JP2014161899A - Laser working device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser working device for irradiating a substrate with a laser beam of a generally homogeneous intensity without performing any complex control.SOLUTION: A laser working device 10 comprises a laser oscillator 2, a polygon mirror 5 and a shield plate 7. The laser oscillator 2 outputs a laser beam. The polygon mirror 5 is driven to reflect the laser beam from the laser oscillator 2 toward a glass substrate G and to scan the laser beam repeatedly over a predetermined length L1 along a parting-scheduled line. The shield plate 7 shields any of the laser beams reflected by the polygon mirror 5 that corresponds to both end portions of the predetermined length L1.

Description

  The present invention relates to a laser processing apparatus.

  A laser processing apparatus is used to cut a substrate such as glass. A laser processing apparatus irradiates a laser beam along the dividing line of a board | substrate, and forms a scribe groove | channel on a board | substrate. Thereafter, the cutting device cuts the substrate along the scribe grooves.

  A laser processing apparatus generally includes a laser oscillator, an upper lens, and a lower lens, and a laser beam applied to the substrate has a predetermined length along the scanning direction. The intensity of the laser beam irradiated on the substrate is preferably uniform over a predetermined length. For example, the intensity of the laser beam is uniform over a predetermined length by using a specially processed lower lens. be able to. A laser beam having a uniform intensity over a predetermined length is generally called a top hat beam.

  However, when the top hat beam is formed using the lower lens specially processed as described above, the following problems occur. For example, if the lower lens is moved upward or downward in order to change the length of the top hat beam, the intensity at both ends in the length direction becomes non-uniform and the top hat beam is not produced.

  Therefore, for example, Patent Document 1 discloses that a polygon mirror is used and laser beam output timing is controlled based on rotational phase information of the polygon mirror, thereby suppressing unevenness in the intensity of the laser beam in the long axis direction. ing.

Japanese Patent No. 4549996

  The rotation of the polygon mirror is generally very high speed, and it is very difficult to perform various controls based on the rotation phase information of the polygon mirror as in the laser processing apparatus of Patent Document 1 described above.

  An object of the present invention is to irradiate a substrate with laser light having a substantially uniform intensity without complicated control.

  (1) A laser processing apparatus according to an aspect of the present invention is a laser processing apparatus that irradiates a laser beam along a line to be cut of a substrate, and includes a laser oscillator, a scanning member, and a shielding member. The laser oscillator outputs laser light. The scanning member is driven so as to reflect the laser beam from the laser oscillator toward the substrate and to repeatedly scan the laser beam over a predetermined length along a line to be divided. The shielding member shields laser light corresponding to both end portions of a predetermined length among the laser light reflected by the scanning member.

  According to this configuration, the laser beam is repeatedly scanned over a predetermined length by the scanning member. Of the laser light repeatedly scanned over this predetermined length, the intensity of the laser light corresponding to both ends of the predetermined length is higher or lower than the laser light corresponding to the other portions. Tends to be non-uniform. On the other hand, the laser processing apparatus mentioned above shields the laser beam corresponding to the both ends of a predetermined length with a shielding member. For this reason, it is possible to irradiate the substrate with laser light having a substantially uniform intensity without performing complicated control.

  (2) The scanning member may be a polygon mirror that repeatedly scans the laser beam by being driven to rotate.

  Since the polygon mirror has a plurality of mirror surfaces and reflects the laser beam toward the substrate while rotating, the laser beam can be repeatedly scanned over a predetermined length. This polygon mirror divides and reflects the laser light at the boundary between adjacent mirror surfaces. For this reason, the intensity of the laser beam reflected at the boundary of the polygon mirror is lowered. The laser beam reflected at the boundary of the polygon mirror corresponds to both end portions of a predetermined length. On the other hand, since the shielding member shields the laser beam corresponding to both ends of the predetermined length, the substrate can be irradiated with only the laser beam having a substantially uniform intensity without performing complicated control. .

  (3) The scanning member may be a mirror that repeatedly scans the laser beam by being reciprocally driven along a planned dividing line.

  The reciprocating mirror has a velocity of zero at the reciprocal turning point. For this reason, the laser beam reflected at this turning point is irradiated on the substrate for a longer time than the laser beam reflected at other positions. That is, the intensity of the laser light reflected at the turn-back point is higher than the intensity of the laser light reflected at other points. The laser beam reflected at the turning point corresponds to both end portions of a predetermined length. On the other hand, since the shielding member shields the laser beam corresponding to both ends of the predetermined length, the substrate can be irradiated with only the laser beam having a substantially uniform intensity without performing complicated control. .

  (4) The scanning member may be a mirror that repeatedly scans the laser light by being repeatedly driven to swing so as to change the reflection angle of the laser light.

  The mirror that is repeatedly driven to swing has a swing speed of zero when the swing angle, which is an angle formed with respect to the horizontal direction, is maximum and minimum. For this reason, the laser beam reflected at the maximum and minimum swing angles is irradiated on the substrate for a longer time than the laser beam reflected at other swing angles. That is, the intensity of the laser beam reflected at the maximum and minimum oscillation angles is higher than the intensity of the laser beam reflected at other oscillation angles. The laser beam reflected at the maximum and minimum swing angles corresponds to both end portions of a predetermined length. On the other hand, since the shielding member shields the laser light corresponding to both ends of the predetermined length, the substrate is irradiated with only the laser light having a substantially uniform intensity without performing complicated control.

  According to the present invention, it is possible to irradiate a substrate with laser light having a substantially uniform intensity without complicated control.

The schematic block diagram of a laser processing apparatus. The figure which shows typically distribution of the intensity | strength in the length direction of the laser beam irradiated to a glass substrate with a laser processing apparatus. The schematic block diagram of the laser processing apparatus which concerns on the modification 1. FIG. The figure which shows typically intensity distribution in the length direction of the laser beam irradiated to a glass substrate by the laser processing apparatus which concerns on the modification 1. As shown in FIG. The schematic block diagram of the laser processing apparatus which concerns on the modification 2. FIG. The figure which shows typically intensity distribution in the length direction of the laser beam irradiated to a glass substrate by the laser processing apparatus which concerns on the modification 2. As shown in FIG.

  Hereinafter, an embodiment of a laser processing apparatus 10 according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a laser processing apparatus 10.

(Configuration of laser processing equipment)
As shown in FIG. 1, the laser processing apparatus 10 includes a table 1, a laser oscillator 2, a lens 3, a mirror 4, and a polygon mirror (an example of a scanning member) 5. The lens 3, the mirror 4, and the polygon mirror 5 are accommodated in the cover 6.

  The table 1 is a member on which a glass substrate G to be processed is placed. A table driving mechanism (not shown) is provided so that the table 1 moves on the X and Y planes. In addition, the glass substrate G is mounted on the table 1 so that the division | segmentation planned line may face the X direction. The X direction indicates the left-right direction in FIG. 1, and the Y direction indicates the direction perpendicular to the paper surface of FIG.

The laser oscillator 2 is a device that outputs laser light, and outputs, for example, a CO ₂ laser (carbon dioxide laser). The laser oscillator 2 outputs a Gaussian beam as laser light. That is, the intensity of the laser beam output from the laser oscillator 2 exhibits a Gaussian distribution. The laser oscillator 2 is supported above the table 1 by a support frame (not shown).

  A lens 3 is installed below the laser oscillator 2. The lens 3 is a spherical plano-convex lens and condenses the laser light output from the laser oscillator 2. The lens 3 can change the width of the laser beam (the length in the Y direction) by moving in the vertical direction. A moving mechanism 3a for moving the lens 3 in the vertical direction is provided. The moving mechanism 3a moves the lens 3 up and down using, for example, a motor as a drive source.

  A mirror 4 is installed below the lens 3. The mirror 4 is a member for reflecting the laser beam output from the laser oscillator 2 and collected by the lens 3 and guiding it to the polygon mirror 5. A moving mechanism 4a for moving the mirror 4 in the vertical direction is provided. The moving mechanism 4a raises and lowers the mirror 4 using, for example, a motor as a drive source.

  The polygon mirror 5 has a polygonal shape and has a plurality of (for example, six) mirror surfaces 5a. The polygon mirror 5 reflects the laser light from the mirror 4 and guides it to the glass substrate G. The polygon mirror 5 is driven to rotate clockwise around a rotation shaft 5b by a motor (not shown). Although not particularly limited, the polygon mirror 5 rotates several tens of thousands per minute.

  A moving mechanism 5c for moving the polygon mirror 5 in the vertical direction is provided. The moving mechanism 5c moves the polygon mirror 5 up and down using, for example, a motor as a drive source. The adjustment in the vertical direction of the polygon mirror 5 is performed independently of the adjustment in the vertical direction of the mirror 4, but may be performed integrally. That is, the polygon mirror 5 and the mirror 4 may be configured to move up and down simultaneously by one operation.

  The cover 6 is a rectangular parallelepiped member having a space inside, and accommodates the lens 3, the mirror 4, and the polygon mirror 5. The cover 6 has a first opening 6a at the top and a second opening 6b at the bottom. Laser light output from the laser oscillator 2 enters the lens 3 through the first opening 6a. The first opening 6 a has an opening area that does not shield the laser beam from the laser oscillator 2. The laser light reflected by the polygon mirror 5 enters the glass substrate G through the second opening 6b. The second opening 6b has an opening area that does not shield the laser light reflected by the polygon mirror 5.

  Two shielding plates (an example of a shielding member) 7 are provided below the cover 6. Each shielding plate 7 shields a part of the laser light sent from the polygon mirror 5 to the glass substrate G through the second opening 6b. Specifically, the two shielding plates 7 are installed so as to cover both ends of the second opening 6b in the X direction so as to shorten the length of the second opening 6b in the X direction. Each shielding plate 7 defines a third opening 7a having a shorter length in the X direction than the second opening 6b. Each shielding plate 7 is movable in the X direction so that the length of the third opening 7a in the X direction can be changed. Each shielding plate 7 is formed of a metal plate coated with a carbon resin so as to absorb laser light.

(Operation of laser processing equipment)
Next, the operation of the above-described laser processing apparatus 10 will be described.

  First, the laser oscillator 2 outputs laser light whose intensity has a Gaussian distribution. Laser light from the laser oscillator 2 enters the lens 3 through the first opening 6a. The laser light is collected at the lens 3. The condensed laser light is reflected by the mirror 4 and proceeds to the polygon mirror 5. In addition, it is preferable to adjust the angle of the mirror 4 so that the incident angle and the reflection angle of the laser beam at the mirror 4 at this time are about 45 degrees.

  The polygon mirror 5 reflects the laser light from the mirror 4 to the glass substrate G while rotating clockwise. The polygon mirror 5 reflects the laser beam at each mirror surface 5a. Since the polygon mirror 5 rotates, the incident angle and reflection angle of the laser beam at the polygon mirror 5 change. As a result, as shown in FIG. 2, the polygon mirror 5 repeatedly scans the laser light on the glass substrate G over a predetermined length L <b> 1 along the planned division line. FIG. 2 is a diagram schematically showing the intensity distribution in the length direction of the laser light irradiated to the glass substrate G by the laser processing apparatus 10. The two-dot chain line portion in FIG. 2 indicates the laser light that is not actually irradiated onto the glass substrate G and its intensity distribution.

  The shielding plate 7 shields a part of the laser light reflected by the polygon mirror 5. Specifically, the shielding plate 7 shields the laser light corresponding to both end portions of the predetermined length L1. In addition, the laser beam reflected by the boundary part 5d of the mirror surface 5a adjacent to the polygon mirror 5 is a laser beam corresponding to both ends of the predetermined length L1. In this way, the shielding plate 7 shields the laser light corresponding to both ends of the predetermined length L1, so that the length L2 of the laser light actually irradiated to the glass substrate G is set at the both ends of the predetermined length L1. Excluded.

[Feature]
The laser processing apparatus 10 according to the present embodiment has the following characteristics.

  Since the polygon mirror 5 divides and reflects the laser beam at the boundary portion 5d between the adjacent mirror surfaces 5a, the intensity of the laser beam reflected at the boundary portion 5d is lowered. The laser light reflected by the boundary portion 5d of the polygon mirror 5 corresponds to both end portions of the predetermined length L1. On the other hand, since the shielding plate 7 shields the laser beams corresponding to both ends of the predetermined length L1, the glass substrate G is irradiated only with a laser beam having a substantially uniform intensity without performing complicated control. can do.

[Modification]
As mentioned above, although embodiment of this invention was described, this invention is not limited to these, A various change is possible unless it deviates from the meaning of this invention.

Modification 1
FIG. 3 is a schematic configuration diagram of a laser processing apparatus 11 according to the first modification. As shown in FIG. 3, the laser processing apparatus 11 according to the first modification includes a mirror 15 that is driven to reciprocate along a planned dividing line, instead of the polygon mirror 5. The mirror 15 reflects the laser light from the mirror 4 and guides it to the glass substrate G through the third opening 7a.

  The laser processing apparatus 11 further includes a reciprocating drive mechanism 16 for reciprocating the mirror 15. The reciprocating drive mechanism 16 includes a rotating disk 16a and a connection arm 16b. The rotating disk 16a is driven to rotate about a rotating shaft 16c by a motor (not shown). The connection arm 16b connects the outer peripheral edge of the rotary disk 15a and the mirror 15. Each end of the connection arm 15b and the mirror 15 or the rotating disk 15a are coupled to freely rotate. As the rotating disk 15a rotates, the mirror 15 is driven to reciprocate along the X direction, that is, along the planned dividing line of the glass substrate G. The angle of the mirror 15 is fixed, and preferably the angle of the mirror 15 is 45 degrees with respect to the horizontal direction. The mirror 15 is reciprocally driven along the planned dividing line, thereby repeatedly scanning the laser beam over a predetermined length L1.

  FIG. 4 is a diagram schematically illustrating the intensity distribution in the length direction of the laser light irradiated onto the glass substrate G by the laser processing apparatus 11 according to the first modification. As shown in FIG. 4, the reciprocating mirror 15 has a velocity of zero at the reciprocal turning point. Specifically, the mirror 15 reciprocates between the regions A, and the velocity once becomes zero at the left end A1 and the right end A2 of the region A. For this reason, the intensity of the laser beam reflected when the mirror 15 is at the reciprocal folding points A1 and A2 is higher than the intensity of the laser beam reflected when the mirror 15 is at another position. The laser light reflected when the mirror 15 is at the reciprocating folding points A1 and A2 is laser light corresponding to both end portions of the predetermined length L1. And the shielding board 7 is installed so that the laser beam corresponding to the both ends of this predetermined length L1 may be shielded. As a result, it is possible to irradiate the glass substrate G only with laser light having a substantially uniform intensity.

Modification 2
FIG. 5 is a schematic configuration diagram of a laser device 12 according to the second modification. As shown in FIG. 5, the laser processing apparatus 12 according to Modification 2 includes a mirror 25 that is driven to swing instead of the polygon mirror 5. The mirror 25 reflects the laser light from the mirror 4 and guides it to the glass substrate G through the third opening 7a. The mirror 25 is driven to swing around a swing 25a by a motor (not shown).

  FIG. 6 is a diagram schematically illustrating the intensity distribution in the length direction of the laser light irradiated onto the glass substrate G by the laser processing apparatus 12 according to the second modification. As shown in FIG. 6, the mirror 25 is repeatedly oscillated between oscillating angles α1 to α2 in the horizontal direction, thereby changing the reflection angle of the laser beam. As a result, the mirror 25 repeatedly scans the laser beam over a predetermined length L1.

  The mirror 25 has a swing speed of zero when the swing angle is maximum and minimum. Specifically, the swing speed of the mirror 25 becomes zero when the swing angle becomes the minimum swing angle α1 and the maximum swing angle α2. Therefore, the intensity of the laser beam reflected when the mirror 25 reaches the minimum oscillation angle α1 and the maximum oscillation angle α2 is higher than the intensity of the laser beam reflected when the mirror 25 reaches another oscillation angle. Become. The laser beam reflected when the mirror 25 reaches the minimum and maximum swing angles α1 and α2 is a laser beam corresponding to both end portions of the predetermined length L1. And the shielding board 7 is installed so that the laser beam corresponding to the both ends of this predetermined length L1 may be shielded. As a result, it is possible to irradiate the glass substrate G only with laser light having a substantially uniform intensity.

Modification 3
In the said embodiment and each modification, although the shielding board 7 is a member different from the cover 6, it is not specifically limited to this, The shielding board 7 may be integrally formed with the cover 6. FIG.

Modification 4
Although the shielding member in the said embodiment and each modification is comprised from the two shielding boards 7, it is not limited to this in particular, What is necessary is just a member which shields the laser beam corresponding to the both ends of predetermined length L1. . For example, it may be a single shielding plate having a third opening 7a that shields laser light corresponding to both ends of the predetermined length L1.

Modification 5
In the above embodiment and each modified example, the laser light from the laser oscillator 2 is indirectly incident on the scanning member such as the polygon mirror 5 or the mirrors 15 and 25 via the lens 3 and the mirror 4. It is not limited. For example, the laser light from the laser oscillator 2 may be incident on the scanning members 5, 15, and 25 only through the lens 3, or may be directly incident on the scanning members 5, 15, and 25 without intervening anything. Also good.

2 Laser oscillator 5 Polygon mirror (scanning member)
7 Shield plate (shield member)
10, 11, 12 Laser processing device 15, 25 Mirror (scanning member)

Claims (5)

A laser processing apparatus for irradiating a laser beam along a planned dividing line of a substrate,
A laser oscillator that outputs laser light;
A scanning member that is driven to reflect laser light from the laser oscillator toward the substrate and to repeatedly scan the laser light over a predetermined length along the dividing line;
A shielding member that shields laser light corresponding to both ends of the predetermined length of the laser light reflected by the scanning member;
A laser processing apparatus comprising:   The laser processing apparatus according to claim 1, wherein the scanning member is a polygon mirror that repeatedly scans the laser light by being driven to rotate.   2. The laser processing apparatus according to claim 1, wherein the scanning member is a mirror that repeatedly scans the laser light by being reciprocated along the division planned line. 3.   The laser processing apparatus according to claim 1, wherein the scanning member is a mirror that repeatedly scans the laser light by being repeatedly oscillated to change the reflection angle of the laser light.   The laser processing apparatus according to claim 1, wherein the laser oscillator outputs a Gaussian beam as the laser light.

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