KR20100033781A - Lens with micro-patterned complex surface and making method of the same - Google Patents

Abstract

PURPOSE: A lens with a micro-patterned complex surface and a making method of the same are provided to distribute the light from a light source widely and uniformly. CONSTITUTION: A template is formed by patterning a fine complex pattern on a substrate(1). A thin film layer(3) covers the fine complex pattern(2). The thin film layer which is made of material having elasticity is formed on the template. The thin film layer and template are separated from each other after attaching the thin film layer to an opening of a chamber. The chamber is concaved inward when receiving a negative pressure.

Description

Lens with Micro-Patterned Complex Surface and Making Method of the same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a micro composite lens and a micro composite lens, and more particularly, to a method for manufacturing a micro composite lens and a micro composite lens for dispersing light from a light source broadly and uniformly.

Currently, many techniques for controlling light through lens surface deformation using a sophisticated MEMS (MicroElectroMechanical System) process in the micro area are being developed. Among them, the research which spreads light evenly and widely is attracting much attention recently.

In particular, as many advantages of Light Emitting Diodes (LED) BLUs are revealed over Backlight Units (BLUs) used in existing LCD-TVs, LED BLUs are being actively applied to the LCD-TV market.

In the case of LED light sources for LCD and lighting BLUs, the role of lenses is increasing due to the importance of light diffusion. However, domestic LED companies have been procuring lenses through imports from Europe or Japan or jointly developed with overseas companies. In order to drive the growth of the LED industry, it is urgent to develop domestic lens technology. Technological weight is very high, such as brightness depends on lens according to LED. Currently, lens accounts for less than 5% of total LED production price, but it is expected to be slightly higher for high-power LED. Especially in the case of LCD BLU applications, the role of the lens is very important. In view of achieving low cost by reducing the number of LEDs while maintaining a thin thickness, development of a lens having a wide light emission angle is required.

Conventionally, the lens installed on the LED is capable of improving the emission angle, but there is a limit in controlling the light uniformity, and when converting a point light source such as an LED into a surface light source, various complex optical elements such as a separate light guide plate, prism plate, and diffusion plate There was a problem that a substrate is required. Since the manufacturing process cost of each element is high, and precise packaging is required, there is a limit in reducing the overall production cost, so an integrated optical device is required.

The present invention has been made to solve the above-mentioned problems of the prior art, a micro-composite lens and a method of manufacturing a micro-composite lens to form a larger light emission angle by forming a micro-composite pattern of various forms on the surface of the lens The purpose is to provide.

In the micro-composite lens according to the present invention for solving the above problems is formed a micro-composite pattern in which one or more protrusions having a circular or polygonal cross section is formed on one surface of the lens having a predetermined curvature, the photopolymer nano Particles.

Here, the microcomposite lens is formed of at least one of an ultraviolet curing polymer, a thermosetting polymer, and a ceramic.

In addition, the surface curvature of the lens on which the protrusion is formed may have a convex edge, and may be concave toward the center of the lens.

The horizontal cross section of the protrusion has a shape of one of a circle, a square, a triangle, a hexagon, and a rhombus.

The microcomposite lens has a microcomposite pattern in which cross-sections of the protrusions having one or more shapes of circle, quadrangle, triangle, hexagon, and rhombus are arranged in a complex manner.

The vertical cross section of the protrusion has one shape of a rectangle, a semicircle and a triangle.

The protrusion has a shape of at least one of a cylinder, a hemisphere, a cone, a square pillar, a square pyramid, a triangular prism, a triangular pyramid, a hexagonal pillar, and a hexagonal pyramid.

The height or width of the protrusion may have a variety of wavelengths or more of the light source to be irradiated for uniformity control of the light.

In this case, the protrusion of the lens may be formed to have a hemispherical protrusion in order to increase a large light emission angle and light uniformity.

The lens thickness at the point 1/2 from the center of the micro composite lens to the edge may be formed to be larger than the thickness at the center.

The micro-composite lens may have an anti-reflective layer having an ultra fine pattern having a smaller size than the protrusion between the protrusion and the protrusion or on the protrusion.

Method for manufacturing a micro composite lens according to the present invention for solving the above problems is a method of manufacturing a micro composite lens having a micro-composite pattern is formed on one surface of the lens having a predetermined curvature, the one or more projections having a circular or polygonal cross section is arranged A first step of fabricating a template by patterning the microcomposite pattern on a substrate, a second step of forming a thin film layer of a material having elasticity on the template to cover the microcomposite pattern, the thin film layer of the chamber A third step of separating the thin film layer and the template after adhering to the opening, a fourth step of applying a negative pressure to the chamber so that the thin film layer is recessed into the chamber, and the photopolymer nanoparticles on the concave surface of the thin film layer The fifth step of forming a lens by filling the filler containing the and from the thin film layer And a sixth step of separating.

Here, the thin film layer is formed of polydimethylsiloxane (PDMS).

The substrate is a silicon or glass substrate.

In the second step, the thickness of the thin film layer is greater than the height of the microcomposite pattern.

The third step further performs an oxygen plasma treatment of the thin film layer before adhering the thin film layer to the chamber.

The thin film layer from which the template is removed in the third step has a pattern structure complementary to the microcomposite pattern.

The fourth step is to discharge the air in the chamber through the microfluidic channel formed in the chamber to apply a negative pressure.

The fifth step includes a first process of filling at least one filler of an ultraviolet curable polymer, a thermosetting polymer, and a ceramic on a concave surface of the thin film layer, and a second process of curing the filler by applying ultraviolet light or heat to the filler. It is done by

In the method of manufacturing a micro composite lens and a micro composite lens according to the present invention configured as described above, a larger light emission angle can be formed by a micro composite pattern, thereby converting an LED light source, which is a point light source, into a surface light source having excellent light uniformity. This is possible. In addition, there is an advantage that a single lens can replace the role of the light guide plate, prism plate, and diffuser plate without the composite lamination of the optical substrate used in the conventional backlight unit.

In addition, it is possible to increase the emission angle of the LED light source close to 90 degrees more than 160 degrees, and to improve the uniformity of the light quantity through the local change of the fine pattern, and based on the three-dimensional molding technology and the ultra fine particle mixing technology This enables wafer-level fabrication using microfluidic tube arrays.

In addition, the number of LEDs can be reduced through a single lens having a wide light emission angle, thereby reducing manufacturing costs and reducing heat generated from the LEDs.

Hereinafter, with reference to the accompanying drawings will be described specific details and embodiments of the present invention.

1 is a cross-sectional view showing the structure of a micro composite lens according to the present invention.

Referring to FIG. 1, in the micro-composite lens according to the present invention, a micro-composite pattern including a plurality of protrusions 10 is formed on a surface of the lens 100, and the material constituting the lens 100 is a photopolymer nano. It includes particles, the light passing through the inside of the lens is reflected and diffracted by the nanoparticles 20 and the protrusion 10 so that the light is wide and evenly emitted to the outside of the lens.

The microcomposite lens may be made of a material such as UV curable epoxy resin, thermosetting polymer, or ceramic, which is a photosensitive polymer.

2 is a diagram illustrating embodiments of a micro composite pattern of a micro composite lens according to the present invention.

2, the horizontal cross section of the protrusion of the microcomposite pattern may be configured in the form of (a) circle (b) square (c) triangle (d) hexagon (e) rhombus.

The protrusions having the above shapes are continuously arranged to form a fine composite pattern.

In this case, the vertical cross section of the protrusion may be formed in the shape of a rectangle, a semicircle, a triangle, or the like.

In this case, the three-dimensional shape of the protrusion may be represented by a cylinder, hemisphere, cone, square pillar, square pyramid, triangular prism, triangular pyramid, and the like.

Here, the height or width of the protrusion has a variety of wavelengths or more of the light source to be irradiated for uniformity control of the light. In order to increase diffraction efficiency, the width of the protrusion is preferably equal to or greater than the wavelength of the light source.

In the present invention, the present invention is not limited to the above-described form, and protrusions of various forms may be formed on the lens surface.

In addition, the shape of the micro-composite lens is not limited to the convex lens or the concave lens, and may be manufactured in various forms, and the shape or size of the protruding portion may also be complexly arranged to form the micro-composite pattern.

3 and 4 illustrate embodiments of the present invention in various forms.

3 is a diagram showing a first embodiment of the micro composite lens according to the present invention.

FIG. 3A is a view showing the top view of the lens, and FIG. 3B is a cross-sectional view of the lens in a vertical direction.

A plurality of protrusions 10 are formed in a pattern on the surface of the lens 100.

Herein, the surface curvature of the lens 100 having the protruding portion is not limited to the convex lens or the concave lens, and is manufactured in various forms, and in one embodiment, the edge is convex, and concave toward the center of the lens. Can be.

That is, when the above embodiment is described in detail, the thickness H1 of the center portion A of the lens is half the thickness H2 of the distance from the center portion A of the lens to the edge C of the lens. It is formed smaller.

4 is a diagram showing a second embodiment of the micro composite lens according to the present invention.

4 (a) is a diagram showing a state in which the micro-composite pattern formed on the lens surface is projected on the horizontal line, (b) is a cross-sectional view showing a vertical cross section of the micro-composite lens.

Referring to FIG. 4, in the second embodiment of the micro composite lens according to the present invention, a cylindrical protrusion 10a is formed on a surface near the center of the lens, and a hemispherical protrusion 10b is formed toward the edge of the lens. Is formed.

That is, the two shape protrusions are formed to form a pattern in combination.

In addition, the shape of the protrusions is also configured such that the two types of protrusions different from each other.

The height of the protrusion 10a is formed higher than the height of the protrusion 10b.

The above description is just one embodiment, and in the present invention, the protrusions of various shapes may be arranged in a complex manner to form a microcomposite pattern.

5 is a view showing a third embodiment of the micro composite lens according to the present invention.

Referring to FIG. 5, the third embodiment of the micro composite lens according to the present invention has a height ratio with respect to the width of the protrusion 10 between the protrusions 10 of the micro composite pattern formed on the surface of the lens 100. It is configured to form the anti-reflective layer 30 of the ultra fine pattern having a larger height ratio.

가 되는 것이 바람직하다. 여기서 n 은 0, 1, 2... 이다.Here, the width of each one of the ultrafine patterns is preferably less than the wavelength λ of the light source to be irradiated, and the height of the ultrafine pattern is

It is preferable to become. Where n is 0, 1, 2 ...

In this case, the antireflective layer 30 may be formed on the protrusion of the microcomposite pattern.

Another embodiment of the anti-reflective layer is composed of a micro thin film layer covering the protrusion and the lens surface instead of the ultra fine pattern. In this case, the antireflective layer may be formed of one or more micro thin layers.

Here, one example of the thickness of the anti-reflective layer is 1/4 of the light source wavelength, has a refractive index smaller than that of the lens, and includes a material including one or more of MgF ₂ , Al ₂ O ₃ , ZrO ₂ , and parylene. Is formed. The optimum refractive index of the antireflective layer is the square root of the refractive index of the lens.

The antireflective layer 30 minimizes back reflection in the direction of the LED light source due to multiple reflections.

6 is a view illustrating a comparison of light transmission between a general microlens and a micro composite lens according to the present invention.

6 (a) is a case of a general microlens, in the case of a general microlens, the light passing through the lens is collected at the center of the lens, whereas as shown in FIG. In the case of the diffraction is performed at various angles by the protrusion to form a larger light emission angle than the general microlens.

Referring to Figure 6 (c), the micro-composite lens according to the present invention is the main curvature (P1) of the lens and the refractive index (P2) of the lens material, the shape, size, period, aspect ratio of the protrusions 10, etc. To adjust the maximum light emission angle.

7 is a photograph of a light distribution of a general microlens and a microcomposite image lens according to the present invention when a white light source is incident.

FIG. 7A is a light distribution image of a general microlens having a convex curved surface, and FIG. 7B is a light distribution image of a microcomposite lens having a microcomposite pattern formed on a convex curved surface.

It can be seen that the light distribution is wider and more uniformly distributed in the case of the micro composite lens according to the present invention than in the case of the general micro lens. In this case, the maximum intensity of the light is reduced by the diffraction pattern caused by the micro-composite pattern, but it can be seen that the uniformity of light passing through the lens as a whole is improved.

8 is a photograph of light intensity distribution of a general microlens and a micro composite lens according to the present invention.

In the case of the general microlenses, it can be seen that the light intensity distribution of the micro composite lens according to the present invention is more uniform than that of the LED light source.

9A and 9B are views illustrating a comparison of light distribution and progress of a white light source after passing through a white light source in the case of a general microlens in a dome form and in the case of a microcomposite lens according to the present invention.

9a (a) is a view showing a general white light source to go straight, and (b) is a picture of the light passing through the general microlens, the light passing through the lens is seen to scatter again scattered again. In the case of (c), the light distribution is photographed from the front of the lens, and the light is collected without spreading widely.

In case of (a) of FIG. 9B, the light passing through the diffraction grating is shown. In the case of (b), light passing through the micro-composite lens is photographed from the side. It can be seen that it spreads. In the case of (c), it can be seen that the light is evenly distributed according to the microcomposite pattern formed on the lens surface.

10 is a photograph showing a state in which the micro composite lens according to the present invention is photographed through a scanning electron microscope (SEM).

Figure 10 (a) is a photograph of the surface of the micro-composite lens through a scanning electron microscope (Scanning Electron Microscope, SEM), it can be seen that very minute protrusions form a pattern, (b) is further enlarged It can be seen that the protrusion has a micropillar shape, and the distance between the protrusion and the protrusion is about 3 μm.

FIG. 11 is a graph showing the intensity of light according to the complex condition of the gap between the protrusions, the width of the protrusions, and the width and the gap of the micro composite lens according to the present invention.

In the case of (a), the distance between the protrusions and the protrusions is gradually increased while the size of the protrusions is the same. In this case, as the distance between the protrusions decreases, the light emission angle increases and the light intensity decreases.

In the case of (b), the width of the protrusions is increased while the spacing between the protrusions is the same. In this case, as the width of the protrusions decreases, the light emission angle increases and the light intensity decreases.

In the case of (c), all the gaps and the widths of the protrusions are compared, and as the width and the gap of the protrusions are narrower, the light emission angle increases and the light intensity decreases.

In all three cases, in the case of the general dome-type microlenses, the light intensity is strong and the light emission angle is small, so that the uniformity is low.

12 is a view illustrating a manufacturing process illustrating a method of manufacturing a micro composite lens according to the present invention.

In the method of manufacturing a micro-composite lens according to the present invention, a template is first manufactured by patterning the micro-composite pattern 2 on the substrate 1 as shown in (a). Here, the substrate 1 may be a glass substrate.

Next, as shown in (b), the thin film layer 3 is formed of a material having elasticity on the template to cover the microcomposite pattern 2. In this case, the thin film layer 3 may generally be a polymer material having elasticity such as a synthetic resin. For example, the thin film layer 3 may be formed of polydimethylsiloxane (PDMS).

Here, the thickness of the thin film layer 3 is larger than the height of the microcomposite pattern 2 so as to completely cover the microcomposite pattern 2.

Next, as shown in (c), the thin film layer 3 is bonded to the opening of the chamber 200.

In this case, before the thin film layer is adhered to the chamber, the thin film layer may be subjected to an oxygen plasma treatment to remove foreign substances.

Here, the chamber 200 has an empty space 210 formed therein, and one surface of the chamber is formed with a microfluidic channel 220 connected to the empty space therein.

Thereafter, the thin film layer 3 and the templates 1 and 2 are separated.

Here, the thin film layer from which the template is removed has a pattern structure complementary to the microcomposite pattern.

Next, as shown in (d), a negative pressure is applied through the microfluidic channel 220 so that the thin film layer 3 is recessed into the chamber. Here, applying the negative pressure means that the air pressure inside the chamber is lower than the outside of the chamber, and the air inside is discharged to the outside of the chamber.

Next, as shown in (e), the filler 100 containing the photopolymer nanoparticles is filled on one concave surface of the thin film layer 3, covered with the substrate 300 thereon, and then the ultraviolet light or heat is applied to the filler. Harden (100).

Here, the filler may be an ultraviolet curing polymer, a thermosetting polymer and a ceramic.

When the filler 100 is cured, this becomes the microcomposite lens of the present invention, which is separated from the thin film layer as shown in (f).

Thereafter, a micro thin film layer, which is an antireflective layer, may be formed on the lens surface as necessary. In addition, the anti-reflective layer may be formed through a process of filling the filler 100 after forming and curing the thin film on the thin film layer 3 before filling the filler 100.

The master used for molding the lens in the lens manufacturing process of the present invention as described above is made of the original modified lens master using a silicon-based PDMS excellent in deformation, and then replicated using an ultraviolet curable resin or a thermosetting resin and then back to the PDMS. Reproduction makes it possible to manufacture fixed masters from deforming masters.

In addition, the lens manufacturing method according to the present invention can be designed to have the same deformation under the same pressure at the same time by connecting the deformation lens master through the microfluidic tube as shown in Figure 13 in the fine molding technology, based on this Wafer level processing can be achieved.

As described above, the method for manufacturing the micro-composite lens and the micro-composite lens according to the present invention has been described with reference to the illustrated drawings. It can be applied within the range.

1 is a cross-sectional view showing the structure of a micro composite lens according to the present invention;

2 is a view showing embodiments of a micro composite pattern of a micro composite lens according to the present invention;

3 is a view showing a first embodiment of the micro composite lens according to the present invention;

4 is a view showing a second embodiment of the micro composite lens according to the present invention;

5 is a view showing a third embodiment of the micro composite lens according to the present invention;

6 is a view illustrating a comparison of light transmission between a general microlens and a micro composite lens according to the present invention;

7 is a photograph of a light distribution of a general microlens and a micro composite lens according to the present invention when a white light source is incident;

8 is a photograph of a light intensity distribution of a general microlens and a micro composite lens according to the present invention;

FIG. 9A is a diagram illustrating a light movement path of a general microlens in the form of a light source and a dome and a distribution of light passing through the general microlens in the form of a dome;

FIG. 9B is a view showing the light movement paths of the diffuser plate and the dome-shaped microcomposite lens and the distribution of light passing through the dome-shaped microcomposite lens. FIG.

FIG. 10 is a photograph showing a state of photographing a micro composite lens according to the present invention through a scanning electron microscope (SEM);

11 is a graph showing the intensity of light according to the complex condition of the interval between the protrusions, the width of the protrusions, the width and the interval of the micro-composite lens according to the present invention,

12 is a view illustrating a manufacturing process for explaining a method for manufacturing a micro composite lens according to the present invention;

13 is a view showing a device that can make several micro-composite lenses in accordance with the present invention at the same time.

<Explanation of symbols on main parts of the drawings>

1: substrate

2: fine composite pattern

3: thin film layer

10: protrusion

20: nanoparticles

100: lens

200: chamber

Claims (20)

The microcomposite lens of claim 1, wherein a microcomposite pattern having one or more protrusions having a circular or polygonal cross section is formed on one surface of the lens having a predetermined curvature, and including photopolymer nanoparticles inside the lens. The method according to claim 1, The microcomposite lens is a microcomposite lens, characterized in that formed of at least one of an ultraviolet curing polymer, a thermosetting polymer and a ceramic. The method according to claim 1, The surface of the lens on which the protrusion is formed is a convex edge is formed, the micro composite lens characterized in that the concave toward the center of the lens. The method according to claim 1, The horizontal cross section of the protrusion has a shape of one of a circle, a quadrangle, a triangle, a hexagon, and a rhombus. The method according to claim 1, The micro-composite lens is a micro-composite lens, characterized in that the micro-composite pattern is formed in which the protrusions having a cross-section of two or more of the shape of a circle, square, triangle, hexagon, rhombus are arranged in combination. The method according to claim 1, The vertical cross section of the protrusion has a shape of one of a quadrangle, a semi-circle and a triangle. The method according to claim 1, The protrusion has a shape of at least one of a cylinder, a hemisphere, a cone, a square pillar, a square pyramid, a triangular prism, a triangular pyramid, a hexagonal pillar, and a hexagonal pyramid. The method according to claim 1, The protrusion has a width of more than the wavelength of the light source to irradiate the micro-composite lens. The method according to claim 1, The protrusion has a hemispherical shape at the edge of the lens in order to increase the light emission angle and light uniformity. The method according to claim 1, And the lens thickness at the point 1/2 from the center of the micro composite lens to the edge is larger than the thickness at the center. The method according to claim 1, The micro composite lens further comprises an antireflection layer having an ultra fine pattern formed between the protrusion and the protrusion or smaller than the protrusion on the protrusion. The method according to claim 1, The microcomposite lens further comprises an antireflection layer comprising at least one micro thin film layer formed to cover the protrusion and the lens surface. In the method of manufacturing a micro-composite lens having a microcomposite pattern in which at least one protrusion having a circular or polygonal cross section is arranged on one surface of a lens having a predetermined curvature, A first step of manufacturing a template by patterning the microcomposite pattern on a substrate; Forming a thin film layer of an elastic material on the template to cover the microcomposite pattern; Attaching the thin film layer to the opening of the chamber and separating the thin film layer from the template; A fourth step of applying a negative pressure to the chamber so that the thin film layer is recessed into the chamber; A fifth step of forming a lens by filling a filler including photopolymer nanoparticles on one concave surface of the thin film layer; And a sixth step of separating the lens from the thin film layer. 14. The method of claim 13, The thin film layer is a micro-composite lens manufacturing method characterized in that formed of polydimethylsiloxane (PDMS). 14. The method of claim 13, And said substrate is a glass substrate. 14. The method of claim 13, The method of claim 2, wherein the thickness of the thin film layer is greater than the height of the microcomposite pattern. 14. The method of claim 13, The third step is a method of manufacturing a micro composite lens, characterized in that further performing the process of oxygen plasma treatment of the thin film layer before adhering the thin film layer to the chamber. 14. The method of claim 13, The thin film layer from which the template is removed in the third step has a pattern structure complementary to the microcomposite pattern. 14. The method of claim 13, The fourth step is a method for manufacturing a micro composite lens, characterized in that for applying a negative pressure by discharging the air in the chamber through the microfluidic channel formed in the chamber. 14. The method of claim 13, The fifth step may include a first process of filling at least one filler of an ultraviolet curable polymer, a thermosetting polymer, and a ceramic on a concave surface of the thin film layer; And And a second step of curing the filler by applying ultraviolet rays or heat to the filler.

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