JP2007185694A - Laser jet machining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser jet machining device, which remarkably increases the pressure of a liquid jet so that machining can be performed by only the liquid jet and the supporting effect of the laser beam is further enhanced. <P>SOLUTION: A nozzle 50 has a cylindrical portion and a conical portion having smaller diameter toward its front end, at which an injection port 54 is formed. A laser beam introducing tube 60, which introduces a laser beam L into the nozzle 50, and a liquid jet introducing tube 70, which introduces a liquid jet containing abrasive grains into the nozzle 50, are removably connected to the nozzle 50. The pressure of the liquid jet is remarkably increased by such a structure that the strength of the nozzle 50 can be increased. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laser-jet processing apparatus that applies a laser beam and a high-pressure liquid (liquid jet) containing abrasive grains to a workpiece at the same time to perform required processing such as cutting.

  A combined processing machine that performs laser processing and liquid jet processing at the same time by irradiating a laser beam coaxially with a liquid jet obtained by injecting a liquid such as water into a high-pressure beam and injecting the same into a workpiece is known. (For example, Patent Documents 1 and 2). Such a processing apparatus is generated by processing only the laser beam by removing the processing waste generated by the heat of the laser beam with the pressure of the liquid jet to prevent reattachment or cooling the processing point with the liquid jet. The problem is solved by applying a liquid jet. As an object to be processed, a relatively brittle material such as a semiconductor wafer or a substrate made of a thin resin plate is effective.

JP 2001-321977 A JP 2001-287071 A

  The processing apparatus described in Patent Document 1 emits a liquid jet introduced into a conical cylindrical nozzle to increase the pressure of a water flow and a laser beam passed through a condenser lens fixed to the nozzle from an opening at the tip of the nozzle. It is the composition to do. In this processing apparatus, since the condensing lens forms a sealed space in which the water flow is increased together with the nozzle, the condensing lens or the mounting portion of the condensing lens is a weak point in strength. For this reason, there is a limit to increasing the pressure of the liquid jet in the nozzle, which is not suitable for generating a higher-pressure jet water flow.

  In that respect, the processing apparatus described in Patent Document 2 is configured such that the laser beam introduced into the housing is reflected by the reflecting mirror and emitted from the housing, while the liquid jet passes through the housing from the injection port provided outside the housing. Therefore, the liquid can be ejected at a high pressure regardless of the strength of the housing. However, because there is a housing that introduces and reflects the laser beam, the liquid jet outlet cannot be brought close to the work piece, and therefore the water flow is dispersed when the liquid jet hits the work piece. It is assumed that the pressure is reduced and the processing efficiency is lowered, which is not practical.

  Although the workpiece is processed with the laser beam and the liquid jet as described above, it is difficult to increase the pressure of the liquid jet acting on the workpiece to a sufficient pressure in the past, and the processing with the liquid jet only assists the laser processing. This is the actual situation. However, if processing is possible with a liquid jet alone, it can be used separately from the laser beam depending on the application, or the auxiliary effect of the laser beam can be further enhanced, so that the pressure of the liquid jet can be increased. There has been a demand for technologies that can be used.

  Therefore, the present invention provides a laser jet processing apparatus that can greatly improve the pressure of the liquid jet, and that can be processed by the liquid jet alone, or can further enhance the auxiliary effect of the laser beam. It is intended to provide.

  The present invention includes a cylindrical nozzle having an injection port capable of simultaneously and coaxially emitting both a laser beam and a liquid jet containing abrasive grains, and a laser beam introducing section for introducing the laser beam into the nozzle. And a liquid jet introduction section for introducing a liquid jet containing abrasive grains into the nozzle. The liquid jet of the present invention is a fluid in which an appropriate amount of abrasive grains are mixed in a liquid and ejected at a high pressure. As abrasive grains, quartz, glass, diamond, fluorocarbon, polystyrene, or the like that does not absorb or reflect a laser beam. These organic substances are preferably used.

  According to the present invention, a liquid jet containing abrasive grains and a laser beam are introduced into a nozzle, and both of them are coaxially ejected from an ejection port of the nozzle and applied to a workpiece, thereby performing a required processing. . A laser beam introducing portion and a liquid jet introducing portion are connected to the nozzle, but other than these are unnecessary. Therefore, the nozzle can be constructed with a single material so as to have high strength, and by using a nozzle with improved strength, the pressure of the liquid jet introduced and ejected into the nozzle is greatly improved. Can be made. For this reason, the processing efficiency by the liquid jet can be improved, and as a result, the processing can be performed by the liquid jet alone. Further, since the nozzle can be prevented from being damaged even if abrasive grains are mixed in the liquid jet, it is possible to perform processing using a liquid jet including not only liquid but also abrasive grains. When a liquid jet mixed with abrasive grains is applied to a processed portion, a polishing effect is exhibited, thereby reducing surface roughness in laser processing and obtaining excellent processing quality.

  As a form of the laser beam introducing part and the liquid jet introducing part connected to the nozzle, a tubular one can be mentioned. It is a preferred embodiment of the present invention that at least one of these introduction parts is detachably attached to the nozzle. This is because, for example, when these introduction portions are damaged by contact of abrasive grains introduced into the nozzle, they can be replaced with new ones. Moreover, it is desirable to equip the laser beam introducing portion with a transparent shielding plate that prevents the liquid jet from entering the introducing portion. In this case, the shielding plate is highly likely to be damaged by the contact of abrasive grains. If the shielding plate is damaged, the transmission efficiency of the laser beam is reduced, so that it is necessary to replace the shielding plate with a new one. For this purpose, the laser beam introducing unit is used to replace the shielding plate with the laser beam introducing unit. The form which is detachably attached to the is preferable.

  The laser beam introduced into the nozzle from the laser beam introduction unit is oscillated from a laser oscillator such as a YAG laser oscillator, but refracts the laser beam in order to increase the degree of freedom of arrangement of the laser oscillator with respect to the nozzle. There is a case. Although the laser beam is refracted by a reflecting mirror, the reflecting mirror can be provided in the nozzle. In that case, if a reflecting mirror is provided in the nozzle, it can be provided without impairing the strength of the nozzle as described above.

  The form in which the reflecting mirror is provided in the nozzle is an example, and the reflecting mirror can also be provided in a laser beam introducing portion that is detachably attached to the nozzle. In this case, if the laser beam introduction part is detachably attached to the nozzle, the reflection mirror can be easily replaced with the laser beam introduction part even if the reflection mirror is damaged by abrasive grains. If the reflecting mirror is damaged, the reflection efficiency of the laser beam is lowered and the intensity of the laser beam is lowered. Therefore, replacement is necessary.

  Although the nozzle of the present invention is cylindrical, the inside is divided into a large-diameter channel on one end side and a small-diameter channel on the other end side by an inner-diameter restricting portion formed in the middle in the axial direction. The structure in which the injection port is arranged and the liquid jet introduction part is connected, the laser beam introduction part is connected to the small-diameter channel side, and the reflecting mirror is arranged is useful in the following points: The liquid jet is introduced into the large-diameter flow channel from the liquid jet introduction part and is ejected from the injection port. However, the presence of the inner-diameter restricting part makes it difficult for the liquid jet to enter the small-diameter flow channel on the side opposite to the injection port. The liquid jet is prevented from entering and backflowing. Further, in the case where the shielding plate is provided in the laser beam introducing portion, the liquid jet is blocked by the inner diameter restricting portion so that it does not easily hit the shielding plate, and the replacement time can be extended.

  According to the present invention, a nozzle that introduces both a laser beam and a liquid jet containing abrasive grains and emits them can be configured to have high strength. For this reason, the pressure of the liquid jet can be greatly improved, and in addition to this, the processing efficiency by the liquid jet can be improved by using the liquid jet mixed with abrasive grains, and the processing can be performed by the liquid jet alone. Is possible. Furthermore, since the processing portion can be simultaneously polished by the liquid jet containing abrasive grains, the surface roughness in laser processing is reduced, and excellent processing quality can be obtained.

Hereinafter, an embodiment according to the present invention will be described with reference to the drawings.
[1] Configuration of Laser Jet Processing Apparatus FIG. 1 shows a laser jet processing apparatus 1 according to an embodiment, and the apparatus 1 has a rectangular parallelepiped base 10 whose upper surface is horizontal. An XY movement table 11 that is movable in the horizontal X and Y directions is provided on the base 10, and a disk-shaped work table 12 is horizontally installed on the XY movement table 11. Yes. A workpiece to be laser-jet processed is held on the work table 12 and processed by a laser beam and a liquid jet emitted from a nozzle 50 disposed above. The work table 12 is a vacuum chuck type that sucks and holds a work by air suction. The workpiece to be processed is relatively brittle such as a semiconductor wafer or a substrate made of a thin resin plate, and the workpiece is subjected to required processing such as cutting and groove formation.

  The XY movement table 11 is a combination of an X-axis base 20 provided on the base 10 so as to be movable in the X direction and a Y-axis base 30 provided on the X-axis base 20 so as to be movable in the Y direction. It is configured. The X-axis base 20 is slidably attached to a pair of parallel guide rails 21, 21 extending in the X direction fixed on the base 10, and is moved in the X direction by the X-axis drive mechanism 22. The Y-axis base 30 is slidably attached to a pair of parallel guide rails 31, 31 extending in the Y direction fixed on the X-axis base 20, and is moved in the Y direction by a Y-axis drive mechanism 32.

  The work table 12 is rotatably or fixedly installed on the Y-axis base 30 and is moved in the X direction or the Y direction in accordance with the movement of the X-axis base 20 and the Y-axis base 30. By appropriately adjusting the moving direction and moving speed of the X-axis base 20 and the Y-axis base 30, not only linear movement in the X-direction and Y-direction but also the work table 12 is moved in a curved shape to perform curved machining. Can be done.

  A rectangular opening 12a is formed at the center of the work table 12, and a water receiving tank for receiving the liquid jet ejected from the nozzle 50 is provided in the Y-axis base 30 below the opening 12a. . The water receiving tank is connected to a circulation device that collects and cleans the liquid jet and then returns it to the nozzle 50 (the water receiving tank and the circulation device are not shown).

  A columnar column 13 extending upward in the vertical direction (Z direction) is fixed to one side surface of the base 10 (the side that is not visible in the right rear side in FIG. 1). The surface of the column 13 on the base 10 side is fixed. Is provided with a cylindrical machining shaft 40 extending along the Y direction to the work table 12. The machining shaft 40 is provided so as to be movable up and down along the column 13 and is moved up and down by a vertical drive mechanism (not shown) housed in the column 13. A nozzle 50 that emits a laser beam and a liquid jet downward is attached to the tip of the processing shaft 40 via a bracket 41.

  As shown in FIG. 2, the nozzle 50 is a cylindrical body in which a conical portion 52 extends from one end (lower end in FIG. 2) of a cylindrical portion 51 having a constant outer diameter, and the other end of the cylindrical portion 51 (in FIG. 2). The upper end is closed by an end plate portion 53, and an injection port 54 is opened at the tip of the conical portion 52. The nozzle 50 is attached to the bracket 41 with the injection port 54 below and the axial direction parallel to the Z direction. A laser beam introducing tube (laser beam introducing portion) 60 is detachably inserted at the upper end of the cylindrical portion 51 in the attached state, and a liquid jet introducing tube (liquid jet introducing portion) 70 is detachably inserted at the lower end. It is installed. Each introduction pipe 60 and 70 is cylindrical and extends in the radial direction of the nozzle 50 in a state of being parallel to each other. In FIG. 1, the introduction pipes 60 and 70 are not shown.

  A laser oscillator (not shown) such as a YAG laser oscillator is connected to the laser beam introducing tube 60, and the laser beam oscillated by this laser oscillator passes through the laser beam introducing tube 60 coaxially into the nozzle 50. It has been introduced. As the laser beam oscillated by the laser oscillator, for example, one having an output of 1 to 5 W and a wavelength of 1064 nm is preferably used.

  As shown in FIG. 3, the laser beam introducing tube 60 mainly includes a cylindrical main body 61, and a reflecting mirror 63 is provided at the tip of the main body 61 via a stay 62. The stay portion 62 is formed by cutting out a part of the main body portion 61, has a circular arc cross section, and extends in the axial direction of the main body portion 61. A reflecting mirror 63 formed in a concave shape is provided integrally with the stay portion 62 at the tip of the stay portion 62. The laser beam introduced into the nozzle 50 through the laser beam introducing tube 60 is condensed by the reflecting mirror 63, is converted into a thin beam, and is refracted downward by 90 °. (L in FIG. 2 indicates a laser beam). In addition, a transparent shielding plate 64 that closes the tip opening is fixed to the tip of the main body 61. The shielding plate 64 prevents the liquid jet introduced into the nozzle 50 from entering the laser beam introduction tube 60 and backflowing. The laser beam introducing tube 60 is mounted on the cylindrical portion 51 of the nozzle 50 so that the laser beam condensed by the reflecting mirror 63 and reflected in a thin beam shape is emitted coaxially from the emission port 54. .

  Connected to the liquid jet introduction pipe 70 is a liquid jet supply device (not shown) for supplying water into which the abrasive grains are mixed at an appropriate ratio and supplying the water into the introduction pipe 70. A liquid jet containing the supplied abrasive grains is introduced into the nozzle 50 through the liquid jet introduction pipe 70. The abrasive is preferably made of quartz, glass, diamond, or an organic material such as fluorocarbon or polystyrene, which does not absorb or reflect the laser beam, and is not preferably made of metal. The size of the abrasive grains, that is, the abrasive particle diameter, is preferably about one fifth or less of the wavelength of the laser beam introduced from the laser beam introducing tube 60 into the nozzle 50, and more preferably one tenth or less. When the abrasive grain size is about 1/5 to 1/10 of the wavelength of the laser beam, the mixing ratio of the abrasive grains to water is preferably 10% or less, and more preferably 5% or less. The water pressure is preferably 50 MPa or more in order to obtain a processing effect by a liquid jet, and more preferably about 200 MPa in order to obtain a sufficient processing effect.

[2] Operation of Laser Jet Processing Apparatus The configuration of the laser jet processing apparatus 1 of the present embodiment has been described above. According to the processing apparatus 1, the work is attracted and held on the work table 12, the processing shaft 40 is lowered with respect to the work to bring the nozzle 50 closer, and the laser beam emitted from the nozzle 50 downward in the form of a beam. By moving the XY moving table 11 appropriately while simultaneously applying the liquid jet, the workpiece is subjected to required processing such as cutting and groove formation.

  In the nozzle 50, the liquid jet introduced from the liquid jet introduction pipe 70 fills the nozzle 50 and further increases the pressure, and the liquid jet is ejected downward from the ejection port 54 in the form of a beam and strikes the workpiece. On the other hand, the laser beam introduced from the laser beam introducing tube 60 is refracted by 90 ° by the reflecting mirror 63 and coaxially guided into the liquid jet emitted from the emission port 54, and emitted from the emission port 54 to irradiate the workpiece. Is done. The workpiece is melted with a laser beam and processed, and the liquid jet functions to remove processing debris generated by the heat of the laser beam, for example, to prevent reattachment, and to cool the processing point of the laser beam.

  According to the laser jet processing apparatus 1 of the present embodiment, the laser beam introducing tube 60 and the liquid jet introducing tube 70 are attached to the nozzle 50, but there is no need to add other components to the nozzle 50. Therefore, the nozzle 50 itself can be configured integrally with a single material and having high strength. For example, when the nozzle 50 is made of a highly durable metal such as stainless steel and has improved strength, the pressure of the liquid jet introduced and ejected into the nozzle 50 can be greatly improved. For this reason, the pressure of the liquid jet which hits a workpiece | work can be raised. Furthermore, since the abrasive grains can be mixed with the liquid jet as the strength of the nozzle 50 is improved, cutting such as cutting can be performed even with the liquid jet alone, coupled with the improvement in pressure. Furthermore, when a liquid jet mixed with abrasive grains is applied to the processed portion, a polishing effect is exhibited, thereby reducing surface roughness in laser processing and obtaining excellent processing quality.

  Further, since the abrasive grains in the liquid jet are scattered at a high pressure in the nozzle 50, there is a high possibility that the abrasive grains hit the reflecting mirror 63 and the shielding plate 64 and be damaged. If the reflecting mirror 63 is damaged, the reflection efficiency of the laser beam is lowered and the intensity of the laser beam is lowered, so that replacement is necessary. Further, when the shielding plate 64 is damaged, the transmission efficiency of the laser beam is lowered and the strength is also lowered. Therefore, if the reflecting mirror 63 or the shielding plate 64 is damaged, the laser beam introducing tube 60 may be removed from the nozzle 50 and replaced with a new one. In the present embodiment, the reflecting mirror 63 and the shielding plate 64 can be easily replaced by exchanging the reflecting mirror 63 and the shielding plate 64 together with the laser beam introducing tube 60 in this way.

[3] Another form of nozzle FIGS. 4 and 5 show another form of nozzle. These nozzles have the same external shape as the nozzle 50, but differ in internal structure.
In the nozzle 50 shown in FIG. 4, a step portion 55 formed in a plane perpendicular to the axial direction is formed in the middle portion in the axial direction, and a flow path extending in the axial direction is formed by the step portion 55. The large-diameter channel 56 on the injection port 54 side and the small-diameter channel 57 are divided. These flow paths 56 and 57 have a circular cross section and are formed coaxially with the nozzle 50.

  The liquid jet introduction tube 70 is attached so as to communicate with the large-diameter channel 56, and the laser beam introduction tube 60 provided with the reflecting mirror 63 is attached so as to communicate with the small-diameter channel 57. The laser beam introducing tube 60 in this case does not have the stay portion 62, and the reflecting mirror 63 is directly provided on the main body portion 61.

  According to the nozzle 50, the laser beam reflected by the reflecting mirror 63 (indicated by the symbol L in FIG. 4) is ejected from the small-diameter channel 57 through the large-diameter channel 56 through the ejection port 54, and the liquid jet is ejected from the large-diameter channel 56. Through the injection port 54. In this case, the liquid jet is unlikely to enter the small-diameter channel 57 due to the stepped portion, so that the reflector 63 and the shielding plate 64 are not easily damaged by the abrasive grains, and the replacement time of the laser beam introducing tube 60 is extended. Has the advantage of being able to.

  In the nozzle 50 shown in FIG. 5, a reflecting mirror 58 that reflects the laser beam introduced from the laser beam introducing tube 60 toward the exit 54 is integrally formed on the upper end surface. The reflecting mirror 58 is formed in a concave shape like the reflecting mirror 63 of the above embodiment, and is a laser beam (indicated by symbol L in FIG. 5) introduced into the nozzle 50 through the laser beam introducing tube 60. Is condensed by the reflecting mirror 58, converted into a thin beam, and refracted 90 ° downward. For this reason, the laser beam introducing tube 60 does not include the stay portion 62 and the reflecting mirror 63 as shown in FIG. 3, and has a configuration in which the shielding plate 64 is only provided at the tip of the main body portion 61. When the reflecting mirror 58 is formed integrally with the nozzle 50 as described above, the reflecting mirror 58 can be provided without impairing the strength of the nozzle 50.

1 is an overall perspective view of a laser jet machining apparatus according to an embodiment of the present invention. It is a longitudinal cross-sectional view of the nozzle which inject | emits a laser beam and a liquid jet. It is a perspective view of the front-end | tip part of the laser beam introduction tube with which a nozzle is mounted | worn. It is a longitudinal cross-sectional view which shows the other form of a nozzle. It is a longitudinal cross-sectional view which shows the further another form of a nozzle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laser jet processing apparatus 50 ... Nozzle 54 ... Injection port 55 ... Step part (inner diameter aperture | diaphragm | squeeze part)
56 ... Large-diameter channel 57 ... Small-diameter channel 60 ... Laser beam introducing tube 63 ... Reflecting mirror 70 ... Liquid jet introducing tube L ... Laser beam

Claims (7)

A cylindrical nozzle having an injection port capable of simultaneously and coaxially emitting both a laser beam and a liquid jet containing abrasive grains;
A laser beam introducing section for introducing a laser beam into the nozzle;
A laser jet machining apparatus comprising: a liquid jet introduction unit that introduces a liquid jet containing abrasive grains into the nozzle.   2. The laser jet machining apparatus according to claim 1, wherein the laser beam introducing section and the liquid jet introducing section are tubular.   3. The laser jet machining apparatus according to claim 1, wherein at least one of the laser beam introducing section and the liquid jet introducing section is detachably attached to the nozzle.   3. The laser according to claim 1, wherein a reflecting mirror that reflects the laser beam introduced into the nozzle from the laser beam introducing portion toward the exit is disposed on the inner surface of the nozzle.・ Jet processing equipment.   The laser beam introducing portion is detachably attached to the nozzle, and the laser beam introducing portion is provided with a reflecting mirror that reflects the laser beam introduced into the nozzle toward the exit port. The laser jet processing apparatus according to claim 3. The inside of the nozzle is divided into a large-diameter channel on one end side and a small-diameter channel on the other end side by an inner diameter restricting portion formed in the intermediate portion in the axial direction,
The injection port is arranged on the large diameter channel side and the liquid jet introduction part is connected,
6. The laser jet machining apparatus according to claim 4, wherein the laser beam introducing section is connected to the small diameter flow path side and the reflecting mirror is disposed.   The laser jet machining apparatus according to claim 1, wherein the liquid jet is a liquid in which quartz is dispersed and mixed in a predetermined ratio as the abrasive grains.

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