KR101886357B1 - Method for detecting laser beam spot shape and apparatus for detecting laser beam spot shape - Google Patents

Abstract

SUMMARY OF THE INVENTION An object of the present invention is to provide a laser beam spot and shape detection method capable of accurately detecting a spot shape and a light-converging point position (focal distance) of a laser beam.
The present invention relates to a spot shape detection method of a laser beam which is generated by a laser beam oscillation means and detects a spot shape of a laser beam condensed by a condenser, (Z-axis) orthogonal to the Z-axis direction and a Y-axis direction orthogonal to the X-axis direction and the Z-axis direction on the optical axis (Z-axis) of the laser beam focused by the condenser A laser beam irradiating step of converging and irradiating a laser beam of an output which can not process the transparent substrate on the region where the fine prism formed on the transparent substrate is positioned by the condenser, In the X-axis direction and the Y-axis direction relative to the condenser in a state in which the laser beam is irradiated on the transparent substrate A light intensity detecting step of detecting the light intensity of the light refracted by the fine prism formed on the transparent substrate while moving the light intensity detecting means; and a light intensity detecting step of detecting the light intensity in the x, y coordinate values of the fine prism detected in the light intensity detecting step And a light intensity map creation step of creating an intensity map, wherein the light intensity detection step and the light intensity map creation step are performed at a plurality of detection positions in the Z axis direction in the light concentrator, And a spot shape image forming step of creating a spot shape image of the laser beam based on the light intensity map of the spot shape image.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spot shape detecting method and spot shape detecting apparatus for detecting a spot shape of a laser beam,

The present invention relates to a spot shape detection method and spot shape detection device for detecting a spot shape of a laser beam emitted from a laser beam oscillation means of a laser processing machine and condensed by a condenser.

In the semiconductor device manufacturing process, a plurality of regions are defined by a line to be divided which is formed in a lattice pattern on the surface of a semiconductor wafer which is substantially in a disk shape, and devices such as ICs and LSIs are formed in the divided regions. The semiconductor wafer thus formed is cut along the line to be divided so that the area where the device is formed is divided to manufacture individual devices. In addition, an optical device wafer in which a sapphire substrate or a silicon carbide substrate is laminated with a gallium nitride compound semiconductor or the like is also divided along an expected line to be divided into optical devices such as individual light emitting diodes and laser diodes, .

As a method of dividing the above-described wafer along a line to be divided, a laser machining groove serving as a starting point of fracture is formed by irradiating a wafer with a pulsed laser beam of a wavelength having a water absorbing property along a line to be divided, (See, for example, Japanese Patent Application Laid-Open No. 2001-3258).

As a method of dividing the wafer along the line to be divided along the line to be divided, a pulse laser beam of a wavelength having a transmittance with respect to the wafer is used, and a laser beam process for irradiating a pulsed laser beam with a light- Methods have also been tried. In this dividing method using the laser processing method, a condensing point is set inward from one side of a wafer, a pulsed laser beam of a wavelength having a transmittance to the wafer is irradiated to the wafer, and a modified layer is continuously formed And the external force is applied along the streets where the strength is lowered by forming the modified layer, thereby breaking the wafer and dividing the wafer. (See, for example, Patent Document 2).

However, since the condenser for condensing the laser beam is composed of a combination lens in which a plurality of convex lenses and a concave lens are combined, and the optical system from the laser oscillator to the condenser is distorted, Is not condensed into the intended shape of the light source. It is determined that the shape of the focused spot of the laser beam and the size of the focused spot have an influence on the processing quality. For this reason, the spot shape of the laser beam irradiated on the workpiece such as a wafer and the size of the focused spot are detected.

Patent Document 1: JP-A-10-305420 Patent Document 2: Japanese Patent No. 3408805

Thus, the detection of the spot shape and the position of the light-converging point of the laser beam irradiated on the workpiece such as a wafer is performed by, for example, locating a laser beam spot on an opaque glass and imaging the spot from the back surface with a CCD camera However, there is a problem that the accurate spot shape and the position of the light-converging point can not be detected by the scattered light of the opaque glass.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is a main object of the present invention to provide a spot shape detection method of a laser beam capable of accurately detecting a spot shape of a laser beam and a focal point position (focal distance).

According to the present invention, there is provided a spot shape detection method of a laser beam which is generated by a laser beam oscillation means and detects a spot shape of a laser beam condensed by a condenser,

A transparent substrate having fine prisms smaller than the size of the condensing spot formed on its surface is placed on the optical axis (Z-axis) of the laser beam condensed by the condenser in the X-axis direction orthogonal to the Z-axis direction and in the Z- A transparent substrate positioning step of positioning the substrate in a Y-

A laser beam irradiation step of condensing and irradiating a laser beam of an output which can not process the transparent substrate on the region where the fine prism formed on the transparent substrate is located,

A transparent prism is formed on the transparent substrate by moving the transparent substrate in the X-axis direction and the Y-axis direction relative to the light condenser while irradiating a laser beam on a region where the fine prisms formed on the transparent substrate are located, A light intensity detecting step of detecting light intensity by light intensity detecting means;

And a light intensity map creating step of creating a light intensity map in x, y coordinate values of the fine prism detected in the light intensity detecting step,

The light intensity detecting step and the light intensity map forming step are performed at a plurality of detection positions in the Z axis direction of the condenser, A spot shape image forming step of forming a spot shape image; and a display step of displaying a spot shape image created by the spot shape image forming step on the display means,

The spot shape of the laser beam is detected.

Further, according to the present invention, there is provided a spot shape detecting apparatus for a laser beam which detects a spot shape of a laser beam emitted by a laser beam emitting means and condensed by a light-

A transparent substrate provided on an optical axis (Z-axis) of the laser beam condensed by the condenser and having a size smaller than the size of the condensing spot formed on the surface thereof, and a transparent substrate on which the transparent substrate is moved in the X- Axis direction moving means for moving the transparent substrate in the Y-axis direction orthogonal to the Z-axis direction and the X-axis direction; Z-axis direction moving means for moving the condenser in the Z-axis direction; Axis direction position detecting means for detecting a position of the fine prism formed on the transparent substrate in the Y-axis direction, and a position detecting means for detecting a position of the fine prism formed on the transparent substrate, Z-axis direction position detecting means for detecting a Z-axis direction position, light intensity detecting means for detecting light intensity of light refracted by the fine prism formed on the transparent substrate, A control means for obtaining a spot shape of the laser beam based on light detection means, detection signals from the X-axis direction position detection means, the Y-axis direction position detection means and the Z-axis direction position detection means, And display means for displaying the spot shape of the laser beam obtained by the above-

Wherein the control means controls the laser beam irradiation step of operating the laser beam emission means to focus the laser beam on the region where the fine prism formed on the transparent substrate is located, Axis direction moving means and the Y-axis direction moving means in a state in which a laser beam is irradiated to a region where the fine prism formed on the transparent substrate is positioned, thereby to move the transparent substrate in the X- A light intensity detecting step of detecting the light intensity of the light refracted by the fine prism formed on the transparent substrate by the light intensity detecting means while moving in the Y axis direction; A light intensity map creating step of creating a light intensity map in the coordinate value, And a light intensity map forming step is carried out at a plurality of detection positions in the direction of the light intensity map in the light intensity map forming step and a spot shape image of the laser light beam is generated based on the plurality of light intensity maps created in the light intensity map forming step And a display step of displaying a spot shape image created by the spot shape image forming step on the display means,

And a laser beam spot shape detecting device for detecting a spot shape of the laser beam.

The transparent substrate is made of a quartz substrate, and the fine prisms are formed on a quartz substrate.

The light intensity detecting means comprises an imaging lens positioned on the optical axis of the light refracted by the fine prism formed on the transparent substrate and a photodetector for capturing the light imaged by the imaging lens.

In the spot shape detecting method and the spot shape detecting apparatus of the present invention, the transparent substrate on which the fine prisms smaller in size than the focused spot are formed on the optical axis (Z axis) of the laser beam condensed by the concentrator A Z-axis direction orthogonal to the Z-axis direction, and a Y-axis direction orthogonal to the Z-axis direction and the Y-axis direction orthogonal to the Z-axis direction; A laser beam irradiation step of condensing and irradiating a laser beam having an output that can not process the transparent substrate by the condenser; and a step of irradiating the transparent substrate with a laser beam on a region where the fine prism formed on the transparent substrate is positioned, While being relatively moved in the X-axis direction and the Y-axis direction, refracted by the fine prisms formed on the transparent substrate A light intensity detecting step of detecting the light intensity of light by the light intensity detecting means and a light intensity map generating step of producing a light intensity map in the x and y coordinate values of the fine prism detected in the light intensity detecting step And a light intensity detecting step and a light intensity map forming step are carried out at a plurality of detection positions in the Z axis direction in the light concentrator, and the spot shape of the laser beam based on the plurality of light intensity maps created in the light intensity map forming step And a display step of displaying the spot-shaped image created by the spot-shaped image forming step on the display means. Therefore, it is possible to prevent the outline (spot Shape) can be obtained. A spot having a minimum size (area) of the spot detected at a plurality of detection positions in the direction of the optical axis (Z-axis) of the laser beam becomes a light focusing spot, and the size (area) of the light focusing spot can be obtained , The focal distance of the condenser can be obtained accurately.

1 is a perspective view of a laser machining apparatus in which a spot shape detection method of a laser beam according to the present invention is practiced.
Fig. 2 is a block diagram of the laser beam irradiation means provided in the laser machining apparatus shown in Fig. 1. Fig.
3 is a perspective view of a spot shape detecting mechanism constituting an apparatus for detecting a spot shape of a laser beam according to the present invention.
Fig. 4 is a perspective view explaining the constituent members of the spot shape detecting mechanism shown in Fig. 3 in an exploded manner. Fig.
Fig. 5 is an explanatory view showing the relationship between the micro prisms provided in the transparent substrate constituting the spot shape detecting mechanism shown in Fig. 3 and the light intensity detecting means.
Fig. 6 is a block diagram of control means provided in the laser machining apparatus shown in Fig. 1. Fig.
Fig. 7 is an explanatory diagram of a transparent substrate position giving step in a spot shape detecting method of a laser beam according to the present invention.
8 is an explanatory diagram of a light intensity detecting step in a spot shape detecting method of a laser beam according to the present invention.
9 is a diagram showing an example of a light intensity map created in the light intensity map creation step in the spot shape detection method of a laser beam according to the present invention.
10 is an explanatory diagram of a spot-shaped image forming step in the spot shape detecting method of the laser beam according to the present invention.

Best Mode for Carrying Out the Invention Hereinafter, preferred embodiments of a spot shape detecting method and a spot shape detecting device of a laser beam according to the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 is a perspective view of a laser processing machine for carrying out a spot shape detecting method of a laser beam according to the present invention. 1 includes a stationary base 2 and a chuck table mechanism 3 provided movably in the X axis direction indicated by an arrow X in the stationary base 2 to hold a workpiece, A laser beam irradiation unit support mechanism 4 provided on the stationary base 2 so as to be movable in the Y axis direction indicated by an arrow Y perpendicular to the X axis direction, And a laser beam irradiation unit 5 provided movably in a Z-axis direction indicated by an arrow Z perpendicular to the axial direction and the Y-axis direction.

The chuck table mechanism 3 includes a pair of guide rails 31 and 31 provided on the stationary base 2 in parallel along the X axis direction and a pair of guide rails 31 and 31 provided on the guide rails 31 and 31, A second sliding block 33 provided on the first sliding block 32 so as to be movable in the Y axis direction, and a second sliding block 33 And a chuck table 36 as a holding means for holding a workpiece. The chuck table 36 is supported by a cylindrical member 34, The chuck table 36 is provided with an adsorption chuck 361 made of a porous material. The measurement object is held by a suction means (not shown) on a holding surface which is an upper surface of the adsorption chuck 361. The chuck table 36 thus configured is rotated by a pulse motor (not shown) provided in the cylindrical member 34. The chuck table 36 is provided with a clamp 362 for fixing an annular frame for supporting the workpiece through the protective tape.

The first sliding block 32 is provided with a pair of to-be-guided grooves 321 and 321 which are engaged with the pair of guide rails 31 and 31 on the bottom surface thereof. A pair of guide rails 322, 322 are formed. The first sliding block 32 constructed as described above is configured such that the guided grooves 321 and 321 engage with the pair of guide rails 31 and 31 so as to be moved in the X axis direction along the pair of guide rails 31 and 31 . The chuck table mechanism 3 in the illustrated embodiment is configured to move the first sliding block 32 along the pair of guide rails 31 and 31 in the X- (37). The processing and conveying means 37 includes a male thread rod 371 provided parallel to the pair of guide rails 31 and 31 and a driving source such as a pulse motor 372 for rotationally driving the male screw rod 371 . One end of the male screw rod 371 is rotatably supported by a bearing block 373 fixed to the stationary base 2 and the other end of the male screw rod 371 is electrically connected to the output shaft of the pulse motor 372 have. The male screw rod 371 is threadedly engaged with a through-hole formed in a female screw block (not shown) provided on a central lower surface of the first sliding block 32. Accordingly, the first sliding block 32 is moved in the X-axis direction along the guide rails 31, 31 by rotating the male screw rod 371 by the forward and reverse rotations by the pulse motor 372. [

The laser processing machine in the illustrated embodiment is provided with X-axis direction position detection means 374 for detecting the movement position of the chuck table 36. [ The X-axis direction position detecting means 374 includes a linear scale 374a provided along the guide rail 31 and a linear scale 374b provided on the first sliding block 32 and together with the first sliding block 32, And a read head 374b that moves along the optical axis 374a. In the illustrated embodiment, the read head 374b of the X-axis direction position detecting means 374 sends a pulse signal of one pulse every 0.1 占 퐉 to the control means described later. The control means, which will be described later, detects the movement position of the chuck table 36 in the X-axis direction by counting the input pulse signal.

The second sliding block 33 has a pair of to-be-guided grooves 331 and 331 on its bottom surface for engaging with a pair of guide rails 322 and 322 provided on the upper surface of the first sliding block 32 And is configured to be movable in the Y-axis direction by fitting the to-be-guided grooves 331, 331 to the pair of guide rails 322, 322. The chuck table mechanism 3 according to the illustrated embodiment moves the second sliding block 33 along the pair of guide rails 322 and 322 provided in the first sliding block 32 in the Y axis direction And a first indexing feeding means 38 as an X-axis direction moving means. The first indexing conveying means 38 includes a male screw rod 381 provided parallel to the pair of guide rails 322 and 322 and a pulse motor 382 for rotationally driving the male screw rod 381 And a driving source. One end of the male screw rod 381 is rotatably supported by a bearing block 383 fixed to the upper surface of the first sliding block 32 and the other end of the male screw rod 381 is electrically connected to the output shaft of the pulse motor 382 It is connected. The male screw rod 381 is screwed to a through-hole formed in a female screw block (not shown) provided on a central lower surface of the second sliding block 33. Therefore, the second sliding block 33 is moved in the Y-axis direction along the guide rails 322 and 322 by driving the male screw rod 381 by the forward and reverse rotations by the pulse motor 382. [

The laser machining apparatus according to the illustrated embodiment is provided with Y-axis direction position detecting means 384 for detecting the Y-axis direction moving position of the second sliding block 33. [ Y-axis direction position detecting means 384 includes a linear scale 384a provided along the guide rail 322 and a linear scale 384a provided on the second sliding block 33 and together with the second sliding block 33, 384a. ≪ / RTI > In the illustrated embodiment, the read head 384b of the Y-axis direction position detecting means 384 sends a pulse signal of one pulse every 0.1 占 퐉 to a control means described later. The control means, which will be described later, detects the indexed transfer position of the chuck table 36 by counting the input pulse signal.

The laser beam irradiation unit support mechanism 4 includes a pair of guide rails 41 and 41 provided on the stationary base 2 in parallel along the Y axis direction and a pair of guide rails 41 and 41 on the guide rails 41 and 41, And a movable support base 42 provided movably in a direction. The movable support base 42 is composed of a movable support portion 421 movably provided on the guide rails 41 and 41 and a mounting portion 422 attached to the movable support portion 421. The mounting portion 422 is provided with a pair of guide rails 423 and 423 extending parallel to the Z-axis direction on one side surface thereof. The laser beam irradiation unit support mechanism 4 in the illustrated embodiment includes a second indexing feed means 43 for moving the movable support base 42 along the pair of guide rails 41, . The second indexing conveying means 43 includes a male screw rod 431 provided parallel to the pair of guide rails 41 and 41 and a pulse motor 432 for rotationally driving the male screw rod 431 And a driving source. One end of the male screw rod 431 is rotatably supported on a bearing block (not shown) fixed to the stationary base 2, and the other end is electrically connected to the output shaft of the pulse motor 432. The male screw rod 431 is screwed to a female screw hole formed in a female screw block (not shown) provided to protrude from a central lower surface of the movable support portion 421 constituting the movable support base 42. Therefore, the movable support base 42 is moved in the Y-axis direction along the guide rails 41, 41 by driving the male screw rod 431 in the forward and reverse rotations by the pulse motor 432.

The laser beam irradiation unit 5 in the illustrated embodiment includes a unit holder 51 and laser beam irradiating means 52 attached to the unit holder 51. [ The unit holder 51 is provided with a pair of to-be-guided grooves 511 and 511 slidably fitted on a pair of guide rails 423 and 423 provided in the mounting portion 422. The guided grooves 511 511 are fitted to the guide rails 423, 423 so as to be movable in the Z-axis direction.

The illustrated laser beam irradiating means 52 includes a cylindrical casing 521 fixed to the unit holder 51 and extending substantially horizontally. In the casing 521, as shown in Fig. 2, a laser beam emitting means 522 and an output adjusting means 523 are provided. The laser beam oscillating means 522 and the output adjusting means 523 are controlled by control means described later. The laser beam irradiating means 52 condenses the laser beam emitted from the laser beam oscillating means 522 and whose output is adjusted by the output adjusting means 523 and outputs the laser beam to the workpiece held on the chuck table 36 And a condenser 524 for radiating light. The condenser 524 is composed of a combination lens in which a plurality of convex lenses and a concave lens are combined, and is attached to the distal end portion of the casing 521.

1, the front end of the casing 521 constituting the laser beam irradiating means 52 is provided with a laser beam irradiation means for detecting a machining region to be laser machined by the laser beam irradiated from the condenser 524 And an image pickup means 55 is provided. The imaging means 55 includes an illumination means for illuminating a workpiece, an optical system for capturing an area illuminated by the illumination means, an imaging element (CCD) for imaging an image captured by the optical system, and the like , And sends the captured image data to the control means (not shown).

1, the laser beam irradiation unit 5 in the illustrated embodiment is configured to move the unit holder 51 in the Z-axis direction along the pair of guide rails 423 and 423 And a Z-axis direction moving means (53). The Z-axis direction moving means 53 is provided between the pair of guide rails 423 and 423 in the same manner as the above-mentioned processing and transfer means 37, the first indexing transfer means 38 and the second indexing transfer means 43, And a driving motor such as a pulse motor 532 for driving the male screw rod to rotate. A pulse motor 532 drives a male screw rod (not shown) The unit holder 51 and the laser beam irradiating means 52 are moved along the pair of guide rails 423 and 423 in the Z-axis direction.

The laser beam irradiation unit 5 in the illustrated embodiment is provided with Z-axis direction position detection means 54 for detecting the Z-axis direction position of the laser beam irradiation means 52. [ The Z-axis direction position detecting means 54 includes a linear scale 54a provided in parallel with the guide rails 423 and 423 and a linear scale 54a attached to the unit holder 51, And a read head 57b which moves along the scanning direction. In the illustrated embodiment, the read head 54b of the Z-axis direction position detecting means 54 sends a pulse signal of one pulse every 0.1 占 퐉 to the control means described later. The laser beam irradiation unit 5 is provided with an image pickup means 55 provided at the front end of the casing 521 of the laser beam irradiating means 52 for picking up an image of a machining region of a work to be described later. The image pickup means 55 sends the picked-up image signal to the control means described later.

3 shows a spot shape constituting a spot shape detecting device for detecting the spot shape of the laser beam emitted by the laser beam emitting means 522 of the laser beam irradiating means 52 and condensed by the condenser 524 A perspective view of the detection mechanism 6 is shown. The spot shape detecting mechanism 6 includes a base 61, a supporting means 62 provided on the base 61, a first supporting frame 63 supported on the supporting means 62, A second support frame 64 which is movably supported on the first support frame 63 in the X axis direction and a second support frame 64 which is supported on the second support frame 64 so as to be movable in the Y axis direction, (65), and light intensity detecting means (66).

In the illustrated embodiment, the base 61 is formed in a disc shape having substantially the same size as that of the chuck table 36. In the illustrated embodiment, as shown in Fig. 4, the support means 62 is composed of four support columns 621, and the four support pillars 621 are arranged in a rectangular shape. The first support frame 63 includes four side plates 631, 632, 633 and 634 having the same length and forming a square frame in the illustrated embodiment, And a pair of first guide rails 635 and 635 which are mounted on the lower surfaces of the side plates 631 and 632 parallel to the direction of the first guide rails 631 and 632 and project inward. As shown in Fig. 3, the first support frame 63 constructed as described above is mounted on the support means 62 composed of four support pillars 621.

As shown in Fig. 4, the second support frame 64 includes two side plates 641 and 642 having the same length and two side plates 643 and 644 having the same length, which form a rectangular frame, And a pair of second guide rails 645 and 645 mounted on the lower surfaces of the side plates 643 and 644 parallel to the Y axis direction on the lower surface of the side plate and projecting inward. The lengths of the two side plates 643 and 644 are formed to correspond to the dimensions between the inner surfaces of the side plates 631 and 632 of the first supporting frame 63. The length of the two side plates 641 and 642 is shorter than the length of the side plates 633 and 634 of the first support frame 63. [ An X-axis direction moving means 67 is mounted on the outer surface of one side plate 643 parallel to the Y-axis direction of the second supporting frame 64 constructed as described above. The X-axis direction moving means 67 is made up of a piezo element whose expansion width changes according to a voltage to be applied. In the illustrated embodiment, when a voltage of 1 V is applied, the X-axis direction moving means 67 is extended by 1 탆. 3, the second support frame 64 and the X-axis direction moving means 67 constructed as described above are arranged on the first guide rails 635 and 635 in the first support frame 63 do. The outer surface of the X-axis direction moving means 67 (the surface opposite to the surface mounted on the outer surface of the side plate 643) is mounted on the inner surface of the side plate 633 constituting the first support frame 63. Therefore, by applying a voltage to the X-axis direction moving means 67, the X-axis direction moving means 67 is extended along the first guide rails 635 and 635 corresponding to the applied voltage in the X-axis direction.

The transparent substrate 65 is formed of a quartz quartz substrate in the illustrated embodiment and is disposed between the inner surfaces of the side plates 643 and 644 parallel to the Y axis direction of the second support frame 64 As shown in Fig. A fine prism 651 having a size smaller than the size of the condensing spot of the laser beam irradiated from the condenser 524 is formed at the center of the surface of the transparent substrate 65. The fine prism 651 has a length A of 2 탆 and a width B of 2 탆 and an inclination angle C of 30 탆 as shown in Fig. A Y-axis direction moving means 68 is mounted on a side surface of the transparent substrate 65 structured as described above which is parallel to the width B direction of the fine prism 651. The Y-axis direction moving means 68 is composed of a piezo-electric element whose expansion width changes in accordance with a voltage applied in the same manner as the X-axis direction moving means 67. In the illustrated embodiment, a voltage of 1 V is applied And extend by 1 탆. 3 and 4, the transparent substrate 65 and the Y-axis direction moving means 68 constructed as described above are mounted on the second guide rails 645 and 645 in the second support frame 64 . The outer surface of the Y-axis direction moving means 68 (the surface opposite to the surface mounted on the side surface of the transparent substrate 65) is mounted on the inner surface of the side plate 642 constituting the second support frame 64 . Therefore, by applying a voltage to the Y-axis direction moving means 68, the transparent substrate 65 extends along the second guide rails 645 and 645 corresponding to the applied voltage in the Y-axis direction.

The light intensity detecting means 66 is provided at a position where the light refracted by the fine prism 651 on the base 61 can be captured. 5, the light intensity detecting means 66 includes an image-forming lens 661 positioned on the optical axis of the light refracted by the fine prism 651, and a light- And a photodetector 662 for capturing the light. The light intensity detecting means 66 thus configured sends a voltage signal corresponding to the light intensity of the light captured by the photodetector 662 to the control means described later.

The laser processing machine in the illustrated embodiment is provided with the control means 7 shown in Fig. The control means 7 is constituted by a computer and includes a central processing unit (CPU) 71 for performing calculation processing in accordance with a control program, a read only memory (ROM) 72 for storing a control program and the like, A random access memory (RAM) 73, a counter 74, an input interface 75, and an output interface 76. The random access memory (RAM) The X-axis direction position detection means 374, the Y-axis direction position detection means 384, the Z-axis direction position detection means 54, the image pickup means 55, and the image pickup means 55 are connected to the input interface 75 of the control means 7, A detection signal from the photodetector 662 or the like of the light intensity detecting means 66 is inputted. The pulse motor 372, the pulse motor 382, the pulse motor 432, the pulse motor 532, the laser beam emitting means 522, the output The X axis direction moving means 67, the Y axis direction moving means 68, the display means 70, and the like.

The laser processing machine in the illustrated embodiment is configured as described above, and its operation will be described below.

In order to detect the spot shape of the laser beam irradiated from the condenser 524 of the laser beam irradiating means 52 in the laser machining apparatus described above, as shown in Fig. 7, a transparent substrate (not shown) having the fine prism 651 The base 61 of the spot shape detecting mechanism 6 provided with the chuck table 65 is placed on the chuck table 36. At this time, the side plates 631 and 632 constituting the first support frame 63 are positioned so as to be parallel to the X-axis direction. Then, a suction device (not shown) is operated to hold the spot shape detecting mechanism 6 on the chuck table 36 by suction. Thus, the chuck table 36 holding the spot shape detecting mechanism 6 operates the processing means 37 as the X-axis direction moving means and the first indexing means 38 as the Y-axis direction moving means The center position of the chuck table 36 is positioned below the condenser 524 of the laser beam irradiating means 52 (on the optical axis (Z axis) of the laser beam condensed by the condenser 524) Substrate positioning process).

If the center position of the chuck table 36 is positioned immediately below the condenser 524 of the laser beam irradiating means 52, the laser beam irradiating means 52 is operated to move from the condenser 524 to the chuck table 36 And irradiates a laser beam onto a region where the fine prism 651 formed on the transparent substrate 65 constituting the held spot shape detecting mechanism 6 is located. The laser beam thus irradiated is set to an output (for example, 0.01 W) which can not process the transparent substrate 65 (laser beam irradiation step).

Next, the Z-axis direction moving means 53 is operated to move the condenser 524 of the laser beam irradiating means 52 in the Z-axis direction, and the condensing point of the laser beam condensed by the condenser 524 is moved to the chuck table (Upper surface) of the transparent substrate 65 constituting the spot shape detecting mechanism 6 held by the first detection position Z1 held by the first detection position Z1. The area where the fine prism 651 formed on the transparent substrate 65 constituting the spot shape detecting mechanism 6 held on the chuck table 36 is located is set to the light intensity detecting process starting position x1 , y1. 8 shows a case where the spot S of the laser beam irradiated from the light condenser 524 of the laser beam irradiating means 52 to the transparent substrate 65 and the spot S of the laser beam irradiated onto the transparent substrate 65 constituting the spot shape detecting mechanism 6 The formed fine prism 651 is shown in an exaggerated state. That is, the control means 7 operates the processing transfer means 37 as the X-axis direction moving means and the first indexing transfer means 38 as the Y-axis direction moving means to move the chuck table 36 in the X- Axis direction position detecting means 374 and the Y-axis direction position detecting means 384 in accordance with the detection signals from the X-axis direction position detecting means 374 and the Y- The fine prism 651 formed on the transparent substrate 65 is positioned at the coordinate value of (x1, y1), for example. The voltage applied to the X-axis direction moving means 67 mounted on the first support frame 63 of the spot shape detecting mechanism 6 is raised by 1 V and placed on the first support frame 63 The fine prism 651 formed on the transparent substrate 65 disposed on the second support frame 64 is moved to the coordinate value of (xn, y1). The movement of the fine prism 651 formed on the transparent substrate 65 is performed in a region where the spot S does not exist through the region where the spot S is located from the region where the spot S of the laser beam is not located . When the fine prism 651 formed on the moving transparent substrate 65 is not located in the spot S of the laser beam, the laser beam is not irradiated. Therefore, the photodetector 662 of the light intensity detecting means 66 The intensity of the light captured by the photodetector 662 is high because the laser beam is irradiated when the fine prism 651 is located in the spot S of the laser beam. When the fine prism 651 is located at the boundary of the spot S of the laser beam, the intensity of the light captured by the photodetector 662 is relatively low because the laser beam is partially irradiated. When the fine prism 651 formed on the transparent substrate 65 moves in this manner, the photodetector 662 of the light intensity detecting means 66 detects the light refracted by the fine prism 651 formed on the transparent substrate 65 And sends the light intensity signal to the control means 7. Based on the light intensity signal from the photodetector 662, the voltage value applied to the X-axis direction moving means 67 and the voltage value applied to the Y-axis direction moving means 68, the control means 7 controls the light- In the random access memory (RAM) 73, the light intensity corresponding to each coordinate value. Therefore, the control means for controlling the voltage value applied to the X-axis direction moving means 67 and the voltage value applied to the Y-axis direction moving means 68 is controlled by controlling the X value of the fine prism 651 formed on the transparent substrate 65 An X-axis direction position detection means for detecting an axial position, and a Y-axis direction position detection means for detecting a Y-axis direction position.

As described above, if scanning is performed from the (x1, y1) coordinate value to the (xn, y1) coordinate value, the voltage applied to the X-axis direction moving means 67 is released. As a result, the fine prism 651 formed on the transparent substrate 65 returns to the coordinate value of (x1, y1). Next, a voltage of 1 V is applied to the Y-axis direction moving means 68. As a result, the transparent substrate 65 is extended by 1 占 퐉 in the Y-axis direction along the second guide rails 645 and 645, and the fine prism 651 formed on the transparent substrate 65 has the coordinate value (x1, y2) Respectively. The voltage applied to the X-axis direction moving means 67 mounted on the first support frame 63 of the spot shape detecting mechanism 6 is raised by 1 V and placed on the first support frame 63 The fine prism 651 formed on the transparent substrate 65 disposed on the second support frame 64 is moved to the coordinate value of (xn, y2). When the fine prism 651 formed on the transparent substrate 65 moves in this manner, the photodetector 662 of the light intensity detecting means 66 detects the light refracted by the fine prism 651 formed on the transparent substrate 65 And sends the light intensity signal to the control means 7. Based on the light intensity signal from the photodetector 662, the voltage value applied to the X-axis direction moving means 67 and the voltage value applied to the Y-axis direction moving means 68, the control means 7 controls the light- In the random access memory (RAM) 73, the light intensity corresponding to each coordinate value. Next, the control means 7 scans from the (x1, y3) coordinate value to the (xn, y3) coordinate value and then scans from the sequential (x1, yn) coordinate value to the (xn, yn) coordinate value, And stores the light intensity at each (x, y) coordinate value detected by the intensity detecting means 66 in the random access memory (RAM)

If the light intensity detection process from the (x1, y1) coordinate value to the (xn, yn) coordinate value at the first detection position Z1 is performed as described above, the control means 7 controls the light intensity 9) based on the light intensity of the light refracted by the fine prism 651 formed on the transparent substrate 65 at each (x, y) coordinate value stored in the RAM 73 (RAM) 73 (a light intensity map forming step). The light intensity map is generated at each (x, y) coordinate value of the detection position Z1.

The control means 7 operates the Z-axis direction moving means 53 to drive the laser beam irradiation means (the Z-axis direction moving means) The condenser 524 of the condenser 52 is lowered by 1 占 퐉 in the Z-axis direction and the condenser 524 is positioned at the second detection position Z2. Then, at the second detection position Z2, the light intensity detection process and the light intensity map creation process are performed. Thereafter, the Z-axis direction moving means 53 is operated to lower the condenser 524 of the laser beam irradiating means 52 by 1 占 퐉 in the Z-axis direction, and the third detection position Z3, the fourth detection position Z4 , And the light intensity detecting process and the light intensity map forming process described above are performed at the fifth detection position (Z5) to the nth detection position (Zn), respectively.

Next, the control means 7 creates a spot-shaped image of the laser beam on the basis of the light intensity maps at the detection positions Z1 to Zn (spot-shaped image forming step). In this spot-shaped image forming process, since the laser beam is partially irradiated at the boundary of the spot S as described above, the intensity of the light captured by the photodetector 662 is comparatively low. Therefore, the outline of the spot S can be obtained based on the (x, y) coordinate values. 10 shows an outline of a spot S at each detection position Z1 to Z5 obtained by the spot-shaped image forming step, and this image is displayed on the display means 70 (display step). Therefore, the spot shape can be confirmed on the basis of the outline of the spot S displayed on the display means 70. In Fig. 10, the size (area) of the spot S at the third detection position Z3 is minimized. Therefore, the spot S in the third detection position Z3 becomes the condensing spot, the size (area) of the condensing spot can be obtained, and the focal distance of the condenser 524 can be obtained accurately. In the embodiment shown in Fig. 10, the image of the first detection position Z1 and the second detection position Z2 indicates a state where the condenser 524 is positioned at a position higher than the focal length, The image at the detection position Z4 and the image at the fifth detection position Z5 show a state in which the condenser 524 is positioned at a position lower than the focal distance. In the case where the spot shape created in the spot-shaped image forming process described above is different from the set shape, the optical axis of the group lens or the like is corrected by changing the condenser or affecting the processing quality.

Although the present invention has been described based on the embodiments shown in the drawings, the present invention is not limited to the embodiments, and various modifications are possible within the scope of the present invention. For example, in the illustrated embodiment, the moving means for moving the transparent substrate 65 having the fine prism 651 formed on the surface thereof in the X-axis direction and the X-axis direction are moved in the X-axis direction moving means 67 composed of piezo elements and Y As the moving means for moving the transparent substrate 65 formed on the surface of the fine prism 651 in the X-axis direction and the X-axis direction, the chuck table 36 may be moved in the X- And the first indexing feed means 38 as the Y-axis direction moving means can be used as the X-axis direction moving means and the X-axis direction moving means. In this case, the detection of the X-axis direction position and the Y-axis direction position of the fine prism 651 formed on the transparent substrate 65 is performed in the X-axis direction for detecting the position of the chuck table 36 in the X- Position detection means 374 and X-axis direction position detection means 374 can be used.

2: Stop base
3: chuck table mechanism
36: Chuck table
37:
374: X-axis direction position detection means
38: first indexing conveying means
384: Y-axis direction position detection means
4: Laser beam irradiation unit support mechanism
43: second indexing conveying means
5: laser beam irradiation unit
52: laser beam irradiation means
524: Concentrator
53: Z-axis direction moving means
54: Z-axis direction position detection means
6: Spot shape detection mechanism
61: Base
63: first support frame
64: second support frame
65: transparent substrate
651: fine prism
66: light intensity detecting means
67: X-axis direction moving means
68: Y-axis direction moving means
7: Control means
70: display means

Claims (4)

A spot shape detection method of a laser beam which is generated by a laser beam oscillation means and which detects a spot shape of a laser beam condensed by a condenser,
A transparent substrate on which fine prisms having a size smaller than the size of the condensing spot is formed on the surface is disposed on an optical axis (Z-axis) of a laser beam condensed by the condenser, in an X-axis direction orthogonal to the Z- Axis direction perpendicular to the Y-axis direction;
A laser beam irradiation step of condensing and irradiating a laser beam of an output which can not process the transparent substrate by the condenser, in a region where the fine prism formed on the transparent substrate is located;
A transparent prism is formed on the transparent substrate by moving the transparent substrate in the X-axis direction and the Y-axis direction relative to the light condenser while irradiating a laser beam on a region where the fine prisms formed on the transparent substrate are located, A light intensity detecting step of detecting light intensity by light intensity detecting means;
A light intensity map creating step of creating a light intensity map in x, y coordinate values of the fine prism detected in the light intensity detecting step
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The light intensity detecting step and the light intensity map forming step are performed at a plurality of detection positions in the Z axis direction of the condenser, A spot shape image forming step of creating a spot shape image; and a display step of displaying the spot shape image created by the spot shape image formation step on the display means. A spot shape detecting apparatus for a laser beam which detects a spot shape of a laser beam emitted by a laser beam generating means and condensed by a condenser,
A transparent substrate provided on an optical axis (Z-axis) of the laser beam condensed by the condenser and having a size smaller than the size of the focused spot on the surface; Axis direction moving means for moving the transparent substrate in the Y-axis direction orthogonal to the Z-axis direction and the X-axis direction; Z-axis direction moving means for moving the condenser in the Z-axis direction; Axis direction position detecting means for detecting a position of the fine prism formed on the transparent substrate in the Y-axis direction, and a position detecting means for detecting a position of the fine prism formed on the transparent substrate, Z-axis direction position detecting means for detecting a Z-axis direction position, light intensity detecting means for detecting light intensity of light refracted by the fine prism formed on the transparent substrate, A control means for obtaining a spot shape of the laser beam based on light detection means, detection signals from the X-axis direction position detection means, the Y-axis direction position detection means and the Z-axis direction position detection means, And display means for displaying the spot shape of the laser beam obtained by the above-
Wherein the control means controls the laser beam irradiation means to operate the laser beam emission means to irradiate a laser beam on a region where fine prisms formed on the transparent substrate are located, Axis direction moving means and the Y-axis direction moving means in a state in which a laser beam is irradiated to a region in which the fine prisms formed on the transparent substrate are located, to move the transparent substrate in the X-axis direction A light intensity detecting step of detecting the light intensity of the light refracted by the fine prism formed on the transparent substrate by the light intensity detecting means while moving the fine prism in the Y axis direction; , a light intensity map creation step of creating a light intensity map in the y coordinate value, Wherein the light intensity detecting step and the light intensity map forming step are performed at a plurality of detection positions in the axial direction and the spot shape image of the laser light beam is detected based on the plurality of light intensity maps generated in the light intensity map forming step And a display step of displaying the spot-shaped image created by the spot-shaped image forming step on the display means. The apparatus according to claim 2, wherein the transparent substrate is made of a quartz substrate, and the fine prisms are formed on a quartz substrate. The image display apparatus according to claim 2 or 3, wherein the light intensity detecting means includes: an image-forming lens positioned on an optical axis of light refracted by the fine prisms formed on the transparent substrate; And a photodetector for detecting the spot shape of the laser beam.

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