JP2017217682A - Laser beam machining device and laser beam machining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that machining position deviation on a work-piece occurs due to influence of a tilt angle of a laser beam transmitted by a condensing lens in order to perform machining while focusing the laser beam on the inner side than a surface of the work-piece upon LTH machining (penetration machining) with respect to glass penetration electrode work-piece or the like when performing perforation of the work-piece by means of a laser beam machining device.SOLUTION: A laser beam machining device includes: a laser oscillator which receives a laser pulse output instruction signal and emits a laser beam; a galvano device which receives an instruction position information, is operated and performs positioning of the laser beam to a machining position; a control device which controls at least the laser oscillator and the galvano device; and a defocus correction part which corrects the instruction position information in accordance with a defocus amount.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laser processing apparatus and a laser processing method that perform drilling and the like on a substrate using a laser. In particular, the present invention relates to prevention of machining position deviation caused by defocus machining used in the apparatus.

  In recent years, with the miniaturization of parts, high integration, and the formation of composite modules, drilling of workpieces has become increasingly precise, and in order to respond to this, drilling using lasers has increased.

  When drilling a workpiece with a laser processing apparatus, in the BVH processing (non-penetrating processing) on a resin substrate or the like, the processing is performed by focusing the laser beam on the surface of the workpiece. On the other hand, in the case of LTH processing (penetration processing) for a glass through electrode workpiece, etc., defocusing is performed by focusing the laser beam on the inner side of the surface of the workpiece. Processing is performed. In this case, due to the influence of the tilt angle of the laser light transmitted through the condenser lens, there is a problem that the processing position shift on the workpiece occurs and the processing hole does not penetrate.

  In response to this problem, conventional laser processing apparatuses efficiently process holes with excellent quality by changing the energy intensity per unit area of the laser beam by changing the distance between the printed circuit board and the f · θ lens. The laser processing method which can be performed is disclosed (for example, refer patent document 1).

JP 2005-159898 A

  However, an actual laser processing apparatus has a problem that a result as the theoretical value cannot be obtained due to individual differences of individual parts, assembly errors between parts, and the like.

  Therefore, in the laser processing apparatus of the present invention, the defocus processing is actually performed on the workpiece, and correction data for correcting the processing position deviation generated according to the defocus amount is obtained in advance, and the correction data By correcting the machining position based on the above, it is an object to prevent the occurrence of machining position deviation during defocus machining.

  In order to solve the above-described problems, a laser processing apparatus according to the present invention includes a laser oscillator that emits a laser beam in response to a laser pulse output command signal; A galvano device that positions light, a control device that controls at least the laser oscillator and the galvano device, and a defocus correction unit that corrects the command position information in accordance with a defocus amount.

In addition, the laser processing method of the present invention is provided with correction data for correcting a processing position shift that occurs in accordance with the defocus amount, and a laser beam command for a desired defocus amount based on the correction data. When the position information is corrected and the laser beam is emitted to the corrected position for drilling, the workpiece surface is drilled, the workpiece is inverted, and the back of the workpiece Drilling is performed at the same position on the surface.

  With the laser processing apparatus of the present invention, it is possible to prevent a processing position shift when performing defocus processing. Further, in the laser processing method of the present invention, it is possible to prevent a processing position shift on the workpiece and to penetrate the processing hole.

Schematic configuration diagram of a laser processing apparatus according to an embodiment of the present invention Schematic configuration diagram of a control device of a laser processing apparatus according to an embodiment of the present invention Explanatory drawing of the concept of the process position correction in the laser processing apparatus which concerns on embodiment of this invention Flowchart of control algorithm in laser processing apparatus according to an embodiment of the present invention Explanatory drawing of how to obtain | require the correction coefficient in the laser processing apparatus which concerns on embodiment of this invention Explanatory drawing of the example of a process using the laser processing apparatus concerning embodiment of this invention Explanatory drawing of the other example of a process using the laser processing apparatus concerning embodiment of this invention

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same components are denoted by the same reference numerals, and description thereof may be omitted. Further, the X axis, the Y axis, and the Z axis shown in the drawings indicate directions orthogonal to each other. Here, the Z axis is the vertical direction corresponding to the top and bottom, and the coordinate axes in each figure are drawn so as to correspond to the directions of the respective fields of view.

<Configuration of laser processing equipment>
FIG. 1 is a schematic configuration diagram of a laser processing apparatus according to an embodiment of the present invention. The laser processing apparatus 100 includes a laser oscillator 110, a galvano scanner 112, a condenser lens 113, a processing table 116, and a control device 200. The laser oscillator 110 receives the laser pulse output command signal 120 output from the control device 200 and emits laser light 111.

  As a system of the laser oscillator 110, an appropriate one such as a YAG laser or a carbon dioxide gas laser may be selected from energy necessary for processing, a laser wavelength, and the like. In this embodiment, an example using a sealed RF excited carbon dioxide laser will be described. This is because a high peak output can be obtained with a short pulse required when drilling a substrate at high speed with a laser beam.

  Laser light 111 emitted from the laser oscillator 110 is guided to the galvano scanner 112. The galvano scanner 112 starts operation upon receiving a galvano operation command signal 121 from the control device 200, and guides the laser beam 111 to a predetermined processing position 114 of the workpiece 115. Specifically, the galvano mirror 124 in the X-axis direction scans the laser beam 111 in the X-axis direction, and the galvano mirror 125 in the Y-axis direction scans the laser beam 111 in the Y-axis direction. Each of the galvanometer mirrors 124 and 125 is adapted to swing an angle by a motor provided in each.

The galvano controller 123 controls the deflection angle of the galvanometer mirror 124 in the X-axis direction and the galvanometer mirror 125 in the Y-axis direction according to the processing position data by the processing program. The laser beam 111 positioned by the galvano scanner 112 is converted into a condenser lens 113 (f
(also referred to as a θ lens). The condenser lens 113 receives the condenser lens position command signal 122 from the control device 200 and operates in the Z-axis direction.

  The workpiece 115 is a sheet-like member such as a substrate, a green sheet, a film, or a thin metal plate. The workpiece 115 is placed on the processing table 116. The machining table 116 can be driven in the X-axis direction and the Y-axis direction, and can move the workpiece from the machining area that can be scanned by the galvano scanner 112 to another different machining area.

  The operation of the laser processing apparatus of the present invention configured as described above will be described.

  The laser oscillator 110 is sufficiently warmed up as necessary. The workpiece 115 is placed and fixed on the processing table 116, and is moved to a predetermined processing area. In accordance with the processing program, the galvano scanner 112 is positioned so that the laser beam 111 is irradiated to a predetermined processing position 114. The laser beam 111 is irradiated as a pulse, and the workpiece 115 is processed, for example, drilling. The galvano scanner 112 is positioned so that the next processing position 114 is irradiated with the laser beam 111. The workpiece 115 is processed by irradiating the laser beam 111 as a pulse.

  The above cycle is repeated and the processing in a predetermined processing area is completed. Thereafter, the workpiece 115 is moved to the next machining area, the same machining is performed, and the machining of the entire workpiece 115 is completed.

<Configuration of control device>
The control device 200 has a function of controlling at least the laser oscillator 110, the galvano scanner 112, and the condenser lens 113. Further details will be described with reference to the drawings.

  FIG. 2 is a block diagram of the control device according to the embodiment of the present invention. The control device 200 includes a main software processing unit 211, a parameter storage unit 212, a machining data analysis unit 213, a laser pulse command unit 214, a defocus correction unit 215, a defocus setting unit 216, and a machining hole position measurement. A unit 217, a galvano position command unit 220, and a condenser lens position command unit 221.

  Note that these components are obtained by blocking the functions of the control device 200. It may be configured by hardware that is individually independent, or may be configured by a combination of an interface and software. In addition, these components are shown for explaining the characteristic configuration and operation of the present invention, among the functions of the control device 200, and naturally have other control functions of the laser processing device 100. Yes.

  The parameter storage unit 212 stores various parameters that are determined in advance before the operation of the laser processing apparatus, and includes a defocus amount parameter. The processing data analysis unit 213 analyzes a processing program for processing the workpiece and converts it into processing data for controlling the laser oscillator 110, the galvano scanner 112, and the condenser lens 113.

  The laser pulse command unit 214 outputs a laser pulse output command signal 120 to the laser oscillator 110 according to the machining data converted by the machining data analysis unit 213. The laser pulse output command signal 120 is a pulse signal, and an optimum pulse width is determined based on the relationship between the laser power and the material and thickness of the workpiece.

The defocus correction unit 215 performs a correction operation on the galvano position command of the machining data analysis unit 213 based on the defocus amount and outputs the calculation result to the galvano position command unit 220. The galvano position command unit 220 receives the calculation result from the defocus correction unit 215 and outputs a galvano operation command signal 121 to the galvano scanner 112.

  The defocus setting unit 216 outputs the defocus amount parameter stored in the parameter storage unit 212 to the condenser lens position command unit. The processing hole position measurement unit 217 measures the position of the processing hole on the workpiece. The main software processing unit 211 controls the above components in accordance with a program, and also has a timer function inside, and simultaneously performs control with the passage of time.

  Here, the concept of correction in the defocus correction unit 215 will be described with reference to FIG. In FIG. 3A, when the condensing lens 113 is at the first position 310, the laser beam 314 is condensed at a point a on the processed surface of the workpiece (hereinafter, this state is referred to as just focus). Call).

  When the condenser lens 113 is at a position 311 moved downward by the distance D, the laser beam 315 is condensed at the point b which is a position below the distance D from the point a (hereinafter, this state). Is called defocus). This distance D is called a defocus amount.

  In the case of defocusing, due to the influence of the laser beam tilt angle 313, the processing hole position is shifted on the processing surface of the workpiece by a distance W1, which is the difference between the points a and c. Therefore, as shown in FIG. 3B, a distance W2 corresponding to the distance W1 is calculated by a correction arithmetic expression described later, and the processing position is corrected by changing the direction of the laser beam by the galvano scanner 112, so that the laser is obtained. Since the light 321 can be condensed at the point a, the processing hole position does not shift.

<Control algorithm>
FIG. 4 is a flowchart showing a control algorithm of the laser processing apparatus according to the embodiment of the present invention.

  As a step before performing actual machining, first, the defocus amount h is set inside the workpiece, and laser machining is performed at the position of the command value (step S50). The machining position is measured by the machining hole position measuring unit 217. A difference between the measured value and the command value is used as a machining hole position error, and defocus correction coefficients Kx and Ky (details will be described later) for correcting this are obtained (step S51).

  Next, an actual machining program is analyzed, and Px and Py are read out as command values for the first machining position (step S52). Based on the defocus correction coefficient, defocus correction values fx and fy are calculated as the corrected processing positions for the command value (step S53).

  Using the defocus correction value as a new command value, a galvano operation command is issued to the galvano scanner. After completion of the galvano operation, laser light is irradiated to perform drilling (step S54).

  The operations in steps S52 to S54 are repeatedly executed until there is no machining data included in the machining program (step S55).

Here, a detailed calculation method of the defocus correction coefficient will be described with reference to FIG. FIG. 5 shows a predetermined galvano scan area (range in which laser processing can be performed only by the operation of the galvano scanner) of the workpiece. FIG. 5 (a) shows coordinates in the XY directions, and FIG. 5 (b).
Indicates coordinates in the Z direction.

  The length of the galvano scan area 410 in the X-axis direction is Lx, the length in the Y-axis direction is Ly, and the coordinates of the center point of the galvano scan area 410 are G (0, 0).

  For convenience, the correction in the X-axis direction will be described first. A defocus amount h is set inside (downward) from the surface 431 of the workpiece, laser processing is performed using the point A (Lx / 2, 0) as a command value, and the processing position is set to the processing hole position measuring unit 217. To measure. Assuming that the difference between the measured value and the command value in the X-axis direction is the machining hole position error ex, the following equation is established if the defocus correction coefficient is Kx.

ex = (Lx / 2) × Kx × h
When deformed, the defocus correction coefficient Kx is
Kx = ex / (Lx / 2 × h)
It becomes.

Next, considering the machining hole position error amount sx in the X-axis direction at a point P (px, 0) at an arbitrary machining position in the galvano scan area 410,
sx = px × Kx × h
= Px × ex / (Lx / 2 × h) × h
= Px x ex / (Lx / 2)
It becomes.

  Therefore, the original processing position is corrected by this sx, and a defocus correction value fx is calculated as a new position by the following equation.

fx = px-sx
= Px-px x ex / (Lx / 2)
= Px × (1-2 × ex / Lx)
The above is the details of the correction in the X-axis direction. The correction in the Y-axis direction is the same as in the X-axis direction, and the defocus correction coefficient Ky is
Ky = ey / (Ly / 2 × h)
Indicated by Note that ey is a machining hole position error in the Y direction.

  As described above, the correction coefficient is obtained in advance from the processing hole position error at the outermost point A in the predetermined galvano scan area 410, and the command value of the processing position at the predetermined position in the galvano scan area is obtained using the correction coefficient. By correcting this, it is possible to prevent a processing position shift when performing defocus processing.

  In the above, the correction coefficient is obtained from the machining hole position error of only the point A. For example, the correction in the X-axis direction averages the machining hole position error of the points A and C, and the correction in the Y-axis direction is the point B, The correction coefficient may be obtained by averaging the machining hole position errors of D. Alternatively, the correction coefficient may be obtained by load-averaging the machining hole position errors at the five points A, B, C, D, and G. In these cases, the accuracy of position correction is further improved.

<Processing example 1>
FIG. 6A illustrates a processing example of the laser processing apparatus according to the embodiment of the present invention. The flowchart corresponding to FIG. 4 and the processing state of the workpiece are simply shown.

A defocus amount h is set between the front surface and the back surface of the workpiece 601 and a defocus correction coefficient is obtained in advance by actual processing (S50, S51). The machining position is analyzed with respect to the surface of the workpiece 601, a defocus correction value is calculated and the machining position is corrected, a galvano operation command is output, and laser light 602 is irradiated to make a hole in the surface. Perform (S52, S53, S54). Next, the front surface and the back surface of the workpiece are reversed. After the reversal, the machining position P is analyzed again, the machining position is corrected, a galvano operation command is output, and laser light 603 is irradiated to drill the back surface of the workpiece (S52, S53, S54).

  As described above, when the machining position correction is performed, the machining hole position from the front surface matches the machining hole position from the back surface, and thus the machining hole 604 is in a penetrating state. On the other hand, as shown in FIG. 6B, when the machining position correction is not performed, a deviation occurs between the machining hole position from the front surface and the machining hole position from the back surface, and the machining hole does not penetrate.

<Processing example 2>
FIG. 7A illustrates another example of processing of the laser processing apparatus according to the embodiment of the present invention, and shows a flowchart corresponding to FIG. 4 and the processing state of the workpiece.

  A defocus amount h is set between the front surface and the back surface of the workpiece, and a defocus correction coefficient is obtained in advance by actual processing (S50, S51). The processing position is analyzed with respect to the surface of the workpiece 701 of the first layer, a defocus correction value is calculated to correct the processing position, a galvano operation command is output, and the laser beam 702 is irradiated. (S52, S53, S54).

Next, the workpiece is exchanged for the second layer. Similarly, with respect to the surface of the workpiece 703 of the second layer, the machining position P is analyzed, a defocus correction value is calculated to correct the machining position, a galvano operation command is output, and the laser beam 704 is emitted. Irradiate (S52, S53, S54)
Next, the workpiece is exchanged for the third layer. Similarly, the processing position P is analyzed with respect to the surface of the workpiece 705 of the third layer, a defocus correction value is calculated to correct the processing position, a galvano operation command is output, and the laser beam 706 is emitted. Irradiate (S52, S53, S54).

  Finally, the workpieces 701, 703, and 705 of each layer are overlaid and stacked.

  As described above, when the machining position correction is performed, the machining holes 707 are penetrated because the machining hole positions of the first layer, the second layer, and the third layer are matched. On the other hand, as shown in FIG. 7B, when the machining position correction is not performed, a deviation occurs in the machining hole position of each layer, and the machining hole does not penetrate.

  The laser processing apparatus according to the present invention can perform high-precision processing by correcting the processing hole position when processing is performed with defocus, and performs drilling processing on a substrate using a laser. This is useful in a laser processing apparatus or the like.

DESCRIPTION OF SYMBOLS 100 Laser processing apparatus 110 Laser oscillator 111 Laser beam 112 Galvano scanner 113 Condensing lens 114 Processing position 115 Workpiece 116 Processing table 120 Laser pulse output command signal 121 Galvano operation command signal 122 Condensing lens position command signal 123 Galvano controller 124 Galvano Mirror 125 Galvano mirror 200 Control device 211 Main software processing unit 212 Parameter storage unit 213 Processing data analysis unit 214 Laser pulse command unit 215 Defocus correction unit (XY direction)
216 Defocus setting part (Z direction)

Claims (4)

A laser oscillator for receiving a laser pulse output command signal and emitting laser light;
A galvano device that operates in response to the command position information and positions the laser beam at the processing position of the workpiece;
A control device for controlling at least the laser oscillator and the galvano device;
A defocus correction unit that corrects the command position information according to a defocus amount;
A laser processing apparatus comprising: At least one point on the outermost edge of a predetermined galvano scan area, a correction coefficient is obtained from an actual processing position deviation amount with respect to a predetermined defocus amount,
The laser processing apparatus according to claim 1, wherein the command position information is corrected using the correction coefficient. When the length in the X-axis direction of the galvano scan area is Lx, the length in the Y-axis direction is Ly, the defocus amount is h, and the processing position deviation amount with respect to the defocus amount is ex,
The correction coefficient Kx in the X-axis direction is expressed as Kx = ex / ((Lx / 2) × h)
The correction coefficient Ky in the Y-axis direction is expressed as Ky = ey / ((Ly / 2) × h).
The laser processing apparatus according to claim 2. Correction data for correcting a processing position deviation that occurs in accordance with the defocus amount is prepared in advance, and the command position information of the laser beam with respect to the desired defocus amount is corrected based on the correction data. When drilling by emitting laser light to the position,
A laser processing method comprising drilling a front surface of a workpiece, then inverting the workpiece and drilling the same position on the back surface of the workpiece.

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