JP3681101B2 - Manufacturing method of mold master for microlens array - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a microlens array for producing a microlens array used in the field of optoelectronics.Mold master production methodIt is about.
[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 is becoming like.
[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 further 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 future of optical parallel processing / calculation, optical interconnection, and the like, which are expected to be optical information processing fields.
[0006]
In addition, research and development of self-luminous display devices such as electroluminescence (EL) have been actively conducted, and high-definition and high-luminance displays have been proposed. In such a display, there is a demand for a low-cost, large-area microlens array in addition to a small-sized and large numerical aperture microlens array.
[0007]
Under the circumstances as described above, conventionally, a plurality of substrates on a multi-component glass substrate using an ion exchange method (M. Oikawa, et al., Jpn. J. Appl. Phys. 20 (4) L51-54, 1981) are used. There is known a method of manufacturing a microlens array in which a plurality of lenses are formed by increasing the refractive index of the portion. However, with this method, the lens diameter cannot be made larger than the distance between the lenses, and it is difficult to design a lens with a large numerical aperture. 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.
[0008]
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. In addition, it is originally known that the ion exchange method on the glass surface leaves a compressive strain on the surface. As the glass warps and the microlens array becomes large, it is bonded and bonded to the light receiving device and the light emitting device. Has become difficult.
[0009]
As another method, there is a registry flow method (D. Daly, et al., Proc. Microlens Array Teddington., P23-34, 1991). In this method, a resin formed on a substrate is patterned into a cylindrical shape using a photolithography process, and this is heated and reflowed to produce a microlens array. By this method, lenses having various shapes can be manufactured at low cost. Further, there are no problems such as thermal expansion coefficient and warpage as compared with the ion exchange method. However, in this method, the microlens shape strongly depends on the thickness of the resin, the wettability between the substrate and the resin, and the heating temperature. Likely to happen. Further, when adjacent lenses come into contact with each other by reflow, it becomes impossible to maintain a desired lens shape due to surface tension. That is, it is difficult to increase the light collection ratio by bringing adjacent lenses into contact with each other to reduce the light unused area between the lenses.
[0010]
In addition, when trying to obtain a lens diameter of about several tens to several hundreds of micrometers, a resin having a sufficient thickness to be made spherical by reflow is applied, but it has desired optical characteristics (refractive index, high light transmittance). It is difficult to apply the resin material uniformly and thickly. That is, it is difficult to produce a microlens having a large curvature and a large lens diameter.
[0011]
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. 1-223101) and a method of forming 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 hardly generated, and microlenses 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, the electron beam drawing apparatus is expensive and requires a large amount of capital investment. Since the drawing area is limited, it is difficult to produce a master having a large area of 10 cm square or more. There are problems such as.
[0012]
Further, 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.
[0013]
As a method for solving the above problems, a method of producing a hemispherical structure array by electroplating, producing a mold for microlens using this as an original plate, and further producing a microlens array from this mold is devised. (Japanese Examined Patent Publication No. 64-10169). According to this method, a microlens mold can be manufactured easily with a large size, an easy manufacturing process, high controllability, and low cost.
[0014]
[Problems to be solved by the invention]
However, in this method, a distribution occurs in the current density due to the shape of the opening 106 at the time of plating, and as shown in FIG. This promotes an in-plane distribution in the size of the hemispherical structure 108.
[0015]
The present invention has been made in view of the above-described problems of the prior art. Its purpose is (1) easy to enlarge, (2) easy manufacturing process, high controllability, (3) relatively inexpensive, (4) small in-plane distribution, (5) same substrate surface For microlens arrays that can have multiple or multiple types of lens patterns insideMold master production methodIs to provide.
[0016]
[Means and Actions for Solving the Problems]
To achieve the above object, the present inventionMold master for micro lens arrayThe manufacturing method of
(1) A step of preparing a substrate (conductive substrate, substrate having an electrode layer, etc.) having a conductive portion at least in part,
(2) The aboveOn boardForming an insulating first mask layer on the substrate;
(3) forming a plurality of appropriately shaped openings in the first mask layer to expose the conductive portions;
(4) forming a first plating layer on the opening and the first mask layer through the opening by electroplating using the conductive portion as a cathode;
(5) forming an insulating second mask layer on the opening and a selected region of the first plating layer;
(6) removing the first plating layer in the region where the second mask layer is not formed by electrolytic etching by applying a voltage using the conductive portion as an anode;
And after the step (6),
(7) a step of removing the first mask layer entirely after removing the second mask layer;
Or
(8) removing the second mask layer after removing the first mask layer that is not covered by the second mask layer while leaving the second mask layer;
Any of the steps,
(9) forming a second plating layer or electrodeposition layer from the first plating layer to the conductive portion;
Having furtherFeatures.
[0017]
Based on the above basic configuration, the following more specific modes are possible.
After the step (6), (7) a step of removing the second mask layer, (8) a step of completely removing the first mask layer, (9) from the first plating layer to the conductive portion. A step of forming a second plating layer or electrodeposition layer;The method of havingThis corresponds to the first embodiment described later. Since the second layer only needs to be formed smoothly by fixing the first electroplating layer, it can be formed by electroplating, electroless plating, etc. in addition to electroplating (DC plating, pulse plating, etc.). In addition, Al for electroplating bath₂O₃TiO₂Dispersion plating by adding dispersed particles such as PTFE can also be used. The dispersed particles can improve the mechanical strength and corrosion resistance of the convex structure. In electrodeposition, an electrodepositable organic compound (anionic electrodeposition acrylic carboxylic acid resin, cationic electrodeposition epoxy resin, or the like) can be electrodeposited on the first plating layer using an electric current. This is the same in the later embodiments.
[0018]
After the step (6), (7) removing the first mask layer not covered with the second mask layer while leaving the second mask layer, and (8) removing the second mask layer. More steps toThe method of havingThis corresponds to an embodiment shown in FIG. In this case, after the step (8), the method may further include (9) a step of forming a second plating layer or an electrodeposition layer from the first plating layer to the conductive portion. In this aspect, if the first mask layer is formed of a material (PSG or the like) having sufficient adhesion with the conductive portion of the substrate, the second plating layer or electrodeposition layer is not formed.Mold masterCan be used as
[0019]
As described above, the second plating layer can be formed by electroplating or electroless plating for increasing the glossiness. In this case, the second plating layer may be a nickel plating layer or the second nickel plating layer. Some layers contain phosphorus to increase corrosion resistance.
[0020]
The openings may be arranged in a periodic repeating arrangement pattern (such as a two-dimensional matrix arrangement pattern) within the substrate surface. This periodically repeating array pattern is not a unit array pattern that is repeated in it, but it is a uniform array as a whole, and no unit array pattern can be found anywhere. (Conversely, if you try to take a unit, you can get the unit array pattern anywhere.) This is because if there is an array pattern as a unit, the current density is distributed in the pattern, and the electric field concentrates around the array pattern as a unit, causing a problem.
[0021]
In the step (4), the first plating layer may be formed separately. In this way, the first mask layer can be reliably removed when the entire surface is removed.
[0022]
In the step (5), the second mask layer may be formed in a plurality of regions. In this case, in the step (5), the plurality of regions of the second mask layer include a plurality of regions covering the first plating layer of the same arrangement, or the plurality of regions of the second mask layer are A plurality of regions covering the first plating layers in different arrangements can be included.
[0023]
The width of the region of the first plating layer not covered with the second mask layer in the step (5) is preferably 2 mm or more around the region of the first plating layer covered with the mask layer. This can facilitate the in-plane distribution of the diameter of the first plating layer in the region covered with the second mask layer in the step (5) to be within 5%. This realizes sufficient performance as a microlens array.
[0024]
A mode in which a part of the region of the first plating layer covered with the second mask layer is for forming the first plating layer serving as an alignment marker may be employed. This is used as an alignment mark in a later process.
[0025]
The electrolytic etching can be performed in a plating bath as used in step (4).
[0026]
The material of the conductive portion serving as the electrode and the material of the first plating layer formed in the step (4) may be a material that does not form an alloy layer. In this way, unnecessary portions of the first plating layer are completely removed when the first plating layer is removed, so that no protrusion remains, and unnecessary when the second plating layer or electrodeposition layer is formed. Protrusions (things that may be mistaken for alignment markers) are not formed. The material of the conductive portion serving as the electrode and the material of the first plating layer formed in the step (4) do not form an alloy layer by the diffusion of the conductive partial material toward the first plating layer. Even a simple material has the same effect. For example, if the first plating layer is Ni and the conductive portion is Au, the alloy diffuses to the first plating layer side to form an alloy layer, and the alloy is removed when the first plating layer is removed. The layer protrusions will remain.
[0027]
However, the material of the conductive portion serving as the electrode and the material of the first plating layer formed in the step (4) are diffused to the conductive portion side to form an alloy layer. It is good if it is a material that does. Because in this case, the first plating layer diffuses to the conductive portion side to form an alloy layer, so even if the alloy layer remains when the first plating layer is removed, it does not become a protrusion. It is. For example, if the first plating layer is Au and the conductive portion is Ni, Au diffuses to the conductive portion side to form an alloy layer, but this is not a problem.
[0030]
The above are the basic and more specific components of the present invention, and the details and operations thereof will be described below along with typical examples. First, the principle of forming the first plated layer structure such as a hemisphere will be described.
[0031]
When electroplating is performed on a minute opening portion of an insulating mask layer formed on a conductive substrate or a substrate having an electrode layer, first, a plating layer is deposited in the opening portion, and when electroplating is performed, the opening portion and The first plating layer begins to grow on the mask layer. When the size of the opening is sufficiently smaller than the electroplating anode, the first plating layer grows isotropically with respect to the center or center line of the opening, and the first plating layer such as a hemisphere opens. Formed on the portion and the mask layer. By making the shape of the opening circular, the first plating layer can grow isotropically hemispherically on the mask layer.
[0032]
Compared with the method of forming the original plate by etching, if the current flowing between the anode and the cathode is stopped when the desired shape is obtained, the deposition of the plating can be stopped. Such an unexpected shape error can be avoided, and the controllability of production is good.
[0033]
Next, a method for producing a microlens array mold or mold master will be described. First, a first mask layer is formed over a conductive substrate or a substrate having an electrode layer. The substrate material for plating may be any material of metal, semiconductor, and insulator, and it is possible to use a metal plate, a glass substrate, a silicon wafer, etc. with good flatness. If a metal material is used as the plating substrate, it is not necessary to form an electrode layer. Further, in the case of using a semiconductor, it is not always necessary to form an electrode layer as long as it has conductivity that allows electroplating. The electrode layer is selected from materials that are not corroded by the plating solution to be used because it is exposed to the plating solution. However, since the first plating layer formed on this electrode layer is removed by electrolytic etching in a later step, a material that does not form an alloy layer with the first plating layer is preferable.
[0034]
The electrode layer is preferably made of a material that is not electrolytically etched even in the plating solution. The first mask layer only needs to be an insulating material, and either an inorganic insulator or an organic insulator can be used. As a method for forming the electrode layer and the first mask layer, a thin film forming method such as a vacuum deposition method, a spin coating method, a dip method, or a chemical deposition method (CVD) is used.
[0035]
Next, an opening array is formed in the first mask layer. The opening shape is preferably circular. In forming the opening, the opening is formed by a semiconductor photolithography process and etching capable of forming a minute opening. When a photoresist is used as the first mask layer, the etching process can be omitted.
[0036]
Next, the plating substrate is immersed in a plating solution containing metal ions, and an external power source is connected between the anode plate and the anode plate to form a first plating layer in the opening. Plating is formed in the opening, and further plating continues to spread the first plating layer on the first mask layer to form a hemispherical structure. The diameter of the microlens formed by the microlens array mold or the mold master to be manufactured is in the range of several μm to several hundred μm. Therefore, the size of the opening is the desired microlens array mold or mold It is necessary to make it smaller than the diameter of the microlens formed by the mold master. In order for the plating growth to be isotropic, the shape of the hemispherical structure approaches a true sphere as the size of the opening is smaller than the diameter of the hemispherical structure. The hemispherical structure is formed by precipitation of metal ions in the plating bath by an electrochemical reaction.
[0037]
In electroplating, it is possible to easily control the thickness of the first plating layer by controlling the plating time and the plating temperature. As the main plating metal, Ni, Au, Pt, Cr, Cu, Ag, Zn, etc. can be used for single metals, and Cu—Zn, Sn—Co, Ni—Fe, Zn—Ni, etc. can be used for alloys. It is. Any other material that can be electroplated can be used, but a material that does not form an alloy layer with the electrode layer is preferable.
[0038]
In the first plating layer formed here, the peripheral portion of the array grows larger than the central portion. This is because the current distribution is not uniform and the current concentrates at the end of the electrode. However, in the method of the present invention, the first plating layer grown larger than the central portion of the peripheral portion of the array is selectively removed by electrolytic etching to obtain an array of the first plating layer having a substantially uniform size. Can do.
[0039]
That is, the method forms the second mask layer on the region where the first plating layer having a substantially uniform size is formed. The second mask layer only needs to be an insulating material, and either an inorganic insulator or an organic insulator can be used. As a method for forming the insulating layer of the second mask layer, a thin film forming method such as a vacuum deposition method, a spin coating method, or a dip method is used. In forming an insulating layer only in a selective region, it is formed by a semiconductor photolithography process and etching. When a photoresist is used as the second mask layer, the etching process can be omitted.
[0040]
Next, using this substrate as a workpiece, the substrate is dipped in a plating solution on which the first plating layer has been formed, and a cathode and an anode are connected to flow current from an external power source, contrary to the case where the first plating layer is formed. As a result, the first plating layer grown larger than the central portion is selectively removed by electrolytic etching. If the electrode layer is a material that is not electrolyzed with the plating solution and does not form an alloy layer with the first plating layer, a flat surface of the electrode layer can be obtained after electrolytic etching.
[0041]
The first plating layer covered with the remaining second mask layer has a substantially uniform size and a hemispherical structure array with a small in-plane diameter distribution. The metal of the first plating layer removed here can be recovered in the plating solution or on the counter electrode metal plate, and even an expensive metal material can be used without waste.
[0042]
Furthermore, if the second mask layer is formed on the first plating layer existing at an arbitrary position, it is possible to form an alignment marker made of the first plating layer without being subjected to electrolytic etching in the subsequent process. It becomes. At this time, if a part of the plating layer to be removed is exposed in the plating solution, it can be removed by electrolytic etching.
[0043]
Further, in this method, by providing a plurality of second mask layers in the substrate, a microlens array having a small in-plane distribution of diameters of a plurality of or a plurality of types of first plating layers from one substrate. It is also possible to obtain a metal mold or a mold master. That is, after the first plating layer is formed, the second mask layer is selectively formed in a region having a small in-plane distribution of the diameter of the first plating layer excluding the peripheral portion of the array pattern. Because you can.
[0044]
Next, the first and second mask layers are removed, and a second plating layer is formed from the first plating layer to the electrode layer. As a result, the first plating layer is firmly fixed on the electrode layer, and the first plating layer can be prevented from falling off in subsequent steps, and the durability of the microlens array mold or mold master is improved. Become.
[0045]
The microlens array mold is obtained by forming a mold material on the microlens array mold master (original) and then peeling the mold. Since the microlens array mold can be formed directly from an original plate formed by electroplating, 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 the size is increased, a method of sequentially removing the substrate, the electrode layer, and the first and second plating layers from the back surface may be taken.
[0046]
In the case where the mold is formed after providing the sacrificial layer on the substrate and the second plating layer, 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 first and second plating layers and the substrate are not corroded by the etchant that etches the sacrificial layer, the substrate on which the first and second plating layers are formed can be used a plurality of times as a master, However, when it becomes unusable due to scratches, dirt, etc. due to multiple use, a mold can be easily produced by the same method.
[0047]
As a material for the microlens mold, any material such as a resin, a metal, and an insulator can be used as long as it can be formed on the substrate on which the first and second plating layers are formed and can be peeled off. .
[0048]
As a simple mold forming method, a molten or dissolved solution of resin, metal, or glass is applied on the substrate on which the first and second plating layers are formed and cured, and then peeled by the peeling method described above. To form. In this case, a material that is not alloyed with the substrate or the second plating layer is selected as the mold material.
[0049]
As another method, a mold is electroplated on the second plating layer and the electrode layer of the substrate using the substrate as a cathode. 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.
[0050]
Further, 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 me. During curing, no bubbles are formed. When applying resin, it is good to deaerate. After curing, the resin is peeled from the mold to form a microlens array. As the resin that becomes the microlens array, a light-transmitting material using a microlens or a material that can transmit light in the wavelength region of light used by the light-emitting device is used.
[0051]
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.
[0052]
Of course, the mold of the present invention is not limited to the microlens array as long as it can be applied, and can be used for manufacturing any structure.
[0053]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the invention will be described below with reference to the drawings.
[0054]
(First embodiment)
The first embodiment is a first aspect of a method for manufacturing a microlens array mold or mold master and a microlens array according to the present invention. The manufacturing method will be described with reference to FIG.
[0055]
The manufacturing process will be described with reference to FIGS. A silicon wafer having a diameter of 2 inches and having a silicon dioxide film with a thickness of 1 μm formed on both sides by using an oxidizing gas is used as the substrate 1 shown in FIG. An electrode layer 2 is formed on the wafer 1 by continuously forming 50 and 500 nm of Ti and Pt respectively by a vacuum sputtering method which is one of thin film forming methods. A positive photoresist (Az1500: manufactured by Hoechst) is applied thereon to form the first mask layer 3.
[0056]
Next, a photoresist is formed on the first mask layer 3, the photoresist is exposed and developed by photolithography, and is etched using the photoresist as a mask to partially expose the electrode layer 2. Form. The opening 4 has a circular shape with a diameter of 5 μm and a distance between adjacent openings 4 of 25 μm. In this example, a total of 860 × 860 openings 4 were provided (see FIG. 1A).
[0057]
Using the substrate 1 as a workpiece, the electrode layer 2 as a cathode, a Ni plating bath composed of nickel sulfate, nickel chloride, boric acid and a brightener, bath temperature 60 ° C., cathode current density 40 A / dm²Ni plating is performed. The first plating layer 6 made of Ni is first deposited and grown from the opening 4, and the first plating layer 6 spreads on the first mask layer 3, and a hemispherical structure having a radius of about 10 μm at the center of the array. The first plating layer 6 was grown until the body 8 was formed (see FIG. 1B).
[0058]
2A and 2B are diagrams showing the in-plane distribution of the hemispherical structure 8 in FIG. 1B, in which FIG. 2A is a cross-sectional view and FIG. 2B is a top view. When the radius of the hemispherical structure 8 was about 10 μm in the center of the array, the hemispherical structure 8 having a maximum radius of about 15 μm was formed in the array peripheral part 5.
[0059]
Next, a positive photoresist (AzP4620: manufactured by Hoechst) is applied, exposed, and developed, and the second mask layer 7 is selectively applied to 700 × 700 areas excluding the 2 mm width of the array peripheral portion 5. Provide. As a result, the first plating layer 6 in the array peripheral portion 5 was exposed (FIG. 1C). 3A is a cross-sectional view, and FIG. 3B is a top view. Here, the in-plane distribution of the diameter of the first plating layer 6 in the region covered with the second mask layer 7 was within 5%.
[0060]
Using this substrate 1 as a work, using it as an anode, a Ni plating bath made of nickel sulfate, nickel chloride, boric acid and a brightener, bath temperature 60 ° C., anode current density 8 A / dm²Then, the exposed first plating layer 6 is subjected to electrolytic etching (FIG. 1D). Here, since Pt is used as the electrode layer 2, the electrode layer 2 is not corroded. Then, the electrolytic etching was stopped when the first plating layer 6 made of Ni existing in the region not covered with the second mask layer 7 was consumed.
[0061]
Next, by removing the first and second mask layers 3 and 7 with acetone and dimethylformamide, a hemispherical structure array having 700 × 700 hemispherical structures 8 can be formed (see FIG. 1 (e)). 4A and 4B are diagrams showing the in-plane distribution of the hemispherical structure 8 in FIG. 1E. FIG. 4A is a cross-sectional view and FIG. 4B is a top view. The in-plane distribution of the radius of the hemispherical structure 8 was within 5%.
[0062]
Next, using the electrode layer 2 as a cathode, a Ni plating bath composed of nickel sulfate, nickel chloride, boric acid and a brightener is used, the bath temperature is 60 ° C., the cathode current density is 8 A / dm.²Then, Ni plating is performed to form the second plating layer 9 (FIG. 1 (f)). Thus, a microlens array mold or mold master in which the first plating layer 6 is firmly fixed on the electrode layer 2 is obtained.
[0063]
As described above, according to this example, in the microlens array mold or the mold master, it was possible to provide a manufacturing method capable of easily reducing the in-plane distribution of the size of the hemispherical structure.
[0064]
Next, a process of making a mold using the structure formed by the above manufacturing method as a master will be described. A sacrificial layer 10 is formed by depositing 1 μm of PSG (Phosphoric acid glass) at 350 ° C. by atmospheric pressure CVD (Chemical Vapor Deposition) method (FIG. 5A). Subsequently, Ti and Au are successively deposited by 10 nm and 200 nm, respectively, by an electron beam vapor deposition method to form the mold electrode layer 11 (FIG. 5B).
[0065]
Using this mold as a workpiece, using the mold electrode layer 11 as a cathode, using a Ni plating bath composed of nickel sulfamate, nickel bromide, boric acid and brightener, bath temperature 50 ° C., cathode current density 5 A / dm²Then, Ni electroplating is performed to form the mold 20 (FIG. 5C).
[0066]
Next, the substrate is immersed in a mixed aqueous solution of hydrofluoric acid and ammonium fluoride to remove PSG as the sacrificial layer 10 by etching, and the substrate and the mold 20 are peeled off. At this time, Ti in the mold electrode layer 11 is also removed. Thereafter, Au in the mold electrode layer 11 is removed by etching with a mixed aqueous solution of iodine and potassium iodide to form a convex microlens array mold 20 (FIG. 5D).
[0067]
A microlens array is manufactured using this mold 20. After the ultraviolet curable resin 12 is applied to the convex microlens array mold 20, a glass substrate to be the support substrate 13 is placed thereon (FIG. 5E). A convex microlens array 15 was produced by peeling the resin 12 after being cured by ultraviolet irradiation (FIG. 5F). Also in this convex microlens array, the in-plane distribution of the lens diameter was within 5%.
[0068]
(Second embodiment)
A second embodiment will be described with reference to the manufacturing process diagrams of FIGS. 1 and 5 to 9. The process until the opening 4 shown in FIG. 1A is formed is the same as in the first embodiment. In the second embodiment, the interval between the adjacent openings 4 is 18 μm. In this example, 2000 × 2000 openings 4 were provided as a whole (see FIG. 1A). The process of growing the first plating layer 6 until the hemispherical structure 8 having a radius at the center of the array of about 10 μm is performed in the same manner as in the first embodiment (see FIG. 1B).
[0069]
2A and 2B are diagrams showing the in-plane distribution of the hemispherical structure 8 in FIG. 1B, in which FIG. 2A is a cross-sectional view and FIG. 2B is a top view. When the radius of the hemispherical structure 8 was about 10 μm at the center of the array, the hemispherical structure 8 having a maximum radius of about 15 μm was formed at the array periphery 5.
[0070]
Next, a second mask layer 7 made of a positive photoresist (AzP4620: manufactured by Hoechst) is formed. The photoresist applied on the second mask layer 7 is exposed and developed, and the second mask layer 7 is selectively provided in 1064 × 806 regions excluding the array peripheral portion 5 (FIG. 1C). ). Here, in the present embodiment, the second mask layer 7 is formed at any two positions other than the 1064 × 806 regions in order to form the marker 14 used for alignment such as bonding. (FIG. 6).
[0071]
Next, using the substrate 1 as a work, using as a positive electrode a nickel plating bath made of nickel sulfate, nickel chloride, boric acid and a brightener, the bath temperature is 60 ° C., and the anode current density is 8 A / dm.²Then, electrolytic etching of the exposed first plating layer 6 (including a partly exposed layer) is performed. Here, since Pt is used as the electrode layer 2, the electrode layer 2 is not corroded. Then, the electrolytic etching stops when the first plating layer 6 made of Ni existing in the region not completely covered with the second mask layer 7 is consumed.
[0072]
Next, the first and second mask layers 3 and 7 are removed with acetone and dimethylformamide, so that a hemispherical shape having 1064 × 806 hemispherical structures 8 and a marker 14 composed of the first plating layer 6 is obtained. A structure array can be formed. FIG. 7 is a top view, and the in-plane distribution of the radius of the hemispherical structure 8 is within 5%.
[0073]
Here, using an electrode layer 2 as a cathode, a Ni plating bath made of nickel sulfate, nickel chloride, boric acid and a brightening agent, bath temperature 60 ° C., cathode current density 8 A / dm.²Then, Ni plating is performed to form the second plating layer 9. As a result, a microlens array mold or mold master in which the first plating layer 8 (including the marker 14) is firmly fixed on the electrode layer 2 is obtained. The curvature radius of the plating layer 8 in the use area at this time was about 25 μm, and the distribution of the curvature radius was within 5%.
[0074]
As described above, according to the present example, in the hemispherical micro structure array with the marker 14, a manufacturing method capable of easily reducing the in-plane distribution of the size of the hemispherical structure 8 in the use region can be provided. .
[0075]
The convex microlens array mold can be formed in the same manner as in the first embodiment. In this case, a concave marker having an inverted shape of the convex marker 14 is also formed in this mold. After the ultraviolet curable resin 12 is applied to the mold convex microlens array mold, a glass substrate 13 to be the support substrate 13 is placed thereon. A convex microlens array 15 having a convex marker 14 for alignment can be produced by peeling the resin 12 after being cured by ultraviolet irradiation (FIG. 8). Also in this convex microlens array 15, the in-plane distribution of the lens curvature radius was within 5%.
[0076]
Subsequently, by aligning the marker 14 of the convex microlens array 15 with the marker formed on the TFT liquid crystal substrate and pasting them together, the microlens could be arranged at a position corresponding to each pixel. 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.
[0077]
(Third embodiment)
A third embodiment will be described with reference to the manufacturing process diagram of FIG. The process is the same as in the first embodiment until the opening 4 is formed. The openings 4 are provided in an array in a region of 950 mmφ in the silicon wafer surface. Using the substrate 1 as a workpiece, the first plating layer 6 is grown until the hemispherical structure 8 having a radius at the center of the array of about 10 μm is the same as in the first embodiment (FIG. 1B). )reference).
[0078]
Next, a mask layer 7 made of a body-type photoresist (AzP4620: manufactured by Hoechst) is formed (FIG. 1C). The photoresist is exposed and developed, and a second mask layer 7 is selectively provided on the region excluding the peripheral portion 5 of the wafer. Here, four second mask layers 7 are provided in the same plane in 700 × 700 regions.
[0079]
Subsequently, using the substrate 1 as a work, using the Ni plating bath made of nickel sulfate, nickel chloride, boric acid and a brightener as an anode, the exposed substrate was exposed at a bath temperature of 60 ° C. and an anode current density of 8 A / dm 2. Electrolytic etching of one plating layer 6 is performed.
[0080]
Next, by removing the first and second mask layers 3 and 7 with acetone and dimethylformamide, a hemispherical structure array having four 700 × 700 hemispherical structures 8 in the same plane is formed. We were able to. At this time, the in-plane distribution of the radius of the hemispherical structure 8 within each region and between the regions was within 5%.
[0081]
As described above, the present embodiment provides a manufacturing method that can easily reduce the in-plane distribution of the size of the hemispherical structure 8 in a microlens array mold or mold master having a plurality of regions having the same structure. We were able to.
[0082]
Here, a convex microlens array mold can be formed in the same manner as in the first embodiment (see FIGS. 5A to 5D). And after apply | coating the ultraviolet curable resin 12 to the metal mold | die 20 for convex type micro lens arrays, the glass substrate used as the support substrate 13 is set | placed on it, after making it harden | cure by ultraviolet irradiation, it peels, and also cuts off each area | region. Thus, four convex microlens arrays 15 could be produced from one mold 20 (see FIGS. 5E and 5F). In each of the convex microlens arrays 15, the in-plane distribution of the lens diameter was within 5%.
[0083]
(Fourth embodiment)
A fourth embodiment will be described with reference to the manufacturing process diagram of FIG. The process is the same as in the first embodiment until the opening 4 is formed. The openings are provided in an array in a region of 950 mmφ in the silicon wafer surface. Using the substrate 1 as a workpiece, the first plating layer 6 is grown until the hemispherical structure 8 having a radius at the center of the array of about 10 μm is the same as in the first embodiment (FIG. 1B). )reference).
[0084]
Next, a mask layer 7 made of a body-type photoresist (AzP4620: manufactured by Hoechst) is formed (FIG. 1C). The photoresist is exposed and developed, and a second mask layer 7 is selectively provided on the region excluding the peripheral portion 5 of the wafer. Here, the second mask layer 7 is provided with three types of regions in the same plane: the number of the first plating layers 6 is 700 × 700, 1024 × 768, and 700 × 350.
[0085]
Subsequently, using the substrate 1 as a work, using as a positive electrode a nickel plating bath made of nickel sulfate, nickel chloride, boric acid and brightener, the bath temperature is 60 ° C., and the anode current density is 8 A / dm.²Then, the exposed first plating layer 6 is electrolytically etched.
[0086]
Next, by removing the first and second mask layers 3 and 7 with acetone and dimethylformamide, regions of three types of hemispherical structures 8 of 700 × 700, 1024 × 768, and 700 × 350 are obtained. Can be formed in the same plane.
[0087]
At this time, the in-plane distribution of the radius of the hemispherical structure 8 within each region and between the regions was within 5%.
[0088]
As described above, the present embodiment provides a manufacturing method that can easily reduce the in-plane distribution of the size of the hemispherical structure 8 in a microlens array mold or mold master having a plurality of regions having different structures. We were able to.
[0089]
Here, a convex microlens array mold can be formed in the same manner as in the first embodiment (see FIGS. 5A to 5D). And after apply | coating the ultraviolet curable resin 12 to the metal mold | die 20 for convex type micro lens arrays, the glass substrate used as the support substrate 13 is set | placed on it, after making it harden | cure by ultraviolet irradiation, it peels, and also cuts off each area | region. Three types of convex microlens arrays 15 could be produced from one mold 20 (see FIGS. 5E and 5F). In each convex microlens array, the in-plane distribution of the lens diameter was within 5%.
[0090]
(5th Example)
A fifth embodiment will be described with reference to the manufacturing process diagram of FIG. A silicon wafer having a diameter of 4 inches and having a silicon dioxide film with a thickness of 1 μm formed on both sides by using an oxidizing gas is used as the substrate 1 shown in FIG. The electrode layer 2 is formed on this wafer by continuously forming Ti and Ni of 50 mm and 500 mm, respectively, by vacuum sputtering, which is one of the thin film forming methods. On top of this, 1 μm of PSG is formed at 350 ° C. by the atmospheric pressure CVD method to form the first mask layer 3. Here, the adhesion between Ni of the electrode layer 2 and PSG of the first mask layer 3 is strong.
[0091]
Next, a body-type photoresist (Az1500: manufactured by Hoechst) is applied onto the first mask layer 3 by photolithography, exposed, and developed to provide an opening, and by reactive ion etching using carbon tetrafluoride. The mask layer 3 in the opening of the photoresist is removed by etching. Thus, the electrode layer 2 is partially exposed to form the opening 4. The opening 4 has a circular shape with a diameter of 5 μm and a distance between adjacent openings 4 of 25 μm. Further, in this example, 860 × 860 openings 4 were provided as a whole (see FIG. 9A).
[0092]
Using this substrate 1 as a work, using an electrode layer 2 as a cathode and a Ni plating bath made of nickel sulfate, nickel chloride, boric acid and a brightener, bath temperature 60 ° C., cathode current density 40 A / dm²Then, Ni plating is performed. The first plating layer 6 made of Ni is first deposited and grown from the opening 4 and spreads on the first mask layer 3 until the hemispherical structure 8 having a radius at the center of the array of about 10 μm is obtained. One plating layer 6 is grown (see FIG. 9B). When the radius of the hemispherical structure 8 was about 10 μm in the center of the array, the hemispherical structure 8 having a maximum radius of about 15 μm was formed in the array peripheral part 5.
[0093]
Next, a body-type photoresist (AzP4620: manufactured by Hoechst) is applied, exposed, and developed, and the second mask layer 7 is selectively applied to 700 × 700 areas excluding the width of 2 mm of the array peripheral portion 5. Provide. As a result, the first plating layer 6 in the array peripheral portion 5 is exposed (FIG. 9C). Here, the in-plane distribution of the diameter of the first plating layer 6 in the region covered with the second mask layer 7 was within 5%.
[0094]
Subsequently, using the substrate 1 as a work, using as a positive electrode a nickel plating bath made of nickel sulfate, nickel chloride, boric acid and brightener, the bath temperature is 60 ° C., and the anode current density is 8 A / dm.²Then, the exposed first plating layer 6 is electrolytically etched. Here, since Ni is used as the electrode layer 2, a part of the electrode layer 2 is also electrolytically etched (FIG. 9D).
[0095]
Next, the first mask layer 3 in a region not covered with the second mask layer 7 is removed with a mixed aqueous solution of hydrofluoric acid and ammonium fluoride (FIG. 9E). Further, the second mask layer 7 is removed with acetone and dimethylformamide.
[0096]
In the material used in the present embodiment, the mask layer 6 is fixed to the electrode layer 2 relatively firmly at this stage, so that it can be used as a mold or a mold master.
[0097]
However, in the present example, the next stage was advanced. Again for the substrate (PSG mask layer 3 in the region of use is not removed since it does not interfere with the subsequent process, but rather strengthens the fixing of the hemispherical structure 8) Using Ni plating bath consisting of boric acid and brightener, bath temperature 60 ° C, cathode current density 40A / dm²Then, Ni plating is performed and grown until the adjacent first plating layers 6 are completely connected. By doing so, a hemispherical structure array having 700 × 700 hemispherical structures 8 could be formed (FIG. 9F). The in-plane distribution of the radius of curvature of the hemispherical structure 8 was within 5%.
[0098]
Thereafter, in the same manner as in the first example, a microlens array mold or a mold master was manufactured by the process shown in FIG. Also in this convex microlens array 15, the in-plane distribution of the lens diameter was within 5%.
[0099]
(Sixth embodiment)
A sixth embodiment will be described with reference to the manufacturing process diagram of FIG. The process is the same as in the first embodiment until the opening 4 is formed. The opening 4 has a circular shape with a diameter of 5 μm and a distance between adjacent openings 4 of 18 μm. In the present embodiment, a total of 3900 × 3900 openings 4 are provided (see FIG. 1A).
[0100]
Using the substrate 1 as a workpiece, the first plating layer 6 is grown until the hemispherical structure 8 having a radius at the center of the array of about 10 μm is the same as in the first embodiment (FIG. 1B). )reference).
[0101]
Next, a mask layer 7 made of a body-type photoresist (AzP4620: manufactured by Hoechst) is formed (FIG. 1C). The photoresist is exposed and developed, and a second mask layer 7 is selectively provided on 1064 × 808 regions excluding the peripheral portion 5 of the wafer.
[0102]
Subsequently, using the substrate 1 as a work, using as a positive electrode a nickel plating bath made of nickel sulfate, nickel chloride, boric acid and brightener, the bath temperature is 60 ° C., and the anode current density is 8 A / dm.²Then, the exposed first plating layer 6 is electrolytically etched.
[0103]
Next, by removing the first and second mask layers 3 and 7 with acetone and dimethylformamide, a hemispherical structure array having 1064 × 808 hemispherical structures 8 could be formed ( (Refer FIG.1 (e)). At this time, the in-plane distribution of the radius of the hemispherical structure 8 was within 5%.
[0104]
Next, Ni electroless plating is performed at a bath temperature of 90 ° C. using an electroless Ni plating solution (S-780: manufactured by Nippon Kanisen Co., Ltd.) containing a hypophosphite reducing agent, and the second plating layer 9 is formed (see FIG. 1F). As a result, the first plating layer 6 is firmly fixed on the electrode layer 2, and the electroless plating is used to form the second plating layer 9, thereby providing a highly glossy microlens array mold or mold master. was gotten. Further, the radius of curvature of each plating layer in the diagonal direction and the horizontal direction is almost equal, the average curvature radius is 20 μm, the distribution of the curvature radius is within ± 1 μm, and the gold having the hemispherical structure 8 having a uniform shape. A mold master could be formed.
[0105]
As described above, the present embodiment provides a manufacturing method that can easily reduce the in-plane distribution of the size of the hemispherical structure 8 in a microlens array mold or mold master using electroless plating. I was able to.
[0106]
Next, a mold release agent (Nikkanon Tack: manufactured by Nippon Chemical Industry Co., Ltd.) is applied. Using this substrate as a cathode, a Ni plating bath composed of nickel sulfamate, nickel bromide, boric acid and a brightener was used. The bath temperature was 50 ° C., the cathode current density was 5 A / dm.²Then, Ni electroplating is performed to form a mold. Thereafter, the mold is released from the substrate to form a microlens array mold.
[0107]
After the ultraviolet curable resin 12 is applied to the microlens array mold, a glass substrate serving as a support substrate 13 is placed thereon, cured by ultraviolet irradiation, and then peeled off to produce a convex microlens array 15. (See FIGS. 5 (e) and 5 (f)). Also in this convex microlens array, the in-plane distribution of the lens diameter was within 5%.
[0108]
(Seventh embodiment)
A seventh embodiment will be described with reference to the manufacturing process diagrams of FIGS. A silicon wafer having a diameter of 5 inches and having a silicon dioxide film with a thickness of 1 μm formed on both surfaces by using an oxidizing gas is used as the substrate shown in FIG. An electrode layer 2 is formed on this wafer by continuously forming 50% and 50% of Ti and Pt respectively by vacuum sputtering, which is one of thin film forming methods. A positive photoresist (Az1500: manufactured by Hoechst) is applied thereon to form the first mask layer 3.
[0109]
Next, the photoresist 3 is exposed and developed by photolithography to partially expose the electrode layer 2 and form the opening 4. The opening 4 has a circular shape with a diameter of 5 μm, a distance from the adjacent opening 4 of 18 μm, and is provided in an array in a region of 145 mmφ in the silicon wafer surface.
[0110]
Using this substrate 1 as a work, using an Ni plating bath composed of nickel sulfate, nickel chloride, boric acid and a brightener with the electrode layer 2 as a cathode, a bath temperature of 69 ° C., a cathode current density of 40 A / dm²Ni plating is performed. The first plating layer 6 made of Ni first deposits and grows from the opening 4, spreads on the first mask layer 3, and has a hemispherical shape with a radius of about 10 μm at the center of the formation surface of the first plating layer 6. The first plating layer 6 is grown until the structure 8 is obtained.
[0111]
Next, a mask layer 7 made of a positive photoresist (AzP4620: manufactured by Hoechst) is formed (FIG. 1C). The photoresist is exposed and developed, and a second mask layer 7 is selectively provided on the region excluding the peripheral portion 5 of the wafer. Here, as shown in FIG. 10, the second mask layer 7 has 1064 × 808 areas in the same plane and is provided at 8 locations with an interval 25 of 1.8 mm, and a marker used for alignment such as bonding. For the formation of 14, the second mask layer 7 is formed at an arbitrary position other than the 1064 × 808 regions. In FIG. 10, the second mask layer 7 for forming the marker 14 is provided at four locations near the four corners of each region. Therefore, at the interval 25, four second mask layers 7 for forming the marker 14 are formed, which is difficult to see in FIG.
[0112]
Using this substrate 1 as a workpiece and using it as an anode, a nickel plating bath made of nickel sulfate, nickel chloride, boric acid and a brightener, bath temperature 60 ° C., anode current density 8 A / dm²Then, the exposed first plating layer 6 is subjected to electrolytic etching (FIG. 1D).
[0113]
Next, by removing the first and second mask layers 3 and 7 with acetone and dimethylformamide, the marker 14 composed of 1064 × 808 hemispherical structures 8 and the first plating layer 6 is placed in the same plane. It was possible to form an array of hemispherical structures having eight. At this time, the in-plane distribution of the radius of the hemispherical structure 8 within each region and between the regions was within 5%.
[0114]
Next, Ni electroless plating is performed at a bath temperature of 90 ° C. using an electroless Ni plating solution (S-780: manufactured by Nippon Kanisen Co., Ltd.) containing a hypophosphite reducing agent, and the second plating layer 9 is formed (FIG. 1F). As a result, the first plating layer 8 is firmly fixed on the electrode layer 2, and the electroless plating is used to form the second plating layer 9, thereby providing a highly glossy microlens array mold or mold. Master was obtained. In addition, the radius of curvature of each plated layer in the diagonal direction and the horizontal direction is substantially equal, the average radius of curvature is 20 μm, the distribution of the radius of curvature is within ± 1 μm, and the hemispherical structure 8 has a uniform shape. A mold master could be formed (see FIG. 10).
[0115]
As described above, according to the present embodiment, the in-plane distribution of the size of the hemispherical structure can be easily reduced in the microlens array mold or mold master using the electroless plating by forming a plurality of regions together with the markers. It was possible to provide a manufacturing method that can be used.
[0116]
Next, a release agent for electroforming (Nikkanon Tack: manufactured by Nippon Chemical Industry Co., Ltd.) is applied. Using this substrate as a cathode, a Ni plating bath composed of nickel sulfamate, nickel bromide, boric acid and a brightener was used. The bath temperature was 50 ° C., the cathode current density was 5 A / dm.²Then, Ni electroplating is performed to form a mold. Thereafter, the mold was released from the substrate to form a microlens array mold. As a result, a microlens array mold capable of forming eight convex microlens arrays having the markers 14 from one mold was formed.
[0117]
After applying the ultraviolet curable resin 12 to the microlens array mold, a glass substrate to be the support substrate 13 is placed thereon, cured by ultraviolet irradiation and then peeled off, and each region is cut off to obtain one sheet. Eight convex microlens arrays 15 can be produced from the mold (see FIGS. 5E and 5F). Also in this convex microlens array, the in-plane distribution of the lens diameter was within 5%.
[0118]
【The invention's effect】
As described above, according to the present invention, a microlens array mold or mold that is easy to enlarge, easy to manufacture, has high controllability, is inexpensive, and has a small in-plane distribution in the array. A master and a manufacturing method thereof could be provided.
[0119]
Further, the first plating layer removed by the electrolytic etching can be recovered in the plating solution or the counter electrode metal material, and even an expensive metal material can be used without waste, and cost reduction can be realized. In addition, one, a plurality, or a plurality of types of microlens array molds or mold masters in which variation in size of each lens-forming hemispherical structure is suppressed are formed on a single substrate surface. did it.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a manufacturing process of a microlens array mold or mold master according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a cross-sectional state and a top surface state in step (b) of FIG. 1;
FIG. 3 is a diagram showing a cross-sectional state and a top surface state in step (c) of FIG. 1;
4 is a view showing a cross-sectional state and an upper surface state in step (e) of FIG. 1; FIG.
FIG. 5 is a cross-sectional view illustrating a manufacturing process of a microlens array mold, a mold master, a microlens array, and the like according to the first embodiment of the present invention.
FIG. 6 is a top view showing a part of a manufacturing process of a microlens array mold or a mold master according to a second embodiment of the present invention.
FIG. 7 is a top view showing a part of a manufacturing process of a microlens array mold or a mold master according to a second embodiment of the present invention.
FIG. 8 is a partially broken top view showing a convex microlens array with markers according to a second embodiment of the present invention.
FIG. 9 is a cross-sectional view illustrating a manufacturing process of a microlens array mold or mold master according to a fifth embodiment of the present invention.
FIG. 10 is a top view showing a part of a manufacturing process of a microlens array mold or a mold master according to a seventh embodiment of the present invention.
FIG. 11 is a diagram for explaining a microlens array mold according to the prior art.
[Explanation of symbols]
1 Substrate
2 Electrode layer
3 First mask layer
4 openings
5 Array periphery
6 First plating layer
7 Second mask layer
8 Hemispherical structure
9 Second plating layer
10 Sacrificial layer
11 Electrode layer for mold formation
12 UV curable resin
13 Support substrate
14 Markers
15 Convex microlens array
20 Mold
25 intervals

Claims (18)

A method for manufacturing a microlens array for mold master,
(1) preparing a substrate having a conductive portion at least in part;
(2) forming an insulating first mask layer on the substrate;
(3) forming a plurality of appropriately shaped openings in the first mask layer to expose the conductive portions;
(4) forming a first plating layer on the opening and the first mask layer through the opening by electroplating using the conductive portion as a cathode;
(5) forming an insulating second mask layer on the opening and a selected region of the first plating layer;
(6) removing the first plating layer in the region where the second mask layer is not formed by electrolytic etching by applying a voltage using the conductive portion as an anode;
And after the step (6),
(7) a step of removing the first mask layer entirely after removing the second mask layer;
Or
(8) removing the second mask layer after removing the first mask layer that is not covered by the second mask layer while leaving the second mask layer;
Any of the steps,
(9) forming a second plating layer or electrodeposition layer from the first plating layer to the conductive portion;
Furthermore a method for manufacturing a microlens array for mold master with. The method for manufacturing a first mask layer is PSG a is as defined in claim 1 microlens array for mold master. The method for manufacturing a second plating layer is electroless plating or according to claim 1, formed by electroless plating microlens array for mold master. Microlens manufacturing method of the array for mold master of claim 1 where the second plating layer made of nickel plated layer. Microlens manufacturing method of the array for mold master according to claim 4, the second nickel-plated layer is formed of an electroless plating layer. The method for manufacturing a microlens array for mold master according to claim 4 or 5 phosphorus is contained in the second nickel plated layer. The method for manufacturing a microlens array for mold master according to any one of claims 1 to 6 wherein the openings are arranged in a periodic repetition sequence pattern in the substrate surface. Manufacturing method of the step (4) in the first plating layer, each separated according to any of claims 1 to 7 are formed by a microlens array for mold master. Manufacturing method of the step (5) in the second mask layer according to any one of claims 1 to 8 is formed in a plurality of regions microlens array for mold master. A plurality of regions microlens manufacturing method of the array for mold master of claim 9 including a plurality of regions covering the first plating layer of each identical sequence of the second mask layer in the step (5). Manufacturing method of the step (5) in the second plurality of regions of the mask layer are each different from the sequence of a first of claim 9 including a plurality of regions covering the plating layer microlens array for mold master. Wherein step (5) in the second of the first claim is around 2mm or more regions of the plated layer 1 to 11 in which the width of the area of the first plating layer not covered by the mask layer is covered with the mask layer microlens manufacturing method of the array for mold master according to any one. Wherein step (5) a second first microlens array for molds according to any one of claims 1 to 12 in-plane distribution of the diameter of the plated layer is within 5% of the area covered by the mask layer in the Master production method. According to a partial region of the first plating layer covered by the second mask layer, any one of claims 1 to 13 is intended for forming a first plating layer which is a marker for alignment the method for manufacturing a microlens array for mold master. A method for manufacturing the electrolytic etching is step (4) of claims 1 to 14 carried out in the plating bath as used in according to any microlens array for mold master. Material of the first plating layer formed in the material and the step of the conductive portion which acts as the electrode (4) is, for microlens array according to any one of claims 1 to 15 which is a material that does not form an alloy layer Manufacturing method of mold master. The material of the conductive portion serving as the electrode and the material of the first plating layer formed in the step (4) do not form an alloy layer by the diffusion of the conductive partial material toward the first plating layer. microlens manufacturing method of the array for mold master according to any one of claims 1 to 16 which is a material. The material of the conductive portion serving as the electrode and the material of the first plating layer formed in the step (4) are formed such that the first plating layer material diffuses toward the conductive portion to form an alloy layer. microlens manufacturing method of the array for mold master according to any one of claims 1 to 15 which is a material.

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