KR101202896B1 - Making Method for Micro Lens Array - Google Patents

Abstract

A microlens array manufacturing method comprising a microlens array and a focused mask pattern formed by the microlens array, comprising: coating a black photoresist on one surface of the microlens array; A curing step of irradiating ultraviolet rays to the micro lens array to cure the black photoresist on a focal point of the micro lens array; And developing to remove the cured portion of the black photoresist. It provides a micro lens array manufacturing method consisting of.
The present invention has the effect of forming a mask pattern on the focal region formed by the lens on the micro lens array to facilitate alignment of the micro lens and the mask pattern.

Description

Making Method for Micro Lens Array

The present invention relates to a method for manufacturing a microlens array, and more particularly, to a method for manufacturing a microlens array, which facilitates alignment of a pattern in which a microlens is in focus.

Microlenses are defined as lenses having a diameter of less than 1 millimeter, but lenses with a diameter of 5 millimeters or more are sometimes considered as microlenses.

In general, a display device, an optical communication component, or a light emitting diode device is equipped with a lens, in particular, a micro lens to control light convergence, diffusion, and reflection (hereinafter, 'lens' includes a 'micro lens'). It is important to control the focal point formed by the lens such that the lens can have the desired optical properties.

The microlens array, in which a plurality of microlenses are arranged, has a problem that it is very difficult to align a mask pattern in which focus is formed by the microlens and the microlens due to the small size of the lens.

The present invention has been made to solve the above problems, and provides a method of manufacturing a micro lens array to form a mask pattern on the focusing portion formed by the lens on the micro lens array to facilitate alignment of the micro lens and the mask pattern. It aims to do it.

A microlens array manufacturing method comprising a microlens array and a focused mask pattern formed by the microlens array, the method comprising: coating a black photoresist on one surface of the microlens array; A curing step of irradiating ultraviolet rays to the micro lens array to cure the black photoresist on a focal point of the micro lens array; And developing to remove the cured portion of the black photoresist. It provides a micro lens array manufacturing method consisting of.

The microlens array includes a master plate preparing step of preparing a master plate having a plurality of forming grooves formed on one side thereof in a vacuum chamber; A light shielding film preparation step of forming a light shielding film to block light transmission by applying metal deposition or ink or a black matrix between the molding grooves; A substrate preparation step of preparing a substrate to be a raw material of a micro lens in the vacuum chamber; Forming a vacuum in the vacuum chamber; An adhesion step of bringing the master plate into close contact with the substrate; A heating step of heating the substrate; A vacuum release step of releasing the vacuum in the vacuum chamber; And a lens forming step of forming a lens by separating the master plate and the substrate. It can be prepared by.

The method may further include a substrate cooling step of cooling the substrate and the master plate to a temperature at which deformation does not occur.

The melting point of the metal or the evaporation temperature of the ink and the black matrix forming the light blocking film may be higher than the temperature applied to the substrate in the heating step.

The duration of the lens forming step may be increased or decreased depending on the degree of curvature of the micro lens.

The coating surface of the black photoresist may be a focal plane of the ultraviolet light emitted to the micro lens array.

The ultraviolet light may be parallel to the optical axis of the micro lens.

As described above, the present invention has an effect of forming a mask pattern on a focal region formed by a lens on a micro lens array to easily align the micro lens and the mask pattern.

1 is a view showing an example of a microlens array manufacturing apparatus for implementing a microlens array manufacturing method according to the present invention.
FIG. 2 is a diagram illustrating an example of an operation of the apparatus illustrated in FIG. 1.
3 is a flowchart illustrating a method of manufacturing a microlens array according to the present invention.
4 is a flowchart illustrating a method of manufacturing a micro lens array, which is further included in FIG. 3.
FIG. 5 is a diagram illustrating a microlens array for each stage according to the manufacturing method illustrated in FIG. 4.
FIG. 6 is a diagram illustrating a microlens array for each stage according to the manufacturing method illustrated in FIG. 3.

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

1 is a view showing an example of a microlens array manufacturing apparatus for implementing a method of manufacturing a microlens array according to the present invention, Figure 2 is a view showing an example of the operation of the apparatus shown in FIG.

1 and 2, the lens manufacturing apparatus 100 for implementing a method of manufacturing a micro lens array includes a vacuum chamber 110, a vacuum unit 120, a lifting cylinder 130, and a lower frame 140a. , The upper frame 140b and the controller 150.

The vacuum chamber 110 forms a vacuum therein to provide a lens manufacturing space. The vacuum chamber 110 is selectively sealed as the work progresses, and may maintain or release the vacuum.

In addition, one side of the vacuum chamber 110 may be provided with a vacuum unit 120 for selectively forming the interior of the vacuum chamber 110 in a vacuum state.

The vacuum unit 120 may be provided with a vacuum pump (not shown) for forming a vacuum pressure and a fluid line (not shown) for moving a fluid such as air, but a detailed description thereof will be omitted.

The lifting cylinder 130 allows lifting and lowering of the upper frame 140b to be described later. The lifting cylinder 130 may be a pneumatic cylinder or a hydraulic cylinder, but other lifting elements may be used as long as the lifting and lowering of the upper frame 140b is easily performed.

One or more guide rods 131 may be connected to the upper frame 140b to guide the lifting and lowering of the upper frame 140b by the lifting cylinder 130.

The lower frame 140a is installed on the bottom surface of the vacuum chamber 110, and a master plate 160 for manufacturing the micro lens array is disposed on the upper surface thereof. In addition, the heating unit 141 for applying heat to the master plate 160 is disposed on the lower frame 140a side. The heating unit 141 includes a hot wire heater, and when the heating unit 141 first heats the master plate 160, heat applied to the master plate 160 is transferred to the substrate 170 above the master plate 160. Is transferred to heat the substrate 170.

The upper frame 140b is installed at a predetermined height above the lower frame 140a. The lower surface of the upper frame 140b is mounted with a lens array substrate 170 which is a raw material of the lens. The upper frame 140b is in close contact with the substrate 170 after it is seated on the master plate 160. In addition, after the microlens is formed on the substrate 170, the substrate 170 on the master plate 160 is separated.

The mounting of the substrate 170 by the upper frame 140b is as shown in FIG. 2.

The control unit 150 is installed outside the vacuum chamber 110. The controller 150 controls the operations of the vacuum unit 120 and the lifting cylinder 130 according to the shape of the lens input by the user.

Meanwhile, when the substrate 170 is separated on the master plate 160 after the microlens is formed, a cooler supply unit supplying cooling air for cooling the substrate 170 to an appropriate temperature to prevent deformation of the substrate 170. (Not shown) may be further included.

3 is a flowchart illustrating a method of manufacturing a microlens array according to the present invention.

Referring to FIG. 3, the method of manufacturing a micro lens array includes a black photoresist coating step S200, an ultraviolet irradiation step S210, and a black photoresist developing step S220.

Here, the following process may be further preceded in order to perform the manufacturing method of the micro lens array. Let's look at this.

4 is a flowchart illustrating a method of manufacturing a micro lens array, which is further included in FIG. 3.

Referring to FIG. 4, a method of manufacturing a micro lens array includes a master plate preparing step (S110), a light shielding film preparing step (S120), a substrate preparing step (S130), a vacuum forming step (S140), an adhesion step (S150), and a heating step. (S160), a vacuum release step (S170), a lens forming step (S180), and a substrate cooling step (S190).

5 is a view showing each stage of the micro lens array according to the manufacturing method shown in FIG.

A fabrication of a micro lens array will be described with reference to FIGS. 4 and 5.

First, the master plate preparing step (S110) is a step of disposing the master plate 160, which is the basis for manufacturing the required micro lens array, inside the vacuum chamber 110, and the master plate 160 includes the vacuum chamber 110. It is seated on the upper portion of the lower frame 140a disposed inside.

Referring to FIG. 5A, the master plate 160 is formed in a flat plate shape having a predetermined area, and a plurality of forming grooves 161 are formed on the upper surface of the master plate 160 at regular intervals. Molding groove 161 is a hemispherical groove, the depth of the molding groove 161 is formed larger than the thickness of the lens to be actually manufactured. Here, the forming groove 161 is limited to a hemispherical groove, but it will be said that the grooves of other shapes (eg, cylindrical) can also be used according to the use of the lens manufactured as an example. In addition, the number of the forming grooves 161 is determined according to the user's needs such as the number of micro lenses to be produced once.

In the light shielding film preparation step (S120), a predetermined metal is deposited between a plurality of molding grooves 161 formed in the master plate 160, or a predetermined ink or black matrix is coated to form the light shielding film 180.

Referring to FIG. 5B, when the microlens array is completed, a metal material, ink, or black matrix on the master plate 160 is attached to the microlens array to block light between the microlenses. Acts as. Here, the metal material and ink serving as the light shielding film may block light, and any material may be used as long as the material is not damaged by heat applied during the process.

The black matrix is a black coating layer formed by coating a black photoresist. The black matrix is black in color, so it can block light emitted between the micro lenses.

The melting point temperature of the metal forming the light blocking film 180 and the evaporation temperature of the ink and the black matrix are higher than the temperature applied to the substrate 170 in the heating step S160 described later, and the metal during the heating step S160 is performed. However, the ink or black matrix must not melt or evaporate by heat.

In the substrate preparation step (S130), the substrate 170, which is a raw material of the microlenses, is disposed in the vacuum chamber 110. As the substrate 170, a polymer film made of a polymer material may be used. Here, the material of the substrate 160 is selected according to the type of the lens, and generally, materials such as polycarbonate (PC), polymethyl methacrylate (PMMA), and polystyrene (PS) may be used. have.

The prepared substrate 170 is disposed on the lower side of the upper frame 140b.

In the vacuum forming step S140, the inside of the vacuum chamber 110 is set to a vacuum by using the vacuum unit 120. In this case, the vacuum pressure of the vacuum chamber 110 is adjusted according to the shape of the micro lens to be molded. That is, when the user selects the reference lens, the controller 150 controls the vacuum unit 120 to form the vacuum degree of the vacuum chamber 110 at a preset reference value.

The substrate adhesion step (S150) allows the substrate 170 on the master plate 160 to be in close contact with the master plate 160 so that the internal space of the molding groove 161 is isolated from the outside. That is, the upper frame 140b is lowered by the operation of the lifting cylinder 130, and the substrate 170 contacts the upper surface of the master plate 160. Then, the close contact between the master plate 160 and the substrate 170 is the upper frame 140b is moved to the lower side, the substrate 170 is in contact with the upper surface of the master plate 160, the upper frame 140b is The upper surface of the substrate 170 is pressed by a predetermined pressure.

Referring to FIG. 5C, the inner space of the forming groove 161 is isolated from the outside by the close contact between the master plate 160 and the substrate 170.

In the heating step S160, a predetermined heat is applied to the substrate 170 while the master plate 160 is in close contact with the substrate 170. That is, the heating unit 141 operates the hot wire heater to heat the master plate 160. Heat applied to the master plate 160 is transferred to the substrate 170 above the master plate 160 to heat the substrate 170.

The substrate 170 heated through the master plate 160 is preferably heated to 100 to 300 ° C. When the substrate 170 is heated below 100 ° C., the deformation of the substrate does not occur in the lens forming step S180 to be described later, so that lens formation is not performed smoothly, and the substrate 170 is heated to 300 ° C. or more. In this case, too much deformation of the substrate 170 may occur, such that the lens may not be formed with an accurate curvature.

The vacuum releasing step (S170) is a step of releasing the vacuum in the vacuum chamber 110 while the master plate 160 and the substrate 170 are in close contact with each other. That is, the vacuum unit 120 is controlled to open the vacuum chamber 110 so that the vacuum in the vacuum chamber 110 is released.

In the lens forming step S180, a plurality of lenses, which are micro-convex lenses, are formed on one surface of the substrate 170 by a pressure difference between the vacuum chamber 110 in which the vacuum is released and the forming groove 161.

This will be described in more detail.

When the vacuum inside the vacuum chamber 110 is released by the opening of the vacuum chamber 110, the inside of the vacuum chamber 110 is maintained at atmospheric pressure, whereas the inside of the forming groove 161 is kept in vacuum to generate a pressure difference. By the pressure difference, the substrate 170 is convexly formed in the inward direction of the forming groove 161 to form a lens. Accordingly, a micro lens is formed on one surface of the substrate 170. In this case, the shape of the lens varies depending on the time (lens formation time) from when the vacuum of the vacuum chamber 110 is released to when the substrate 170 and the master plate 160 are separated. Accordingly, the duration of the lens forming step (S180) is adjusted.

Referring to FIG. 5D, a convex lens-type micro lens having a predetermined curvature is formed on a front surface of the substrate 170 separated from the master plate 160, and a rear surface is formed in a planar shape. Here, since the size of the pattern to be described later corresponds to the focal length of the microlens, the curvature of the microlens is adjusted according to the size of the pattern required by the user to obtain the required focal length.

Although the substrate cooling step S190 may be performed after the formation of the microlens is completed, the substrate cooling step S190 may be performed at the same time as the lens forming step S180 to quickly perform the formation of the microlens.

After the microlens having the curvature required by the user is formed on the substrate 170, the substrate 170 is separated on the master plate 160. When the substrate 170 is separated from the master plate 160, the substrate 170 is cooled by supplying a cooling gas having a predetermined temperature into the vacuum chamber 110 to prevent deformation of the substrate 170. Cooling is to be made (S190). In this case, the supplied gas may be at room temperature and may be air of a specific temperature.

When the temperature of the substrate 170 is cooled to such an extent that deformation does not occur, the separation of the substrate 170 is performed by lifting and lowering the upper frame 140b by the operation of the lifting cylinder 130 so that the substrate 170 is the master plate 160. ).

Referring to FIG. 5E, after the master plate 160 and the substrate 170 are cooled to a predetermined temperature, the light shielding film 180 is formed on the substrate 170 separated from the master plate 160. It can be seen that the convex lens-type micro lens array is formed of a plurality of micro lenses.

FIG. 6 is a diagram illustrating a microlens array for each stage according to the manufacturing method illustrated in FIG. 3.

Referring to Figures 3 and 6 will be described in the manufacture of the micro lens array.

Referring to FIG. 6A, the black photoresist layer 210 is coated on one surface of the micro lens array 200 (S200). At this time, the surface on which the black photoresist layer 210 is coated is a planar portion of the microlens array 200 by the convex lens-shaped microlens in which the ultraviolet rays irradiated in the ultraviolet irradiation step described later are formed on the microlens array 200. It is preferable that it is a focal plane focused.

After the black photoresist layer 210 is coated, the micro lens array 200 is irradiated with ultraviolet (UV) (S210). At this time, as shown in (b) of FIG. 6, the irradiation direction of ultraviolet rays is irradiated toward the micro lens array 200 from the opposite side of the black photoresist layer 210. In addition, it is preferable that the ultraviolet rays to be irradiated are parallel to the optical axis of each unit micro lens 202. In this case, the light blocking film 180 formed on the micro lens array 200 prevents the ultraviolet light incident in the non-axis direction of the unit micro lens 202 from being irradiated to the black photoresist layer 210.

The irradiated ultraviolet rays form a focus on the black photoresist layer 210 by each unit microlens 202, and are irradiated intensively to the focus site. Therefore, of the black photoresist on the black photoresist layer 210, the black photoresist on the focal plane of the unit micro lens 202 is cured by ultraviolet irradiation. Since the focal point of the unit microlens 202 is formed to have a predetermined size, the black photoresist curing unit 212 having a predetermined size is formed on the black photoresist layer 210.

Thereafter, the photoresist curing unit 212 is removed from the transparent film 210 by performing a process such as development (S220), so as to be shown in FIG. 6C.

The portion where the black photoresist cured portion 212 is located is formed with a pattern in the form of a hole through which light rays can pass. Here, the user can obtain the required size of the pattern by changing the focal length of the unit micro lens 202 on the micro lens array 200.

In the present invention configured as described above, the microlenses and microlenses are formed by forming a focal point by a microlens on the microlens array to cure the black photoresist of the focal spot and remove only the cured black photoresist to form a focus. The alignment of the mask pattern which is in focus can be easily made.

While the present invention has been described with reference to exemplary embodiments, 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. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

1: lens making device
10: vacuum chamber
20: vacuum part
30: lifting cylinder
40: lower frame
50: upper frame
60: master edition
70: substrate
80: control unit
200: micro lens array
210: black photoresist layer

Claims (7)

A microlens array manufacturing method comprising a microlens array and a focused mask pattern formed by the microlens array,
Coating a black photoresist on one surface of the micro lens array;
A curing step of irradiating ultraviolet rays to the micro lens array to cure the black photoresist on a focal point of the micro lens array; And
A developing step of developing and removing a cured part of the black photoresist; Including,
The micro lens array is
A master plate preparing step of preparing a master plate having a plurality of forming grooves formed in one side in a vacuum chamber;
A light shielding film preparation step of forming a light shielding film for depositing a metal between the forming grooves or applying ink or a black matrix to block light transmission;
A substrate preparation step of preparing a substrate to be a raw material of a micro lens in the vacuum chamber;
Forming a vacuum in the vacuum chamber;
An adhesion step of bringing the master plate into close contact with the substrate;
A heating step of heating the substrate;
A vacuum release step of releasing the vacuum in the vacuum chamber; And
A lens forming step of forming a lens by separating the master plate and the substrate;
The manufacturing method of the micro lens array manufactured by the. delete The method of claim 1,
And a substrate cooling step of cooling the substrate and the master plate to a temperature at which deformation does not occur. The method of claim 1,
Melting point of the metal or the evaporation temperature of the ink and the black matrix forming the light shielding film is higher than the temperature applied to the substrate in the heating step. The method of claim 1,
The duration of the lens forming step is increased or decreased according to the degree of curvature of the micro lens. The method of claim 1,
And a coating surface of the black photoresist is a focal plane of the ultraviolet rays irradiated onto the micro lens array. The method of claim 1,
And said ultraviolet rays are parallel to the optical axis of said microlenses.

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