JPH0159076B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cutting device that suitably performs cutting using a laser beam.

Laser beams are focused and applied to cut various materials, but the problem in this case is molten matter adhering to the cutting surface. In particular, if a molten substance remains attached to a semiconductor crystal material, it will interfere with the manufacturing process after cutting, and will also affect the performance of the product. Measures to cut without molten material adhering to the cut surface include adjusting the processing scanning speed, or blowing away the molten material by jetting inert gas at high speed onto the cut surface. However, the results were not sufficient or the cut area became enlarged, resulting in inconveniences.

Figures 1 and 2 show what the inventor has done to solve the above drawbacks; 1 is a pulsed laser oscillator;
2 is a pulsed laser beam 3 emitted from this oscillator
A reflecting mirror 4 is a condenser lens for condensing and irradiating the pulsed laser beam 3 whose optical path has been changed by the reflecting mirror 2 onto the workpiece 5 . Reference numeral 6 denotes a moving table on which the workpiece 5 is placed and moved by the drive source 7 as shown by arrow A.
It is designed to move in the direction. Further, reference numeral 8 denotes a vibration drive source 8 for the reflecting mirror 2, which causes the reflecting mirror 2 to perform the repetitive motion shown by arrow B.

The cutting action of the above configuration will be explained next.

A workpiece 5 on which a moving table 6 is placed is irradiated with a pulsed laser beam 3 that has passed through a condenser lens 4 . At this time, the vibration of the reflecting mirror 2 must be set so that the pulsed laser beam does not come off the condensing lens 4, and the vibration must be set at a much higher speed than the moving speed of the workpiece 5. Then, on the processing scanning line 9, the pulsed laser beam 3 becomes a multiple beam 3a that oscillates over a portion x of the entire processing scanning length, and multiple repeated irradiations are repeated.

By the way, even if the pulsed laser beam 3 is performing a high-speed repetitive oscillation operation, the workpiece 5 is constantly moving, albeit at a low speed, so the pulsed laser beam 3 stops at the same location on the processing scanning line 9. Never. Therefore, the heat generated at the cutting part is dispersed, so that the temperature rise can be suppressed to a sufficiently low level. In addition, the material removed by each pulse of the pulsed laser beam 3 scatters in the direction of the incident beam, but since the irradiation position of each pulse changes from time to time as described above, from the front of the cutting to the rear. The cut surface 10 is sloped with its front side elevated.
A process of cutting while forming is performed. Therefore, as the machining progresses, the molten matter remaining inside the machining section is gradually reduced by being moved from the front of the cutting to the rear where the machining has already been completed, and therefore the molten matter is effectively removed from the cut surface. Ru. However, since the multiple beams are perpendicular to the processing surface of the workpiece 5, there is a difference in spot diameter between the front and back surfaces of the workpiece. Therefore, when the laser beam is focused so as to irradiate the smallest spot on the front surface, the cutting width becomes wider toward the back surface, resulting in a slanted cut surface. On the other hand, if the beam is focused to the smallest spot on the back side, it will be difficult to cut, and the cut surface will be wider on the front side and narrower towards the back side, which is the opposite of the above. I had a problem.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a laser cutting device capable of obtaining a cut surface having a narrow cutting width and an extremely small slope.

The present invention will be described below based on examples and drawings. Note that parts common to those in FIG. 1 will be described with the same reference numerals.

In FIG. 3, the moving table 6 is tilted so that the irradiation of the vibration center of the pulsed laser beam 3 hits the workpiece 5 obliquely, instead of at right angles as in the above embodiment, and the workpiece is scanned in the direction of arrow C. The cutting process is performed using the same method. In this embodiment, by adjusting not only the position of the condensing lens 4 with respect to the workpiece 5 but also the degree of inclination according to the thickness of the workpiece 5, the beam 3a can be used at a deep part on the front side of the workpiece and at a point where the focused diameter of the beam 3a is the smallest. The machined surface part on the rear side is irradiated, and the inclined cutting surface 1 connects the deep part and the machined surface part.
Processing is performed while forming 0. Therefore,
In this embodiment, regardless of the thickness of the workpiece, it is possible to process the workpiece from the front surface to the back surface with a focused beam of the minimum diameter, so that it is possible to cut the workpiece into a thin and straight cut surface.

Incidentally, in the above embodiments, the reflecting mirror 2 is of a galvanometer type, but is not limited to this.
It is also possible to use a method in which a polygon mirror is rotated to repeatedly scan a small range of distance at high speed. Further, even if the scanning shape of the processing part is not only a straight line but also a circular arc or any other arbitrary shape, there is no problem as long as the vibration beam side is matched.
Furthermore, since scanning is relative, the laser beam side may be scanned without moving the workpiece side.

As detailed above, when the pulsed laser beam is repeatedly operated in a small range on the processing scan, one end of the amplitude is focused on the surface of the workpiece during the amplitude of the small range, and the other end of the amplitude is focused on the surface of the workpiece. Since the machining is performed so that the chips are concentrated on the back surface of the workpiece, an oblique cut surface is formed so that the chips are gradually removed. When the workpiece 5 is made oblique as shown in FIG. 3, this oblique cut surface becomes a nearly horizontal plane, and the minimum spot extends over the entire thickness of the workpiece, which provides the above-mentioned effects. Not only was the molten material efficiently expelled to the outside, but the cutting surface was also burr-free and highly accurate.

[Brief explanation of drawings]

FIG. 1 is a block diagram for explaining the prior art of this invention, FIG. 2 is a plan view showing a processing part in FIG. 1, and FIG. 3 is a diagram for explaining one embodiment of this invention. . 1...Pulse laser oscillator, 2...Reflector, 3
a... Multiple beam, 4... Condensing lens, 5... Workpiece, 6... Moving table, 8... Vibration drive source, 10... Cutting surface.

Claims (1)

[Claims] 1 In a laser cutting device that scans a focused laser beam focused on a minute spot relative to a processing part according to the processing scanning shape of a workpiece, a part of the total length of the processing scan is applied to the laser beam. The method is characterized by comprising means for generating a vibrating beam with an amplitude range, and a table that holds the workpiece at an angle so that the vibration beam is obliquely incident on the processing surface of the workpiece. Laser cutting equipment.