripheral part of the product part The area of the region where laser irradiation is performed in an overlapping manner can be kept small. As a result, excessive heating of the peripheral portion of the product portion around the laser entry start position can be suppressed, and softening and deformation of the peripheral portion can be prevented as much as possible.

Here, as a specific application target of the present invention, a case where a product part surrounded by the planned cutting line is cut out from the work by scanning the laser along the planned cutting line and melting the work can be considered. . Or the case where the product part which hollowed out the area | region enclosed by the cutting cutting line is considered by scanning a laser along a cutting cutting line and fuse | melting a workpiece | work is considered. Here, when cutting out the product part, the laser enters the cutting line from the side of the non-product part located outside the cutting line, scans along the cutting line, and then scans the laser on the cutting line. It is better to take a trajectory for separating from the non-product part side. In addition, when obtaining a product part in which the area surrounded by the planned cutting line is cut out, the laser enters the cutting target line from the side of the non-product part located inside the planned cutting line and follows the planned cutting line. After scanning, it is preferable to take a trajectory for separating the laser from the planned cutting line toward the non-product part.

Further, in the laser fusing method according to the present invention, the laser may enter the planned cutting line so that the laser scanning trajectory when passing through the entry start position is in contact with the planned cutting line. Alternatively, the laser may be separated from the planned cutting line so that the scanning trajectory of the laser when passing the separation start position is in contact with the planned cutting line.

According to the present invention, the scanning locus is bent at the approach start position when entering at a predetermined angle with respect to the planned cutting line because the laser takes a scanning locus to enter the planned cutting line from the non-product part side. Change of direction is necessary. In this case, since the scanning speed of the laser is lowered when the direction is changed, the laser irradiation time at the direction changing position (entrance start position) becomes longer, and there is a problem that the heating amount increases accordingly. Here, if the laser is allowed to enter so that the laser scanning trajectory when passing the entry start position is in contact with the planned cutting line, the approach trajectory of the laser on the planned cutting line is asymptotic to the planned cutting line, for example. Can be curved. Therefore, laser fusing can be advanced without reducing the scanning speed at the start of entry, and excessive heating of the product part can be suppressed. The above description applies similarly when the laser is separated from the planned cutting line toward the non-product part. Therefore, by detaching the laser so that it is parallel to the planned cutting line at the detachment start position, laser fusing can be completed without reducing the scanning speed even at the start of detachment.

Further, the laser fusing method according to the present invention may be one in which the laser is scanned so that the laser starts an approach on the planned cutting line while drawing an arcuate locus. Alternatively, the laser may be scanned so that the laser draws an arc-shaped trajectory and starts to leave the planned cutting line.

If the laser starts to enter the planned cutting line by drawing an arc-shaped trajectory, the laser approach angle at the approach start position (the angle formed by the laser scanning direction and the planned cutting line) should be minimized. Can do. Thereby, since the laser direction change to the direction along the planned cutting line can be minimized, the laser fusing can be advanced without reducing the scanning speed as much as possible at the start of the approach. Of course, as described above, from the viewpoint of maintaining the scanning speed, the laser should be allowed to enter the planned cutting line with an arc-shaped trajectory so that the laser scanning trajectory when passing the approach start position is in contact with the planned cutting line. It's even better. The above description also applies to the case where the laser is separated from the planned cutting line toward the non-product part. Therefore, if the laser starts to detach from the planned cutting line to the non-product part side by drawing an arc-shaped trajectory, the laser fusing can be completed without reducing the scanning speed as much as possible at the start of detachment. it can.

Further, the laser fusing method according to the present invention is such that the laser scanning trajectory is such that both the laser entry start position and the separation start position are located on a straight line region corresponding to a predetermined side of the product portion of the planned cutting line. May be set.

When the product part to be cut out has a shape having a side (for example, a rectangular shape), it is preferable to arrange the laser entry start position and the release start position on the straight line region of the planned cutting line corresponding to this side. By determining the scanning trajectory in this way, it is possible to easily set the laser scanning conditions such as the approach speed on the planned cutting line and the specific shape or size of the approach trajectory. In addition, since scanning conditions can be easily set, actual scanning can be easily performed with high accuracy. Therefore, it is possible to stably cut out a high-quality product part.

In addition, the laser fusing method according to the present invention draws an arc-shaped trajectory and starts the approach to the cutting line, the radius of the laser entering trajectory is R1, and draws an arc-shaped trajectory from the planned cutting line. When the radius of the laser separation locus to start is R2, the laser spot diameter is D, and the width dimension of the slit formed by melting the workpiece by laser irradiation is L, the distance from the entry start position to the separation start position The offset amount S may satisfy the following formula 1.

Preferably, the offset amount S may satisfy the following mathematical formula 2.

More preferably, the offset amount may satisfy Equation 3 below.

The present inventor specifically examined the relationship between the offset amount from the laser entry start position to the separation start position and various parameters related to the laser scanning conditions, and in particular, the laser entry drawing an arc-shaped locus. The radius R1 of the locus, the radius R2 of the separation locus, the laser spot diameter D, and the width L of the slit formed by melting the workpiece by laser irradiation are dominant to the offset amount S. found. As a result of further scrutiny and examination, it has been found that the range of the offset amount within which the peripheral shape of the product part can be tolerated can be calculated by the mathematical formula using the above parameters. The above formulas 1 to 3 are based on the above intensive studies. If the offset amount S is set within the range satisfying the above formula, the deformation amount (protrusion amount) from the peripheral portion of the product portion is determined as the product. The laser can be scanned (fused) at such a speed that the productivity can be maintained while suppressing the size so as not to cause a problem in the shape quality of the portion.

Further, in the laser fusing method according to the present invention, the product part may be a substantially rectangular plate glass.

As described above, the present invention suppresses excessive heating of the peripheral portion of the product portion in the vicinity of the laser entry start position, and makes it possible to prevent softening and deformation of the peripheral portion as much as possible. Since it is a thing, it can apply suitably for the plate-shaped glass product by which high shape quality is requested | required like a substantially rectangular plate glass.

The solution to the above problem can also be achieved by the sheet glass product according to the present invention. That is, this glass product is obtained by cutting a part or the whole of a plate-shaped workpiece from a non-product part by fusing, and in a plate-like glass product having one or more sides, a melted cross section generated by fusing Is formed along the side, and a protruding portion that protrudes toward the non-product portion side is formed on the molten cross section, and the maximum protrusion amount of the protruding portion toward the non-product portion side is 10 μm or more and 100 μm or less. Characterized with a certain point.

By restricting the size of the protruding portion within the above range, the sheet glass cut by fusing is provided as it is as a sheet glass product without subjecting the melted cross section formed along the side to end face processing such as polishing. It becomes possible.

Further, the plate-like glass product according to the present invention may have a length dimension in the direction along the side of the protrusion of 100 μm or more and 2000 μm or less, and in that case, the dimension of the protrusion in the plate thickness direction may be It may be larger in the range of 5 μm or more and 100 μm or less than the dimension in the thickness direction at the portion other than the protruding portion.

As described above, according to the present invention, it is possible to cut a product portion from a workpiece by laser cutting while ensuring shape quality. Moreover, when a product part is a plate glass product, it becomes possible to provide the plate glass cut | disconnected from the plate workpiece by fusing as it is as a plate glass product.

It is a schematic plan view of the laser cutting apparatus which concerns on one Embodiment of this invention. FIG. 2 is a cross-sectional view of the main part AA of the fusing device shown in FIG. It is a whole top view for demonstrating the scanning aspect of the laser which concerns on one Embodiment of this invention. It is a principal part top view of FIG. It is a figure for demonstrating an example of the laser fusing method using the fusing apparatus shown in FIG.1 and FIG.2, Comprising: It is a figure which shows the mode at the time of starting the irradiation of a laser. It is a figure for demonstrating an example of the laser fusing method using the fusing apparatus shown in FIG.1 and FIG.2, Comprising: It is a principal part enlarged view which shows a mode at the time of a laser approaching on a cutting projected line. It is a figure for demonstrating an example of the laser fusing method using the fusing apparatus shown in FIG.1 and FIG.2, Comprising: It is a figure which shows a mode that the laser is scanned along the cutting plan line. It is a figure for demonstrating an example of the laser fusing method using the fusing apparatus shown in FIG.1 and FIG.2, Comprising: It is a principal part enlarged view which shows a mode when a laser detaches | leaves from a cutting planned line. It is a figure for demonstrating an example of the laser fusing method using the fusing apparatus shown in FIG.1 and FIG.2, Comprising: It is a figure which shows a mode when the irradiation of a laser is complete | finished. It is a principal part enlarged view which shows the mode of the peripheral part of the product part cut out by the laser cutting method using the fusing apparatus shown in FIG. It is a whole top view for demonstrating the scanning aspect of the laser which concerns on other embodiment of this invention. It is a graph which shows the experimental result for demonstrating the effect of this invention. It is a schematic plan view for demonstrating the scanning aspect of the laser which concerns on cutting out of the sheet glass using the conventional laser fusing method. It is a principal part enlarged view which shows a mode when a laser detaches | leaves from the cutting planned line in the conventional scanning mode.

Hereinafter, an embodiment of the laser fusing method according to the present invention will be described with reference to FIGS. In the present embodiment, an example is described in which a sheet glass 1 formed by a predetermined method is a cutting object (work), and one or a plurality of sheet glass products (product part 2) are cut out from the sheet glass 1. I will explain to you. In addition, as the sheet glass 1 to which the laser fusing treatment is performed by the following method, a glass having a thickness of 10 μm or more and 500 μm or less is preferable, and a glass having a thickness of 10 μm or more and 300 μm or less is better. More preferably, the thickness is 200 μm or less. Moreover, the product part 2 cut out from the plate-like glass 1 is used, for example, as a cover material (protective cover) for a touch panel incorporated in a portable electronic device. In this embodiment, each rectangular part has a substantially rectangular shape. The cutout shape of the product part 2 (the shape of the planned cutting line 4 serving as the boundary between the product part 2 and the non-product part 3) is set so as to have a shape (rectangular shape).

FIG. 1 is a schematic plan view of a laser fusing device 10 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the main part AA of the laser fusing device 10. As shown in FIGS. 1 and 2, the laser fusing device 10 applies a fusing laser 11 to the plate glass 1 along a planned cutting line 4 (shown by a one-dot chain line in FIG. 1) of the plate glass 1. It mainly includes a laser irradiation device 12 for irradiation, an assist gas injection device 15 for injecting an assist gas 14 toward the irradiation region 13 of the laser 11, and a support base 16 for supporting the placed glass sheet 1. In FIG. 3 and subsequent figures, the laser irradiation device 12 and the assist gas injection device 15 are omitted in order to facilitate understanding of the scanning mode of the laser 11.

The laser irradiation device 12 includes at least an oscillator that is a generation source of a laser 11 typified by a carbon dioxide laser, a YAG laser, and the like, and a condenser lens (both not shown). The laser 11 can be irradiated at a predetermined angle (substantially vertical in the present embodiment). The irradiated laser 11 may be continuous light or pulsed light. Further, the output of the laser 11 is appropriately adjusted depending on the material and thickness of the sheet glass 1, the scanning speed of the laser 11, and the like.

In addition, although illustration is abbreviate | omitted, the laser fusing apparatus 10 which concerns on this invention was further equipped with the laser irradiation apparatus for slow cooling which irradiates the laser for slow cooling defocused in the predetermined | prescribed aspect toward the sheet glass 1 It may be. In this way, by irradiating the slow cooling laser to the front and rear of the irradiation region 13 of the laser 11 in the plate-like glass 1, in other words, toward the front and rear regions of the laser 11 in the scanning direction, This area can be heated in advance, and the area around the area immediately after fusing (melt cutting) can be continuously heated. Thereby, rapid cooling of the sheet glass 1 can be suppressed, and the occurrence of residual strain at the peripheral edge portion (cut end portion) of the product portion 2 can be prevented as much as possible.

The assist gas injection device 15 is configured to be able to inject the assist gas 14 toward the irradiation region 13 of the laser 11 in order to blow off the melt generated as the plate 11 is irradiated with the laser 11. The In the present embodiment, the assist gas injection device 15 is disposed above the region that becomes the product part 2 of the sheet glass 1, and the assist gas 14 is directed to the irradiation region 13 of the laser 11 from above the region that becomes the product part 2. An injection port is installed diagonally downward. Thereby, the melt generated in the cutting (melting) region of the sheet glass 1 is blown off toward the non-product part 3 side by the assist gas 14. Therefore, a situation in which a melt as a foreign matter adheres to the cut end face or the like of the product part 2 and a defective shape occurs in the product part 2 is prevented as much as possible. In addition, the kind of assist gas 14 which can be used is not specifically limited, For example, well-known gas, such as oxygen gas, water vapor | steam, carbon dioxide gas, nitrogen gas, argon gas, is used individually or in mixture of multiple types.

Of course, the injection mode of the assist gas injection device 15 is not limited to the above form. For example, although illustration is omitted, an assist gas injection device 15 may be arranged on the product portion 2 so that the assist gas 14 can be injected in a substantially horizontal direction with respect to the irradiation region 13 of the laser 11. Further, it is sufficient if the assist gas injection device 15 is provided as necessary, and it is not always necessary to provide it.

The support table 16 supports the glass sheet 1 to be cut in a horizontal posture from below. In the present embodiment, the first support portion 17 capable of supporting the region that becomes the substantially rectangular product portion 2, and the product It has the 2nd support part 18 which is located in the circumference | surroundings of the part 2 and can support the area | region used as the non-product part 3 of a hollow rectangular shape. The first support portion 17 and the second support portion 18 are separated by a groove portion 19. This groove portion 19 is provided under the scanning region of the laser 11 set in advance in a predetermined locus.

In addition, although illustration is abbreviate | omitted, even if the laser fusing apparatus 10 which concerns on this invention is further provided with the adsorption | suction means for enabling it to be supported by the support stand 16 in the state which adsorb | sucked the sheet glass 1 from the downward direction. Good. By providing such suction means and sequentially performing laser fusing (melting cutting) processing of the glass sheet 1 along the planned cutting line 4 in a state where the glass sheet 1 is sucked and supported by the support 16, The positional deviation of the glass 1 with respect to the support 16 can be prevented. Therefore, it is possible to improve the cutting accuracy and to cut out the high-quality product part 2.

Next, the scanning mode of the laser 11 will be described.

Scanning of the laser 11 is performed by moving the laser irradiation device 12 and the assist gas injection device 15 relative to the support table 16 and the plate-like glass 1 supported on the support table 16 in the horizontal direction. The scanning of the laser 11 is performed by irradiating the sheet glass 1 to be melted with the laser 11 and scanning the laser 11 along the planned cutting line 4 of the sheet glass 1 having a closed curve. The glass-like glass 1 is melted, and a locus capable of cutting out the product part 2 surrounded by the planned cutting line 4 from the plate-like glass 1 is drawn.

More specifically, as shown by a two-dot chain line in FIG. 3, the laser 11 causes the laser 11 to enter the planned cutting line 4 from the outside of the planned cutting line 4 when viewed from the product portion 2, and to the planned cutting line 4. After scanning along, a scanning trajectory 20 for taking the laser 11 away from the cutting line 4 to the outside is taken. In this case, the irradiation start position P1 of the laser 11 is the starting point of the scanning locus 20 (more precisely, the starting point of the center line of the scanning locus 20) and is set outside the planned cutting line 4 (on the non-product part 3 side). . Further, the irradiation end position P2 of the laser 11 is the end point of the scanning locus 20, and is set outside the planned cutting line 4 in the same manner as the irradiation start position P1. Note that the scanning trajectory 20 here indicates the trajectory formed by the irradiation region 13 of the laser 11 precisely, and is therefore displayed as a region having a certain width direction (region surrounded by a two-dot chain line). Has been. In the present embodiment, the scanning trajectory 20 (entrance locus 20a) of the laser 11 is set so that the laser 11 starts an approach on the planned cutting line 4 while drawing an arc-like locus. Further, the laser 11 is caused to enter the planned cutting line 4 so that the scanning trajectory of the laser 11 at the time of passing the approach start position P3 that starts entering the planned cutting line 4 is in contact with the planned cutting line 4 (approach trajectory). 20a is set).

Similarly, the scanning trajectory 20 (detachment locus 20b) of the laser 11 is set so that the laser 11 draws an arc-shaped locus and starts to leave from the planned cutting line 4 when leaving. Further, the laser 11 is separated from the planned cutting line 4 so that the scanning trajectory of the laser 11 when contacting the planned cutting line 4 when passing the separation starting position P4 where the separation from the planned cutting line 4 is started (separated trace). 20b is set).

Further, in the present embodiment, since the product part 2 has a substantially rectangular shape with rounded corners, the corresponding planned cutting line 4 also has a substantially rectangular shape with rounded corners. Therefore, the approach start position P3 and the exit start position P4 of the laser 11 are both on the straight region 4a along the predetermined side of the product portion 2 (here, the upper short side in FIG. 3) of the planned cutting line 4. The scanning trajectory 20 of the laser 11 is set so as to be positioned at.

When the scanning trajectory 20 as shown in FIG. 3 is taken, the scanning trajectory 20 intersects the straight line area 4 a of the planned cutting line 4. FIG. 4 is an enlarged view of the crossing portion of the scanning trajectory 20, and the separation start position P <b> 4 of the laser 11 from the planned cutting line 4 is set to be higher than the approach start position P <b> 3 of the planned cutting line 4. It is offset to the rear side in the scanning direction (left side as viewed from the entry start position P3 in FIG. 4).

Here, as shown in FIG. 4, the radius of the approach locus 20a of the laser 11 that starts the approach to the planned cutting line 4 while drawing an arc-like locus (more precisely, the radius of the center line of the approach locus 20a). R1 is also drawn in the same arc-shaped locus, and the radius of the separation locus 20b of the laser 11 that starts separation from the planned cutting line 4 (more precisely, the radius of the center line of the separation locus 20b) is defined as R2. The spot diameter (that is, the width direction dimension of the scanning region forming the scanning locus 20) is D, and the width dimension of the slit 21 (see FIG. 6 described later) formed by melting the glass sheet 1 by irradiation with the laser 11. When L is set to L, the offset amount S from the entry start position to the departure start position is preferably set so as to satisfy the above formula 1. Further, it is preferably set so as to satisfy the above formula 2, and more preferably set so as to satisfy the above formula 3.

Hereinafter, an example of a laser fusing method for the sheet glass 1 using the fusing device 10 having the above configuration will be described.

First, as shown in FIG. 5, the laser irradiation device 12 (indicated by a two-dot chain line in FIG. 5) is seen outside the planned cutting line 4 when viewed from the product part 2 of the sheet glass 1, that is, on the non-product part 3. It arrange | positions on the irradiation start position P1 located in the side. And while irradiating the laser 11 from the laser irradiation apparatus 12, while scanning the laser 11 along the scanning locus | trajectory 20 (arc-shaped approach locus | trajectory 20a in this step) preset as mentioned above, it is with respect to the sheet glass 1 Start laser fusing.

In this way, the laser 11 is scanned along the approach locus 20a while melting the non-product part 3 of the sheet glass 1, and enters the planned cutting line 4 (see FIG. 6). At this time, the laser 11 enters the cutting line 4 asymptotically to the cutting line 4 as shown in FIG. 6, and therefore enters the cutting line 4 while maintaining the scanning speed. can do.

In this way, by entering the planned cutting line 4 and scanning the laser 11 along the planned cutting line 4, the region including the planned cutting line 4 is melted, with the planned cutting line 4 as the center, and a plate shape Slits 21 penetrating the glass 1 in the front and back directions are sequentially formed along the planned cutting line 4 (see FIG. 7).

Thus, the laser 11 is scanned along the preset scanning trajectory 20, and after about one round around the product portion 2, the laser 11 starts to be detached from the planned cutting line 4 (see FIG. 8). At this time, as shown in FIG. 8, the laser 11 is separated from the planned cutting line 4 along an arc-shaped track (detached track 20 b) that contacts the planned cutting line 4 at the separation start position P <b> 4. Therefore, the laser 11 can be detached from the planned cutting line 4 while maintaining the scanning speed.

Then, the scanning of the laser 11 is continued along the scanning locus 20 (here, the separation locus 20b), and the laser irradiation device 12 is moved to the non-product part 3 side as shown in FIG. When 11 reaches the irradiation end position P2 on the non-product part 3, the irradiation of the laser 11 is ended. In this way, the cutting operation of the product portion 2 from the plate glass 1 by scanning with the laser 11 is completed.

Thus, in the present invention, the separation start position P4 of the laser 11 is offset to the rear side in the scanning direction of the laser 11 with respect to the entry start position P3. In other words, the laser 11 is detached from the planned cutting line 4 to the outside (the non-product part 3 side) as early as possible so that substantial cutting can be performed. Thereby, the area of the area | region where irradiation of the laser 11 overlaps among the peripheral parts of the product part 2 can be restrained small. Therefore, it is possible to suppress excessive heating of the peripheral portion of the product portion 2 particularly around the entry start position P3 or the separation start position P4 of the laser 11 and to prevent the peripheral portion from being softened or deformed as much as possible. It becomes. Therefore, it is possible to improve the end face shape accuracy of the side 2a of the product part 2 particularly related to the laser 11 entering and leaving.

FIG. 10 is an enlarged schematic view of a region closest to the entry start position P3 and the separation start position P4 of the laser 11 in the side 2a of the product portion 2 as a sheet glass product cut out by the laser fusing method according to the present invention. It is shown as an example. As shown in FIG. 10, in the vicinity of the entry start position P3 and the separation start position P4 of the side 2a (peripheral part) of the product part 2 cut out by the laser fusing method according to the present invention, along the side 2a by fusing. A protruding portion 2a1 protruding outward from the formed molten section (not shown) is seen, but the protruding degree (maximum protruding amount 2a1r described later) is slight. Further, the shape of the protruding portion 2a1 (for example, the ratio of the maximum protruding amount 2a1r to the length dimension 2a1l described later) is comparatively gentle. On the other hand, in the product part 2 cut out by the laser fusing method according to the conventional scanning locus (see FIGS. 13 and 14), as shown by the two-dot chain line in FIG. Part 2a1 'can be seen. This also shows that the end surface shape accuracy of the product part cut out by the laser fusing method according to the present invention is improved.

Here, the maximum protrusion amount 2a1r (FIG. 10) to the outside of the protrusion 2a1 is preferably 10 μm or more and 100 μm or less, more preferably 15 μm or more and 80 μm or less, and more preferably 20 μm or more. And it is more preferable that it is 60 micrometers or less. Further, the length dimension 2a1l (FIG. 10) in the direction along the side 2a of the protrusion 2a1 is preferably 100 μm or more and 2000 μm or less, more preferably 200 μm or more and 1500 μm or less, and more preferably 300 μm or more. And it is more preferable that it is 1000 micrometers or less. In addition, the dimension in the plate thickness direction (not shown) of the protrusion 2a1 is preferably larger than the dimension in the thickness direction at a portion other than the protrusion 2a1 in the range of 5 μm to 100 μm, preferably 10 μm to 90 μm. It is more preferable that it is large in the range, and it is more preferable that it is large in the range of 15 μm or more and 80 μm or less. By restricting the size of the protrusion 2a1 within the above range (especially when the product part 2 for the above-mentioned use is cut out from the above-described size of the sheet glass 1, the size of the protrusion 2a1 is set within the above-described preferable range. By restricting), the product part 2 can be provided as a product as it is without separately performing end face processing such as polishing.

Further, in the present embodiment, the laser 11 is formed such that the approach locus 20a of the laser 11 is asymptotic to the planned cutting line 4 and the scanning trace of the laser 11 when passing through the approach start position P3 is in contact with the planned cutting line 4. Since 11 is made to enter on the planned cutting line 4, the laser fusing can proceed while maintaining the scanning speed of the laser 11. Further, in the present embodiment, the laser 11 has a shape in which the separation locus 20b of the laser 11 gradually moves away from the planned cutting line 4, and the scanning track of the laser 11 when passing through the separation start position P4 is in contact with the planned cutting line 4. Since the laser beam is separated from the cutting line 4, the laser fusing can proceed while maintaining the scanning speed of the laser 11. Therefore, it becomes possible to further improve the cutout quality (shape quality) of the product part 2.

Further, in the present embodiment, the appropriate offset amount S is determined so as to satisfy any one of the above formulas 1 to 3, so that the cutting quality of the product part 2 can also be improved. At this time, the approach locus 20a on the planned cutting line 4 and the leaving locus 20b from the planned cutting line 4 are configured by arc regions, so that a mathematical formula (for example, the mathematical formula 1 described above) necessary for setting the offset amount S is formed. -3) can be easily derived and the accuracy thereof can be improved. Therefore, this also makes it possible to further improve the cutout accuracy.

As mentioned above, although one embodiment of the laser fusing method according to the present invention has been described, this fusing method can naturally take any form within the scope of the present invention.

For example, in the above embodiment, the case where the offset amount S of the separation start position P4 with respect to the approach start position P3 of the laser 11 is set so as to satisfy any of the above formulas 1 to 3 is exemplified. This offset amount S should be appropriately set according to the scanning trajectory 20 of the laser 11. Therefore, when taking a scanning locus 20 other than those shown in FIGS. 3 and 4, it is preferable to set an appropriate offset amount S in accordance with the scanning locus.

Moreover, in the said embodiment, both the approach start position P3 and the leaving start position P4 of the laser 11 are both the straight area | region 4a corresponding to the predetermined | prescribed side (for example, 2a shown in FIG. 10) of the product part 2 among the cutting projected lines 4. Although the case where the scanning trajectory 20 of the laser 11 is set so as to be positioned above is illustrated, of course, the scanning trajectory 20 of the laser 11 is set so that the approach start position P3 and the departure start position P4 are located in other regions. It doesn't matter. For example, in the form shown in the figure, the scanning trajectory 20 of the laser 11 is set so that the entry start position P3 and the separation start position P4 are positioned on the arc region corresponding to the arcuate corner of the product part 2. It is also possible to do.

Moreover, in the said embodiment, although the case where the part cut out from the sheet glass 1 becomes the product part 2 was illustrated, even if this invention is applied when the part cut out from the sheet glass 1 becomes a product part I do not care. In other words, as illustrated in FIG. 11, when the outside of the planned cutting line 4 is the product portion 2 and the inside is the non-product portion 3 (for example, a substantially rectangular hole with rounded corners is defined as the product portion. 2), the present invention may be applied. In this case, the laser 11 is located on the planned cutting line 4 from the inside of the planned cutting line 4 as viewed from the product part 2, in other words, from the non-product part 3 side which is an area closed by the planned cutting line 4. Then, after scanning along the planned cutting line 4, a trajectory for separating the laser 11 from the planned cutting line 4 to the inside (the non-product part 3 side) is taken. Further, at this time, the laser 11 scans in the scanning direction of the laser 11 from the separation start position P4 where the laser 11 starts to leave the planned cutting line 4 and from the approach start position P3 where the laser 11 starts entering the planned cutting line 4. Offset backward. As a result, as in the above embodiment, excessive heating of the peripheral portion of the product portion 2 around the entry start position P3 or the separation start position P4 of the laser 11 is suppressed, and the peripheral portion is softened and deformed as much as possible. Therefore, it is possible to improve the end face shape accuracy of the side 2a of the product part 2 related to the laser 11 entering and leaving.

Examples of the present invention will be described below. In the following description, components having the same functions or shapes as those of the above-described constituent elements are given the same reference numerals as those in the above embodiment, and redundant descriptions are omitted.

In this embodiment, the irradiation start position P1 reaches the entry start position P3, the radius R1 of the approach locus 20a of the laser 11 having an arc shape, and the separation start position P4 to the irradiation end position P2 to form an arc shape. The shape of the side 2a (see FIG. 10) of the product portion 2 when the radius R2 of the separation locus 20b of the laser 11 (both see FIG. 4) and the offset amount S are changed and evaluated.

The fusing conditions are as follows. First, as a common condition, OA-10G (thickness: 100 [μm]) manufactured by Nippon Electric Glass Co., Ltd. was used for the sheet glass 1 to be subjected to laser fusing. Further, regarding the laser 11 for fusing, the output is 9 [W], the spot diameter D is 130 [μm], the processing speed (scanning speed) is 10 [mm / s], and the laser 11 is irradiated to form a plate shape. The width L of the slit 21 melt-formed on the glass 1 was set to 60 [μm]. The injection amount of the assist gas 14 from the assist gas injection device 15 was set to 60 [l / min].

Further, the radius R1 of the entry locus 20a and the radius R2 of the departure locus 20b are both set to three types of 3, 5, and 10 [mm], and the offset amount S in each case is changed in several steps (for example, five steps). The end face shape in the vicinity of the entry start position P3 and the separation start position P4 of the side 2a of the product part 2 at the time of the evaluation was quantified and evaluated. Specifically, an area having a predetermined length (for example, 4 mm) along the longitudinal direction of the side 2a in the peripheral end portion of the side 2a is set as a measurement target, and the measurement target is normal to the surface of the product part 2 using a microscope. An enlarged photograph of the measurement object was obtained by shooting from the direction. Thereafter, the position of the tip of the side 2a of the product part 2 is measured at regular intervals (for example, 50 μm) using the line obtained by connecting the longitudinal end positions of this region as a reference line, and the outside (non-product part) 3) and the deviation of the amount of protrusion to the outside in the above-mentioned region (the unit is μm).

Fig. 12 shows the experimental results. In FIG. 12, the solid plot indicates the maximum protrusion amount 2a1r, and the white plot indicates the deviation. Further, the offset amount S is standardized based on Formulas 1 to 3 (the offset rate is used). As shown in the figure, the maximum value of the protruding portion 2a1 (maximum protruding amount 2a1r) tends to decrease as the offset rate becomes larger than 0% regardless of the sizes of the radii R1 and R2. Okay (same for deviation). In addition, the offset rate (offset amount S) varies to some extent depending on the set radii R1 and R2, but has an optimum range to some extent. Specifically, it is preferably over 0% and less than 125%. , More than 25% and less than 100%, better than 40% and less than 70%.

DESCRIPTION OF SYMBOLS 1 Sheet glass 2 Product part 3 Non-product part 4 Planned cutting line 10 Laser cutting apparatus 11 Laser 12 Laser irradiation apparatus 13 Irradiation area 14 Assist gas 15 Assist gas injection apparatus 16 Support stand 20 Scanning locus

20a Entrance locus

20b Departure locus 21 Slit D Spot diameter (laser)
L width dimension (slit)
P1 Irradiation start position P2 Irradiation end position P3 Approach start position P4 Release start position S Offset amount 2a1r Maximum protrusion amount 2a1l of the protruding portion Length dimension in the direction along the side of the protruding portion

Claims

By irradiating a part or the whole of a plate-shaped workpiece with a laser and scanning the laser along a planned cutting line of the workpiece that is a closed curve, the workpiece is melted to obtain a product. A laser fusing method that divides a part into a non-product part,
After entering the laser on the planned cutting line from the non-product part side, and scanning along the planned cutting line, take a trajectory to detach the laser from the planned cutting line to the non-product part side,
The departure start position at which the laser starts to leave the planned cutting line is offset from the approach start position at which the laser starts to enter the planned cutting line to the rear side in the scanning direction of the laser, Laser fusing method to do.
In the case of cutting the product part surrounded by the planned cutting line from the workpiece by scanning the laser along the planned cutting line and melting the workpiece,
The laser enters the cutting line from the side of the non-product portion located outside the planned cutting line, scans along the planned cutting line, and then scans the laser from the planned cutting line. The laser fusing method according to claim 1, wherein a locus to be separated toward the non-product part is taken.
By scanning the laser along the planned cutting line and melting the workpiece, when obtaining the product part hollowed out the region surrounded by the planned cutting line,
The laser makes the laser enter the planned cutting line from the non-product portion side located inside the planned cutting line, scans along the planned cutting line, and then scans the laser from the planned cutting line. The laser fusing method according to claim 1, wherein a locus to be separated toward the non-product part is taken.
The laser fusing method according to any one of claims 1 to 3, wherein the laser enters the planned cutting line so that a scanning trajectory of the laser when passing through the entry start position is in contact with the planned cutting line.
The laser fusing method according to any one of claims 1 to 4, wherein the laser is separated from the planned cutting line so that a scanning trajectory of the laser when passing the separation start position is in contact with the planned cutting line.
The laser fusing method according to any one of claims 1 to 5, wherein the laser is scanned so that the laser draws an arc-shaped trajectory and starts entering the planned cutting line.
The laser fusing method according to any one of claims 1 to 6, wherein the laser is scanned so that the laser draws an arc-shaped trajectory and starts to be detached from the planned cutting line.
The laser scanning trajectory is set so that both the entry start position and the separation start position of the laser are located on a straight line region corresponding to a predetermined side of the product portion of the planned cutting line. 8. The laser fusing method according to any one of 1 to 7.
R1 is the radius of the laser entering locus that starts to enter the planned cutting line by drawing an arc-shaped locus, and R1 of the laser leaving locus that starts to leave from the planned cutting line by drawing an arc-shaped locus. When the radius is R2, the spot diameter of the laser is D, and the width dimension of the slit formed by melting the workpiece by laser irradiation is L, the offset amount from the entry start position to the release start position The laser fusing method according to claim 8, wherein S satisfies Formula 1.
R1 is the radius of the laser entering locus that starts to enter the planned cutting line by drawing an arc-shaped locus, and R1 of the laser leaving locus that starts to leave from the planned cutting line by drawing an arc-shaped locus. When the radius is R2, the spot diameter of the laser is D, and the width dimension of the slit formed by melting the workpiece by laser irradiation is L, the offset amount from the entry start position to the release start position The laser fusing method according to claim 8, wherein S satisfies Formula 2.
R1 is the radius of the laser entering locus that starts to enter the planned cutting line by drawing an arc-shaped locus, and R1 of the laser leaving locus that starts to leave from the planned cutting line by drawing an arc-shaped locus. When the radius is R2, the spot diameter of the laser is D, and the width dimension of the slit formed by melting the workpiece by laser irradiation is L, the offset amount from the entry start position to the release start position The laser fusing method according to claim 8, wherein S satisfies Formula 3.
The laser fusing method according to any one of claims 1 to 11, wherein the product part is a substantially rectangular plate glass.
In a plate-shaped glass product having one or more sides obtained by cutting a part or the whole of a plate-shaped workpiece from a non-product part by fusing,
A melted cross section generated by fusing is formed along the side, and a protrusion that protrudes toward the non-product part is formed on the melt cross section.
A plate-like glass product, wherein the maximum protruding amount of the protruding portion toward the non-product portion is 10 μm or more and 100 μm or less.
The length dimension in the direction along the side of the protrusion is not less than 100 μm and not more than 2000 μm, and the dimension in the thickness direction of the protrusion is 5 μm or more than the dimension in the thickness direction in the portion other than the protrusion, and The plate-like glass product according to claim 13, which is large in a range of 100 µm or less.