JP5504503B2 - Pattern generation method, pattern generation apparatus, and laser processing apparatus - Google Patents

Description

  The present invention relates to a method of generating a predetermined pattern by individually tilting a plurality of micromirrors of a micromirror device, and more specifically, continuously generating the same pattern by repeatedly emitting light at least twice. In particular, the present invention relates to a pattern generation method, a pattern generation apparatus, and a laser processing apparatus that attempt to stabilize the generation of patterns.

  In this conventional pattern generation method, a laser oscillator that generates laser light irradiates a micromirror device in which a plurality of micromirrors are arranged in a matrix, and corresponds to the processing pattern of the workpiece. Each micromirror is tilted individually, and the cross-sectional shape of the laser light reflected by the micromirror is converted into modulated light having a shape corresponding to the processing pattern (see, for example, Patent Document 1).

  In this case, generally, as shown in FIG. 3, a storage element 13 such as a CMOS transistor for storing tilt information of each micromirror 12 is provided on the back side of each micromirror 12 of the micromirror device 10. .

JP 2006-350123 A

  However, in such a conventional pattern generation method, when the micromirror 12 is tilted to generate a predetermined pattern, as shown in FIG. In some cases, the storage element 13 is penetrated into the storage element 13 to irradiate the storage element 13, and a photocurrent is generated to erase the tilt information of the micromirror 12 stored in the storage element 13. Therefore, when the laser beam is repeatedly irradiated at least twice to process a pattern with a predetermined shape at a predetermined depth, the tilt information of the micromirror 12 stored in the storage element 13 is lost due to the generation of the photocurrent. As a result, the tilted state of the micromirror 12 cannot be maintained. Therefore, the predetermined pattern cannot be laser processed at a predetermined depth.

  Therefore, the present invention addresses such problems, and a pattern that stabilizes pattern generation even when light is repeatedly emitted at least twice and the same pattern is continuously generated. An object of the present invention is to provide a generation method, a pattern generation apparatus, and a laser processing apparatus.

In order to achieve the above object, a pattern generation method according to a first invention has a plurality of micromirrors that are individually tilted based on transferred pattern information and arranged in a matrix, and the back surface of each micromirror. Light is emitted from a light source to a micromirror device provided with a storage element for storing tilt information of each micromirror corresponding to the pattern information corresponding to each side, and light is irradiated by reflected light from the micromirror device A pattern generation method for generating a predetermined pattern on an object, wherein when the same pattern is continuously generated by repeatedly emitting light from the light source to the micromirror device at least twice or more repeatedly Until the number of times the light is emitted reaches a predetermined number of times, one shot of light is emitted from the light source. After, the until emission of the next shot of light is performed by the leakage light of the light entering from the gap of the micromirrors adjacent said tilt information is lost to the memory element stores, the Pattern information identical to the pattern information transferred immediately before the micro mirror starts to rotate is transferred to the micro mirror device at the timing before the micro mirror starts to rotate by the elastic restoring force of the shaft supporting the micro mirror.

With such a configuration, when the same pattern is continuously generated by intermittently emitting light from a light source at least twice or more to a micromirror device having a plurality of micromirrors arranged in a matrix, Until the number of times of light emission reaches a predetermined number of times set in advance, after one shot of light is emitted from the light source, until the next one shot of light is emitted , the adjacent micromirrors The tilt information stored in the storage element is lost due to the light leakage of the light that has entered from the gap, and the micromirror starts rotating due to the elastic restoring force of the shaft that supports the micromirror. Memory provided corresponding to the back side of each micromirror by transferring the same pattern information as the pattern information transferred immediately before to the micromirror device The tilt information of each micromirror corresponding to the pattern information is stored in the child, and a plurality of micromirrors are individually tilted based on the tilt information, and the light is reflected on the object to be irradiated by the reflected light from the micromirror device. Generate a pattern.

According to a second aspect of the present invention, there is provided a pattern generating apparatus comprising: a light source that intermittently emits light; and a storage element provided corresponding to each of the back surfaces of a plurality of micromirrors arranged in a matrix. A micromirror device that stores tilt information, tilts each micromirror individually based on the tilt information, reflects light incident from the light source, and generates a predetermined pattern on a light irradiation target; Control means for transferring pattern information corresponding to the tilt information to the micromirror device and storing the tilt information in the storage element, the control means comprising the micromirror device When the same pattern is continuously generated by repeatedly emitting light from the light source intermittently at least twice or more, the light emission Until a few reaches a predetermined number of times set in advance, after one shot of light emitted from the light source, the until emission of the next shot of light takes place, from the gap of the micromirrors adjacent The tilt information stored in the storage element disappears due to the leaked light of the light that has entered, and immediately before the micromirror starts to rotate due to the elastic restoring force of the shaft that supports the micromirror. The same pattern information as the transferred pattern information is transferred, and the tilt information is stored in the storage element.

With such a configuration, when a micromirror device having a plurality of micromirrors arranged in a matrix form is continuously radiated light from a light source at least twice or more repeatedly to continuously generate the same pattern, until it reaches a predetermined number of times the radiation preset times of light control means, after one shot of light emitted from the light source, the until emission of the next shot of light takes place, adjacent the Before the micromirror starts to rotate due to the elastic restoring force of the shaft that supports the micromirror, due to the leakage light of the light that has entered through the gap between the micromirrors, the tilt information stored in the storage element is lost. corresponding respectively to transfer the same pattern information and transferred pattern information immediately before the micro mirror device on the back side of each of the micromirrors in the timing The tilt information of each micromirror corresponding to the pattern information is stored in the storage element provided, the plurality of micromirrors are tilted individually based on the tilt information, and the light irradiation object is reflected by the reflected light in the micromirror device. A predetermined pattern is generated on the top.

  Furthermore, the light source emits one shot of light at a timing when a response signal indicating that the transfer of the pattern information is correctly performed is returned from the micromirror device to the control unit. Thus, one shot of light is emitted from the light source at the timing when the response signal indicating that the pattern information has been correctly transferred is returned from the micromirror device to the control means.

  Furthermore, the light source is a laser light source that emits a high-energy laser beam capable of processing the object to be irradiated with the light. As a result, a high-energy laser beam is emitted from the laser light source to process the light irradiation target.

  And the said light source radiates | emits the ultraviolet-ray which makes photosensitive resin apply | coated to the said irradiation object of light. Thereby, the photosensitive resin applied to the object to be irradiated with light is emitted by radiating ultraviolet rays from the light source.

According to a third aspect of the present invention, there is provided a laser processing apparatus comprising: a laser light source that intermittently emits laser light; and a storage element provided corresponding to each of the back surfaces of a plurality of micromirrors arranged in a matrix. A micro that stores tilt information of a mirror, tilts each micro mirror individually based on the tilt information, reflects a laser beam incident from the laser light source, and generates a predetermined pattern on a light irradiation object. A mirror device, and control means for transferring pattern information corresponding to the tilt information to the micromirror device and storing the tilt information in the storage element, and on the light irradiation object side of the micromirror device. A laser processing apparatus for laser processing the object to be irradiated with reflected laser light, wherein the control means includes the micromirror device. When the same pattern is continuously generated by repeatedly emitting laser light from the laser light source intermittently at least twice, until the number of times the laser light is emitted reaches a preset number of times. The leakage light of the light that has entered from the gap between the adjacent micromirrors until the next one shot of laser light is emitted after the one shot of laser light is emitted from the laser light source , The same pattern information transferred immediately before the micro mirror starts rotating due to the elastic restoring force of the shaft supporting the micro mirror when the tilt information stored in the storage element disappears Information is transferred and the tilt information is stored in the storage element.

With such a configuration, when a micromirror device having a plurality of micromirrors arranged in a matrix is repeatedly irradiated with laser light from a laser light source at least twice or more to continuously generate the same pattern. In addition, until the number of times the laser light is emitted by the control unit reaches a predetermined number of times set in advance, after one shot of laser light is emitted from the laser light source, the next one shot of laser light is emitted. The tilt information stored in the storage element disappears due to the light leakage light that has entered through the gap between the adjacent micromirrors, and the micromirror is caused by the elastic restoring force of the shaft that supports the micromirror. the same pattern information and the pattern information transferred immediately before the previous timing of starting the rotation is transferred to the micro-mirror device The tilt information of each micromirror corresponding to the pattern information is stored in the memory elements provided corresponding to the back surfaces of the plurality of micromirrors of the micromirror device, and each micromirror is individually stored based on the tilt information. It tilts, a predetermined pattern is generated on the light irradiation object by the reflected light from the micromirror device, and the light irradiation object is laser processed by this laser light.

According to the first or second aspect of the present invention, pattern generation can be stabilized even when the same pattern is continuously generated by repeatedly emitting light to the micromirror device a plurality of times.

Further, the invention according to claim 3, may be micro mirrors from the light source during tilting is prevented from being emitted. Therefore, the pattern generation by the micromirror device can be further stabilized.

Furthermore , according to the invention which concerns on Claim 4 , the laser irradiation object can be processed into the pattern shape produced | generated by the micromirror device.

Furthermore, according to the invention according to claim 5, it is possible to expose the photosensitive resin applied to the irradiation object light in a pattern shape that is generated by the micro mirror device.

In the invention according to claim 6, also in generating continuously the same pattern of laser light is a plurality of times repeatedly radiating the micromirror device, the laser machining accuracy by stabilizing the generation of the pattern Can be improved.

It is a front view which shows embodiment of the laser processing apparatus by this invention. It is a top view which shows the micromirror device of the pattern production | generation apparatus of this invention. In the said micromirror device, it is explanatory drawing which shows that a laser beam penetrate | invades from the clearance gap between adjacent micromirrors. It is explanatory drawing which shows the drive state of the micromirror of the said micromirror device, (a) shows an ON drive state, (b) has shown the OFF drive state. It is a flowchart shown about the pattern production | generation method of this invention. It is a timing chart explaining the pattern generation operation | movement in the pattern generation apparatus of this invention.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a front view showing an embodiment of a laser processing apparatus according to the present invention. This laser processing apparatus tilts a plurality of micromirrors of a micromirror device individually to generate a pattern corresponding to the processing pattern and performs laser processing. The stage 1, the pattern generation apparatus 2, the objective lens 3, The imaging lens 4, the imaging means 5, the illumination light source 6, and the displacement means 7.

  The stage 1 is configured to place a workpiece 8 as a light irradiation target on the upper surface and move it in the horizontal plane in the X-axis and Y-axis directions, and is configured by combining a motor, a gear, etc., not shown. It is moved by the driving means. The Y-axis direction is the depth direction in FIG.

  A pattern generation device 2 is provided above the stage 1. The pattern generation device 2 generates a predetermined pattern by individually tilting a plurality of micromirrors of a micromirror device, and includes a laser light source 9, a micromirror device 10, and a control unit 11. .

  Here, the laser light source 9 emits a laser beam L1, irradiates the workpiece 8, and processes the workpiece 8. For example, a pulse laser that emits a laser beam L1 having a wavelength of 532 nm or 355 nm. The control of the emission time of the laser light L1 is performed by the Q switch.

  A micromirror device 10 is provided in front of the laser light L1 emitted from the laser light source 9 in the emission direction. As shown in FIG. 2, the micromirror device 10 includes a plurality of micromirrors 12 arranged in a matrix. As shown in FIG. 3, the micromirror device 10 has a memory element corresponding to the back side of each micromirror 12. 13 is provided to store tilt information of each micromirror 12 in the storage element 13, and each micromirror 12 is tilted individually based on the tilt information, and the laser light L1 incident from the laser light source 9 is reflected. Thus, the cross-sectional shape of the laser beam L1 is shaped into a shape corresponding to the machining pattern, and a predetermined pattern is generated on the workpiece 8 by the shaped laser beam L1.

  In FIG. 3, reference numeral 14 denotes a silicon substrate, and reference numeral 15 denotes a shaft that rotatably supports the micromirror 12. Further, as shown in FIG. 4A, the tilting state in which the micromirror 12 reflects the laser light L1 incident from the laser light source 9 to the workpiece 8 side is called “ON drive”, and FIG. As shown by the solid line, the tilting state in which the light is reflected in a direction different from the workpiece 8 side is referred to as “OFF drive”.

  A control means 11 is provided connected to the laser light source 9 and the micromirror device 10. The control means 11 transfers tilt information for generating a predetermined pattern by the micromirror device 10 to the storage element 13 of the micromirror device 10, and is, for example, a personal computer (hereinafter referred to as “control PC”). . Alternatively, it may be a control circuit incorporated in the apparatus.

  An objective lens 3 is provided on the optical axis connecting the pattern generation device 2 and the stage 1 so as to face the workpiece 8 placed on the stage 1. The objective lens 3 condenses the laser light L1 whose beam cross-sectional shape is shaped by the micromirror device 10 onto the workpiece 8, and a lens holder 16 that is movable parallel to the surface of the stage 1. It consists of a plurality of types of objective lenses 3a to 3d having different magnifications that are detachably held.

  An imaging lens 4 is provided on the optical path between the pattern generation device 2 and the objective lens 3. The imaging lens 4 is combined with the objective lens 3 to form an image of the micromirror 12 of the micromirror device 10 on the workpiece 8.

  An imaging unit 5 is provided on the optical path where the optical path from the imaging lens 4 toward the pattern generation device 2 is branched by the beam splitter 16. The image pickup means 5 is provided with a plurality of light receiving elements in a matrix and picks up a two-dimensional image on the workpiece 8 and is, for example, a CCD camera or a CMOS camera.

  An illumination light source 6 is provided on the optical path where the optical path from the objective lens 3 toward the imaging lens 4 is branched by the beam splitter 17. The illumination light source 6 irradiates the workpiece 8 with illumination light L2 to enable the imaging means 5 to image the surface of the workpiece 8 and is a halogen lamp or the like.

  Displacement means 7 is provided so that the main body of the optical system including the pattern generating device 2, the objective lens 3, the imaging lens 4, the imaging means 5, and the illumination light source 6 can be moved up and down. This displacing means 7 is for adjusting the focus so that the image picked up by the image pickup means 5 becomes clear by moving the optical system main body up and down. For example, the displacement means 7 is configured by combining a motor and a gear.

  In the above optical system, the positions of the plurality of micromirrors 12 constituting the micromirror device 10 of the pattern generation device 2 and the position of the light receiving surface of the imaging means 5 are respectively conjugate with the imaging position of the objective lens 3. To be in a relationship. In FIG. 1, reference numeral 18 denotes a motor for moving the lens holder 16 in the X-axis direction, reference numeral 19 denotes a ball screw connected to the motor 18 and rotated to move the lens holder 16 in the X-axis direction, and reference numeral 20 denotes a lens. A motor for moving the holder 16 in the Y-axis direction, reference numerals 21 a to 21 d are total reflection mirrors, and reference numeral 22 is a field lens that uniformly illuminates the imaging region of the imaging means 5.

Next, the operation of the laser processing apparatus configured as described above and the pattern generation method by the pattern generation apparatus 2 will be described with reference to FIGS. In the following description, a case where one pattern is processed by repeatedly emitting the laser beam L1 at least twice will be described.
First, in step S1, an initial setting for generating a predetermined pattern by the pattern generation device 2 is performed. That is, in the control means 11 composed of the control PC, the bitmap data of the pattern corresponding to the processing pattern is generated based on the CAD data and stored in a memory (not shown). Further, the number of times of irradiation with the laser light L1, the irradiation time t1 of the laser light L1, the power of the laser light source 9, and the like are set and stored in the memory.

  The bitmap data may be stored in the control unit 11 or may be stored in a memory (not shown) provided in the micromirror device 10. Further, the processing depth may be set instead of the number of times of laser irradiation. In this case, the number of irradiation times of the laser beam L1 can be obtained by referring to a table showing the relationship between the number of irradiation times stored in advance in the control means 11, the power of the laser light source 9, and the processing depth. The irradiation time t1 of the laser beam L1 is tilt information stored in the storage element 13 of the micromirror 12 due to the leakage light L1 ′ (see FIG. 3) of the laser beam L1 that has entered from the gap between the adjacent micromirrors 12. Disappears and the time t2 until the tilted micromirror 12 starts rotating to return to the horizontal state by the elastic deformation restoring force of the shaft 15 that rotatably supports the micromirror 12 (FIG. 6B). Reference)) (t1 ≦ t2).

  When the initial setting of the pattern generating apparatus 2 is completed, the illumination light source 6 of the laser processing apparatus is turned on, the imaging means 5 is turned ON, and the optical system main body is moved to the workpiece 8 by the moving means (not shown). It is relatively moved in the axial and Y-axis directions and positioned at a predetermined position. This movement is performed based on machining position data stored in advance in the control PC, for example. At this time, any one of the objective lenses 3a to 3c having a low magnification is selected as the objective lens 3.

  Next, the displacement means 7 of the laser processing apparatus is activated, the optical system main body is moved up and down, and autofocus adjustment is performed so that the image picked up on the surface of the workpiece 8 by the image pickup means 5 becomes clear. Then, the stage 1 is further moved in the X-axis and Y-axis directions so that the processing target is positioned at the center of the objective lens 3. Thereafter, the lens holder 16 is moved in the X-axis direction by the motor 18 so that the objective lens 3 is replaced with a high-magnification objective lens 3d. If necessary, the lens holder 16 is moved in the Y-axis direction by the motor 20 to align the optical axis of the objective lens 3d with the optical axis of the optical system main body. Then, the autofocus adjustment is performed again in the same manner as described above.

  In step S2, the bitmap data of the processing pattern is transferred from the control means 11 to the micromirror device 10 (see FIG. 6A). In this case, when the bitmap data is stored in the memory of the micromirror device 10, a pattern transfer command is sent from the control means 11 to the micromirror device 10, and the bitmap data is stored in the micromirror device 10 from the memory. It may be transferred to the element 13.

  When the bitmap data is transferred to the micromirror device 10, tilt information of the micromirror 12 is stored in the storage element 13, and each micromirror 12 starts tilting based on this tilt information (FIG. 6B). )reference).

  In step S3, the control means 11 receives from the micromirror device 10 a response signal indicating that the micromirror 12 has completely tilted and the bitmap data has been correctly transferred (see FIG. 6C).

  In step S4, the reception of the response signal from the micromirror device 10 is used as a trigger to transmit a laser beam L1 emission command from the control means 11 to the laser light source 9, and the ON time of the Q switch is controlled to control the laser light source 9 from the laser. Light L1 is emitted only for time t1 (see FIG. 6D). As a result, the laser beam L1 is reflected toward the workpiece 8 by the plurality of micromirrors 12 of the micromirror device 10, and a pattern having a predetermined shape is generated on the workpiece 8. As a result, the first processing is performed by the laser beam L1.

  In step S5, the number of times of emission of the laser light L1 is counted and compared with the number of times of emission set in advance in the memory of the control means 11, and it is determined whether or not they match. Here, if the count number does not match the stored number of times of emission, the determination is “NO”, the process returns to step S2, and immediately after the emission of the laser beam L1, the same pattern as the previous time is displayed. To the micromirror device 10 (see FIG. 6A). Then, steps S2 to S5 are repeatedly executed until the count number matches the stored number of times of radiation and the determination is “YES”, and one pattern is processed by at least two laser irradiations.

  In step S4, when the laser beam L1 is irradiated to the micromirror device 10, as shown in FIG. 3, a part of the laser beam L1 enters the inside through the gap between the adjacent micromirrors 12, and the micromirror device 10 Irradiate the memory element 13 provided on the back surface of the mirror 12 to generate a photocurrent. Due to the generation of this photocurrent, the tilt information of the micromirror 12 stored in the storage element 13 disappears, and the micromirror 12 starts to return to the horizontal state by the elastic deformation restoring force of the shaft 15 that supports it. Try to do (see the dashed line in FIG. 6B). However, as described above, since the emission time t1 of the laser beam L1 is set in advance so that t1 ≦ t2, the same pattern is again formed before the micromirror 12 starts rotating to return to the horizontal state. The transfer is performed and the tilt information is stored in the storage element 13. Therefore, the tilted state of the micromirror 12 is maintained as it is (see FIG. 5B).

  In this manner, the pattern generation apparatus 2 can stably generate the pattern even when the laser beam L1 is repeatedly emitted at least twice and the same pattern is continuously generated. .

  In the above description, the case where the pattern generation apparatus 2 is applied to a laser processing apparatus has been described. However, the present invention is not limited to this, and the pattern generation apparatus 2 may be applied to an exposure apparatus. In this case, the light source of the pattern generation apparatus 2 is a laser light source 9 or a flash lamp that emits ultraviolet rays intermittently. Alternatively, the light source may be always turned on and light may be emitted intermittently by switching with the switching element.

2 ... Pattern generator 8 ... Workpiece (light irradiation object)
DESCRIPTION OF SYMBOLS 9 ... Laser light source 10 ... Micromirror device 11 ... Control means 12 ... Micromirror 13 ... Memory | storage element 15 ... Axis L1 ... Laser beam L1 '... Leakage light

Claims (6)

A plurality of micromirrors individually tilted based on the transferred pattern information are arranged in a matrix, and the micromirrors corresponding to the pattern information are respectively corresponding to the back side of each micromirror. A pattern generating method for emitting light from a light source to a micromirror device provided with a storage element for storing information, and generating a predetermined pattern on a light irradiation object by reflected light in the micromirror device,
When the same pattern is continuously generated by repeatedly emitting light from the light source to the micromirror device at least twice or more, until the number of times the light is emitted reaches a preset number of times. The memory element is caused by the leakage light of the light that has entered through the gap between the adjacent micromirrors until the next one-shot light is emitted after the one-shot light is emitted from the light source. The tilt information stored in is lost, and the same pattern information as the pattern information transferred immediately before the micromirror starts to rotate due to the elastic restoring force of the shaft supporting the micromirror A pattern generation method comprising transferring to a micromirror device. Tilt information of each micromirror is stored in a light source that intermittently emits light and a storage element provided corresponding to each of the back surfaces of a plurality of micromirrors arranged in a matrix, and based on the tilt information A micromirror device that tilts each micromirror individually and reflects light incident from the light source to generate a predetermined pattern on a light irradiation target, and pattern information corresponding to the tilt information is the micromirror A pattern generation apparatus comprising: a control unit that transfers the device to the storage element and stores the tilt information in the storage element;
When the control means causes the micromirror device to emit light from the light source intermittently at least twice or more and continuously generate the same pattern, the number of times of emission of the light is predetermined. Until the number of times reaches, the light leakage light that has entered from the gap between the adjacent micromirrors until the next one-shot light is emitted after the one-shot light is emitted from the light source. Thus, the tilt information stored in the storage element disappears, and the same pattern information transferred immediately before the micromirror starts to rotate due to the elastic restoring force of the shaft supporting the micromirror. The pattern generation apparatus is configured to transfer the pattern information and store the tilt information in the storage element. The light source according to claim 2, wherein the transfer of the pattern information emits one shot of light at the timing when a response signal indicating that was successful is returned to the control unit from the micromirror device Pattern generator. The pattern generation apparatus according to claim 2 , wherein the light source is a laser light source that emits a high-energy laser beam capable of processing an object to be irradiated with the light. 4. The pattern generating apparatus according to claim 2 , wherein the light source is an ultraviolet light emitting light source that emits ultraviolet light that sensitizes a photosensitive resin applied to an object to be irradiated with the light. The tilt information of each micromirror is stored in a laser light source that intermittently emits laser light and a storage element provided corresponding to each of the back surfaces of a plurality of micromirrors arranged in a matrix. A micromirror device that individually tilts each micromirror and reflects a laser beam incident from the laser light source to generate a predetermined pattern on a light irradiation target; and pattern information corresponding to the tilt information Control means for transferring the light irradiation object to the micromirror device and storing the tilt information in the storage element, and the light irradiation object is reflected by the laser light reflected to the light irradiation object side by the micromirror device. A laser processing apparatus for laser processing,
The control means presets the number of times the laser light is emitted when the micromirror device continuously generates the same pattern by repeatedly emitting laser light from the laser light source at least twice or more. until it reaches a predetermined number of times that is, after the laser beam shot from the laser light source is emitted, the until emission of the next shot of the laser beam is performed, entering from the gap of the micromirrors adjacent The tilt information stored in the storage element disappears due to the leaked light, and is transferred immediately before the micromirror starts to rotate due to the elastic restoring force of the shaft supporting the micromirror. The laser processing apparatus is characterized in that the same pattern information as the obtained pattern information is transferred and the tilt information is stored in the storage element.