JP2009251082A - Method for manufacturing electroforming mold and hologram - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a mold facilitating duplicating a relief pattern in a high aspect ratio without deformation, and particularly, a method for manufacturing an embossing mold for a relief hologram and a hologram. <P>SOLUTION: The method for manufacturing a mold includes steps of: forming a seed layer on an original where a pattern is formed, under the conditions of film formation that an internal stress σ satisfies -3.0 N/m<SP>2</SP><σ<3.0 N/m<SP>2</SP>; and electroforming by using the seed layer as an electrode. The method for manufacturing a hologram includes duplicating the original to obtain a master plate, further duplicating the master plate to obtain a mother plate, duplicating the mother plate to obtain a stamper and embossing a hologram pattern by using the stamper, wherein the original is a relief hologram original and the master plate is manufactured by the above method for manufacturing a mold. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a mold having a fine and high aspect ratio relief shape such as a mold for an embossed hologram, and in particular, without reducing the transfer rate of a relief cross-sectional shape from an original plate having an aspect ratio of 1.0 or more. The present invention relates to a method for producing a mold by casting duplication.

  A hologram in which an uneven interference fringe pattern is formed on the surface of a resist or the surface of a resin is widely known as a relief hologram. In a general method for producing a hologram product, a master plate is duplicated by electroforming from an original plate, a mother plate is duplicated from a master plate, a stamper is duplicated from the mother plate, and a substrate is formed using the stamper. The relief is transferred to the film using heat or UV light on the coating layer. After that, aluminum or the like is deposited on the relief surface to produce a reflection type hologram product.

  A method for producing a stamper from this hologram master will be described with reference to the drawings. When producing the hologram original plate 7 of FIG. 1, a resist is applied to a well-polished glass plate 2 with good flatness and dried, and the hologram 1 is photographed with laser light, and further, the unevenness 1 corresponding to interference fringes is produced by development. Or, an EB drawing apparatus is used to draw an electron beam and develop it to produce the irregularities 1 corresponding to interference fringes. When the master plate 4 whose shape is inverted from the hologram original plate 7 is duplicated by plating, the seed layer 3 is produced by using silver mirror reaction, electroless plating, metal vapor deposition, or sputtering. When the mother plate 5 is duplicated from the master plate 4, the surface of the master plate 4 is peeled off, and the mother plate 5 is duplicated by electroforming. Further, the stamper 6 is peeled off from the mother plate 5 and is duplicated by electroforming.

  The master plate 19 from the resin plate 25 that is multi-faced by using the stamper 6 that has been duplicated from the mother plate 5 is subjected to a silver mirror reaction as a seed layer 17 in the same manner as the master plate 4 is duplicated from the hologram master plate 7. Electroless plating, metal vapor deposition, or sputtering is used. In order to duplicate the mother plate 21 from the master plate 19, the surface of the master plate 19 is peeled and the mother plate 21 is duplicated by electroforming. Further, the stamper 23 performs a peeling process on the surface of the mother plate 21, and is duplicated by electroforming.

  By the way, in patent document 1, since the uneven | corrugated shape of a relief collapse | crumbles by plating and a faithful duplicate cannot be obtained, and since only one master version is duplicate, it has good peelability after curing on a photoresist having an uneven pattern. Relief hologram by applying uncured liquid of ultraviolet curable resin, curing by irradiating with ultraviolet light, then peeling from photoresist, producing resin master plate, and repeating the duplication process one or more times from this resin plate A method for producing an embossing mold has been devised.

  As described above, in the conventional method of reprinting a mold, especially for a hologram having a deep relief and a high aspect ratio, the master plate 4 after plating or the multi-surface imprinting using the master plate 4 is performed. The relief depth of the master plate 25 becomes shallow and the transfer rate ((depth of the master plate relief portion / depth of the original plate relief portion) × 100) often decreases, and the diffracted light intensity also decreases. there were.

Japanese Patent Laid-Open No. 5-35173

  The present invention has been made for the above-described problems. Accordingly, an object of the present invention is to provide a method for manufacturing a mold, particularly a method for manufacturing an embossing mold for a relief hologram, which can be duplicated without deforming a relief shape having a high aspect ratio.

  In order to solve the above-mentioned problems, the present inventors have repeated experiments under various conditions, and the metal thin film has a stress value within a predetermined value as a seed layer on an original plate such as a relief hologram original plate or a multi-sided resin original plate. By forming the film in this way, it was discovered that a metal mold can be produced by electroforming without duplication of the relief cross-sectional shape.

  That is, the present invention manufactures an embossing die for a relief hologram, in which a master plate is duplicated from an original plate while forming a film on the original plate with minimal stress accumulation inside the seed layer, and a metal die is duplicated by electroforming. Is the method.

  In the present invention, a seed layer is formed on the surface of the original plate, and only by setting the film forming conditions, electroforming can be performed without causing a change in the cross-sectional shape of the high-aspect-ratio original plate, and the production method of the present invention is used. The mold hologram can be applied to various security-related products and other fields. Further, the mold manufacturing method of the present invention can be applied to the master plate without reducing the transfer rate of the relief cross-sectional shape, even for a high-aspect original plate having an aspect ratio (relief depth / relief diameter) of 1.0 or more. Can be duplicated.

  First, a method for applying the seed layers 3 to 17 to the relief hologram master and the multi-faced resin master will be described. The application method includes sputtering and vapor deposition, which are dry plating, and wet electroless plating. The most desired properties of the seed layers 3 to 17 are that they do not peel off during plating and can be duplicated without deformation as the original plate.

  As shown in FIG. 1, the master plate can be duplicated by forming the seed layer 3 on the original plate 7 on which the relief is formed, and performing electroforming using this seed layer as an electrode. The seed layer is a metal plating film by dry or wet plating as will be described later.

  Usually, a metal plating film formed by a dry method or a wet method has stress (internal stress) in the film. Due to the magnitude of this internal stress (hereinafter simply referred to as stress), the shape of the original plate is deformed, and peeling from the resist or resin surface occurs in the early stage of electroforming, which greatly affects the quality of electroforming. However, after electroforming, it is difficult to detect a quantitative stress value when the seed layer is formed.

Therefore, the present inventors examined a method for minimizing the stress of the metal thin film that becomes the seed layer and minimizing the deformation of the original surface. As a result, by controlling the deposition conditions, that the internal stress sigma of the seed layer and ^{-3.0N / m 2 <σ <3.0N} / m 2, can be excellent mold production resulting transfer rate discovered.

  The negative range of the stress corresponds to compressive stress, and the positive range corresponds to tensile stress. As a method for measuring the stress of the film, the Newton ring method can be used as described in the following examples. For simplicity, a metal plating film may be formed on a substrate such as a PET film cut to a certain size under the same film formation conditions as the seed layer, and the degree of relative curl may be examined.

  Specifically, when the seed layer is formed by dry plating, the pressure inside the bell jar during sputtering or vapor deposition, the deposition rate, and the control of the film thickness are proportional to the atomic weight of the metal forming the seed layer. Therefore, it is necessary to increase the gas pressure in the bell jar during sputtering. In electroless plating, the stress inside the film can be reduced by controlling the film formation rate and film thickness, and when using the silver mirror reaction, by controlling the film thickness.

  In order to form a seed layer on the original plate by reducing the stress by sputtering, the stress of the film can be reduced if the pressure in the bell jar and the film formation speed during sputtering are kept constant. Also, when the seed layer is formed by vapor deposition, the stress of the film can be reduced if the pressure in the bell jar during vapor deposition is set to a certain pressure. The metal for forming the seed layer by sputtering or vapor deposition can be any of chromium, silver, copper, nickel, iron, and platinum. Table 1 shows specific examples of film forming conditions for silver, chromium, and copper.

  Furthermore, when forming electroless plating as a seed layer on an original plate, the deposition rate is important, and it is good to maintain a deposition rate of 0.3 to 0.4 nm / second. It is necessary to manage the liquid temperature. Any type of electroless plating can be used, such as copper, nickel, and silver.

As described above, the original plate on which the seed layer is formed is set on an electroforming jig, and a master plate having a thickness of 100 to 300 μm is duplicated. The plating solution composition is nickel sulfamate 400 to 650 g / L, nickel chloride 5 g / L, boric acid 30 to 45 g / L, and an appropriate amount of pit inhibitor. The plating solution temperature is in the range of 35 to 55 ° C., and the current density can be 3 to 6 A / dm ² .

  Examples of the present invention will be described in detail below. However, the present invention is not limited to the following examples.

<Example 1>
When a seed layer is formed on the relief hologram master 7 by sputtering, silver is used as a sputtering target, the relief hologram precursor 7 is set in a bell jar, deaerated in advance, and Ar gas is introduced at 1 × 10 ⁻³ Pa or less. The film was formed so that the internal pressure of the bell jar was 1.0 Pa, the film formation rate was 0.5 nm / second, and the film thickness was about 70 nm. Even when a silver film was applied to a PET film cut to a certain size under the same conditions, a curl-free product was obtained. Furthermore, verify that the same stress of the film produced in the film formation conditions sigma and 10 samples measured, which is both -3.0N / ^{m 2} <σ <and 3.0 N / ^{m 2} by a Newton ring method described below did.

Thereafter, the relief hologram original plate 7 was taken out from the sputtering apparatus, set in a dedicated electroforming jig, placed in the above-described nickel sulfamate electroforming bath, and electrocasted to about 300 μm.

  After the electroforming is completed, the electroforming jig is taken out from the plating solution, the relief hologram master 7 and the master plate 4 are peeled off, the resist on the surface of the master plate 4 is removed, and the unevenness of the relief portion is removed by AFM (Atomic Force Microscope, atoms). When the height was measured using an atomic force microscope, the master plate 4 with no relief deformation compared to the original plate 7 was duplicated.

<Example 2>
When a seed layer is formed on the relief hologram master 7 by sputtering, chromium is used as a sputtering target, the master 7 is set in a bell jar, degassed in advance to 1 × 10 ⁻³ Pa or less, and Ar gas is introduced. The film was formed so that the internal pressure of the bell jar was 0.3 Pa, the film formation rate was 0.35 nm / second, and the film thickness was about 25 nm. The stress sigma of film produced in the same film forming conditions was 10 samples measured, it was confirmed that both has a ^{-3.0N / m 2 <σ <3.0N} / m 2.
Thereafter, the relief hologram original plate 7 was taken out from the sputtering apparatus, set in a dedicated electroforming jig, placed in the above-described nickel sulfamate electroforming bath, and electroformed to about 300 μm.

  After the electroforming is completed, the electroforming jig is taken out from the plating solution, the relief hologram master 7 and the master plate 4 are peeled off, the resist on the surface of the master plate is removed, and the unevenness of the relief portion is removed by AFM (Atomic Force Microscope, interatomic When the height was compared with that of the original plate 4 by a force microscope, the irregularities as in the original plate were transferred.

<Example 3>
When a seed layer is formed on the relief hologram master 7 by sputtering, copper is used as a sputtering target, the relief hologram precursor 7 is set in a bell jar, deaerated in advance to 1 × 10 ⁻³ Pa or less, and Ar gas is introduced. The film was formed so that the internal pressure of the bell jar was 0.3 Pa, the film formation rate was 0.35 nm / second, and the film thickness was about 55 nm. The stress sigma of film produced in the same film forming conditions was 10 samples measured, it was confirmed that both has a ^{-3.0N / m 2 <σ <3.0N} / m 2.

  Thereafter, the relief hologram original plate 7 was taken out from the sputtering apparatus, set in a dedicated electroforming jig, placed in the above-described nickel sulfamate electroforming bath, and electrocasted to about 300 μm.

  After the electroforming is completed, the electroforming jig is taken out from the plating solution, the relief hologram master 7 and the master plate 4 are peeled off, the resist on the surface of the master plate is removed, and the unevenness of the relief portion is removed by AFM (Atomic Force Microscope, interatomic When the height was compared with that of the original plate using a force microscope), the irregularities as in the original plate were transferred.

<Example 4>
When the seed layer is formed on the relief hologram master 7 by electroless nickel plating, after forming a palladium nucleus on the relief hologram master 7, the film formation speed in an electroless nickel bath using sodium phosphite as the reducing agent The film thickness was set to 0.3 to 0.4 nm / second, preferably 0.35 nm / second, and the film thickness was about 25 nm. The stress sigma of film produced in the same film forming conditions was 10 samples measured, it was confirmed that both has a ^{-3.0N / m 2 <σ <3.0N} / m 2.

  Thereafter, the relief hologram master 7 was taken out of the electroless nickel plating bath, set in a dedicated electroforming jig, and placed in the above-described nickel sulfamate electroforming bath, and electrocasted to about 300 μm.

  After electroforming is completed, the plate is removed from the plating solution, the relief hologram master 7 and the master plate 4 are peeled off, the resist on the surface of the master plate 4 is removed, and the unevenness of the relief is removed by an AFM (Atomic Force Microscope). Comparing the height with the original, the unevenness as the original was transferred.

<Example 5>
When a seed layer is formed on the multi-sided resin original plate 25 produced using the stamper 6 by sputtering, chromium is used as a sputtering target, the multi-sided resin original plate 25 is set in a bell jar, deaerated beforehand, and 1 × 10 ^{− The} pressure was ³ Pa, Ar gas was introduced, the bell jar internal pressure was 0.3 Pa, the film formation rate was 0.35 nm / second, and the film thickness was about 25 nm. The stress sigma of film produced in the same film forming conditions was 10 samples measured, it was confirmed that both has a ^{-3.0N / m 2 <σ <3.0N} / m 2.

  Thereafter, the multi-sided resin original plate 25 was taken out from the sputtering apparatus, set in a dedicated electroforming jig, placed in the above-described nickel sulfamate electroforming bath, and electroformed to about 300 μm.

  After the electroforming is completed, the electroforming jig is taken out from the plating solution, the multi-sided resin original plate 25 and the master plate 19 are peeled off, the resist on the surface of the master plate 19 is removed, and the unevenness of the relief portion is removed by AFM (Atomic Force Microscope, When the height was compared with that of the original plate using an atomic force microscope), the unevenness as in the original plate was transferred.

<Measurement method of stress by Newton ring method>
A sputtered film is formed on a thin disc-shaped quartz substrate (diameter 30 mm, plate thickness 0.1 mm), light with a wavelength of 632.8 nm is applied to the semitransparent mirror, and the reflected light is behind the semitransparent mirror. The stress was measured using the following formula from the amount of deformation of the distortion.
^{σ = Eb 2/6 (1} -ν) rd
Where E: Young's modulus (Pa) of substrate, b: thickness of substrate (m), ν: Poisson's ratio of substrate, d: thickness of thin film (m), r: radius of curvature (warp of substrate) (m ). An existing thin film stress measuring device was used for the measurement.

FIG. 3 is a diagram showing a duplicate plate with a seed layer attached to the relief hologram master of the present invention. It is a figure which shows duplicating a multi-sided master plate from the multi-sided original plate produced using the stamper 6 of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Resist relief, 2 ... Glass plate, 3 ... Seed layer, 4 ... Master plate, 5 ... Mother plate, 6 ... Stamper, 7 ... Relief hologram original plate, 10 ... Residential relief resin, 13 ... Primer layer, 15 ... Glass plate, 17 ... Seed layer, 19 ... Multi-imposition master plate, 21 ... Other imprint mother plate, 23 ... Multi-sided stamper, 25 ... Other sided resin master

Claims (6)

A step of on original plate pattern is formed internal stress sigma forming a seed layer at a deposition condition becomes ^{-3.0N / m 2 <σ <3.0N} / m 2, electroforming the seed layer as an electrode And a mold manufacturing method.   2. The mold manufacturing method according to claim 1, wherein the step of forming the seed layer is film formation by sputtering, vapor deposition, or wet plating.   3. The mold manufacturing method according to claim 1, wherein the seed layer is made of any one of silver, gold, chromium, nickel, iron, and platinum.   4. The mold manufacturing method according to claim 1, wherein a master plate is duplicated from an original plate having an aspect ratio of 1.0 or more.   The method for producing a mold according to claim 1, wherein the mold is a hologram mold. In a method of manufacturing a hologram, a mother plate is duplicated from a master plate, a stamper is duplicated from the mother plate, and a hologram pattern is embossed by the stamper.
6. A hologram manufacturing method, wherein the original plate is a relief hologram original plate, and a master plate is manufactured using the mold manufacturing method according to claim 1.

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