KR20130071837A - High numerical aperture lens for using fluoro-polymer thin film coating and manufacturing method thereof - Google Patents

Abstract

PURPOSE: A high numerical aperture lens using fluorine polymer thin film coating and a manufacturing method thereof are provided to have the advantage of making an excellent high numerical aperture lens with a large area by using a simple making method when a micro lens is formed by using thermal reflow. CONSTITUTION: A manufacturing method of high numerical aperture lens using fluorine polymer thin film coating comprises the following steps of: the step of forming at least one cylindrical shape pattern on a substrate which consists of one among glass, photoresist, polymer, silicone, and a III-V semiconductor material; the step of coating a fluorine polymer thin film on the upper part of the cylindrical-shaped pattern of a cylinder and on the surface of a substrate; and the step of forming a micro lens by performing heat treatment on the pattern which is coated with the fluorine polymer thin film. The lateral cross section of the cylindrical shape pattern has one among a circle, a square, and a hexagon. [Reference numerals] (AA) Start; (BB) End; (S10) Form a cylindrical pattern on a substrate; (S20) Coat a fluorine polymer thin film on the upper part of the cylindrical pattern and on the surface of the substrate; (S30) Perform heat treatment on the coated pattern; (S40) Form a micro-lens

Description

HIGH NUMERICAL APERTURE LENS FOR USING FLUORO-POLYMER THIN FILM COATING AND MANUFACTURING METHOD THEREOF}

The present invention relates to a high-aperture lens and a method of manufacturing the same, and more particularly, by using a fluoropolymer thin film coating that can increase the numerical aperture of the lens by forming a hydrophobic film by coating a fluoropolymer thin film when manufacturing the lens. The present invention relates to a high aperture lens and a method of manufacturing the same.

In general, micro lenses (microlenses) are commonly used in optical communications, medical devices, and optical devices, including connections between optical devices such as optical fibers, planar lightwave circuits (PLC), laser diodes (LD) Sensors, optoelectronic devices, and the like.

It is also possible to increase the light receiving efficiency of the image sensor or increase the light emitting efficiency of the display by using the light receiving and light emitting characteristics of the fine lens.

Recently, in a method of manufacturing a fine lens, a fine lens is manufactured using a thermal reflow method based on the thermoplastic properties of a polymer material. Such a thermal reflow method is advantageous in that it is easy to control the shape of the lens, has efficiency in terms of mass production and precision processing, facilitates the integration of fine lenses, and shortens the manufacturing process steps of the lens.

In connection with the fabrication of such a fine lens, Korean Patent Laid-Open Publication No. 206-0017172 relates to a self-aligning image sensor and a method of manufacturing the same, and includes forming a color filter resist on a substrate and reflowing the formed color filter resist. To form a microlens is disclosed.

In addition, Korean Patent Publication No. 205-0005357 relates to a method for fabricating a microlens and an optical module using the same. A thin film is formed on a substrate, and a photoresist pattern is formed on the thin film. A method of forming a microlens by reflowing by heat-treating the thin film structure is disclosed.

However, in the related art, when reflowing a resist or a thin film structure formed on a substrate, the contact angle between the end point of the curve of the microlens formed by the wetting condition of the substrate and the surface of the substrate becomes small, which is good. There is a limit to obtaining the characteristics of a high aperture lens.

The present invention has been made to solve the above problems, by coating a fluorine polymer on a substrate formed with a cylindrical cylindrical photoresist pattern to impart hydrophobicity, by forming a fine lens using thermal reflow, An object of the present invention is to provide a high-aperture lens using a fluoropolymer coating and a method for manufacturing the same, which are simple in manufacturing method and capable of producing a good high-aperture lens having a large area.

In addition, the present invention provides a high-aperture lens using a fluoropolymer coating and a method for manufacturing the same, which can produce a high-resolution lens having a high resolution characteristics by increasing the contact angle between the curved end of the fine lens formed on the substrate and the surface of the substrate. The purpose.

However, the object of the present invention is not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, a method of manufacturing a high numerical aperture lens using a fluoropolymer coating according to the present invention comprises the steps of forming at least one cylindrical cylindrical pattern on the substrate; Coating a fluoropolymer thin film on an upper portion of the cylindrical pattern of the cylinder and a surface of the substrate; And forming a fine lens by performing a heat treatment process on the pattern coated with the fluoropolymer thin film.

The high-molecular-number lens manufacturing method using the fluoropolymer coating according to the present invention is characterized in that the cross section in the horizontal direction of the cylindrical pattern has one of a circle, a square, and a hexagon.

According to the present invention, a method for manufacturing a high-aperture lens using a fluoropolymer coating may include the fluorine polymer thin film, C3F8, C4F8, CHF3, vinyl fluoride, vinylidene fluoride, and tetrafluoroethylene. Perfluoropropylvinylether (Perfluoropropylvinylether), perfluoromethylvinylether (Perfluoromethylvinylether), chlorotrifluoroethylene (Chlorotrifluoroethylene) is characterized in that any one selected from the group consisting of.

According to the present invention, a method for manufacturing a high-aperture lens using a fluoropolymer coating is characterized in that in the step of coating the fluoropolymer thin film, the fluoropolymer coated on the pattern top and the substrate surface is coated in a vacuum or air.

In the method of manufacturing a high-aperture lens using a fluoropolymer coating according to the present invention, in the step of performing the heat treatment process, the pattern is characterized in that the heat treatment process is performed in vacuum or air.

The method for producing a high-aperture lens using a fluoropolymer coating according to the present invention is characterized in that the heat treatment process for the pattern uses conduction or convection.

The method for producing a high-numbered lens using a fluoropolymer coating according to the present invention is characterized in that the microlenses formed by performing the heat treatment process have a spherical or aspherical shape.

According to the present invention, a method for manufacturing a high-aperture lens using a fluoropolymer coating is characterized in that the cylindrical cylindrical pattern is made of any one of a photoresist or a polymer.

The high-numbered lens manufacturing method using the fluoropolymer coating according to the present invention is characterized in that the ratio of the diameter to the height of the fine lens is at least 0.4.

In the method of manufacturing a high-aperture lens using a fluoropolymer coating according to the present invention, the numerical aperture of the microlens is at least 0.25.

A high-aperture lens using a fluoropolymer coating according to the present invention includes a substrate made of glass, photo resist, polymer, silicon or a semiconductor material; At least one microscopic lens formed on the substrate; And a fluoropolymer thin film coated on a surface of the micro lens and a surface of the substrate.

The high-aperture lens using the fluoropolymer coating according to the present invention is characterized in that the microlenses are formed through a heat treatment process after forming a cylindrical cylindrical pattern on the substrate.

According to the high-numbered lens using the fluoropolymer coating of the present invention and a manufacturing method thereof, by applying a fluoropolymer to the substrate formed with a cylindrical cylindrical photoresist pattern to impart hydrophobicity, a fine lens using thermal reflow There is an advantage that can be produced a good high-numbered lens of a large area by a simple manufacturing method at the time of formation.

In addition, according to the present invention, by increasing the contact angle between the end point of the curve of the fine lens formed on the substrate and the surface of the substrate, there is an advantage that a high-aperture lens having high resolution characteristics can be manufactured.

In addition, according to the high aperture lens using the fluoropolymer coating of the present invention, there is an advantage that can be applied to a variety of projection lithography, imaging lens or lens for the image sensor.

FIGS. 1A and 1B are views illustrating the fabrication of a fine lens using thermal reflow.
Figs. 2A and 2B are exemplary views of a micrograph showing a large-area micro-lens array by the thermal reflow process of Figs. 1A and 1B.
3A and 3B are exemplary views illustrating optical property control of a microlens using thermal reflow.
4 (a) and 4 (b) are exemplary views of micrographs for showing hydrophobic properties of a substrate according to fluoropolymer thin film coating.
FIG. 5 is a graph showing hydrophobic characteristics of the substrate according to the fluoropolymer thin film coatings of FIGS. 4A and 4B.
6 is a flowchart illustrating a method of manufacturing a high-aperture lens using a fluoropolymer thin film coating according to an embodiment of the present invention.
7A to 7C are exemplary views illustrating fabrication of a high-aperture lens using a fluoropolymer thin film coating according to an embodiment of the present invention.
8A and 8B are exemplary views showing a high-aperture lens using a fluoropolymer thin film coating according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description of preferred embodiments of the present invention will be given with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Embodiments in accordance with the concepts of the present invention can make various changes and have various forms, so that specific embodiments are illustrated in the drawings and described in detail in this specification or application. However, this is not intended to limit the embodiments in accordance with the concept of the present invention to a particular disclosed form, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, the terms "comprises ",or" having ", or the like, specify that there is a stated feature, number, step, operation, , Steps, operations, components, parts, or combinations thereof, as a matter of principle.

1A and 1B are exemplary views illustrating the fabrication of a microlens using thermal reflow, and FIG. 2 is an exemplary view showing a large area microlens array by the thermal reflow of FIGS. 1A and 1B, and FIGS. 3A and 1B. 3b is an exemplary diagram showing optical property control of the fine lens using thermal reflow.

As shown in FIGS. 1A and 2A, a cylindrical cylindrical pattern 200 is formed on the substrate 100. In this case, the substrate 100 may be made of glass, a photo resist, a polymer, a silicon, or a III-V semiconductor material. In addition, the cylindrical cylindrical pattern 200 is a photoresist or a polymer (pattern) pattern has a variety of shapes, such as a circle, a square, a hexagon, the cross section, and can be generally formed through a semiconductor etching or photolithography process.

When the high temperature reflow, that is, the heat treatment 400 is performed on the substrate 100 on which the pattern 200 is formed as described above, in particular, the substrate 200 is heated to a temperature higher than the glass transition temperature (Tg) of the photoresist or polymer. 1B and 2B, as the surface area of the polymer is reduced, a spherical microlens 300 is formed.

In the high temperature heat treatment process, the mass decreases as the solvent contained in the pattern is vaporized, but the amount of change is extremely small, so that the cylindrical cylindrical pattern 200 has a cylindrical cylindrical pattern (as shown in FIG. 3A). 200 and the volume of the spherical fine lens 300 is almost the same. Accordingly, the diameter D _C of the cylindrical cylindrical pattern 200 is the same as the diameter D _{L of the} microlens 300, and the final height t _L of the lens 300 is the cylindrical cylindrical pattern ( It is 1.1 1.7 times the height (t _C ) of the 200).

In addition, the optical characteristics of the fine lens 300 formed through the heat treatment process, as shown in Figure 3b, the radius of curvature (radius of curvature) (R) is obtained through the following equation (1).

[Formula 1]

Here, K is an aspherical constant (aspherical constant) has a value of 0 when the microlens 300 is spherical, elliptic (1 <K <0 or K> 0) in the case of aspherical, parabolic (K = 1 ), hyperbolic may have a value of (K <1). H _L is the thickness of the lens, and r is the radius of the lens.

Focal length f through Equation 1 can be obtained through Equation 2 below.

[Formula 2]

Here, n represents a refractive index and? Represents a wavelength.

The numerical aperture (NA) of the lens can be obtained from Equation 3 below.

[Equation 3]

Here, F means the F-number of the lens, and is the value obtained by dividing the effective diameter of the lens by the effective focal length of the lens as shown in the equation. If F-number is small, the image becomes brighter and the theoretical spatial resolution It gets better.

As can be seen from the above equation, when the thickness of the pattern, that is, the thickness h _L of the lens is increased, the radius of curvature R becomes smaller and the focal length f becomes smaller, do. Therefore, the resolution of the fine lens 300 can be increased.

Figure 4 (a) and (b) is an illustration of a micrograph to show the hydrophobic characteristics of the substrate according to the fluoropolymer thin film coating, Figure 5 is a fluoropolymer thin film coating of Figures 4 (a) and (b) Is a graph showing the hydrophobicity of the substrate.

Generally, the contact angle ([theta]) is a measure of the wetting property of a solid, and can be measured through water droplets adhering to the substrate. This contact angle can be measured from the point of contact between the end point of the water droplet curve and the solid surface at the junction of the liquid-solid-gas. Also, depending on whether the surface of the substrate is hydrophobic or hydrophilic, the shape of water droplets adhering to the substrate is changed.

As shown in FIG. 4A, the water droplets spread on the general silicon substrate. On the other hand, as shown in Figure 4b, the silicon substrate coated with a fluoropolymer thin film has a hydrophobic characteristic, so that the water droplets appear round and the contact angle θ is also larger than the droplet of Figure 4a.

FIG. 5 is a graph showing hydrophobicity, ie, contact angle, of a silicon substrate coated with a fluoropolymer, for example, a C4F8 thin film and a glass substrate. In the graph of FIG. 5, the vertical axis represents the contact angle and the horizontal axis represents the number of treatments of the fluoropolymer thin film.

As shown in the graph of FIG. 5, by coating the fluoropolymer thin film on the silicon substrate and the glass substrate in the same manner, the contact angle θ has a value between 100 and 120 degrees, and in particular, has almost the same contact angle regardless of the substrate. It can be seen that.

Detailed description of the high-aperture lens and the manufacturing method using a fluoropolymer coating according to the present invention will be described in detail with reference to FIGS.

[Example]

FIG. 6 is a flowchart illustrating a method of manufacturing a high-aperture lens using a fluoropolymer thin film coating according to an embodiment of the present invention, and FIGS. 7A to 7C are views of a high-aperture lens using a fluoropolymer thin film coating according to an embodiment of the present invention. It is an exemplary figure which shows production.

As shown, a plurality of patterns (e.g., a plurality of patterns on the substrate 10, for example, glass, a photo resist, a polymer, a silicon, or a III-V semiconductor material) may be used. 20) For example, a cylindrical cylindrical pattern is formed (S10).

At this time, the pattern 20 to be formed is made of, for example, a photoresist or a polymer and can be formed through a general semiconductor etching or photolithography process. In addition, the cylindrical cylindrical pattern formed on the substrate 10 may have various shapes such as a circle, a square, a hexagon, and the like in a horizontal cross section.

Then, a fluoropolymer thin film 40 is coated on the upper surface of the pattern 20 and the surface of the substrate 10 (S20).

The fluoropolymer thin film 40 may be formed of a material selected from the group consisting of C3F8, C4F8, CHF3, vinyl fluoride (VF1), vinylidene fluoride (VDF or VF2), tetrafluoroethylene (TFE), perfluoropropyl vinyl ether And may be formed using various precursors such as perfluoropropyl vinyl ether (PPVE), perfluoromethyl vinyl ether (PMVE), and chlorotrifluoroethylene (CTFE).

Next, a micro-lens 30 coated with the fluoropolymer thin film 40 is formed by performing a heat treatment process (S30) as a thermal reflow process on the pattern 20 coated with the fluoropolymer thin film 40 (S40). At this time, the heat treatment to be performed can heat the pattern to a temperature equal to or higher than the glass transition temperature (Tg).

The glass transition temperature and thermal conductivity of the pattern having thermoplastic properties may be different from the heat treatment temperature and time depending on the characteristics, the heat treatment temperature is from +100 ℃ to 300 ℃, the heat treatment time is from 1 minute to 6 hours In this embodiment, the heat treatment temperature is preferably 180 ° C. and the heat treatment time is 30 minutes.

Moreover, it is preferable that ratio of the diameter with respect to the height (thickness) of the formed fine lens 30 is 0.4 or more, and it is preferable that numerical aperture NA of the fine lens 30 is 0.25 or more.

8A is a cross-sectional view of a pattern 20 coated with a fluoropolymer thin film 40 and an image of a scanning electron microscope (Scanning Elctron Microscope, SEM) according to an embodiment of the present invention, Figure 8b is a fluoropolymer thin film coating A cross-sectional view of the fine lens 30 and an image of a scanning electron microscope (SEM) of the fine lens 30 are shown.

The thickness of each pattern 20 in FIG. 8A was measured to be 9.18 μm, and the thickness of the fine lens 30 shown in FIG. 8B was measured to be 11.08 μm.

As described above, according to the embodiment of the present invention, by applying a fluoropolymer to the substrate on which the cylindrical cylindrical photoresist pattern is formed to impart hydrophobicity, a simple manufacturing method in forming a microlens using thermal reflow can be used. It is possible to produce a good high-number lens of the area.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. I will understand. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

10: substrate 20: pattern
30: fine lens 40: fluoropolymer thin film

Claims (17)

Forming at least one cylindrical cylindrical pattern on a substrate made of glass, photo resist, polymer, silicon, or III-V semiconductor material;
Coating a fluoropolymer thin film on the top of the cylindrical pattern of the cylinder and the surface of the substrate; And
Forming a microlens by performing a heat treatment process on the pattern coated with the fluoropolymer thin film; and manufacturing a high-numbered lens using a fluoropolymer coating.
The method of claim 1,
The horizontal cross section of the cylindrical pattern has a high-numbered lens manufacturing method using a fluoropolymer coating, characterized in that it has a shape of one of a circle, a square, a hexagon.
The method of claim 1,
In the fluoropolymer thin film,
C3F8, C4F8, CHF3, Vinyl fluoride, Vinylidene fluoride, Tetrafluoroethylene, Perfluoropropylvinylether, Perfluoromethylvinylether, Chlorotrifluoro Method for producing a high-numbered lens using a fluoropolymer coating, characterized in that it is made of any one selected from the group of chloroethylene (Chlorotrifluoroethylene).
The method of claim 1,
In the step of coating the fluoropolymer thin film,
Fluoropolymer coated on the pattern and the substrate surface is a high-numbered lens manufacturing method using a fluoropolymer coating, characterized in that the coating in vacuum or air.
The method of claim 1,
In the step of performing the heat treatment process,
The pattern is a high-numbered lens manufacturing method using a fluoropolymer coating, characterized in that the heat treatment process is performed in a vacuum or air.
The method of claim 5, wherein
The heat treatment process for the pattern is a high-numbered lens manufacturing method using a fluoropolymer coating, characterized in that using the conductive or convection.
The method of claim 1,
The fine lens formed by performing the heat treatment process is a high-numbered lens manufacturing method using a fluoropolymer coating, characterized in that the spherical or aspheric form.
The method of claim 1,
The cylindrical cylindrical pattern is a high-resistance lens manufacturing method using a fluoropolymer coating, characterized in that consisting of any one of a photoresist or polymer.
The method of claim 1,
The ratio of the diameter to the height of the fine lens is at least 0.4, characterized in that the high-numbered lens manufacturing method using a fluoropolymer coating.
The method of claim 1,
The numerical aperture of the fine lens is at least 0.25, characterized in that the high-numbered lens manufacturing method using a fluoropolymer coating.
A substrate made of any one of glass, photo resist, polymer, silicon, or III-V semiconductor material;
At least one microscopic lens formed on the substrate; And
And a fluoropolymer thin film coated on the surface of the microlens and the surface of the substrate.
The method of claim 11,
The fine lens is a high-numbered lens using a fluoropolymer coating, characterized in that through the heat treatment process after forming a cylindrical pattern of the cylinder on the substrate.
The method of claim 11,
The horizontal cross section of the cylindrical pattern has a high-numbered lens using a fluoropolymer coating, characterized in that it has a shape of one of a circle, a square, a hexagon.
The method of claim 11,
The high-lens lens using a fluoropolymer coating, characterized in that the fine lens is made of any one of a photoresist or polymer.
The method of claim 11,
And said microlens has a numerical aperture of at least 0.25.
The method of claim 11,
The fine lens,
A high aperture lens using a fluoropolymer coating, characterized in that the ratio of the diameter to the height is at least 0.4.
The method of claim 11,
In the fluoropolymer thin film,
C3F8, C4F8, CHF3, Vinyl fluoride, Vinylidene fluoride, Tetrafluoroethylene, Perfluoropropylvinylether, Perfluoromethylvinylether, Chlorotrifluoro A high-aperture lens using a fluoropolymer coating, characterized in that any one selected from the group of chloroethylene (Chlorotrifluoroethylene).

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