JP2004351838A - Method for producing duplication mold for micro-lens array - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a duplication mold for a micro-lens array which can accurately and stably form a recession corresponding to a minute lens shape and can easily produce a large-sized mold. <P>SOLUTION: The method includes a resin layer forming process in which an uncured ultraviolet curable resin layer 2 is formed on a substrate 1, a curing process in which beads 3 are immersed in the uncured layer 2 to a prescribed depth to cure the uncured layer 2, and a separation process in which the beads 3 are separated from the cured layer 2 by dissolution or by applying etching and ultrasonic vibration. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a replication mold for a microlens array.
[0002]
[Prior art]
As a method of manufacturing a mold for duplicating a microlens array, there is a manufacturing method described in Patent Document 1 in which a substrate made of metal or the like is manufactured by cutting the substrate with a diamond member.
In addition, in order to reduce the time and cost required for metal processing, resin is dropped on a master having a lens-shaped pattern formed by photolithography to form a layer, and the resin is cured while the substrate is placed on this, and the pattern is formed. There is a production method described in Patent Literature 2 in which a duplicate mold is obtained by a method of transferring a resin to a resin.
[0003]
[Patent Document 1]
JP 2002-144348 A [Patent Document 2]
JP 2002-321227 A
[Problems to be solved by the invention]
However, in the conventional cutting method, a long time is required for processing, so that the mold is expensive, and it is practically difficult to manufacture a large mold in particular.
Further, a portion corresponding to the lens portion requires fine cutting, and therefore, a tool requires high precision and is expensive. Further, the service life of the tool is shortened, so that the tool must be frequently replaced with a new tool. Further, there is a problem that the machining accuracy cannot be stably maintained due to wear of the tool.
Also, in the manufacturing method of forming a pattern by photolithography, manufacturing a large-sized replication mold requires large-scale photolithography equipment, which is difficult to manufacture.
[0005]
The problem to be solved by the present invention is to provide a method for manufacturing a replica mold for a microlens array that can stably form a concave portion corresponding to a fine lens shape with high precision, and that can be easily manufactured at low cost. To provide.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has the following configuration as means.
That is, the invention according to claim 1 is a method for manufacturing a microlens array duplication mold used in a microlens array manufacturing method, wherein a resin layer forming step of providing an uncured ultraviolet-curable resin layer 2 on the base material 1 is performed. A curing step of immersing a plurality of beads 3 in the uncured UV-curable resin layer 2 to a predetermined depth to cure the uncured UV-curable resin layer 2; And a desorption step of desorbing the beads 3 by dissolution or etching.
The invention according to claim 2 is characterized in that, in the detaching step, the beads 3 are detached from the cured ultraviolet-curable resin layer 2 by the dissolution or the etching and the application of ultrasonic vibration. 2. The method of manufacturing a replica mold for a microlens array according to claim 1, wherein
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a diagram showing an example of a replication mold manufactured by an embodiment of the method of manufacturing a replication mold for a microlens array according to the present invention;
FIG. 2 is a diagram for explaining a method of manufacturing a replication mold for a microlens array according to the present invention;
FIG. 3 is a view for explaining a method for producing a microlens array using the replica mold manufactured in the embodiment of the method for manufacturing a replica lens for a microlens array of the present invention.
[0008]
The method of manufacturing a replication mold for a microlens array according to the present invention includes immersing a part of microbeads having a predetermined size in an ultraviolet curable resin, curing the ultraviolet curable resin in that state, and removing the immersed microbeads. It is a manufacturing method.
FIG. 1 shows an example of a replication mold 10 for a microlens array manufactured by this method.
FIG. 1A is a perspective view thereof, in which concave portions 10A corresponding to lens portions are formed in a two-dimensional array of six rows and six columns.
FIG. 1B is a sectional view showing an AA section of FIG. 1A.
Hereinafter, this manufacturing method will be described in detail in the order of steps with reference to FIGS. 2 (a) to 2 (d).
[0009]
(Step 1) [see FIG. 2 (a)]
An ultraviolet curable resin 2 is applied on the duplication-type substrate 1. Of course, the method is not limited to coating, and the uncured ultraviolet curable resin 2 may be formed in a layered manner.
[0010]
(Step 2) [See FIGS. 2 (b) and 2 (c)]
A bead fixing base material 4 in which a plurality of beads 3 having a predetermined diameter R are two-dimensionally arranged and fixed at a predetermined pitch P is prepared in advance, and this bead fixing base material 4 is lowered from above in the direction of the arrow and provided in step 1. The beads 3 are immersed in the uncured layer of the ultraviolet curable resin 2 to a predetermined depth D.
The diameter R of the beads, the arrangement pitch P, and the immersion depth D are set according to the predetermined lens part shape of the microlens array to be manufactured.
For example, if the microlens has a hemispherical shape, D = R / 2.
[0011]
(Step 3) [See FIG. 2 (c)]
The ultraviolet curing resin 2 is irradiated with ultraviolet UV to cure it.
When the beads 3 are formed of a material that is impermeable to ultraviolet light, the material of the replication-type base material 1 is formed of an ultraviolet transmission material, and ultraviolet light UV is irradiated from the base material 1 side (the lower part in the figure). Of course, when the beads 3 and the bead fixing base material 4 and the beads 3 are fixed with an adhesive, the beads 3 are formed of an ultraviolet transmitting material including the adhesive, and even if the ultraviolet rays are irradiated from above in the figure, Good.
[0012]
(Step 4) [see FIG. 2 (d)]
Next, the beads 3 are removed by dissolving or etching.
At the time of this removal, the beads 3 may be completely dissolved, but if the interface between the beads 3 and the ultraviolet curable resin 2 is dissolved, or if about half of the part where the beads 3 are immersed can be removed, By applying ultrasonic vibration to the base material 1 and the beads 3, the beads 3 can be detached from the ultraviolet curable resin 2. Upon completion of the detachment, the replica mold 10 for the microlens array shown in FIG. 1 is obtained.
In this case, the ultrasonic vibration may be applied at a frequency of 26 kHz, an output of 300 W, and an application time of 5 minutes, for example. This condition is not limited and can be set as appropriate.
FIG. 2D shows a state where the immersion portion of the beads 3 is almost dissolved to form the gap F.
[0013]
By the above-mentioned (Step 1) to (Step 4), the replica mold 10 for the microlens array can be manufactured.
[0014]
Next, a first embodiment to a third embodiment will be sequentially described as embodiments in which the microlens array duplication mold 10 is manufactured by the above-described steps.
[0015]
<First embodiment>
The spherical microbeads 3 made of nickel and having a diameter R = 100 μm are fixed to a bead fixing base material 4 made of an acrylic material with an arrangement pitch P = 120 μm with an acrylic transparent adhesive (not explicitly shown in the drawing), and are transparent. It was immersed in an ultraviolet curing resin 2 applied on a substrate 1 made of a polycarbonate material at an immersion depth D = 50 μm.
After the ultraviolet curable resin 2 was cured by irradiating ultraviolet rays from the substrate 1 side, the beads 3 were etched with aqua regia to remove the interface with the ultraviolet curable resin 2.
Thereafter, ultrasonic vibration was applied to the substrate 1 and the beads 3 in water, and the remaining beads 3 were completely removed from the ultraviolet-curing resin 2 to obtain the microlens array duplication mold 10.
As the UV-curable resin 2, a urethane-based UV-curable resin (EX-8210, manufactured by Dainippon Ink and Chemicals, Inc.) was used.
[0016]
<Second embodiment>
The spherical microbeads 3 made of glass having a diameter R = 80 μm are fixed to a transparent bead fixing substrate 4 made of a polycarbonate material at an arrangement pitch P = 90 μm with an acrylic transparent adhesive (not explicitly shown in the figure). It was immersed in an ultraviolet curing resin 2 applied on a substrate 1 made of an acrylic material at an immersion depth D = 40 μm.
After the ultraviolet curable resin 2 was cured by irradiating ultraviolet rays from the bead fixing base material 4 side, the beads 3 were etched with a mixed solution of hydrofluoric acid and ammonium fluoride, and the interface with the ultraviolet curable resin 2 was removed. .
Thereafter, ultrasonic vibration was applied to the base 1 and the beads 3 in water, and the remaining beads 3 were completely removed from the ultraviolet-curable resin 2 to obtain the microlens array duplication mold 10.
As the ultraviolet curing resin 2, an acrylic ultraviolet curing resin (T3087B, manufactured by Three Bond Co., Ltd.) was used.
[0017]
<Third embodiment>
The spherical microbeads 3 made of wax having a diameter R = 120 μm are fixed to a bead fixing base material 4 made of an acrylic material at an arrangement pitch P = 140 μm with an acrylic transparent adhesive (not shown in the figure), and the transparent microbeads 3 are transparent. It was immersed in an ultraviolet curing resin 2 applied on a substrate 1 made of a polycarbonate material at an immersion depth D = 60 μm.
After the ultraviolet curable resin 2 was cured by irradiating ultraviolet rays from the side of the substrate 1, the beads were dissolved by heating and completely removed from the ultraviolet curable resin 2 to obtain a microlens array duplication mold 10.
As the ultraviolet curing resin 2, an acrylic ultraviolet curing resin (T3087B, manufactured by Three Bond Co., Ltd.) was used.
[0018]
Next, a microlens array was prepared from the microlens array duplication mold 10 manufactured according to the first to third embodiments.
First, as shown in FIG. 3A, an ultraviolet curable resin 6 was applied on the surface of the duplicate mold, and a transparent array substrate 7 was disposed thereon.
After curing the ultraviolet-curable resin 6 by irradiating ultraviolet rays, the microlens array 8 was obtained by peeling the cured resin 6 from the replica mold as shown in FIG. 3B.
It was confirmed that the microlens array 8 had a spherical lens portion 8A formed with high precision and had sufficient required performance.
[0019]
The embodiment of the present invention is not limited to the above-described configuration, and may be modified without departing from the gist of the present invention.
[0020]
For example, the thickness of the ultraviolet curing resin provided in a layer, the diameter of the beads 3, the pitch P, the immersion depth, and the like can be appropriately set according to the shape of the microlens array produced by the duplication mold manufactured in this embodiment. is there.
[0021]
The means for fixing the beads 3 to the bead fixing substrate 4 is not limited.
Further, the beads 3 may be supported by a supporting means other than the bead fixing substrate 4 and immersed in the ultraviolet curable resin 2 applied on the substrate 1 at a predetermined immersion depth.
[0022]
The bead fixing substrate 4 and other supporting means are not limited to those integrally formed.
For example, beads may be fixed to a partial base material obtained by dividing a base material having a predetermined size, and a plurality of the beads may be combined to form a bead fixing base material having a predetermined size.
Further, instead of supporting the beads 3 by the supporting means, the beads 3 may be scattered on the ultraviolet curable resin 2 applied on the substrate 1 and immersed at a predetermined depth.
[0023]
In the above embodiment, when the beads 3 are etched and desorbed, the ultrasonic vibration is applied to the base 1 and the beads 3 in water after the etching process. May be. In this case, the efficiency of desorption of the beads 3 is improved, and it is not necessary to move the substrate 1 or the like into water, so that the number of steps can be reduced.
In dissolving the beads 3, ultrasonic vibration may be applied simultaneously with the dissolution treatment. Thereby, desorption can be promoted and desorption efficiency can be improved.
[0024]
【The invention's effect】
As described in detail above, according to the method of manufacturing a replica mold for a microlens array of the present invention, a concave portion corresponding to a lens shape can be formed stably with high accuracy, and a low-cost, large-sized mold can be easily manufactured. The effect is obtained.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a replica manufactured by an embodiment of a method of manufacturing a replica for a microlens array according to the present invention.
FIG. 2 is a diagram for explaining a method of manufacturing a replication mold for a microlens array of the present invention, and is a cross-sectional view showing an embodiment of an electroacoustic transducer of the present invention.
FIG. 3 is a view for explaining a method of producing a microlens array using the replica mold manufactured in the embodiment of the method for manufacturing a replica mold for a microlens array of the present invention.
[Explanation of symbols]
1 Base material 2, 6 UV curable resin (layer)
Reference Signs List 3 beads 4 bead fixing base material 7 array base material 8 micro lens array 8A lens portion 10 duplication mold 10A concave portion R (bead) diameter P (arrangement) pitch D (immersion) depth

Claims (2)

In a method for manufacturing a replication type for a microlens array used in a method for manufacturing a microlens array,
A resin layer forming step of providing an uncured ultraviolet curable resin layer on the base material,
A curing step of immersing a plurality of beads in the uncured UV-curable resin layer to a predetermined depth to cure the uncured UV-curable resin layer,
A step of dissolving or etching the beads from the cured ultraviolet curable resin layer by dissolving or etching. 2. The microlens array copy according to claim 1, wherein the detachment step detaches the beads from the cured ultraviolet-curable resin layer by the dissolution or the etching and the application of ultrasonic vibration. 3. Mold manufacturing method.

Images