JPH1119788A - Laser beam machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser beam machine capable of precisely machining a work with a beam shape suitable to the shape of the work. SOLUTION: The laser beam machine 30, by which a work 7 is machined by being irradiated with a laser beam 1a, is equipped with a CCD camera 12 for picking up the image of the work 7, an image processor 15 for recognizing the planar shape of the work 7 from the image data, a data processor 14 for selecting from plural beam shapes one that is suitable to the work 7, and a variable aperture 3 for switching the beam shape to this selected one.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus, and more particularly to a laser processing apparatus capable of processing a workpiece accurately by using a beam shape suitable for the shape of the workpiece.

[0002]

2. Description of the Related Art A laser processing apparatus irradiates a workpiece with a laser beam emitted from a laser light source via an irradiation optical system to perform a processing process.

Conventionally, this type of device is often used to irradiate a fuse provided on a circuit pattern of a semiconductor device with a laser beam to cut a wiring. The fuse is provided in the circuit by a pattern of a material and a shape that can be easily cut during laser processing.

[0004] In the conventional laser processing apparatus, the workpiece on the stage is processed with one type of beam shape (beam planar shape) regardless of the shape of the workpiece (fuse planar shape).

[0005]

As described above, in the conventional laser processing apparatus, since the workpiece is processed with one type of beam shape, when the beam shape does not match the shape of the workpiece. In some cases, an unprocessed portion may be present in the processed workpiece, or a portion other than the intended portion (a portion other than the portion to be processed) may be processed.

Next, the problem in the case of processing a workpiece with one type of beam shape will be specifically described. FIG. 4 (a)
FIG. 4B is a plan view showing a fuse on a semiconductor substrate and a beam shape irradiated on the fuse by a conventional laser processing apparatus. FIG. 4B is a plan view showing a fuse on the semiconductor substrate and a conventional laser processing apparatus on the fuse. FIG. 7 is a plan view showing another beam shape irradiated by the laser beam.

[0007] As shown in FIG. 4 (a), a small beam shape 17
, The fuse 16 cannot be completely processed. That is, if the beam shape 17 is smaller than the fuse 16, the cut width of the fuse 16 cannot be sufficiently secured.
It is not possible to ensure sufficient electrical insulation resistance in the fuse 16 after cutting.

On the other hand, as shown in FIG. 4B, if a large beam shape 20 is used for the fuse 18 as one type of beam shape, a part of the adjacent fuse 19 will be processed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a laser processing apparatus capable of accurately processing a workpiece by using a beam shape suitable for the shape of the workpiece. Is to do.

[0010]

In order to solve the above problems, a laser processing apparatus according to the present invention is a laser processing apparatus for irradiating a workpiece with a laser beam and processing the workpiece. Recognition means for recognizing the shape of the workpiece from the obtained image, selection means for selecting a laser beam shape suitable for processing the workpiece from the shape recognized by the recognition means, and selection means selected by the selection means. Shaping means for shaping the laser beam into a shape. The selecting means selects a vertically long beam shape when the shape recognized by the recognition means is vertically long, and selects a horizontally long beam shape when the shape recognized by the recognition means is horizontally long. It is preferred that

In this laser processing apparatus, the shape of the workpiece is image-recognized by the recognition means, and the shape of the laser beam suitable for processing the workpiece is selected from the recognized shape by the selection means. A laser beam is formed into a shape by a forming unit. Therefore, it is possible to automatically select a beam shape suitable for processing the workpiece and irradiate the beam to the workpiece. Therefore, the workpiece can be accurately processed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a laser processing apparatus according to an embodiment of the present invention.

The laser processing apparatus 30 has a control unit 9 for controlling each of the processing laser light source 1, the light quantity variable unit 2, the variable aperture 3, and the stage 8. The processing laser light source 1 emits the processing laser light 1a under the control of the control unit 9. The processing laser light 1a emitted from the processing laser light source 1 passes through the variable light amount unit 2, the variable aperture 3 for changing the beam size and the beam shape, the dichroic mirror 4, the half mirror 4a, and the objective lens 6 in this order, and passes on the stage 8. The work 7 is fixed to the workpiece 7. Thereby, the workpiece 7 is processed. still,
The dichroic mirror 4 reflects most of the incident laser light 1a.

The light amount variable section 2 is provided with a polarizing plate, and the amount of laser light is adjusted by rotating the polarizing plate with respect to the polarization plane of the laser light. In addition, the variable aperture 3 receives the processing laser light 1 according to an instruction from the control unit 9.
It has a function of changing the size of the beam a and switching the beam shape to a beam shape suitable for the fuse shape. In other words, the variable aperture 3 is configured to select and switch an optimal shape or an appropriate shape from a plurality of beam shapes that can be switched by changing the beam size in accordance with an instruction from the control unit 9.

The stage 8 is provided with moving means (not shown) which is driven and controlled by the control unit 9. This moving means enables the stage 8 to move in the vertical or horizontal direction with respect to the laser beam, and also allows the stage 8 to rotate on a horizontal plane about a predetermined drive shaft. Therefore, the movement and rotation of the workpiece 7 are performed by moving the stage 8. Further, the stage 8 is provided with position detecting means (not shown) for detecting the position movement of the stage 8, and this position detecting means is controlled by the control unit 9.

An energy meter 5 is provided at an end of the stage 8.
Is placed. The irradiation energy is set as follows. First, the energy is monitored by the energy meter 5 on the stage 8, and the control unit 9 adjusts the light amount variable unit 2 so as to have a predetermined energy, and sets the irradiation energy. In addition, the energy during processing is measured by the light amount sensor 5a
And the controller 9 measures energy stability and the like.

Further, the laser processing device 30 is used to
Has an observation light source 10 for observing the processing state of. The observation light 10a emitted from the observation light source 10 passes through the reflection mirror 11, the dichroic mirror 4, the half mirror 4a, and the objective lens 6, and is irradiated onto the workpiece 7 in order. The reflected light from the workpiece 7 is again reflected by the objective lens 6,
The light passes through the half mirror 4a, the dichroic mirror 4, and the reflection mirror 11 in order, and passes through a CCD (Charge Coupled Device).
) Light is incident on the camera 12.

The observation light source 10 incorporates a halogen lamp and an optical filter that transmits only a predetermined wavelength band.
Light emitted from the halogen lamp is emitted through an optical filter.

The CCD camera 12 converts light reflected from the workpiece 7 into an image signal. The converted image data (image signal) is sent to the image processing unit 15. The image processing unit 15 recognizes an image pattern based on the image data input from the CCD camera 12, and the result is transmitted to the data processing unit 14. Further, the image processing unit 15 outputs the image data to the TV monitor 13. The TV monitor 13 displays and outputs an image signal output from the image processing unit 15. The data processing unit 14
Has a fuse table file. In this fuse table file, the position of the fuse as the workpiece 7 is registered in advance as fuse coordinates.

Next, the procedure for selecting and processing the beam shape in the laser processing apparatus 30 will be described.

FIG. 2 is a flowchart showing the procedure of beam shape selection and processing in the laser processing apparatus. FIG. 3A is a plan view showing a vertically long fuse 21 on a semiconductor substrate and a beam shape 22 irradiated thereon by the laser processing apparatus shown in FIG. 1, and FIG. FIG. 2 is a plan view showing a horizontally long fuse 23 and a beam shape 24 irradiated thereon by the laser processing apparatus shown in FIG. 1.

First, as shown in FIG. 2, the fuse coordinates in the fuse table file are read. That is, data (fuse coordinates registered in advance) in the fuse table file is sent from the data processing unit 14 to the control unit 9.

Thereafter, the stage is moved to the fuse coordinates, the image is captured, and the shape of the image is recognized. That is, the control unit 9 drives and controls the moving unit based on the fuse coordinates, so that the stage 8 is moved before the fuse processing so that the fuse to be processed is located on the optical axis of the laser. Then, the image showing the fuse is CC
The plane shape of the fuse is recognized by capturing the image data with the D camera 12 and processing the image data in the image processing unit 15.

Next, a beam shape corresponding to the fuse shape is selected, and the information is written in a fuse table file. That is, when the planar shape of the fuse recognized by the image processing unit 15 is a vertically long fuse 21 as shown in FIG. 3A, a vertically long rectangular beam shape 22 suitable for the direction of the fuse 21 is selected. The information is recorded in the fuse table file. If the fuse has a horizontally elongated fuse 23 as shown in FIG. 3B, the horizontally elongated rectangular beam shape 24 suitable for the direction of the fuse 23 is selected. The information is recorded in the fuse table file.

By repeating the above procedure,
A beam shape for each fuse on the semiconductor substrate is selected, and the information is recorded in a fuse table file.

Thereafter, fuse processing is started. A fuse data file containing the fuses to be machined,
The fuse coordinates and the beam shape are determined from the fuse table file in which the fuse coordinates and the beam shape are written.

Next, the variable aperture 3 is switched by the control unit 9 so that the laser beam 1a has the determined beam shape. The stage 8 is moved so that the fuse to be processed is located at the determined fuse coordinates. Then, the laser is irradiated to process the fuse.

According to the above embodiment, the stage 8 is moved by the moving means so that the fuse is positioned on the optical axis of the laser, the image of the fuse is captured by the CCD camera 12, and the image processing unit 15 is obtained from the image data. Recognizes the planar shape of the fuse, and determines a beam shape suitable for the fuse shape from the plurality of beam shapes by the data processing unit 1.
Select with 4. Then, the beam shape is changed by an aperture 3
Then, the shape is changed to a shape suitable for the shape of the fuse as the workpiece, and the fuse is processed by the laser beam. Therefore, the unprocessed portion does not occur in the processed fuse or a portion other than the intended portion is not processed, so that the fuse can be accurately processed.

Further, since the beam shape is determined by recognizing the shape of the workpiece 7 by image recognition, the number of operator operations can be reduced.

[0030]

As described above, according to the present invention, it is possible to provide a laser processing apparatus capable of accurately processing a workpiece with a beam shape suitable for the shape of the workpiece.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a laser processing apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a procedure of beam shape selection and processing in the laser processing apparatus.

3A is a plan view showing a vertically long fuse on a semiconductor substrate and a beam shape irradiated thereon by the laser processing apparatus shown in FIG. 1, and FIG. 3B is a plan view showing the semiconductor substrate; FIG. 2 is a plan view showing an upper oblong fuse and a beam shape irradiated thereon by the laser processing apparatus shown in FIG. 1.

FIG. 4A is a plan view showing a fuse on a semiconductor substrate and a beam shape irradiated thereon by a conventional laser processing apparatus, and FIG. 4B is a view showing a fuse on the semiconductor substrate. FIG. 11 is a plan view showing another beam shape irradiated thereon by a conventional laser processing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Processing laser light source 1a ... Processing laser light 2 ... Light amount variable part 3 ... Variable aperture 4 ... Dichroic mirror 4a ... Half mirror 5 ... Energy meter 5a ... Light amount sensor 6 ... Objective lens 7 ... Workpiece 8 ... Stage 9 ... Control Unit 10: Observation light source 11: Reflecting mirror 12: CCD camera 13: TV monitor 14: Data processing unit 15: Image processing unit 16: Fuse 17: Beam shape 18: Fuse 19 ... Fuse 20 ... Beam shape 21: Vertical fuse 22 ... Beam shape 23 ... Horizontal fuse 24 ... Beam shape 30 ... Laser processing equipment

Claims (2)

[Claims] 1. A laser processing apparatus for processing a workpiece by irradiating a laser beam to the workpiece; a recognizing means for recognizing a shape of the workpiece from an image reflecting the workpiece; A laser comprising: a selecting unit that selects a shape of a laser beam suitable for processing a workpiece from a recognized shape; and a forming unit that shapes the laser beam into a shape selected by the selecting unit. Processing equipment. 2. The method according to claim 1, wherein the selecting means selects a vertically long beam shape when the shape recognized by the recognition means is vertically long, and selects a horizontally long beam shape when the shape recognized by the recognition means is horizontally long. 2. The laser processing apparatus according to claim 1, wherein the laser processing apparatus is selected.