JP2000071086A - Method and device for shape processing by laser light - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply deep engraving at a given depth to a processing area by moving a processing material in a direction perpendicular to a moving direction while a laser light is iteratively moved in a fixed direction at high velocity, and applying pattern processing and frame processing due to a sublimation action of the laser light. SOLUTION: When a laser light LA is oscillated along the longitudinal direction of a processing hole B at high velocity and moved in a fixed direction for forming one groove, an XY table 8 is oscillated in a horizontal direction for forming another groove. By repeating this, a large number of grooves are formed in an area of the processing hole B. Then, frame processing is applied along an outer surface of the shape of the processing hole B. The above- mentioned action is repeated until the pattern processing number, namely a processing layer number N is matched with the layer number of a given deep engraving distance. Then, semi-frame processing is applied, and a slight residual inclined taper of an end wall is further removed, so that the edge wall is processed to an approximately rectangular condition. The semi-frame processing is repeated plural times per layer, and processing is completed when a deep engraving distance becomes a given depth.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for processing a shape by a laser for performing a deep-cutting processing of a required depth on a material to be processed by a laser beam.

[0002]

2. Description of the Related Art Laser processing techniques for performing various processes such as cutting, drilling, and welding on metal parts by irradiating a laser beam have been developed, and the application range of the laser processing is wide. In the field of such laser processing technology, a method of melting and processing a material of a workpiece with high-energy laser light, such as the above-described cutting, drilling, and welding, is generally performed. For example, there is a so-called laser trimming process or a laser scribing process in which a high working energy far exceeding the melting temperature of various elements constituting the metal structure is applied to evaporate and vaporize a part of the metal structure.

Both the laser trimming and the laser scribing are one of the micromachining techniques. In the laser trimming, for example, a thick film resistor, a conductor, or the like is formed by printing on a printed circuit board, and each width is set to a predetermined width. It is used to cut and remove unnecessary parts such as resistors and conductors with laser light so that laser scribing is performed, for example, by grooving a block of a predetermined shape along a predetermined line, and Refers to a stage before the process of continuously crushing along the groove and dividing into small-sized blocks.

[0004] In such micromachining, the material is prevented from being heated and melted, and cutting or grooving is performed in a better evaporation state. In any case, the machining depth is several μm or more.
It is about several hundred μm. In many cases, a laser device used for such micro-machining is a Q-switch oscillation method that inserts a Q-switch element into an optical resonator optical path of a continuous excitation YAG laser and outputs about 1.5 times the continuous oscillation as a peak output. Is used.

[0005]

In both of the laser trimming and laser scribing processes described above, the material to be processed is irradiated with a laser beam of high peak power to a small depth of a metal partially or near the surface thereof. evaporation,
This is a method in which metal sublimation is instantaneously generated by vaporization and processing is performed.However, the effect of the laser beam reaches only a shallow state with a limited depth of focus at a small spot diameter position and a certain depth or more Cannot be processed.

However, some electronic parts and metal molds require deep carving of several millimeters in the thickness direction of the material. Such materials are often implemented by a machining apparatus. ing. Therefore, if you try to apply laser processing to the material you want to perform such deep engraving,
There are the following problems.

The first problem is that when deep engraving is performed by laser processing, the position of the spot diameter of the laser beam shifts depending on the depth, and the light is attenuated due to the non-irradiated portion of the metal which has been removed by sublimation. The inability to do deep carving. Secondly, since the laser beam condensed by the lens at the time of deep engraving has an irradiation angle, the cross section of the deeply engraved portion does not become perpendicular to the surface but becomes a tapered cross section.
When the deep engraving is performed with such a tapered cross section, a part to be fitted into the deep engraved portion cannot be fitted. Third, the processing speed is slow and the actual processing takes too much time.

In view of the above problems, the present invention makes it possible to perform deep engraving limited by laser light attenuation to a desired depth, and to substantially eliminate a tapered cross section by deep engraving to finish in practical use. It is an object of the present invention to provide a method and an apparatus for processing a shape by a laser beam which can be used as a laser beam.

[0009]

According to the present invention, as a means for solving the above-mentioned problems, a laser beam having a predetermined intensity or more is condensed and irradiated onto a material to be processed, and the laser beam is repeatedly moved in a fixed direction at a high speed. By moving the processing material in the direction perpendicular to the moving direction, the processing area is subjected to pattern processing by the sublimation of laser light, and at the same time, is irradiated with laser light along the outer periphery of the processing area to process the contour line processing. This processing is performed in this order or in the reverse order, and such a processing action is repeated while changing the condensing position of the laser light in the thickness direction of the processing material, so that the processing area is deeply carved to a desired depth. It was a processing method.

As an apparatus for performing this method, a laser oscillator and a laser beam having a predetermined intensity level or higher sent from the oscillator are reflected and moved in a fixed direction by a galvanometer mirror, and the laser beam is collected by a condenser lens. A processing table that movably supports the workpiece to be irradiated and a control unit that controls each of the above components. The control unit drives a galvanomirror to reflect and move the laser light, and orthogonally intersects the laser light. The laser beam is applied to the processing area by moving the processing table in the direction, and the above processing is repeated while changing the condensing position of the laser light in the thickness direction of the material to be processed to control the deep engraving processing to a desired depth. A shape processing device using laser light can be employed.

In the above-mentioned shape processing method and apparatus, the laser light is focused on the material to be processed as a laser light having a light intensity higher than a predetermined intensity level as a light source intensity capable of exerting a sublimation effect even on metals, ceramics, diamonds, etc. if condensed. At the light-condensing point, the irradiated portion of the material to be processed is instantaneously turned into plasma by the laser light condensed in an ultra-high temperature state, and is evaporated and vaporized to be sublimated and removed. The focal point is the focal position of the condenser lens, and when this focal position is set as the removal depth of the first layer and a laser beam is irradiated, the material up to that depth is sublimated and removed.

The laser beam is reciprocated within the processing area by reversing the galvanomirror at a high speed to perform a predetermined pattern processing, and then the laser light is moved along the outer periphery of the pattern to perform the contour processing. Done. The high speed is, for example, a speed of about 200 m / min for moving the laser beam. By this contour processing, the inclination taper of the cross section at the end is almost removed when the first layer is removed. Then, the above processing is repeated a number of times while changing the focal position of the laser beam with respect to the processing area in the thickness direction of the processing material, thereby performing deep engraving processing to a desired depth.

[0013]

Embodiments of the present invention will be described below. FIG. 1 shows an external perspective view of the laser processing apparatus according to the embodiment. As shown in the figure, this processing apparatus sends a laser beam emitted from a laser beam oscillator 1 to the outside as a pulse light of a Q switch oscillation by a Q switch 2 and swings the optical path by 90 ° by a fixed mirror 3 on the way to a galvano mirror 4. The laser beam is condensed by the condensing lens 6 and irradiates the material A to be processed.

5 is a motor for driving the galvanomirror 4,
7 is a light duct. The work material A is placed on the XY table 8, and the XY table 8 moves on the base plate 9 in any of the X-axis and the Y-axis, and can move up and down in the Z-axis direction.
A power supply / control unit 10 is provided below the oscillator 1.

In this embodiment, a YAG laser (wavelength: 1.06 μm) is used as the laser oscillator 1, and the laser light is output as continuous pulse output light of 500 W as pulse light having a peak value of 500 kW by Q-switch oscillation. You. This pulse light is deflected downward by the galvanometer mirror 4, but is oscillated in a fixed direction by rotating the galvanometer mirror 4 at a high speed by the motor 5, and reciprocates within a predetermined width range with respect to the material to be processed. Irradiated. The moving speed is a high speed of about 200 m / min in the illustrated example.

Although the XY table 8 is not shown,
A motor for driving the table in each of the X, Y, and Z axes is provided, and can rotate around the Z axis. The power supply / control unit 10 includes a power supply circuit for generating the pulse wave, and a control circuit for driving and controlling the laser oscillator 1 and each drive unit.

FIG. 2 is a conceptual diagram of processing by the laser processing apparatus having the above configuration. The laser beam LA is reciprocated by the galvanomirror 4 in the direction of the arrow shown in the figure to form a deeply machined hole B in the workpiece A. At this time, the laser light LA passes obliquely away from the optical axis center of the condenser lens 6 and can irradiate the end position of the processing hole B. The deep engraving refers to a process of removing a substance of the material A to be processed to a depth of at least a unit of mm or more.

The shape processing operation of the laser processing apparatus of this embodiment having the above-described configuration is performed as follows. Hereinafter, the shape processing operation will be described with reference to the flowchart of FIG. The shape processing according to this embodiment is performed by sublimating (evaporating and evaporating) the material of the irradiated portion of a hard-to-cut workpiece such as metal, ceramics, or diamond by laser light irradiation, and removing the material by at least mm units or more. The feature is that it is deeply carved to the processing depth of.

As shown in FIG. 3, Step S ₁ the first pattern processing is performed. This pattern processing is shown in FIG.
As shown in (1), for example, a large number of grooves are formed in a rectangular processing hole B in a direction parallel, oblique or at right angles to the longitudinal direction thereof to form a rough shape of the processing hole B. Needless to say, there are numerous machining shapes other than those illustrated.

As shown in FIG. 4, a laser beam LA is applied to a processing material A to form, for example, a rectangular processing hole B in the processing material A.
When the XY table 8 is moved at a high speed along the longitudinal direction and moved in a certain direction to form one groove, the XY table 8 is moved in the horizontal direction by the pitch of the groove width, and the laser beam LA is oscillated in the opposite direction. One groove is formed, and this is repeated to form a large number of grooves in the area of the processing hole B. The laser beam LA
The processing hole B is set so that the center line deflected right below by the galvanometer mirror 4 matches the center position of the processing hole B.

In the case of forming the one groove, as shown in FIG. 5, first, (a) when the laser beam LA is irradiated directly below the center line, the laser beam LA is focused on the focal position at that position. A spot-shaped processed hole is formed at a depth determined by the magnitude of the density. At this time, since the laser beam is generally focused to the smallest diameter at the position of the spot diameter, the position of the spot diameter becomes the deepest position of the processing hole depth, and the depth can be processed by one irradiation. Processing depth. This working depth is, for example, 15 μm in the apparatus of this embodiment.

(B) After forming a spot-shaped processing hole in the center of the processing hole B, the laser beam is moved and irradiated in a fixed direction, and at the end position of the processing hole, a slight oblique angle θ determined by the size of the processing hole B Illuminate the end with ₁ . For this reason, when drilling holes at the end, the laser beam is irradiated at a fixed focusing angle by the focusing lens, and part of the laser beam hits the end wall and the other side has been processed and there is no substance When the laser light comes into contact with the processing material, the contact surface of the laser light becomes non-uniform, irregularly reflected at the end wall, and the floating material of the processing material such as metal evaporated and vaporized by the sublimation action immediately before moving and irradiating the end. The laser light is absorbed by (ash).

Alternatively, the laser beam becomes slightly inclined at the end portion, so that the focal position (the position of the spot diameter) slightly increases and the degree of condensed light decreases. As shown in FIG. Although not shown, the end wall along the longitudinal direction of the processing hole B also has a slightly inclined shape due to the converging angle of the laser beam and the like.

The above processing is the pattern processing of the first layer, and in fact, deep engraving processing in units of mm is required, so that the above pattern processing must be repeated a plurality of times. However, if only this pattern processing is repeated several times,
As described above, a slight inclined taper is left on the end wall of the end of the processing hole each time, and the taper shape accumulates.
When it is necessary to embed a member close to a right angle, the machined hole B cannot be treated as a finishing process (unfinished process).

[0025] Therefore, in the shaping of the illustrated example subjected to contour machining along the outer shape of the machined hole B every time in step S ₂ to the patterned for each said layer. In this contour processing, as shown in FIG. 4 (b), the XY table 8 is moved in the direction perpendicular to the longitudinal direction at the end of the processing hole B in the longitudinal direction, and the width of the processing hole B is changed in the perpendicular direction. Laser irradiation is performed along the longitudinal direction at both ends in the direction.

In the illustrated example, such contour processing is performed by forming a contour on the outer periphery of each pattern every time deep engraving of each layer is performed by pattern processing. In this contour processing, the angle of the laser light acting on the end wall of the processing hole B is almost the same as that in the pattern processing. Scrape off little by little.

[0027] Therefore, when the contour line is inserted, the inclination taper of the end wall becomes a smaller angle, and when embedding a member which does not need to have high finishing accuracy of the machined hole, it is actually treated as sufficiently finished. Can be. FIG.
(B) shows a plurality of contour lines, which show some of the processing lines in each layer because a slightly inclined tapered wall remains on the outer periphery even if deep engraving is performed for each layer in the pattern processing. I have. The outermost side of the contour is the finish dimension line.

When a large number of contour lines are inserted and deep engraving is performed as described above, the inclined taper is gradually removed as described above. The cross-sectional state is shown in FIG. The broken taper indicated by the dashed line indicates the finish when the contour is not inserted, and the slope taper indicated by the solid line indicates the finished state when the contour is inserted.

[0029] When the contour line machining of the first layer after the machining to put an outline is completed as described above, is raised by a distance corresponding to the XY table 8 to the machining depth by patterning the first layer in S ₃ . Then, by measuring the increase in distance in the counter in the control circuit determines whether the sum of the elevating distance matches the required depth engraving distance should be finished machined as compared with S _4.

When the pattern processing is the first layer, the above operation is repeated because the pattern does not coincide with the deep engraving distance. At this time,
The number a is working layer number N of patterned to N while 1 incremented at S ₅ is equal to the number of layers of required depth carving distance repeat the above action.

[0031] When S ₄ above processing layer number N is equal to the number of layers of required depth engraving distance, then subjected to semi-contour machining S ₆ following steps. This half contour line processing is performed in order to further remove the slight inclined taper of the end wall still remaining in the processing processing up to the above-described contour line processing, and to process the end wall into a state close to a right angle. It is.

[0032] The XY table 8 in step S ₆ X, Y
The center line of the laser beam is shifted by a predetermined distance from the center line of the processing hole B as shown in FIG.
While subjected to similar contour machining the contour line processing at S ₂ described above in S ₇ in this state, one side of the machined hole B since the center line of the case where the laser beam is shifted, that is, the direction of shifting the center line opposite Only the side wall can be machined.

Therefore, the processing in this case is called semi-contour processing. In this half contour processing, the angle (θ ₂ ) irradiated to the end wall is larger than the irradiation angle (θ ₁ ) in the previous contour processing, so that the sublimation effect by the laser light is more likely to enter the end wall. The slight taper remaining on the end wall is thereby cut away so that the end wall is substantially perpendicular.

[0034] the semi While contour machining is repeated a plurality of times for each layer like the outline processing of S _2, each distance corresponding to the depth carving distance scraped for each layer XY table 8
The raised at S _8, it is determined whether the processing end by the distance S _9, increments the S ₁₀ each number in M by one. The processing ends when the deep engraving distance reaches a predetermined depth. In the above-mentioned processing, for example, it takes about 20 minutes to deeply carve a hole of 5 cm square to a depth of about 5 mm.

In the above example, contour processing is performed after pattern processing for each layer, and this processing is repeated a plurality of times. However, pattern processing is performed for all layers first, and then contour processing is performed for all layers. It may be performed. Although the pattern processing and the contour processing are performed first, the processing may be performed in the reverse order.

[0036]

As described above in detail, in the shape processing method and apparatus according to the present invention, pattern processing and contour processing by sublimation of a laser beam moving at a high speed are repeatedly performed on a processing area a plurality of times. Because the deep carving of the desired depth is performed, it becomes possible to perform deep carving by laser processing of difficult-to-cut materials, which has been impossible in the past, and the inclined taper part generated in the end cross section by the deep carving is almost A shape processing method and apparatus which can be removed and practically handled as finish processing can be obtained.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a laser processing apparatus.

FIG. 2 is a schematic diagram of main components.

FIG. 3 is a flowchart of a shape processing operation.

FIG. 4 is an explanatory view of the function of shape processing.

FIG. 5 is an explanatory view of an operation of the shape processing.

FIG. 6 is a diagram illustrating types of pattern processing.

FIG. 7 is an explanatory diagram of half contour processing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser oscillator 2 Q switch 3 Fixed mirror 4 Galvano mirror 5 Motor 6 Condensing lens 8 XY table 9 Base plate 10 Power supply / control part

Claims (3)

[Claims] 1. A processing area by converging and irradiating a laser beam having a predetermined intensity or more on a material to be processed and moving the processing material in a direction orthogonal to the moving direction while repeatedly moving the laser beam in a fixed direction at a high speed. The pattern processing by laser light sublimation is performed on the surface, and the contour processing for processing the contour by irradiating the laser light along the outer periphery of the processing area is performed in this order or in the reverse order, and such a processing action is performed. A shape processing method using laser light, wherein a processing area is repeatedly carved to a desired depth while changing the focal position of the laser light in the thickness direction of the processing material. 2. After the deep engraving, the laser beam irradiation center position is moved by an appropriate distance to perform a semi-contour processing for irradiating the laser beam along the outer periphery of the processing area. 2. The method according to claim 1, wherein the light condensing position is repeated while changing the light condensing position in the thickness direction of the processing material. 3. A laser oscillator, and a laser beam having a predetermined intensity level or higher sent from the oscillator is reflected and moved in a fixed direction by a galvanomirror, and the laser beam is condensed by a condenser lens and irradiated. A machining table for movably supporting the workpiece and a control unit for controlling the above-mentioned components; the control unit drives the galvanomirror to reflect and move the laser beam and to move the machining table in a direction orthogonal to the laser beam; The laser beam is applied to the processing area, and the above processing is repeated while changing the laser light focusing position in the thickness direction of the material to be processed, thereby controlling the deep engraving processing to a desired depth. Characteristic shape processing device using laser light.