KR100983043B1 - Master for micro lens and fabrication method of micro lens - Google Patents

Abstract

The present invention provides a microlens master, which is mounted on a light transmissive substrate and the light transmissive substrate, and includes a plurality of lens molds made of a light transmissive material. Here, the plurality of lens molds have a first surface facing upward and having a concave portion corresponding to a desired micro lens shape, and a second surface positioned opposite to the first surface and provided as a bonding surface with the light transmissive substrate. .

Description

MASTER FOR MICRO LENS AND FABRICATION METHOD OF MICRO LENS}

The present invention relates to a microlens manufacturing method, and more particularly, to a microlens master and a microlens manufacturing method capable of improving the quality of the microlens.

Recently, as portable imaging apparatuses are widely used, the demand for micro lenses having high performance is increasing. Generally, the lens replication technique using a metal mold | die etc. is known as a micro lens. This replication technique is widely used as a low cost method of manufacturing micro lenses or microlens arrays thereof.

Conventional methods for manufacturing or replicating micro lenses include a method using a modified LIGA (Lithographic-Galvanic) process, a method using isotropic etching of silicon, a method using a gray scale mask, and an electron beam (E-beam). Or a method of directly writing using a laser, a method of using a precision machining of a mold which is a master for a micro lens, and a method of using a reflow.

The conventional reflow type microlens manufacturing method may use a device called a pin-core. The pin core has a lens-shaped recess. After the photocurable resin 18 'is applied to the lens-shaped concave portion, as shown in FIG. 1, the pin core (at the lens forming position of the light transmissive substrate 11 having the partition 12 formed in the oxide or nitride pattern) is formed. 17) is moved and light is irradiated from the light transmissive substrate 11 side to form the microlens 18.

However, since the light irradiation direction is irradiated from the light transmissive substrate 11 side by the pin core 17, the outer portion is hardened first rather than the center of the lens. In this process, a large amount of shrinkage is generated at the upper end of the lens, thereby deteriorating the lens shape.

In addition, a sufficient amount of light does not reach the center, or a relatively small amount of light may be affected, which may result in incomplete curing relative to the center of the lens. When separating the pin core from the cured micro lens, the incompletely cured convex portion is deformed into a chevron shape G as shown in Fig. 2, which makes it difficult to manufacture a precise lens.

In particular, in the case of structurally repetitive work such as a wafer type lens, if the lens shape is not obtained accurately in the first step and defects occur like the above-described chevron shape, not only the lens performance is lowered, but also the yield and Mass productivity is inevitably deteriorated.

The present invention is to solve the above-mentioned problems of the prior art, one object is to ensure a more precise shape when manufacturing the lens using a reflow method to ensure a high yield and mass production master for micro lenses To provide.

Another object of the present invention is to provide a micro lens manufacturing method using a reflow method that can ensure a more precise shape to ensure high yield and mass productivity.

In order to realize the above technical problem, an aspect of the present invention,

Provided is a light transmitting substrate and a master for microlenses mounted on the light transmitting substrate and comprising a plurality of lens molds made of a light transmitting material. Here, the plurality of lens molds have a first surface facing upward and having a concave portion corresponding to a desired micro lens shape, and a second surface positioned opposite to the first surface and provided as a bonding surface with the light transmissive substrate. .

Preferably, the second surface of the plurality of lens molds has a groove portion, and further includes a transparent bonding material filled in the groove portion to bond the plurality of lens molds and the light transmissive substrate.

Preferably, the plurality of lens molds are arranged to have a predetermined distance from each other.

In certain embodiments, the light transmissive substrate can be a glass substrate.

Another aspect of the present invention provides a method for manufacturing a micro lens.

In one embodiment, there is provided a light transmissive substrate and a plurality of lens molds mounted on the light transmissive substrate, the plurality of lens molds made of a light transmissive material, the plurality of lens molds directed upward and corresponding to a desired micro lens shape. Providing a master for a microlens having a first surface having a recess and a second surface positioned opposite to the first surface and provided as a bonding surface with the light transmissive substrate, and the recesses of the plurality of lens molds Applying a photocurable transparent resin onto the microlens master so as to be filled in; and applying a transparent substrate on the microlens master applied with the photocurable transparent resin; and curing the photocurable transparent resin Irradiating light from the light transmissive substrate side to form a plurality of micro lenses, and the plurality of microlens It is formed to provide a micro lens manufacturing method comprising the step of separating the master for the microlens from the transparent substrate.

Preferably, the plurality of lens molds are arranged to have a predetermined distance from each other. In this case, the step of applying the photocurable transparent resin is performed to be filled in the space between the plurality of lens molds, the photocurable transparent resin filled in the space between the plurality of lens molds is cured to the plurality It is provided as a lens protective partition located between the micro lenses.

Preferably, the lens protection partition has a height greater than the height of the micro lens formed on the transparent substrate.

In certain embodiments, at least one of the light transmissive substrate and the transparent substrate will be a glass substrate.

In another embodiment, the method includes the steps of: providing a plurality of lens molds made of a light transmissive material, the recesses corresponding to the microlens shape and flat plate portions surrounding the recesses; Filling a photocurable transparent resin, arranging a plurality of lens molds filled with the photocurable transparent resin on the transparent substrate such that the open surface of the concave portion faces the transparent substrate, and the filled photocurable Irradiating light from the lens mold side so that the transparent resin is cured to form a plurality of micro lenses, and separating the plurality of lens molds from the transparent substrate on which the plurality of micro lenses are formed. It provides a lens manufacturing method.

Preferably, in the filling of the transparent resin and in the placing of the plurality of lens molds, the plurality of lens molds are handled by a vacuum inhaler.

In a particular example, the filling of the transparent resin may be performed by a dispensing process of dropping the transparent resin on the recess.

Preferably, the transparent substrate has a lens protective partition formed between the region where the lens mold is to be disposed. In this case, the lens protection barrier may have a height greater than the height of the micro lens formed on the transparent substrate.

According to the present invention, when the microlens is manufactured by using the reflow method, since the irradiation direction of light such as ultraviolet rays may be irradiated to the opposite direction, that is, the convex surface of the microlens may be irradiated, it may be caused by deformation or incomplete curing due to shrinkage. It is possible to prevent the defect caused by the more precise shape. As a result, the yield and mass productivity of the microlens manufacturing process using reflow can be greatly improved.

Embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

3A and 3B are schematic perspective and sectional side views showing an example of a mold for a lens that can be employed in the first embodiment of the present invention.

The lens mold 35 employed in the present embodiment is made of a light transmissive material so that light to be used in the subsequent curing process can be transmitted.

The lens mold 35 is a block body having a first surface 35a having a recess R and a second surface 35b opposite to the first surface 35a. The recess R is defined in the desired micro lens shape. Although illustrated as a rectangular parallelepiped structure in the present embodiment, the present invention is not limited thereto and may be any of various types of structures capable of securing a lens-shaped recess R. As illustrated in FIG.

The second surface 35b of the lens mold R is provided as a bonding surface with the light transmissive substrate (31 in Fig. 4A). Preferably, as shown in Figure 3b, the groove portion (H) is formed on the second surface (35b) of the lens mold (35). The groove portion H may be provided as a space for accommodating the bonding material required for bonding with the light transmissive substrate 31.

4A to 4C are cross-sectional views of processes for describing a microlens manufacturing process according to the first embodiment of the present invention.

Fig. 4A shows a microlens master employing the lens mold of Fig. 3A.

The plurality of lens molds 35 are mounted on the light transmissive substrate 31 such that the first surface on which the recess R is formed faces upward. The light transmissive substrate 31 is not limited thereto, but may be a glass substrate.

The plurality of lens molds 35 may be effectively bonded onto the light transmissive substrate 31 using a transparent bonding material (eg, UV curable acrylate) filled in the groove portion H formed on the second surface.

Preferably, as shown in Fig. 4A, the plurality of lens molds 35 are arranged to have a constant distance d from each other.

Subsequently, as shown in FIG. 4B, a liquid photocurable transparent resin 38 ′ is applied on the microlens master so as to fill the recesses R of the plurality of lens molds 35. The transparent substrate 39 is applied onto the microlens master to which the photocurable transparent resin 38 'is applied.

The transparent substrate 39 may also be a glass substrate. Next, light is irradiated from the light transmissive substrate 31 side using the light irradiation apparatus 34 so that the photocurable transparent resin 38 'is cured.

In a particular example, the photocurable transparent resin may be an ultraviolet curable resin, and the light used in the curing process may be ultraviolet light.

In this embodiment, since the lens mold 35 which is a transparent material is used, the light 38 'can be cured by irradiating light from the light transmissive substrate 31 side.

Due to this irradiation direction, light is first irradiated to the convex center portion of the lens, and a relatively high amount of light can be reached in the center region than the surrounding region. Therefore, it is possible to prevent lens shape defects such as chevrons generated when using a conventional pin core.

Then, as shown in Fig. 4C, the microlens master is separated from the transparent substrate 39 on which the plurality of microlenses 38 are formed.

Since the photocurable transparent resin 38 ′ may be filled in the space between the plurality of lens molds 35 in the resin filling process for the preceding lens, the space between the plurality of lens molds 35 is filled. The cured photocurable transparent resin may be provided as a lens protection partition S positioned between the plurality of micro lenses 38. Preferably, the lens protection partition S has a height greater than that of the microlens 38 formed on the transparent substrate 39 as shown.

On the other hand, the microlens master obtained through this separation process can be obtained as it is shown in Fig. 4A. As described above, the master according to the present embodiment can be used continuously in a repetitive lens manufacturing process, thereby ensuring a high yield of the lens having excellent optical performance and greatly improving the mass productivity.

5A and 5B are schematic perspective and sectional side views showing an example of a mold for a lens that can be employed in the second embodiment of the present invention.

As shown in Fig. 5A, the lens mold 55 employed in this embodiment has a recessed portion 55b corresponding to the micro lens shape and a flat portion 55a surrounding the recessed portion 55b. . The receiving groove R of the concave portion of the lens mold 55 is defined in the desired micro lens shape.

The lens mold 55 employed in the present embodiment is also made of a light transmissive material so that light to be used in the subsequent curing process can be transmitted. The open surface in which the recessed part 55b is formed among the said flat parts is provided as a joining surface. In addition, the opposite side may be a surface in contact with the suction port of the vacuum suction unit 57 as shown in FIG. Preferably, in the filling of the transparent resin and in the placing of the plurality of lens molds 55, the plurality of lens molds 55 are handled by the vacuum inhaler 57.

In a particular example, the filling of the transparent resin may be performed by a dispensing process using a dispenser D to drop the transparent resin onto the recess 55b.

Subsequent processes are then illustrated in FIGS. 7A-7C.

As shown in FIG. 7A, a plurality of lens molds 55 filled with the photocurable transparent resin 58 'are disposed on the transparent substrate 59. The plurality of lens molds 55 are disposed so that the open surface of the concave portion faces the transparent substrate 59.

As shown, the lens mold 55 can be handled by the vacuum inhaler 57 in this process. The lens mold 55 may be attached onto the transparent substrate 59 using known bonding means so as to have a detachable bonding state later.

Preferably, the transparent substrate 59 has a lens protective partition S formed between a region where the lens mold 55 is to be disposed. In this case, the lens protective partition S preferably has a height greater than that of the microlens to be formed on the transparent substrate 59.

Then, as shown in Fig. 7B, light is irradiated from the lens mold 55 side so that the filled photocurable transparent resin 58 'is cured. For example, the photocurable transparent resin 58 ′ may be an ultraviolet curable resin, and the light used in the curing process may be ultraviolet light.

In this embodiment, since the lens mold 55 which is a transparent material is used, the resin 58 'filled with light can be hardened by irradiating light directly from the lens mold 55 side. Therefore, light is first irradiated to the convex center portion to form the lens, and a relatively high amount of light can be reached in the center region than the surrounding region. Therefore, it is possible to prevent lens shape defects such as chevrons generated when using a conventional pin core.

As shown in FIG. 7C, the plurality of lens molds 55 are separated from the transparent substrate 59 on which the plurality of micro lenses 58 are formed. The separated lens mold 58 may be made of a material having excellent releasability, and may be implemented to be reusable by appropriately selecting an adhesive component used when attaching to the transparent substrate 59.

As such, the invention is not limited by the embodiments described above and the accompanying drawings, but is defined by the appended claims. Therefore, it will be apparent to those skilled in the art that various forms of substitution, modification, and alteration are possible without departing from the technical spirit of the present invention described in the claims, and the appended claims. Will belong to the technical spirit described in.

1 is a schematic view for explaining a conventional microlens master manufacturing process.

FIG. 2 is a schematic view showing a micro lens manufactured by the process of FIG.

3A and 3B are schematic perspective and sectional side views showing an example of a mold for a lens that can be employed in the first embodiment of the present invention.

4A to 4C are cross-sectional views of processes for describing a microlens manufacturing process according to the first embodiment of the present invention.

5A and 5B are schematic perspective and side cross-sectional views showing an example of a mold for a lens that can be employed in the second embodiment of the present invention.

FIG. 6 is a schematic view showing a resin filling process using the lens mold of FIG. 5A.

7A to 7C are cross-sectional views illustrating processes of manufacturing a microlens according to a second exemplary embodiment of the present invention.

Claims (15)

Light transmissive substrates; And A plurality of lens molds, which are disposed and mounted on the light-transmissive substrate so as to have a predetermined distance from each other to form a partition between the micro-lenses, The plurality of lens molds have a first surface facing upward and having a concave portion corresponding to a desired micro lens shape, and a second surface positioned opposite to the first surface and provided as a bonding surface with the light transmissive substrate. Master for microlenses to make. The method of claim 1, Second surfaces of the plurality of lens molds have grooves, And a transparent bonding material filled in the groove portion such that the plurality of lens molds and the light transmissive substrate are bonded to each other. delete The method of claim 1, The light transmissive substrate is a microlens master, characterized in that the glass substrate. A first transparent lens and a plurality of lens molds mounted on the light transmitting substrate, the plurality of lens molds made of a light transmissive material, the plurality of lens molds pointing upwards and having a concave portion corresponding to a desired micro lens shape; Providing a master for a microlens having a surface and a second surface positioned opposite to the first surface and provided as a bonding surface with the light transmissive substrate; Applying a photocurable transparent resin onto the microlens master so as to fill the recesses of the plurality of lens molds; Applying a transparent substrate on the microlens master to which the photocurable transparent resin is applied; Irradiating light from the light transmissive substrate side such that the photocurable transparent resin is cured to form a plurality of micro lenses; And Separating the master for the microlens from the transparent substrate on which the plurality of microlenses are formed, The plurality of lens molds are arranged to have a predetermined distance from each other, The applying of the photocurable transparent resin is performed to fill the space between the plurality of lens molds, The photocurable transparent resin filled in the space between the plurality of lens molds is cured and provided as a lens protection partition located between the plurality of micro lenses. The method of claim 5, Second surfaces of the plurality of lens molds have grooves, And a transparent bonding material filled in the groove so that the plurality of lens molds and the light transmissive substrate are bonded to each other. delete The method of claim 5, The lens protective partition wall has a height greater than the height of the micro lens formed on the transparent substrate. The method of claim 5, At least one of the light transmissive substrate and the transparent substrate is a glass substrate. Providing a plurality of lens molds made of a light transmissive material and having a recess corresponding to a micro lens shape and a flat plate surrounding the recess; Filling a photocurable transparent resin into a recess of each lens mold; Disposing a plurality of lens molds filled with the photocurable transparent resin on the transparent substrate such that the open surface of the concave portion faces the transparent substrate; Irradiating light on the lens mold side so that the filled photocurable transparent resin is cured to form a plurality of micro lenses; And Separating the plurality of molds for the lens from the transparent substrate on which the plurality of micro lenses are formed, And the transparent substrate has a lens protective partition formed between a region where the lens mold is to be disposed. The method of claim 10, Filling the transparent resin and disposing the plurality of lens molds, wherein the plurality of lens molds are handled by a vacuum inhaler. The method of claim 10, The filling of the transparent resin is performed by a dispensing process of dripping the transparent resin into the concave portion. delete The method of claim 10, The lens protective partition wall has a height greater than the height of the micro lens formed on the transparent substrate. The method of claim 10, The transparent substrate is a glass lens manufacturing method, characterized in that the glass substrate.

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