JPH1133765A - Laser processing equipment - Google Patents

Abstract

(57) [Problem] To provide a laser processing apparatus in which the processing capability of laser processing is improved by increasing the effective repetition frequency using a plurality of laser light sources. A laser processing apparatus (20) irradiates a workpiece (9) with laser beams (1a, 3a), and processes the workpiece (9). A plurality of processing lasers irradiate the laser beams (1a, 3a) on the same optical axis. The laser light source 1 includes a light source 1 and a control unit 15 that instructs the processing laser light sources 1 and 3 to transmit the laser beams 1a and 3a in a predetermined order. Before the control unit 15 issues an instruction to transmit the laser beams 1a, 3a to the processing laser light sources 1, 3, a moving means for moving the processing location on the workpiece 9 on the optical axis is provided. In addition.

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 having improved laser processing capability.

[0002]

2. Description of the Related Art A laser processing apparatus irradiates a laser beam emitted from a laser light source onto a workpiece, particularly a pattern on a semiconductor substrate, through an irradiation optical system to perform a processing (cutting) process. 2. Description of the Related Art A conventional laser processing apparatus uses one equipped with one laser light source for processing a workpiece.

[0003]

The main factors that determine the processing capability of a laser processing apparatus are the following two.
The first factor is how to quickly position the processing laser beam and the processing point of the workpiece. Second
The second factor is the repetition frequency of the processing laser. That is, in general, in the case of a pulse laser, if the laser is transmitted at an interval shorter than a certain frequency, the laser energy per operation is reduced, and stable processing cannot be performed. For this reason, when processing is performed continuously, it is necessary to provide an interval from a certain processing to the next processing for a certain time or more. Therefore, even if an attempt is made to increase the repetition frequency of the processing laser in order to increase the processing capability of the laser processing apparatus, there is a certain limit due to the need to perform stable processing.

[0004] From the above, even if the positioning control speed of the workpiece, which is the first element, is increased in order to increase the processing capacity of the laser processing apparatus, the processing capacity is increased because of the second element. There is a limit to the improvement. Also, the second
To increase the repetition frequency of the processing laser, which is the second element, it is necessary to improve the laser light source itself, but there is a limit in practice.

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 increase the effective repetition frequency by using a plurality of laser light sources to increase the processing capability of laser processing. An object of the present invention is to provide an improved laser processing apparatus.

[0006]

Means for Solving the Problems 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 performing processing on the workpiece. It is characterized by comprising: a plurality of processing laser light sources that irradiate laser light; and a control unit that instructs the processing laser light source to transmit the laser light in a predetermined order. Further, it is preferable that the apparatus further includes a moving means for moving a processing place on the workpiece on the optical axis before the control section issues an instruction to transmit the laser light to the processing laser light source.

In the above-mentioned laser processing apparatus, a plurality of processing laser light sources are mounted, and instructions for transmitting laser light are issued from the control unit to the processing laser light sources in a predetermined order. The workpiece can be irradiated through the shaft. Accordingly, the workpiece can be processed at a processing interval equal to or more than the repetition frequency of the processing laser, that is, at a processing interval substantially equal to the number of laser light sources equipped with the laser repetition frequency. In other words, even if a laser having a low repetition frequency is used, it can be considered that the repetition frequency is actually increased by using a plurality of lasers. Therefore, the processing capability of the laser processing device can be significantly improved.

[0008]

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 20 has first and second processing laser light sources 1 and 3. The first processing laser light source 1 emits a first processing laser beam 1a under the control of the control unit 15 described later. The laser beam 1a passes through the first light amount variable section 2, the processing laser beam half mirror 5, the variable aperture 6, the dichroic mirror 7, and the objective lens 8 in this order, and the workpiece (semiconductor) fixed on the stage 10 (Substrate / wafer) 9. Thereby, the workpiece 9 is processed.

The second processing laser light source 3 is
The second processing laser beam 3a is emitted in accordance with the control of Step 5.
The laser light 3a passes through the second light amount variable section 4 and is processed by the processing laser light half mirror 5 into the first processing laser light 1.
The light is reflected on the same optical axis as that of the first processing laser beam 1a, and then passes through the same path as the first processing laser beam 1a. That is, the second processing laser beam 3a reflected by the half mirror 5 passes through the variable aperture 6, the dichroic mirror 7, and the objective lens 8 in this order, and the workpiece (semiconductor substrate / wafer) fixed on the stage 10 9 is irradiated. Thereby, the workpiece 9 is processed. The dichroic mirror 7 reflects most of the incident first and second laser beams 1a and 3a.

The control unit 15 controls the first and second processing laser light sources 1 and 3, the first and second light amount variable units 2 and 4, the variable aperture 6, and the stage 10. The storage unit 15a is provided inside the control unit 15. In the storage unit 15a, a processing position, an appropriate laser power, a beam size, and the like are stored for each type of the workpiece 9.

Further, the control unit 15 instructs the power of the first processing laser 1 to the first light quantity variable unit 2 before processing based on the information in the storage unit 15a, Laser 3
Is instructed to the second light quantity varying unit 4.

The control section 15 controls a moving means (not shown) for moving the stage 10 based on the information in the storage section 15a. That is, when performing the laser processing, the work 9
Is moved to a predetermined position to instruct the processing location on the workpiece 9 to be located on the optical axis of the laser, and to reach one of the first or second processing lasers 1 and 3 as soon as the processing location is reached. Put out. Thereafter, the control unit 15 instructs the next processing location on the workpiece 9 to be located on the optical axis of the laser, and as soon as the processing location is reached, the first or second processing location.
Of one of the processing lasers 1 and 3 is transmitted.

Thus, the first and second processing lasers 1, 3
The processing is performed regardless of which instruction is issued, but the instruction is issued alternately. Thereby, processing is performed continuously using the two processing lasers.

The moving means makes it possible to move the stage 10 in the vertical or horizontal direction with respect to the laser beam and to rotate on a horizontal plane about a predetermined drive shaft.

The laser processing apparatus 20 is used to
Light source (illumination light source) 11 for observing the processing state of
have. The illumination light 11a emitted from the illumination light source 11 passes through the illumination light half mirror 12, the dichroic mirror 7, and the objective lens 8 in order, and is irradiated onto the workpiece 9. The reflected light from the workpiece 9 is returned to the objective lens 8, the dichroic mirror 7, the illumination light half mirror 1 again.
The light is sequentially incident on the CCD camera 13 after passing through 2.

The illumination light source 11 has a built-in 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 13 converts the reflected light from the workpiece 9 into an image signal and outputs it to an image processing unit (not shown). The image processing unit outputs an image signal (video signal) input from the CCD camera 13 to the TV monitor 14 and performs predetermined processing on the image signal. TV monitor 1
Reference numeral 2 displays and outputs the image signal output from the image processing unit. That is, it is displayed on the TV monitor 14 as a video signal.

According to the above embodiment, the first and second processing laser light sources 1 and 3 are mounted on the laser processing apparatus 20,
The control unit 15 alternately issues instructions for transmitting laser light to the first and second processing laser light sources 1 and 3, and both laser lights 1 a and 3 a passing through the processing laser light half mirror 5 have the same optical axis. The workpiece 9 is radiated through the workpiece. For this reason, the workpiece 9 can be processed by irradiating the workpiece 9 with laser light at the same interval as when the repetition frequency of the laser is doubled. Therefore, the processing capability of the laser processing device 20 can be improved.

In the above embodiment, two processing lasers are mounted on the laser processing apparatus 20, but three or more processing lasers can be mounted on the laser processing apparatus 20. Thereby, a repetition frequency proportional to the number of mounted processing lasers can be obtained.

[0021]

As described above, according to the present invention, a plurality of processing laser light sources are mounted, and a control unit issues a laser light transmission instruction to the processing laser light sources in a predetermined order. Is irradiated on the workpiece through the same optical axis. Therefore, the repetition frequency can be effectively increased by using a plurality of laser light sources, and the processing capability of laser processing can be improved.

[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.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st processing laser light source 1a ... 1st processing laser light 2 ... 1st light amount variable part 3 ... 2nd processing laser light source 3a ... 2nd processing laser light 4 ... 2nd light amount variable part 5 ... Half mirror for processing laser light 6 ... Variable aperture 7 ... Dichroic mirror 8 ... Objective lens 9 ... Workpiece 10 ... Stage 11 ... Observation light source 11a ... Illumination light 12 ... Half mirror for illumination light 13 ... CCD camera 14 ... TV monitor 15 ... Control unit 15a ... Storage unit 20 ... Laser processing device

Claims (2)

[Claims] 1. A laser processing apparatus for processing a workpiece by irradiating the workpiece with laser light; a plurality of processing laser light sources for irradiating laser light on the same optical axis; And a control unit for issuing an instruction to transmit the laser light in the order of. 2. The apparatus according to claim 1, further comprising moving means for moving a processing location on the workpiece on an optical axis before the control section issues an instruction to transmit the laser light to the processing laser light source. The laser processing apparatus according to claim 1, wherein