JP3769942B2 - Laser processing method and apparatus, and circuit forming method and apparatus for non-conductive transparent substrate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laser processing method for removing material from a workpiece by laser irradiation and a device therefor, for example, for forming a circuit made of a conductive thin film on all surfaces of a non-conductive transparent substrate. The present invention relates to a laser processing method and apparatus that can be used and is particularly suitable for fine processing.
[0002]
[Prior art]
In recent years, particularly in semiconductor manufacturing technology, high-precision fine processing combining photolithography technology and etching processing has been widely adopted. For example, in JP-A-60-73414, a conductive film is sputtered on both surfaces of a quartz substrate, a photoresist applied thereon is exposed and developed, patterned, and etched using this as a mask. A method is described in which a substrate is processed into an arbitrary shape with high accuracy, and the conductive film is etched to form a desired circuit with high accuracy.
[0003]
Recently, laser processing that focuses laser light on a minute spot and removes the workpiece using the high energy density that is obtained, and performs surface processing such as etching and surface modification has been widely put into practical use. Has been. As one of the two-dimensional scanning methods of the laser beam on the surface of the workpiece, as shown in FIG. 8, the workpiece 1 is placed on the XY axis table 2 and sent in the XY direction while the laser is applied to the surface. There is an XY table type scanning system that irradiates light 3. In this case, laser light irradiation is performed by the controller 5 connected to the laser oscillator 4 and the XY axis table 2 in synchronization with the driving of the table. Furthermore, a method is known in which a workpiece is placed on a four-axis table and irradiated with laser light for three-dimensional processing.
[0004]
As another method for two-dimensionally scanning laser light, there is a galvanometer type scanning method that uses separate galvanometer type optical scanners in the XY directions. FIG. 9 shows a typical configuration of a laser processing apparatus having such a galvanometer type scanning optical system, and an X-axis and Y-axis drive galvanometer having a laser oscillator 6 and scanning mirrors 7 and 8, respectively. 9 and 10 and a condensing lens 11 composed of a so-called f-θ lens. The laser beam 12 from the laser oscillator 6 is reflected between the scanning mirrors 7 and 8, condensed by the condenser lens 11, and irradiated on the surface of the workpiece 13. The laser light drives both galvanometers 9 and 10 separately to scan in the X direction and / or Y direction on the surface of the workpiece. In addition, a polygon mirror type scanning method in which the X axis is scanned at high speed with a polygon mirror and the Y axis is also sent in synchronization with this is adopted in the laser printer.
[0005]
A method of forming circuits on both front and back surfaces of a non-conductive transparent substrate such as a quartz substrate using laser processing is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-115338. According to the publication, a conductive thin film is deposited on the front and back surfaces of a quartz substrate, and a laser beam or other electromagnetic wave is focused on an intermediate position between those surfaces to simultaneously melt the conductive thin films on both the front and back surfaces. By evaporating, the same circuit can be simultaneously formed on both the front and back surfaces of the vibrating gyroscope. Furthermore, the publication describes that a circuit having a gap between electrodes on the front surface and the back surface can be formed by shifting the focal position of the laser light to either the front or back surface.
[0006]
[Problems to be solved by the invention]
However, in the above-described conventional etching process using photolithography, in order to form a circuit on both sides or all sides of the substrate, it is necessary to apply and etch photoresist separately on each side. Therefore, there is a problem that the processing steps are complicated, man-hours are increased, and time is required.
[0007]
In particular, it is difficult to apply photoresist or pattern the side surface of a thin substrate such as a quartz crystal vibrating piece or the inner surface facing through a narrow gap, and in practice it is difficult to etch a circuit with high accuracy. Not easy. Furthermore, when a fine pattern of about several tens of μm is formed or when the inside of a narrow gap is etched, there is a problem that etching defects are likely to occur due to the viscosity of the developer.
[0008]
The circuit forming method by laser processing disclosed in Japanese Patent Laid-Open No. 7-115338 has an advantage that man-hours can be reduced and quality can be improved as compared with conventional etching processing using photolithography. However, completely different circuit patterns cannot be formed on the front and back surfaces of the quartz substrate. Even if only one surface is processed and the focus of the laser beam is focused on the processing surface, if the thickness of the substrate is thinner than the focal depth of the laser beam, the opposite surface is processed in the same manner. Further, in the case of irradiating the laser beam by tilting the resonator element in order to process the inner surfaces facing each other through a narrow gap, the method described in this publication similarly uses another laser beam on the extension line. There is a risk of melting or removing even the conductive thin film.
[0009]
In general, when the above-described XY table type scanning method is used in laser processing, the XY axis table has a problem that high-speed driving is difficult and responsiveness is low, and the entire apparatus becomes large. As illustrated in FIG. 10A, in order to process a certain region A on the surface of the workpiece 1, the laser processing traces 14 by one irradiation are partially overlapped while feeding the table in the X direction. Next, the laser beam is similarly irradiated while shifting the table in the Y direction and feeding it in the opposite direction in the X direction. However, the range in which the table can be driven by one reciprocating drive in the X direction is at most about the width of the laser mark in consideration of the overlapping state of the laser mark, and the processing time is considered if the spot diameter of the laser beam is about 10 to 20 μm. Becomes longer. On the other hand, if the spot diameter is increased, the processing area by one laser irradiation is increased, but the energy density of the laser is lowered and processing time is very long. In any case, the scanning by driving the conventional XY axis table has a low resolution, so that the processing accuracy is lowered.
[0010]
In particular, when the workpiece is a non-conductive transparent substrate such as a quartz substrate, there arises a problem that the back surface is unnecessarily processed. 10 (a) and 10 (b), in the machining area A, in order to control the position of the table with higher accuracy, acceleration that gradually increases the table feed speed in the vicinity of the start point and end point along the feed direction. An area 15 and a gradually decreasing deceleration area 16 are provided. Since the output of the laser beam is usually constant, if the laser output is set in accordance with the constant speed region 17 between them, the irradiation energy is excessive in the acceleration region 15 and the deceleration region 16 due to excessive laser light overlap. Thus, not only the upper conductive film 18 but also the lower conductive film 19 may be processed or damaged. In addition, it is practically difficult to finely adjust the laser output during the processing operation. In order to adjust the power of the laser beam while keeping the output of the laser oscillator constant, it is necessary to provide a separate attenuation optical system. Arise.
[0011]
Galvanometer-type scanning laser processing is simple and compact, and is advantageous in terms of processing speed, accuracy, operability, simplicity, etc. However, the use of two scanning mirrors requires adjustment of the optical system. Difficult, particularly unsuitable for microfabrication, and further, there is a problem that processing accuracy is low and processing time is long because high-accuracy scanning is difficult and response is low.
[0012]
Therefore, the present invention is for solving the above-mentioned conventional problems, and its object is to improve processing accuracy and processing speed in two-dimensional or three-dimensional laser processing. It is possible to provide a method and an apparatus particularly suitable for microfabrication.
[0013]
Another object of the present invention is to provide a laser processing method and apparatus capable of separately processing conductive thin films formed on both front and back surfaces of a nonconductive transparent substrate to form circuits having different patterns. .
[0014]
[Means for Solving the Problems]
  According to the present invention,In order to process a workpiece by laser light irradiation,The process of sending the workpiece in a specified direction and the laser beam output from the laser oscillator is reflectedAnd the reflection direction can be controlled in two orthogonal directions.By driving the galvanometer mirror and changing its reflection direction, it consists of a process of scanning the laser beam in a direction different from the feed direction of the workpiece,The output of the laser light is linked to the driving of the galvanometer mirror so that it is higher than the processing threshold when scanning the processing region of the workpiece and lower than the processing threshold when scanning other than the processing region. adjustA laser processing method is provided.
[0015]
  In this way, the laser beam is irradiated on the surface of the workpiece by one galvanometer mirror without being influenced by the feed speed of the workpiece.In two orthogonal directionsCompared with the conventional scanning optical system that drives the XY axis table and two galvanometers separately in the X and Y directions, the responsiveness and operability are significantly improved, and high-speed and high-accuracy scanning and positioning is possible. Is possible. Here, when the laser beam is scanned in a direction perpendicular to the feeding direction of the workpiece, the workpiece can be scanned and machined in the XY directions.Furthermore, by adjusting the output of the laser beam in association with the driving of the galvanometer mirror, for example, the displacement of the mirror, the driving voltage, the position of the beam spot, etc., the laser beam is scanned corresponding to the processing region while controlling the irradiation energy. Therefore, it is possible to process a complex shape region and further improve the processing accuracy and processing speed.
[0016]
  Galvano mirrors, especially those that use the piezoelectric effect to change the direction of reflection, have higher resolution and better response than motor-driven ones, enabling more precise operation. So it is advantageous.
[0018]
The irradiated laser beam is preferably a pulsed laser beam having a low average output for a high peak output from the viewpoint of control of the irradiated energy, output, thermal influence, and the like. By adjusting the peak output, power density, pulse width, or number of irradiations of the laser beam, the energy of the laser beam can be controlled favorably in accordance with the processing region.
[0019]
Further, by further including a process of displacing the workpiece in a direction perpendicular to the feed direction of the workpiece and the scanning direction of the laser beam, three-dimensional processing becomes possible, particularly facing through a narrow gap in the substrate. This is advantageous when the inner surface is processed with the substrate inclined.
[0020]
  According to another aspect of the present invention, a processing table for placing a workpiece and sending it in a predetermined direction, a laser oscillator, and a surface of the workpiece by condensing laser light output from the laser oscillator The condenser lens for irradiating the laser beam and the laser beam from the laser oscillator is reflectedAnd the reflection direction can be controlled in two orthogonal directions.Galvano mirroras well asDriving device for driving the galvanometer mirror and changing its reflection directionFromAnd a scanning optical system for scanning the laser beam irradiated on the workpiece surface in a direction different from the feeding direction of the workpieceThe output of the laser light is linked to the driving of the galvanometer mirror so that it is higher than the processing threshold when scanning the processing area of the workpiece and lower than the processing threshold when scanning other than the processing area. Control device to adjustIs provided.
[0021]
  Combination of such a processing table and one galvanometer mirrorIn addition to synchronizing laser beam scanning and irradiation energy controlAccording to the present invention described above,ThanHigh-speed and high-precision laser processingeasilyAs well as being realized, the configuration of the entire apparatus is simplified and the size can be reduced.
[0023]
Furthermore, if the processing table can be displaced in a direction perpendicular to the workpiece feed direction and the laser beam scanning direction, three-dimensional laser processing is facilitated.
[0024]
  Further, according to the present invention, when the non-conductive substrate is transmitted through and condensed on a non-conductive substrate formed on the surface of the non-conductive substrate that is transparent to light of a predetermined wavelength, the conductive thin film In the method of forming a circuit by partially removing the conductive thin film by irradiating light of a specific wavelength capable of melting or evaporating the substrate, a process of sending the non-conductive substrate in a predetermined direction, and a light source Reflecting the lightAnd the reflection direction can be controlled in two orthogonal directions.By driving the galvanometer mirror and changing its reflection direction, the process of scanning the light in a direction different from the feeding direction of the non-conductive substrate, and the intensity of the light in association with the driving of the galvanometer mirrorWhen scanning the processing region of the conductive thin film, it is higher than the processing threshold, and when scanning other than the processing region, it is set lower than the processing threshold.A circuit forming method for a non-conductive transparent substrate is provided.
[0025]
By combining the operation of feeding the non-conductive substrate and the scanning of the laser beam by driving one galvanometer mirror in this way, scanning and positioning can be performed at higher speed and higher accuracy than conventional laser processing. By combining the adjustment of the intensity of irradiated light and the drive control of the galvanometer mirror, the processing region and the processing region of the conductive thin film can be distinguished and processed with higher accuracy, and the processing speed can be increased.
[0026]
At this time, the irradiation light is focused on the conductive thin film on the surface of the non-conductive substrate and the irradiation energy is set appropriately so that only the conductive thin film on the front surface is selectively selected and the conductivity on the back surface is selected. Since processing can be performed without affecting the thin film, separate circuit patterns can be formed on the front and back surfaces.
[0027]
In one embodiment, when the non-conductive substrate has inner surfaces facing each other with a certain gap, the substrate is inclined and the light is incident on one inner surface through the gap. By focusing the light on the conductive thin film on one inner surface, only the desired inner surface is processed without affecting the other conductive thin film on the extension line of the incident light. Therefore, a circuit can be formed on all surfaces of such a substrate.
[0028]
The light is advantageously laser light with excellent directivity and light condensing properties, and it is more convenient to use pulsed laser light from the viewpoints of irradiation energy control, high output, thermal influence, and the like.
[0029]
Further, in the case of a pulsed laser, the magnitude of the laser energy to be irradiated depends on the magnitude of the standby time of the pulse, so that the laser energy by the first pulse is greater than a predetermined value, so that the non-conductive substrate When the scanning of the laser beam is started from the outside position, the excessively oscillated laser energy that is first oscillated is not applied to the non-conductive substrate, so that there is no possibility of damaging the substrate or processing unnecessary parts. . In another embodiment, the laser light oscillated by the first pulse is selectively cut off by using an appropriate mechanical or optical shutter means known in the art, and then scanning of the laser light is started. The adverse effect of the excessive laser energy can be prevented.
[0030]
  Further, according to another aspect of the present invention, in an apparatus for forming a circuit by partially removing a conductive thin film formed on a surface of a nonconductive substrate that is transparent to light of a predetermined wavelength, A processing table for sending a conductive substrate in a predetermined direction, a light source that transmits light through the non-conductive substrate and generates light of a specific wavelength that can melt or evaporate the conductive thin film when condensed, and the light source Reflecting light fromAnd the reflection direction can be controlled in two orthogonal directions.An optical system that includes a galvanometer mirror and a driving device that drives the galvanometer mirror to change its reflection direction, condenses the light on a conductive thin film, and scans in a direction different from the feeding direction of the non-conductive substrate. System and the light intensity from the light source linked to the light scanningWhen scanning the processing region of the conductive thin film, it is higher than the processing threshold, and when scanning other than the processing region, it is set lower than the processing threshold.There is provided a circuit forming apparatus for a non-conductive transparent substrate, comprising a control device for adjusting.
[0031]
In one embodiment, a laser oscillator that outputs laser light to the light source can be used.
[0032]
In another embodiment, a three-dimensional processing can be performed by using a processing table that is displaceable in a direction perpendicular to the feeding direction of the non-conductive transparent substrate and the scanning direction of the laser beam.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail by way of examples with reference to the accompanying drawings.
FIG. 1 schematically shows the configuration of a preferred embodiment of a laser processing apparatus according to the present invention. The laser processing apparatus of the present embodiment includes a laser oscillator 21 that outputs laser light, a condensing lens 22 that irradiates the laser beam toward a workpiece, and a laser beam from the laser oscillator 21 that is directed toward the condensing lens 22. And a galvanometer mirror 23 that reflects and a processing table 24 on which a workpiece is placed and which can be moved in three axial directions X, Y, and Z.
[0034]
The galvanometer mirror 23 includes a piezo-type galvanometer 25 having a platform that can be tilted with high precision control in two axial directions, and a scanning mirror 26 attached to the platform. As such a galvanometer, a type in which a platform is driven using a plurality of piezoelectric transducers is commercially available from, for example, Physik Instrumente (PI) GmbH & Co. of Germany.
[0035]
In this embodiment, a quartz substrate 27 is placed on a processing table 24 as a workpiece, and conductive thin films 28 and 29 such as chromium and gold formed on the front and back surfaces are removed separately or simultaneously. The crystal substrate 27 can be placed on the processing table 24 using an appropriate jig as required.
[0036]
FIG. 2 shows a configuration of a control system for the entire laser processing apparatus. The galvanometer mirror 23 is connected to a control device 30 for controlling the tilt of the galvanometer 25. The control device 30 is connected to the laser oscillator 21 and the condenser lens 22. The movement of the machining table 24 is controlled by the table driver 31. The control device 30 and the table driver 31 operate according to a command from the common computer 32.
[0037]
The computer 32 causes the laser beam B to be output from the laser oscillator via the control device 30. The laser beam B is reflected by the scanning mirror 26, condensed by the condenser lens 22, and irradiated on the surface of the crystal substrate 27. Similarly, the computer 32 adjusts the condensing lens 22 via the control device 30 to adjust the focal position of the laser light to the surface of the quartz substrate.
[0038]
The reflection direction of the scanning mirror 26 can be continuously changed by changing the tilt angle of the platform by an input signal from the control device 30 instructed by the computer 32. By synchronizing the oscillation of the laser beam with the driving of the scanning mirror and adjusting the irradiation energy, the processing region on the surface of the quartz substrate can be distinguished from the processing region, and processing can be performed with high accuracy and at high speed. Further, the computer 32 sends a signal to the table driver 31 in synchronization with the scanning of the laser beam to move the processing table 24.
[0039]
Further, three-dimensional machining is possible by further moving the machining table 24 in the Z-axis direction. At this time, by placing the quartz crystal substrate obliquely on the processing table 24 using an appropriate jig, which will be described later, the inner surface of the substrate can be directly irradiated with laser light for processing.
[0040]
Next, the process of removing the conductive thin film of the quartz substrate 27 by the laser processing apparatus of FIGS. 1 and 2 will be described with reference to FIG. As shown in FIGS. 3A and 3B, the conductive thin film 28 on the upper surface of the substrate has a processing region 33 for laser processing at the center along the feed direction of the processing table 24, that is, the Y direction orthogonal to the X direction. The left and right ends are divided into non-processed areas 34 and 35 that are not laser processed.
[0041]
In this embodiment, a Q-switch pulse oscillation YAG laser having a short pulse width and little thermal influence is used. The laser beam scans by linearly reciprocating between the processing start position P1 and the processing end position P2 provided on the left and right outer sides of the quartz substrate 27. Simultaneously with the scanning of the laser beam in the Y direction, the processing table 24 is moved in the X (+) direction. The laser beam irradiation is performed in synchronization with the operation of the scanning mirror 26 that changes the scanning direction of the laser beam, that is, the reflection direction, so that the beam spots of the laser beams on the surface of the conductive thin film 28 are partially overlapped and continued. .
[0042]
The laser scanning speed is controlled so that a constant speed is maintained in the processing region 33, and adjacent beam spots are continuously overlapped at a constant rate as round processing marks 36, and no unirradiated portion remains. The non-machining areas 34 and 35 include an acceleration area from the machining start position P1 and a deceleration area to the machining end position P2. In these acceleration / deceleration areas, the laser scanning speed is lower than the machining area 33. The beam spots 37, 38 overlap at a larger rate.
[0043]
The computer 32 creates data necessary for etching the quartz substrate and supplies it to the control device 30. As shown in FIGS. 3 (c) and 3 (d), the control device 30 outputs laser oscillation signals S 1, S 2, S 3 having different pulse widths to the laser oscillator 21 based on the operation position based on this data. The laser oscillator 21 pulse-oscillates laser beams having peak outputs having different sizes corresponding to the input laser oscillation signal (for example, pulse interval).
[0044]
In the processing region 33, the peak value of the pulse p2 is higher than the processing threshold value Q0 on the upper surface of the substrate and lower than the processing threshold value Q1 on the lower surface of the substrate, and only the upper conductive film 28 is melted without affecting the lower conductive film 29.・ For example, the oscillation frequency is set to 10 kHz so that it can be removed. The oscillation frequency in the non-processed regions 34 and 35 is set to, for example, 40 kHz so that the peak values of the pulses p1 and p3 are sufficiently lower than the processing threshold value Q0 and are not affected even when the overlap of the beam spots is increased. To do.
[0045]
First, the galvano mirror 23 is driven so that the irradiation position of the laser beam is aligned with the processing start position P1, and laser oscillation and scanning are started in the + Y direction at a frequency of 40 kHz by the laser oscillation signal S1. At this time, the peak value of the first oscillation pulse p11 is remarkably large because the standby time is long. However, since the laser beam with an excessive output is irradiated at a position outside the quartz substrate 27, the substrate is not affected at all. In another embodiment, by using a conventionally known mechanical or optical shutter or the like to cut off the laser beam generated by the first oscillation pulse, the laser beam having an excessively large output can be similarly applied to the substrate. Can be prevented.
[0046]
When the laser beam reaches the boundary position P3 between the non-processed region 34 and the processed region 33, the laser output is switched to a laser oscillation signal S2 having a frequency of 10 kHz, the laser output is changed to a processable level, and scanning of the laser beam is continued. Next, when the laser beam reaches the boundary position P4 between the machining area 33 and the non-machining area 35, the laser oscillation signal S3 having a frequency of 40 kHz is switched to return the laser output to a level at which machining is impossible.
[0047]
When the laser beam reaches the processing end position P2, the laser beam is scanned in the opposite direction, that is, in the −Y direction, with the start point as the start point and the position P1 as the end point. Switching of the oscillation frequency and the laser output at the boundary positions P4 and P3 between the non-processed areas 34 and 35 and the processed area 33 is performed in the same manner as the scanning in the + Y direction described above. Then, while feeding the processing table 24 in the X direction, these series of operations are repeated until the rear end of the processing region 33 in the X direction is reached, and the entire processing region 33 on the upper surface is moved without damaging the conductive thin film 29 on the lower surface. Etch.
[0048]
The feed rate of the processing table 24 is set so that the processing marks 36 by the laser overlap sufficiently to the extent that the lower surface of the substrate is not damaged in the X direction. The scanning speed of the galvanometer mirror 23 can be set at a very high speed compared with the feed speed of the processing table 24. Therefore, the processing speed of the quartz substrate 27 depends on the feed speed of the processing table 24 apart from the processing threshold value depending on the material and film thickness of the conductive thin film itself to be removed.
[0049]
For example, assuming that the spot diameter of the laser beam is 90 μm and the overlapping ratio of the beam spots is 50%, it is necessary to reciprocate the processing table about 30 times in order to process an area having a width of only 1 mm by moving the processing table. is there. On the other hand, in the present invention, the machining is completed only by sending the machining table once in one direction in the X direction. That is, according to the present invention, even if only the feed rate of the machining table 24 is taken into account, the machining time is reduced to 1/60 of the prior art. Further, if the scanning speed of the galvanometer mirror 23 is taken into consideration, the processing time can be further shortened in practice.
[0050]
In another embodiment, the laser light is scanned in the Y direction and the timing for switching the oscillation frequency is changed while the laser light is scanned in the Y direction, so that a region or a plurality of regions having different positions or lengths in the Y direction can be obtained. Can be processed. Furthermore, by changing the timing for switching the oscillation frequency along the X direction, not only a rectangular region having a constant width as in the above embodiment but also a region having a complicated shape can be processed.
[0051]
In still another embodiment, the laser beam can be scanned obliquely with respect to the X direction in which the processing table is sent. In this case as well, the scanning of the laser beam can be performed simultaneously with the processing table or separately. In particular, by using the galvanometer mirror capable of two-axis control described above and performing scanning while switching obliquely and in the Y direction, more complicated processing can be performed with high accuracy.
[0052]
Next, a description will be given of a case where circuits are formed on the front and back surfaces and other surfaces of the vibration gyro which is extracted by converting acceleration into an electric signal by using the laser processing of the present invention. FIG. 4 shows a configuration of a general vibrating gyroscope 40, which includes a pair of vibrating pieces 42, 43, 44, 45 that protrude from the base 41 on both sides. A circuit for converting strain energy into electric energy when an external force is applied is formed on the entire surface of the vibration gyro.
[0053]
The vibration gyro is first etched from a quartz substrate having a piezoelectric effect into the shape shown in FIG. 4, for example, the overall dimensions are 3.5 mm × 16 mm × 0.5 mm (X × Y × Z), and the dimensions of the vibration pieces 42 and 43. Is formed to 0.25 mm × 6 mm × 0.5 mm (X × Y × Z), and a conductive thin film is attached to the entire surface by vapor deposition or the like. Next, the conductive thin film 46 is partially removed to form circuits with various patterns on all surfaces of the vibrating pieces.
[0054]
As an example, the front surface 47 and the rear surface 48 of the vibrating piece 42 are shown in FIGS. The conductive thin films in regions 49 and 50 (hatched portions) having different patterns corresponding to the circuits are removed from the front and back surfaces of the vibrating piece 42. The surface 47 is etched in a region 49 as shown in FIG. 6 using the laser processing apparatus shown in FIGS.
[0055]
For example, in a range where the back surface portion corresponding to the surface region 49 does not coincide with the region 50 to be etched, the focal position of the laser beam B is adjusted to the conductive thin film on the surface 47 as shown in FIG. At this time, the output of the laser beam is naturally set to a level at which the conductive thin film on the back surface 48 is not processed. On the other hand, as shown in FIG. 6B, the portion where the areas to be etched on the front surface 47 and the rear surface 48 coincide with each other was scanned again with laser light along the same path to remove the conductive thin film. By irradiating the laser beam B through the gap of the region 49, the conductive thin film on the back surface 48 is removed. At this time, the focal position of the laser beam B is adjusted to the rear surface 48 by adjusting the position of the condenser lens 22 that can be displaced up and down, and the output is a level at which the conductive thin film not processed on the front surface 47 is processed. Set to.
[0056]
The portion of the region 50 on the back surface 48 that has not been processed simultaneously with the front surface is processed by direct irradiation with laser light as follows. As shown in FIG. 7, using a suitable jig 51 fixed on the processing table 24, the laser beam B directly irradiates the back surface 48 of the vibrating piece 42 through the narrow gap 52 between the vibrating pieces 42 and 43. The gyro 40 is installed at an angle as possible. The laser beam drives the galvanometer mirror 23 to scan in the X direction in the figure. The output of the laser beam is adjusted to a level that does not affect the conductive thin film on the surface 47 at all.
[0057]
When it is necessary to process in the direction of the arrow C in the figure in the width direction of the vibrating piece 42, the laser beam B is scanned in the X direction by the galvano mirror 23 while moving the processing table 24 in the Y direction. The focus of the laser beam is set so that the height of the condenser lens 22 is changed in accordance with the change in the height of the processing site, and is always on the conductive thin film on the back surface 48. This control is performed by the computer 32 in association with the movement of the machining table 24 via the control device 30 and the table driver 31. In another embodiment, the processing table 24 may be fixed and the laser beam B may be scanned and processed in the X direction and the Y direction.
[0058]
In this way, only the conductive thin film on the back surface 48 of the vibrating piece 42 can be etched without affecting the conductive thin film on the surface 47 on the opposite side. By processing the other vibrating pieces 43 to 45 in the same manner, a circuit having a desired pattern can be formed on the entire surface of the gyro.
[0059]
As mentioned above, although this invention was demonstrated in detail using the suitable Example, this invention is not limited to the said Example, It can implement by adding various deformation | transformation and change within the technical scope. it can. For example, in the above-described embodiment, the galvano mirror 23 that can be controlled in two axes is used. The effect of this can be obtained.
[0060]
1 uses a scanning optical system in which a polarizing beam splitter and a λ / 4 plate are arranged between a condenser lens 22 and a galvanometer mirror 23, and the laser processing apparatus from a laser oscillator arranged outside the optical path. The laser beam passes through the polarizing beam splitter and the λ / 4 plate, is reflected by the galvanometer mirror, passes again through the λ / 4 plate and the polarizing beam splitter, and is collected by the condenser lens 14 and irradiated to the non-workpiece 27. It can be constituted as follows. In this case, a more linear laser beam can be scanned and the accuracy is improved.
[0061]
【The invention's effect】
Since this invention is comprised as mentioned above, there exists an effect as described below.
According to the laser processing method of the present invention, the laser light can be scanned by one galvanometer mirror without being influenced by the feed speed of the workpiece, so that the processing accuracy and processing speed are greatly improved, and fine processing is performed. 2D or 3D laser processing can be realized for various materials including a quartz substrate.
[0062]
Further, according to the circuit forming method of the non-conductive transparent substrate of the present invention, the quartz substrate is adjusted by scanning the laser beam by driving one galvanometer mirror and adjusting the intensity of the irradiated light in association with the scanning. Even if it is a thin non-conductive transparent substrate, such as the front and back, and by tilting the substrate relative to each other, a different circuit pattern is applied to each other without affecting or damaging the other surface. It can be formed with high accuracy and at high speed.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of a laser processing apparatus according to the present invention.
2 is a block diagram showing a configuration of a control system for the entire apparatus of FIG. 1;
3A is a plan view for explaining a process of forming a circuit on the surface of a non-conductive transparent substrate using the apparatus of FIG. 1, FIG. 3B is a cross-sectional view thereof, and FIG. FIGS. 4A and 4D are diagrams respectively showing a laser oscillation signal and an oscillation pulse for oscillating a laser beam along the transverse direction of the substrate.
FIG. 4 is a perspective view showing a vibrating gyroscope that forms a circuit by applying the present invention.
FIGS. 5A and 5B are side views showing different circuits of the gyro arm, respectively.
FIGS. 6A and 6B are explanatory views showing a process of laser processing the front surface and the back surface of the vibrating gyroscope, respectively.
FIG. 7 is an explanatory view showing a process of laser processing the inner surface of the gyro arm.
FIG. 8 is a schematic view showing a configuration of a laser processing apparatus provided with a conventional processing table.
FIG. 9 is a schematic view showing a configuration of a laser processing apparatus including a conventional galvanometer type scanning optical system.
10A is a plan view of the surface of a non-conductive transparent substrate processed by the conventional method of FIG. 8, and FIG. 10B is a longitudinal sectional view thereof.
[Explanation of symbols]
1 Workpiece
2 XY axis table
3 Laser light
4 Laser oscillator
5 Controller
6 Laser oscillator
7, 8 Scanning mirror
9, 10 Galvanometer
11 Condensing lens
12 Laser light
13 Workpiece
14 Laser processing marks
15 Acceleration range
16 Deceleration range
17 Constant speed range
18, 19 Conductive film
21 Laser oscillator
22 Condensing lens
23 Galvano mirror
24 Processing table
25 Galvanometer
26 Scanning mirror
27 Quartz substrate
28, 29 Conductive thin film
30 Control device
31 Table driver
32 computers
33 Processing area
34, 35 Non-working area
36 processing marks
37, 38 Beam spot
40 Vibrating gyro
41 Base
42 to 45 Vibrating piece
46 Conductive thin film
47 Surface
48 Back side
49, 50 area
51 Jig
52 gap

Claims (21)

In a laser processing method of processing a workpiece by laser light irradiation,
Sending the workpiece in a predetermined direction;
By driving a galvanometer mirror that reflects the laser beam output from the laser oscillator and can control the reflection direction in two orthogonal directions , the reflection direction is changed, thereby different from the feeding direction of the workpiece. Scanning the laser beam in the direction ,
The output of the laser light is linked to the driving of the galvanometer mirror so that it is higher than the processing threshold when scanning the processing region of the workpiece and lower than the processing threshold when scanning other than the processing region. The laser processing method characterized by adjusting .   The laser processing method according to claim 1, wherein the galvanometer mirror is a piezo galvanometer mirror that changes a reflection direction using a piezoelectric effect.   The laser processing method according to claim 1, wherein the laser beam is scanned in a direction orthogonal to a feeding direction of the workpiece. Laser processing method according to any one of claims 1 to 3, further comprising the step of displacing the workpiece in the vertical direction with respect to the scanning direction of the feeding direction and the laser beam of the workpiece. Laser processing method according to any one of claims 1 to 4, characterized by using a pulsed laser light. A processing table for loading a workpiece and feeding it in a predetermined direction;
A laser oscillator;
A condensing lens for condensing the laser beam output from the laser oscillator and irradiating the workpiece surface;
It consists driving device for changing the controllable galvanomirror laser beam in two axial directions that reflects vital perpendicular to the reflection direction, and the reflected direction by driving the galvanometer mirror from the laser oscillator, the object A scanning optical system that scans laser light applied to the surface of the workpiece in a direction different from the feeding direction of the workpiece ;
The output of the laser light is linked to the driving of the galvanometer mirror so that it is higher than the processing threshold when scanning the processing region of the workpiece and lower than the processing threshold when scanning other than the processing region. A laser processing apparatus comprising a control device for adjustment . The laser processing apparatus according to claim 6 , wherein the galvanometer mirror is a piezo-type galvanometer mirror capable of changing a reflection direction using a piezoelectric effect. The laser processing apparatus according to claim 6 , wherein the scanning optical system is capable of scanning the laser beam in a direction orthogonal to a feeding direction of the workpiece. 9. The laser processing apparatus according to claim 6, wherein the processing table is displaceable in a direction perpendicular to a workpiece feed direction and a laser beam scanning direction. A specific wavelength capable of melting or evaporating the conductive thin film when the non-conductive substrate is transmitted through and condensed on a conductive thin film formed on the surface of the non-conductive substrate that is transparent to light of a predetermined wavelength. In the method of forming a circuit by partially removing the conductive thin film by irradiating
Sending the non-conductive substrate in a predetermined direction;
By driving a galvanometer mirror that reflects the light from the light source and that can be controlled in a biaxial direction orthogonal to the reflection direction, the reflection direction is changed, so that the light is sent to the feeding direction of the non-conductive substrate. Scanning in different directions;
The light intensity is linked to the driving of the galvanometer mirror so that it is higher than the processing threshold when scanning the processing region of the conductive thin film and lower than the processing threshold when scanning other than the processing region. A circuit forming method for a non-conductive transparent substrate comprising the steps of:   The circuit forming method according to claim 10, wherein the light is scanned in a direction orthogonal to a feeding direction of the non-conductive substrate. The light is focused on the conductive thin film on the surface of the non-conductive substrate, and the irradiation energy is appropriately set so as not to affect the conductive thin film on the back surface of the non-conductive substrate. The circuit forming method according to claim 10 or 11 . The non-conductive substrate has inner surfaces facing each other with a certain gap in between, and the non-conductive substrate is inclined so that the light is incident on one of the inner surfaces through the gap. The circuit forming method according to claim 10 , wherein the light is condensed on the conductive thin film on the one inner surface. The circuit forming method according to claim 10 , wherein the light is a laser beam. 15. The circuit forming method according to claim 14 , wherein pulsed laser light is used. 16. The circuit forming method according to claim 15 , wherein scanning of the laser beam is started from a position outside the nonconductive substrate as a starting point. 17. The circuit forming method according to claim 16 , wherein scanning of the laser beam is started after selectively blocking the laser beam oscillated by the first pulse. In an apparatus for forming a circuit by partially removing a conductive thin film formed on the surface of a non-conductive substrate that is transparent to light of a predetermined wavelength,
A processing table for sending the non-conductive substrate in a predetermined direction;
A light source that transmits the non-conductive substrate and generates light of a specific wavelength that can melt or evaporate the conductive thin film when condensed;
A galvanometer mirror that reflects light from the light source and that can be controlled in a biaxial direction orthogonal to the reflection direction; and a driving device that drives the galvanometer mirror to change the reflection direction. An optical system that focuses light on the conductive thin film and scans in a direction different from the feeding direction of the non-conductive substrate;
The intensity of the light from the light source is linked to the driving of the galvanometer mirror, and is higher than a processing threshold when scanning the processing region of the conductive thin film, and lower than the processing threshold when scanning other than the processing region. A circuit forming apparatus for a non-conductive transparent substrate, comprising: The laser processing apparatus according to claim 18 , wherein the optical system is capable of scanning the light in a direction orthogonal to a feeding direction of the non-conductive substrate. The circuit forming apparatus according to claim 18, wherein the light source is a laser oscillator that outputs laser light. 21. The circuit forming apparatus according to claim 18, wherein the processing table is displaceable in a direction perpendicular to a feeding direction of the non-conductive transparent substrate and a scanning direction of the laser beam.

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