KR102497174B1 - A double patterning method and apparatus in two-photon stereolithography - Google Patents

Abstract

The present invention is (a) preparing the glass substrate part on the upper surface of the stage part, (b) dropping the photocurable resin on the upper surface of the glass substrate part, (c) irradiating the first laser irradiated from the laser irradiation part to the photocurable resin (d) firstly growing the photocurable resin while being cured and crosslinked by the first laser, (e) irradiating the firstly grown photocurable resin with a second laser irradiated from the laser irradiation unit, (f) ) Secondary growth while the firstly grown photocurable resin is cured and crosslinked by a second laser, and (g) 3D printing of the three-dimensional structure, which is the first and secondly grown photocurable resin, Provided is a double patterning method and apparatus for two-photon stereolithography characterized in that deformation of a three-dimensional structure is minimized as first and second lasers irradiated from a laser irradiation unit are irradiated onto the photocurable resin.

Description

A double patterning method and apparatus in two-photon stereolithography

The present invention relates to a double patterning method and apparatus for two-photon stereolithography, and more particularly, by irradiating a photocurable resin with a first laser and then irradiating the same location of the photocurable resin with a second laser in the same pattern to form a three-dimensional structure. It relates to a double patterning method and apparatus of two-photon stereolithography for 3D printing.

The 3D printing process has the advantage of being able to produce a three-dimensional shape with a simpler process than the existing process, and the production time is short, and above all, it is used in various industrial fields due to the advantage that it can be freely applied to various shapes.

In addition, the 3D printing process is getting more attention as the demand for multi-products in small quantities increases in the era of the 4th industrial revolution.

In general, 3D printing technology is a technology of manufacturing a 3D shape by a layer-by-layer method, and 3D printing is performed by slicing 3D CAD data, dividing it into several layers, and stacking each layer one by one.

The 3D printing technology described above is classified into an SLS method, an SLA method, an LCD method, an MSLA method, a DLP method, and the like according to a manufacturing method.

In the case of the SLA method, a three-dimensional structure is 3D printed by curing the photocurable resin by irradiating a laser with the photocurable resin.

In this regard, the laser cross-links the polymer of the photocurable resin. At this time, the degree of curing varies according to the output (P: power) of the laser.

Specifically, when the energy of the irradiated laser is high, cross-linking increases and the distance between polymer-chains decreases.

On the other hand, when the energy of the irradiated laser is low, the cross-linking is small and the gap between the polymer chains is widened.

At this time, the three-dimensional shape produced in the process of developing absorbs the surrounding solvent, and the amount of the solvent absorbed varies according to the spacing of the polymer-chain.

When the polymer chain interval of the pattern produced by the low laser power is widened, the free-volume in which the surrounding solvent molecules can be absorbed increases, so that the solvent is well absorbed.

Accordingly, deformation occurs in the polymer network (polyer-network) by absorption of the solvent, and for this reason, shape deformation occurs.

Accordingly, there is a problem in that a peeling phenomenon occurs even in a thin film structure manufactured by a nano-stereolithography process, which is a type of SLA method.

In addition, when the power of the laser is increased to solve the above-described peeling phenomenon, the solvent of the photocurable resin is vaporized by the high-power laser to generate bubbles on the surface, or the photocurable resin is burned by the high-power laser. There was a problem.

(Patent Document 1) Patent Publication No. 10-2016-0058770 (May 25, 2016)

(Patent Document 2) Patent Publication No. 10-2019-0067403 (2019.06.17.)

An object of the present invention to solve the above problem is to irradiate a first laser with a photocurable resin to 3D print an initial three-dimensional structure, and then irradiate a second laser with the same pattern at the same location of the photocurable resin to create a three-dimensional structure. An object of the present invention is to provide a double patterning method and apparatus for two-photon stereolithography that minimizes peeling, bubble defects, and burning by 3D printing a structure.

The technical problem to be achieved by the present invention is not limited to the above-mentioned technical problem, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

The configuration of the present invention for achieving the above object is (a) preparing a glass substrate portion on the upper surface of the stage portion; (b) dropping a photocurable resin on the upper surface of the glass substrate; (c) irradiating the photocurable resin with a first laser irradiated from a laser irradiation unit; (d) firstly growing the photocurable resin while being cured and crosslinked by the first laser; (e) irradiating the firstly grown photocurable resin with a second laser irradiated from the laser irradiation unit; (f) secondarily growing the firstly grown photocurable resin while being cured and crosslinked by the second laser; and (g) 3D-printing the three-dimensional structure, which is the first and secondly grown photocurable resin, as the first and second lasers emitted from the laser irradiation unit irradiate the photocurable resin. Provided is a double patterning method of two-photon stereolithography characterized in that the deformation of the three-dimensional structure is minimized.

In an embodiment of the present invention, in steps (c) and (e), the laser irradiation unit may be a Ti: Sapphire laser having an ultra-short pulse duration of 100 fs or less. there is.

In an embodiment of the present invention, the step (c) may include: (c1) irradiating, by the first laser, a laser focus portion to be cured in the photocurable resin; (c2) forming a voxel (Volume of Pixel), which is an area where the first laser is focused on the irradiated laser focusing part and is locally cured; (c3) moving the stage unit in at least one of the x-axis direction, the y-axis direction, and the z-axis direction when a predetermined process is not completed by the control unit; and (c4) returning to step (c1), wherein in step (c3), when the preset process is completed, step (d) is performed.

In an embodiment of the present invention, step (d) may include (d1) curing the voxel by the first laser; (d2) cross-linking the cured voxel; and (d3) forming an initial 3D structure while the cross-linked voxels overlap and grow first.

In an embodiment of the present invention, the voxel may be formed long in the z-axis direction.

In an embodiment of the present invention, the step (e) may include: (e1) re-irradiating the laser focus portion irradiated by the first laser with the second laser; (e2) reshaping the voxel (Volume of Pixel) by concentrating the second laser on a laser focusing part irradiated by the first laser; (e3) moving the stage unit in at least one of the x-axis direction, the y-axis direction, and the z-axis direction when the predetermined process is not completed by the control unit; and (e4) returning to step (e1), wherein in step (e3), when the preset process is completed, step (f) is performed.

In an embodiment of the present invention, step (f) may include: (f1) re-curing the voxel by the second laser; (f2) re-crosslinking the cured voxels; and (f3) forming a 3D structure by overlapping the recrosslinked voxels and performing secondary growth.

In an embodiment of the present invention, the photocurable resin may be Su-8, which is an epoxy-based polymer resin.

In addition, the configuration of the present invention for achieving the above object is a stage unit; a glass substrate portion positioned on an upper surface of the stage portion; a laser irradiation unit positioned on the same straight line as the stage unit to generate a first laser and a second laser; a first reflector positioned between the stage part and the laser irradiation part to reflect the first and second lasers in an upward direction, and first and second reflectors positioned above the first reflector and reflected by the first reflector; A second reflector that reflects the laser in one direction and a third reflector that is located above the glass substrate portion parallel to the second reflector and reflects the first and second lasers reflected by the second reflector downward. a reflection unit including a unit; a lens unit disposed between the glass substrate unit and the third reflector and condensing the first and second lasers reflected by the third reflector onto a photocurable resin disposed on an upper surface of the glass substrate unit; an image photographing unit arranged to face the glass substrate and photographing the photocurable resin in real time; and a control unit for controlling the operation of the stage unit, the output of the laser irradiation unit, and the operation of the imaging unit, wherein the first and second lasers irradiated from the laser irradiation unit are irradiated onto the photocurable resin, thereby forming the three-dimensional image. Provided is a double patterning device for two-photon stereolithography characterized in that deformation of a structure is minimized.

In an embodiment of the present invention, the laser irradiation unit generates the second laser when the photocurable resin is cured and crosslinked by the first laser after generating the first laser, and generates the second laser by the second laser. It may be characterized in that the cured and crosslinked photocurable resin is cured and crosslinked again to 3D print a three-dimensional structure.

In an embodiment of the present invention, the laser irradiation unit may be a Ti:Sapphire laser having an ultrashort pulse duration of 100 fs or less.

In an embodiment of the present invention, the controller may move the stage in at least one of an x-axis direction, a y-axis direction, and a z-axis direction when a predetermined process is not completed.

In an embodiment of the present invention, the laser irradiation unit may irradiate the first laser to the photocurable resin.

In an embodiment of the present invention, the double patterning device for two-photon stereolithography, characterized in that the laser irradiation unit irradiates the second laser to the primarily grown photocurable resin.

The effect of the present invention according to the configuration as described above is to 3D print the first three-dimensional structure by irradiating the first laser with the photocurable resin, and then irradiate the second laser in the same pattern at the same location of the photocurable resin to create a three-dimensional structure. By 3D printing, it is possible to minimize peeling, bubble defects, and burning.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is a view showing a peeling phenomenon generated in a 3D printed 3D nanostructure according to the prior art.
2 is a conceptual diagram illustrating a double patterning device for two-photon stereolithography according to an embodiment of the present invention.
3 is a flowchart illustrating a double patterning method of two-photon stereolithography according to an embodiment of the present invention.
4 is a conceptual diagram illustrating a two-photon stereolithography process using a double patterning device for two-photon stereolithography according to an embodiment of the present invention.
FIG. 5 is a diagram illustrating energy distribution and voxel shapes in a laser focus part in a photocurable resin through a double patterning device for two-photon stereolithography according to an embodiment of the present invention.
6(a) and (b) are conceptual diagrams showing solvent absorption and shape deformation according to the output of a laser irradiation unit in the double patterning method of two-photon stereolithography according to an embodiment of the present invention.
7 (a) and (b) are diagrams comparing the surface peeling phenomenon of a three-dimensional structure manufactured through a double patterning method of two-photon stereolithography according to an embodiment of the present invention and the prior art.
8(a) and (b) are views comparing surface bubble defects and burning phenomena of a 3D structure manufactured through a double patterning method of two-photon stereolithography according to an embodiment of the present invention and the prior art. am.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and, therefore, is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, combined)" with another part, this is not only "directly connected", but also "indirectly connected" with another member in between. "Including cases where In addition, when a part "includes" a certain component, it means that it may further include other components without excluding other components unless otherwise stated.

Terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "include" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1. Two-photon stereolithography double patterning device 100

Hereinafter, a double patterning apparatus for two-photon stereolithography according to an embodiment of the present invention will be described with reference to FIG. 2 .

2 is a conceptual diagram illustrating a double patterning device for two-photon stereolithography according to an embodiment of the present invention.

The double patterning device 100 for two-photon stereolithography according to an embodiment of the present invention is a 3D printer that 3D prints a 3D structure by slicing shape information included in a 3D CAD file and stacking the divided layers one by one.

In the present invention, the 3D printing method can be classified as an SLA method, and according to the present invention, a 3D structure can be manufactured with nano-level precision.

As shown in FIG. 2, the present invention for this purpose includes a stage unit 110, a glass substrate unit 120, a laser irradiation unit 130, a reflector 140, a lens unit 150, a control unit 160, and an image capturing unit. 170, and the first and second lasers irradiated from the laser irradiation unit 130 having different outputs minimize deformation of the 3D structure as the photocurable resin is irradiated.

The stage unit 110 is a flat plate and supports the glass substrate unit 120 . In addition, the stage unit 110 moves the glass substrate unit 120 as it moves in the direction of any one of the x-axis, y-axis, and z-axis under the control of the control unit 160 .

The stage unit 110 for this may include an xyz piezo stage having a resolution of 0.1 nm to which a photocurable resin is fixed and a motor stage for moving the xyz piezo stage.

The glass substrate part 120 is made of transparent glass, has a predetermined thickness, and is positioned on the upper surface of the stage part 110 .

A photocurable resin is positioned on the upper surface of the glass substrate unit 120 . Here, the photocurable resin may be Su-8, which is an epoxy-based polymer resin.

The laser irradiation unit 130 is located on the same straight line as the stage unit 110 and generates a first laser and a second laser with different outputs.

Specifically, the laser irradiator 130 may be a Ti:Sapphire laser having an ultrashort pulse duration of 100 fs or less.

In addition, the laser emitter 130 generates the first laser with an output of any one of 45mW and 55mW under the control of the controller 160 .

Meanwhile, when the photocurable resin is cured and crosslinked by the first laser after the first laser is irradiated, the laser irradiator 130 emits a second laser with an output of either 15mW or 30mW under the control of the controller 160. generate

That is, the laser irradiator 130 generates a first laser and then generates a second laser when the photocurable resin is cured and crosslinked by the first laser.

Thereafter, the photocurable resin cured and crosslinked by the second laser is cured and crosslinked again, so that a three-dimensional structure is 3D printed.

Here, when the laser irradiation unit 130 generates only the first laser, surface peeling, defective surface bubbles, and burning occur in the 3D printed 3D structure as in the prior art.

Accordingly, in the present invention, when the laser irradiator 130 generates the first laser with an output of either 45mW or 55mW, the 3D structure is primarily 3D printed by the first laser.

Thereafter, when the laser irradiator 130 generates a second laser with an output of either 15mW or 30mW, the 3D structure is secondarily 3D printed by the second laser, resulting in surface peeling and surface bubbles compared to the case of single irradiation. Defects and burning can be improved.

In addition, in the present invention, it has been described that the laser irradiation unit 130 generates a first laser with an output of any one of 15mW and 30mW, and generates a second laser with an output of any one of 45mW and 55mW, but is not limited thereto. No, and lasers can be generated with other outputs.

The reflector 140 includes a first reflector 141 , a second reflector 142 and a third reflector 143 .

The first reflector 141 is positioned between the stage unit 110 and the laser irradiation unit 130 to reflect the first and second lasers upward.

Specifically, the first reflection part 141 is located on the same straight line as the stage part 110 and the laser irradiation part 130 .

In addition, the first reflector 141 is disposed at an angle of 45° to the ground so that the first and second lasers irradiated from the laser irradiator 130 can be reflected in an upward direction (in an upward direction in the x-axis).

The second reflector 142 is positioned above the first reflector 141 to reflect the first and second lasers reflected by the first reflector 141 in one direction.

Specifically, the second reflector 142 is located on the same straight line as the first reflector 141 .

In addition, the second reflector 142 is disposed at an angle of 45° to the ground so that the first and second lasers can be reflected in one direction (left direction in the y-axis).

The third reflector 143 is positioned above the glass substrate 120 parallel to the second reflector 142 and reflects the first and second lasers reflected by the second reflector 142 downward.

Specifically, the third reflector 143 is disposed parallel to the second reflector 142 in the x-axis and has an angle of 45° to the ground so that the first and second lasers can be reflected in the lower direction (downward in the z-axis). arranged to achieve

The lens unit 150 is located between the glass substrate unit 110 and the third reflector 143, and transmits the first and second lasers reflected by the third reflector 143 to the upper surface of the glass substrate unit 110. condensed with chemical resin.

Specifically, the lens unit 150 is positioned on the same straight line as the glass substrate unit 110 and the third reflector 143 .

In addition, the lens unit 150 may be an oil-immersion objective lens (X 100) having a numerical aperture of 1.4, and the lens unit 150 condenses the first and second lasers into a photocurable resin to form a photocurable property. cures the resin.

The control unit 160 controls the operation of the stage unit 110, the output of the laser irradiation unit 130, and the operation of the image capture unit 170.

First, the control unit 160 transmits a control signal to the stage unit 110 and controls the stage unit 110 to move the stage unit 110 in at least one of the x-axis direction, the y-axis direction, and the z-axis direction. let it

In addition, the control unit 160 controls the output of the laser irradiation unit 130 so that the laser irradiation unit 130 generates a first laser with any one of 45mW and 55mW or a second laser with any one of 15mW and 30mW. to generate a laser.

In addition, the controller 160 may control on/off of the image capture unit 170 .

The image capturing unit 170 is disposed to face the glass substrate unit 120 and photographs the photocurable resin in real time.

The image capture unit 170 for this may be a CCD camera to which a high magnification lens is attached.

2. Double patterning method of two-photon stereolithography

Hereinafter, a double patterning method of two-photon stereolithography according to an embodiment of the present invention will be described with reference to FIGS. 2 to 8 .

3 is a flowchart illustrating a double patterning method of two-photon stereolithography according to an embodiment of the present invention. 4 is a conceptual diagram illustrating a two-photon stereolithography process using a double patterning device for two-photon stereolithography according to an embodiment of the present invention.

Referring to FIGS. 3 and 4 , the double patterning method of two-photon stereolithography according to an embodiment of the present invention includes (a) preparing the glass substrate 120 on the upper surface of the stage 110 (S100), ( b) a step in which the photocurable resin falls on the upper surface of the glass substrate 120 (S200), (c) a step in which the first laser irradiated from the laser irradiation unit 130 is irradiated with the photocurable resin (S300), (d) The step of primary growth while curing and crosslinking the chemical resin by the first laser (S400), (e) the step of irradiating the primary grown photocurable resin with the second laser irradiated from the laser irradiation unit 130 (S500) , (f) secondarily growing the firstly grown photocurable resin while being cured and crosslinked by a second laser (S600), and (g) 3D printing the three-dimensional structure of the first and secondly grown photocurable resins. It includes a step (S700), and it is characterized in that the deformation of the three-dimensional structure is minimized as the first and second lasers irradiated from the laser irradiation unit 130 having different outputs are irradiated to the photocurable resin.

Here, the photocurable resin may be Su-8, which is an epoxy-based polymer resin.

First, the double patterning device 100 for two-photon stereolithography as shown in FIG. 2 is prepared, and as in step (a) (glass substrate shown in FIG. 4), the glass substrate unit 120 is It is prepared on the upper surface of the stage unit 110.

Next, referring to FIG. 3 , in step (b), the photocurable resin is dropped on the upper surface of the glass substrate part 120 (resin dropping shown in FIG. 4 ).

Next, in step (c), the first laser scans the photocurable resin (laser scanning in FIG. 3).

In this case, in steps (c) and (e), the laser irradiation unit 130 may be a Ti:Sapphire laser having an ultrashort pulse duration of 100 fs or less.

Also, in step (c), the laser irradiation unit 130 generates the first laser with an output of any one of 45mW and 55mW. At this time, the first laser is a laser output with a relatively higher output than the second laser.

FIG. 5 is a diagram illustrating energy distribution and voxel shapes in a laser focus part in a photocurable resin through a double patterning device for two-photon stereolithography according to an embodiment of the present invention.

Next, the step (c) includes: (c1) irradiating the laser focus portion of the photocurable resin to be cured with the first laser, (c2) a region that is locally cured in the laser focus portion irradiated with the first laser Condensing light into a Voxel (Volume of Pixel), (c3) if the control unit 160 does not complete a predetermined process, the stage unit 110 is moved in at least one of the x-axis direction, the y-axis direction, and the z-axis direction and (c4) returning to the step (c1).

Here, before the step (c1), the laser irradiation unit 130 generates the first laser, and the first reflector 141 transmits the first laser emitted from the laser irradiation unit 130 to the second reflector 142. ), the second reflector 142 reflects the first laser reflected by the first reflector 141 to the third reflector 143, and the third reflector 143 reflects the first laser beam reflected by the first reflector 141. 2 including reflecting the first laser reflected by the reflector 142 to the lens unit 150 .

Here, the laser focus part means a part of the photocurable resin to be cured, and has an energy distribution as shown on the left side of FIG. 5 .

The equation for the energy distribution of the laser shown in FIG. 5 is as follows.

As shown in the energy distribution diagram shown on the left side of FIG. 5 and [Equation 1], as the laser energy distribution shows an elongated shape, the shape of the voxel is also formed elongated in the z-axis direction in which it is manufactured.

Next, in the step (c2), the lens unit 150 condenses the first laser reflected by the third reflector 143 into the laser focusing unit so that a voxel (Volume of Pixel), which is a region that is locally cured, is formed. is formed, and the related formula is as follows.

(laser power (P), laser speed (1/t))

At this time, the shape of the voxel is determined by the laser power (P) and laser speed (1/t) reflected in [Equation 2], and other process variables are constant values having constant values during the process.

Next, in the step (c3), when the predetermined process is completed, the step (d) is performed.

Here, the predetermined process means a process up to 3D printing of the first 3D structure according to the shape information included in the 3D CAD file.

For this purpose, the controller 160 controls the movement path, movement distance, movement direction, etc. of the stage unit 110 according to the shape information until the 3D structure is completely 3D printed.

6(a) and (b) are conceptual diagrams showing solvent absorption and shape deformation according to the output of a laser irradiation unit in the double patterning method of two-photon stereolithography according to an embodiment of the present invention.

Next, the step (d) includes (d1) curing the voxel by the first laser, (d2) crosslinking the cured voxel, and (d3) overlapping the crosslinked voxel for primary growth while forming an initial 3D voxel. A step of forming a structure (3D structure by TPP shown in FIG. 4) is included.

In this regard, the laser cross-links the polymer of the photocurable resin. At this time, the degree of curing varies according to the output (P: power) of the laser.

Specifically, when the energy of the irradiated laser is high, cross-linking increases and the distance between polymer-chains decreases.

On the other hand, when the energy of the irradiated laser is low, the cross-linking is small and the gap between the polymer chains is widened.

At this time, the three-dimensional structures (primary and secondary structures) fabricated in the process of developing shown in FIG. 4 absorb the surrounding solvent, and the amount of solvent absorbed according to the spacing of the polymer chains. this will be different

When the polymer-chain interval of the pattern produced by the low laser power is widened, the free-volume in which the surrounding solvent molecules can be absorbed increases and the solvent is well absorbed. Absorption of the solvent causes deformation of the polymer network, and for this reason, shape deformation occurs.

Accordingly, in the present invention, after the steps (c) and (d), the first 3D structure grown by the first laser irradiated with an output of 45mW or 55mW from the laser irradiation unit 130 is 45mW or 55mW. By supplying the second laser irradiated as an output, deformation of the shape of the final 3D structure is minimized.

The method for this is implemented through the detailed steps of step (e) and step (f) below.

In step (e), the laser irradiation unit 130 generates a second laser with an output of either 15mW or 30mw.

In step (e), the laser scanning process shown in FIG. 4 is performed again.

Specifically, the step (e) includes: (e1) re-irradiating the laser focus unit irradiated by the first laser with the second laser; (e2) focusing the second laser on the laser focus unit irradiated by the first laser Reforming a Voxel (Volume of Pixel), (e3) moving the stage in at least one of the x-axis direction, the y-axis direction, and the z-axis direction when the controller 160 does not complete a preset process and (e4) returning to the step (e1).

Steps (e1) to (e4) are performed in the same manner as steps (c1) to (c4). However, the steps (e1) to (e4) are 3D printed by irradiating the second laser again in the same pattern on the same position of the first 3D structure primarily manufactured by the steps (c) to (d). Minimize deformation of dimensional structures (surface peeling, surface bubble defect, burning phenomenon).

Meanwhile, in the step (e3), when the predetermined process is completed, the step (f) is performed.

Next, in step (f), the developing process shown in FIG. 4 is performed again.

Next, the step (f) includes (f1) re-curing the voxel by the second laser, (f2) re-crosslinking the cured voxel, and (f3) overlapping the re-crosslinking voxel for secondary growth. A double patterning method of two-photon stereolithography comprising the step of forming a three-dimensional structure.

Thereafter, in step (g), the first and secondly grown three-dimensional structures of the photocurable resin are 3D printed.

7 (a) and (b) are diagrams comparing the surface peeling phenomenon of a three-dimensional structure manufactured through a double patterning method of two-photon stereolithography according to an embodiment of the present invention and the prior art. 8(a) and (b) are views comparing surface bubble defects and burning phenomena of a 3D structure manufactured through a double patterning method of two-photon stereolithography according to an embodiment of the present invention and the prior art. am.

When a pentagonal film having a side length of 70 μm and a thickness of 5 μm is irradiated with a laser power of 45 mW, a peeling phenomenon is found as shown in FIG. 7(a).

On the other hand, when the same type of structure is manufactured by increasing the laser power to 55 mW to improve the peeling phenomenon, the solvent of the photocurable resin is vaporized by the high-power laser, and bubbles are formed on the surface as shown in FIG. , a phenomenon in which the photocurable resin is burned by the high-power laser.

That is, as in the prior art, a structure 3D printed by irradiating a photocurable resin with a laser only once has a prominent surface peeling phenomenon as shown in FIG. 7 (a), and in FIG. 8 (a) As shown, surface bubble defects and burning phenomena also appear conspicuously.

However, compared to the prior art, the three-dimensional structure 3D printed by the double patterning method of two-photon stereolithography according to an embodiment of the present invention is as shown in FIGS. 7(b) and 8(b). Likewise, surface peeling, surface bubble defects, and burning do not appear.

As described above, the present invention relates to double patterning of two-photon stereolithography for minimizing damage to a resin and peeling of a structure due to high-power laser irradiation, and after single irradiation, the output of the laser irradiated at the same location when single irradiation ( The same pattern is re-irradiated with 15 and 30 mW, which are weaker than 45 mW and 55 mW, respectively, to improve defects such as peeling and shrinkage by increasing cross-linking in the structure and reducing the gap between polymer-chains. can do.

In addition, the present invention improves the bubble phenomenon and burning phenomenon in the structure due to high-power laser irradiation by dividing the laser power and multi-patterning, and reduces damage to the photocurable resin due to high power while increasing cross-linking in the structure. can

The above description of the present invention is for illustrative purposes, and those skilled in the art can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included in the scope of the present invention.

100: double patterning device of two-photon stereolithography
110: stage unit
120: glass substrate part
130: laser irradiation unit
140: reflector
141: first reflector
142: second reflector
143: third reflector
150: lens unit
160: control unit
170: imaging unit

Claims (13)

(a) preparing a glass substrate part on the upper surface of the stage part;
(b) dropping a photocurable resin on the upper surface of the glass substrate;
(c) irradiating the photocurable resin with a first laser irradiated from a laser irradiation unit;
(d) firstly growing the photocurable resin while being cured and crosslinked by the first laser;
(e) irradiating the firstly grown photocurable resin with a second laser irradiated from the laser irradiation unit;
(f) secondarily growing the firstly grown photocurable resin while being cured and crosslinked by the second laser; and
(g) 3D printing the three-dimensional structure of the first and secondly grown photocurable resin;
The double patterning method of two-photon stereolithography, characterized in that the deformation of the three-dimensional structure is minimized as the first and second lasers irradiated from the laser irradiation unit are irradiated to the photocurable resin.
According to claim 1,
In step (c) and step (e),
The double patterning method of two-photon stereolithography, characterized in that the laser irradiation unit is a titanium: sapphire laser having an ultra-short pulse duration of 100 fs or less.
According to claim 1,
In step (c),
(c1) irradiating, with the first laser, a laser focus portion to be cured in the photocurable resin;
(c2) forming a voxel (Volume of Pixel), which is an area where the first laser is focused on the irradiated laser focusing part and is locally cured;
(c3) moving the stage unit in at least one of the x-axis direction, the y-axis direction, and the z-axis direction when a predetermined process is not completed by the control unit; and
(c4) returning to step (c1);
In the step (c3), when the predetermined process is completed, the step (d) is performed.
According to claim 3,
In step (d),
(d1) hardening the voxel by the first laser;
(d2) cross-linking the cured voxel; and
(d3) forming an initial 3D structure by first growing the cross-linked voxels by overlapping them;
According to claim 3,
The double patterning method of two-photon stereolithography, characterized in that the voxel is formed long in the z-axis direction.
According to claim 4,
In step (e),
(e1) re-irradiating, with the second laser, a laser focus portion irradiated by the first laser;
(e2) reshaping the voxel (Volume of Pixel) by concentrating the second laser on a laser focusing part irradiated by the first laser;
(e3) moving the stage unit in at least one of the x-axis direction, the y-axis direction, and the z-axis direction when the predetermined process is not completed by the control unit; and
(e4) returning to step (e1);
In the step (e3), when the predetermined process is completed, the step (f) is performed.
According to claim 6,
In step (f),
(f1) re-hardening the voxel by the second laser;
(f2) re-crosslinking the cured voxels; and
(f3) forming a 3D structure by overlapping the recrosslinked voxels and performing secondary growth.
stage unit;
a glass substrate portion positioned on an upper surface of the stage portion;
a laser irradiation unit positioned on the same straight line as the stage unit to generate a first laser and a second laser;
a first reflector positioned between the stage part and the laser irradiation part to reflect the first and second lasers in an upward direction, and first and second reflectors positioned above the first reflector and reflected by the first reflector; A second reflector that reflects the laser in one direction and a third reflector that is located above the glass substrate portion parallel to the second reflector and reflects the first and second lasers reflected by the second reflector downward. a reflection unit including a unit;
a lens unit disposed between the glass substrate unit and the third reflector and condensing the first and second lasers reflected by the third reflector onto a photocurable resin disposed on an upper surface of the glass substrate unit;
an image photographing unit arranged to face the glass substrate and photographing the photocurable resin in real time; and
A control unit for controlling the operation of the stage unit, the output of the laser irradiation unit, and the operation of the image capture unit;
As the first and second lasers irradiated from the laser irradiation unit are irradiated to the photocurable resin, deformation of the three-dimensional structure is minimized,
The laser irradiator generates the second laser when the photocurable resin is cured and crosslinked by the first laser after generating the first laser,
The double patterning device of two-photon stereolithography, characterized in that the three-dimensional structure is 3D printed by curing and crosslinking the cured and crosslinked photocurable resin again by the second laser.
delete According to claim 8,
The double patterning device of two-photon stereolithography, characterized in that the laser irradiation unit is a titanium: sapphire laser having an ultra-short pulse duration of 100 fs or less.
According to claim 8,
Wherein the control unit moves the stage unit in at least one of an x-axis direction, a y-axis direction, and a z-axis direction when a predetermined process is not completed.
According to claim 8,
The double patterning device of two-photon stereolithography, characterized in that the laser irradiation unit irradiates the first laser to the photocurable resin.
According to claim 8,
The double patterning device of two-photon stereolithography, characterized in that the laser irradiation unit irradiates the second laser to the photocurable resin that is primarily grown while being cured and crosslinked by the first laser.

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