JP3610297B2 - MICROSTRUCTURE ARRAY AND METHOD FOR MANUFACTURING THE SAME - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mold for producing a micro structure array such as a micro lens array used in the field of optoelectronics or the like (in this specification, a mold is referred to as a mold unless otherwise specified). And a manufacturing method such as a mold master).
[0002]
[Prior art]
A microlens array is composed of a plurality of small, substantially hemispherical lenses having a diameter of several μm to several hundreds of μm, and is used for various applications such as liquid crystal display devices, light receiving devices, and fiber-to-fiber connections in an optical communication system. It has become like this.
[0003]
On the other hand, the development of surface emitting lasers and the like that can narrow the interval between the light emitting elements and can be easily arrayed has progressed, and the demand for microlenses that can narrow the interval between lens arrays and have a large numerical aperture (NA) is increasing.
[0004]
Similarly, in the light receiving element, with the development of the semiconductor process technology, the element interval is narrowed, and the light receiving element is increasingly miniaturized as seen in a CCD or the like. As a result, here again, a microlens array having a small lens interval and a large numerical aperture is required. In such a microlens, there is a demand for a microlens having a high condensing rate with high utilization efficiency of light incident on the lens surface.
[0005]
Further, there are similar demands in the field of optical information processing, which is expected in the future, such as optical parallel processing / calculation and optical interconnection.
[0006]
In addition, research and development of self-luminous display devices such as electroluminescence (EL) have been extensively conducted, and high-definition and high-luminance displays have been proposed. In such a display, there is a demand for a low-cost and large-area microlens array in addition to a microlens array having a small size and a large numerical aperture.
[0007]
[Problems to be solved by the invention]
Under the circumstances as described above, conventionally, an ion exchange method (M. Oikawa, et al., Jpn. J. Appl. Phys. 20 (1) L51-54, 1981) is used on a substrate made of multicomponent glass. A method of manufacturing a microlens array in which a plurality of lenses are formed by increasing the refractive index at a plurality of locations is known. However, with this method, it is difficult to design a lens having a large numerical aperture because the aperture diameter of the lens cannot be made larger than the distance between the lenses.
[0008]
Moreover, in order to produce a large-area microlens array, a large-scale manufacturing apparatus such as an ion diffusion apparatus is required, and there is a problem that manufacturing is not easy. In addition, it is necessary to perform an ion exchange process for each glass compared to molding using a mold. If manufacturing conditions of manufacturing equipment are not sufficiently managed, variations in lens quality, such as focal length, will be large between lots. There was a problem of becoming. Moreover, this method becomes expensive compared with the method using a metal mold | die.
[0009]
Furthermore, in the ion exchange method, alkali ions for ion exchange are essential in the glass substrate, and the compatibility of the substrate material is limited to alkali glass and the semiconductor-based device is premised on alkali ion free. Furthermore, since the thermal expansion coefficient of the glass substrate itself is significantly different from the thermal expansion coefficient of the substrate of the light receiving device or the light emitting device, misalignment due to mismatch of the thermal expansion coefficients occurs as the integration density of the elements increases. Originally, the ion exchange method on the glass surface is known to leave a compressive strain on the surface, which inevitably causes a trade-off problem between residual stress on the glass surface and warpage deformation, and the microlens array becomes large. Accordingly, it becomes difficult to bond and join the light receiving device and the substrate of the light emitting device.
[0010]
As another method, there is a method in which an original plate of a microlens array is manufactured, a lens material is applied to the original plate, and the applied lens material is peeled off. In producing a mold as an original plate, there are a method of drawing using an electron beam (Japanese Patent Laid-Open No. 1-261601) and a method of forming a part of a metal plate by etching (Japanese Patent Laid-Open No. 5-303099). . In these methods, microlenses can be duplicated by molding, and variations among lots are unlikely to occur, and can be manufactured at low cost. In addition, problems such as alignment errors and warping due to a difference in thermal expansion coefficient can be avoided as compared with the ion exchange method. However, in the method using an electron beam, an electron beam drawing apparatus is expensive and requires a large amount of capital investment, and the drawing area is limited. There are problems such as difficulty.
[0011]
In addition, the etching method uses isotropic etching mainly utilizing a chemical reaction, so that there is a problem that if the composition or crystal structure of the metal plate changes even slightly, it cannot be etched into a desired shape. In the etching method, if the desired shape is obtained, the etching is continued unless it is immediately washed with water. In the case of forming a microlens, there is a case where the desired shape is deviated due to etching that proceeds from the time when the desired shape is obtained to the time of washing with water.
[0012]
As another method, there is a registry flow method (D. Daly, et al., Proc. Microlens Arrays Teddington, p23-34, 1991). In this method, a resin formed on a substrate is patterned into a cylindrical shape using a photolithography process, heated and reflowed to produce a microlens array. By this method, lenses having various shapes can be manufactured at low cost. In addition, there are no problems such as thermal expansion coefficient and warpage as compared with the ion exchange method.
[0013]
[Problems to be solved by the invention]
However, in this registry flow method, when adjacent lenses are brought into contact with each other by reflow, a desired lens shape cannot be maintained due to surface tension. That is, it is difficult to increase the light collection rate by touching adjacent lenses to reduce the light unused area between the lenses.
[0014]
The present invention has been made in view of the above-mentioned problems of the prior art, and its purpose is as follows.
(1) It is easy to control the shape of a microstructure such as a lens,
(2) It can be manufactured relatively inexpensively,
(3) It is possible to easily eliminate unused areas between microstructures such as adjacent lenses.
An object of the present invention is to provide a micro structure array which is a mold for a micro structure array such as a micro lens array, and a manufacturing method thereof.
[0015]
[Means and Actions for Solving the Problems]
A method for producing a microstructure array such as a mold for a microlens array of the present invention that achieves the above object
(1) a step of patterning a thermoplastic material layer on a substrate in a desired shape according to the arrangement of a desired microstructure array;
(2) a step of deforming the patterned thermoplastic material layer by a heat treatment in a discrete state;
(3) On the deformed thermoplastic material layer surface and the substrateElectroless plating or chemical deposition (CVD) Until there is no plane between adjacent thermoplastic layers,Continuous filmIsotropicForming the step.
[0016]
In this manufacturing method, in the step (3), in the arrangement region for the micro structure array, the continuous film is easily formed until the adjacent micro structures are connected to each other and there is no plane portion between the micro structures. Therefore, an unused area between microstructures such as adjacent lenses can be easily eliminated. Of course, it is possible to leave a plane portion between the microstructures if desired. At the same time, since adjacent thermoplastic material layers do not come into contact with each other by reflow, the problem that the desired microstructure shape cannot be maintained due to surface tension is solved, and the yield is improved. In addition, since a continuous film such as a plating layer is formed over the substrate and the thermoplastic material layer, the in-plane distribution of the size of the microstructure array can be reduced if necessary, and the thermoplastic material layer is firmly fixed to the substrate. As a result, the structure becomes stronger.
[0018]
In the step (1), the patterned thermoplastic material layer may be formed in a cylindrical shape, a line shape, a polygonal column such as a quadrangular column or a hexagonal column. Further, a plurality of types of patterned thermoplastic material layers may be formed, or all may be formed identically. Further, the patterned thermoplastic material layers may be regularly arranged such that they are arranged at equal intervals in the left-right and up-down directions, or may be arranged irregularly. What is necessary is just to determine these suitably according to a use.
[0019]
In the step (1), the thermoplastic material layer may be a resin layer such as a photoresist or a metal plating layer. These may be formed by a manufacturing method corresponding to the material, as will be described later. In addition, the shape of the thermoplastic material layer that is deformed by heat treatment can be appropriately controlled by appropriately water-repellent treatment of the substrate surface before forming the thermoplastic material layer.
[0020]
In the step (1), a thermoplastic material layer for the alignment marker structure may be formed also in the alignment marker region outside the arrangement region for the microstructure array. As a result, the alignment marker structure can be formed at an appropriate position, and a microlens array including the alignment marker can be manufactured with a high yield.
[0021]
The microstructure array is typically manufactured as a microstructure array mold or a microlens array mold.
[0024]
The above are the basic and more specific components of the present invention, and the details and operations thereof will be further described below along with typical examples.
[0025]
A typical example of a method for producing a mold for a microstructure array, which is typically a microlens array, is shown. Here, the term “microlens” or “microlens array” refers to a microstructure. Of course, what is described here can also be applied to other methods for manufacturing a mold for a microstructure array.
[0026]
As the substrate material of the present invention, glass, quartz, ceramics, resin, metal, crystal material and the like can be used. Next, the thermoplastic material layer is patterned according to the arrangement with each lens in the microlens array. As the thermoplastic material, photoresist, glass, metal or the like can be used, but it is necessary to select a material having a softening point temperature lower than that of the substrate to be used.
[0027]
As a patterning method, a thermoplastic material layer is formed on a substrate, and typically, the thermoplastic material layer is etched and patterned according to a desired lens pitch and number by semiconductor photolithography and etching. Here, if a photoresist is used for the thermoplastic material layer, the etching step can be omitted. At the same time, an alignment marker pattern can be formed. Further, if the patterning of the thermoplastic material layer is performed in a line shape, a mold for a lenticular lens can be formed.
[0028]
In addition, a photoresist or the like is patterned as a mask layer on a conductive substrate or a substrate on which an electrode layer is formed, a plating layer is formed on the exposed conductive portion, and the plating layer is patterned by removing the mask layer. You can also. A method of dropping small droplets of thermoplastic material on a substrate according to a desired pattern may be used.
[0029]
Next, by performing a reflow process at a temperature equal to or higher than the heat distortion temperature on the patterned thermoplastic material layer, the scattered thermoplastic material layer has a substantially spherical shape or surface due to its heat deformability and surface tension. Deforms into a cylindrical surface shape. Here, if the surface energy of the substrate (which is reduced by the water repellent treatment, the thermoplastic material is repelled more strongly) and the thickness of the thermoplastic material layer are controlled, the shape of the thermoplastic material can be freely adjusted. And the curvature can be controlled. In this state, a plane portion exists between the adjacent microstructures of the thermoplastic material.
[0030]
Next, a continuous film is formed on the thermoplastic material layer and the substrate until there is no planar portion between the microstructures of the thermoplastic material. This eliminates the planar portion between adjacent thermoplastic microstructures (typically hemispherical) formed by patterning. If this is used as a mold for a microlens array, a microlens array with high light utilization efficiency can be obtained. Here, the continuous film is a plating layer, a chemical deposition layer (CVD layer), a vacuum deposition layer, an electrodeposition layer (the electrodeposition liquid is an electrodepositable organic compound (anionic electrodeposition acrylic acid resin, cation type electrode). Any of the above-mentioned electrodeposition liquids such as epoxy resin for deposition) may be used.
[0031]
When electroplating is used as a method for forming a continuous film plating layer, it is necessary to form an electrode layer on the resin surface or the substrate and the substrate, but when electroless plating is used, this is not necessary. In plating, the curved surface shape can be easily controlled by controlling the plating time and the plating temperature. Examples of main plating metals include Ni, Au, Pt, Cr, Cu, Ag, and Zn for single metals, and Cu—Zn, Sn—Co, Ni—Fe, and Zn—Ni for alloys. Any material that can be plated can be used.
[0032]
If it is desired to maintain the curvature of the profile obtained by the reflow process of a thermoplastic material such as a resin, the method of forming a continuous film is preferably electroless plating or chemical deposition, in which isotropic layer growth is performed. . Again, the shape and curvature of the thermoplastic microstructure can be controlled freely by controlling the thickness of the continuous film.
[0033]
The mold for the microlens array is obtained by forming a mold material on the mold master (original) for the microlens array and then peeling the mold (depending on the material of each part, the structure described above may be used as it is. It can also be used as a micro structure array such as a lens array). Since the microlens array mold can be formed directly from the above-mentioned original plate, it does not require expensive equipment and can be manufactured at low cost. As a peeling method, the original and the substrate may be mechanically peeled off. However, since it may be deformed at the time of peeling when it is enlarged, a method of sequentially removing the substrate, the thermoplastic material layer, and the continuous film from the back surface may be taken.
[0034]
In the case where the mold is formed after providing the sacrificial layer on the continuous film, the mold and the substrate can be separated by removing the sacrificial layer. In this case, a material for the sacrificial layer is selected so that the mold is not corroded by the etchant for etching the sacrificial layer. When the continuous film and the substrate are not corroded by the etchant for etching the sacrificial layer, the substrate on which the continuous film is formed can be used a plurality of times as an original plate. If the original becomes unusable due to scratches, dirt, etc. due to multiple use, a mold master may be produced by the same method.
[0035]
As a material for the mold for the microlens, any material such as a resin, a metal, and an insulator can be used as long as it can be formed on a substrate on which a continuous film is formed and can be peeled off. As a simple mold forming method, a solution in which a resin, metal, or glass is melted or dissolved is applied on a substrate on which a continuous film is formed, and after this is cured, it is peeled and formed by the peeling method described above. . In this case, a material that does not alloy the substrate or the continuous film is selected as the mold material. As another method, an electrode layer is formed on a continuous film using a substrate as a cathode, and a mold is electroplated. If a sacrificial layer is used, a mold electrode layer is formed on the sacrificial layer, and electroplating is performed using the mold electrode layer as a cathode.
[0036]
Furthermore, a microlens array can be formed by forming a material to be a microlens on the microlens array mold and then peeling it off. This makes it possible to easily produce microlenses having the same shape at low cost. As the material of the microlens, a material that is easily peelable from the microlens mold is used. When resin is used as the microlens material, light transmissive thermosetting resin, UV curable resin, electron beam curable resin, etc. are applied on the mold for microlens array and then cured by UV light irradiation, electron beam irradiation, etc. Let During curing, no bubbles are formed. When applying the resin, it is preferable to deaerate.
[0037]
After curing, the resin is peeled from the mold to form a microlens array. As the resin for forming the microlens array, a material capable of transmitting light in the wavelength region of light used by the light receiving or light emitting device using the microlens is used. In the case of producing a microlens by the above method, alkali glass is not essential, and the restrictions on the materials of the microlens and the support substrate can be reduced as compared with the ion exchange method. If molten glass is used instead of resin, a glass microlens array can be produced.
[0038]
Of course, the mold of the present invention can be used for manufacturing any structure, not limited to the microlens array, if applicable.
[0039]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments and examples of the present invention will be described below in detail with reference to the drawings.
[0040]
(First embodiment)
The first embodiment is a first aspect of the method for manufacturing a microlens array mold according to the present invention. The manufacturing method will be described with reference to FIGS.
[0041]
First, a water-repellent surface is formed on a 4-inch φ silicon substrate 1 by surface treatment with a silane coupling agent having a functional group having fluorine. Next, a resin layer 2 as a thermoplastic material layer made of a positive resist is applied by spin coating to a thickness of 8 μm (FIG. 1A).
[0042]
Thereafter, 1064 × 808 cylindrical resist patterns 2 are formed at a distance of 18 μm from adjacent patterns using semiconductor photolithography (FIG. 1B).
[0043]
Next, the substrate is baked at 150 ° C. for 15 minutes to reflow the resin layer 2 to form a resin layer 2 having a spherical shape (FIG. 1C). At this time, the contact angle between the resin spherical surface and the substrate 1 was 80 degrees.
[0044]
After cooling, the substrate is immersed in a conditioner solution and then immersed in a catalyst solution containing a palladium-tin colloid to form catalyst nuclei on the surface of the substrate 1 and the resin 2.
[0045]
Next, electroless plating is performed at 90 ° C. using an electroless nickel plating solution (S-780, manufactured by Nippon Kanisen Co., Ltd.). The electroless plating is performed until the plating layer 3 is formed on the surface of the substrate 1 and the resin 2 and there is no plane portion between the adjacent spherical microstructures. In this case, since the electroless plating layer 3 was laminated isotropically, the curvature of the resin 2 formed after reflow was maintained, and the radius of curvature was 15 μm.
[0046]
As a result, 1064 × 808 microlens array molds 4 are obtained. (See FIG. 1 (d)).
[0047]
Next, a release layer 5 is formed by applying an electroforming mold release agent on the electroless plating layer 3 (FIG. 2A). Using this substrate as a cathode, a Ni plating bath composed of nickel sulfamate, nickel bromide, boric acid and a brightening agent was used. The bath temperature was 50 ° C., the cathode current density was 5 A / dm.²Then, Ni electroplating is performed to form the electroformed layer 6 (FIG. 2B). Thereafter, the electroformed layer 6 is released from the substrate to form a microlens array mold 7. As a result, 1064 × 808 molds 7 for a microlens array were obtained. (See FIG. 2 (c)).
[0048]
A microlens array is produced using this mold 7. After a UV curable resin is applied to the microlens array mold 7, a glass substrate serving as a support substrate is placed thereon. The resin was cured by ultraviolet irradiation and then peeled off to produce 1064 × 808 convex microlens arrays. The convex microlens array obtained here did not have a light unused area because there was no plane part between adjacent lens spherical surfaces. Further, the curvature of the lens spherical surface coincided with the curvature of the resin 2 formed after the reflow, and the lens curvature radius was 15 μm.
[0049]
(Second embodiment)
The present embodiment is a second aspect of the method for manufacturing a microlens array mold according to the present invention. Similar to the first embodiment, the manufacturing method will be described with reference to FIGS.
[0050]
The process is the same as in the first embodiment until the resin layer 2 is reflowed to form a spherical resin layer 2 (see FIG. 1C). However, at this time, the contact angle between the resin spherical surface and the substrate 1 is 85 degrees. This angle is larger than that of the first example and is closer to a hemispherical surface (the contact angle is 90 degrees at this time), which indicates that the resin layer 2 is higher than the spherical resin layer 2 of the first example. This control is performed by controlling the surface energy of the substrate as described above.
[0051]
Further, similarly to the first embodiment, after cooling, the substrate is immersed in a conditioner solution, and then immersed in a catalyst solution containing a colloid of palladium-tin to form catalyst nuclei on the surfaces of the substrate 1 and the resin 2. Next, electroless plating is performed at 90 ° C. using an electroless nickel plating solution (S-780, manufactured by Nippon Kanisen Co., Ltd.). The electroless plating is performed until the plating layer is formed on the surface of the substrate 1 and the resin 2 and there is no plane portion between the adjacent spherical surfaces. In this case, since the electroless plating layer 3 was isotropically laminated, the curvature of the resin 2 formed after the reflow was maintained, and the radius of curvature was 14 μm. This value is slightly smaller than that of the first embodiment. As a result, 1064 × 808 microlens array molds 4 are obtained. (See FIG. 1 (d)).
[0052]
The subsequent steps are performed in the same manner as in the first embodiment, and 1064 × 808 molds for microlens array are obtained (see FIG. 2C).
[0053]
By using this mold 7 to produce a microlens array in the same manner as in the first example, 1064 × 808 convex microlens arrays could be produced. The convex microlens array obtained here also has no unused area of light because there is no planar portion between adjacent lens spherical surfaces. Here again, the curvature of the lens spherical surface coincided with the curvature of the resin 2 formed after reflow, and the lens curvature radius was 14 μm.
[0054]
(Third embodiment)
In the third embodiment, a resin layer 2 made of a positive resist is applied on a 4-inch φ silicon substrate 1 by spin coating to a thickness of 8 μm (see FIG. 1A).
[0055]
Thereafter, 1064 × 808 square resist patterns having a side of 16 μm are formed at a distance of 2 μm from adjacent patterns using semiconductor photolithography. At the same time, a pattern for alignment markers is formed at an arbitrary position around it.
[0056]
Next, the resin layer 2 is reflowed by baking the substrate at 150 ° C. for 15 minutes to form a resin layer 2 having a spherical shape (see FIG. 1C).
[0057]
On top of this, 50A and 1000A of chromium and gold are deposited by electron beam evaporation to form an electrode layer. Using this substrate as a cathode, using Ni plating along nickel sulfate, nickel chloride, boric acid and brightener, bath temperature 60 ° C., cathode current density 5 A / dm²Ni plating is performed. The plating layer 3 was formed on the electrode layer, and the plane portion between the adjacent spherical surfaces was lost. As a result, 1064 × 808 microlens array molds having an alignment marker structure were obtained (see FIG. 1D).
[0058]
Next, a release layer 5 is formed on the plating layer 3 by applying an electroforming release agent (see FIG. 2A). Using this substrate as a cathode, a Ni plating bath composed of nickel sulfamate, nickel bromide, boric acid and a brightening agent was used. The bath temperature was 50 ° C., the cathode current density was 5 A / dm.²Then, Ni electroplating is performed to form the electroformed layer 6 (see FIG. 2B). Thereafter, the electroformed layer 6 is modeled from the substrate to form a microlens array mold 7 (see FIG. 2C). Thus, 1064 × 808 microlens array molds 7 having alignment markers were obtained.
[0059]
Again, the microlens array is fabricated as follows. After a UV curable resin is applied to the microlens array mold 7, a glass substrate serving as a support substrate is placed thereon. 1064 × 808 convex microlens arrays having alignment markers could be produced by peeling after curing the resin by ultraviolet irradiation. The convex microlens array obtained here also has no unused area of light because there is no planar portion between adjacent lens spherical surfaces.
[0060]
Subsequently, each microlens could be arranged at a position corresponding to each pixel by attaching the marker of the convex microlens array to the marker formed on the TFT liquid crystal substrate. When these were connected to a drive circuit and driven as a liquid crystal projector, incident light was collected by a microlens and a bright display image could be obtained.
[0061]
(Fourth embodiment)
A fourth embodiment will be described with reference to FIGS. 1, 2, and 4.
[0062]
In the fourth embodiment, first, a resin layer 2 made of a positive resist is applied on a 5-inch φ silicon substrate 1 by spin coating to a thickness of 8 μm. Thereafter, by using semiconductor photolithography, 1064 × 808 regions each having a square resist pattern with a side of 16 μm and an interval between adjacent patterns of 2 μm are formed at intervals of 1.8 mm in the same plane. At this time, an alignment marker pattern is also formed at an arbitrary position outside the 1064 × 808 region as a marker structure used for alignment such as bonding.
[0063]
Next, the substrate is baked at 150 ° C. for 15 minutes to reflow the resin layer 2 to form the resin layer 2 having a spherical shape. After cooling, the substrate is immersed in a conditioner solution and then immersed in a catalyst solution containing a palladium-tin colloid to form catalyst nuclei on the surface of the substrate 1 and the resin 2.
[0064]
Next, electroless plating is performed at 90 ° C. using an electroless nickel plating solution (S-780, manufactured by Nihon Kanisen Co., Ltd.) to form the plating layer 3 on the surface of the substrate 1 and the resin 2. The plane part between adjacent spherical surfaces is eliminated. In this case, since the electroless plating layer 3 is isotropically laminated, the curvature of the resin 2 formed after the reflow is maintained. As a result, a microlens array mold having eight alignment marker structures 8 and 1064 × 808 patterns in the same plane was obtained (see FIG. 4). In FIG. 4, four alignment marker structures 8 are formed at the four corners of each of the 1064 × 808 patterns.
[0065]
Next, the template layer 5 is formed by applying an electroforming mold release agent on the plating layer 3. Using this substrate as a cathode, a Ni plating bath composed of nickel sulfamate, nickel bromide, boric acid and a brightening agent was used. The bath temperature was 50 ° C., the cathode current density was 5 A / dm.²Ni electroplating is performed to form the electroformed layer 6. Thereafter, the electroformed layer 6 is released from the substrate to form a microlens array mold 7. As a result, a microlens array mold having eight alignment marker structures 8 and 1064 × 808 hemispherical microstructure patterns in the same plane was obtained.
[0066]
The convex microlens array is manufactured as follows. After the ultraviolet curable resin is applied to the microlens array mold, a glass substrate to be a support substrate is placed thereon. After the resin was cured by irradiation with ultraviolet rays, it was peeled off and cut into each microlens array, whereby eight convex microlens arrays could be produced from one mold.
[0067]
(5th Example)
A fifth embodiment will be described with reference to FIGS. In the fifth embodiment, first, a resin layer 2 made of a positive resist is applied on a 4-inch φ silicon substrate 1 by spin coating to a thickness of 8 μm. Thereafter, by using semiconductor photolithography, a square resist pattern having a side of 16 μm is formed with 1064 × 808 square resist patterns with an interval of 2 μm, and a square resist pattern with a side of 14 μm is spaced from the adjacent pattern. Three types of 1064 × 808 formed at 4 μm and a square resist pattern of 12 μm on a side and 1064 × 808 formed at an interval of 6 μm between adjacent patterns are formed on the same plane at 1.8 mm intervals one by one. Form.
[0068]
Next, the resin layer 2 is reflowed by baking the substrate at 150 ° C. for 15 minutes to form a resin layer 2 having a spherical shape. After cooling, the substrate is immersed in a conditioner solution and then immersed in a catalyst solution containing a palladium-tin colloid to form catalyst nuclei on the surfaces of the substrate 1 and the resin 2.
[0069]
Next, electroless plating is performed at 90 ° C. with an electroless nickel plating solution (S-780, manufactured by Nihon Kanisen Co., Ltd.), whereby the plating layer 3 is formed on the surfaces of the substrate 1 and the resin 2 and adjacent to each other. The plane part between the spherical surfaces is eliminated. In this case, since the electroless plating layer was isotropically laminated, the curvature of the resin 2 formed after the reflow was maintained. As a result, a microlens array mold having 1064 × 808 patterns each having three kinds of curvatures in the same plane was obtained.
[0070]
Next, the template layer 5 is formed by applying an electroforming mold release agent on the plating layer 3. Using this substrate as a cathode, a Ni plating bath composed of nickel sulfamate, nickel bromide, boric acid and a brightening agent was used. The bath temperature was 50 ° C., the cathode current density was 5 A / dm.²Ni electroplating is performed to form the electroformed layer 6.
[0071]
Thereafter, the electroformed layer 6 is released from the substrate to form a microlens array mold 7. As a result, a microlens array mold having 1064 × 808 patterns each having three kinds of curvatures in the same plane was obtained.
[0072]
After the ultraviolet curable resin is applied to the microlens array mold, a glass substrate to be a support substrate is placed thereon. After the resin was cured by ultraviolet irradiation, it was peeled off and cut into each microlens array, whereby a convex microlens array having three types of curvature could be produced from one mold.
[0073]
【The invention's effect】
As described above, according to the present invention, it is easy to control the manufacturing process, the shape of a microstructure such as a lens, and there is no unused area of light between the lenses. A microstructure array and a manufacturing method thereof could be provided. Moreover, a plurality of or a plurality of types of microstructure structures such as a microlens array mold could be formed on one substrate surface.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a part of a manufacturing process of a microlens array mold of the present invention.
FIG. 2 is a cross-sectional view showing a part of a manufacturing process of a microlens array mold of the present invention.
FIG. 3 is a top view showing a microlens array mold of the present invention.
FIG. 4 is a top view of a microlens array mold according to a fourth embodiment of the present invention.
[Explanation of symbols]
1 Substrate
2 Thermoplastic material layer
3 Continuous film
4 Mold
5 Release layer
6 Electroformed layer
7 Mold
8 Alignment marker

Claims (1)

A method for manufacturing a microstructure array, comprising: (1) a step of patterning a thermoplastic material layer on a substrate in a desired shape in accordance with a desired array of microstructure arrays; and (2) the patterning in a discrete state. A step of deforming the thermoplastic material layer by heat treatment; (3) a plane portion between adjacent thermoplastic material layers by electroless plating or chemical deposition (CVD) on the deformed thermoplastic material layer surface and the substrate; A process for forming a continuous film isotropically until there is no more.