JP4778031B2 - Laser processing machine - Google Patents

Description

  The present invention relates to a laser processing machine for processing a workpiece placed on a table by condensing a laser output from a laser oscillator by an fθ lens.

  As a laser processing machine that cuts an ultra-thin plate, there is a technology for processing a workpiece while the workpiece is sandwiched between a highly slippery upper workpiece holding member and a highly slippery lower fixed surface plate (patent) Reference 1).

  Moreover, many printed circuit boards processed by laser have a thickness of less than 1 mm and have low rigidity. Therefore, a large number of holes communicating with the internal space are formed on the surface of the processing table, the space is connected to a negative pressure source, and the work is fixed to the table surface by suction. In either case, the workpiece could be supported on the table almost flatly.

JP-A-10-328867

  In recent years, there is an increasing demand for laser processing of not only a printed board having a thin plate thickness but also a multilayer printed board having a large plate thickness (for example, 2 mm or more). A multilayer printed circuit board is manufactured by laminating a plurality of double-sided printed circuit boards through an insulator, but warpage may occur in the manufacturing process.

  In the case of the technique of Patent Document 1, the work is sandwiched between the upper work piece holding member and the highly-slidable lower fixed surface plate, but the work moves between them. If there was a warp, it could not be processed.

In addition, when the workpiece has high rigidity, the inside of the substrate (laser-processed portion) cannot be completely warped simply by vacuum-sucking the substrate and clamping the four corners of the substrate. When the laser warpage is greater than the depth of focus of the fθ lens (for example, the depth of focus is ± 30 to 100 μm for the CO ₂ laser and the depth of focus is ± 100 to 200 μm for the UV laser), the accuracy is high. Could not process well.

  An object of the present invention is to solve the above-mentioned problems and to provide a laser processing machine that can accurately process even a warped workpiece.

The present invention (see, for example, FIG. 1, FIG. 2 , FIG. 3 and FIG. 4), an XY table (2) for moving a machining table (3) on which a work (30) is placed in a horizontal direction;
an fθ lens (10);
A hollow portion (56) disposed between the fθ lens (10) and the processing table (3) and including a processing region (57) on the workpiece (30) defined by the fθ lens (10). ) Formed with a pressure plate (55),
The output laser from the laser oscillator (5) and (6) is condensed by the fθ lens (10) is placed on said machining table (3) through the hollow portion (56) of the pressure plate (55) in the laser processing machine for processing a respective processing region of the workpiece (30),
When there is a next machining area after the machining in the machining area in the work (30), the pressure plate (55) is raised to the standby position, and the XY table (2) A control device that positions the center of the next processing area on the main axis of the fθ lens (10) and lowers the pressure plate (55) to perform the laser processing until the next processing area disappears. (70)
There exists in the laser processing machine (100) characterized by this.

In the laser processing machine (100), the distance between the rear focal point of the fθ lens (10) and the tip (55a) of the pressure plate (5 5 ) that contacts the workpiece (30) is measured. A measuring unit (60),
The control device (70) moves the fθ lens (10) in the principal axis direction when the distance obtained by the measurement of the measurement unit (60) is different from a predetermined value prior to processing of the workpiece (30). By moving the distance to a predetermined value,
It is characterized by this.

Further, the laser processing machine in (100), to have a said pressure plate (55) pressure capable of changing the adjustment portion (53),
It is characterized by this.

  In addition, although the code | symbol in the said parenthesis is for contrast with drawing, this is for convenience for making an understanding of invention easy, and has no influence on the structure of a claim. It is not a thing.

  According to the present invention, even a warped workpiece can be processed with a laser with high accuracy.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a front view of a laser beam machine 100 according to an embodiment of the present invention. Moreover, FIG. 2 is an AA arrow view in FIG.

  The laser processing machine 100 includes a bed 1, an XY table 2, and a processing table 3. The XY table 2 is movable on the bed 1 in the horizontal X and Y directions. On the XY table 2, a plurality of holes (not shown) connected to a hollow portion (not shown) are formed on the surface, and the vacuum portion is provided by connecting the hollow portions (not shown) to a vacuum source. The table 3 is fixed. A clamp (not shown) that fixes the workpiece 30 to the machining table 3 is disposed around the machining table 3. The workpiece 30 is, for example, a printed circuit board, and warpage may occur during the manufacturing process. The gate-shaped column 4 is fixed to the bed 1.

  The laser processing machine 100 includes a laser oscillator 5, mirrors 7 and 8, a processing head 11, and a laser irradiation unit 20. The laser oscillator 5 is mounted on the column 4, and mirrors 7 and 8 and a laser irradiation unit 20 are disposed on the optical path of the laser oscillator 5. The laser irradiation unit 20 includes a scanner unit 9 that positions a pair of mirrors (not shown) in a rotatable manner, and an fθ lens 10. When the diameter of the fθ lens 10 is D, the processing area (scanning area) is a square inscribed in a circle with the diameter D, that is, the length of one side is not more than D / √2 square, and is usually 50 mm or 30 mm square.

  The scanner unit 9 is composed of two scanners 9x and 9y having the same configuration. The axis of the motor output shaft (not shown) in the scanner 9x and the axis of the motor output shaft in the scanner 9y are orthogonal (so-called torsional). Direction). The scanner 9x scans the laser 6 in the X-axis direction in the processing area (scanning area) on the workpiece 30, and the scanner 9y scans the laser 6 in the Y-axis direction. The laser irradiation unit 20 is supported by the processing head 11. The machining head 11 can be positioned on the column 4 in the vertical direction (Z direction) in the drawing by means not shown. The mirror 8 is disposed at a position facing the scanner 9x on the processing head 11.

  Further, the laser processing machine 100 includes a pressurizing device 50 and a control device 70 that controls each unit. The pressurizing device 50 includes a pair of cylinders 51, a compressed air source 52, a pressure regulator (a pressure reducing valve) 53 as an adjusting unit, a switching valve 54, and a pressurizing plate 55 as a pressurizing unit.

  The pair of cylinders 51 are fixed to the column 4 so as to sandwich the machining head 11. The cylinder 51 is connected to a compressed air source 52 via a pressure regulator 53 and a switching valve 54. The pressure plate 55 is held by the cylinder 51 and is movable in the direction of arrow Z in FIG. As shown in FIG. 2, the tip portion 55 a of the pressure plate 55 facing the workpiece 30 has a cross-sectional shape similar to that of the square pipe, and the axis of the hollow portion 56 is coaxial with the main axis of the fθ lens 10. . The hollow portion 56 is formed so as to penetrate not only the tip portion 55a but also the entire pressure plate 55 in the direction of arrow Z in FIG.

  The hollow portion 56 of the pressure plate 55 is formed larger than the processing region 57 whose cross-sectional size is determined by the fθ lens 10. Specifically, the length of the side of the hollow portion 56 is longer than the length of one side of the processing region 57 (region indicated by a two-dot chain line in FIG. 2) determined by the diameter of the fθ lens 10 and includes the processing region 57. Length. By the pressure plate 55 in which the hollow portion 56 is formed, the periphery of the machining area 57 of the workpiece 30 is urged to the machining table 3, and the warpage of the machining area 57 can be effectively eliminated.

  The pressure regulator 53 can adjust the pressure of the air supplied to the cylinder 51 from the compressed air source 52 and change the pressure applied to the pressure plate 55. The switching valve 54 has a solenoid and can be switched between a valve open state in which the pressure regulator 53 and the cylinder 51 communicate with each other and a valve closed state in which the pressure regulator 53 side is closed and the cylinder 51 side is opened. When the solenoid is energized by the device 70, the valve is switched to the closed state, and when the controller 70 is de-energized, the valve is switched to the open state.

  Therefore, when the switching valve 54 is opened, the air whose pressure is adjusted by the pressure regulator 53 is supplied to the cylinder 51, and the workpiece 30 is attached to the processing table 3 by the pressurizing plate 55 of the pressurizing device 50. You can When the switching valve 54 is closed, the supply of air to the cylinder 51 is shut off and the cylinder 51 side is opened, so that the pressure plate 55 can be moved away from the workpiece 30. The workpiece 30 can be moved in the direction of the arrow XY.

  In addition, the laser processing machine 100 includes a measurement unit 60 that measures the distance between the rear focal point of the fθ lens 10 and the tip 55a that contacts the workpiece 30 of the pressure device 50. The measuring unit 60 includes a dog 61 and a scale 62.

  A dog 61 is arranged on the side of the pressure plate 55 facing the processing head 11. A scale 62 is disposed at a position facing the dog 61 of the processing head 11. The scale 62 reads the position of the dog 61, that is, the relative position of the front end portion 55 a (lower end) of the pressure plate 55 with respect to the processing head 11. Usually, the rear focal plane of the fθ lens 10 is made to coincide with the surface of the work 30, and therefore, the position in the arrow Z direction of the front end portion 55 a of the pressure plate 55 is the rear focal plane (rear focal plane) of the fθ lens 10. The relative distance L between the two is set to 0 (predetermined value) when it coincides with the surface perpendicular to the main axis of the fθ lens 10.

  It is optimal that the predetermined value is 0, but the value is not limited to 0, and the predetermined value can be set within the range of the focal depth of the fθ lens 10.

  Next, the operation of the laser beam machine 100 according to the present embodiment will be described. The processing head 11 and the pressure plate 55 are in the standby position. When the processing head 11 is in the standby position, the rear focal plane of the fθ lens 10 is above the processing table 3 by a predetermined distance H. When the pressure plate 55 is in the standby position, the tip 55a of the pressure plate 55 is above the processing table 3 by a predetermined distance h.

  FIG. 3 is a flowchart showing the operation of the laser beam machine 100 in the embodiment of the present invention.

  The workpiece 30 previously placed on the machining table 3 is fixed on the machining table 3 by a clamp (not shown) by the user. The reason for fixing the workpiece 30 in this way is to prevent the workpiece 30 from moving on the machining table 3 in the direction of the arrow XY in FIG. 1, and one or two locations are fixed.

  In addition, the pressure regulator 53 is set in advance so that the pressure P is applied when the pressure plate 55 pressurizes the workpiece 30. If the pressure P is excessive, the surface of the work 30 may be damaged. Therefore, the necessary pressure P is determined in advance depending on the rigidity of the work 30, specifically the material of the work 30 and the degree of warpage. Select and set. Thereby, the work 30 can be urged with a pressure P suitable for the work 30.

  When a processing start button (not shown) is turned on, the control device 70 moves the XY table 2 and positions the center of the processing region 57 to be processed first on the main axis of the fθ lens 10 (step S10). Next, the control device 70 lowers the pressure plate 55 (step S20). More specifically, the control device 70 controls the switching valve 54 to an open state, and supplies the air whose pressure has been adjusted by the pressure regulator 53 to the cylinder 51. Thereby, prior to laser processing of the workpiece 30, the workpiece 30 is biased to the processing table 3 by the pressurizing device 50. Then, the machining area 57 to be machined by the laser of the workpiece 30 is pressed against the machining table 3 by the pressure plate 55 of the pressure device 50 and becomes almost flat. For example, as shown in FIG. 4A, the workpiece 30 is deformed into a convex shape, or the workpiece 30 is deformed into a concave shape as shown in FIG. The portion pressurized by the 30 pressure plates 55 becomes substantially flat.

  Next, when a predetermined time elapses, the control device 70 lowers the machining head 11 in the arrow Z direction (step S30), and has the relative distance L obtained by the measuring unit 60 become 0, which is a predetermined value? It is determined whether or not (step S40). When the relative distance L obtained by the measurement is different from 0 (procedure S40: No), the relative distance L is lowered by moving the processing head 11 supporting the fθ lens 10 in the arrow Z direction (moving in the main axis direction). Is matched with 0.

  When the relative distance L becomes 0 (procedure S40: Yes), laser processing is started (procedure S50).

  Since the content of step S50 is the same as the conventional one, detailed description is omitted, but the laser 6 is irradiated to the processing region 57 of the workpiece 30 through the hollow portion 56 of the pressure plate 55. At this time, since the processing region 57 of the workpiece 30 is pressed against the processing table 3 by the pressure plate 55, the warping of the processing region 57 of the workpiece 30 is performed while the workpiece 30 is pressed against the processing table 3 by the pressure plate 55. Can be eliminated. Therefore, the workpiece 30 can be laser processed with high accuracy.

  Since the relative distance L is 0, the rear focal plane of the fθ lens 10 and the surface of the work 30 coincide with each other, and the work 30 can be laser processed with higher accuracy.

  Next, when the machining in the machining area is finished (procedure S60), the control device 70 checks whether or not there is a next machining area (procedure S70), and if there is a next machining area (procedure S70: Yes). ) Moves (lifts) the pressure plate 55 to the standby position (procedure S80), and then proceeds to the process of procedure S10. When the machining of the workpiece 30 is completed (procedure S70: No), the pressure plate 55 is moved to the standby position (procedure S90), and the machining is terminated.

  In order to prevent the surface of the work 30 from being scratched, a material that does not damage the work 30 (for example, a hard synthetic resin) may be disposed on the surface of the pressure plate 55 that contacts the work 30. Good.

  When the rigidity of the work 30 is small, the work 30 may be fixed to the processing table 3 by suction as in the conventional case.

It is a front view of the laser beam machine in the embodiment of the present invention. It is an AA arrow line view in FIG. It is a flowchart which shows operation | movement of the laser processing machine in embodiment of this invention. It is a figure which shows operation | movement of a pressurization plate.

Explanation of symbols

3 Processing table 5 Laser oscillator 10 fθ lens 30 Work piece 50 Pressurizing device 53 Adjustment unit (pressure regulator)
55 Pressurizing plate 55a Tip portion 56 Hollow portion 57 Processing area 60 Measuring portion
70 Control device 100 Laser processing machine

Claims (3)

An XY table for horizontally moving a processing table on which a workpiece is placed;
an fθ lens;
A pressure plate disposed between the fθ lens and the processing table and having a hollow portion having a size including a processing region on the workpiece defined by the fθ lens,
The laser output from the laser oscillator is condensed by the fθ lens, the laser processing machine for processing a respective processing region of the workpiece placed on the work table through a hollow portion of the pressure plate,
When there is a next machining area after the machining in the machining area in the workpiece, the pressure plate is raised to a standby position, and the center of the next machining area in the workpiece is set to the main axis of the fθ lens by the XY table. A control device is provided that performs a machining operation for performing laser machining by positioning the upper plate and lowering the pressure plate until there is no next machining area.
A laser processing machine characterized by that. A measurement unit that measures the distance between the rear focal point of the fθ lens and the tip of the pressure plate that contacts the workpiece;
When the distance obtained by the measurement of the measurement unit is different from a predetermined value prior to processing the workpiece , the control device moves the fθ lens in a principal axis direction to set the distance to a predetermined value. Match,
The laser beam machine according to claim 1. To have a pressure capable of changing the adjustment of the pressure plate,
The laser processing machine according to claim 1 or 2, wherein

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