Method and apparatus for photo-fabrication

The present invention relates to a stereolithography apparatus and method, and in particular, a stereolithography apparatus and a method for forming a structure by irradiating a photocurable substance that is cured by irradiation with light with light. Regarding the method.

PROBLEM TO BE SOLVED: To create a three-dimensional structure by moving a light irradiation position along a predetermined pattern by using a photocurable resin having a property of curing a portion irradiated with light. The stereolithography method is known (see JP-A-56-144478). In a photocurable resin, the monomers in the resin are polymerized by light absorption to polymerize and cure. Since the polymerized portion solidifies, a three-dimensional structure can be created by removing the uncured liquid portion. In this stereolithography, the photocurable resin has a large absorption at an ultraviolet wavelength (300 nm to 400 nm), and an ultraviolet laser or an ultraviolet lamp is used as a light source for stereolithography.

[0003] However, in the conventional stereolithography method by ultraviolet irradiation (hereinafter referred to as ultraviolet irradiation light modeling method), high-speed modeling is possible, but it is known that the processing accuracy is low. That is, in the ultraviolet irradiation stereolithography method, the processing accuracy is low (10 to several tens of μm) because the light is absorbed and the curing reaction occurs even in the part irradiated with light other than the condensing point, and only the laminated structure is created. Can not do it.

[0004] Therefore, in recent years, in order to improve the precision of modeling, light having a wavelength twice the absorption wavelength (600 nm to 800 nm) is irradiated instead of ultraviolet rays, and the light is absorbed by the two-photon absorption phenomenon. A modeling method for creating a three-dimensional structure (hereinafter referred to as a two-photon absorption photomodeling method) has been proposed (see Japanese Patent Publication No. 63-40650).

[0005] The two-photon absorption phenomenon has a non-linear absorption characteristic in which the absorption amount is proportional to the square of the light intensity, and has a high three-dimensional spatial resolution. Taking advantage of this feature, it is possible to create a finer structure compared to ordinary stereolithography. In general, two-photon absorption photo modeling creates a three-dimensional structure, so the structure is decomposed into a set of points and cured by shifting the irradiation position one by one, or the focused spot is irradiated with light. To create a structure by a collection of lines.

[0006] However, in order to cure a unit volume in either case of point curing or linear curing, it is necessary to absorb a certain amount of light energy or more. In particular, the two-photon absorption phenomenon has a smaller absorption probability than the absorption by the ultraviolet irradiation stereolithography method. It is possible to shorten the time by increasing the output of the light source, but if the output exceeds a certain level, the resin may be destroyed due to the occurrence of ablation or the like.

[0007] As a result, in order to create a large number of large-sized structures, the two-photon absorption stereolithography method using the two-photon absorption phenomenon has a low throughput, which poses a practical problem and shortens the creation time. I'm being shouted.

[0008] In consideration of the above facts, an object of the present invention is to obtain a stereolithography apparatus and method capable of stereolithography of a structure with high accuracy easily and in a short time.

[Means for Solving the Problems] In order to achieve the above object, the invention of claim 1 is a photocurable substance which is contained in a container and is cured by irradiation with light. In an optical modeling apparatus that forms a structure by irradiating light with an energy level required for curing, a first light source that irradiates the photocurable substance with first light and a second light that causes a multiphoton absorption phenomenon. A light source means having a second light source that irradiates the photocurable substance with the light of the above, and the light energy of the first light and the second light should be an energy level required for curing the photocurable substance. With respect to the condensing means for condensing light, the changing means for changing the condensing position by the condensing means in the container, and the structure having a predetermined shape to be shaped, at least a part of the size of the structure is determined. After the irradiation of light by the first light source and the pretreatment for changing the condensing position so as to be a predetermined small size from the size of the structure of the shape, the predetermined small size is changed to the predetermined shape. It is characterized in that it is provided with a control means for controlling the irradiation of light by the second light source and the main processing of changing the condensing position.

[0010] In the stereolithography apparatus of the present invention, a structure is formed by irradiating a photocurable substance contained in a container and cured by irradiation with light with light having an energy level required for curing the photocurable substance. To model. The light that irradiates the photocurable substance is emitted from the first light source and the second light source of the light source means. The first light source irradiates the photocurable substance with the first light. The second light source irradiates the photocurable substance with a second light that causes a multiphoton absorption phenomenon, for example, a two-photon absorption phenomenon. The light emitted from the light source means is condensed by the photocurable substance in the container by the condensing means. In this case, the light energies of the first light and the second light are focused as much as possible to the energy level required for curing the photocurable substance. The light collection position in the container is changed by the changing means. The change of the light collecting position and the light source means are controlled by the control means. The control means irradiates a structure having a predetermined shape to be formed with light by a first light source so that at least a part of the size of the structure becomes a small size predetermined from the size of the structure having the predetermined shape. It is controlled to perform preprocessing for changing the light collection position. After that, the control means controls to perform the main process of irradiating the light with the second light source and changing the condensing position from the predetermined small size to the predetermined shape. That is, in the pretreatment, rough modeling is performed, and in this treatment, fine modeling is performed. As a result, a fine structure can be formed in a short time.

[0011] The invention according to claim 2 is the optical modeling apparatus according to claim 1, wherein the changing means includes a scanning means for two-dimensionally scanning a light condensing position of light from the light source means, and the scanning means. It is characterized in that it is composed of a moving means for moving at least one position of the light collecting position and the position of the photocurable substance in a direction intersecting the scanning surface.

[0012] The focal position is preferably changed according to the shape of the structure. Therefore, since the focusing position is changed three-dimensionally, the change of the focal position can be easily changed by separating the change of the focal position by the scanning means and the moving means. That is, the scanning means two-dimensionally scans the condensing position of the light from the light source means. The moving means moves at least one of the light collecting position and the position of the photocurable substance in the direction intersecting the scanning surface.

[0013] The invention according to claim 3 is the optical modeling apparatus according to claim 1 or 2, wherein the light source means is either the light of the first light source or the light of the second light source. It is characterized by including a switching means for switching to the irradiation of light.

[0014] If the light of the first light source and the light of the second light source are both irradiated to the photocurable substance, the action of the light of the first light source and the action of the light of the second light source occur at the same time, which is not preferable. Therefore, the action of each light source can be separated by including the switching means for switching between the light of the first light source and the light of the second light source.

[0015] The invention according to claim 4 is the optical modeling apparatus according to any one of claims 1 to 3, wherein the first light source irradiates light having a wavelength in the ultraviolet wavelength range. It is a feature.

[0016] By using a light source that irradiates light having a wavelength in the ultraviolet wavelength region as the first light source, a general photocurable substance can be used, and the versatility of the stereolithography apparatus is improved.

[0017] The invention according to claim 5 is the optical modeling apparatus according to any one of claims 1 to 4, wherein the second light source includes a harmonic generating element and is derived from the first light source. It is characterized in that the irradiated light is irradiated as a second light in which the multiphoton absorption phenomenon occurs.

[0018] The second light source irradiates the second light that causes the multiphoton absorption phenomenon, but if a light source separate from the first light source is used, the size of the device becomes large. Therefore, if a harmonic generation element such as SHG is used as the second light source and the light emitted from the first light source is irradiated as the second light in which the multiphoton absorption phenomenon occurs due to the operation of the harmonic generation element, the light source is used. Can also be used, and the device can be miniaturized.

[0019] The invention according to claim 6 is the optical modeling apparatus according to claim 5, wherein the switching means transmits the light of the first optical filter and the light of the second light source. It is characterized in that it is an exchange means for exchanging with any of the optical filters of the second optical filter.

[0020] When a harmonic generating element such as SHG is used as the second light source, the light of the first light source and the light of the second light source may be close to each other or almost combined, and it may be difficult to separate them. Therefore, as the switching means, if it is configured by an exchange means for exchanging with either an optical filter of a first optical filter that transmits the light of the first light source and a second optical filter that transmits the light of the second light source. , The light of the first light source and the light of the second light source can be easily separated and used.

[0021] The function of the stereolithography apparatus can be easily achieved by the following stereolithography method. Specifically, as described in claim 7, the photocurable substance contained in the container and cured by irradiation with light is irradiated with light at an energy level required for curing the photocurable substance. In the photoforming method of modeling a structure by the above, the photoenergy of the first light irradiating the photocurable substance and the second light causing the multiphoton absorption phenomenon irradiating the photocurable substance is the photocuring. With respect to a structure having a predetermined shape to be shaped by condensing as much as possible to the energy level required for curing the sex substance, at least a part of the size of the structure is set to a small size predetermined from the size of the structure having the predetermined shape. After irradiating the first light so as to be, the second light is irradiated from the predetermined small size to the predetermined shape, and the condensing position is changed in the container. , The present invention is characterized in that a structure having the predetermined shape is formed.

[0022] The invention according to claim 8 is the stereolithography method according to claim 7, wherein the light-collecting position is two-dimensionally scanned and the light-collecting position is scanned in a direction intersecting the scanning surface. And by moving at least one of the positions of the photocurable substance, the light collecting position is changed in the container.

[0023] The invention according to claim 9 is the stereolithography method according to claim 7 or 8, and when the photocurable substance is irradiated, the first light and the second light are used. It is characterized by switching to irradiation of either one of light.

[0024] The invention according to claim 10 is the stereolithography method according to any one of claims 7 to 9, wherein the first light is light having a wavelength in the ultraviolet wavelength range. It is characterized by that.

[0025] The invention according to claim 11 is the optical modeling method according to any one of claims 7 to 10, wherein the second light generates harmonics from the first light. The light is characterized in that the multiphoton absorption phenomenon caused by the phenomenon occurs.

[0026] The invention according to claim 12 is the optical modeling method according to claim 11, wherein when the photocurable substance is irradiated, the first optical filter that transmits the first light and the said. It is characterized in that it is replaced with an optical filter that is one of the second optical filters that transmit the second light.

[Embodiments of the Invention] Hereinafter, an example of the embodiments of the present invention will be described in detail with reference to the drawings. The present embodiment is an application of the present invention to a stereolithography apparatus.

[0028] In order to cure a unit volume by stereolithography, it is necessary to absorb a certain amount of light energy or more. In particular, the two-photon absorption phenomenon has a smaller absorption probability than normal light absorption. Therefore, it is possible to shorten the time by increasing the output of the light source, but if the output exceeds a certain level, the resin will be destroyed due to the occurrence of ablation or the like. According to experiments, the present inventors have conducted an experiment in a practical light source output range, and for curing a resin by a two-photon absorption stereolithography method, about 0.01 s / μm.³It was found that the above irradiation time is required. Therefore, the volume V (μm)³), At least V × 0.01 (s) of time is required to create the structure.

[0029] In this two-photon absorption stereolithography method, in order to produce a large number of large-sized structures, the throughput is low, which poses a practical problem, and there is a demand for shortening the production time.

[0030] On the other hand, in the ultraviolet irradiation stereolithography method, when light of the same power as two-photon absorption is irradiated, 1e per unit volume.^-8s / μm³It is possible to cure the resin at this speed, which is orders of magnitude faster than two-photon absorption stereolithography. However, the ultraviolet irradiation stereolithography method absorbs light everywhere other than the condensing point and causes a curing reaction, so the processing accuracy is inferior to that of two-photon absorption stereolithography (10 ~). Several tens of μm).

Therefore, in the present embodiment, high-speed and high-precision stereolithography is achieved by continuously performing the two-photon absorption stereolithography after performing the coarse stereolithography by the ultraviolet irradiation stereolithography method. Realize.

FIG. 1 shows a schematic configuration of the stereolithography apparatus 10 according to the first embodiment to which the present invention is applicable. The stereolithography apparatus 10 of the present embodiment includes a light source unit 16 composed of a first laser light source 12 and a second laser light source 14. The light source unit 16 composed of the first laser light source 12 and the second laser light source 14 is connected to a control device 50 that controls the process for stereolithography according to a predetermined pattern (FIG. 2).

[0033] The first laser light source 12 is a light source for performing stereolithography by a conventional ultraviolet irradiation light molding method, and in this embodiment, a He-Cd laser having an oscillation wavelength of 325 nm and an output of 10 mW is used. .. In the present embodiment, a case where a laser light source is used as the first laser light source 12 by the ultraviolet irradiation stereolithography method will be described, but the present invention is not limited to this, and light in the ultraviolet wavelength range is emitted. Any light source can be used. For example, a Nd: YAG-3 harmonic laser or a discharge lamp such as a mercury lamp may be used.

[0034] The second laser light source 14 is a light source for performing stereolithography by the two-photon absorption stereolithography method, and in the present embodiment, a Ti: Sapphire pulse laser is used. This Ti: Sapphire pulsed laser is a pulsed laser that oscillates at an oscillation wavelength of 700 nm, a pulse width of 100 fs (femtoseconds), and a repetition frequency of 100 MHz, and can obtain an average output of 10 mW. In the present embodiment, a case where a Ti: Sapphire pulse laser is used as the second laser light source 14 by the two-photon absorption stereolithography method will be described, but the present invention is not limited thereto. The second laser light source 14 may be a light source that produces light modeling by the two-photon absorption stereolithography method, but if a Ti: Sapphire pulse laser is used, the output peak can be increased with a short pulse, and the two-photon absorption phenomenon can be performed efficiently. Can be generated.

A dichroic mirror 18 is provided on the emission side of the first laser light source 12, and a reflection mirror 22 is provided on the emission side of the second laser light source 14. The dichroic mirror 18 reflects the laser beam emitted by the first laser light source 12 and transmits the laser beam emitted by the second laser light source 14, and specifically, transmits light having a wavelength in the vicinity of 700 nm. Moreover, it reflects the desired light with a wavelength of 325 nm. The reflection mirror 22 only needs to be able to reflect the laser beam emitted from at least the second laser light source 14, and specifically, it reflects light having a wavelength in the vicinity of 700 nm.

[0036] The dichroic mirror 18 is attached to a first drive unit 20 for deflecting the reflected light in a biaxial direction intersecting the optical axis. This is because the spot light is scanned two-dimensionally. Similarly, the reflection mirror 22 is attached to a second drive unit 24 for deflecting the reflected light in the biaxial direction intersecting the optical axis.

[0037] A light modulation mechanism 26 and a condenser lens 28 are provided in order on the reflection side of the dichroic mirror 18 and the reflection mirror 22.

[0038] The optical modulation mechanism 26 switches the passing laser beam to light shielding or light transmission, and will be described using an acousto-optic modulation element (AOM) in the present embodiment. It is not limited as long as it has a mechanism capable of switching the passing laser beam to light shielding or light transmission. For example, a mechanical shutter that mechanically blocks or opens light, an electro-optical modulation element (EOM) that switches to light-shielding or translucent by an electro-optical effect, an LCD shutter that switches to light-shielding or translucent by a liquid crystal, or the like can be used.

[0039] The condensing lens 28 is for condensing the incident laser beam in a spot shape, and is attached to a moving mechanism 30 for adjusting the movement of the condensing lens 28 in the direction along the optical axis. There is. In the present embodiment, the condenser lens 28 uses a lens system having an NA of 0.8. The adjustment of the condensing position by deflecting the reflection angle of the dichroic mirror 18 and the reflection mirror 22 and adjusting the movement of the condensing lens 28 functions as a condensing point moving mechanism.

[0040] In the above description, the case where the laser beams from the first laser light source 12 and the second laser light source 14 are focused by a single focusing lens 28 will be described, but the present invention is limited thereto. Instead, each laser beam may be configured as an independent optical system.

[0041] On the condensing side of the condensing lens 28, a container 40 placed on a desk (base plate 46) is located. The container 40 is placed at a predetermined position on the base plate 46. The base plate 46 is provided with a vertical movement mechanism 48. The vertical movement mechanism 48 is composed of a support column 38, an arm 36, a pole 34, a support plate 32, and a vertical drive unit 44.

That is, a support plate 38 to which the arm 36 located above the container 40 is attached is fixed on the base plate 46, and a support plate 32 for holding a modeled object is attached to the tip of the arm 36. The pole 34 is pivotally supported so that it can move up and down. The vertical movement of the pole 34 is performed by the vertical drive unit 44. The support plate 32 can be embedded in the photocurable resin 42 housed in the container 40, and the distance between the support plate 32 and the liquid level of the photocurable resin 42 can be adjusted by moving the container 40 up and down. That is, the support plate 32 is moved up and down by the operation of the vertical movement mechanism 48, and the container 40 is moved up and down accordingly. The support plate 32 may be a substantially transparent flat plate, and for example, a flat plate such as glass or acrylic can be used.

As shown in FIG. 2, the control device 50 is connected to the first laser light source 12 and the second laser light source 14, and emits the laser beams of the first laser light source 12 and the second laser light source 14. To control. Further, a first drive unit 20 for deflecting the reflection angle of the dichroic mirror 18 and a second drive unit 24 for deflecting the reflection angle of the reflection mirror 22 are also connected to the control device 50. Further, the optical modulation mechanism 26, the moving mechanism 30, and the vertical drive unit 44 are also connected to the control device 50. The control device 50 is configured to include a computer including a CPU, ROM, and RAM, and is for controlling the drive of each part by a processing routine described later to perform modeling processing.

[0044] The control device 50 can be provided with a floppy disk unit (FDU) into which a floppy disk (FD) as a recording medium can be inserted and removed. The processing routines described later can be read and written to the floppy disk FD using the FDU. Therefore, the processing routine described later may be recorded in the FD in advance, and the processing program recorded in the FD may be executed via the FDU. Further, a large-capacity storage device (not shown) such as a hard disk device is connected to the control device 50, and the processing program recorded on the FD is stored (installed) in the large-capacity storage device (not shown) and executed. May be good. Further, as a recording medium, there are an optical disk such as a CD-ROM and a DVD, a disk such as a magneto-optical disk such as MD and MO, and a magnetic tape such as a DAT. -ROM devices, DVD devices, MD devices, MO devices, tape decks, etc. may be used.

Next, the process of modeling the structure by the stereolithography method according to the present embodiment will be described. In the present embodiment, the structure is roughly shaped by the ultraviolet irradiation stereolithography method, and then finely shaped by the two-photon absorption stereolithography method.

[0046] The processing routine shown in FIG. 3 is executed by the control device 50. First, in step 100, the structural data of the structure to be modeled is read. This structural data includes CAD data and scan data used to incorporate the structure into a modeling model for numerical analysis, and in step 100, a modeling model is created from this structural data. This modeling model is a numerical value of the modeling model in the input data format to the computer program created based on the numerical and analytical methods.

In the next step 102, the modeling model is decomposed into a grid pattern. Here, a space of a predetermined size (in the present embodiment, the container 40) is divided so as to be a decomposition block of a cube having a side of 10 μm. This predetermined size of space is the volume that completely contains the modeling model of the structure to be modeled. Then, when the modeling model is installed in this space, it corresponds to disassembling the modeling model in a grid pattern, and it is possible to obtain the correspondence between the position of the above-mentioned decomposition block and the position of the modeling model. In the next step 104, the decomposition blocks completely contained in the modeling model are extracted.

[0048] In the next step 106, a control signal for driving the vertical drive unit 44 is output so that the distance between the upper surface of the support plate 32 and the liquid level of the photocurable resin 42 is 10 μm. This is a cube (1000 μm) whose side is 10 μm in the amount of modeling by the ultraviolet irradiation stereolithography method in the present embodiment.³). Therefore, it is possible to change the value in step 102 according to the amount of modeling by the ultraviolet irradiation stereolithography method. In the next step 108, a control signal for driving the first laser light source 12 so that the laser beam is emitted from the first laser light source 12 is output in order to perform stereolithography by the ultraviolet irradiation stereolithography method. At this point, the control device 50 outputs a control signal to the light modulation mechanism 26 so as to block the laser beam.

[0049] In the next step 110, among the decomposition blocks extracted in the above step 104, the lowest layer decomposition block is stereolithographically formed. Here, by outputting a control signal to the first drive unit 20 and the moving mechanism 30, the photocurable resin 42 in the two-dimensional plane is irradiated with a laser beam and cured. Further, the control device 50 outputs a control signal to the optical modulation mechanism 26 so as to transmit the laser beam according to the position (pattern) of the decomposition block.

[0050] In the next step 112, it is determined whether or not the modeling is completed for all the layers of the modeling model, and if it is denied, the process proceeds to step 114. In step 114, in order to make the layer for which modeling is completed the lowest layer, the control signal for driving the vertical drive unit 44 is output so that the distance between the upper surface of modeling and the liquid level is 10 μm, and then the process returns to step 110. Repeat the process.

On the other hand, when the modeling by the ultraviolet irradiation stereolithography method is completed, it is affirmed in step 112, and the process proceeds to step 116, and the modeling model is decomposed into fine grids. Here, a space of a predetermined size (in the present embodiment, the container 40) is divided into fine blocks of a cube having a side of 1 μm. Similar to the above, when the modeling model is installed in this space, it corresponds to disassembling the modeling model into fine grids, and the correspondence between the position of the above decomposition block and the position of the modeling model is obtained. be able to. In the next step 118, fine blocks that are completely included in the modeling model and are not included in the decomposition block are extracted.

[0052] Note that the extraction of fine blocks is not limited to being completely included in the modeling model. For example, when a part of the fine block exists outside the modeling model, the ratio of the protrusion amount to the volume of the fine block may be equal to or less than a predetermined ratio.

[0053] In the next step 120, a control signal for driving the vertical drive unit 44 is output so that the distance between the upper surface of the support plate 32 and the liquid level of the photocurable resin 42 is 1 μm. This is because the amount of modeling by the two-photon absorption stereolithography method in the present embodiment, that is, the accuracy is about 1 μm.³Due to the fact that Therefore, it is possible to change the value in step 120 according to the amount of modeling by the two-photon absorption stereolithography method. In the next step 122, a control signal for driving the second laser light source 14 so that the laser beam is emitted from the second laser light source 14 is output in order to perform photo modeling by the two-photon absorption stereolithography method. That is, the emission of the laser beam is switched from the first laser light source 12 to the second laser light source 14. At this point, the control device 50 outputs a control signal to the light modulation mechanism 26 so as to block the laser beam.

[0054] In the next step 124, among the fine blocks extracted in the above step 118, the lowest layer fine block is stereolithographically formed. Here, by outputting a control signal to the second drive unit 24 and the moving mechanism 30, the photocurable resin 42 in the two-dimensional plane is irradiated with a laser beam and cured. Further, the control device 50 outputs a control signal to the optical modulation mechanism 26 so as to transmit the laser beam according to the position (pattern) of the decomposition block.

[0055] In the next step 126, it is determined whether or not the modeling is completed for all the layers of the modeling model, and if it is denied, the process proceeds to step 128. In step 128, in order to make the layer for which modeling is completed the lowest layer, the control signal for driving the vertical drive unit 44 is output so that the distance between the upper surface of modeling and the liquid level is 1 μm, and then the process returns to step 124. Repeat the process.

On the other hand, when the modeling by the two-photon absorption stereolithography method is completed, it is affirmed in step 126, and the process proceeds to step 130 to perform the cleaning process. That is, the cured photocurable resin 42 is taken out, and the uncured photocurable resin 42 is washed away by spraying or burying a solvent that is soluble in the uncured portion and insoluble in the cured portion, for example, methanol.

[0057] As described above, in the present embodiment, after the coarse stereolithography by the ultraviolet irradiation stereolithography is performed, the fine optical modeling by the two-photon absorption stereolithography is continuously performed, so that the ultraviolet irradiation stereolithography is used. It is possible to realize optical modeling that enables microstructure modeling by the two-photon absorption stereolithography method while realizing high-speed processing.

[0058] In the present embodiment, the case where the photocurable resin 42 is cured from the liquid surface of the photocurable resin 42 has been described, but the present invention is not limited to this. For example, a transparent container may be used so as to be laminated from the top layer on the bottom surface of the support plate across the container.

An example of creating a structure formed by stereolithography according to the present embodiment will be described.

[0060] FIG. 4 shows an outline of the created structure. FIG. 4 (A) is an arrow view showing the appearance of the structure, and FIG. 4 (B) is a partially enlarged view. This structure has a square shape with a side of 5 mm, and a ridge with a width of 1 μm and a height of 1 μm formed in a stripe shape on a substrate having a thickness of 100 μm at a pitch of 5 μm. This structure is used for purposes such as spectroscopy known as a diffraction grating.

[0061] The structure shown in FIG. 4 could not be obtained by performing coarse stereolithography by the ultraviolet irradiation stereolithography method due to its high accuracy. On the other hand, in the implementation of fine optical stereolithography by the two-photon absorption stereolithography method, the processing accuracy was sufficient, but the structure could not be obtained in a practical modeling time.

That is, the volume of the structure shown in FIG. 4 is 2.5 e for the substrate portion.⁹(μm³) = 5000 × 5000 × 100, and the stripe part is 5e⁶(μm³) = 1 × 1 × 5000. Therefore, when modeling by the two-photon absorption stereolithography method, the modeling time of the substrate part becomes dominant, and 2.5e⁹(μm³) × 0.01 (s / μm)³) = 2.5e⁷Requires (s: seconds) = 289 (day: day).

[0063] On the other hand, when the present embodiment is applied, the ultraviolet irradiation stereolithography method is used for modeling the substrate portion, and the two-photon absorption stereolithography method is used for modeling the stripe portion. The modeling time is 2.5e for the board part.⁹(μm³) × 1e^-8(s / μm³) = 25 (s: sec), the stripe part is 5e⁶(μm³) × 0.01 (s / μm)³) = 14 (h: time), and it is possible to create a structure with the required accuracy in a short time of about 14 hours.

[0064] Next, a second embodiment will be described. Since the present embodiment has almost the same configuration as the above-described embodiment, the same parts are designated by the same reference numerals and detailed description thereof will be omitted.

[0065] In the above embodiment, a light source for optical modeling by the ultraviolet irradiation stereolithography method and a light source for optical modeling by the two-photon absorption stereolithography method are separately provided to emit a laser beam. Although it is configured, it is costly to provide two types of light sources, which is not preferable for the stereolithography apparatus 10 as a whole. Therefore, in the present embodiment, it is possible to realize optical modeling that enables microstructure modeling by the two-photon absorption stereolithography method while realizing high-speed processing by the ultraviolet irradiation stereolithography method using a single light source.

[0066] FIGS. 5 and 6 show a schematic configuration of the stereolithography apparatus 10 according to the second embodiment to which the present invention is applicable. The stereolithography apparatus 11 of the present embodiment is composed of only the second laser light source 14 as the light source unit 16. That is, the second laser light source 14 is a light source for carrying out optical modeling by the two-photon absorption stereolithography method, and uses a pulse laser having an oscillation wavelength of 700 nm. Therefore, the first laser light source 12, the dichroic mirror 18, and the first drive unit 20 that belong to the first laser light source 12 are all unnecessary.

[0067] A wavelength conversion unit 58 is provided on the injection side of the second laser light source 14. The wavelength conversion unit 58 is an optical element that converts a part of the 700 nm laser beam emitted from the second laser light source 14 into a 350 nm laser beam. By this wavelength conversion unit 58, the SHG-converted laser beam and the SHG-converted laser beam that pass through as they are are propagated substantially coaxially. For example, the wavelength converter 58 has a nonlinear optical crystal that generates a second harmonic (SHG), and BBO is an example of an element. This BBO can generate a 350 nm laser beam from a 700 nm laser beam. Since the second laser light source 14 of the present embodiment has a short pulse and a high peak value of the output power, the non-linear effect is efficiently exhibited, and SHG can be generated with high conversion efficiency. When BBO was used, SHG-converted light of 5 mW or more could be obtained with an average excitation power of 40 mW.

[0068] On the reflection side of the reflection mirror 22 provided on the emission side of the second laser light source 14, a filter mechanism 60 is provided at a position corresponding to the dichroic mirror 18 in FIG. The filter mechanism 60 includes a first optical filter 62 and a second optical filter 64, and the first optical filter 62 and the second optical filter 64 are attached to the insertion / extraction portion 66. The insertion / extraction unit 66 is connected to the control device 50, and is driven by a control signal from the control device 50 so that the optical filter of either the first optical filter 62 or the second optical filter 64 is inserted into the optical path. Will be done.

[0069] The first optical filter 62 is a filter that transmits ultraviolet rays in order to realize stereolithography by the ultraviolet irradiation stereolithography method, and specifically, is an optical filter that transmits SHG-converted light. The second optical filter 64 is a filter that blocks ultraviolet rays in order to realize stereolithography by the two-photon absorption stereolithography method, and specifically, is an optical filter that blocks SHG-converted light.

[0070] With the above configuration, the process of modeling the structure follows the same flow as in FIG. In this case, in the control device 50, the setting of the first laser light source 12 in step 108 of FIG. 3 is replaced with the insertion of the first optical filter 62, and the setting of the second laser light source 14 in step 122 is changed to the second optical filter. Control instead of inserting 64.

[0071] As described above, in the present embodiment, coarse light modeling by the ultraviolet irradiation stereolithography method and light modeling by the two-photon absorption stereolithography method can be realized by a single light source, so that in addition to the effects of the above embodiment. , Will have the following further effects. First, by unifying the light source, the device can be formed at low cost. Second, since two wavelengths can be generated coaxially by wavelength conversion by SHG, complicated work such as optical adjustment for each light source can be reduced.

[Effects of the Invention] As described above, according to the present invention, after pretreatment of light irradiation by the first light source, a second light in which a multiphoton absorption phenomenon occurs by the second light source is produced. Since the structure is formed by performing this treatment of irradiating the photocurable substance, there is an effect that a fine structure can be formed in a short time.

BRIEF DESCRIPTION OF THE DRAWINGS [Fig. 1] Fig. 1 is a schematic view of the appearance of a stereolithography apparatus according to a first embodiment of the present invention.

FIG. 2 is an image diagram showing a schematic configuration of a stereolithography apparatus.

FIG. 3 is a flowchart showing a processing flow of a control device for explaining the operation of the stereolithography device according to the present embodiment.

FIG. 4 shows an outline of the created structure, (A) shows an external view of the structure, and (B) shows a partial enlargement.

FIG. 5 is a schematic external view of a stereolithography apparatus according to a second embodiment of the present invention.

FIG. 6 is an image diagram showing a schematic configuration of a stereolithography apparatus according to a second embodiment of the present invention.

[Description of code] 10 Optical modeling device 11 Optical modeling device 12 Laser light source 14 Laser light source 16 Light source unit 18 Dichroic mirror 20 Drive unit 22 Reflective mirror 24 Drive unit 26 Optical modulation mechanism 28 Condensing lens 30 Moving mechanism 32 Support plate 40 Container 42 Photocurable resin 48 Vertical movement mechanism 50 Control device